Abstract: A high-pressure unit (HPU) skid for greasing and actuating a frac tree valve includes one or more hydraulic pumps, a grease pump, a hydraulic reservoir, and two or more accumulators all of which are mounted on a portable frame. The HPU skid further includes fluidic connections to connect the frac tree valve to an output of the grease pump and fluidic connections to connect the frac tree valve to at least one of the two or more accumulators. The hydraulic pumps are configured to withdraw hydraulic fluid from the hydraulic reservoir for charging the accumulators, operating the grease pump, or charging the accumulators and operating the grease pump at a same time.

Abstract: A compressed gas supply unit has scroll compressors. Gas discharged from the scroll compressors travels through a main supply passage and is reserved in a reservoir tank, after which the gas is supplied to a gas recipient from a supply passage. The scroll compressors include inverter devices that allow for independent modulation of the speeds of respective drive motors. The controller includes a speed range setting unit that sets an upper speed limit and a lower speed limit of the scroll compressors, a speed sum calculating unit that calculates a sum of speeds of the scroll compressors based on a load of the compressed gas supply unit, and a speed setting unit that allocates the calculated sum of speeds among the scroll compressors to set speeds for scroll compressors respectively.

Abstract: Methods, apparatuses, and computer program products for controlling the torque load of multiple variable displacement hydraulic pumps are described herein. A pump displacement limit for each variable displacement hydraulic pump is determined using a nonlinear control law to limit the total pump torque load of the variable displacement hydraulic pumps on the engine. The value of the actual pump displacement of each variable displacement hydraulic pump is controlled based upon the respective determined pump displacement limit.

Abstract: A pump control system includes a controller coupled to first and second pressure sensors. The sensors couple serial pressure related information to the controller. The controller can evaluate respective liquid levels, in response to received pressure related information from the sensors. A current sensor coupled to the controller can provide signals indicative of operation of one or more pumps coupled to the controller. The controller includes circuits to detect the presence of predetermined faults and to emit an audible fault indicator in response thereto.

Abstract: A fan system for a variable air volume heating and/or air conditioning unit comprising a fan array with a control system to eliminate surge at low operating flows and to maximize operating range. The fan control system includes a fan pressure sensor for determining the pressure rise across the fan array and a fan airflow sensor for determining the total airflow generated by the fan array. A surge controller is programmed to constantly monitor the calculated surge pressure as the fan speed control is modulating the fan speed in response to user demands. As airflow increases or decreases in response to changes in fan speed, so will the calculated surge pressure. The surge control turn fans on and off to ensure that the operating fans are running in their optimum fan speed ranges. Thus, the fans in the fan array are prevented from reaching the surge point.

Abstract: The present invention is a controller specifically for pumps, making the benefits of variable frequency drive (VFD) technology more accessible to pump users. The present invention incorporates pump-specific system optimization software, an industrial grade drive, and a menu-driven user interface, offering protection, reliability, and ease of use not possible with other variable frequency drives.

Abstract: Apparatus (200) for the application of topical negative pressure therapy to a user of the apparatus (200) is described together with a method for protecting said apparatus (200) when subjected to abnormal stresses, the apparatus (200) comprising a device (202) and a waste canister (204) releasably connected thereto wherein the device (202) and waste canister (204) are connected together by clip means (222), said clip means (222) being subject to failure upon application of abnormal stresses thereby permitting separation of the device (202) and waste canister (204).

Abstract: A method is provided for regulating a charge air pressure of an engine having an exhaust gas supercharger, a fresh gas supply device, an air system having an air treatment system and a compressor chargeable by the supercharger, and an engine controller. The method detects an engine torque requirement; determines a current charge air pressure and a current pressure of the air system; compares the current charge air pressure to a target charge air pressure corresponding to the torque requirement, compares the current air system pressure to a target operating air system pressure, and regulates the charge air pressure by suppressing supply of compressed air from the supercharger to the compressor when the current charge air pressure is less than the corresponding target charge air pressure and the current pressure of the air system is greater than or equal to the target operating pressure of the air system.

Abstract: A self-adjusting fluid pump that includes a piston pump containing at least one piston with a pressure sensor. The fluid pump including at least one fluid-containing pump chamber within the piston pump, adjacent to said piston, wherein advancing the piston causes fluid flow from the pump chamber to a biological destination, and retracting the piston causes fluid to passively till the pump chamber. A microprocessor, senses piston pressure to calculate the rate of fluid input flow into the pump chamber for each pump cycle. If the output flow rate deviates from the input flow rate by a pre-specified value range, the microprocessor adjusts the piston pump to match the output flow rate with the input flow rate by increasing or decreasing stroke rate (piston velocity), stroke volume, or a combination of both.

Abstract: A system for measuring current in an H-Bridge motor drive circuit and using that current to determine the output of a device powered by the motor. A particular embodiment is disclosed for a motor-driven fluid pump. Motor current is measured at predetermined pump pressures and flow rates to create calibration tables relating motor current to pump pressure. Once calibrated, the system determines pump pressure based on motor current by referring to the calibration tables. In an embodiment, the pump is driven to achieve a predetermined fluid dispense profile. The system monitors pump pressure by measuring motor current and determines if the dispense profile is being achieved and sets alarms if predetermined thresholds are not maintained. The system also detects pump wear based on the current measurements and issues warnings to the user in such conditions.

Abstract: Embodiments of the invention provide a fire-extinguishing system for injecting foamant into a stream of water. The system can include a flow meter determining a flow rate of the stream of water and a foam pump having an inlet coupled to a supply of foamant and an outlet coupled to the stream of water. The system includes a servo motor driving the foam pump. The servo motor includes a sensor used to determine a rotor shaft speed and/or a rotor shaft torque. A controller can control an operating speed of the servo motor using closed-loop control depending on the flow rate and the rotor shaft speed and/or the rotor shaft torque.

Abstract: A method of pressure control for transmissions having a hydraulic circuit selectively communicating with first and second pumps via first and second regulators includes commanding communication to the hydraulic circuit to transition from the first to the second pump and the PCS to set the regulators to a high pressure-regulation level. The hydraulic circuit line pressure is raised to an elevated value exceeding a target value. The line pressure is lowered from the elevated to the target value at or after completing the transition to the second pump. The method may include transitioning communication with the hydraulic circuit from the second to the first pump. The PCS maintains the regulators at the high level and line pressure is raised to the elevated value. PCS sets the regulators to a low level, and line pressure returns to the target only at or after completing the transition to the first pump.

Abstract: Method for adjusting a compressed air installation using several electrically driven compressors of what is called the “loaded/unloaded” type and/or the turbo compressor type and/or the compressor type with variable rotational speed, wherein these compressors are each connected to a single compressed air network with their outlets, and wherein use is made of a control box which makes it possible to adjust the pressure in the compressed air network around a target pressure to be set. The adjustment takes place by controlling the flow of one or several of the compressors, in particular in order to increase the overall flow supplied by the compressors when the pressure drops too much, and in order to lower the overall supplied flow when the pressure becomes too high.

Abstract: A device (1) is designed for locating a region which is situated in a body (10). The device has a fluid-filled reservoir (30) which is closed off in a sealed manner by a displaceable plunger (32) and is connected to a hollow puncture needle (20). To measure the pressure prevailing in the fluid, the device has a pressure gauge (40). A signal converter (50) is used to convert a continuous pressure-measurement signal provided by the pressure gauge (40) into a form which is suitable for further processing. A synthesizer (60) is designed to process the converted pressure-measurement signal into a continuous sound signal which is representative of the pressure. If, during a displacement of the puncture needle (20), a needle point (21) reaches the anatomical cavity (15), the result is a readily perceptible change in the sound signal. The device records the pressure-measurement signal over the course of time.

Abstract: A system for cancelling or attenuating noise in at least two positive displacement compressors proximately located from each other for use with a heating or cooling system. A lead compressor and a lag compressor have a controllable rotational speed and phase of operation. A controller selectably controls the rotational speed and the phase of operation of each of the compressors. The controller controls the rotational speed of the compressors at substantially the same speed for each compressor, with a phase-lock loop and a comparator circuit for each compressor. The controller controls the phase of operation of the compressors through an oscillator so that the lead and lag compressor pressure pulses are spaced between successive outlet pressure pulses to effectively double the combined pulsation frequency for noise attenuation.

Abstract: A supply flow path for supplying a solvent is described. The supply flow path includes metering devices each with a piston, the metering devices being adapted for metering the solvent through separate source paths feeding the supply flow path. The supply flow path further includes a control unit adapted for controlling the metering devices' piston movement in accordance with solvent pressure, wherein a variation of the solvent pressure gives rise to a corresponding variation of a solvent volume contained in the supply flow path or a part thereof. The control unit is adapted for compensating for the variation of the solvent volume by corresponding movements or forward or backward displacements of the pistons.

Abstract: There is described a method and a system for cleaning an ink chamber (1) of a printing unit. The system includes a storage tank (10) which via a high-pressure pump (9) is connected with a hydrophore (2). In the hydrophore a high pressure is built up, and the hydrophore is connected with cleaning nozzles (40) via a valve (5). Thus it becomes possible to inject a shot of cleaning liquid into the chamber by switching the valves (5). The cleaning nozzles are preferably designed as a mushroom-shaped plug (40) with a stem (41) which is mounted in the chamber wall and which has a circular domed top (43) of elastic, resilient material. When injecting cleaning liquid, the elastic plug will spray cleaning liquid out into the chamber, and after shutting off the pressure, there will be a self-closing effect.

Abstract: A method for optimizing the operation of several compressor units in a natural gas compression station. After a second or further compressor unit is started, the speeds of the running compressor units are set according to a fixed speed ratio in relation to characteristic data established for each compressor unit. The fixed speed ratio is altered by adjusting the rate of flow to the same percentage via the speed of rotation until the preventive pump valves of the gas compressor station are closed, whereupon the operating points of the compressor units are guided, where possible, in the characteristic data thereof, to the maximum efficiency. The optimum set speed values are determined according to continuous operating characteristics of the gas compression station by coordinated variation of the set speeds of the compressors, taking into account fuel consumption of the gas compression station. The stored fixed speed ratio is adjusted according to the optimum set speed values thus determined and stored.

Abstract: Disclosed herein is a stable solvent delivery device capable of delivering solvent both at high pressure and at constant flow rate. A solvent delivery device comprises a plurality of plungers which reciprocate in the respective pump chambers including an eluent charge side pump chamber and an eluent discharge side pump chamber, a motor to reciprocate these plungers, a control unit to control the operation of the motor, valves which are respectively set at the eluent inlet and outlet of the eluent charge side pump chamber, a first sensor to measure the quantity of load received by the plunger in the eluent charge side pump chamber, and a second sensor to measure the pressure of the eluent discharged from the eluent discharge side pump chamber.

Abstract: A system is provided for attenuating noise in at least two positive displacement compressors proximately located from each other for use with at least one heating or cooling system. A lead compressor and a lag compressor have a selectably controllable rotational speed and a selectably controllable phase of operation. A controller selectably controls the rotational speed and the phase of operation of each of the compressors. The controller controls the rotational speed of the compressors at a predetermined rotational speed that is substantially the same for each of the compressors. The controller controls the phase of operation of the compressors by shifting the phase of operation of the lag compressor so that an outlet pressure pulse operatively produced by the lag compressor is substantially evenly spaced between successive outlet pressure pulses operatively produced by the reference compressor.

Abstract: An apparatus for boosting residential water pressure. To attain this, a conduit receives water supplied to a residence and routes the water through and inlet on/off valve and a first check valve to a pump, where said pump provides water to the residence as well as to a throttling conduit back to the input of the pump. In an embodiment, the water is returned to the input of the pump through a relief valve arranged within the throttling conduit. In an embodiment, a pressure switch provides input to a motor controlling the pump. Also, a method to increase water pressure.

Abstract: A screw compressor system comprises a plurality of screw compressors the capacity of each of which is controlled by repeating load operation and no-load operation. Using a timer output corresponding to compressed gas consumption in a demander including gas consumption equipments, a parent controller determines the number of compressors to be operated among the plurality of compressors. Among the compressors determined to be operated, all compressors other than one are put in load operation. In accordance with a load factor of the excepted one screw compressor, the parent controller controls discharge pressure of each compressor. At this time, the control is made so that discharge pressure of the screw compressor system measured by a pressure gauge be lower than that upon the maximum gas consumption.

Abstract: A sensor, system, and method for determining whether sufficient water is present to safely operate a pump. The sensor includes first and second conductive fittings that are physically and electrically isolated from one another by a third non-conductive fitting. Electrodes are secured to the exteriors of the first and second fittings and are electrically connected to an electronic detection device. The electronic detection device applies a voltage across the first and second fittings and detects a current flowing between the first and second fittings. The current is correlated to the presence of water between the first and second fittings. If the detected current is below a predetermined minimum, the electronic detection device turns off the pump to prevent dry-running thereof.

Abstract: A controller for managing a plurality of compressors in an efficient manner such that the system uses less energy, has lower maintenance cost and experiences less wear. For a system with multiple compressors the controller has the minimum number of compressors needed to maintain the pressure on at any given time and has no more than one compressor running in an unloaded condition for maximum efficiency. The system can quickly pressure up or down in conjunction with the needs of the system. The controller rotates the order of use of the compressors to spread the time of use and for limiting the number of times during an hour that each compressor can be turned on such that the compressors take turns running and turning on and off for even wear. The system seldom uses more than one compressor unloaded at any time.

Abstract: A control device for a diaphragm pump to feed a filter press or similar user unit comprising a three-phase electric driving motor for the pump which is connected to a supply main via a variable-frequency converter, which frequency converter has an analogue output at which a signal will appear which corresponds to the respective motor torque, a standard r.p.m. set-point adjuster to the input of which the actual signal is provided via an inverter and in which a graph is stored which produces an interdependences between the motor torque and the speed such that if the actual-signal rates are small the graph for the speed runs along a constant maximum value and if a preset rate is reached for the actual signal it gradually declines to a minimum value, and an attenuation member for the actual signal.

Abstract: A redundant, modular pump system includes a plurality of substantially identical pump modules. Each module includes constant speed drive circuitry, variable speed drive circuitry and a pump. Expansion is accomplished by adding modules. Reliability is enhanced by being able to operate each pump at constant or variable speed irrespective of whether other modules are being operated at different variable or constant speeds. A common, software driven control element activates drives and other devices in the modules to provide fluid on demand at a pre-selected pressure.

Abstract: A fluid compression system includes a plurality of compressors, each compressor having a local controller for controlling operation thereof and a sensor for sensing the pressure of compressed fluid discharged therefrom. A method for controlling operation of the fluid compression system includes establishing a set point pressure threshold for loading and unloading each compressor, and assigning a ranking to each compressor for identifying a highest ranked compressor and a lowest ranked compressor, whereby the highest ranked compressor for the compression system initiates all commands for controlling all of the lower ranked compressors in the compression system.

Abstract: A medical perfusion system for use in connection with the medical treatment of a patient is provided with a first type of perfusion device in the form of a blood pump adapted to pump blood through a fluid conduit connected to the patient and a second type of perfusion device in the form of a sensing device adapted to sense a condition and generate a sensing signal relating to the condition. The perfusion system also includes an electrical power network having an electrical power line, means for selectively connecting the perfusion devices to the electrical power network, and a controller with an input device for accepting control commands from an operator. The perfusion system could also include a control device, such as a pump, a plurality of sensing devices, and means for specifying the sensing device that the control device should be accept feedback from.

Abstract: A dairy chemical dispensing system for supplying an amount of at least one chemical to a utilization point in a dairy wash system, comprising: (a) an operator input controller for receiving operator input comprising input of a given amount of chemical to be supplied to the utilization point, and providing a signal corresponding to the operator input; and (b) a chemical dispenser in operative contact with the operator input controller, comprising a chemical source conduit, a pump connected to the chemical source conduit and to a chemical output conduit for supplying the chemical at a predetermined flow rate to the utilization point, a flow sensor connected to the output conduit for measuring an actual flow rate of the chemical through the output conduit, and a data processor electrically coupled to the pump and the flow sensor, where the data processor(1) receives the signal from the operator input controller, and based on that signal, determines a pump activation time necessary to supply the given amount of c

Abstract: A suction roll for a paper machine or the like including a perforated annular roll shell which is rotatable. A stationary suction box inside the roll shell with respect to which the shell rotates. The suction box is defined between two circumferentially spaced sealing ledges at the roll shell. A noise dampening chamber on the downstream side of the suction box defined by a further sealing ledge at the roll shell. A conduit communicating to the noise damping chamber to allow increased pressure in the chamber which reduces noise. At least one of a snifter valve, a suction blower, an air pump and a water pump communicating to the conduit for selectively adjusting the pressure in the noise damping chamber for damping roll noise.

Abstract: A multiple electric motor hydraulic oil pump power system including a programmable controller having electric motor starting and stopping circuitry for hydraulic oil flow control. The circuitry having means to compare each electric motor running hours and select the motor with the least running hours to adjust oil flow to the desired amount. The system monitors oil pressure and flow, comparing such pressure and flow with the desired value and automatically adjusting the system to accomplish the correction. The controller also maintains safety sensing devices for high and low oil reservoir levels, oil filter condition limits, oil temperature limits, and means to maintain a constant oil pressure under load with load flow rates varying from very low to very high.

Abstract: Balancing the load between compressors is not trivial. An approach is disclosed to balance loads for compression systems which have the characteristic that the surge parameters, S, change in the same direction with rotational speed during the balancing process. Load balancing control involves equalizing the pressure ratio, rotational speed, or power (or functions of these) when the compressors are operating far from surge. Then, as surge is approached, all compressors are controlled, such that they arrive at their surge control lines simultaneously.

Abstract: A fluid flow delivery system switches a variable speed pump drive among a plurality of pumps. The remaining pumps can be operated as constant speed pumps and can be energized one at a time in response to increasing demand. The pump associated with the variable speed drive can be operated over a variable output range to provide relatively low levels of fluid output, in response to low demand, and can be operated in combination with one or more constant speed pumps to provide increased levels of output fluid in response to greater demand levels.

Abstract: A vacuum pump control apparatus for an evacuating-type waste water collecting system is disclosed. In the system, waste water discharged from houses and facilities is collected into a water collecting tank by vacuum sewer pipes provided with a negative pressure therein, and the waste water collected in the water collecting tank is discharged by a booster pump while the air in the water collecting tank is discharged by a vacuum pump. The vacuum pump control apparatus comprises a gas-liquid ratio detection arrangement for detecting the ratio of the amount of air to the amount of waste water to be collected into the water collecting tank, and a control system for regulating the operating time of the vacuum pump based upon the gas-liquid ratio detected by the gas-liquid ratio detecting arrangement, so that a target value of the gas-liquid ratio is recovered when it falls below the target value.

Abstract: To control a solvent composition in a supercritical fluid system, a first pump pumps a first solvent through a first conduit into a mixer and a second pump pumps a second solvent through a second conduit into the mixer. First and second transducers measure the pressure in the first and second conduits and generate first and second signals proportional to the pressures. Each pressure signal is multiplied by a corresponding programmed concentration signal and compared to the programmed pressure in a feedback system to generate an error signal. The error signal is multiplied by concentration signals from a programmer to control the pumping rate of each pump. The pumps pressurize each fluid one at a time at the start of a run. The pressurization process is also used for producing disturbance-free flow as delivery is changed from one pump to another during prolonged runs.

Abstract: A multichannel pump system for HPLC and other uses has a plurality of fluid pumps whose input is fed separately to at least one high pressure mixing unit downstream of the pumps and any associated items such as pulse dampeners and pressure transducers. A pump controller is connected to control each of the pumps separately in a coordinated manner to provide a plurality of operational modes. The operational modes include an isocratic mode, in which optionally the output of solvent of like composition from two or more pumps is pooled to provide increased output capacity, as well as binary, ternary, etc., gradient modes in which different solvents are selectively mixed before being applied to an analytical unit such as an HPLC column. The pump system further includes a novel linear drive pump having interchangeable piston modules providing different ranges of flow rates. The linear drive pump is capable of providing precise solvent delivery at high pressure for flow rates from 20 ml/minute down to 0.

Abstract: A method and device for pumping a petroleum fluid passing through a pipe and having a quantity of gas and a quantity of liquid. The quantities of gas and liquid are measured to determine the weight of the fluid in a section of the pipe and, depending upon the relative quantities of the gas and liquid measured, an additional quantity of gas or liquid is added prior to the fluid containing the additional quantity being pumped. After the fluid has been pumped, the quantity of gas or liquid serving as the additional added quantity is sampled.

Abstract: A supervisory computer for a centrifugal compressor control system is disclosed which manipulates the set point of a controller for a valve in a recycle line from the compressor systems outlet to inlet. The supervisory computer manipulates the set point so as to both prevent surging and substantially minimize the recycling of compressed gas. The computer first determines the surge flow limit for the compressor based on prestored data from the compressors manufacture performance curves such as constant speed compressor curves, and the actual speed of the compressor. The controller then outputs a set point signal which periodically moves the control valve in incremental amounts toward the fully closed position. The periodic movement towards the closed position continues until the flow is close to the surge flow limit, or until the actual deviation of the setpoint flow and the actual process flow exceeds a desired high limit for this deviation.

Abstract: A heating and/or cooling system comprising a windmill for driving a first refrigerant compressor in parallel with a second refrigerant compressor driven by an electric motor or other power means. The second compressor operates the system when the wind velocity is low. When the wind velocity becomes high enough, the refrigerant pressure created by the wind driven compressor, is used to automatically shut off power to the second compressor. The wind driven compressor then takes over the function of the second compressor.

Abstract: A method and apparatus for controlling a compressor is disclosed wherein both the compressed air output and the speed of the compressor are simultaneously adjusted in relation to compressed air demand over a wide range of air demands and in a way so as to use less input energy during below-peak demand and automatically return the compressor to an operating condition of minimum speed and minimum power input when there is no demand on the compressor. A reciprocating piston compressor with at least two, and typically more than two, compression chambers driven by a prime mover has a separate unloader device for each compression chamber. A control assembly is responsive to tank pressures indicating demand on the compressor with the movement of one movable control member simultaneously operating both a control valve adapted for successively operating each of the unloader devices one at a time and a speed regulating member for the prime mover.

Abstract: A plurality of horizontally and vertically spaced apart remote liquid level sensor assemblies free of upwardly directed surfaces operatively connect only under emergency conditions to the sump tank of a sewerage system through vertical housings connected to horizontally extending drain lines connected to a sump tank and reliably indicate such emergency conditions for timely corrective action and avoid flood damage.