Liquid separator for vacuum filter

Abstract

A float valve 80, made of HDPE, is movably mounted in a stainless steel cage 60 in an in-line vacuum filter. The float valve has a chamber 85 formed in a skirt portion 84 thereof. Float valve 80 has a generally cylindrical shaped outer surface 82 encircling the skirt portion 84 and a generally cylindrical shaped inner surface 83 encircling the chamber 85. A upper portion 86 extends across the upper end of valve 80 to form an inverted cup shaped body. The upper portion 86 extending across the upper end of said valve 80 has a threaded hole 87 formed therein to receive a threaded bolt 88 for forming a ballast to permit adjustment of the weight of said valve 80 so that it floats at a level that prevents it being drawn by venturi effect into the central air chamber 19 before a predetermined volume of liquid is collected in the cylindrical enclosure 11 through which air flows en route to the filter element 14. The water line is about 1 inch above the bottom edge of the skirt portion 84 and about 1 inch below the sealing surface 95 to assure that the float valve will engage a seal 98 on said cap 13 adjacent the lower end of central air chamber 19 before liquid is drawn into air chamber 19. The chamber 85 forms an air pocket in which air is trapped to lift the float valve 80 for positioning the sealing surface 95 a predetermined distance above the surface of water or other liquid in which it is floating.

Description

TECHNICAL FIELD

The invention relates to apparatus for removing and collecting droplets of water or other liquid in an in-line vacuum filter.

BACKGROUND OF INVENTION

This invention relates in general to air flow filter devices, and more particularly, to an industrial type in-line outer to inner flow vacuum filter with a transparent outer cylindrical enclosure so that a machine operator can easily see when it is time to disassemble and clean the filter of sediment and process debris buildup thereon equipped with “O” ring seals that are loose in the relaxed state facilitating repeated filter disassembly and reassembly yet subject to being drawn into the sealing state when a vacuum is drawn in the filter.

This application relates to improvements in devices of the type disclosed in U.S. Pat. No. 4,544,387, issued Oct. 1, 1985, to Charles G. Agerlid, entitled “Outer To Inner Flow Vacuum Filter With See Through Outer Enclosure,” the disclosure of which is incorporated herein by reference in its entirety for all purposes.

It is important to know when filter elements in an industrial type in-line air filter need to be either service cleaned or replaced. Air vacuum filtering systems used in vacuum packaging of, for example, foods and other substances where sediment and some debris are drawn off to the air vacuum system in the vacuum pack process require good filtering be provided in protecting the system vacuum pump from damage and for efficient pumping action. This requires not only use of a good filter but also knowing by visual inspection when a filter should be disassembled and cleaned. Further, it is important that service work requirements be as convenient as possible to facilitate quick and easy efficient service cleaning of filter air filtration elements. It is important that the vacuum system pull an adequate vacuum at the vacuum pack location and not just down stream from the filter. If the filtration elements are heavily clogged with sediment silt and process debris the vacuum system is reduced to not pulling an adequate vacuum to properly vacuum pack food and other product ingredients to provide proper protection from deterioration. Further, debris and sediment passed through a filter to a vacuum pump and some through the pump can possibly contaminate the environment where sanitation considerations are quite important. Furthermore, it is also important that vacuum system filter systems be cleaned of food debris often enough that undesired spoilage and bacteria growth are kept under control and the vacuum system is up to health and safety standards at all times. With frequent filter disassembly and reassembly for filter cleaning and servicing seal wear and damage can be and in many seal structures is a serious problem.

It is also important that droplets of water or other liquid be collected and efficiently removed from air flowing through the filter. Heretofore, spherical balls have been used in an effort to block the flow of collected water through the system. However, a hollow plastic ball is not aerodynamically shaped to form a suitable float valve in a system in which the flow rate of air is several hundred cubic feet per minute through a constricted area. The ball was drawn by rapidly moving air into outlet ports prematurely.

A long felt need exists for a float valve for use in vacuum filter systems which is suitable for use in close proximity to high velocity air streams that permits collection of water and blocks flow of water out of the filter to the vacuum pump under normal operating conditions.

SUMMARY OF INVENTION

The in-line vacuum filter disclosed herein is useable in a vacuum system including a filter cap having a central air chamber and arcuate slots formed in the lower surface of the cap, said arcuate slots being concentrically arranged around said central air chamber, said cap further having an inlet passage between the arcuate slots and an outlet passage communicating with the central air chamber. A transparent cylindrical enclosure extending into one of the arcuate slots forms an outer annular filter chamber. An inner liquid separator assembly is secured to the cap and extends into the outer annular filter chamber and has an inner cylindrical filter chamber formed therein.

A cage, having an upper end extending into one of said arcuate slots has an inner cylindrical filter chamber communicating with the annular outer filter chamber in the cylindrical enclosure and a float valve is movably mounted in said inner filter chamber in said cage, said float valve having a generally cylindrical shaped outer surface encircling a skirt portion and a generally cylindrical shaped inner surface encircling an air chamber. The air chamber is filled with air or other gas to assist in controlling the buoyancy of the float valve. The float valve must be light enough to float in liquid collected in the filter chamber but heavy enough to prevent it from being prematurely drawn upwardly by the flow of air through the system.

An upper portion extending across the upper end of said float valve forms an inverted cup shaped body with a top surface bounded by a beveled downwardly inclined conical sealing surface 95, having an upper circular edge and a lower circular edge, and a ledge extending around the lower circular edge and outwardly to intersect with the upper end of cylindrical surface.

A seal is provided on said cap adjacent the lower end of said central air chamber, said inclined conical sealing surface on said float valve moving into sealing relation with said seal when liquid accumulates in said outer filter chamber, said float valve being configured to float in accumulating liquid and to prevent the float valve being lifted by air flow through said inner filter chamber in said cage toward said central air chamber.

The water line is about 1 inch above the bottom edge of the skirt portion and about 1 inch below the sealing surface to assure that the float valve will engage a seal on said cap adjacent the lower end of central air chamber before liquid is drawn into air chamber. The chamber forms an air pocket in which air is trapped to lift the float valve for positioning the sealing surface a predetermined distance above the surface of water or other liquid in which it is floating.

The upper portion extending across the upper end of said valve has a threaded hole formed in the lower surface to receive a threaded bolt for forming a ballast to permit adjustment of the weight of the valve so that it floats at a level that prevents it being drawn by venturi effect into the central air chamber in the cap before a predetermined volume of liquid is collected in the annular outer filter chamber in the transparent cylindrical enclosure through which air flows en route to the filter element.

A specific embodiment representing what is presently regarded as the best mode of carrying out the invention is illustrated in the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

Drawings of a preferred embodiment of the invention are annexed hereto so that the invention may be better and more fully understood, in which:

FIG. 1 is a perspective view of an in-line filter having a liquid separator mounted therein;

FIG. 2 is a perspective view of an in-line filter having a liquid separator mounted therein; and

FIG. 3 is a crossectional view looking generally in the direction of the arrows taken substantially along line 3-3 of FIG. 1.

Numeral references are employed to designate like parts throughout the various Figures of the drawing.

DESCRIPTION OF A PREFERRED EMBODIMENT

Referring to FIGS. 1 and 2 of the drawing, the numeral 10 generally designates a vacuum filter having a transparent outer cylindrical enclosure member 11 extending between a bottom filter plate 12 and a top filter cap 13. Enclosure member 11 has indicia 11a on the surface which reads, for example, “Stop Vacuum Pump, Drain Liquid at This Level,” to warn operators that water or other liquid should be drained by opening a drain valve (not shown) in passage 12 a.

The top filter cap 13 has a threaded air inlet opening 16, that is connectable to a vacuum pack machine through an air line (not shown), communicating through an arcuate passage 17 between the transparent outer cylindrical enclosure member 11 and the outer surface of a cylindrical filter screen 14. Top filter cap 13 also has a center air chamber 19, that is an upper extension of an inner cylindrical filter chamber 20 within an inner liquid separator assembly 15, and therefrom a threaded air outlet opening 21 that is connectable to a vacuum pump through a vacuum line (not shown). In the illustrated embodiment, stainless steel nipples 16a and 21a are screwed into inlet and outlet opening 16 and 21.

The outer enclosure member 11 and is preferably a clear plastic tubular member with good optical properties and very high transparency formed of synthetic resinous material, such as acrylic, which is polymethyl methacrylate (PMMA) commonly known as by the brand names “Plexiglas” or “Lucite.” Acrylic is FDA approved, making it ideal for use in food service applications and offers a safe alternative to glass products, reducing problems with breakage and sanitation. “Plexiglas” is a registered trademark of Rohm & Haas Company. The material can be made with hydrophilic properties, which means that it has an affinity for water. Droplets of water or other liquid are attracted to and stick to the acrylic material and run down to the bottom of the clear plastic tubular member that forms outer enclosure member 11, which is, for example 10¼ inches long and has an outside diameter of about 5½ inches, with a wall thickness of one quarter inch.

Air containing droplets of liquid will impinge the inner surface of member 11 where the water is collected on the inner surface of the clear plastic tubular member 11.

Arcuate slots 33 and 35 are formed in the lower surface of cap 13 and are concentrically arranged around a central air chamber 19. Slots 33 and 35 have grooves 52 and 37 formed in inner walls in which O'ring seals 50 and 39 are mounted. The lower end of the wall 19a of central air chamber 19 has a groove 99 formed in the lower end thereof in which an O'ring seal 98 is mounted.

The transparent outer cylindrical enclosure member 11 and the inner liquid separator assembly 15 are held between the bottom filter plate 12 and the top filter cap 13 by a pair of stainless steel rods 22 threaded into threaded openings 23 in top filter cap 13 with the lower ends 27 of rods 22 extending through slots or openings 24 in bottom filter plate 12 and held in place by wing nuts 25 and washers 26 on the threaded lower ends 27 of rods 22. Vacuum gauge 28 is threaded into a sleeve 28a with internal and external threads secured in opening 29 in top filter cap 13 with opening 30 providing fluid communication with arcuate passage 17 that is an extension of an inlet opening 16.

Liquid separator assembly 15 comprises a cylindrical cage 60 and a float valve 80. Cage 60 preferably has a cylindrical wall with a perforated central portion 62 and non-perforated upper and lower end portions 64 and 66.

A generally conical shaped deflector 70 has an upper end 72, secure adjacent the upper end 63 of the upper non-perforated end portion 64 of the cylindrical cage 60, and has an outwardly projecting lower end 74 positioned above the elevation of the lower edge 65 of the upper non-perforated end portion 64 of the cylindrical cage 60. A mounting plate 61 is welded or otherwise secured to close the lower end 69 of the lower non-perforated lower end portion 66 of cylindrical cage 60 and an internally threaded nut 75 is welded to a central portion of mounting plate 61. The upper end of a thread rod 76 is screwed into nut 75 and secured in place by a lock nut 75a. The lower end of thread rod 76 is screwed into a nut 77 through a washer 77b and secured in place by a lock nut 77a. As illustrated in FIG. 3, nut 77a is positioned in a hole 77c in bottom plate 12. Mounting plate 61 has a drain/vent opening 78 formed therein to permit flow of liquid and gas through mounting plate 61 into the lower non-perforated lower end portion 66 of cylindrical cage 60. A piece of wire mesh 79 is spot welded over opening 78 to prevent entry of contaminants.

The conical shaped deflector 70 directs air into engagement with the inner surface of the plexiglass tubular member 11 such that droplets of water or other liquid are collected on the inner surface of the clear plastic tubular member 11.

A float valve 80 is movably mounted in cage 60 and has a chamber 85 formed in a skirt portion 84 thereof. Float valve 80 has a generally cylindrical shaped outer surface 82 encircling the skirt portion 84 and a generally cylindrical shaped inner surface 83 encircling the chamber 85. An upper portion 86 extends across the upper end of valve 80 to form an inverted cup shaped body. A threaded hole 87 is formed in the center of the lower surface of upper portion 86 for receiving a threaded end on a bolt 88, which functions as a ballast to permit adjustment of the weight of valve 80. Washers 88a may be added or removed from bolt 88 to further adjust the weight of valve 80.

The upper end 90 of valve 80 is beveled and has a top surface 92 bounded by a downwardly inclined conical sealing surface 95, having an upper circular edge 91 and a lower circular edge 96. A ledge 97 extends around the lower circular edge 96 and outwardly to intersect with the upper end of cylindrical surface 82. The angle or inclination of sealing surface 95 is about 30 degrees relative to top surface 92.

A float valve 80 is preferably formed of high density polyethylene (HDPE) which can be used in a variety of applications and industries where excellent impact resistance, high tensile strength, low moisture absorption and chemical-and corrosion-resistance properties are required. The material is light weight and meets FDA/USA food handling guidelines. In the illustrated embodiment, the float valve 80 is machined from round stock and has an outside diameter of 2.863 inches and an over-all height of 2.183 inches. The chamber 85 has a depth of 1.068 inches and a diameter of 2.443 inches. The diameter of the top surface 92 is 2.016 inches. Without the ballast bolt 88, the weight of float valve 80 is 4.5 ounces. With the ballast bolt 88 installed, the weight is 5.5 ounces. The weight is preferably adjusted such that the float valve 80 will float with the lower half submerged in water. The water line is about 1 inch above the bottom edge of the skirt portion 84 and about 1 inch below the sealing surface 95 to assure that the float valve will engage a seal 98 on said cap 13 adjacent the lower end of central air chamber 19 before liquid is drawn into air chamber 19. The chamber 85 forms an air pocket in which air is trapped to lift the float valve 80 for positioning the sealing surface 95 a predetermined distance above the surface of water or other liquid in which it is floating. The outer surface 82 is closely spaced relative to the inner surface of the cage 60 to prevent tipping of the valve member 80 which would allow the trapped air to escape. However, it moves freely upwardly through the inner cylindrical filter chamber 20 in cylindrical cage 60.

In the illustrated embodiment, the vacuum filter 10 is approximately 15½ inches tall and the outside diameter of cap 13 is about 7½ inches. In the illustrated embodiment, the cylindrical cage 60 is 7 inches tall and has an outside diameter of 3 inches. The outer cylindrical filter screen 14 is a 60 mesh screen supported on a stainless steel cylindrical cage 60, which is in turn supported by a ¼ inch stainless steel thread rod 76. It should be appreciated that the dimensions set forth herein are intended to assist in describing a specific embodiment of the general configuration of the invention and are not in any way limiting. The dimensions may change depending on operating conditions in other environments, such as air flow rate, pressure and other conditions that may vary for specific applications.

The upper end of cylindrical cage 60 of liquid separator assembly 15 is received, in annular groove 33 in the top cap 13 to help keep sediment out of inner vacuum chamber 20. The top of transparent cylindrical enclosure member 11, that is made of clear plexiglass tubing, is received in top plate annular groove 35, and the bottom of enclosure member 11 is received in bottom plate annular groove 36. O'ring 37, retained in inner rectangular in cross section annular groove 39 in the inner cylindrical wall of groove 35, seals the top of enclosure member 11 to the top cap 13 against outside to vacuum filter air leakage. A flat gasket 38 in groove 36 in bottom plate 12 sealingly engages the lower end of tubular enclosure 11. It is important that the “O” ring 37 and gasket 38 be generally loose sliding fits against the inner cylindrical surface of the enclosure member 11 at the top and against the end of enclosure 11 at the bottom thereof to permit frequent, perhaps daily, disassembly of the filter for cleaning of process debris and sediment from the filter screen 14. The loose O'ring 37 and gasket 38 allow such frequent disassembly and reassembly without material wear and yet when a vacuum is drawn within the assembled filter structures the “O” ring 37 and gasket 38 are drawn up tight to seal the spacing tolerance between the inner edge of the grooves 39 and 40 and the inner cylindrical surface of the transparent enclosure member 11 from leakage flow of air from the outside to the inside of the vacuum filter 10.

The inner liquid separator assembly 15 is a structural support element supporting the outer cylindrical filter screen 14 that is in the form, for example, of wire cloth of 304 SS (stainless steel), 40 mesh, 0.010 diameter wire. The cage 60 of inner liquid separator assembly 15 has staggered relatively large holes 46 with, typically, specification 16 gauge 304 SS (stainless steel) ¼″ staggered, 0.250″ diameter holes 5/16″ CTR (center spacing) 58 percent open. Thus, the inner screen provides the structural support for the outer screen that does substantially all the system filtering without the inner screen materially impeding air flow through the filter screen assembly as induced by system vacuum pump suction. Further, when it becomes apparent that screen 14 should be cleaned of sediment and process debris buildup thereon either visually through the transparent outer cylindrical enclosure member 11 and/or by excessive vacuum indication on vacuum gauge 28 the machine operator may easily and quickly remove wing nuts 25 and the bottom plate 12 along with transparent enclosure member 11, and the inner liquid separator assembly 15 and the outer filter screen 14 sub-assembly for quick wash flushing of process debris and sediment off and away from the outer surface of screen 14. It may be of interest to note that the lower plate 12 and cap 13 both may be made of high density polyethylene for long service life, sanitation and non-contamination reasons, enhanced ease of service and savings in cost.

Terms such as “left,”” “right,” “horizontal,” “vertical,” “up,” and “down” when used in reference to the drawings, generally refer to orientation of the parts in the illustrated embodiment and not necessarily during use. These terms used herein are meant only to refer to relative positions and/or orientations, for convenience, and are not to be understood to be in any manner otherwise limiting.

Whereas this invention has been described with respect to several embodiments thereof, it should be realized that various changes may be made without departure from the essential contributions to the art made by the teachings hereof.

Claims

1. An in-line vacuum filter useable in a vacuum system including a filter cap having a central air chamber and arcuate slots formed in the lower surface of said cap, said arcuate slots being concentrically arranged around said central air chamber, said cap further having an inlet passage between said arcuate slots and an outlet passage communicating with said central air chamber; a cylindrical enclosure extending into one of the arcuate slots forming an outer annular filter chamber, the improvement comprising:

an inner liquid separator assembly secured to the cap, said liquid separator assembly extending into said outer annular filter chamber;

a cage in said liquid separator assembly having an upper end extending into one of said arcuate slots, said cage having an inner cylindrical filter chamber communicating with said annular outer filter chamber and with said central air chamber;

a float valve movably mounted in said inner filter chamber in said cage, said float valve having a generally cylindrical shaped outer surface encircling a skirt portion and a generally cylindrical shaped inner surface encircling an air chamber;

a upper portion extending across the upper end of said valve to form an inverted cup shaped body;

a top surface bounded by a downwardly inclined conical sealing surface, having an upper circular edge and a lower circular edge; and

a seal on said cap adjacent the lower end of said central air chamber, said inclined conical sealing surface on said float valve moving into sealing relation with said seal when liquid accumulates in said outer filter chamber, said float valve being configured to float in accumulating liquid and to prevent the float valve being lifted by air flow through said inner filter chamber in said cage toward said central air chamber.

2. An in-line vacuum filter according to claim 1, said a upper portion extending across the upper end of said valve having a threaded hole formed therein; and

a threaded bolt forming a ballast to permit adjustment of the weight of said valve.

3. An in-line vacuum filter according to claim 1, said outer wall of central air chamber has a groove formed in the lower end thereof in which an O'ring seal is mounted.

4. An in-line vacuum filter according to claim 1, said seal on said cap adjacent the lower end of said central air chamber comprising: an O'ring seal in a groove formed in said central air chamber.

5. An in-line vacuum filter according to claim 1, said cylindrical enclosure extending into one of the arcuate slots forming an outer annular filter chamber comprises: a transparent cylindrical tube with indicia thereon to provide visual indication of the amount of liquid that has accumulated in said outer annular filter chamber.

6. An in-line vacuum filter according to claim 1, wherein said filter element means is two cylindrical concentric filter elements with the first element a fine mesh screen filter outer element; and the second element a structural support filter inner element having larger through air flow openings therein than the openings in said fine mesh screen filter outer element.

7. A liquid separator assembly configured to be mounted in an annular filter chamber in a vacuum filter, comprising:

a cage in said liquid separator assembly having an upper end, said cage having an inner cylindrical filter chamber;

a float valve movably mounted in said inner filter chamber in said cage, said float valve having a generally cylindrical shaped outer surface encircling a skirt portion and a generally cylindrical shaped inner surface encircling an air chamber;

a upper portion extending across the upper end of said valve to form an inverted cup shaped body;

a top surface bounded by a downwardly inclined conical sealing surface, having an upper circular edge and a lower circular edge, said air chamber forming an air pocket in which air is trapped to lift the float valve for positioning the sealing surface a predetermined distance above the surface of water or other liquid in which it is floating.

8. An in-line vacuum filter according to claim 7, said a upper portion extending across the upper end of said valve having a threaded hole formed therein; and

a threaded bolt forming a ballast to permit adjustment of the weight of said valve.

9. An in-line vacuum filter according to claim 8, with the addition of means for adjusting the weight of said float valve such that it will float with the lower half submerged in liquid wherein said float valve is positioned such that the surface of liquid is about 1 inch above the bottom edge of the skirt portion and about 1 inch below the sealing surface.