Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to an oil separator,
vibration dampener and muffler for use on the outlet of a
compressor in a refrigeration system.
In any compression refrigerator, domestic or
commercial, or in an icemaking system for, for example, ice
rinks the compressor is a simple piston and cylinder arrange-
ment in which the piston is driven in the cylinder by a
~;~ compressor motor, electrical or internal combustion. The
refigerant passes through the cylinder and is compressed
there by the piston. It is later liquefied in the conden-
j ser.
.
The noise produced by the compressor is substan-
-~ tial and must be muffled. The compressed refrigerant vapour
¦ leaving the compressor often includes oil introduced from
the compressor crankcase, and, as with any reciprocable
engine, vibration is induced by the compressor~
Prior art treatment has largely concentrated on
muffling the noise, typically by using a sound absorbing
chamber with little function-in removing oil or vibration.
However, the present invention provides an apparatus able to
reduce the noise in refrigerator compressor to a satis-
factory, acceptable level, to reduce the vibration, and to
extract and separate oil from the compressed refrigerant.
Accordingly, in its broadest aspect, the present
invention is an oil separator and muffler for use on the
outlet side of a compressor and comprising: a chamber having
an inlet to receive compressed refrigerant from the com-
pressor; a perforate filter member in said chamber through
which the refrigerant can pass, said member being able to
receive non-gaseous impurities in said refrigerant; the
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perforate member defining a plurality of downwardly inclined
pathways in the chamber whereby liquid impurities can run
downwardly to the bottom of the chamber; outlet means in the
chamber for refrigerant that has passed through the per-
forate member; and a drain in the base of the chamber forimpurities gathered in the base of the chamber to be removed.
The perforate mem~er is desirably a rolled sheet
of a mesh comprising a plurality of strands, each strand
shaped and arranged to engage, at alternating joints, with
both neighbouring strands and in which each series of
alternating joints is generally in alignment. By this means
the liquid and solid content of the refrigerant, for example
oil and solid particles entrained by the oil or the re-
frigerant, are first removed by the mesh and then may run
down the mesh towards the drain in the base of the chamber
down the large number of roughly spiral pathways defined by
each strand.
Desirably the column is a pipe extendin~ into the
chamber from the chamber inlet to adjacent the chamber
outlet. There are openings in the pipe, adjacent the inlet,
to allow the refrigerant to pass through the pipe into the
chamber.
The drain is desirably provided with a valve,
typically a ba]l float valve, so that the oil gathered in
the base of the chamber may be withdrawn periodically. A
passageway for manual withdrawal of oil and for purging may
also be provided.
Aspects of the invention are illustrated, merely
by way of example, in the accompanying drawings, in which:
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Figure 1 is a sectional view through a muffler
according to the present invention;
Figure 2 is a section on the line 2-2 in Figure l;
~ Figure 3 is a section on the line 3-3 in Figure l;
!~ 5 Figure 4 is a section on the line 4-4 in Figure l;
Figure 5 is a section on the line 5-5 in Figure l;
and
Figure 6 is a plan view of a perforate filter
member.
The drawings illustrate an apparatus 2 to act as
an oil separate muffler on the outlet side of a refrigerant
compressor (not shown). The apparatus comprises a vessel 4
having a flrst opening 6 and a second opening 8 in opposed
ends 10 and 12 respectively. The first opening 6 acts as in
inlet, the second opening 8 acts as an outlet.
There is a pipe 14 extending into the vessel 4
through the inlet 6 to stop short of the outlet 8. Per-
forate baffles 16 and 18 divide the vessel 4 into an inlet
compartment 20, adjacent the first opening 6, an outlet
compartment 22, adjacent the second opening 8 and an inter-
mediate compartment 24, between the inlet and outlet com-
partments 20 and 22. The baffles have openings 26 in them.
There are outlets 28 in the pipe 14. The outlets
are in the inlet compartment 20 and have the form of elon-
gated slits arranged around the pipe 14 - see Figures 1 and
5. There is a first drain 30 in the inlet compartment 20.
The drain 30 has a valve 32. There is a second drain 42
with a valve 44.
A perforate filter material 34 in the form of a
metallic mesh, described later, is arranged in the inter-
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mediate compartment 24 and is positioned to form a pluralityof downwardly extending pathways. A plate 35 acts as a
baffle to close off the top of the pipe.
' Figure 6 shows a preferred configuration for mesh
34. The mesh comprises a plurality of strands 36 each
c~ formed into a series of loops. Each strand 36 then engages
both neighbouring strands 36 at a series of alternate joints
' 38 and 40. Joints 38 are generally aligned with each other.
~ Joints 40 are generally aligned with each other.
'" 10 The strands form a series of spiral pathways. To
introduce the mesh 34 into compartment 24 the mesh is rolled
into a cylinder then positioned in compartment 24 around
; pipe 14.
In use the illustrated device 2 is bolted directly
onto the outlet side of a refrigerator compressor. The
compressor refrigerant moves up the pipe 14. Some of the
refrigerant flows to the top of the pipe 14 where it is
stoped by the baffle 35 and forced downwardly to pass through
the outlets 28 in the inlet compartment 20. This change in
direction of flow of the refrigerant and the pressure drop
as it passes from the pipe 14, through the outlets 28,
precipitates much of the oil suspended, The refrigerant
then rises upwardly through the first perforate baffle 16l
through the mesh 34, through the second perforate baffle 18
to the outlet compartment 22 and then through the outlet 8.
In passing through the mesh 34 in particular the majority of
the remaining oil in the refrigerant is filtexed from it and
flows downwardly along the spiral pathways defined by the
strands of the perforate filter material. The oil passes
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through the holes 26 in the first baffle 16 into the inlet
: compartment 20. In the inlet compartment 20 the oil is
drawn off through drain 42 and may be returned to the
crankcase. First drain 30 may be used to draw off oil from
compartment 20 manually or may be used to purge the appara-
tus.
In use, the present invention has been found to
have about 35 to 40% better dampening or muffling of the
exhaust noise than a conventional muffler. Furthermore, it
has been found that vibration on a compressor has been
reduced to such a level that it is possible to balance a
coin on its edge on top of a compressor when the compressor
is fully loaded and at its maximum speed.
The apparatus is made of metal. Baffles 16 and
18 may he of expanded metal.
The present invention thus provides a simple yet
extremely efficient muffler that also acts as an oil separa-
tor and vibration damper.
