Chemical Reactor System and Methods to Create Plasma Hot Spots in a Pumped Media
Methods and apparatus are disclosed to produce gas vapor bubbles in a liquid media and collapsing the bubble to create a plasma hot spot. Generated bubbles are introduced and collapsing the bubbles results in the partial or total conversion of the internal and boundary layer gas and liquid phase content of the bubble to plasma, ionized gas and ionized liquid. Consequently, a change or increase in the reactivity of the elements and compounds in the gas or liquid phases of the bubble and the surrounding liquid media occurs.
This application claims the benefit of the priority of U.S. Provisional Application Ser. No. 61/385,392, filed Sep. 22, 2010, and U.S. Provisional Application Ser. No. 61/385,423, filed Sep. 22, 2010, the entire disclosures of which are expressly incorporated herein by reference.
FIELD OF THE INVENTIONThe present invention relates to pump systems and controllers to create an automated, customizable, chemical reactor.
BACKGROUND OF THE INVENTIONCavitation caused by ultrasonic and hydrodynamic equipment and techniques has been used for catalysis of many known and well defined endothermic reaction traditionally implemented with high temperature/high pressure processes for many years. The advantage of cavitation as a mechanism of chemical catalysis is the effect of high pressure and temperatures achieved in the domain of effect near the collapsed bubble, the rate of heating being sufficient to start and sustain reactions in aqueous and other solutions. Reactions catalyzed by these means are numerous and include hydrolysis, hydrogenation, transesterification, hydrodesulfurization, polymerizations, protonation, and others. The field of ultrasonic sonochemistry is well established and the techniques of sonication as a catalyst for reduction and oxidation chemistry and numerous organic and inorganic degradation and synthesis processes based on aspects and principles of sonochemistry have been in use in academia for experimentation and production of exotic chemical species for many years.
Implementation of hydrodynamic cavitation and sonochemistry for commercial or industrial scale resource processing, chemical synthesis, waste recovery, recycling and remediation has arguably been curtailed by the nature of the mechanism used to catalyze reactions for these purposes—cavitation. While single bubble collapse as achieved in single bubble sonoluminescence has been demonstrated as a stable, controlled bubble collapse technique using the methods of ultrasonic cavitation, cavitation as applied in industrial processes almost invariably use multi-bubble cavitation as the catalytic mechanism. This technique, when used at high power levels on raw materials that are variable in composition, such as metal or mineral ores, mining influenced waster water, chemical process effluents, crude oil, waste biomass, surface or ground waters that have stratified and are compositionally variant based on location or depth or as a consequence of long detention, requires significant and continuous modification of process conditions to sustain economically feasible throughput rates. These types of changes to cavitation bases mechanism are difficult as both ultrasonic and hydrodynamic cavitation require limited and specific conditions to achieve the high temperature and pressure collapse characteristics required to sustain productive rates of specific reaction catalysis.
Ultrasonic sonochemical processes are dependent on specific frequencies, or specific ultrasonic wave generation surface or horn travel distances or both. Once these variables are optimized in process, changes to reagent composition, ambient pressures, temperature, dissolved gasses or other solvent or solute properties often immediately destabilize the bubble cloud formation and collapse, significantly halting or slowing reaction catalysis, rendering the continued application of the technique without process variable changes uneconomic. Adjustments to frequency and amplitude of the ultrasonic field directly affect the properties of the created and collapsing bubble, changing the resonant frequency. The changes to frequency or amplitude, ambient pressure, temperature or other solvent or solute properties may result in condition that, while producing cavitation, produce bubbles with properties of size, resonant frequency or collapse rate that are not optimal for the catalyzing the desired reactions or processing of the feedstock in its current condition. This limitation is due to the dependence of bubble properties on ultrasonic field frequency and amplitude. The bubble properties can be modulated through advanced process control of these process parameters, but only certain frequency and amplitude combinations are effective. As a consequence, reactive closed loop control of processes based on this mechanism is limited in the scope of variation, detrimentally affecting the economics of processes using this mechanism of reaction catalysis.
There are many hydrodynamic cavitation implementation techniques using a variety of methods to manipulate the formation and collapse of bubbles through pressure and flow control. In addition, custom fittings and shaped orifices and other fixture based techniques for laminar and other unusual flow patterns, with and without closed loop control, have been in used to produce cavitation and catalyze compositional degradations and synthesis. Hydrodynamic cavitational techniques also suffer from restrictions due to optimal condition requirements similar to ultrasonic cavitation, where variation in composition, viscosities, dissolved or suspended solids content, dissolved gasses and other properties of the solvent or solute detrimentally affect the properties and formation of the clouds of bubbles and their subsequent collapse rates, shapes and characteristics.
Both ultrasonic and hydrodynamic cavitation also result in cavitational damage to process circuit elements as conditions for controlled cavitation often result in insipient or other undesirable cavitational effects at or on surfaces or system components, resulting in component wear, significantly affecting process economics.
SUMMARY OF THE INVENTIONThe present invention provides a solution to the aforementioned limitations of both hydrodynamic and ultrasonic cavitation. Rather than causing bubble collapse through cavitation, methods and configurations are provided to produce bubbles in a controlled way directly and then, also in a directly controlled way, collapse those bubbles at a specific rate to a specific size. In addition, the bubbles collapse while entrained in fluid flow, preventing undesirable bubble collapse upon process component surfaces. As the formation and collapse of the bubbles occurs independent of optimal flow, pressure, temperature, viscosity, and other solvent and solute properties, and the bubble sizes and collapse rates are directly controlled and not a function of effective ultrasonic amplitudes or frequencies, or fixed pressure or flow established in specialized fittings, this mechanism of bubble collapse can be applied to catalyze reactions economically across a broad range of feedstock variability.
Methods and apparatus are provided to produce gas vapor bubbles in a liquid media and collapsing the bubble to create a plasma hot spot. Generated bubbles are introduced and collapsing the bubbles results in the partial or total conversion of the internal and boundary layer gas and liquid phase content of the bubble to plasma, ionized gas and ionized liquid. Consequently, a change or increase in the reactivity of the elements and compounds in the gas or liquid phases of the bubble and the surrounding liquid media occurs.
In one aspect, methods and apparatus are provided that use the properties of a collapsing gas vapor bubble in a liquid media as a catalyst for reactions between elements or compounds contained in the gas or liquid phases of the bubble, or as a catalyst for reactions between elements or compounds contained in the bubble and the elements or compounds present in the bubble containing liquid media.
In another aspect, methods and apparatus are provided to form gas vapor bubbles in a liquid media and to collapse them in isolation from each other using a controlled hydrodynamically generated pressure pulse of sufficient magnitude, both in rate of pressure increase and ultimate maximum pressure that the bubble vibrates, for example at its eigenfrequency, during collapse for a sufficient interval of time to permit the formation of a plasma hot spot within the gas and liquid phases of the collapsing bubble.
In yet another aspect, a device is provided that permits concentrations of the gas and liquid phase constituents of the bubbles formed in a pumped media at a pump system inlet to be both directly and indirectly controlled, at the time of formation and during evolution through the various possible bubble sizes through to collapse as the bubbles pass from the pump inlet's low pressure zone through the pump at increasing pressure and out the discharge at a particular controlled maximum pressure.
In still another aspect, a pump system is provided based on a regenerative turbine pump with components arranged to allow controlled bubble production and introduction into the pump inlet and subsequent collapse of the bubbles entrained in the helical flow of the pump within the individual bucket chambers formed by the regenerative turbine pump impeller, wherein the bubbles are collapsed singly without the interfering effects of the collapse of adjacent bubbles.
In another aspect, methods and apparatus are provided for electric motor driven pump speed and pressure control. The pump control system dynamically calculates optimal pump speed and pump system pressures for one of the alternate apparatus configurations or applications, to start and sustain the formation in the pumped media of a specific number of gas vapor bubbles of a particular size and then subsequently collapse the same bubbles at a particular rate to a specific ultimate final bubble size.
The pump control system incorporates a controller that provides a speed setpoint signal to the pump motor drive and pressure setpoint signals used to operate pressure regulating valves controlling pump inlet, casing and discharge pressures.
The following description, with attached diagrams, provides details of the important aspects of the invention. Note, however, that the invention has other useful and novel aspects apart from those discussed. These additional aspects and advantages of the invention will become apparent when considering together the following detailed description and drawings.
The apparatus of the present invention comprises several independent subsystems that can be configured as required by a particular application. The apparatus includes a regenerative turbine pump to effectively entrain and collapse bubbles.
Referring to
When the regenerative turbine pump 60 is operating, the pumped liquid media will flow from the liquid supply 20, through the pump inlet pipe 22, then through an inlet pressure control valve 24 with a motorized inlet valve pilot regulator 26. The controller 100 actuates the motorized inlet valve pilot regulator 26 as directed by controller logic 101 and application logic 106 in response to conditions in the pumped media at the pump inlet pipe 22, such as pressure and temperature measured by inlet pressure and temperature sensors 111 and 112, respectively. Pump inlet pressure sensor 111 may include pump pressure element 111a, pump pressure transmitter 111b and pump pressure indicator 111c. Temperature sensor 112 may include temperature element 112a, temperature transmitter 112b and temperature indicator 112c. The sensors comprise a detector element to measure and a transmitter to send the value. While the sensors are shown as discrete devices, the sensors could be a single device. Values sent from transmitters are shown to users on indicators, which can be local or remote gauges or computer graphical monitors. An example of a suitable commercially available pressure sensor/transmitter is Ashcroft Xmitr, 0-100 psi, 3″. The primary control algorithms, operation and detection sequencing instructions and setpoints or setpoint algorithms, are stored in the controller, which can be a PC, Panel-PC, PLC (programmable logic controller) or some other specific purpose programmable HMI (human-machine interface) device or controller. An example of a suitable commercially available PLC is Allen-Bradley Micrologix 1400 Model 1766-L32BWAA. An example of a suitable commercially available PLC software with PID algorithms is RSLogix 500 Professional. An example of a suitable commercially available PC is HP Compaq dx2450.
The controller 100 calculates and adjusts the pumped liquid media pressure setpoint downstream of the inlet pressure control valve 24 by adjusting the inlet pressure control valve 24 using the motorized inlet valve pilot regulator 26. These adjustments could be made using the inlet pipe 22 pumped media condition information gathered by the pump inlet pipe 22 sensors 40, 111, 112, regulating pressure as required by the inlet bubble generation apparatus 30 and enabling sustained generation of bubbles of the required size and number for a particular application. Inlet bubble detection apparatus 40 may include sensor element 40a, transmitter 40b and indicator 40c.
Depending on the specific application and the nature of the pumped media, proper pressure control of the pumped media flowing through the pump inlet pipe 22 may include detection of other parameters of the pumped media's composition or condition, either apart from or in addition to temperature and pressure, such as flow rate, viscosity, two-phase void fraction, salinity, pH, total VOC (Volatile Organic Compound), BOD (Biological Oxygen Demand), or some other property or metric. When detection of conditions other than current pressure and temperature are used by the controller 100 to regulate apparatus inlet pressure, the controller logic 101 and application logic 106 may contain steps that detect and identify the additional sensors and evaluate the values therefrom in conjunction with the measured inlet pressure and temperature, calculating a new position setpoint for the motorized inlet valve pilot regulator 26, which in turn adjusts the position of the inlet pressure control valve 24, regulating the pressure in the pump inlet pipe 22 at the bubble generation apparatus 30. In this way, changes in liquid supply temperature, pressure or other parameter values that occur during the operation of the apparatus, such as a level drop in a liquid supply 20 tank, turbulence in pump inlet pipe 22, performance change in an upstream connected process, change in pressure of liquid supply 20, or a change in the flow rate requirements of the downstream subsystems can be detected and compensated for using closed-loop control, maintaining pressure and flow as required by the bubble generation apparatus 30.
Next, continuing with
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As a result of this sparging action, the gas or gas mix supplied is dissolved into the liquid supply as a function of the solubility of the supplied gas 252 in the supplied liquid 20 at the pressure maintained in the liquid supply 20. The saturated liquid is drawn across the venturi 270 by action of the regenerative turbine pump 60 resulting in a pressure drop in the venturi throat 272, as controlled by the speed of regenerative turbine pump 60, pump inlet pipe 22 or discharge pipe 75 pressure regulation, liquid supply pressure or some combination of thereof. As the gas-saturated pumped liquid media passes through the venturi throat 272, some of the dissolved gas or gasses and some of the pumped liquid media vaporize. Consequently, bubbles are formed with elements or compounds contained in both the gas supply 252 and the liquid supply 20. The specific gas vapor fractions in a bubble are calculated for a particular application using Bernoulli's equation, considering the dynamic dissolved gas and liquid vapor pressures, the differential pressure caused by the pressure drop across the venturi throat 272, the velocity of the pumped media, the static operating pressure at the inlet of the bubble generation apparatus 30, and any other property of the pumped media that can affect the gas vapor composition of the bubbles. This method enables automatic mixing of the dissolved gas and pumped media liquid gas vapor compounds in the bubbles. An example of a venturi for use in the present apparatus is the Venturi Tee made by LASCO Fittings, Inc., Brownsville, Tenn.
Referring now to
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Referring now to
The rotational speed setpoint of the pump impeller 63, determined during application design, and then subsequently maintained or adjusted as required by the controller 100 (see
An example of a regenerative turbine pump for use in the present apparatus is the Regenerative Turbine Chemical Pump made by Roth Pump Company, Rock Island, Ill. Roth regenerative turbine chemical duty pumps provide continuous, high pressure pumping of non-lubricating and corrosive liquids. These regenerative turbine pumps are provided with one piece, machined self-centering impellers for operation with a wide variety of chemicals with process heads up to 1400 ft. (427 m.), 600 psi (40 bar), TDH at 3500 rpm, NPSH from 3 to 14 ft. (0.91 to 4.2 m.), and temperatures to 450° F. (232° C.). Another example of a regenerative turbine pump for use with the present apparatus is Dynaflow Regeneration Turbine Pump made by Dynaflow Engineering, Middlesex, N.J. Another example of a regenerative turbine pump for use with the present apparatus is Model MT5003P3T6 made by Warrender, LTD., Wood Dale, Ill.
Continuing downstream of the pump casing and referring to
Continuing with
Once bubble generation is underway, the optional discharge bubble detection apparatus 70 is used to detect and measure any bubbles that remain in the pumped media flow downstream of the regenerative turbine pump 60. If bubbles are detected in the discharge flow, where none should be present, or if bubbles larger than those that should be present are detected, then the discharge pressure setpoint can be increased.
An increase in regenerative turbine pump 60 discharge pressure can be accomplished in at least two ways. First, where the current discharge pressure setpoint, as regulated by the discharge pressure control valve 80, is less than the shutoff, or maximum, pressure of the regenerative turbine pump 60 while operating at its current speed setpoint, then the discharge pressure control valve 80 is used to increase the discharge pressure setpoint. Second, where the current discharge pressure setpoint is equal to the maximum possible at the current regenerative turbine pump 60 speed setpoint, then the impeller 63 speed setpoint is increased. Consequently, the maximum possible discharge pressure setpoint is increased. Once the regenerative turbine pump 60 impeller 63 speed setpoint is increased, additional upward discharge pressure increase and regulation is accomplished by increasing the discharge pressure setpoint of the discharge pressure control valve 80. In this way, the discharge pressure setpoint and the regenerative turbine pump 60 speed setpoint can be manipulated independently, allowing a particular application to achieve and sustain a particular discharge pressure setpoint, as required to collapse the generated bubbles, while at the same time varying the regenerative turbine pump impeller 63 speed setpoint. This enables the precise timing of the impeller buckets 64 (
Again, continuing with
The pumped liquid media and gas handling subsystems of the apparatus may be outfitted with relief, bypass or other unloader valves (not shown) and other safety devices and features as required by the nature of the particular application. Additionally, inlet and discharge isolation (not shown) and check valves (not shown) should be installed where required to prevent improper flow and to provide for apparatus isolation, testing and service.
Referring still to
The controller logic 101 stored and executed by the controller logic PLC 140 provides the controller 100 and the apparatus operational sequence and other functions. The controller logic 101 can be changed as required to include functions specific to a particular apparatus configuration.
The external link PLC 118 provides a direct connection and controller 100 interface to an external device or computer, direct access to the data and program code stored on or with the controller PLC 140 from an external device, and logic for automated or externally directed upload and download of reduction logic 106 and controller logic 101 and setpoint data 107, 108, 109. Where the apparatus is part of a larger system, the controller logic 101 can incorporate steps to accept directives from and report operational parameter values and status to an external system, computer or device. In these cases, the external link PLC 118 can be configured and programmed to marshal this external communication and control between the external device or computer and the controller logic PLC 140.
Note that
Individual subsystem controls and instrumentation may be grouped in the controller 100 by related function and may be monitored and controlled as a group by a discrete individual PLC, PC or other similar device. This permits discrete subsystem data storage and programming. In this way the addition, configuration change or removal of subsystems or subsystem components requires only the addition, change, reprogramming or deletion of those corresponding elements of the controller 100 directly responsible for the state detection or control of the affected subsystem or component.
Controller logic PLC 140 executes the controller logic 101 and application logic 106 program instructions that direct the operational sequence of the apparatus subsystems, as previously described, and responds to external computer or operator requests. PLC 140 also handles operational sequence interruptions and operational parameter value data requests generated by the subsystem controllers PLC 130, PLC 102 and PLC 104. PLC 140 may also be used for handling and maintaining overall operational status information and requests for this information transmitted from the subsystem controllers and for relaying setpoint and subsystem status information between the apparatus subsystems as they request such data or status for their operation. Operational limit conditions, error states and other events then occur during operation that require the apparatus to change operational mode, halt, reset or communicate an operational or component status or alarm to an operator, external computer or device may also be handled by the controller logic PLC 140.
The inlet pressure control PLC 130 receives from controller logic PLC 140, initially and periodically as required, inlet pressure setpoint 107 data, as values, value ranges or as an algorithm used to calculate a setpoint value or value range using pump inlet pipe 22 sensor 40, 111, 112 data. The inlet pressure setpoint 107 data values specify, for a particular application, the required pressure and/or temperature of the pumped media and/or the required amount and/or size of bubbles that emit from the bubble generation apparatus 30, or both. Additionally, inlet pressure setpoint 107 data may be provided for other properties of the pumped media at the pump inlet pipe 22 or of the generated bubbles. Inlet pressure control PLC 130 receives ranged analog or digital signal input from sensor transmitters whose elements are mounted at the bubble generation apparatus 30 inlet, such as the inlet pressure transmitter 111b and the inlet temperature transmitter 112b. Inlet pressure control PLC 130 is also connected to and receives a ranged analog or digital signal input from the inlet bubble detection apparatus 40, which may be interpolated to represent the size and number of bubbles detected. Utilizing inlet pressure control application logic 106 and inlet pressure setpoint 107 data, inlet pressure control PLC 130 monitors pump inlet pipe 22 temperature, pressure, and other properties, as well as bubble number and size, and recalculates continuously during operation the required target inlet pressure setpoint 107. During operation, the inlet pressure setpoint 107 required to maintain uniform, stable, continuous operation of the bubble generation apparatus 30, as specified by a particular application, may vary due to pump inlet pipe 22 or discharge pipe 75 turbulence, pumped media flow rate or temperature change, pump speed change, discharge pressure change, or change in another property of the bubbles or pumped media. As these changes occur, the properties of the generated bubbles may vary outside an application's specified range. Inlet pressure control PLC 130 can calculate a new inlet pressure setpoint 107 expected to mitigate the bubble property changes and restore bubble production to the application's specifications. This processing continues until interrupted by controller logic PLC 140, which can provide new inlet pressure setpoint 107 data or direct inlet pressure control PLC 130 to set a specific inlet pressure setpoint 107 and stop processing. In addition, the controller 100 can provide panel mounted operators (not shown) and pump inlet pipe 22 sensor indicators—inlet pressure indicator PI 111c, inlet temperature indicator TI 112c—that enable manual control of the inlet pressure setpoint 107. An inlet pressure setpoint 107 input via a panel operator may be processed by controller logic PLC 140 as setpoint data from an external device or computer would be and as a specific inlet pressure setpoint 107 with no additional processing by inlet pressure control PLC 130.
Once an inlet pressure setpoint 107 is calculated by inlet pressure control PLC 130 it is transmitted together with the current inlet pressure process variable to inlet pressure control PID 135. PID 135 continuously receives updated inlet pressure process variable and setpoint pressure values. PID 135 then calculates and transmits a ranged analog or digital signal corresponding to the position of the motorized inlet valve pilot regulator 26 required to set the inlet pressure control valve 24 to the inlet pressure setpoint 107. If the motorized inlet valve pilot regulator 26 is equipped with its own controller, inlet pressure control PID 135 will transmit a ranged analog or digital signal representing the inlet pressure setpoint 107 to the motorized inlet pilot valve's controller, which will in turn calculate the required pilot valve position to set the inlet pressure control valve 24 to the inlet pressure setpoint 107.
Alternately, controller logic PLC 140 can direct—either as part of its intrinsic logic or as commanded by an external computer or device or operator—inlet pressure control PLC 130 to use the analog or digital signal from the inlet bubble detection apparatus 40 as the inlet pressure control PID 135 process variable. Two sequential operational modes are employed to implement this control technique. First, inlet pressure control PLC 130, using the aforementioned inlet pressure setpoint 107 handling techniques and in conjunction with inlet pressure control PID 135, sets the inlet pressure so that the bubble generation apparatus 30 is operating within application specifications for bubble number and size. Second, the interpolated analog or digital signal from the inlet bubble detection apparatus 40 corresponding to the optimal bubble properties is captured and used as the controlling setpoint in place of the inlet pressure setpoint 107. This captured setpoint signal is continuously transmitted together with the signal from the inlet bubble detection apparatus 40, which in this case is used as the process variable, to inlet pressure control PID 135. PID 135 subsequently varies the position signal or pressure value transmitted to the motorized inlet valve pilot regulator 26, and consequently the regulated pressure at the bubble generation apparatus 30 inlet, in response to changes in bubble properties. In this way, closed loop control of the inlet pressure required by the bubble generation apparatus 30 is continued in response to the inlet bubble detection apparatus 40 signal. Inlet pressure control PLC 130 can continue its control operation in this alternate mode or switch back to inlet pressure setpoint 107, and detected inlet pressure process variable based control of inlet pressure control PID 135.
Once the motorized inlet valve pilot regulator 26 position is set, the inlet pressure control valve 24 can maintain the set pressure without further pilot control adjustment. Consequently, in applications where repeated or continuous change in or adjustment of the inlet pressure setpoint 107 does not occur during normal operation, the inlet pressure control PID 135 can be omitted or replaced with a proportional-integral controller (PI) or other similar, simpler, proportional controller. It is understood, however, that in many applications, fine control of inlet pressure setpoint 107 variations will be required to sustain optimal apparatus operational parameter values.
Once bubbles are generated, they pass through the regenerative turbine pump 60 and are collapsed. Discharge pressure control PLC 102 and pump motor speed control PLC 104 both contribute to the process of pump discharge 68 and discharge pipe 75 pressure control. Discharge pressure control PLC 102 receives discharge pressure setpoint 108 data from controller logic PLC 140, initially and periodically, similar to inlet pressure control PLC 130, as values, ranges or algorithms to calculate the discharge pressure setpoint. Discharge pressure control PLC 102 receives and monitors ranged analog or digital signals from the discharge pipe 75 mounted sensors: discharge pressure sensor 113; discharge temperature sensor 114, and discharge bubble detection apparatus 70, as well as any other properties of the discharged process water that the apparatus might be additionally equipped to detect. Discharge pressure control PLC 102 continuously monitors the various aforementioned discharge pipe 75 process variables and recalculates the discharge pressure setpoint 108 required to collapse the bubbles at the rate and to the size required by the particular application. Similarly to bubble generation control, bubble collapse rate, final bubble size, or total bubble collapse control may require variable discharge pressure and pump rotation speed setpoints as operational parameters change. Discharge pressure control PLC 102 monitors discharge pipe process variables and continuously recalculates the discharge pressure setpoint 108 expected to mitigate any variance from bubble collapse specifications for an application.
Operation of the discharge pressure control valve 80, through operation of the motorized discharge valve pilot regulator 82 by discharge pressure control PID 103, as directed by pressure control PLC 102, utilize signal types, signal processing, process variable selection—such as discharge pressure or discharge bubble detection apparatus 70 signal—and operational considerations and control techniques similar to the analogous pump inlet pipe 22 pressure control accomplished by inlet pressure control PLC 130 and PID 135, motorized inlet valve pilot regulator 26 and inlet pressure control valve 24. Remote control of the discharge pressure setpoint 108 by an external computer or device can be relayed through controller logic PLC 140 and discharge pressure control PLC 102. Also, as is the case with manual pump inlet pipe 22 pressure control, manual discharge pipe 75 pressure control is possible using panel mounted operators (not shown) and the feedback from the panel mounted indicators including valve position indicator 110, pressure indicator 111c, temperature indicator 112c, bubble indicators 40c and 70c, pump speed indicator 115, speed indicator 218, speed indicator 450, discharge pressure indicator 113c, discharge temperature indicator 114c and valve position indicator 116.
As hereinbefore set forth, the rotational speed setpoint 109 of the regenerative turbine pump 60 can be calculated by the controller 100 considering various factors. For example, the pump motor speed setpoint 109 must be high enough that the regenerative turbine pump 60, when its impeller (
To accomplish this, the controller 100 permits direct interaction between discharge pressure control PLC 102 and pump motor speed control PLC 104 and relays inlet bubble detection apparatus 40 interpolated data that provides the number of bubbles generated per minute (or other time interval) from inlet pressure control PLC 130, via the controller logic PLC 140, to pump motor speed control PLC 104.
Controller logic PLC 140, in addition to and in support of controller logic 101, also stores and distributes to the controller's subsystems PLC 130, 102, 104 upon request parametric data describing the operational performance characteristics and limits of the current configurations of the apparatus subsystems, including information about the installed regenerative turbine pump 60. This pump configuration information can include performance curve data based on the regenerative turbine pump's 60 rotational speed, providing specifications such as maximum discharge pressure, maximum rotational speed, or flow rate, horsepower requirement or NPSHr as a function of the rotational speed. This configuration data is used by the apparatus subsystems' control PLC 130, 102, 104 to verify setpoint data ranges and identify out of limit operational conditions and for operational error control. In addition to this standard pump performance curve information, data regarding the regenerative turbine pump 60 impeller's (
Controller logic PLC 140, using the stored subsystem configuration data, controller logic 101, application logic 106, and setpoint data 107, 108, 109, retrieves or calculates and then transmits at operation startup an initial discharge pressure setpoint 108 to the discharge pressure control PLC 102 and an initial pump motor speed setpoint 109 to the pump motor speed control PLC 104. The discharge pressure control PLC 102 then recalculates the discharge pressure setpoint 108 and transmits it, along with the process variable, either the pump discharge pipe 75 pressure sensor 113 signal or the discharge bubble detection apparatus 70 signal, to the discharge pressure control PID 103 so it can position the motorized discharge valve pilot regulator 82. If the bubble collapse rate is insufficient, or the final bubble size is greater than the application specification, or bubbles are to be totally collapsed and yet are still seen by the discharge bubble detection apparatus 70, then the discharge pressure setpoint 108 is increased. The newly calculated higher discharge pressure setpoint 108 is transmitted directly from discharge pressure control PLC 102 to pump motor speed control PLC 104. PLC 104 evaluates the current discharge pressure setpoint 108, and using the stored regenerative turbine pump performance data, in conjunction with the current pump motor speed setpoint 109, determines whether the maximum pressure at the current pump motor speed setpoint 109 is greater than the transmitted newly calculated higher discharge pressure setpoint 108. If the current pump motor speed setpoint 109 is too low, pump motor speed control PLC 104 calculates a new pump motor speed setpoint 109 to cause the regenerative turbine pump 60 to output at least the new discharge pressure setpoint 108 requested by the discharge pressure control PLC 102. Conversely, where the collapsed bubbles are too small or the calculated collapse rate is too great, the discharge pressure setpoint 108, and possibly the pump motor speed setpoint 109 can be lowered. Both of these processes can be implemented using a ranged analog or digital signal representing the speed setpoint, calculated by pump motor speed control PID 105 and transmitted to the variable frequency drive 126, which in turn varies the power frequency supplied to the pump's motor so that it rotates at the pump motor speed setpoint 109. The variable frequency drive 126 continuously returns operational status data, including current actual pump motor rotational speed, to the pump motor speed control PLC 104, which in turn relays this actual pump motor rotational speed data to the pump motor speed control PID 105 as the process variable. Once the final adjustment of the pump motor speed setpoint 109 is complete and bubble collapse occurs as desired, pump motor speed control PLC 104 can switch the process variable used by the pump motor speed control PID 105 from the actual rotational speed signal relayed from the variable frequency drive 126 to the bubble properties signal transmitted from the discharge bubble detection apparatus 70. As with inlet pressure control, the discharge pressure control PID 103 and the pump motor speed control PID 105 process variables can be switched as required between the actual discharge pipe pressure as detected by the discharge pressure sensor 113 or the discharge bubble detection apparatus 70 signal.
Once the minimum discharge pressure setpoint 108 for a bubble collapse rate and final bubble size for a particular application is achieved, fine pump motor speed setpoint 109 adjustment can commence. To accomplish this, pump motor speed control PLC 104 requests the current bubble generation rate from PLC 140, which in turn retrieves the current inlet bubble detection apparatus 40 bubble property values from inlet pressure control PLC 130. Once the current bubble production rate is retrieved, pump motor speed control PLC 104 then calculates the current impeller bucket (
It should be understood that to accomplish the timing between generated bubble and impeller bucket 64, and as a pre-requisite step of application design, the number of bubbles generated and number of impeller buckets should be coordinated so that the impeller can be rotated at the minimum speed to collapse the bubbles as required by an application using a particular impeller design and bubble generation apparatus 30 configuration.
The apparatus can be operated in one of at least three separate purpose modes: as directed by an external device or computer, or as directed by algorithms executed by controller logic PLC 140 using controller 100 and residing controller logic 101, reduction logic 106 and setpoint data 107, 108, 109, or manually using panel mounted controls and indicators. In each of these three modes, the operational parameter values and setpoints, or the algorithms used to calculate them, as well as the useful subsystem process variable identities, are known and are input as controller application logic 106 and setpoint data 107, 108, 109 intended and expected to achieve a particular operational result.
In another mode, where the controller 100 is used as a tool to determine the optimal operational parameter values and the identities of those process variables required to produce a particular functional result. In this experimental or application development operational mode, the setpoint data 107, 108, 109 submitted represent test value ranges, or are algorithms used to calculate test value ranges, and include target performance specifications for bubble production and collapse. In this mode, the application logic 106 can provide both an operational test sequence algorithm that controls how each setpoint should be varied across the submitted setpoint data 107, 108, 109 range, as well as an algorithm and criteria to evaluate each set of operational parameter values against the target application performance specifications. During test execution, application logic 106 stores those operational setpoints that provide useful results, either a good fit or a poor match to the target performance.
The controller allows automatic sequential execution of operational trials using electronically stored inlet and discharge pressure setpoint values or value ranges and pump speed setpoint values or value ranges that may produce desirable performance characteristics, as required by a particular application. The controller 100 automatically recalculates and varies the operational setpoints using the originally input setpoint values or value ranges and value modification algorithms residing in the controller. Alternately, the operational trials could be directed using an external computer, PLC or other functionally equivalent device to submit test setpoint data 107, 108, 109 and test application logic to controller PLC 140, through external interface PLC 118. Once testing is complete, result data can be read by or uploaded to an external computer or device for storage or further analysis. Rather than storing only criteria matching operational test data, all result data could be stored, locally in the controller 100 or on a remote computer or storage device for further analysis. In this way, an application protocol describing the operational conditions and process variable selections most likely to produce a desired result with the apparatus can be developed using the apparatus and controller 100 as reporting those setpoint combinations yielding desirable or best fit operational characteristics using controller residing result evaluation algorithms.
The controller can be used as an analytical tool to determine the optimal operational parameter values required for producing bubbles of a certain size and collapsing them at a specific rate to plasma hot spots or as required by a particular application. The controller allows automatic sequential execution of operational trials using electronically stored inlet and discharge pressure setpoint values or value ranges and pump speed setpoint values or value ranges that may produce desirable performance characteristics, as required by a particular application. The controller automatically recalculates and varies the operational setpoints using the originally input setpoint values or value ranges and value modification algorithms residing in the controller. The controller concurrently records and subsequently analyses the trial operational results. In this way, an application protocol describing the operational conditions and process variable selections most likely to produce a desired result with the apparatus can be developed using the apparatus and controller as reporting those setpoint combinations yielding desirable or best fit operational characteristics using controller residing result evaluation algorithms.
Copending U.S. patent application Ser. No. ______, titled “Chemical Reactor System and Method using Regenerative Turbine Pump to Produce Fuel Gas,” discloses a particular application and is filed contemporaneously herewith. The disclosure of this application is expressly incorporated herein by reference.
If automatic control mode is initiated in step 1050, the setpoint data 107, 108, 109 is obtained from controller in step 1090, and step 1120 occurs. If manual control mode is initiated in step 1060, the setpoint data 107, 108, 109 are obtained from an operator panel in step 1100, and step 1120 occurs. If external control mode is initiated in step 1070, the setpoint data 107, 108, 109 are obtained from an external device in step 1110, and step 1120 occurs. In step 1120, the setpoint data is transmitted, the pump 60 and subsystems are started and the status is obtained. Thereafter, in step 1130 a determination is made as to whether the setpoint range is acceptable. If a negative determination is made, an input setpoint range error is thrown in step 1140, and the processing reverts to step 1030. If the setpoint range is acceptable, reduction logic 106 is performed in step 1150.
Next, in step 1160, a determination is made as to whether a subsystem error exists. If a positive determination is made, the processing reverts to step 1030. If no errors exist, a determination is made as to whether to initiate operational command in step 1170. If a positive determination is made, external or manual control mode operation command is processed in step 1180, and then, in step 1190, a determination is made as to whether to initiate new setpoint data. If a positive determination is made, the processing reverts to step 1050. If not, the processing reverts to step 1150.
If operational command is not initiated in step 1170, a determination is made as to whether there is a change in operational mode in step 1200. If a positive determination is made in step 1200, a determination is then made as to whether to halt the request in step 1210. If a positive determination is made, the processing reverts to step 1030. Otherwise, the processing reverts to step 1050. If operational mode change is not performed in step 1200, a determination is made as to whether to request subsystem data in step 1220. If a positive determination is made, the subsystem data request is processed in step 1230, and the operation of the system continues in step 1240, and the processing reverts to step 1150. Otherwise, the operation of the system continues in step 1240, and the processing reverts to step 1150.
It will be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. All such variations and modifications are intended to be included within the scope of the invention as defined by the appended claims.
Claims
1. A system for the formation and collapse of bubbles, the system comprising:
- a bubble generator for generating bubbles in a fluid;
- a regenerative turbine pump for receiving the fluid and the bubbles;
- at least one sensor sensing at least one process parameter associated with operation of the regenerative turbine pump; and
- a controller in communication with the at least one sensor, the controller receiving the at least one process parameter, processing the at least one process parameter, and adjusting operation of the regenerative turbine pump based upon processing of the at least one process parameter.
2. The system of claim 1, wherein the regenerative turbine pump includes an impeller blade defining a plurality of buckets.
3. The system of claim 2, wherein the buckets are sized to receive and move a singular bubble.
4. The system of claim 3, wherein the process parameter comprises at least one of the rotational speed of the buckets, discharge pressure, and temperature.
5. The system of claim 4, further comprising a bubble detection apparatus attached to the pump, the bubble detection apparatus sized to detect the number and size of the bubbles.
6. The system of claim 5, wherein the bubble generator comprises a venturi.
7. The system of claim 5, wherein the bubble generator comprises an eductor.
8. The system of claim 5, wherein the bubble generator comprises an injector for injecting the bubbles into the fluid.
9. The system of claim 4, wherein the controller transmits a speed setpoint signal to the pump and the controller calculates the speed, pressure, or flow rate of the pump.
10. The system of claim 9, wherein the system operates in a closed loop configuration.
11. The system of claim 10, wherein the at least one sensor senses at least one process parameter associated with operation of the bubble generator.
12. The system of claim 11, wherein the controller is in communication with the at least one sensor, the controller receiving the at least one process parameter, processing the at least one process parameter, and adjusting operation of the bubble generator based upon processing of the at least one process parameter.
13. A method for the formation and collapse of bubbles, the method comprising the steps of:
- producing a stream of bubbles from a liquid;
- delivering the stream of bubbles to a regenerative turbine pump having an impeller defining a plurality of buckets;
- collapsing the bubbles; and
- monitoring a process parameter associated with the bubbles using a controller and at least one sensor; and
- adjusting operation of the regenerative turbine pump based upon monitoring of the parameter.
14. The method of claim 13, wherein the bubbles are collapsed in individual bucket chambers of the regenerative turbine pump.
15. The method of claim 14, wherein the bubbles are entrained in a helical flow in the chambers of the pump.
16. The method of claim 15, further comprising the step of monitoring pressure or flow rate of the stream of bubbles using at least one sensor and the controller in communication with the at least one sensor.
17. The method of claim 16, further comprising the step of determining whether the pressure or the flow rate is within an acceptable range using the controller.
18. The method of claim 17, further comprising the step of adjusting operation of the regenerative turbine pump in response to monitoring of the pressure or the flow rate.
19. A system for the formation and collapse of bubbles, the system comprising:
- a bubble generator for generating bubbles in a fluid;
- a regenerative turbine pump for receiving the fluid and the bubbles;
- at least one sensor sensing at least one process parameter associated with operation of the bubble generator; and
- a controller in communication with the at least one sensor, the controller receiving the at least one process parameter, processing the at least one process parameter, and adjusting operation of the bubble generator based upon processing of the at least one process parameter.
20. The system of claim 19, wherein the regenerative turbine pump includes an impeller blade defining a plurality of buckets.
21. The system of claim 20, wherein the buckets are sized to receive and move a singular bubble.
22. The system of claim 21, wherein the bubble generator comprises a venturi.
23. The system of claim 21, wherein the bubble generator comprises an eductor.
24. The system of claim 21, wherein the bubble generator comprises an injector for injecting the bubbles into the fluid.
Type: Application
Filed: Sep 22, 2011
Publication Date: Mar 22, 2012
Inventor: James Charles BUTLER (Cherry Hill, NJ)
Application Number: 13/240,990
International Classification: F04B 53/00 (20060101);