[0001] This invention relates to a compressor with at least one compressor stage and a moisture
separator, whereby the compressor stage comprises a housing which is provided with
an inlet for gas to be compressed and an outlet and comprises at least two cooperating
compressor elements mounted in this housing, whereby at least one of which is rotatable.
[0002] In a multi-stage compressor, the gas compressed by a compressor stage, which is heated
by this compression, is cooled in an intermediate cooler. During this cooling, the
moisture present in this gas is condensed in the form of humidity particles which
are carried along with the gas to the subsequent compressor stage.
[0003] In order to prevent that these moisture particles get into the subsequent compressor
stage, in the known compressors mostly a moisture separator is placed between the
intermediate cooler and the subsequent compressor stage.
[0004] These separate moisture separators, however, take a lot of space, are relatively
expensive and have a limited separation capacity.
[0005] Also for the first compressor stage or in a one-stage compressor, if moisture might
be present in the gas to be compressed, a moisture separator is placed before this
stage.
[0006] This invention aims at a compressor which excludes the aforementioned and other disadvantages
and which, in a constructionally simple, compact and relatively cheap manner, makes
it possible in a practical manner to separate moisture from the gas to be compressed.
[0007] According to the invention, this aim is achieved in that the inlet of the compressor
stage is almost closed off by a rapidly rotating body made of material having a sufficiently
low flow resistance for the gas in order to let the gas pass, but which keeps back
moisture particles and other particles and whirls them radially away, which body is
integrated in the housing.
[0008] Such bodies are already used for the separation of water from an air stream, however,
in separate separators.
[0009] The body may be driven by the gas stream itself or by an external power source, but
preferably, the inlet extends over a shaft with which the rotatable compressor element
is beared in the housing, and the body is fixed on this shaft.
[0010] At the height of this body, the inlet may be provided with an enlargement forming
a chamber wherein the whirled-away moisture is collected.
[0011] This body may consist of cellular material with open cells or may be formed by a
brush.
[0012] With the intention of better showing the characteristics of the invention, hereafter,
by way of example without any limitative character, a preferred form of embodiment
of a compressor with at least one compressor stage and a moisture separator according
to the invention is described, with reference to the accompanying drawings, wherein:
figure 1 schematically represents a cross-section of one stage of a compressor according
to the invention;
figure 2 represents the section which is indicated by F2 in figure 1, but in respect
to another form of embodiment;
figure 3 represents the section from figure 2, but in respect to still another form
of embodiment.
[0013] In figure 1, a compressor stage of a screw compressor is represented which substantially
consists of a housing 1 in which two cooperating compressor elements 2 and 3, formed
by screw-shaped rotors, are mounted in a rotatable manner.
[0014] Due to constructive purposes, the housing 1 consists of various parts which are fixed
to each other, for example, by means of bolts.
[0015] The housing 1 determines an innermost space 4 in which the rotatable compressor elements
2 and 3 are situated.
[0016] The rotatable compressor element 2 consists of a screw-shaped body 5 which, at both
extremities, is axially provided with a shaft 6, 7 respectively.
[0017] The shaft 6 is beared in a bearing 8 mounted in the housing 1 and connects directly
or by the intermediary of a transmission to a drive motor, not represented in figure
1.
[0018] The shaft 7 is beared in a ball-bearing 9 integrated in the housing 1. At the outside
of this ball-bearing 9, a ring 10 is clamped onto the shaft 7.
[0019] In an analogous manner, the rotatable compressor element 1 comprises a screw-shaped
body 11 and, at both extremities thereof, a shaft 12, 13 respectively.
[0020] At one side, the shaft 12 is beared in a ball-bearing 14 which is fixed in the housing
1. At the outside of this ball-bearing 14, a clamping ring 10 is also clamped onto
the shaft 12.
[0021] At the other side, the shaft 13 is beared in a bearing 15 which is also integrated
in the housing 1.
[0022] This shaft 13 extends with a prolonged extremity 13A beyond the bearing 15, namely
up into a chamber 16 which is formed in an end wall of the housing 1 and forms part
of the inlet 16-17-18 which, thus, extends over the shaft 13.
[0023] The part 17 of the inlet connects the chamber 16 to the low-pressure side of the
space 4, whereas the part 18 of the inlet, which has a smaller cross-section than
the chamber 16, connects this chamber 16 to the exterior of the housing 1.
[0024] In the chamber 16, a body 19 in the form of a round disc is fixed at the prolonged
extremity 13A of the shaft 13, which body is manufactured of cellular material with
open cells.
[0025] The diameter of the body 19 is smaller than the diameter of the chamber 16, but larger
than the diameter of the part 18 of the inlet 16-17-18 which, anyhow, is closed off
almost completely by the body 19.
[0026] The body 19 has a sufficiently low flow resistance in order to let the gas to be
compressed, in particular air, pass.
[0027] In the form of embodiment represented in figure 1, this body 19 consists of a hard
foam made of synthetic material, of metal or of ceramic material.
[0028] A very suitable material for the body 19 is a foam made of metal which is manufactured
by depositing a metal layer, for example nickel or nickel-chromium, by means of a
galvanic procedure on a polyurethane foam and subsequently removing this polyurethane
foam by pyrolysis, or a foam made of ceramic material which is manufactured by the
deposition of a ceramic material on a polyurethane foam and the subsequent thermic
removal of this polyurethane foam, for example, by pyrolysis.
[0029] A discharge channel 20 which extends up to outward the housing 1, is connected to
the chamber 16.
[0030] An outlet 21 for the compressed gas extends through the housing 1, at the side opposed
to the inlet 16-17-18.
[0031] The working of the compressor is simple and as follows.
[0032] Due to the actuation, by means of the shaft 6, the body 5 is rotated which, in its
turn, rotates the body 11 by means of gearwheels or by direct contact.
[0033] The gas to be compressed, which possibly is already coming from a preceding compressor
stage, is brought through the inlet 16-17-18 into the chamber 4 and compressed by
means of the compressor elements 2 and 3. The compressed gas is discharged through
outlet 21.
[0034] Thereby, this gas to be compressed flows through the rotating body 19 which is completely
integrated in the housing 1, where the moisture particles are kept back and whirled
radially out of the body 19.
[0035] The flow direction of the gas to be compressed is indicated by arrows 22.
[0036] Said moisture particles are collected at the bottom in the chamber 16, which is indicated
by arrows 23, and discharged by the discharge channel 20.
[0037] The compressor described heretofore, thus, does not need a separate moisture separator.
The body 19 forms a moisture separator integrated in the compressor stage, as a result
of which the whole unit is compact and relatively cheap.
[0038] Instead of being mounted on the shaft 13 of the compressor element 3, the body 19
may be mounted on the shaft 6 of the compressor element 2, in which case the inlet
has to extend over this shaft 6.
[0039] The compressor, a part of which is represented in figure 2, differs from the one
represented in figure 1 in that means are provided to direct the flow of the gas to
be compressed in the body 19 substantially in the transverse direction towards the
shaft 13.
[0040] Said means are formed by a ring-shaped plate 24 which covers the side of the body
19 directed towards the part 18 of the inlet 16-17-18 and is fixed against this body,
for example, glued, and by a second ring-shaped plate 25 which is fixed against the
opposite side of the body 19 but which solely covers the exterior part of this side.
[0041] The gas to be compressed flows through the chamber 16 and along the exterior edge
of the body 19 into this body 19 and leaves this body next to the shaft 13, after
separating the liquid particles which are radially whirled outside.
[0042] The form of embodiment represented in figure 3 differs from the form of embodiment
according to figure 1 by a different construction of the body 19 which, instead of
a disc made of foam, is a round and, for example, disc-shaped brush.
[0043] This brush preferably comprises steel bristles 26 which are directed almost radially
and are fixed to a core 27, sitting, for example, clamped in a U-shaped groove. This
core 27 is fixed, for example, glued, clamped of screwed on the prolonged extremity
13A of the shaft 13.
[0044] The brush also lets the gas to be compressed pass, but keeps back moisture particles
which, during rotation of the shaft 13 and, therefore, also of the brush, are whirled
away radially and are collected in the chamber 16.
[0045] The invention is not limited to screw compressors, but also applicable in other compressors,
preferably with at least one rotatable compressor element upon which the body can
be mounted.
[0046] The present invention is by no means limited to the forms of embodiment described
heretofore and represented in the figures, on the contrary may such compressors be
realized in various variants without leaving the scope of the invention.
1. Compressor with at least one compressor stage and a moisture separator, whereby the
compressor stage comprises a housing (1) which is provided with an inlet (16-17-18)
for gas to be compressed, and an outlet (21) and at least two cooperating compressor
elements (2 and 3) mounted in this housing (1), at least one of which is rotatable,
characterized in that the inlet (16-17-18) is almost closed off from the compressor
stage by a rapidly rotating body (19) made of material having a sufficiently low flow
resistance for the gas to be compressed in order to let this gas pass, but which keeps
back moisture particles and other particles and whirls them radially away, which body
(19) is integrated in the housing (1).
2. Compressor according to claim 1, characterized in that the inlet (16-17-18) extends
over a shaft (13) with which the rotatable compressor element (3) is beared in the
housing (1) and the body (19) is fixed on this shaft (13).
3. Compressor according to claim 1 or 2, characterized in that the body (19) is situated
in a chamber (16) wich is formed by an enlargement of the inlet (16-17-18).
4. Compressor according to claim 3, characterized in that a discharge channel (20) is
connected to the chamber (16).
5. Compressor according to any of the claims 1 to 4, characterized in that the body (19)
has the shape of a disc.
6. Compressor according to any of the claims 1 to 5, characterized in that the body (19)
is manufactured of metal, synthetic material or ceramic material.
7. Compressor according to any of the preceding claims, characterized in that the body
(19) is manufactured of cellular material with open cells.
8. Compressor according to claim 7, characterized in that the body (19) is manufactured
by first covering plastic foam with open cells in a galvanic manner with metal or
covering it with ceramic material and subsequently removing the plastic foam thermically.
9. Compressor according to any of the claims 1 to 6, characterized in that the body (19)
is a brush.
10. Compressor according to claim 9, characterized in that the body (19) is a brush with
almost radially directed bristles (26).
11. Compressor according to any of the claims 1 to 10, characterized in that it is a screw
compressor and the compressor stage comprises two rotatable, screw-shaped compressor
elements (2 and 3) which, at both extremities, have a shaft (6-7-12-13) with which
they are beared in the housing (1) and the body (19) is mounted on one of these shafts
(6 or 13) in the inlet (16-17-18).
12. Compressor according to any of the preceding claims, characterized in that means are
provided in order to let the stream of the gas to be compressed through the body (19)
flow, at least partially, into the transverse direction, towards the geometrical rotation
axis of this body (19).
13. Compressor according to claim 11, characterized in that the aforementioned means comprise
at least one plate (24) which at least partially covers the side of the body (19)
directed towards the incoming gas to be compressed.
14. Compressor according to claim 13, characterized in that the aforementioned means comprise
a plate (24) which at least partially covers the side of the body (19) directed towards
the incoming gas to be compressed, and a plate (25) partially covering the opposite
side of the body (19).