Abstract:
A fluid delivery system for delivering a metered dose of fluid from a supply tank (28) to a downstream chamber or vessel (10), comprises a pump apparatus (20) comprising a pump plunger (32) which is operable to perform a pumping stroke under the control of an electromagnetic actuator (36), including a solenoid (36a), to effect delivery of the fluid and a control unit (24) for supplying an input signal (58) to the solenoid (36a) to initiate a current flow to the solenoid (36a) and thereby initiate movement of the pump plunger (32). An electronic device (54) provides an output signal to indicate that movement of the pump plunger has stopped at the end of the pumping stroke, and a timer determines a time difference between the input signal (58) being supplied to the solenoid (36a) and the output signal being output by the electronic device (54). A processor (26) compares the time difference with a predetermined time difference and determines, as a result of the comparison, whether or not the pump plunger (32) has performed a valid pumping stroke in which an intended volume of fluid is displaced and which may therefore be used in a totalized flow calculation.
Abstract:
A free piston gas compressor comprising a cylinder (9), a piston (11) reciprocable within the cylinder (9) and a reciprocating linear electric motor derivably coupled to the piston having at least one excitation winding (1, 2). A measure of the reciprocation time of the piston (11) is obtained, any change in the reciprocation time is detected and the power input to said excitation winding (1, 2) is adjusted in response to any detected change in reciprocation time.
Abstract:
The invention relates to a pumping system (12) for supercritical extraction comprising: inlet means adapted to be connected to a source of supercritical fluid; outlet means adapted to provide the pumped fluid to a pressure vessel (18 and 24A); and pumphead means (300) having a pumping chamber (336) communicating with said inlet means and with said outlet means; a piston (304); an inlet valve means controlling the flow of fluid into said pumping chamber (336) means through said inlet means; an outlet valve means controlling the flow of fluid from said pumping chamber means (336) through said outlet means; an inlet conduit means defining a flow path between said inlet valve and said pump chamber (336); and an outlet conduit means defining a flow path between said pump chamber (336) and said outlet valve means; characterized by an air-cooled thermoelectric-cooled heat exchanger means (386) for cooling both the inlet means and the pumphead means (300).
Abstract:
PROBLEM TO BE SOLVED: To provide a method for driving a compressor starting the compressor without generating overcurrent and easily starting the compressor even if predetermined pressure exists in a motor. SOLUTION: This invention relates to the method for driving the compressor. The method for driving the compressor including a sensor-less motor having a rotary shaft connected to a rotor, a piston executing compression stroke and suction stroke between a top dead center and a bottom dead center, and a crank part connecting the rotary shaft and the piston, includes a forcible alignment stage positioning the rotor at a predetermined start position in the suction stroke of the piston and a stage accelerating rotation of the forcibly aligned rotor. COPYRIGHT: (C)2007,JPO&INPIT
Abstract:
A method for operating a reagent metering system which meters a reagent into an exhaust duct of an internal combustion engine upstream of an SCR catalytic converter, in which, after the metering operation is ended, at least part of the reagent metering system is emptied by back-suction by means of a reciprocating pump. The procedure according to the invention is distinguished in that during the back-suction, a stop determination determines the flight time of a reciprocating piston of the reciprocating pump from a starting time as far as the stop time, in that a comparator compares the flight time determined with a flight time threshold value, and in that the activation power of the reciprocating pump is reduced if the flight time determined is less than the flight time threshold value.
Abstract:
Apparatus for carrying out chromatography, preferably liquid process chromatography, in particular for industrial applications, using in each case at least one positive displacement pump, provided with a drive, for feeding product and eluent (mobile phase) onto at least one separation column, wherein the drive of each positive displacement pump is a highly dynamic drive, which is equipped with an integrated transducer system for capturing the distance/time date, which are convertible into corresponding position-regulated travel commands using connected superordinate movement control/regulation.
Abstract:
A free piston gas compressor comprising a cylinder, a piston reciprocable within the cylinder and a reciprocating linear electric motor derivably coupled to the piston having at least one excitation winding. A measure of the reciprocation time of the piston is obtained, any change in the reciprocation time is detected and the power input to said excitation winding is adjusted in response to any detected change in reciprocation time.