Abstract:
Methods and systems are provided to adaptively control a hydraulic fluid supply to supply a driving fluid for applying a driving force on a piston in a gas compressor, the driving force being cyclically reversed between a first direction and a second direction to cause the piston to reciprocate in strokes. During a first stroke of the piston, a speed of the piston, a temperature of the driving fluid, and a load pressure applied to the piston is monitored. Reversal of the driving force after the first stroke is controlled based on the speed, load pressure, and temperature.
Abstract:
A liquid feeding apparatus includes: a plurality of plunger pumps fluidly connected in series or in parallel between a suction flow path and a discharge flow path; and a control unit configured to control an operation of the plunger pump. The control unit includes a compensation flow rate calculation unit configured to calculate a positive compensation flow rate which changes with time in synchronization with the period with respect to a set flow rate. The compensation flow rate is a flow rate which compensates for a loss of the flow rate caused by cooling and contraction in a discharge stroke after the fluid in the plunger pump is compressed and heated in a pre-compression stroke. The compensation flow rate calculation unit is configured to calculate the compensation flow rate.
Abstract:
A linear motor compressor including a compressor housing and a cylinder housing having a plurality of opposing compression chambers. A piston freely reciprocates within the cylinder housing using a linear electric motor. A piston position feedback control system provides adaptive current output as a function of position feedback and/or velocity feedback from the piston and/or the electric motor, to directly power and control the electric motor, wherein the piston reciprocates without assistance from a mechanical spring or other equivalent centering force.
Abstract:
A pumping unit for a machine to distribute concrete includes a pair of cylinders provided with a relative pumping piston movable linearly for a determinate travel to feed the concrete to a determinate circuit to distribute the concrete; and a hydraulic command circuit operatively connected to both the cylinders, to determine an alternate pumping movement of the relative pumping pistons. The pumping unit includes at least a sensor member operatively associated to at least one of the cylinders in order to detect point-by-point one or more data relating to the operating condition of the pumping piston during its movement for the whole travel. The data includes at least one of position, speed, stress and direction of movement of the relative piston.
Abstract:
A method for protecting a resonant linear compressor (14) including structural resonance frequencies (wE) and a motor that is fed by feed voltage (Va) that has amplitude (A) and a drive frequency (wA), both controlled according to the equation A.sin(wt). The protection method is configured so as to include the step of preventing feed to the motor at drive frequencies (wA) that have at least one harmonic coinciding tithe the structural resonance frequency (wE) of the resonant linear compressor (14). A protection system of a resonant linear compressor (14) includes an electronic control (30) configured to prevent feed to the motor at the drive frequencies (wA) that have at least one harmonic coinciding with the structural resonance frequency (wE) of the resonant linear compressor (14).
Abstract:
A metering pump unit with a metering chamber (6), a positive-displacement body that adjoins the latter and can be moved by a positive-displacement drive (22), as well as a controller (30) for actuating the positive-displacement drive (22). The controller (30) is designed to actuate the positive-displacement drive (22) at least in a specific operating state in such a way that a stroke, in particular a pressure stroke, of the positive-displacement body is started at a first, lower stroke rate, and the stroke rate is increased to a second, elevated stroke rate as the pressure stroke (36) continues. A method is provided for controlling the positive-displacement drive (22) of such a metering pump unit.
Abstract:
A linear compressor is provided. The linear compressor includes an electro-magnetic spring and a casing that defines a chamber. A piston is received within the chamber of the casing. The electro-magnetic spring can apply a non-linear force to the piston such that a total spring force applied to the piston during a compression stroke is substantially linear.
Abstract:
One or more techniques and/or systems are disclosed for increasing compressed air efficiency in a pump utilizes an air efficiency device in order to optimize the amount of a compressed air in a pump. The air efficiency device may allow for controlling the operation of the air operated diaphragm pump by reducing the flow of compressed air supplied to the pump as the pump moves between first and second diaphragm positions. A sensor may be used to monitor velocity of the diaphragm assemblies. In turn, full position feedback is possible so that the pump self-adjusts to determine the optimum, or close to optimum, turndown point of the diaphragm assemblies. As such, air savings is achieved by minimizing the amount of required compressed air.
Abstract:
A metering pump unit with a metering chamber (6), a positive-displacement body that adjoins the latter and can be moved by a positive-displacement drive (22), as well as a controller (30) for actuating the positive-displacement drive (22). The controller (30) is designed to actuate the positive-displacement drive (22) at least in a specific operating state in such a way that a stroke, in particular a pressure stroke, of the positive-displacement body is started at a first, lower stroke rate, and the stroke rate is increased to a second, elevated stroke rate as the pressure stroke (36) continues. A method is provided for controlling the positive-displacement drive (22) of such a metering pump unit.
Abstract:
A pumpjack speed control system includes a user interface, a controller and a variable speed drive. The user interface includes a mathematical representation of the pumpjack geometry which permits the conversion of rod speed profiles to crank speed profiles.