The present invention relates to a pumping system to generate a vacuum (SP), comprising a main vacuum pump which is a dry screw pump (3) having a gas suction inlet (2) connected to a vacuum chamber (1) and a gas discharge outlet (4) leading into a gas evacuation conduit (5) in the direction of a gas exhaust outlet (8) outside the pumping system. The pumping system comprises a non-return valve (6) positioned between the gas discharge outlet (4) and the gas exhaust outlet (8), and an auxiliary vacuum pump (7) connected in parallel to the non-return valve. In a pumping method by means of this pumping system (SP), the main vacuum pump (3) is started up in order to pump the gases contained in the vacuum chamber (1) and to discharge these gases through its gas discharge outlet (4), simultaneously to which the auxiliary vacuum pump (7) is started up. Moreover the auxiliary vacuum pump (7) continues to pump all the while that the main vacuum pump (3) pumps the gases contained in the vacuum chamber (1) and/or all the while that the main vacuum pump (3) maintains a defined pressure in the vacuum chamber (1).

A mass spectrometer or ion mobility spectrometer is disclosed comprising means for detecting a blockage in an inlet orifice arranged between an ion source and a vacuum chamber. The blockage is detected as a result of a reduction in pressure within the vacuum chamber. This change in pressure is detected indirectly by monitoring the amount of power that a vacuum pump is using, the amount of current that a vacuum pump is drawing, the temperature of a vacuum pump or a region in proximity to the vacuum pump, or the flow rate of gas out of a vacuum pump.

A mass spectrometer or ion mobility spectrometer is disclosed comprising means for detecting a blockage in an inlet orifice arranged between an ion source and a vacuum chamber. The blockage is detected as a result of a reduction in pressure within the vacuum chamber. This change in pressure is detected indirectly by monitoring the amount of power that a vacuum pump is using, the amount of current that a vacuum pump is drawing, the temperature of a vacuum pump or a region in proximity to the vacuum pump, or the flow rate of gas out of a vacuum pump.

A method for controlling a compressor system comprising a plurality of compressors, wherein the compressor system is intended to maintain a predefined excess pressure in a pressurized fluid system, wherein decisions are met at fixed or variable intervals as to switching operations for adapting the system to current conditions, wherein —in a pre-selecting step, switching alternatives are excluded from the plurality of combinatorially available switching alternatives, —in a main selecting step, remaining switching alternatives are weighed against one another while referring to one or more optimization criterion (criteria) and optimum switching alternatives are selected from among the given criteria, and —in a control step, the selected switching alternative is output for implementation in the compressor system.

A method for controlling a compressor system comprising a plurality of compressors, wherein the compressor system is intended to maintain a predefined excess pressure in a pressurized fluid system, wherein decisions are met at fixed or variable intervals as to switching operations for adapting the system to current conditions, wherein —in a pre-selecting step, switching alternatives are excluded from the plurality of combinatorially available switching alternatives, —in a main selecting step, remaining switching alternatives are weighed against one another while referring to one or more optimization criterion (criteria) and optimum switching alternatives are selected from among the given criteria, and —in a control step, the selected switching alternative is output for implementation in the compressor system.

The present invention relates to a pumping system to generate a vacuum (SP), comprising a main vacuum pump which is a claw pump (3) having a gas suction inlet (2) connected to a vacuum chamber (1) and a gas discharge outlet (4) leading into a gas evacuation conduit (5) in the direction of a gas exhaust outlet (8) outside the pumping system. The pumping system comprises a non-return valve (6) positioned between the gas discharge outlet (4) and the gas exhaust outlet (8), and an auxiliary vacuum pump (7) connected in parallel to the non-return valve. In a pumping method by means of this pumping system (SP), the main vacuum pump (3) is started up in order to pump the gases contained in the vacuum chamber (1) and to discharge these gases through its gas discharge outlet (4), simultaneously to which the auxiliary vacuum pump (7) is started up. Moreover the auxiliary vacuum pump (7) continues to pump all the while that the main vacuum pump (3) pumps the gases contained in the vacuum chamber (1) and/or all the while that the main vacuum pump (3) maintains a defined pressure in the vacuum chamber (1).

A system includes a plurality of compressors, an evaporator, an expansion device, and a system controller. The compressors may be linked in parallel. The system controller may: determine a saturated evaporator temperature, a saturated condensing temperature, and a target capacity demand; determine an estimated system capacity and an estimated power consumption for each compressor operating configuration; compare the estimated system capacity with the target capacity demand and an error tolerance value; select an optimum operating mode based on the comparisons and based on the estimated power consumption; and command activation and deactivation of the plurality of compressors to achieve the selected optimum operating mode. The optimum operating mode may be selected after the normal system logic achieves a steady state and may be selected from a group having the estimated system capacity within the error tolerance of the target capacity demand and a lowest associated power consumption value.

A system includes a plurality of compressors, an evaporator, an expansion device, and a system controller. The compressors may be linked in parallel. The system controller may: determine a saturated evaporator temperature, a saturated condensing temperature, and a target capacity demand; determine an estimated system capacity and an estimated power consumption for each compressor operating configuration; compare the estimated system capacity with the target capacity demand and an error tolerance value; select an optimum operating mode based on the comparisons and based on the estimated power consumption; and command activation and deactivation of the plurality of compressors to achieve the selected optimum operating mode. The optimum operating mode may be selected after the normal system logic achieves a steady state and may be selected from a group having the estimated system capacity within the error tolerance of the target capacity demand and a lowest associated power consumption value.

A multistage compression system uses refrigerant and oil. The multistage compression system includes a low-stage compressor that compresses the refrigerant, a high-stage compressor that further compresses the refrigerant compressed by the low-stage compressor, refrigerant pipes that-introduce the refrigerant compressed and discharged by the low-stage compressor into a suction part of the high-stage compressor, a pressure reducing element disposed between the refrigerant pipes, an accumulator disposed between the refrigerant pipes at a downstream side of the pressure reducing element and at an upstream side of the high-stage compressor, and an oil discharge pipe. The oil discharge pipe discharges the oil in the low-stage compressor. The oil discharge pipe connects the low-stage compressor and a portion of the refrigerant pipes. The portion of the refrigerant pipes is on a downstream side of the pressure reducing element and an upstream side of the accumulator.

In order to prevent excessive motor loading or system overheating due to the accumulation of particulate or dust, from SACVD type CVD processes, in the running clearances of the vacuum pump a vacuum pumping arrangement is provided having a plurality of vacuum pumping stages and comprising a first pump inlet through which process fluid from the vacuum chamber can enter the pump and pass through each of the pumping sections towards a pump outlet, and a second pump inlet through which process fluid can enter the pump and pass through only one or more pumping stages downstream of the most upstream pumping stage, wherein the apparatus configured to conveying process fluid from the vacuum chamber to the first pump inlet for pumping during the second processing step and conveying process fluid from the vacuum chamber to the second pump inlet for pumping during the first processing step.