A cold trap includes a duct, which is for connecting a volume to be evacuated to a vacuum pump, and a cold panel surrounded by the duct. The duct includes an inlet flange at an evacuation target side and an outlet flange at a vacuum pump side. The outlet flange is arranged at a distance from the inlet flange in the extending direction of the duct. The inlet flange has an outer diameter larger than an outer diameter of the outlet flange.

A cold trap includes a duct, which is for connecting a volume to be evacuated to a vacuum pump, and a cold panel surrounded by the duct. The duct includes an inlet flange at an evacuation target side and an outlet flange at a vacuum pump side. The outlet flange is arranged at a distance from the inlet flange in the extending direction of the duct. The inlet flange has an outer diameter larger than an outer diameter of the outlet flange.

An improved compressed air system utilizes one or more base compressors, such as fixed speed drive compressors, to meet the compressed air demands and one or more trim compressors, such as variable speed drive compressors, to meet the variations in the demand. The operation of both the base and trim compressors may be controlled to provide improved overall efficiency while meeting the transient load demands. The control may spread the demands over the various base compressors to improve the overall loading on each base compressor. Efficiency metrics may be utilized to control the switching between base and trim compressors. Unloading of a base compressor may be controlled to avoid undesirable changes in system performance.

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).

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).

There are provided an operation number control device and a method for controlling the same that can level the operation times of the fluid machines, which are connected to the operation number control device. A fluid machine system comprises a plurality of fluid machines, and an operation number control device capable of individually controlling start and stop of the fluid machines. The operation number control device sets a continuous operation time for each of the fluid machines based on total operation times of the fluid machine and other fluid machines. When among fluid machines in operation, there is a fluid machine for which the continuous operation time set for the fluid machine has elapsed and there is a fluid machine at stop, the operation number control device causes the fluid machine at stop to start and causes the fluid machine to stop.

A leak detector for checking the sealing tightness of an object to be tested includes a detection inlet to be connected to the object, a first pumping device, and a gas detector. The first pumping device includes a first rough vacuum pump, at least one second rough vacuum pump, and a turbomolecular pump. The gas detector is connected to the turbomolecular pump. The outlet of the at least one second rough vacuum pump is connected to the first rough vacuum pump, between two in-series pumping stages of the first rough vacuum pump.

A leak detector for checking the sealing tightness of an object to be tested includes a detection inlet to be connected to the object, a first pumping device, and a gas detector. The first pumping device includes a first rough vacuum pump, at least one second rough vacuum pump, and a turbomolecular pump. The gas detector is connected to the turbomolecular pump. The outlet of the at least one second rough vacuum pump is connected to the first rough vacuum pump, between two in-series pumping stages of the first rough vacuum pump.

An ejector-type refrigeration cycle includes an ejector module integrated with a gas-liquid separation device. A length of an inlet pipe that connects a liquid-phase refrigerant outflow port of an ejector module to a refrigerant inflow port of an evaporator is shorter than a length of a suction pipe that connects a gas-phase refrigerant outflow port of the ejector module to a suction port of the compressor.

A piping structure includes a plurality of pipes that connects a plurality of process modules disposed adjacent to each other at a first room and a plurality of vacuum pumps disposed at a second room below the first room to be corresponding to the plurality of process modules, respectively. The plurality of pipes are divided into a plurality of blocks in a height direction, and the plurality of pipes used for blocks in an identical height have an identical shape.