Abstract: A device evacuates a chamber and purifies the gas extracted from said chamber of any foreign substances. The device comprises a dry-condensing vacuum pump having an input connected to the chamber to be evacuated and is suitable for maintaining the input pressure at a constant level at the output despite variable conditions. An intermediate line which connects to the output of the dry-condensing vacuum pump and a liquid ring vacuum pump, the input of which is connected to the intermediate line, are additionally provided. A corresponding method makes it possible to purify the gas of any foreign substances reliably and effectively.

Abstract: A method for evacuating a chamber employs a pump arrangement composed of a booster pump and of a downstream forepump is connected to the chamber. The booster pump is accelerated, gas from the chamber is introduced into the booster pump, such that from the booster pump there is temporarily extracted an excess power which exceeds the power provided by the drive of the booster pump. The gas is discharged through a bypass valve while the outlet pressure of the booster pump lies above a predefined threshold value, and the gas is directed to the forepump when the outlet pressure of the booster pump has fallen below the threshold value. The gas supplied by the booster pump is compressed by means of the forepump.

Abstract: A side-channel pump having a pump housing in which an operating chamber which is provided with a side channel and a motor are arranged, and having an impeller in the operating chamber which rotates with a shaft which is driven by the motor. A cooling circuit extends from the operating chamber to the motor and from the motor to a suction portion of the pump, wherein the cooling circuit is supplied from an operating chamber whose outlet side is connected to an outlet opening of the side-channel pump. Using the pump, gas can be drawn in without the pump becoming overheated.

Abstract: A fluid ring compressor comprises a first single-acting compression stage having a first impeller eccentrically mounted in a housing and a second single-acting compression stage having a second impeller eccentrically mounted in a housing. The first compression stage and the second compression stage are separated from one another by a sealing gap. The sealing gap is arranged between a suction section of the first compression stage and a suction section of the second compression stage.

Abstract: The invention relates to an assembly comprising a vacuum pump and a chamber, wherein a suction tract extends between the chamber and the vacuum pump. The vacuum pump is a liquid ring machine. According to the invention, a liquid outlet is arranged in the suction tract in order to add liquid to gas sucked in from the chamber. The invention further relates to a method for evacuating a chamber filled with vapor. According to the invention, the vapor is condensed by introducing additional liquid into the suction tract, thus by co-condensation. By supplying liquid selectively only when liquid is required for the condensation of the vapor, water is saved.

Abstract: A liquid-ring vacuum pump comprises a pump casing and a shaft eccentrically mounted in the pump casing. An impeller and a rotor of a drive motor are connected to the shaft. A disk cam is arranged parallel to the impeller. A first main bearing for the shaft is arranged between the impeller and the rotor of the drive motor, on the plane of the disk cam. The impeller is arranged between the first main bearing and a second main bearing. The arrangement of the bearings prevents the shaft from bending, thus allowing the leakage gap between the impeller and the disk cam to be kept small.

Abstract: The invention relates to a screw pump having two screws, in which screw pump each screw has a first thread and a second thread. The threads extend in each case from a suction side to a delivery side. The threads are in engagement with one another, with the result that the threads are divided into a plurality of working chambers, the volume of which decreases from the suction side to the delivery side. According to the invention, the threads have two thread turns. Moreover, the invention relates to a screw for a pump of this type. On account of the uniform distribution of mass of the two-turn threads, the pump can be operated at a high rotational speed, with the result that the throughput of the pump is increased.

Abstract: The invention relates to a side-channel pump and to a method for operating a side-channel pump in which an impeller rotates in a working chamber provided with a side channel. According to the invention, the pump is operated at an overspeed with a gas-filled working chamber in a first step. The speed is then reduced to an operating speed in order to pump a liquid. The pump according to the invention has a high suction power as a result of the overspeed, but only gas is drawn initially.

Abstract: A method for operating a liquid ring vacuum pump employs taking vibration measurements of the pump and comparing the measurements with a prescribed cavitation threshold. In addition, a measurement representing the liquid content in the gas to be conveyed is taken. This measurement is compared with a prescribed threshold. The rotational speed of the liquid ring vacuum pump is reduced if the prescribed cavitation threshold has been exceeded and the liquid content is less than the prescribed threshold. The rotational speed is increased if the prescribed cavitation threshold has been exceeded and the liquid content is greater than the prescribed threshold. A liquid ring vacuum pump is designed for implementing the method. Due to the regulation depending on the oscillations of the pump, the pump can be operated near the cavitation boundary without any risk of damage.

Abstract: The apparatus for monitoring appliances and machines having rotating components, particularly for monitoring compressors, vacuum pumps and other pumps, has a sensor, an evaluation electronics unit and an interface for the output of signals. The evaluation electronics unit has a microprocessor having three inputs for performing measurements in three different frequency ranges at different frequency resolutions, with the respective vibration intensities being averaged at a plurality of frequencies in line with the third-octave spectrum. The interface is a two-wire interface which is used to report different operating states using different DC values.