Abstract: A circulation pump assembly (22) includes an electrical drive motor (10) and an electronic control device (12) controlling the drive motor (10). The control device (12) is configured for the speed control of the drive motor (10) according to a control schema (I, II, III). The control device (12) includes a detection function (42) which is configured to detect a condition variable representing an operating condition, from a parallel flow path (16, 18, 20) with a second circulation pump assembly (22). The control device (12) is also configured such that it can change the control schema (I, II, III) on the basis of a condition variable detected by the detection function (42). Further an arrangement of at least two such circulation pump assemblies (22) and a method for the control of such two circulation pump assemblies (22) are provided.

Abstract: A method of sharing load between a plurality of parallel fluid pumps in a subsea fluid pumping system having first and second pumping units, each of which includes a respective first and second pump, the method including establishing a pump limit characteristics diagram for the first pumping unit by mapping a minimal allowable torque of the first pumping unit as a function of a differential pressure across the first pump, identifying a permissible operating region of the first pumping unit defined by a set of minimum allowable torque values for the first pumping unit, establishing a pump limit characteristics diagram for the second pumping unit by mapping a minimal allowable torque of the second pumping unit as a function of a differential pressure across the second pump, identifying a permissible operating region of the second pumping unit defined by a set of minimum allowable torque values for the second pumping unit, monitoring the torque of the first pumping unit and the differential pressure across the f

Abstract: Electronic systems for controlling submersible pumps are provided herein. In certain configurations, a pump system includes three or more submersible pumps used for pumping fluid from a reservoir, sensors used for generating sense signals indicating a fluid level of the reservoir, and a control circuit for selectively activating the pumps based on the sense signals so as to control pumping of fluids from the reservoir. In certain implementations, the control circuit is operable in a plurality of user-selectable operating modes associated with different pump activation sequences in response to the fluid level of the reservoir rising.

Abstract: A cooling system includes a fan group with a number of fans arranged in a row, a rail extending in a direction parallel to the row of the fans. A backup fan slidably mounted to the rail, a motor configured to control the movement of the backup fan, and a control board to determine whether there exists one malfunction fan in the fan group. When one abnormal fan exists in the fan group, the control board outputs a control signal to the motor, to enable the motor to drive the backup fan to move to a location corresponding to the abnormal fan.

Abstract: A cooling system includes a fan group with a number of fans arranged in a row, a rail extending in a direction parallel to the row of the fans. A backup fan slidably mounted to the rail, a motor configured to control the movement of the backup fan, and a control board to determine whether there exists one malfunction fan in the fan group. When one abnormal fan exists in the fan group, the control board outputs a control signal to the motor, to enable the motor to drive the backup fan to move to a location corresponding to the abnormal fan.

Abstract: A flood control system for use in a structure having a basement floor below ground level is provided. The flood control system comprises a sump, a main pump positioned in the sump, and a secondary pump positioned in the sum. The secondary pump is raised relative to the main pump to a predetermined elevation. The main pump is energized when a height of water within the sump is at a first level. The secondary pump is energized when a height of water within the sump reaches a second, higher level and is de-energized when a height of water within the sump drops to a third level. A cover is releasably mounted to the sump. The cover includes a first section for covering the main pump and a separate second section for covering the secondary pump. At least one of the first and second sections is hingedly mounted to the sump. A controller is operatively connected to the main pump and the secondary pump.

Abstract: An object of the present invention is to provide a reactor feedwater pump control system, wherein when a condensate pump is tripped, the decrease in feedwater flow of feedwater supplied to a steam generator is minimized to suppress the decrease in water level of the steam generator, and at the same time preventing operating condensate pumps from continuing a run out operation. The feedwater pump control system is provided with a feedwater supply system, which includes a plurality of condensate pumps disposed in parallel for boosting condensate water from a condenser; a plurality of reactor feedwater pumps disposed in parallel for further boosting and supplying the condensate water to a steam generator; and variable frequency power supply systems each for driving an electric motor of the reactor feedwater pump at an adjustable speed.

Abstract: A refrigerant system (10, 100, 200) is provided with a power control system (30, 130, 230). The power control system adjusts the speed of the motors driving the refrigerant system components such as a compressor, a fan or a pump via a variable speed device (75, 175, 275) or bypasses the variable speed device (75, 175, 275) for normal operating speeds. A single power control system may be provided for the entire refrigerant system or each component may be independently controlled.

Abstract: The invention provides a pumping system for delivering a plurality of different materials serially at a location at substantially the same flow rate wherein the system has a plurality of diaphragm pumps wherein each diaphragm pump has a first chamber for receiving a hydraulic fluid from a first and/or second hydraulic fluid source and a second chamber for receiving a material to be pumped from one of a plurality of pumpable material sources and wherein the system has a sensor for detecting the pressure of the hydraulic fluid in each of the first chambers of the plurality of diaphragm pumps which sensor is operable connected to a source of hydraulic fluid such that the sensor can activate the source of hydraulic fluid to ensure that the hydraulic fluid in each of the first chambers of the plurality of diaphragm pumps has an equivalent pressure at a time when delivery from one of the diaphragm pumps ceases and delivery from another commences; and a method of delivering a plurality of different materials at a lo

Abstract: A flood control system for use in a structure having a basement floor below ground level is provided. The flood control system comprises a sump, a main pump positioned in the sump, and a secondary pump positioned in the sum. The secondary pump is raised relative to the main pump to a predetermined elevation. The main pump is energized when a height of water within the sump is at a first level. The secondary pump is energized when a height of water within the sump reaches a second, higher level and is de-energized when a height of water within the sump drops to a third level. A cover is releasably mounted to the sump. The cover includes a first section for covering the main pump and a separate second section for covering the secondary pump. At least one of the first and second sections is hingedly mounted to the sump. A controller is operatively connected to the main pump and the secondary pump.

Abstract: An operation control devices and operation methods thereof so as to eliminates the difficulties in such a case of introduction of vacuum sensors and/or inverter control is disclosed. The disclosure relates to a control of plural sets of vacuum pumps. In order to comply with the subjects to overcome the difficulties, the disclosure proposes to utilize current detection approach instead of direct pressure detection approach, while showing how to estimate a vacuum degree achieved under the operation of the pumps as well as presenting a method on the control of the number of pumps. It is also described how organically a current detecting device, a vacuum degree estimating device, a working pump control device and related methods to satisfy the subjects are linked. The usefulness of the disclosure is also revealed.

Abstract: An actuator installed in a vehicle controls brake fluid pressures applied respectively to a first wheel cylinder for a front wheel and a second wheel cylinder for a rear wheel. The actuator includes a first pump for the front wheel, a second pump for the rear wheel, and a motor for driving the first pump and the second pump. The first pump sucks brake fluid and discharges the brake fluid to the first wheel cylinder. The second pump sucks brake fluid and discharges the brake fluid to the second wheel cylinder. In addition, a discharge volume of the first pump is larger than a discharge volume of the second pump.

Abstract: A gradient liquid feed pump system capable of liquid feed in a correct mixing ratio even in the case of liquid feed in which the mixing ratio varies. Specifically, it comprises a first plunger pump for sucking and delivering an eluate, a second the first and second plunger pumps through a cam, a first pressure sensor for measuring the pressure in the flow path of the second plunger pump, a second pressure sensor for measuring the pressure in the fist plunger pump, a cam position detecting sensor for detecting the cam position, wherein when the cam position is in a delivery interval, the rotary speed of the motor is increased, and the period for decreasing the rotary speed is determined on the basis of the difference between the pressure values obtained from the first and second pressure sensors, respectively. Thereby, liquid feed can be smoothly effected with correct mixing ratio while avoiding pressure interference between pumps.

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: A turbocompressor's Surge Limit Line, displayed in coordinates of reduced flow rate (q.sub.r) and reduced head (h.sub.r), can be difficult to characterize if the slope of the line is small; that is, nearly horizontal. And it can be especially difficult to characterize if the surge line exhibits a local maximum or minimum, or both. This is often the case with axial compressors having adjustable inlet guide vanes, and for centrifugal compressors with variable inlet guide vanes and diffuser vanes. With their prime objective being the prevention of surge-induced compressor damage and process upsets, antisurge control algorithms should compensate for variations in suction conditions by calculating both the operating point and the Surge Limit Line, utilizing specific (invariant) coordinates derived by using the notations of similitude or dimensional analysis. The result is that the surge limit is invariant (stationary) to suction conditions.

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 cooling apparatus for an electronic system, includes a coolant tank, main pumps, heat exchangers, a common supplementary pump, and supplementary check valves. The coolant tank temporarily stores a coolant. The main pumps are respectively arranged in a plurality of heat generators in the electronic system, and the main pumps supply the coolant from the coolant tank to the heat generators. The heat exchangers cool the coolant from each of the heat generators and return the coolant to the coolant tank. The common supplementary pump is operated when any one of the main pumps has failed and supplies the coolant from the coolant tank. Each of the supplementary check valves has an upstream side connected to an outlet port of the supplementary pump and downstream sides connected to outlet ports of the main pumps. Each of the supplementary check valves is opened when a pressure difference between the upstream side and the downstream side of each of the supplementary check valves is larger than a predetermined value.

Abstract: The present invention discloses a system for pumping a fluid into a common pressure outlet. The system contains a plurality of reciprocating pumps. A separate sensor coupled to one cylinder of each pump provides an electrical signal each time the piston in that cylinder is at a predetermined position. A speed control circuit is provided to independently adjust the speed of each pump. Manual speed control for each pump is provided through a separate throttle for each pump. A pump control circuit coupled to each of the throttles, sensors and speed control circuit controls the operation of the system. An operator determines which of the pumps to operate by closing appropriate bypass switches provided at the pump control circuit, turns on the first (master) pump and adjusts its associated throttle to operate the pump at a desired speed. The operator then turns on each of the remaining (slave) pumps.

Abstract: Water pumping apparatus is described for use with wells in which on-off cycling in pump operation is minimized by providing an air compressor and compressed air holding tank feeding an pressure regulating valve connected to discharge into a water holding tank, thereby enabling constant pneumatic pressure to be maintained in the water tank without regard to water level in the tank so that each cycling of the water pump will completely fill the water tank from nominally empty condition to nominally full condition.

Abstract: Method of optimizing the operation of two or more compressors in parallel or in series. Known methods of this type assume that the compressors are similar and attempt to optimize their operation by balancing the outputs of or the loads on the individual compressors. Although this approach is satisfactory within its limitations, it cannot be employed with compressors that are dissimilar. The new method is intended to ensure economically optimized operation of two or more similar or dissimilar compressors in parallel or in series. The new method is essentially characterized in that the operating points of each pair of compressors are mutually and incrementally displaced without affecting the total operation parameters. The affect of the displacement on the total constraint is monitored. When the variation is occurring in the direction of optimization, it is continued in the same direction. Otherwise, the pressure that the operating points are displaced in is reversed.

Abstract: A system for metering the volume of a liquid, e.g. ink, supplied by a positive displacement pump to an installation, such as a printing press, employs a device for generating a first series of signals each indicative of completion of a pumping stroke. The speed of the pump is also sensed to generate a second series of signals each indicative of the positive supply of liquid by the pump. The signals of the first series are counted only in the presence of a corresponding signal of the second series. The result is an accurate numerical indication of the total volume of liquid pumped.

Abstract: A system for controlling the output flow rate of a second pump to proportionately track the output flow rate of a first pump in which the first pump produces an electrical signal at each successive stroke thereof. An electrical circuit produces an electrical control signal from the first pump stroke signal for controlling the flow rate of the second pump.

Abstract: A vacuum pump aggregate utilizes a microprocessor in conjunction with pressure and temperature sensors and motor control circuits to regulate the pressure by varying the speed of one or more vacuum pumps. Measured temperature and/or pressure values are compared with predetermined values by the microprocessor which in turn adjusts the speed of the motors.

Abstract: A plurality of relatively large, high capacity, high head, pumps disposed in parallel in the basement of a building provide water under pressure throughout the water pipes in a high rise building. Pressurestatic switch means controls the operation of these main pumps. A small, low capacity, high head auxiliary pump of an auxiliary booster system in the upper regions of the building supplies water to an accumulator tank in the auxiliary system from the water pipes so that during periods of low demand, such as at night and on weekends, the operation of the main pumps will be minimized. A control assembly including a timer and pressurestatic limit switches in the auxiliary control system dictates when the auxiliary pump is actuated and shut off and when the accumulator tank is opened to the water pipes.

Abstract: For use in connection with a water supply system wherein pumping means draws water from a source and supplies it to various consumers by way of a main and branch lines from a main, a supplement to said supply system including a tank forming a first large standpipe for storage of water and a second smaller standpipe. The second standpipe is positioned within said first standpipe to project upwardly from and perpendicular to its bottom to a level approaching but spaced from the top of said first standpipe. A distribution line is provided one end of which opens into the bottom of said first standpipe and the other end of which is arranged to connect to said main. The lower end of said second standpipe, which opens from the bottom of said tank, has coupled thereto one end of a first flow line the opposite end of which is arranged to connect to said main.