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:
A sensorless method and apparatus for detecting piston collisions in a free piston linear compressor motor. The waveform of the back EMF incuded in the motor stator windings is analysed for slope discontinuities and other aberations in a time window centred on the back EMF zero-crossings. Waveform slope artifacts are indicative of piston collisions and cause the motor power to be decremented in response.
Abstract:
A compressor having a sensorless motor and a driving method thereof. The compressor includes a sensorless motor having a rotation shaft connected to a rotator, a piston for performing a compression stroke and an intake stroke between a top dead center and a bottom dead center thereof, and a crank connecting the rotation shaft to the piston. The method includes forcibly aligning the rotator such that the rotator is positioned at a start position in the intake stroke of the piston, and accelerating rotation of the forcibly aligned rotator..
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:
A method for operating a construction-material and/or viscous-material pump for conveying construction material and/or viscous material has the steps of: a) determining a required value of a power or of a size of the motor system, corresponding to the power, for moving the conveying piston, b) setting, on the basis of the required value, a speed value of the motor system in such a manner that a power and/or speed reserve value between an operating point, wherein the operating point is defined by the required value of the power or of the size and the speed value, and a characteristic curve of the motor system, wherein the characteristic curve is defined by maximum values of the power or of the size and speed values, wherein maximum values are different for different speed values at least in sections, is greater than or equal to a reserve limit value.
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.
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.
Abstract:
A compressor having a sensorless motor and a driving method thereof. The compressor includes a sensorless motor having a rotation shaft connected to a rotator, a piston for performing a compression stroke and an intake stroke between a top dead center and a bottom dead center thereof, and a crank connecting the rotation shaft to the piston. The method includes forcibly aligning the rotator such that the rotator is positioned at a start position in the intake stroke of the piston, and accelerating rotation of the forcibly aligned rotator.