A leak detector is provided for leak-testing objects that are to be tested by spraying tracer gas, the leak detector including: a detection inlet configured to be connected to an object that is to be tested; a pumping device including a vacuum line connected to the detection inlet, a rough-vacuum pump connected to the vacuum line, and a turbomolecular vacuum pump connected to the vacuum line, a delivery of which is connected to the rough-vacuum pump; and a gas detector connected to the turbomolecular vacuum pump, the pumping device further including an ancillary pump connected to the rough-vacuum pump and being configured to lower an ultimate-vacuum pressure of tracer gas in the rough-vacuum pump. A leak detection method for leak-testing objects that are to be tested by spraying tracer gas is also provided.

A dry-type primary vacuum pump includes an injection device to distribute a purging gas in the pumping stages. The injection device includes: a first pressure sensor arranged on a common portion of the distributor, a second pressure sensor arranged on each branch of the distributor, and a control unit to generate a pulse width modulation command signal for the control of the regulation valves independently of one another as a function of the pressure measurement differences between the first pressure sensor and the second pressure sensors.

A dry type primary vacuum pump is provided, including at least two pumping stages mounted in series between a suction and a discharge of the pump; two rotors extending in the pumping stages and being configured to rotate synchronously in a reverse direction to drive a gas to be pumped between the suction and the discharge; an injection device configured to distribute a purge gas in at least one pumping stage, the injection device including at least one injector and at least one injection valve with an on or off control configured to be interposed between a purge gas supply source and the injector; and a control device configured to control opening and closing of the injection valve to inject a purge gas by successive pulses into the at least one pumping stage. A method for controlling the injection of a purge gas the vacuum pump is also provided.

A shunt-enhanced decompression and pulsation trap (SEDAPT) for a screw compressor assists internal compression (IC), reduces gas pulsation and NVH (Noise, Vibration & Harshness), and improves off-design efficiency, without using a slide valve and/or a serial pulsation dampener. The SEDAPT includes an inner casing, e.g., an integral part of the compressor chamber, and an outer casing, e.g., surrounding part of the inner casing near the compressor discharge port, forming at least one diffusing chamber with an outflow orifice or nozzle equipped with an ODV (one-direction valve) at the outflow exit and a feedback region that provides a feedback outflow loop between the compressor chamber and the compressor discharge port. The SEDAPT automatically bleeds or compensates cavity pressure to meet different outlet pressures, eliminates or reduces energy waste, gas pulsations and NVH associated with any over-compression and under-compression before the discharge port opens.

The present invention relates to an arrangement for detecting a delivery volume and/or a delivery flow, with a discontinuously operating pump (1), at least one outlet line (3) and/or one inlet line (2, 2-1, 2-2) and a passive valve (5, 5-1, 5-2), which is arranged in the outlet line (3) or the inlet line (2, 2-1, 2-2) and which has a valve seat (15-1, 15-2) and a valve head (16-1, 16-2), the valve (5, 5-1, 5-2) being closed in a first position of the valve head (16-1, 16-2) and being open in a second position of the valve head (16-1, 16-2) of the valve (5, 5-1, 5-2). The arrangement according to the invention is defined by a sensor (8, 8-1, 8-2), by means of which values can be detected which indicate whether the valve head (16-1, 16-2) is in the first or the second position, and by a computing unit (9) which is coupled to the sensor (8, 8-1, 8-2) and by means of which the volume delivered by the pump (1) and/or the delivery flow of the pump (1) can be calculated on the basis of the detected values of the sensor (8, 8-1, 8-2). The invention relates furthermore, to an extraction system for a plant protective with such an arrangement and to a method for detecting a delivery volume and/or a delivery flow of a discontinuously operating pump, which method can be carried out by this arrangement.

The present disclosure relates to a control circuit for a variable displacement pump in a vehicle transmission, including: a regulator valve configured to regulate displacement control fluid to the variable displacement pump; and a response limiter in communication with the regulator valve, configured to mitigate pressure oscillations in the control circuit.

The application relates to a compressed air station comprising at least two compressed air components that yield waste heat, wherein each compressed air component is designed either as a compressor, in particular as a screw compressor, or as a refrigeration dryer, wherein at least one of the compressed air components, namely a refrigeration dryer (12), is connected to the exhaust air duct (13), and wherein a further compressed air component is connected to the same exhaust air duct (13), wherein a compressed air refrigeration heat exchanger (23) is provided within the refrigeration dryer (12), in which the compressed air is cooled by way of a refrigerant conducted in a refrigerant circuit (24), wherein the refrigerant circuit (24) comprises a refrigerant compressor (25), a condenser (26), an expansion valve (27) and the compressed air refrigeration heat exchanger (23), wherein the compressed air station further comprises a dryer exhaust air duct (15), which is provided for discharging a cooling air flow that is conducted through the refrigeration dryer (12), and which connects a cooling air outlet (19) of the refrigeration dryer (12) to a refrigeration dryer connection (16) on the exhaust air duct (13), wherein the refrigeration dryer (12) has a fan (20) with a speed-adjustable fan motor (21), and the fan (20) is designed to convey the cooling air flow even against a backpressure currently prevailing in the exhaust air duct (13), wherein the refrigeration dryer (12) has a flow sensor (30) for detecting a respective current value for the cooling air volume flow V.sub.act, and wherein the refrigeration dryer (12) has a controller (22) or interacts with a controller (22), which is configured and designed to record and process the data from the flow sensor (30) and to actuate the fan motor (21) of the fan (20) in such a way that, regardless of the current backpressure in the exhaust air duct (13), the respective current cooling air volume flow V.sub.act follows a setpoint for the cooling air volume flow V.sub.soll.

A compressor includes a housing, in which a compression chamber is provided; an injection pipeline installed in the housing and configured to inject a fluid into the compression chamber; and a solenoid valve installed on the injection pipeline in the housing and configured to allow or block off the injection of the fluid through the injection pipeline.

A dry-type primary vacuum pump includes an injection device to distribute a purging gas in the pumping stages. The injection device includes: a first pressure sensor arranged on a common portion of the distributor, a second pressure sensor arranged on each branch of the distributor, and a control unit to generate a pulse width modulation command signal for the control of the regulation valves independently of one another as a function of the pressure measurement differences between the first pressure sensor and the second pressure sensors.

A shunt-enhanced decompression and pulsation trap (SEDAPT) for a screw compressor assists internal compression (IC), reduces gas pulsation and NVH (Noise, Vibration & Harshness), and improves off-design efficiency, without using a slide valve and/or a serial pulsation dampener. The SEDAPT includes an inner casing, e.g., an integral part of the compressor chamber, and an outer casing, e.g., surrounding part of the inner casing near the compressor discharge port, forming at least one diffusing chamber with an outflow orifice or nozzle equipped with an ODV (one-direction valve) at the outflow exit and a feedback region that provides a feedback outflow loop between the compressor chamber and the compressor discharge port. The SEDAPT automatically bleeds or compensates cavity pressure to meet different outlet pressures, eliminates or reduces energy waste, gas pulsations and NVH associated with any over-compression and under-compression before the discharge port opens.