Liquid ring compressor having a distribution groove for sealing

A liquid-ring compressor having a rotor mounted in a compressor housing. The rotor is mounted eccentrically relative to the center axis of the compressor housing. At least one control disk is arranged on one of the end faces of the rotor. The control disk is provided with a suction slot and a pressure slot for the feed and discharge of the medium to be compressed, respectively. The control disk also has an encircling distribution groove in the area covered radially by the hub of the rotor. Operating liquid is introduced into a feed opening, which leads to the distribution groove, to seal an axial gap between the control disk and the rotor hub. A blocking element projects radially into the distribution groove and is provided on the side of the feed opening that has the greater pressure differential between the pressure of the operating liquid entering the feed opening and the pressure in the rotor cells. The blocking element improves the sealing of the axial gap.

FIELD OF THE INVENTION 
The invention relates generally to liquid ring compressors. In particular, 
the invention relates to liquid ring compressors that have a rotor 
eccentrically mounted in the compressor housing and at least one control 
disk arranged at one end of the rotor. The control disk is provided with a 
suction slot and a pressure slot and a distribution groove. The 
distribution groove is located in the area of the hub of the rotor. A feed 
opening leads to the distribution groove, Operating liquid is introduced 
into the feed opening to seal an axial gap that exists between the control 
disk and the rotor hub. 
BACKGROUND OF THE INVENTION 
Liquid ring compressors are generally described in DE-B-027 358. In this 
compressor, an opening is provided directly after the pressure slot 
relative to the direction of rotation of the rotor. The opening is in 
fluid flow communication with a radial transverse groove formed in the 
control disk. The transverse groove leads into an inner and an outer 
encircling distribution groove. The liquid ring of the compressor covers 
the opening. Operating liquid is directed through the opening, into the 
transverse groove and subsequently into the distribution grooves. The 
operating liquid flows from the distribution grooves into an axial gap 
between the control disk and the rotor hub, thus sealing the axial gap. A 
pressure pattern that increases from the intake pressure to the compressor 
pressure develops across the periphery of the distribution groove. 
Therefore, the pressure difference between the feed pressure of the 
operating liquid and the pressure in the individual rotor cells is not 
constant. This consequently leads to more operating liquid being forced 
through the axial gap in areas of a greater pressure difference than in 
areas where the pressure difference is not so great. Thus, uniform sealing 
of the axial gap is not guaranteed. 
It is an objective of this invention to provide a liquid-ring compressor 
that improves the sealing of the axial gap between the control disk and 
the rotor hub. 
SUMMARY OF THE INVENTION 
The objective is achieved by providing a blocking element that projects 
radially into the distribution groove on the side of the opening that has 
a greater pressure differential between the feed pressure of the operating 
liquid and the pressure in the rotor cells. A blocking element in the 
distribution groove prevents the operating liquid that seals the axial gap 
from flowing directly from the feed opening to the area of the greater 
pressure differential. Instead, by arranging the blocking element on the 
side of the feed opening having the greater differential, the operating 
liquid is directed to the area where the pressure difference between the 
feed pressure of the operating liquid and the pressure in the rotor cells 
is not as great. This arrangement provides a better overall distribution 
of the operating liquid sealing off the axial gap over the full periphery 
of the distribution groove. 
Direct flow from the feed opening to the area of the greater pressure 
differential can be completely prevented if the blocking element extends 
over the full radial extent of the distribution groove. 
Since the distribution groove directly encircles the rotor shaft, the 
radial length of the sealing section is maximized. 
It is especially advantageous that the feed opening be provided in the area 
lying between the end of the suction slot and the start of the pressure 
slot relative to the direction of rotation of the rotor. This arrangement 
directs the flow of the operating liquid in the distribution groove in the 
same direction as the rotation of the rotor so that the operating liquid 
in the distribution groove is still entrained in the peripheral direction 
by the rotating rotor.

DETAILED DESCRIPTION 
FIG. 1 illustrates a liquid ring compressor with compressor housing 1 which 
encloses a working chamber or working space 30. A side plate 20 is 
attached to the end of the housing, thereby delimiting the housing. The 
side plate 20 encloses a suction chamber 21 and a pressure chamber 22. An 
intake connection 2 leads to the suction chamber, and a pressure 
connection 3 connects to the pressure chamber of the side plate 20. Both 
the intake connection 2 and pressure connection 3 are provided on the 
housing 1. A control disk 5 separates the working space 30 containing the 
rotor 4 of the compressor from the suction and pressure chambers 21, 22 of 
the side plate 20. The control disk 5 is attached to the compressor 
housing 1. The rotor lying axially in front of the control disk 5 is 
indicated by broken lines in FIG. 1. The rotor 4 has a plurality of rotor 
cells 4.1 distributed therearound. The axis 6 of the rotor 4 is offset 
eccentrically from the center axis 7 of the compressor housing 1. 
A distribution groove 10 is formed in the control disk 5 and directly 
encircles the shaft 8 of the rotor 4 and opens toward the hub 9 of the 
rotor 4 (see FIG. 2). The distribution groove 10 extends over the full 
periphery of the rotor shaft 8 (subject to the limitations set forth 
below). A feed opening 11 leads into the distribution groove 10. As shown 
in FIG. 2, this feed opening 11 is connected to a side-plate space 12 
filled with operating liquid. Thus, operating liquid can flow into the 
distribution groove 10 through the feed opening 11. As indicated by arrows 
13 in FIG. 2, the operating liquid flows from the distribution groove 10 
through the axial gap 14 between the control disk 5 and the rotor hub 9 
and into the working space 30 of the compressor where it mixes with the 
operating liquid forming the liquid ring in the working space. The 
operating liquid flowing through the axial gap 14 seals the gap. 
As shown in FIG. 1, the feed opening 11 is arranged in the area between the 
end of the suction slot 16 and the start of the pressure slot 17 of the 
control disk 5 relative to the direction of rotation of the rotor 4 as 
shown by rotation arrow 15. The suction slot 16 connects the suction 
chamber with the working chamber; the pressure slot 17 connects the 
pressure chamber with the working chamber. A blocking element 18, 
connected to the control disk 5, is provided on the side of the feed 
opening 11 adjacent to the suction slot 16. The blocking element 18 is 
designed as a finger and projects radially inward into the distribution 
groove 10. The finger 18 extends radially up to the rotor shaft 8 and 
axially over the full depth of the distribution groove 10. The 
distribution groove is thus virtually completely closed on the side 
adjacent to the suction slot 16. The pressure differential between the 
pressure of the operating liquid that enters the feed opening 11 and the 
pressure in the rotor cells rotating past the suction slot 16 is greatest 
on this side. Since the distribution groove 10 is completely cut off by 
the finger 18, the operating liquid flowing through the feed opening 11 
into the distribution groove 10 cannot flow directly to the 
distribution-groove area adjacent to the suction slot 16. Instead, the 
operating liquid must flow through the distribution groove in the 
direction indicated by arrows 19 in FIG. 1. As the operating liquid flows 
along the distribution groove 10, some of the operating liquid also flows 
radially outward through the axial gap 14 and seals the gap. 
Since the pressure differential between the pressure of the operating 
liquid entering the feed opening and the pressure prevailing in the rotor 
cells in the area lying toward the pressure slot 17 is smaller in this 
area(i.e., smaller than the differential with respect to the area lying 
toward the suction slot 16), the liquid quantity flowing off in this area 
via the axial gap 14 is likewise smaller so that an adequate liquid 
quantity for sufficient sealing of the axial gap 14 is available as the 
operating liquid flows in direction 19 around the distribution groove 10.