A dryer for a compressed gas provided with a vessel with a drying agent and a drying zone-and a regeneration zone; at least one intermediate zone that, viewed in the direction of rotation of the drum, is situated between the regeneration zone and the drying zone and which is provided with a separate inlet and an outlet that is shared with or connected to the outlet of the regeneration zone; a tap-off pipe that branches off from the outlet of the drying zone and connects to the aforementioned separate inlet of the intermediate zone; one or more blowers in the tap-off pipe for effectuating an intermediate flow from the drying zone, where the dryer is configured such that the entire flow of gas to be dried supplied to the dryer is first guided through the regeneration zone.

A compressor is disclosed which can include a first stage and a second stage. In one form the compressor includes contact cooled compressor stages. The compressor can include a rod useful to inject a lubricant for purposes of cooling/lubricating/sealing the rotating components of the compressor. In one form the rod is an elongate rod with openings which permit a lubricant such as oil to be injected. The injected oil can be atomized via the openings. The rod can be positioned in the interstage space between the first and second stages, and can include a variety of openings.

A compressor is disclosed which can include a first stage and a second stage. In one form the compressor includes contact cooled compressor stages. The compressor can include a rod useful to inject a lubricant for purposes of cooling/lubricating/sealing the rotating components of the compressor. In one form the rod is an elongate rod with openings which permit a lubricant such as oil to be injected. The injected oil can be atomized via the openings. The rod can be positioned in the interstage space between the first and second stages, and can include a variety of openings.

Vacuum pump having a housing which defines a pump chamber and a drive chamber. A rotor is arranged in the housing, wherein the rotor has at least one rotor element arranged in the pump chamber for conveying a gaseous medium from an inlet to an outlet. Therein, the rotor extends from the pump chamber through a shaft feedthrough into the drive chamber. The shaft feedthrough has a connection, wherein the connection is connected to an underpressure, so that a barrier gas flows from the drive chamber at least partially through the shaft feedthrough to the connection.

The invention relates to a method for controlling a rotary screw compressor, having at least a first and a second air-end, wherein both air-ends are driven separately from one another and speed controlled. According to the invention, the following steps are carried out: detection of a volume flow taken at the outlet of the second air-end; adjustment of the rotational speed of both air-ends, when the removed volume flow fluctuates in a range between a maximum value and a minimum value; opening of a pressure-relief valve, if the volume flow falls below the minimum value; and reduction of the rotational speed of at least the first air-end to a predetermined idling speed (V1.sub.L) to reduce the volumetric flow delivered by the first to the second air-end.

A power saving vacuuming pump system is based on complete-bearing-sealing and dry-large-pressure-difference root vacuuming root pumps includes an input valve at an input end of a vacuum space for receiving gas mixture of saturation water vapor and non-condensed air from a condenser of a power plant; a first root vacuum pump connected to the input valve for receiving gas mixture from the input valve and then compressing the gas mixture; a second root vacuum pump connected to the first root vacuum pump for receiving gas mixture from the first root vacuum pump and then compressing the gas mixture. Inner connection walls between the vacuum chamber and the two bearing chambers are installed respective bearings which are installed to be around the driving shaft, and thus all the vacuum chamber and the two bearing chambers are tightly sealed. The vacuum chamber is completely dried so as to prevent from internal emulsion.

The invention relates to a method for controlling a rotary screw compressor, having at least a first and a second air-end, wherein both air-ends are driven separately from one another and speed controlled. According to the invention, the following steps are carried out: detection of a volume flow taken at the outlet of the second air-end; adjustment of the rotational speed of both air-ends, when the removed volume flow fluctuates in a range between a maximum value and a minimum value; opening of a pressure-relief valve, if the volume flow falls below the minimum value; and reduction of the rotational speed of at least the first air-end to a predetermined idling speed (V1.sub.L) to reduce the volumetric flow delivered by the first to the second air-end.

A fluid delivery device has a primary pump and a main pump fluidically connected to the primary pump. The primary pump can be driven by a primary pump input shaft, the main pump can be driven by a main pump input shaft, and the primary pump input shaft and the main pump input shaft are mechanically coupled to a common drive shaft of the fluid delivery device. The primary pump is in the form of a non-compensated gear pump or a centrifugal pump and the main pump is in the form of a compensated internal gear pump.

A screw compressor 2 includes a compressor main body 4, a motor 8, and a gearbox 10. The compressor main body 4 includes screw rotors 5c, 5d, 6c, and 6d, rotor casings 5e and 6e accommodating therein the screw rotors 5c, 5d, 6c, and 6d, and main body casings 5a and 6a accommodating therein the rotor casings 5e and 6e, the main body casings being provided with first flanges 5b and 6b on respective ends thereof. The motor 8 drives the screw rotors 5c, 5d, 6c, and 6d via gears 10f and 10g. The gearbox 10 has an attachment surface Son which the first flange 6b to the main body casings 5a and 6a is attached, accommodates therein the gears 10f and 10g, and has a substantially rectangular shape. In a state where the compressor main body 4 is attached to the gearbox 10, a part of the first flange 6b extends to an outside of the attachment surface S, and projection regions of the rotor casings 5e and 6e onto the attachment surface S exist within the attachment surface S. In this way, vibrations of the screw compressor 2 can be reduced.

A rotary piston compressor (1) for a system for temperature conditioning comprises a rotor (19) mounted in a housing (21), wherein the rotary piston compressor (1) is designed in such a way that the rotor (19) rotates in a first direction in a first operating state and rotates in a second direction opposite to the first direction in a second operating state, and wherein, in the first operating state, a first compressor connection (3) is designed to supply a heat transfer medium (17), and a second compressor connection (5) is designed to discharge the compressed heat transfer medium (17), and wherein, in the second operating state, the second compressor connection (5) is designed to supply the heat transfer medium (17), and the first compressor connection (3) is designed to discharge the compressed heat transfer medium (17).