WO2002077461A1 - Water-injected volumetric compressor - Google Patents

Abstract

The invention relates to a water-injected volumetric compressor comprising a compressor element (1), a pressure conduit (3) in which a vessel (4) is situated which at the same time is a water separator, a return conduit (5) for the water between the vessel (4) and the compressor element (1), and a water filter (6) in this return conduit (5), whereby the water filter (6) is situated in the vessel (4).

Description

Water-injected volumetric compressor.

This invention relates to a water-injected volumetric compressor.

Such compressors have a compressor element, into which water is injected for lubrication and cooling. This water then is separated from the compressed gas, mostly air, into a vessel, and the separated water then flows, through a return conduit, back to the compressor element. The vessel serves as a buffer receptacle in order to have a sufficient quantity of water available.

As the water, separated from the compressed gas, may comprise impurities, the water, while being fed back, is filtered in a water filter which is provided in the return conduit.

Analogous to the oil-injected compressors, in which the oil filter is installed in the return conduit in a separate housing outside of the vessel, in the known water-injected compressors this water filter also is installed in a separate housing outside of the vessel.

Due to corrosion problems with water, this housing is made in stainless steel or synthetic material. The housings made of synthetic material, even reinforced with fibers, are not in a guaranteed manner at the same time resistant against the high working pressures and high temperatures. Stainless steel housings have the disadvantage of being very expensive.

The present invention aims at offering a remedy for the above-mentioned disadvantages and at providing a compressor with a relatively inexpensive water filter. To this aim, the invention consists of a water-injected volumetric compressor comprising a compressor element, a pressure conduit in which a vessel is situated which at the same time is a water separator, a return conduit for the water between the vessel and the compressor element, and a water filter in this return conduit, which is characterized in that the water filter is situated in the vessel .

This vessel, of course, is resistant against the operation conditions, to wit pressures and temperatures, of the compressed gas and, therefore, of the water. Moreover, this vessel, as it also serves as a buffer receptacle for the compressed gas, is large enough for housing a water filter therein.

Preferably, said water filter is situated in the vessel, in the bottom part thereof, such that, during normal operation, it is immersed in water. The water filter then does not need a housing, such that the mentioned disadvantages are no longer valid.

With the intention of better showing the characteristics of the invention, hereafter, as an example without any limitative character, a preferred form of embodiment of a water-injected volumetric compressor according to the invention is described, with reference to the accompanying drawing, which schematically shows such compressor.

The water-injected volumetric compressor represented in the figure comprises a compressor element 1, a motor 2 connected thereto for driving it, a pressure conduit 3 in which a vessel 4 is situated, which at the same time is a water separator, a return conduit 5 between the vessel 4 and the compressor element 1, and in this return conduit 5 a water filter 6 which, however, is situated at the beginning of this return conduit and inside the vessel, in the bottom part thereof.

The compressor element 1 has an inlet 7 for the gas to be compressed and an outlet 8 for the compressed gas. To this outlet 8, the pressure conduit 3 is connected. An inlet conduit 9 is connected to the inlet 7.

When the motor 2 drives the compressor element 1, through the inlet 7 gas, mostly air, is suctioned which is compressed in the compressor element 1 and subsequently, through the outlet 8 and the pressure conduit 3 , gets into the vessel 4.

There, the water is separated from the gas and fed over the water filter 6 and through the return conduit 5 back to the compressor element 1, where it is injected for lubricating, cooling and sealing the rotors of the compressor element 1.

As the water filter 6 is situated in the vessel 4, in or beneath the water, it is not necessary to provide it with a housing, and it can be restricted to a filter cartridge.

The water filter 6 may be situated entirely below the water level.

In the cases in which the water filter 6, due to the required filter surface or to the whirling of the water in the vessel 4, protrudes from the water level, it is necessary to place a cap over the upper side of the filter, which cap reaches up to under the water level, in order to prevent that gas, for example, air, will get through this water filter 6 into the return conduit 5. If the water filter 6 comprises a housing, then a closed part of the housing can form this cap.

The water filter 6 or the filter cartridge thereof must be replaced from time to time. Of course, the vessel 4 to this end must be provided, with an access.

When the water filter 6, such as in the represented example, is situated in or under the water, this means that during such replacement, the water flows out of the bottom side of the vessel 4, if it had not been removed. This does not pose any problems, as the water simply can be drained and afterwards can be replaced by fresh water.

With the intention of separating the water, the mixture of compressed gas and water is fed tangentially into the vessel 4, mostly along an inner partition 10 in the vessel. Without a water filter 6, this air causes a vortex in the water accumulating at the bottom of the vessel 4 , as a result of which air is taken up in the water. It was noted that the water filter 6 breaks this vortex, such that less air is taken up in the water.

The water-injected volumetric compressor according to the invention may be a screw-type compressor, but may also be another type of volumetric compressor.

The present invention is in no way limited to the form of embodiment described as an example and represented in the figure, however, such water-injected volumetric compressor may be realized in different forms and dimensions, without leaving the scope of the invention.'

Claims

Claims.

1.- Water-injected volumetric compressor comprising a compressor element (1) , a pressure conduit ( 3) in which a vessel (4) is situated which at the same time is a water separator, a return conduit (5) for the water between the vessel (4) and the compressor element (1), and a water filter (6) in this return conduit (5), characterized in that the water filter (6) is situated in the vessel (4).

2.- Water-injected volumetric compressor according to claim 1, characterized in that the water filter (6) is situated in the vessel (4), in the bottom part thereof.

3.- Water-injected volumetric compressor according to claim 2, characterized in that the water filter (6) is free of a housing.

4. - Water-injected volumetric compressor according to claim 2 or 3, characterized in that it is situated entirely below the water level in the vessel (4) .

5.- Water-injected volumetric compressor according to claim 2, characterized in that it protrudes with a part above the water level and is provided with a cap which reaches up to below said water level.

Water-injected volumetric compressor,

The invention relates to a water-injected volumetric compressor comprising a compressor element (1), a pressure conduit (3) in which a vessel (4) is situated which at the same time is a water separator, a return conduit (5) for the water between the vessel (4) and the compressor element (1), and a water filter (6) in this return conduit (5), whereby the water filter (6) is situated in the vessel (4).

Sole figure.