Drainable ferrule valve design
An apparatus for inoculating a sample to or withdrawing a sample from a vessel or conduit includes a body with an internal sample cavity, a valve operating rod movable to open and close an orifice to the sample cavity and a coupler to attach the body to a port of the vessel or conduit. A portion of the sample cavity is formed by an endcap which includes the orifice. The sample cavity is thermally and/or electrically insulated from the vessel or conduit. This insulation can arise from an empty or filled space between an inner wall and outer wall of the valve. Otherwise, insulating material can be used in forming the valve. The valve can be mountable on the vessel or conduit such that a positive drain angle is maintained regardless of whether the ferrule to the vessel or conduit is inclined upwardly, downwardly or is horizontal.
This application is a Continuation of co-pending application Ser. No. 09/688,143, filed on Oct. 16, 2000, which is a continuation-in-part of U.S. application Ser. No. 09/122,629, filed Jul. 27, 1998, now U.S. Pat. No. 6,133,022, which is a continuation-in-part of U.S. application Ser. No. 08/613,586, filed Mar. 12, 1996, now U.S. Pat. No. 5,786,209, which is a divisional of U.S. application Ser. No. 08/215,416, filed Mar. 21, 1994, now U.S. Pat. No. 5,525,301, which is a continuation-in-part of U.S. application Ser. No. 07/911,052, filed Jul. 9, 1992, now U.S. Pat. No. 5,296,197, the entire contents of each of these applications is hereby incorporated by reference.
BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention relates to an automated sample extractor or feeder/inoculator and a removable manual override operator for a vessel or conduit. This vessel or conduit can be a bioreactor or other similar equipment.
2. Description of the Background Art
Development of new or more efficient commercialization of existing products requires faster and more effective methods to measure process variables. This is particularly true in processes which require cell culture and fermentation processes conducted in bioreactors where the accuracy of measurements in the research and development are critical for achieving economic production of high purity and highly refined end products.
Some factors which must be controlled include temperature and pressure. These factors are easily measured by utilizing standard sensors. However, many other factors can be measured only by removing samples for external laboratory analysis. The frequency of sample extraction for testing and measurement, number of tests on each sample and the time constraints on the process vary widely as do the methods and equipment used to obtain the samples.
In most cases, measurement processes for variables do not lend themselves to in-situ measurement by remote sensors directly in the process. Instead, samples must be physically extracted from the process and examined and manipulated outside the vessel or conduit. Before this examination and manipulation process can be carried out, a safe, effective means of sample extraction must be made available. By “safe” here we mean that the process should remain as unaffected by the act of taking a sample as possible as the sample itself should. Besides being safe and effective, the means of sample removal should also take into consideration that the character of sample material taken from one place is very likely to differ from that taken from another place. Therefore, it is important to provide a means by which sample material can be removed from the vessel from a location where its character correlates well with information being derived from in-situ sensor measurements as well as with the character of the bulk of the process material. As such the means for removing material would best be one that also can be flexibly incorporated new or existing systems such as into existing (angled) ferrules and, at the same time, provide a means of sampling the process in the same area as is sampled by other in-situ measurement sensors.
The prior art provides for removal of sample material but does not provide features that could adequately address issues concerning the quality of the material as a representative sample of the process nor the ability to be effectively incorporated into existing system. Many of the prior art designs do not lend themselves easily to use as a retrofit but, instead, require substantial modification to the system for installation or repositioning. An apparatus should minimize or eliminate the dangers associated with the sampling process in an efficient and cost effective manner while providing quality, reproducible results in order to be of value for commercial application.
When working with samples, especially hazardous samples, it is necessary to remove or feed/inoculate material without endangering the integrity of the process, subsequently sampled material, the operator or the outside environment. Many prior art devices are unsatisfactory in this area.
Also, some prior art systems are not automated. Therefore, there is potential danger posed by human procedural errors which could easily result in operator and environmental exposure. Accordingly, a need exists for an automatable apparatus with the capacity for independent verification of equipment operation built in.
There is a need for an automated system which offers a quick, easy-to-use means to override the automation apparatus. Sampling is most important in processes of which relatively little is known. The apparatus should be one that is easily incorporated into new and existing systems in one or more places in a cost-effective way, allowing material to be removed or added to the process at multiple points so that the optimal means for monitoring and controlling the process can be established. Once defined, unnecessary or redundant devices should be easily removed from the process without adversely affecting the process but these devices should, ideally also remain intact and unaffected so that they may be readily used again in other process development, monitoring and control applications.
There always is a need to collect unanticipated samples. In providing this means, it is critical that the apparatus should be able to provide essentially identical samples in either case (i.e. manual or automated mode). Furthermore, the materials being sampled themselves are often expensive. Therefore, excessive removal of sample should be avoided. In the existing art, rotating cams and rotating knobs or handwheels are usually the means employed to open and close sampling valves. These designs require the operator to move their arm or, at least their hand, through a range of motion of 90-180 degrees or more. In the very best conditions this motion will take at least 1.0 second to perform a full cycle (open and close). Since most sample port apertures are 5 mm or more in diameter, it is very likely that 30 ml or more of process material will flow out between the time the valve is opened and closed. Usually the volume of sample required is small, often 50 ml or less.
As a consequence, one of two events occurs. Either a relatively large amount of sample material is wasted or the technician must resort to “throttling” the valve (partially opening it). Since process material is either valuable, hazardous or there is a need for cleanliness, there is a tendency of technicians to resort to throttling the valve to more carefully and accurately control the flow of sampling material. However, “throttling” can significantly alter the sample in two important ways.
First, the smaller, more fluid elements of the sample will more easily pass through the constricted opening rather than the larger, more viscous elements. The result is a selective removal, or sieving out, of the larger, more viscous elements from the sample.
Second, those elements that do pass through the crevice will have been subjected to high levels of shear, possibly significantly altering their physical and chemical properties, changing them from the desired representative subsample of process populations and conditions.
An effective means to minimize this effect will require the valve to be opened to a full open position until enough sample is drawn at which time the valve must be rapidly closed. Automated actuation using electromagnetic solenoids or pneumatic actuators which have only two position, “open” or “closed”, are much more preferable over “throttling” or “positioning” actuators.
Likewise, to eliminate sample bias in a manually operated valve, a manual motion which can be rapidly translated into full articulation of the operating rod from fully “closed” to fully “opened” and back must be realized. The fastest (articulating) elements in humans, besides the eyes, are the fingers. A “flick” or “snap” of the fingers takes a fraction of a second. Since most sample particles are much smaller than the range of motion used in a single flick of a finger, direct coupling of finger motion to actuation of the operating rod of the sampling valve presents an effective solution. Furthermore, because of the relatively small cross sectional area of sampling orifice and the relatively moderate pressures used in most (biological) manufacturing processes, little or no gear reduction will be required to overcome the tension of a “fail close” return spring operating on valve operating rod to close and form a seal at the orifice. The mechanism described here can easily and quickly be removably connected to valves with automated mechanisms. When manual sampling is necessary, trigger-action control can provide a more physically and chemically representative subsample of the process with more precise control of sampling volumes with less wasting of material.
When removing or adding material to a process, it is often desirable to maintain the aseptic integrity of the process as well as protect the surrounding environment. As such it is important that material from the previous removal or addition operation not contaminate the environment, the process or the current sample material. Loss of a sample run or contamination of the process can have extremely expensive ramifications. Therefore, it is important to add material or obtain a sample without the procedure causing contamination.
Many prior art devices permit accumulation or pooling of samples or cleansing medium. When the device is first used this may not create a problem; however, upon subsequent runs, the sample material or material added to the process through the device may be contaminated, or at least, diluted.
Additionally in the prior art, technology used for taking samples is generally unsatisfactory for feeding/inoculating the vessel or container.
SUMMARY OF THE INVENTIONAccordingly, it is a primary object of the present invention to provide an apparatus for moving flowable material either in an automated or manual fashion into a vessel or conduit (an inoculation apparatus) or to move flowable material from the vessel or conduit (a sample extractor).
It is an object of the present invention to provide an apparatus which can be retrofitted to existing standard tank port holes without requiring equipment modification.
It is the further object of the invention to provide means to retrofit the present invention into existing tanks port holes of different lengths or to be installed in a penetrating configuration, equivalent to other in-situ sensors.
Another object of the present invention is to provide an apparatus which will provide a representative subsample of the process composition which will better correlate with in-situ sensor measurements, even in applications involving heat labile or electrically sensitive materials.
It is a further object of this invention to provide an automated and manual means of sampling the process, the results of either being of equivalent quality and equally being representative of the process.
It is also an object of the invention to provide a means by which manual and automated operators can be added, removed or exchanged from the valve while it is in service and without jeopardizing the aseptic integrity of either the process or the outside environment.
Another object of the invention is to provide a device that has a safety catch so that the valve cannot accidentally be opened.
Furthermore, it is an object of the invention to provide within the same means a way to lock the valve in the open position to facilitate the taking of large volume of samples.
A further object of the apparatus is to provide a means by which samples can be safely and reliably taken automatically without having to worry about injury to someone who could be caught unaware standing near or up against the device when it automatically actuates. A corollary to this is that blockage to the mechanical elements and interference with sample taking is also avoided.
Still another object of the present invention is to eliminate or minimize the dangers of the sampling process such as contamination of the sample, process or surrounding environment.
It is a further object of the present invention to provide an apparatus which will conduct a sampling and maintain the sample in sealed arrangement such that there will be no danger to the sample itself or to the operator, the process and the surrounding environment.
Another object of the present invention is to provide an automatable system to eliminate operator error.
It is the object of the invention to provide means for effectively duplicating automated action in a manual override mechanism.
Yet another object of the present invention is to provide for a built-in verification of proper operation of the apparatus.
Still another object of the present invention is to provide a sample apparatus which avoids contact of the sample with dynamic (sliding or rotating) seals, thereby avoiding potential sites for accumulation of carryover contaminants.
A further object of the present invention is to eliminate the usual static crevice areas which may collect contaminates but yet are inaccessible to cleaning and sterilization agents and thus eliminates areas which might harbor carryover contaminants.
It is a further object of the present invention to avoid dead (stagnant) spaces in the apparatus which would result in samples that are not truly reflective of the process.
Yet another object of the present invention is to avoid obstacles or barriers to free drainage of the samples, not only when the device is installed in portholes with down-sloping or horizontal interior axes of orientation but also even when the device is installed in portholes with positive interior axes of orientation relative to horizontal.
Another object of the present invention is to provide a relationship that relates the diameter of the valve sampling orifice to the angle of orientation of the porthole's internal axis with horizontal, the porthole's internal diameter and the length of the porthole's internal bottom margin, providing a means to design valves to fit in existing portholes while maintaining the capability to be free-draining as does the invention in its latest embodiment.
Still another object of the present invention is to provide a flushing arrangement for the apparatus whereby contaminants and other material will be forced from the system.
Yet a further object of the present invention is to avoid excess process void volume inside the apparatus which would result in sample volume measurement difficulties and material wastage.
Still another object of the present invention is to avoid passive “breathing” between the seals of the apparatus and the outside environment.
Another object of the present invention is to provide an apparatus which can be repeatedly cleaned and/or sterilized in place.
A further object of the invention is to provide a means by which samples can be extracted from within the body of the process closer to where the sensors take their readings rather then at the margins (of vessels or conduits) where samples are taken as when using prior art devices.
It is an additional object of the invention to minimize the amount of thermal and/or electrical exchanged between the apparatus and the process within the vessel or conduit, especially during heat sterilization cycles, even though the device may be installed in a configuration where in the sampling orifice may be positioned well within the body of the process fluid.
Yet another object of the present invention is to provide an apparatus which can easily be removed and quickly disassembled for maintenance, including replacement of worn parts.
A further object of the present invention is to provide an apparatus whose materials are compatible with the sample materials and the process.
Yet another object of the present invention is to provide a low cost apparatus which can effectively carry out sampling or inoculation.
Still another object of the present invention is to provide an apparatus which will be reliable, easy to maintain and low cost.
Another object of the present invention is to provide multiple use capability of the apparatus including feeding/inoculation as well as sampling.
These and other objects of the present invention are fulfilled by providing an apparatus for moving a sample of flowable material through a port in a wall of a vessel or conduit. Thus, this apparatus can either feed in or withdraw materials.
The apparatus comprises a body having an internal cavity with an end wall and an orifice in that end wall. The valve body, walls near the end wall and the endwall, itself, may be at least one of hollow or coated or fabricated of at least one of a thermally or electrically insulating material. The purpose of the hollow, coated or insulating material character being one of isolating the thermal and/or electrical internal valve sterilization and/or operating process from the heat and/or electrically sensitive process material it may (from time to time) come into contact with. Means (a threaded collar or clamp, for example) which is fixed or adjustable in position along the body is provided for coupling the body to the port in the vessel or conduit. Where isolation of the process from the valve components is necessary, a diaphragm valve is positioned within the internal cavity of the body. Where a diaphragm is necessary to isolate the process, it would incorporate a sealing tip to close off the sampling orifice, said sealing tip being connected to and continues with a flexing diaphragm which can be removably anchored to the valve body so as to isolate the mechanical components and crevices from the process, two embodiments of the diaphragm valve being one with a diaphragm with a (blind) bulbous tip and a rubber bellows with a tubular body and a blunt sealing tip or one with a long shaft with a (blind) blunt sealing tip at one end and a (conical) flexing base at the other. The tip of the diaphragm can be moved to close or open the orifice. The body of the valve is spaced from the interior surfaces of the internal cavity to thereby define a sample cavity. This sample cavity is communicable with the orifice. A valve operating rod is attached to the blunt sealing tip and is moved by an appropriate drive to open and close the orifice.
The valve operating rod extends out the rear of the valve through a plate attached to the rear wall of the valve. This plate (may) include seals that isolate the valve interior from the outside environment.
A manual valve actuator, including a leverage adjustable trigger mechanism, a safety catch, a secondary return spring with spring tension adjustment and a stroke-limiting backstop, may be removable connected to the valve body and operating rod at the back of the valve. An automated actuator can also be removable added at the same point with the trigger mechanism being removed and, if desired, reattached onto the rear wall of the automated actuator. The valve operation, therefore, can be either manually or automatically driven, the manual method being one of a finger controlled trigger action mechanism while the automated method being one employing a pneumatic, electromagnetic or other acceptable means of actuation. The results in all cases are essentially the same back and forth articulation of the valve operating rod resulting in opening and closing of the valve.
An inlet passage leads to the sample cavity of the body. In some instances where cleaning and sterilizing can be performed through the sampling orifice, the inlet passage may be eliminated. In practice, if it is present, a restriction is that it also unobstructedly drain down to the drain hole and be connected with the internal cavity.
A drainage trough (or channel) formed in the (anterior portion of the) body leads away from the orifice in the sample cavity of the body to some lowest point within the internal cavity from which material may be drained out of the cavity. The bottom of this channel forms a path between the orifice and the drain opening, the path having an angle or; angles of declination to it so that, when installed in a ferrule, the angle of declination of the path is always greater than that of the ferrule. The sides and the rear wall of the internal cavity all have unobstructed paths that drain down to the drain opening exiting the valve which, when in combination with the forward drainage trough lead down to the drain opening lowest point in the internal cavity and form a drainage basin with unobstructed drainage capabilities over a wide range of installation angles. This drain trough or channel has a longitudinal axis which is noncoaxial with the longitudinal axis of the portion of the valve body which can be inserted into the porthole.
In one arrangement, steam, air and/or a wash medium can be supplied through the inlet passage, sample cavity and out the drain passage in order to clean the interior of the apparatus. With the tip of the valve moved to open the orifice, the sample can then be extracted from the vessel or conduit through the sample cavity and out the drain passage. This sample will be fed to means for collecting the sample.
When the apparatus is used for feeding or inoculating, material is normally fed through the inlet passage. This diaphragm valve is retracted and the feed or inoculate is forced through the inlet passage, past the diaphragm valve into the vessel or conduit.
In some case only one passage into or out of the valve is necessary in addition to the orifice. In these cases the washing and sterilizing of the valve can be done through the orifice at the beginning and end of the process or, in the case of feeding, by making use of the drain passage by reversing flows as necessary.
If, when the adjustable collar is positioned part way forward along the barrel of the valve and the tip of the valve is flush with the inside wall of the vessel, the collar may be repositioned all the way back on the barrel of the valve and reinserted into the ferrule. Now the secondary o-ring in the valve cap forms the seal with the ferrule and the tip of the valve will protrude beyond the margins of the vessel into the body of the process in a fashion similar to that of in-situ sensors. Since this is the region where the sensors take their readings, taking samples from this area will correlate better with sensor readings. Alternatively there may only be one o-ring groove along the barrel and the valve may always be installed in a protruding fashion or, if the user does not need to remove the device, the barrel may be permanently affixed into the wall of the vessel or conduit in either the flush or protruding fashion, thereby eliminating the need for the o-ring groove and the adjustable collar.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGSThe present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
In the context of these discussions, “ferrule” and “porthole” may be used interchangeably. Furthermore, throughout these discussions a ferrule is discussed as though it had a round cross section with a uniform concentric central throughbore terminating on the process side (front) flush with the interior vessel or conduit wall. Also through out these discussion an example is used where in all parts are aligned in a plane that forms a vertical cross section through the assembly. All of these cases are selected both because they are the simplest arrangement to understand and would probably also be the most likely arrangement to be used. It should be understood, however, that many other related arrangements will become obvious once the design concepts and associated equations presented here are understood. Some examples would include offsetting elements of the system such as passages, modifying shapes such as round or oblong profiles, changing sealing arrangements from o-rings to diaphragms or vice versa. In some cases such as in the case of offsetting passages, these may result in the need to augment or modify certain formulas provided herein to bring them in line with the modified configuration. These changes, however, would be obvious to one knowledgable in the field once they have read and understood the description provided herein and, therefore, should be considered an extension of the art revealed within this description.
It is assumed in this discussion that the design goal is a valve that can be removably fitted into a ferrule. If the designer wishes to install the valve body permanently into the vessel or conduit, the value of the relationships described herein are not lost since they can still be used to achieve the same goal of providing a valve capable of freely draining from a port installed in a configuration that is inclined from a horizontal plane.
It is one of the purposes of this invention to provide means of assuring that when the embodiment of the valve is installed in a ferrule of a vessel or conduit, the lowest point of the valve's orifice 16 will be above the down-directed drain opening 33 (the drain opening being a free-draining exit from the valve located beyond the rear-most bottom margin of the ferrule where a drain would no longer be restricted by being within the geometric confines of the ferrule) and that these two will be connected by a drainage trough within the internal cavity of the valve, trough having a bottom profile from the orifice opening to the opening of the drain opening that continuously declines at an angle greater than the angle of inclination of the axis of the ferrule's internal bore when the valve is installed in the ferrule and that inclines to the sides and to the rear from the drain opening 33. Whether or not free drainage through a flush-mounting (with the internal wall of the vessel or conduit) or penetrating (into the process, beyond the internal wall of the vessel or conduit) valve is achievable when mounted within the fixed geometry of an existing ferrule depends on three characteristics of the ferrule (as installed in the vessel or conduit). These characteristics will be discussed with reference to
Referring specifically to
1) a diameter Df of internal bore 3;
2) an angle Aa of the axis of internal bore 3 measured relative to a horizontal plane, with an inclined bore 3 have a positive angular valve, a declining bore having a negative value and the value of Aa for a horizontal bore being “0”;
3) Lf, the actual length of the bottom margin 56 of ferrule 2, measured from a point (Pr) formed by the bottom rearmost margin 8 of bore 3 forward to the point along the bottom margin 56 where bore 3 opens into the process and is flush with the internal wall of the vessel or conduit.
The length Lf of internal bore 3 can be broken into Lfh, its horizontal component, and Div, its vertical component. Lfh can be calculated:
Lfh=Lf COS (Aa)
When a ferrule is inclined, the bottom rear margin at point Pr rises up like a wall and becomes the high point of a barrier to free drainage from within the ferrule. In order to get beyond that barrier it is necessary to build a drainage trough 18 in the valve that, when installed in the valve 13 will provide an inlet at the process, the orifice 16, whose lower margin 20 forms the beginning of the trough 18 and which passes above or above and to the side of the bottom rear margin 8 of bore 3 down to an outlet 22 beyond the confines of the ferrule, the beginning of drainage trough 20 at the base of orifice 16 being above the outlet of the trough 21 and where the trough constructed within the valve body that continuously descends at an angle greater than the angle of inclination of the axis of the ferrule's internal bore 3 when the valve is installed in the ferrule. A horizontal plane can be imagined to extend forward from point Pr wherein the drain trough, beginning at the lower margin 20 of orifice 16 and passing back, just over and then beyond point Pr, is always above said plane but moving closer to it as the trough descend toward Pr, passing close but still above Pr and then beyond it to a point where it is free of the ferrule and can be drained out of the system. Thus, the start of the drainage trough 20 (which is coincident with the base of the orifice) and the trough all of the way back to a point just beyond point Pr must be above this imagined horizontal plane in order for the valve to freely drain process though inclined bore 3 in ferrule 2 beyond the point Pr.
The vertical component, Div of Lf, is the diametric height lost in order to off set bore inclination. Div can be calculated anywhere along the bottom margin 56 of bore 3 by using the value of Lf at that point and angle of inclination Aa of the internal bore 3. For a flush-mounting design, the full value of Lf would be used and the calculation would be as follows:
Div=Lf SIN (Aa)
In order to actually achieve free drainage, it is necessary to have impart some minimum angle of declination to drainage trough 20 that is in excess of the offset to angle Aa created by the diametric loss Div. The determination of what is a sufficient positive drain angle, Ab, is dependent on the process. The amount of diametric height necessary to create Ab in drainage trough 20 at any point along the bottom margin of bore 3 can be calculated by using the value of Lf at that point and Ab. For a flush mounted valve, the full value of Lf would be used:
Ddv=[(Lf) COS (Aa)][TAN (Ab)]
When a ferrule is installed at an inclined angle, the area where its internal bore intersects with a vertical plane such as the case with a vertical internal wall of a vessel or conduit changes from being circular to being elliptical in cross section (except in some compound angle cases). The major axis of the ellipse that forms the margin of the opening of the ferrule bore into the vessel or conduit we call the vertical diametric axis or the ferrule bore diametric height, Dfv, can be calculated:
Dfv=(Df)/[COS (Aa)]
The point tangent to the upper margin of this opening is (Pt) and will be discussed later.
The diametric height, Dfv, is the vertical height of the internal diameter of the ferrule. It is the composite sum of several diametric components. Its value is important because if it is great enough relative to Lf and to Aa, a valve which will be free draining while mounted in an inclined ferrule can be constructed.
The diametric height Dfv of internal bore 3 of ferrule 2 is composed of:
Dov: Diametric height for orifice construction.
Div: Diametric height lost due to inclination of bore 3 in ferrule 2.
Ddv: Diametric height to assure channel drainage (beyond the horizontal).
Dr1: Diametric space required to make a seal on the upper outside diameter of the valve body 13 with bore 3 of ferrule 2.
Dr2: Diametric space required to make a seal on the lower outside diameter of the valve body 13 with bore 3 of ferrule 2.
Dv1: Diametric space required to form the upper margin of annular wall 17 of the valve body 13 against which a seal is formed when the upper margin of sealing tip 30 engages the upper margin of annular wall 17.
Dv2: Diametric space required to form the lower margin of annular wall 17 of the valve body 13 against which a seal is formed when the lower margin of sealing tip 30 engages the lower margin of annular wall 17.
Dw1: Diametric space required to form the outer wall at the upper margin of the valve body 13.
Dw2: Diametric space required to form the outer wall at the lower margin of the valve body 13 or some minimum wall thickness of the bottom margin of drain trough 18 in order to allow material to flow over point Pr and down to the drain opening beyond.
Ds1: Diametric space required to allow for the interstitial space between the ID of the ferrule 2 and the OD of the valve body 13 along the body's upper margin.
Ds2: Diametric space required to allow for the interstitial space between the ID of the ferrule 2 and the OD of the valve body 13 along the body's lower margin.
In order to be able to construct a free draining valve mounted in ferrule 2:
Dfv>or=[(Dr1+Dr2)+(Dv1+Dv2)+(Dw1+Dw2)+(Ds1+Ds2)+Dov+Div+Ddv]
This equation can be solved for Dov:
Dov<or=Dfv−[(Dr1+Dr2)+(Dv1+Dv2)+(Dw1+Dw2)+(Ds1+Ds2)+Div+Ddv]
The contribution of interstitial space is usually negligible or is difficult to differentiate from the external sealing arrangement elements so it may be folded into Dr1 and Dr2, simplifying the equation to:
Dov<or=Dfv−[(Dr1+Dr2)+(Dv1+Dv2)+(Dwv1+Dw2)+Div+Ddv]
Since wall thicknesses, sealing arrangements, interstitial space and annular seal arrangements are all determined by specific process requirements, manufacturing materials and methods which may be held constant for a range of different ferrule and valve configurations, a constant C may substituted for them and the equation rewritten as:
Dfv>or=(Dov+Div+Ddv+C)
Or:
Dov<or=Dfv−[Div+Ddv+C]
Or:
Ddv<or=Dfv−[Div+Dov+C]
It is important to find the optimal combination of both the orifice side and the drainage angle in order to get the best drainage from the system.
In order to determine if it is possible to build a valve that will drain from positions within the process or from positions within the ferrule, an effective internal bore length, Lfe can be substituted into the equations for Lf. Lfe is the measured length along the bottom margin 56 of bore 3 from Pr to the point that would be coaxial with a vertical axis passing through the point 20 selected for the bottom margin of the opening of the orifice 16 into drainage trough 18. A penetrating valve design has the effect of lengthening the ferrule bore length. A longer inclined ferrule bore length results in larger values of Div and Ddv in order to maintain the steady drop over a longer effective ferrule length. This, in turn, results in less residual diametric height for the sampling orifice as well as other structural elements of the valve. If the diameter Df of bore 3 is too small, the angle Aa too steep or the length of penetration too great, all of the diametric height available in a particular ferrule installation may not be enough to compensate for the values of Div and Ddv as well as other valve diametric components. In this case it would not be possible to build a free draining valve.
For penetrating or flush-mounting valve designs, when a horizontal plane through Pr is also coplanar with Pt or when this plane passes above Pt, no free draining valve may be constructed. It is always necessary with penetrating or flush mounting designs that at least the lower margin of drainage trough 18 pass under point Pt with sufficient vertical space between the two such that the construction of the valve structural components necessary above the trough can be accomplished and yet still allow some vertical height so that flow can be achieved down the trough, past Pt.
For a system (valve and ferrule) which includes a valve with an orifice formed within the confines of the ferrule, the position of Pt is not relevant since flow can move the ferrule to and through the orifice (assuming the level of fluid in the vessel or conduit is also above the level of the orifice). In the situations where the orifice is within the ferrule bore, the new Pt is the point that is the upper margin of the ferrule bore located in a vertical plane that also passes through the lower margin of orifice 16. In fact, Pt can always be defined as the point that is the upper margin of the ferrule bore located in a vertical plane that also passes through the lower margin of orifice 16 and, in the construction of the valve, it is merely necessary that the trough originating at the base of orifice 16 descend at some angle while installed in the ferrule but still pass above point Pr or above and to the side of Pr on its.
In some large vessels equipped with relatively long steeply angled small diameter ferrules, it is not even possible to construct flush-mounting valve arrangements. In these cases the best that can be accomplished is to draw the position of the orifice back up into the ferrule internal bore to appoint where there is sufficient diametric height to accommodate all of the necessary valve structural elements, including a sufficiently large orifice and a steep enough slope for the drainage trough. This situation is less than optimal since positioning the orifice up inside a ferrule places it in a “quiet” zone which will tent to stray in character from the more highly mixed body proper of the process.
Referring in detail to
The vessel 53 has a ferrule 1 on the side thereof. Conventional ferrules 1 have a 25 mm intelnal diameter, for example. A main body 10 of the instant apparatus A has been designed to have an outer diameter generally equal to or slightly less than a standard ferrule diameter. While this 25 mm dimension has been given, it should be recognized that it is merely necessary to have the outer diameter of the body 10 of the instant apparatus A slightly less than the inner diameter of any existing size ferrule. The instant apparatus A of any size can therefore be easily retrofit to existing vessels or conduits with ports of any size. Of course, the instant apparatus can also be assembled to newly manufactured vessels or conduits.
The necessary equipment for either charging a sample to the vessel or conduit 53 or removing a sample from the vessel or conduit 53 is provided through body 10 of the instant apparatus. Therefore, it is not necessary to alter existing equipment when using the instant invention. This arrangement provides for easy retrofit with standard designed vessels or conduits.
Turning now to
The main sample subassembly 2 comprises a body 10 with an internal cavity 3. This cavity 3 includes a sample cavity 11 and a central bore 13 which will be discussed in more detail below.
A supply means 50 is provided for supplying at least one of steam, air and wash medium to the apparatus. This supply means 50 helps maintain an aseptic environment. In some situations, steam alone is sufficient for cleansing the system. In other uses, it is necessary to use pure dry air or a wash medium. Moreover, any combination of these materials can be used. The wash medium can include detergents, alcohol, an alkaline rinse, acid rinse or other wash material. It should be evident that many different arrangements can be used for cleaning and/or sterilizing the instant invention.
The supply means 50 of the instant invention includes a steam feed valve block 5, a pure dry air valve block 6 and a wash medium valve block 7. The steam feed valve block 5 includes a steam source 66 connected to a diaphragm pneumatic valve 67. Also connected to this valve 67 through an electromagnetic valve 69 is a pressurized air source 68. It should be noted that any suitable type of automatic or manual valves 67 and 69 can be used in the instant invention or that these two valves can be combined into a single unit.
The pressurized pure dry air valve block 6 includes a pure dry air source 70. This pressurized pure dry air source 70 is connected to diaphragm pneumatic valve 71. Also connected to this valve 71 through an electromagnetic valve 72 is a source of pressurized air 73. Similarly to valves 67 and 69, it should be understood that any type of valve can be used for the valves 71, 72. Also, a single unit could replace these two valves 71, 72.
The wash medium valve block 7 includes a supply of wash medium 74. As noted above, this wash medium can be a detergent wash, an alkaline wash, an acid wash, an alcohol wash or any suitable cleansing arrangement. The supply for wash medium 74 is connected to a diaphragm pneumatic valve 75. Also connected to this valve 75 through an electromagnetic valve 76 is a source of pressurized air 77. Again, similarly to valve 67, 69, 71 and 72, any suitable valve or a single unit can be used for these valves 75 and 76.
The electromagnetic valves 69, 72 and 76 are indicated as being connected to the control means 4. It should be noted that the diaphragm pneumatic valves 67, 71 and 75 are also connected to the control means 4. It is merely necessary for the control means 4 to control supply of steam, pure dry air and/or wash medium to the inlet passage 12. Each of these mediums is connected to the inlet passage 12 through the respective valves 67, 71 and 75. Moreover, while three valve blocks 5, 6 and 7 are shown, any of these can be omitted or additional valve blocks could be used as needed. Also, valves 69, 72 and 76 can be combined into a single valve.
The inlet passage 12 is shown as being continuous from the main sample subassembly 2 to the supply means 50. As noted above, this main sample subassembly can be machined from a single block. Appropriate tubing, piping or other connectors can be used to connect the inlet passage 12 bored within the main sample subassembly 2 to the supply means 50. A tri-clamp connection 15 connects this tubing or piping to the inlet passage within the main sample subassembly. It should be noted that it is usually possible to perform all of the functions normally expected of the above described inlet port through either the sampling orifice (33, described later) in combination with the drain passage 14. For this reason in many cases it may be possible to eliminate the inlet port.
A drain passage 14 is also provided in the instant invention. This drain passage can be bored within the main sample subassembly 2 or can be piping connected to a downstream means for collecting a sample 51 and means for collecting drain 52. These means 51 and 52 will be discussed in more detail below. Similarly to the connection for the inlet passage at 15, the drain passage 14 has connection 16. Rather than using a tri-clamp at the connections 15 and 16, any suitable connection arrangement can be made.
Both the inlet passage 12 and drain passage 14 are connected to the interior sample cavity 11 of body 10. This body 10 not only includes sample cavity 11 but the central bore 13 which together form the above-noted internal cavity 3.
Internal Portion of Valve
From the rear of sample valve 2, the valve operating rod 22 extends forward through the central bore 123A of the a spring backstop 118A which will be discussed later and into the central bore 13 of body 10 as seen in
Extending between seat 86A of the spring backstop 118A the valve operating rod detent 23 is a spring 27. This spring 27, shown in
Turning to
In
Once assembled, the diaphragm/rod combination can be slipped forward through the back of body 10 until front base seal 317 engages the real annular diaphragm mating face 319. Diaphragm backstop 300 is slipped over the rear portion of rod 22 until its backstop forward face 302 and diaphragm detent 301 engage back base seal 318 and annular slip 313 of diaphragm 49A. Next, valve operating rod detent 23 may be slipped onto the rod and snapped into the groove on rod 22. Next, spring 27 can be slipped over rod 22 until its forward end engages the rear wall of spring detent 23. Spring sleeve 310 can be slipped around spring 27 and into the rear portion of central bore 13 of internal cavity 3 of body 10 until the forward face 312 engages backstop rear face 305. Lastly, spring backstop 118A can be slipped over the rear portion of rod 22 until its external threads engage the internal threads of body 10. By applying a hex wrench to rear hex 28A and tightening it into body 10, its forward face (spring seat 86A) will urge spring sleeve forward against the backstop rear face 305 which in turn will press up against the back base seal 318 and annular lip 313, causing front base seal 317 of diaphragm 49 to seal against the annular sealing surface of body 10. The tightening of spring backstop 118A also causes spring 27 to be compressed against the spring detent on rod 22, thereby urging the shaft's tip and the diaphragm sealing tip 32 against the annular sealing surface about orifice 33.
When valve operating rod 22 is retracted, blunt sealing tip 32 will be withdrawn from orifice 33, allowing material to flow into sample cavity 11 and down and out drain 14. When the actuator is inactivated (whether a manual or automated device), the compressed spring 27 acting against detent 23 will urge blunt sealing tip 32 forward until it again the sealing surface about orifice 33. The blunt sealing tip 32 of diaphragm 49A tends to form a good seal, helping to minimize deadspace at orifice 33. Of course this blunt sealing tip can be configured in many ways. It is merely necessary that an appropriate seal be formed with the orifice.
Spring detent 23A consists actually of a retainer ring fitted into a retainer ring slot 23B along rod 22. A washer can be added to form a more uniform mating surface with the spring.
Spring detent 23 can, of course, be an integral part of operating rod 22 but if operating rod 22 is machined out of a solid bar stock rod, making the spring detent an integral part would simply mean more work since it would require starting with thicker bar stock. In some cases, however, making this as one piece may be advantageous.
Alignment of the valve internal components can be seen. To the rear, alignment for the valve operating rod is provided by the bearing surfaces of central bore 123 in spring backstop 118A and forward, alignment is provided by the bearing surfaces about o-ring grove 308 of diaphragm backstop 300.
While a diaphragm with a large sealing tip, a reduced diameter shank and large base is shown, it could be constructed in many other ways. It is only important that there be associated with it an effective sealing tip and a shaft and base portions that allows the tip to be reciprocally opened and closed without exposing the process or sampled material to the mechanical components of the valve.
The use of a diaphragm 49 with conical flexing base 314 and blind bulb end 31A has several benefits. First, all of the moving mechanical parts (such as the valve operating rod 22A and other components associated with central bore 13) are removed from the sample in sample cavity 11. The diaphragm 49A with its conical flexing base 314 are made from a biocompatible rubber, plastic or metal material with thermal and chemical tolerant properties. Furthermore, these components are flexible and have a wide range of motion. This great range of motion allows the apparatus to achieve a flush (or penetrating) mounting condition on a vessel or conduit, even when retrofit to an existing design. Further, this design allows the blunt sealing tip 32 to be withdrawn from the sampling orifice 33 over a great distance. This facet allows the apparatus to provide minimal sample size bias for samples with particles up to at least six mm size in this particular configuration.
In
A discussion of the connection of the actuators and their connection to the operating rod will be discussed below.
Blunt sealing tip 32 will assuredly seal orifice 33 and not deform and protrude through the orifice 33, because the tip 32 is backed by a metal cap which gives solid support. Also, this cap 21 will prevent tip 32 from sticking to the area around the orifice 33 when the operating rod 22 is retracted.
Endcap
The orifice 33 is provided in the body 10 as seen in
In
By appropriate selection of materials, body 10 can not only exhibit insulating thermal properties but also electrical as well. Key among the benefits of these insulating properties is the ability to protrude the sampling orifice into the body of a process that is heat labile. This allows the placement of a heat resterilizable sampling tip to be placed in a heat labile process in an area adjacent to where in-situ measurements are being taken, significantly increasing the value of the sampled material and its relevance to the development effective process monitoring and control.
To improve drainage from orifice 33 down and out of the sample cavity 11, the inner walls of cap 44 in the previous embodiment were inclined as could be seen in
As will be discussed later, the forward end of the valve, including tip 32, can be extended beyond the inner wall 56, where a stagnation layer forms to a greater or lesser degree, into the vessel or conduit interior. By moving the sampling orifice 33 into the body of the fluid, interference from stagnating material along the margins is reduced, increasing the level of quality of representation that the sample has of the bulk of the process. The character of the sample will also correlate better with measurements taken from sensors since their sensing elements are also positioned away from the wall in the bulk of the process. In many cases it is not sufficient to have only the ability, to withdrawal a sample from deep within a tank, it is also important that the process be thermal or electrically protected. The most recent embodiment of the valve may include an insulated body in order to minimize any adverse effects that might occur as a result of any thermal or electrical treatments that may be done to the valve interior between sampling events. These insulating properties will significantly improve the ability to correlate in-situ sensor data with the actual conditions at those points within the body of process by virtue of the current invention being capable of being installed with its sampling orifice adjacent to the sensors without adversely affecting the process.
Mounting to a Slanted Wall
In the arrangement shown in
Coupler
In
Around body 10 and extending for a distance forward from front side 91 are a series of evenly spaced, uniform circumferential positioning grooves 104. Movably positioned in front of front wall 91 of body 10 and around body 10 is a short cylindrical positioning collar 175. Positioning collar 175 has a retainer flange 92 flush with its front wall 91a. Extending through flange 92 in radial fashion are a set of threaded through holes with set screws 178. These are evenly spaced around its circumference. Leading away to the rear from the flange is a smaller diameter shoulder 176. Positioning collar 175 has a uniform cylindrical inside surface which allows it to move smoothly back and forth on body 10 when set screws 178 have been sufficiently loosened. Coupling nut 105, consisting of an internally threaded cylindrical section 106 ending in a short inner annular lip 177, is positioned around body 10, behind positioning collar 175. This inner annular lip is of a smaller diameter then the outer diameter of flange 92 but greater than that of shoulder 176. Thus, coupling nut 105 can be slipped forward over shoulder 176 so that the forward wall of its inner annular lip 177 can engage the rear wall of flange 92 but preventing it from ever passing around flange 92. The diameter of its inner threads are only slightly greater then the outside diameter of flange 92. The length of set screws 178 in positioning collar 175 have been selected so that their heads will be flush with the outer surface of flange 92 only when they are threaded firmly down into one of the positioning grooves 104 on body 10. The forward threaded portion 106 of coupling nut 105, therefore, cannot be slipped forward over set screws 178 and be made to engage with the external threads 107 of ferrule 1 until set screws 178 are all tightened down firmly onto body 10. Coupling nut 105 can then be tightened onto threads 107 of ferrule 1 until front wall 91a of positioning collar 175 engages the rear wall of ferrule 1. With coupling nut 105 tightly fixed to ferrule 1 and covering set screws 178 which are tightened into a groove 104, and because inner annular lip 177 of coupling nut 105 can not slip by retainer flange 92, main sample subassembly 2 is firmly but removably fixed to ferrule 1. Any other subassemblies attached to subassembly 2 will, therefore, also be firmly but removable attached to ferrule 1.
With coupling nut 105 pulled back and set screws 178 sufficiently loosened, position collar 175 can be repositioned along body 10, allowing main sample subassembly 2 to be adjusted to fit different length ferrules or, in a given ferrule, to change its interface with the process from one of flush mounting to one of penetration.
Another means, illustrated in
A coupling nut 105, consisting of a hollow cylindrical section with a forward internally threaded cylindrical section 106 having an inner annular lip 177 on the rear side thereof, can slide freely around the rear portion of a positioning collar 175. The positioning collar 175 consists of a long, relatively thin cylindrical sleeve or shoulder 176 extending to the rear and with a set of screw through-holes 186 located near but not at its posterior margin. Forward, the positioning collar 175 has a short, double flanged cylindrical section, the outer radiating flange is retainer flange 92 while the inner radiating flange is positioning flange 167 and the forward wall of both of these being the forward wall 91a of positioning collar 175. There are a set of longitudinal through holes 187 bored longitudinally through forward wall 91a and flange 167 adjacent to its inner annular margin. These holes 187 are fitted with countersunk coupler positioning screws 180. These coupler positioning screws 180 are held captive in flange 167 of positioning collar 175 from behind by retainer rings 158 riding in grooves 188 in the screw shafts and from the front by the screw heads which are counter sunk in the forward wall 91a of positioning collar 175.
The coupling nut 105 can be slipped onto the positioning collar 175 from behind and held from slipping off the front by the retainer flange 92. With cylindrical retainer sleeve 156 already in place on shoulder 181 of body 10, the positioning collar 175 with the coupling nut 105 already around it can be slipped around body 10 from the front. Positioning screws 180 can be threaded into the longitudinal holes 189 in the front wall 91 of body 10. When these screws 180 are threaded in holes 189 far enough, screw holes 186 of the shoulder 176 will align with the threaded holes 157 in the cylindrical retainer sleeve 156. At that point, a second set of screws 185 are fitted through holes 186 in shoulder 176 and tightened radially into threaded holes 157 in cylindrical sleeve 156. Once these screws 185 are tightened, coupling nut 105 is captured behind retainer flange 92 of positioning collar 175 on body 10. Furthermore, the position of flange 92 and forward wall 91a which engages the back wall of ferrule 1 during coupling, can be adjusted along body 10 relative to the position of orifice 33 simply by threading screws 180 in or out of holes 189 in body 10. Thus, sampling subassembly 2 can be custom fit to vessels and conduits with a variety of ferrule lengths as well as providing a means to couple the apparatus in a penetrating fashion in a ferrule of given length.
Because the forward advance of the coupling collar 175 is stopped by the engagement of the forward wall of cylindrical retainer sleeve 156 with the rear wall of retainer ring 142 before the longitudinal screws can be threaded out of their respective holes, a user cannot inadvertently disengaged the coupler 57 from the valve, a potentially dangerous event should the vessel then be pressurized.
O-rings and grooves to receive the o-rings can be added along the inside circumferential surfaces of cylindrical retainer sleeve 156 and positioning flange 167 to inhibit this region from collecting dirt.
A third method of removably attaching the main sample subassembly 2 is shown in
Of course, there are other methods to removable attach the main sample subassembly 2 and these means can be modified in various ways. An example would be the elimination of the grooves 104 on body 10. Though they provide a certain added safety margin, grooves 104 are not essential for the coupling means to work properly or effectively.
Back End Plate
Engaged with the rear wall 119 of body 10 is the front wall 117 of back end plate 118 as seen in
Once the intent of plate 118 and its seals have been described, it should be clear to anyone familiar with the art that many other sealing arrangements could be used so long as the sealing purpose is achieved.
Assurance of alignment of back end plate 118 with components of the main valve body 10 and, in particular, valve operating rod 22, is achieved by mating of opposing planar surfaces of front wall 117 of back end plate 118 with rear wall 119 of body 10 as well as the close fit of the alignment lip created by the outside circumferential wall 128 of forward protruding portion of annular section 122 mating with an opposing circumferential wall 129 of central bore 13 adjacent to its intersection with the rear wall 119 of body 10. Of course, it should be understood that proper alignment could be achieved in a variety of other ways. These could include: a series of alignment pins or screws in back end plate mating with an opposing set of alignment holes in body 10 (or vice versa); threading outside circumferential wall 128 to mate with the threaded section of central bore 13 behind rear valve operating nut 28; and other arrangements of opposing alignment surfaces or walls machined to relatively fine tolerances.
Back end plate 118 may be secured against rear wall 119 of body 10 directly using screws, clamping or other suitable means or indirectly by being sandwiched between the rear wall 119 of body 10 and the forward wall 168 of an automated actuator housing 41 (shown in
Coupling Shafts
In order to allow for easy, fast connection of the reciprocating shafts of each of these subassemblies to one another, a means for coupling 200 has been incorporated into the design. As illustrated in
The connector cap 169 has a greater diameter then the connector shaft 170 as illustrated in
Although these slots can be through slots, the slots of the interlocking connection shown in
Once the two shafts are mated, the two subassemblies can be pushed together and secured. The interlocking connection between the two shafts will slide into the central bore of the rear subassembly where they cannot become disengaged until the subassemblies are again taken apart. This arrangement provides a safe, sure and effective connection that, once assembled, cannot inadvertently become disengaged as may be the case with some other connections.
The rear end of the automated actuator piston 39 terminates in a connector cap 169a and connector shaft 170a just like that of rod 22. This allows the user the freedom to attach the automated actuator alone, the manual trigger actuator alone or the automated actuator with the trigger actuator attached behind that, providing an automated system with manual override capabilities. Using this design, switching actuator combinations can be made quickly, easily and without modification of the equipment or interference with the valve's on-line process operation.
Actuator Attachment
As indicated above, manual and automated actuators can be used with sample valve subassembly 2 to operate the valve. The benefits of using automated operators include higher levels of reproducibility both qualitatively and quantitatively over the current manually operated equipment. There is also the benefit of attendant-free operation. But if there is a power loss, a mechanical problem or an unanticipated sampling requirement, automated systems can be clumsy or altogether non-functional. In this case, manual systems are much more dependable, less expensive and do not require the support systems, such as pressurized air, electricity, etc. Then, again, manual systems are not normally as qualitatively or quantitatively consistent and require an attendant to take a sample. Because of the variety of situations that exist and because those situations change with frequency, this system was developed to offer the operator any or all operational options without having to shut down the process to remove and modify the actuators on the valve.
The rear wall 130 of back end plate 118 and the rear wall of the automated actuator 179 are both equipped with a means for aligning and attachment to opposing housings as can be seen in
The means for attachment of the actuators can be as follows. The front wall 131 of the manual trigger actuator housing 109 can mate with either the back wall 130 of the back end plate 118 or the back wall 179 of the automated actuator housing 41. The front wall 178 of the automated actuator housing 41 is essentially the same as the front wall 131 of that of the manual trigger actuator housing 109, the difference being only that the lower portion of front plate wall 132 has been removed in order to allow trigger lever 111 to start further forward so that it can have a longer stroke. Both of these walls mate with the back wall 130 of the back end plate 118.
Of course, the threaded holes could be eliminated from body 10 and, instead be place in back end plate 118. Back end plate 118, itself, can be attached to body 10 in a variety of ways, including clamps, threads, etc. Here, back end plate 118 is attached to body 10 by a separate set screws 196 in back end plate 118 with a set of matching threaded holes 197 in body 10. Of course, other means by which the opposing faces of these subassemblies are secured to each other could be clamp flanges, bayonet or any other appropriate means.
Manual Trigger Mechanism
As described above, the manual actuator subassembly 108 can either be attached directly to the valve at the back end plate 118 or indirectly through the automated actuator housing 41. Similarly, the rear valve operating rod 113 which is the reciprocating member of the manual actuator subassembly, can be connected directly or indirectly to the valve operating rod 22 as described above. Unlike other manual actuators, however, this manual actuator makes use of trigger action for quicker, more precise control of sample volume and better, more reliable sample quality. The manual trigger actuation mechanism primarily comprises a retracting trigger lever which engages a transverse pin in the rear valve operating rod. As the rear valve rod is retracted, it pulls the forward valve rod attached to the sealing tip back away from the valve orifice, opening the valve.
In its simplest form shown in
A central longitudinal bore 135 through the housing has an axis coinciding with that of valve operating rod 22. Reciprocating within bore 135 is rear valve operating rod 113 which is attached to valve operating rod 22 either directly or indirectly through actuating piston 39 of the automatic operator by the interlocking means 200 described above. Between the two side plates 109a and 109b is the trigger lever cavity 137. Rear valve operating rod 113 extends from inside the central bore 135 in front plate 132, through cavity 137 and out the other side through the rear wall 138 of trigger lever cavity 137. Although central bore 135 extends through rear plate 109c, the rear wall of rear valve operating rod 113 can be shortened so as only to come to a point flush with the back wall of plate 109c when rod 22 and sealing tip 32 are fully retracted. Thus, when the valve is opened, because the end of the rear valve operating rod 113 is always enclosed, it cannot be interfered with or cause injury to anyone who might be near it when it is actuated.
If the return spring 27 used to keep the valve in a fail close condition is not too strong, a trigger lever 111a can be attached directly to the bottom of rear valve operating rod 113 using screws. By placing the palm of the hand on the palm rest and pulling back on the lever with a finger, sealing tip 32 can be retracted from orifice 33, thereby opening the valve. When the lever is released, return spring 27 will automatically close the valve. This design is simple, effective and relatively low cost to manufacture but it suffers from the following flaws.
First, if the return spring is strong, retracting and holding it with one or even several fingers for a period may be hard. Second, because the handle is attached directly to the shaft, if something gets in its way and nobody is around to clear it such as may be the case when using automated operation, the valve may incompletely open or close or not move at all. Also, if someone is standing in the way of the trigger lever when the automated actuator reciprocates the valve, they could be hit and injured by it. Lastly, the lever could be accidentally hit and the valve inadvertently opened. If additional cost is not as important as resolving these problems, then some or all of the following changes can be made to reduce or eliminate these weaknesses.
A more versatile alternative than direct attachment of the trigger lever to the valve operating mechanism is to provide a means by which to adjust the leverage provided by the trigger lever. This would make it easier to use without effecting the valve's sealing characteristics. This can be accomplished effectively if the trigger lever is not coupled directly onto the rear valve operating rod 113.
Positioning knob 115 is fixed in housing cover 112 by the placement of the knob retainer ring 116 in an annular slot 153 on threaded shaft 152 on a side of housing cover 112 opposite positioning knob 115. The point of engagement of transverse pin 155 in rear valve operating rod 113 along the length of trigger lever 111 (and, thus, the leverage) can be set by changing the position of transverse cam 114 along leverage slot 150. The position of transverse cam 114 along leverage slot 150 is, in turn, determined by its position along the threads of shaft 152. Consequently, the operator can adjust the leverage of the trigger mechanism 108 simply by turning positioning knob 115.
As discussed earlier, rear valve operating rod 113 is attached to automated actuator 39 or valve rod 22 by the interlocking means 200. Just to the rear of slots 171a and 172a of the interlocking means 200 on rear valve operating rod 113, the sides of the cylindrical rod are milled so as to have two parallel flat opposing external walls 147. The distance between the two arms 146 of trigger lever 111 is slightly more than the thickness between the parallel walls 147 of rear valve operating rod 111. Once installed, rear valve operating rod 113 can slide freely back and forth between arms 146 of trigger lever 111 but cannot rotate because of the engagement of the flat surfaced lateral walls of rear valve operating rod 113 with the opposing flat surfaced arms 146 of trigger lever 111.
Although a non-threaded means of connection was used between rod 113 and rod 22 or piston 39, elimination of rotational motion in this design would permit threaded connections to be used. But this is not the most important aspect of this design. Because the point of engagement of the trigger lever 111 with transverse pin 155 is from the rear and because rear valve operating rod 113 can slide independently backward between trigger lever arms 146, the valve can be actuated automatically without moving the trigger lever 111. Thus, injuries can be avoided during automated operation. Furthermore, transverse pin 155 will always be correctly positioned to engage the trigger lever arms 146 when manual actuation is required. The rear margin 199 of arms 146 of trigger lever 111 where they engage transverse pin 155 have been rounded so as to reduce torque on rear valve operating rod 113 during retraction.
Trigger lever 111 is kept in the forward position and is not carried back with the momentum of an automated retraction of the rear valve operator rod 113 due to the application of forward spring tension acting on the lever arms 146. One end of a small utility return spring 201 is attached by a threaded spring anchor 202 into the inside wall of housing cover 112 while the other end is attached to the two lever arms 146 through two small holes positioned above rear valve rod 113.
To check against inadvertent actuation of the sample valve, a safety catch is incorporated into one side wall 109a of the trigger housing 109. Here, a three-position rocker switch 203 is used. When switching into the “locked” safe position, the right half 204 of the rocker switch is depressed all the way in. This makes the back portion 205 of the rocker wedge in behind the transverse pin 155, locking pin 155 from moving back. When a sample is to be taken, the operator can press on the left half 206 of rocker switch 203 to move it to the neutral unlocked position, freeing up transverse pin 155. Since rocker switch 203 is spring loaded, it will tend to stay in this position until switched again.
If the operator wishes, the valve can also be locked in the “opened” position. This can be accomplished simply by, first, pulling trigger 111 all the way back to fully retract the valve operating mechanism and fully open the valve. At this point, transverse pin 155 is behind the back portion 211 of the left half 206 of rocker switch 203. By depressing the left half of switch 203 all the way to the third locking position and releasing the trigger lever 111, the back portion 211 of the left half 206 of switch 203 will engage transverse pin 155 and hold it there as the return spring returns the valve operating mechanism forward. The rocker switch can also be color coded on the sides so that its exposed surfaces will quick indicate its status.
If adjustments to the spring tension acting on the sealing tip 32 or limitations on the stroke of the valve are desired, a secondary spring return can be incorporated by boring out the trigger housing central bore 135 behind rear wall 138 of trigger cavity 137 and threading it to make backstop bore 145. A retainer ring groove 207 is cut in rear valve operating rod 113 and retainer ring 208 added. A washer 209 is add between retainer ring 208 and secondary return spring 27a which is fitted over the back end of rear valve operating rod 113. Tension is maintained and adjusted by a threaded back stop positioner 140. Back stop positioner 140 comprises a hollow cylinder 182 with a threaded outside diameter which is attached to a cylindrical positioner knob 184 by a annular spacer 183. Parts 183 and 182 have a through bore 141 large enough to accept the diameter of the spring around rear valve operating rod 113. Knob 184 does not have a through bore but to permit independent adjustment of the back stop and spring tension, it can be bored and threaded. A threaded bolt can be adjustable threaded into it to set the back stop position. Otherwise, using backstop 140 to change the backstop position will, at the same time, change the spring tension acting on sealing tip 32 unless secondary return spring 27a is not included in the assembly. By tightening back stop 140 all the way in, it can also be used as a safety lock to prevent the seal formed between the sealing tip 32 and orifice 33 with the process from being broken unintentionally by immobilizing the valve operating rod mechanism 159 in the sealing position.
Alternative Manual Techniques
There are several other methods by which the valve rod may be actuated directly or indirectly.
1) DOUBLE PARALLEL SHAFT: An alternative to the above is to attach a second (alignment) shaft to the rear wall of the valve body 10 with a longitudinal axis parallel but not coinciding with that of valve operating rod 22. This alignment shaft extends further back so that when a finger catch or trigger lever having a rectangular upper portion with two horizontal bore holes is fitted onto the two parallel shafts and retracted to a point that, if coupled to the valve operating rod, would represent a fully open state, the end of the alignment shaft would still extend back to the rear of the rear wall of the rectangular portion.
A retainer ring or other stop is attached toward but not at the end of the valve operating rod 22. A low power secondary return spring to serve as a trigger lever return is slid onto the alignment shaft and kept in place from the rear by the attachment of a palm rest to the end of the alignment shaft. When the trigger handle is retracted, the retainer ring near the end of valve operating rod 22 will engage the rear wall of the rectangular portion of the trigger lever about the bore hole through which it protrudes and retract valve operating rod 22, opening the valve.
An advantage of this design over the one discussed earlier is that the alignment shaft minimizes torque on valve operating rod 22 and its extension. Also, the secondary spring about the alignment shaft assures that the added friction created by the addition of the trigger lever will not affect sealing performance of the valve. Further, an automatic operator can be added to the valve and operated safely, the only exposed part moving being the smooth valve rod, the reciprocating end of which can always be housed in a receiving cylinder in the palm rest. A disadvantage is that there is no means for adjusting the power required to overcome the valve return spring.
2) CABLE ACTION: Still another alternative would be to have the trigger lever rotate about a cam in a housing extending out from the rear wall of the valve body and connecting to the palm rest in the rear, the housing and the connection to the valve being similar to that described above. With one end of a cable, flexible band or other means attached to the top of the trigger lever on the opposite side of the cam from the finger catch, the cable would pass back into the palm rest, around a pulley or other similarly functioning element in the palm rest and pass forward along an axis coinciding with that of the valve operating rod 22. It would attach to the rear of valve operating rod 22 at pin. A rotational trigger lever return spring would tend to keep the trigger lever in the returned position. If the position of the cam can be repositioned along the length of the trigger lever so that the lever arm lengths can be changed, this design has all the advantages of the above as well as leverage adjustment. Various other arrangements can be arranged using gears assemblies, including rack and pinion designs. These can, however, become complex and expensive, with several moving parts.
Pneumatic Control
The pneumatic automated actuator 40, illustrated in
Probe and Sensor
Returning to
The means for detecting 4a and probe 20 can provide for independent verification of the various aspects of the system's operation. By comparing a profile of a sampling system temperature or pressure when the system is operating correctly with profiles when various components of the system fail, a determination can be made by the means for detecting 4a of a system failure (abnormal operation). Moreover, a determination can be made by the system as to the severity of the failure and whether to abort further sampling cycles as well as to sound an alarm. The temperature or pressure profile is captured from the probe 20 and fed to the means for detecting 4a. Accordingly, if the diaphragm 49, for example, were to rupture, the probe 20 could determine this condition. Moreover, if there was blockage in the inlet passage 12, this condition could be detected. The means for detecting 4a with the control means 4 can initiate appropriate action. This probe 20 can also detect if an adequate steam temperature has been reached during the sterilization cycle.
Sample Collection
Returning to
The drain valve block 9 includes a diaphragm pneumatic valve 97 connected to a disposal means 98. Also connected to the diaphragm pneumatic valve 97 is an electromagnetic valve 99 and a source 100 of pressurized air. Similarly to the valves 67, 71 and 75, the diaphragm pneumatic valves 93 and 97 can be replaced by any known valves. Likewise, the valves 95 and 99 could also be replaced by other valves or the valves 93 and 95 and the valves 97 and 99 could be combined into a single unit. The electromagnetic valves 95 and 99 are operatively connected to the control means 4 as indicated in
Feed/Drain Lines
Turning now to
Furthermore, the surfaces facing into the sample cavity 11, when endcap 44 is in place, generally are angled in a declining fashion such that flow is down and out of sampling cavity 11 through declining drain passage 14. Thus, gravity alone will insure complete drainage of any material entering the valve through either inlet passage 12 or orifice 33 down and out through drain passage 14. Inset within the base of the sample cavity, leading away from the lower rear point of sealing of o-ring 17 in groove 36 of cap 44 with body 10, is a drain collection trough 42 declining to and through opening 48 from internal cavity 11 into drain passage 14. Drain collection trough 42 can actually be an opened extension of drain bore 43 up and into a side of the sample cavity 11, rather than terminating flush with the rear wall at opening 48 into sample cavity 11 as can be seen in
In
As can be seen in
Due to the positioning of the inlet passage 12 above the drain passage 14, the position of declining drain collection trough 42 leading through opening 48 to become drain passage 14 as well as the smooth, flush transition between the drain passage and the bottom wall of drain collection trough 42 all with respect to sample cavity 11, a means 45 for preventing accumulation of material in cavity 11 is formed. This means will enable free flow of the sample from the sample cavity 11 to the drain passage 14. Pooling of the sample will be avoided. Therefore, possible contamination of subsequent samples is avoided.
Also, drain passage 14 has an internal diameter of generally 6 mm. This is generally larger than the biggest sample particle drawn from vessel 53. In that way, clogging of the drain passage 14 is avoided. While maximum sample particle size is one variable to be considered when designing a valve for retrofit onto a vessel, other variables defining the configuration of the existing ferrule that will receive the valve are also important. Below a mathematical relationship which includes these variables will be discussed, showing how the variables may affect each other and how this can be used to define critical parameters for a free-draining valve.
As seen in
As seen in
Angles of Installation
In
As shown in
In the upwardly inclined ferrule 1 of
Determing whether or not a valve can be retrofitted to an existing port can be done using the relationships described earlier. The latest embodiment described above provides a means by which material may be removed through an upward sloping ferrule, contrary to intuition. For example, a ferrule with a upward slope of 15 degrees, a length of 1.0″ and a diameter of 1.0″ can be fitted with a valve with an orifice having at least 0.25″ diameter with a sealing face about the orifice of over 0.4″ in diameter and with a internal drainage trough which has a declining slope of at least 16 degrees. When installed in the ferrule, this valve has a net declination to its internal profile. This, in conjunction with the smooth, declining orientation of the internal cavity sides and rear wall leading back to seal face 320 combine to make this an effective fully drainable valve even in this orientation.
In the present application, longitudinal axis 59 of inlet passage 12 may decline by as much as 90 degrees, but at least by an amount greater than the amount of inclination of the ferrule. Similarly, the longitudinal axis 58 for drain passage 14 may decline by as much as 90 degrees, but at least by an amount greater than the amount of inclination of the ferrule. While flow related problems are less of a concern with horizontal and declining ferrule installations, it is potentially a much more serious problem with inclined ferrules. The trend in the industry is toward inclined ferrules, particularly those at 15 degree angles of inclination. With the incorporation of end cap 44 into body 10, eliminating the junction between these two and the creation of a drain trough 42 formed with the bottom of sample cavity 11 with all surfaces draining down to and exiting through drain opening 14, the potential for sample and process contamination due to sample hold up and carry over in crevices and pooling on non-draining surfaces has been minimized. Unlike other designs, this is not dependent on flushing material out through multiple washes or high pressure flows. This most recent embodiment has its surfaces optimized to promote free and full drainage.
Process Control
Process control for the instant invention is carried out under the direction of the control means 4. As noted above, this control means 4 can be a programmable logic controller, computer operated controller or any other suitable control means. The control means 4 permits the appropriate sequencing of the various valves of the instant invention. Collectively, the system sequences and times the opening/closing of each valve as well as the sampling device but will allow an operator to program the length of time each valve will remain open. This provides a means by which the process control system can be adapted and incorporated into a variety of different process applications.
Different sized valves, different materials of construction, different process flow temperatures and flow rates different cleaning or chemical agents (steam, air, wash medium, etc.) and other process materials can influence the proper timing of the various facets of operation (sampling, cleaning, sterilizing, resampling, etc.). A single cycle sequence of the basic components of the system of the instant invention will now be discussed.
The control means 4 controls the functioning of the main sample subassembly 2 in tandem with the five peripheral process flow control valves 5, 6, 7, 8 and 9. The control sequencing is laid out in
The pure steam feed block 5, for example, will control the flow of steam to sterilize the system. Likewise, the pure air feed block 6 will control the flow of pure air through the system for two purposes. First, this air will be blown through the inlet passage 12, sample cavity 11, drain passage 14 and to the disposal means 98 such that any sampling material that might remain after a sampling is removed. This air is also blown down the drain passage 14 such that any steam condensate that remains after the sterilization phase is completely removed. The pure air will both cool and dry the sampling system before the next sample is taken. The wash medium can be provided by the wash medium valve block 7 to clean the system if steam is insufficient. Likewise, a combination of steam and wash medium can be used. The pure dry air 70 can also be used to help flush the wash medium from the system and to dry the system after the use of wash medium.
The drain line block 9 will be open to drain away condensate, wash medium and the like during cleaning and sterilization. The sample vial block 8, on the other hand, will be open to allow the sample material to flow into the sample collector 94.
In
In the timing chart of
No valves are provided in the interior of the sample cavity 11 for preventing the sample from entering the inlet passage 12. The valves 67, 71 and 75 will be closed such that an internal pressure will be sufficient to prevent the sample from traveling up inlet passage 12. Moreover, gravity also prevents the sample from traveling up the inlet passage 12. The apparatus A is therefore simplified and can be used in existing vessels or conduits 53 without modification due, in part, to the omission of extra valves. In other words, the relatively small size of body 10 can be maintained such that it is compatible with existing vessel or conduit ports. Moreover, potential sites of contamination are avoided by omitting such additional valves.
After a sufficient sample has been collected at collector 94, another one-second delay is indicated in
As previously noted, the arrangement in
It should be appreciated that after the body 10 is mounted in the arrangement of
Feed/Inoculation Means
Up to this point, the instant invention, has been discussed as a sampling apparatus. As shown in
The feed/inoculation arrangement shown in
As indicated in
Indicated schematically in
Apart from having the end 48 of the drain passage 14 located at the end of the sample cavity 11, the diameter of the drain passage 14 is of a sufficiently small diameter such that the pressure in sample cavity 11 (created from inflow through passage 12) will be sufficient to force any material fed through inlet passage 12 up and out drain passage 14. In this manner, the particle size of the sample fed to the sample cavity 11 is limited by the size of the inlet passage 12. When the supply means 50 is operated, sufficient air, steam, and/or wash medium can be fed through the inlet passage 12 in order to force any sample or other contaminant through the drain passage 14 to the means for collecting 52. Otherwise, the design of the feed/inoculation arrangement shown in
Advantages
The instant apparatus A has several advantages. Its geometry will enable the body 10 and its contents to be relatively small such that it can be retrofitted into existing vessels or conduits. For example, the 25 mm standard size for ferrules 1 can be accommodated with the instant invention.
The instant invention provides a uniquely designed biocompatible, resterilizable flexible diaphragm which allows the sample extraction orifice to be flush mounted with or penetrated into the vessel or conduit 53. A customized subassembly design is possible in which all of the contamination-prone opposing sliding/rotating surfaces are sealed from the sample. For example, the bellows 30 separates and isolates a sample from the operating portions of the valve 49. Other control features such as the steam feed valve block 5, pure dry air valve block 6 and wash medium valve block 7 are removed from the sample. Since contamination-prone parts are removed from the process, the instant apparatus A is a more effective overall sanitary design.
The instant apparatus A is free-draining and will avoid pooling. Pockets between the sample cavity 11 and the drain passage 14 are not present such that pooling or accumulation of a sample or drain is further avoided.
With the exception of seals about the cylindrical sealing portion 166 of rod 22, all secondary seals are static to provide the most effective barrier to leakage within the system and/or to the outside environment. Further, the interfaces between the abutting surfaces on the process side (where crevice-related carryover contamination often occurs) are sealed with the static seals (with the exception of the specially designed primary seal which is a diaphragm-type seal). The instant invention avoids the need for dynamic o-ring seals. Void volume in the sample cavity 11 is minimized. Tortuous flow is also avoided. Therefore, minimal loss of sample material during the sampling process and maximized reproducibility and accuracy of measured samples is had with the instant invention. By using small volumes, only small errors in measurements will be made.
Within this 25 mm outside diameter design discussed, the instant design permits particles of at least six mm outside diameter particles to pass from the vessel or conduit 53 through the sample cavity 11 and out of the drain line 14 to the sample collector 94. Therefore, physical distortion of the sample constituents is avoided, thereby assuring that samples taken are not biased due to size exclusion.
The trigger mechanism, which allows the valve to be rapidly opened and closed, allows more precise control of sample volumes and, at the same time, reduces sample waste. Furthermore, because sample volumes can be controlled much more precisely, even small volumes, operators will not have to resort to “throttling” which can cause physically and chemical changes in samples through shear. Lastly, the trigger actuator mimics the action of automated actuators. This means that its samples will correlate better with those taken using automated actuators then will other manual actuator designs.
The trigger mechanism and or the automated actuator can readily be added or removed from the valve, providing easier maintainability. Furthermore, because the valve is sealed and has the primary return spring within, these change-out operations can be done without affecting the valve's on-line service.
All static threaded connections and abutting surfaces of the instant invention are placed behind static o-ring seals. This removes trouble-prone interfaces from contacts with process flow.
The control means 4 and means for detecting 4a of the instant invention provide for automatic sampling or inoculation. Therefore, operator error is avoided. Manual override also permits sampling even in the case of power failure.
Pressure or temperature profiling of the system and independent indirect verification enables a more reliable operation.
Accordingly, with the instant invention, an accurate subsample of the process composition can be had. This arrangement can be used with existing systems or with new systems. Maintenance of the instant apparatus can easily be carried out.
Because the body 10 of the instant invention can be machined from a single piece of metal, plastic or other material, if so desired, the need for additional junctures is eliminated. This also avoids potential points for contamination to the sample. Also, the bulb design of the sealing tip 32 avoids dead space.
Due to the control means 4, the timing sequence can easily be changed. For example, an operator can change the length of each of the phases in the sampling process and, using feedback from the temperature and/or sensor probe 19, determine if any error has occurred in the system.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
Claims
1. A valve installed in an inclined ferrule in a wall of a vessel or conduit, an axis of an internal bore of said ferrule having an angle of inclination in a direction away from the vessel or conduit, comprising:
- a valve body, said valve body having an internal drainage path with an angle of declination in a direction away from the vessel or conduit greater than or equal to said angle of inclination of said axis of said internal bore of the ferrule, a forward end of said internal drainage path having an orifice; and
- a valve operating rod having a sealing tip engageable with said orifice for opening and closing said orifice, said valve operating rod having an axis at an angle to an axis of said internal drainage path.
Type: Application
Filed: Nov 22, 2004
Publication Date: Nov 17, 2005
Inventor: Douglas Newberg (Plainsboro, NJ)
Application Number: 10/993,171
