Abstract: A motor control device includes a recording module and a controlling module. The recording module has a revolution speed table recording a plurality of predetermined revolution speed values. The controlling module receives a reference revolution speed control signal and measures the reference revolution speed control signal to correspondingly generate a reference measuring value. The recording module records the reference measuring value corresponding to one of the predetermined revolution speed values in the revolution speed table.

Abstract: A method for detecting compressor surge in a fuel cell system. The system includes a turbomachine compressor that delivers charge air to the cathode side of a fuel cell module. A bi-directional mass flow meter measures the airflow through the compressor, and provides an indication of a reverse airflow through the compressor for surge protection. A controller receives a signal from the mass flow meter indicative of the reverse flow. The controller controls a motor driving the compressor and a back pressure valve at the cathode exhaust of the fuel cell module to control the pressure in the fuel cell module to remove the surge condition.

Abstract: A fluid circulation pump (10) with synchronous motor (14), equipped with fluid heating device (40), particularly for washing machines or the like, of the type comprising a rotor (18), equipped with a permanent magnet being rotation-driven by the electromagnetic field generated by a stator (15) equipped with pole shoes (20) with the corresponding windings. This pump (10) has also a magnetic flux sensor (22) of the rotor (18) and a control unit (24) a signal from the magnetic flux sensor (22) at least a typical parameter of said fluid and a comparator this parameter with a reference value and to cut the power supply of the fluid heating device (40) off upon reaching a threshold of the predetermined reference parameter.

Abstract: A method for controlling a hydraulic system includes receiving an operator command signal via an operator command input device; receiving a throttle position signal from a throttle; retrieving from a memory a first predetermined correlation between the operator command signal and a corresponding command flow rate; retrieving from the memory a second predetermined correlation between the throttle position signal and a corresponding available flow rate from a hydraulic pump; determining the command flow rate based on the first predetermined correlation and the operator command signal; determining the available flow rate based on the second predetermined correlation and the throttle position signal; and providing a control signal based on the available flow rate and the command flow rate.

Abstract: A method of constant airflow control for a ventilation system is disclosed. The method includes various controls to accomplish a substantially constant airflow rate over a significant change of the static pressure in a ventilation duct. One control is a constant I·RPM control, which is primarily used in a low static pressure range. Another control is a constant RPM control, which is primarily used in a high static pressure range. These controls requires neither a static pressure sensor nor an airflow rate sensor to accomplish substantially constant airflow rate while static pressure changes. This is because these controls use only intrinsic control variables which are electric current and rotational speed of the motor. Also, the method improves the accuracy of the control by correcting certain deviations that are caused by the motor's current-RPM characteristics. To compensate the deviation, the method adopts a test operation in a minimum static pressure condition.

Abstract: An infusion device comprises a pusher for a plunger of a syringe containing a liquid to be infused. A load cell measures the push force. An encoder associated to a motor commanding the pusher measures the displacement of the pusher. A controller signals an alarm when the ratio between the variation of the push force and the displacement exceeds a predetermined threshold. The device, which serves for infusing an anticoagulant into an extracorporeal blood circuit in a dialysis apparatus, is able to signal an onset of an anomalous situation of lack of infusion in good time.

Abstract: In a flow rate estimation method of a blood pump, a general flow rate estimation formula which includes a correction term is formed based on a plurality of blood pumps. Measured data obtained from an objective blood pump implanted inside a patient is substituted into the correction term, thus forming a flow rate estimation formula of the objective blood pump. The flow rate Q of the objective blood pump is estimated based on the flow rate estimation formula and the values of the rotational speed N and the consumption current I of the motor of the objective blood pump, and the attribute data Z of the blood of the patient.

Abstract: A method of simulating water flow through a shower waste pump which is controllable by a water-flow detector, the method comprising the step of by-passing the water-flow detector with a water-flow simulator device. The in use simulator device simulates the presence of water and thus causes the shower waste pump to operate without the need for water. A water-flow simulator device is also provided.

Abstract: A method is provided for regulating fluid pump pressures by detecting an elevation differential between a fluid flow control device and the distal end of a fluid line in communication with the fluid flow control device. A fluid flow control device, for instance a peritoneal dialysis device, is at a first height, a distal end of a fluid line is at a second height, and a valved outlet, when open, affords communication between the fluid flow control device and the distal end of the fluid line. The elevation differential is correlatable with a pressure measurable during a calibration procedure provided as a part of the methodology.

Abstract: A method for detecting compressor surge in a fuel cell system. The system includes a turbomachine compressor that delivers charge air to the cathode side of a fuel cell module. A bi-directional mass flow meter measures the airflow through the compressor, and provides an indication of a reverse airflow through the compressor for surge protection. A controller receives a signal from the mass flow meter indicative of the reverse flow. The controller controls a motor driving the compressor and a back pressure valve at the cathode exhaust of the fuel cell module to control the pressure in the fuel cell module to remove the surge condition.

Abstract: An air compressor comprises a tank portion for reserving a compressed air, a compressed air generating portion for generating the compressed air to be supplied to the tank portion, a motor for driving the compressed air generating portion, and a pressure switch mechanism having a pressure sensor in a part of the tank portion, and controlling the motor to be turned on or off in accordance with an output of the pressure sensor, characterized in that when the time change rate of the pressure within air tank is greater than a predetermined value, the motor is restarted without waiting until the pressure decreases to the switch on point at the time of pressure fall.

Abstract: A control system for a work machine (101) including an electric machine (202), a hydraulic machine (204) and at least one hydraulic cylinder (108). The electric machine (202) is connected in a driving manner to the hydraulic machine (204). The hydraulic machine (204) is connected to a piston side (208) of the hydraulic cylinder (108) via a first line (210) and a piston-rod side (212) of the hydraulic cylinder (108) via a second line (214). The hydraulic machine (204) is adapted to be driven by the electric machine (202) and supply the hydraulic cylinder (108) with pressurized hydraulic fluid from a tank (216) in a first operating state and to be driven by a hydraulic fluid flow from the hydraulic cylinder (108) and drive the electric machine in a second operating state.

Abstract: A pump control system (20) for a pump (21) in a gas turbine engine (10) is described. The pump control system (20) comprises demand means (22) for providing a demand signal (23) relating to a required rate of fluid flow and/or pressure from the pump (21). The system also comprises sensing means (26) to sense at least one parameter of fluid downstream of the pump (21) and to provide at least one feedback signal (28) relating to the, or each, respective parameter. Comparator means (30) is provided for comparing the demand signal (23) with the, or at least one, feedback signal to provide a control signal (33) for controlling the pump.

Abstract: Method for controlling an assist pump for fluid delivery systems with pulsatile pressure. If for example a heart assist pump is driven with a constant number of revolutions, it is achieved, that the blood is also delivered through the assist pump, even when the heart chamber is in the decontraction phase. With the present method it is achieved, that an assist pump only acts supportingly in the pressure phase of the main pump, in such a way, that the pressure difference between the input side and the output side of the assist pump is continuously determined and the number of revolutions of the assist pump is controlled in such a way, that the determined pressure difference does not fall below a predetermined value and the rate of flow does not sink below zero.

Abstract: A system and method of surge limit control for turbo compressors including a turbo compressor having an inlet and an outlet, an anti-surge valve, a variable speed drive to operate the compressor, a rotational speed transmitter, an inlet temperature transmitter, an inlet pressure transmitter, an outlet pressure transmitter and/or guide vanes, and a controller, the controller including a PID control module wherein the computer uses information from the transmitters to continuously calculate a pressure ratio of the compressor at the compressor's current operational speed and compare it to the compressor's calculated pressure ratio at surge limit conditions. A computer generates a control signal for determining when to open the anti-surge valve if the pressure ratio of the compressor at the compressor's current operational speed guide vanes are within a user defined safety margin to the calculated pressure ratio at surge limit conditions.

Abstract: A pump controller is disclosed for controlling a pump for a fluid medium such as water. The pump controller includes a metal substrate (11) adapted to have a first side thereof exposed to the fluid medium and an insulating medium applied to a second side of the substrate. A pressure sensing means (12) including at least one pressure responsive element (R9, R10) is implemented on the insulating medium closely adjacent the substrate such that the pressure element is responsive to pressure of the fluid medium when the first side is exposed to the fluid medium. A flow sensing means (13) including at least one source of heat (15) and at least one temperature responsive element (16) is implemented on the insulating medium closely adjacent the substrate, such that the temperature responsive element is responsive to flow of the fluid medium when the first side is exposed to the flow, with the fluid medium providing a sink for the source of heat in a manner that is related to the flow.

Abstract: A drive arrangement for a conveying device for the conveying of a flowing medium is described, particularly for the conveying of air or fluid. The drive arrangement contains a drive engine whose rotational speed can be varied, an auxiliary motor that can be continuously controlled and a summing gearbox. The summing gearbox is connected on its output side with the conveying device and on its input side with the drive engine and the auxiliary motor. Furthermore, the drive arrangement contains a control unit that controls the auxiliary motor. In order to make possible an improved control or regulation of the conveying performance compared to linear, rigidly driven conveying devices, it is proposed that at least one magnitude of the condition of the flowing medium be detected by at least one sensor and to control or regulate the auxiliary motor of the drive arrangement by the control unit as a function of at least one magnitude of the condition of the medium.

Abstract: In the process according to the invention for determining a nominal values curve of an installation (Hinstallation(Q), Pinstallation(Q)) for controlling the pump capacity of a pump (6) driven by an electric motor (10) with speed control in a closed system with variable capacity requirement, first all consumers in the installation are closed, one consumer operation parameter is determined at a consumer (4-n) arranged at a distance from the pump, the pump capacity is varied until the consumer operation parameter has reached a predetermined value, and, once this value has been reached, a pair of pump parameters representative for the instantaneous pump capacity is determined and stored in the controller. This measurement is repeated with different consumers being open, and from the stored values of the pairs of pump parameters the curve of nominal values (Hinstallation(Q), Pinstallation(Q)) of the installation is calculated by way of a mathematical process for establishing a curve.

Abstract: The metering pump comprises a synchronous motor which is stepped down via a mechanical gear and the rotation movement of the motor is converted into a stroke movement which drives the membrane pump. To the motor there is allocated an electronic control which may be activated by external impulses with regard to the delivery quantity. At the same time the control operates such that one always passes through a complete operating cycle of the pump if the nominal delivery quantity resulting on account of the received impulses is as large or larger than the quantity which the pump delivers in an operating cycle.

Abstract: A system is disclosed for pumping fluids at desired average flow rates by applying a predetermined force to a pump chamber and pulsing an outlet valve of the pump chamber to deliver a fluid therefrom. In some embodiments, pump chambers are provided within removable pumping cartridges that are constructed and configured to be coupled to a reusable pump drive component. In other embodiments, the pumping cartridges include multiple pump chambers, which pump chambers are operated so that a pump flow rate of one pump chamber is a predetermined fraction of the pump flow rate of another pump chamber within the pumping cartridge.

Abstract: A method for determining the suction pressure of a centrifugal pump including the steps of determining pump torque and pump discharge pressure at at least two different speeds, forming a first order wave curve as a straight line using said pump torque and pump discharge and determining suction pressure from the y axis intercept of said line.

Abstract: A method and apparatus for achieving constant air flow rate economically utilizes an induction blower motor with control settings determining the motor excitation voltage. A memory stores, for a variety of motor speeds, a graph of the speeds plotted against a proportionality constant of flow rate to fan speed for the selected motor system on one axis and motor control settings on the other axis. The only monitoring necessary to achieve the constant flow rate is thus the sensing of fan rotational speed. The measured fan speed is compared against the proportionality constant needed for the selected constant air flow rate and a motor excitation voltage is derived to achieve that proportionality constant. When the system load changes significantly, thereby causing significant fan speed change, a cascaded control loop is used whereby the speed changed induced by each control voltage adjustment is monitored until the desired constant flow rate is again attained at the new load level.

Abstract: A fluid dispense system having a computer control system that operatively controls a stepper motor driving a pump. The stepper motor actuates the pump piston through partial revolutions. The computer control system determines the number of stepper motor steps required to pump a desired amount of fluid by the pump by rotating the piston through segments which are less than a full revolution. Further, the controller varies the speed of the stepper motor to avoid splashing of the dispense fluid and motor stalling.

Abstract: A safety device for use in a fluid transfer and/or circulation system of the type which uses a pump to draw water from a reservoir through one or more intake lines each extending from an open end at the reservoir to the pump intake. The safety device connects to the fluid transfer/circulation system and includes a sensor, a triggering mechanism, and a vacuum breaker. When the pump is operating, the sensor monitors one or more conditions of the system. When one or more of the monitored conditions deviates outside of a normal operational range, as a result of an obstruction of any one or more of the open ends of the intake lines, the triggering mechanism triggers the vacuum breaker to eliminate negative pressure in the system by introducing air from atmosphere into the intake lines, thereby removing suction at the open ends of the intake lines. The safety device may further activate warning devices including audible and visible alarms to indicate that the system has been deactivated.

Abstract: A piston-type infusion pump is provided having an improved method of occlusion detection. The infusion pump includes processing circuitry for controlling the drive mechanism to infuse medication to a patient, including a sensor to track the position of the syringe plunger, thereby metering the amount of medication dispensed to the patient. The processing circuitry also includes a force sensor for providing signals indicative of the presence of occlusions along the infusion path. The operation of the drive mechanism causes delivery of medication to the patient. The infusion pump is constructed to be watertight.

Abstract: Flow parameters in a fluid delivery assembly are determined by monitoring pressure responses and processing those responses along with information regarding the fluid flow. In one aspect, a processor controls the pump to pump flow quantities in accordance with a pseudorandom code. Portions of the resulting pressure signal sensed at the conduit is averaged, and the averaged values are then decoded in accordance with the pseudorandom code. An estimate of the equilibrium pressure is generated from the decoded average pressure values, while a summation of the pressure samples is generated from the undecoded pressure signals. The resistance to fluid flow of the system is determined from the estimated equilibrium pressure and pressure summation. For low flow rates, a processor controls the pump to pump fluid in a series of fluid boluses, with each fluid bolus delivered in the beginning of a separate timeslot.

Abstract: A control device is herein disclosed which comprises a drive piston 12p for changing the position of a slanting plate in a variable capacity pump 11, an electromagnetic proportional valve 13 for driving the drive piston, and a position detector 14 for detecting a position of the slanting plate. The control device performs a flow rate control of operating oil by controlling the electromagnetic proportional valve in accordance with a difference between a flow rate instruction value Fr for the operating oil and a position detection value from the position detector so as to change the position of the slanting plate. The control device further includes a pressure detector 18 for detecting a pressure of the operating oil supplied to an injection cylinder 10, and correcting means for correcting the flow rate instruction value on the basis of a pressure detection value from the pressure detector to output a corrected flow rate instruction value.

Abstract: The present invention provides a distribution pressure controlling apparatus comprising section for supplying water in a distribution reservoir to a distributing pipe network, section for detecting an outlet pressure of water, section for detecting an outlet flow of water, section for detecting a distribution pressure of the distributing pipe network, a fuzzy table for storing a relationship between a deviation between a distribution pressure set by a user and the distribution pressure, the outlet flow, and an outlet pressure target value correction amount for correcting an outlet pressure of water, outputting section for obtaining the outlet pressure target value correction amount from the fuzzy table, based on the deviation between the distribution pressure set by the user and the distribution pressure, and the outlet flow, for correcting an outlet pressure target value with use of the outlet pressure target value correction amount, and for outputting the outlet pressure target value thus corrected; and sec

Abstract: A flow sensor detects drops of infusion fluid that enter the drip chamber of an infusion system and generates a drop-detection signal indicating each drop detected. A setting controller receives the drop-detection signals from the flow sensor and counts the drops detected and then determines the fluid-flow rate of infusion fluid into the drip chamber. The setting controller then sets the infusion pump so that the fluid-flow rate of the infusion pump substantially matches the fluid-flow rate of the drip chamber. A motion sensor detects drip-chamber movement and generates a motion-detection signal indicating the motion state of the drip chamber. A maintaining controller is coupled to receive the motion-detection signal from the motion sensor. The maintaining controller also stores a signal that indicates a stationary drip chamber.

Abstract: A method and an apparatus are provided for stopping a motor-driven pressure generating pump of a system for coating workpieces with atomized liquid coating material in case of an empty material reservoir or a leakage in a material supply from a material reservoir to the pump or from the pump to an atomizer. The pressure and/or the volume flow at the pump outlet and/or the speed of the pump piston or a value dependent thereon are continually measured. The measured values are then converted to electric signals to be input to an electronic analyzer and analyzed therein. If, during operation, the pressure and/or the volume flow drops below a predetermined value and/or the speed of the piston exceeds a predetermined value, the electrically controlled driving connection between motor and pump or the power supply to the pump motor will be cut-off by output signals from the electronic analyzer.

Abstract: In a piston pump for pumping liquid carbon dioxide at a temperature below 30 degrees Fahrenheit and pressures at least as high as 7500 psi, the volume leaving the pump is determined by measuring only pressure or other parameter related to flow and movement of the plunger. The position of the piston is measured and the resulting displacement is integrated to determine volume of fluid pumped.

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 device for constant, automatic regulation of water pressure and flow in a water supply plant, comprising an electric pump fitted in the main water pipe, an adjustable pressure switch connected to the main water pipe, and an electronic control unit, which switches the pump on if the pressure falls short of a predetermined level or switches it off if a predetermined pressure level is exceeded. The device is characterized in that a turbine, incorporated in the water pipe, acts as a sensor, cooperating with a rotation signal transmitter which is connected to the electronic control unit in order to keep the pump switched on as long as the sensor detects a flow of water.

Abstract: Air handling apparatus (10) delivers a volume of air at a generally constant flow rate regardless of changes in the operating conditions of a system with which the apparatus is used. A blower (12) pushes air from one point to another. The blower is operated by a blower motor (14). A switch (16) controls application of power to the motor. Sensors (20) are used to sense the current drawn by the motor and the motor's operating speed. A flow controller (22) establishes a desired air flow rate to be provided by the blower. A processor (18) is responsive to the sensed current (I), motor speed (S), an input (C) from the flow controller, and constants (K1-K4) related to performance characteristics of the blower to determine a torque required by the motor to produce a predetermined air flow rate. The torque value is determined as a function of the combined motor speed input from the sensor and an input from the flow controller.

Abstract: In a magnetically suspended type pump, an operating state of the pump can be obtained without using a pressure gauge and a flowmeter. In addition, in the case where the magnetically suspended type pump is applied to a blood pump, in order to reduce the number of connections in a flow path and to avoid thrombus formation, a correlation between current flowing in a motor and flow or a correlation between current flowing in the motor and pressure is obtained in advance, and the speed of rotation of motor is varied by a speed of rotation control circuit in response to an instruction from a CPU circuit, based on the obtained correlation between current and flow or between current and pressure, whereby flow or pressure is controlled.

Abstract: A spray controller includes a governor which limits the current applied to an electric motor that operates a spray system pump. The controller accepts pressure sensing and pressure setting signals and provides a pulse train output to drive the motor whenever the sensor signal indicates that the output pressure is less than the "set" pressure. The governor accepts the spray pressure setting signal and limits the width of the pulse train as a function of the desired pressure setting, thus limiting the motor's current and speed. In the preferred embodiment, the motor's speed is restricted at lower pressure settings, but is allowed to operate at maximum speed at higher pressure settings.

Abstract: The invention is based on the premise that, for a given air blower, the current I consumed by the electric motor, the rotational speed N and the air flow rate Q are interconnected, regardless of the dynamic pressure, by a law Q=f(I, N) which can be experimentally determined on a ventilation bench. In order to perform any adjustment, I and N are measured, from which a calculator derives Q by means of the above-mentioned law. The comparison of the calculated value with the desired flow rate Qd provides an error signal which is applied to a control device which determines the supply voltage (U) of the motor of the blower. The invention is applicable to heating or air-conditioning installations for the passenger space of vehicles.

Abstract: A fluid pressure control system which is usable to control pressure in a fluid distribution system includes a variable speed drive coupled to a pump. A hydropneumatic tank is coupled to the distribution system. In normal operation, the variable speed drive actuates the pump so as to maintain pressure in the system. Under low flow conditions, a control unit, using the variable speed drive energizes the pump so as to pump fluid into and pressurize the hydropneumatic tank. The control unit then shuts off the pump. Pressure is maintained in the system, until a predetermined, lower, set point is reached as a result of pressure in the hydropneumatic tank.

Abstract: In order to reduce the overall size of serial pump arrangements, several block-disk-like building elements are used. These building elements are made of a non-metallic material and lie against each other with their control surfaces in a sandwich like stack. Two of the block-disk-like building elements have displacement chambers oriented transversely to the axis of the stack, in each of which is guided a push piston. Inflow and outflow bores in which the high pressure mass flow, for example a chemical buffer, is created, extend parallel to the stack axis. Both building elements form two serially arranged pumping units of the serial pump arrangement and ensure a constant and continuous mass flow. Check valves are provided at the suction and delivery sides of both pumping units. Besides saving space, this arrangement ensures a highly constant and continuous mass flow, as the throughflow paths are as short as possible.

Abstract: In order to create a safety device (1) by means of which reliable protection of the pump can be achieved as simply as possible, it is proposed that safety device (1) have a housing (4) provided with an inlet (5) and an outlet, inside which housing a first detection device with a transmitter element in the form of an impeller (7) provided with measuring blades (9) and a central part (10) are provided to determine the liquid throughput and a second detection device (24) in the form of a probe for detecting the liquid, both of which are connected with a control device for the pump.

Abstract: Control system for maintaining selected pressure in a gas distribution system including a header and multiple takeoffs from the header including a compressor to supply gas to the header at selected pressure range, a control valve in the header upstream of the first takeoff, an actuator to operate the valve to modulate flow to the header, a pressure transducer to measure the pressure of the gas in the header between the valve and the first takeoff, a controller to receive a signal from the pressure transducer and generate a controller signal corresponding to a valve position required to maintain the flow of gas to the header to maintain the selected pressure and a position control device to receive the controller signal and an electronic position feedback signal from the actuator to indicate the position of the valve with a comparator to compare the valve position signal with the controller signal and an operator to operate the actuator to move the valve in a direction to the position where the position feedba

Abstract: Apparatus and method for controlling an air distribution system of the type which includes a motor drivingly associated with a blower and a duct system, and further including a target air flow rate signal which represents a target air flow for the air distribution system. The apparatus and method provide control of the motor speed to maintain a rate of air flow in the system at substantially the target air flow rate regardless of the status pressure therein. The apparatus provides a speed signal representative of the speed of the motor, and a control signal in response to the target air flow rate signal and the speed signal, and controls the motor speed in response to the control signal. The central signal is provided independent of the duct system. Motor speed is controlled by applying a voltage to the motor which varies in accordance with the control signal for maintaining the rate of air flow in the system at substantially the target air flow rate regardless of the static pressure therein.

Abstract: A controller regulates a hydraulic pump for hydraulic equipment to allow long-term use of environmentally safe hydraulic fluids. This is accomplished by limiting the hydraulic pump power output to a level established to prevent the operating temperature from exceeding a specified level. A manual mode for switching between power curves permits alternate use of hydraulic fluids having different maximum operating temperatures. An automatic mode detects the type of hydraulic fluid and automatically selects and applies a suitable power mode curve to limit the maximum operating temperature to a value suitable for the detected type of fluid.

Abstract: A pressure washer is provided with a flow control switch and a bypass passage. The flow control switch shuts the motor of the pressure washer off when fluid is not being supplied to the pressure washer or when the spray gun of the pressure washer is closed. The bypass passage relieves excess outlet pressure and activates the flow control switch when the spray gun is closed. The pressure washer may include a soap pump for injecting soap into low pressure fluid at the inlet of the pressure washer.

Abstract: A water pressure control system in which the pressurizing pump is turned on only in response to low pressure but is turned off only in response to low water flow rates. Water flow is detected with a magnetic switch displaced by water movement. After the pump is turned on, it can not be turned off for ten seconds, to smooth operation. When the system is first activated, the pump is turned on for sixty seconds, without regard to the other control functions, to guarantee priming of the pump.

Abstract: Air handling apparatus (10) for delivering a volume of air at a generally constant flow rate regardless of changes in the operating conditions of a system with which the apparatus is used. A blower (12) pushes air from one point to another. The blower is operated by a blower motor (14). A switch (16) controls application of power to the motor. Sensors (20) are used to sense the voltage supplied to the motor, the current drawn by the motor, and the motor's operating speed. A flow controller (22) establishes a desired air flow rate to be provided by the blower. A processor (18) is responsive to the sensed voltage (V), current (I), and speed (S), an input (C) from the flow controller, and constants (K1-K4) related to performance characteristics of the blower to determine a torque required by the motor to produce a predetermined air flow rate. The torque value is determined as a function of the combined motor speed input from the sensor and an input from the flow controller.

Abstract: Transfer by pumping of effluents containing at least one gas phase and at least one liquid phase in a transfer line connecting a source of effluents is optimized by interposing on the line, between the source and the point of designation, a multiphase pump. The rotating speed of the pump is regulated so as to adapt the pump flow rate to at least one of the following parameters: flow rate variation well, variation of the volumetric ratio GLR or pressure drop variations occurring in the line during transfer. The values of the parameters are controlled and adjusted to values comparable with the operation of the pump.

Abstract: The present invention relates to a viscous material pump. According to the invention, a pressure sensor is associated with the hydraulic drive cylinder of the fixed displacement pump for generating a pressure signal when a first sudden pressure increase occurs after the drive piston moves out of its end position. The volume subsequently displaced by the conveying piston corresponds to the actual delivery volume during the pumping stroke. A processor calculates the actual delivery volume for each pumping stroke using the ratio between the stroke time, as defined by the occurrence of the pressure peak and the maximum available conveying volume of the cylinder, as defined by the stroke time the piston needs to move from its first to its second end position. The present invention further provides for adjusting the supply volume of a supply means discharging the material to the viscous material pump.

Abstract: The installation serves to adjust the flow rate of air in a network of ducts such as a mine. It comprises a fan (10) provided with an electric motor (16) powered at a variable frequency. The installation also includes a converter having an adjustable output frequency and measuring means (12, 22) for measuring the flow rate and the total pressure supplied by the fan. It also includes a processor (20), a memory (26) for storing in digital form at least one total-pressure/flow-rate characteristic curve, and optionally a pressure/flow-rate characteristic curve of the fan at at least one predetermined speed; means (30) for displaying said curves; and data input means enabling a reference value (Q.sub.

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.