U.S. patent application number 11/912233 was filed with the patent office on 2009-02-12 for suction muffler for a refrigeration compressor.
This patent application is currently assigned to WHIRLPOOL S.A.. Invention is credited to Eduardo De Souza Alvarenga, Rodrigo Link.
Application Number | 20090038329 11/912233 |
Document ID | / |
Family ID | 36930331 |
Filed Date | 2009-02-12 |
United States Patent
Application |
20090038329 |
Kind Code |
A1 |
Alvarenga; Eduardo De Souza ;
et al. |
February 12, 2009 |
SUCTION MUFFLER FOR A REFRIGERATION COMPRESSOR
Abstract
A suction muffler for a refrigeration compressor, comprising a
hollow body defining at least one dampening chamber that carries a
gas inlet duct and a gas outlet duct presenting an inlet opening
and an outlet opening, for communicating the interior and the
exterior of the dampening chamber, at least one of the gas inlet
and gas outlet ducts presenting at least one closed end, one of the
inlet and outlet openings being positioned at a certain distance
from said closed end, smaller than the distance of said opening in
relation to the other opening of the same duct and in a region of
the latter presenting a minimum acoustic pressure for a determined
frequency, the dimensioning of said duct and of the cross section
of the first of said openings being achieved so as to minimize the
gas pulsation noises inside the suction muffler.
Inventors: |
Alvarenga; Eduardo De Souza;
(Joinville - Sc, BR) ; Link; Rodrigo;
(Joinville-Sc, BR) |
Correspondence
Address: |
DARBY & DARBY P.C.
P.O. BOX 770, Church Street Station
New York
NY
10008-0770
US
|
Assignee: |
WHIRLPOOL S.A.
Sao Paulo - SP
BR
|
Family ID: |
36930331 |
Appl. No.: |
11/912233 |
Filed: |
May 2, 2006 |
PCT Filed: |
May 2, 2006 |
PCT NO: |
PCT/BR2006/000085 |
371 Date: |
November 2, 2007 |
Current U.S.
Class: |
62/296 ;
417/312 |
Current CPC
Class: |
F04B 39/0066
20130101 |
Class at
Publication: |
62/296 ;
417/312 |
International
Class: |
F25D 19/00 20060101
F25D019/00; F04B 53/00 20060101 F04B053/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 3, 2005 |
BR |
PI0501740-8 |
Claims
1. A suction muffler for a refrigeration compressor mounted within
a shell, said suction muffler comprising a hollow body defining at
least one dampening chamber that carries a gas inlet duct having an
inlet opening external to the dampening chamber and an outlet
opening in the interior of the dampening chamber and a gas outlet
duct presenting an inlet opening in the interior of the dampening
chamber and an outlet opening external to said dampening chamber,
wherein at least one of the gas inlet duct and gas outlet duct
presents at least one closed end one of the inlet and outlet
openings being positioned at a certain distance from said closed
end, along the respective duct, smaller than the distance of said
opening in relation to the other opening of the same duct and in a
region of the latter presenting a minimum acoustic pressure for a
determined frequency, the dimensioning of said duct and of the
cross section of the first of said openings being achieved so as to
minimize the gas pulsation noises inside the suction muffler.
2. The suction muffler, as set forth in claim 1, wherein the gas
inlet duct has its inlet opening connected to a suction line of a
refrigeration system to which the compressor is coupled.
3. The suction muffler, as set forth in claim 1, wherein the gas
outlet duct has its outlet opening in fluid communication with a
suction orifice provided in a valve plate of the compressor.
4. The suction muffler, as set forth in claim 3, wherein the outlet
opening of the gas outlet duct is maintained in fluid communication
with the suction orifice through another dampening chamber having
another gas outlet duct presenting an inlet opening opened to the
interior of said other dampening chamber and an outlet opening
connected to the suction orifice.
5. The suction muffler, as set forth in claim 4, wherein at least
one of the gas inlet and gas outlet ducts in the other dampening
chamber has at least one closed end, one of the inlet and outlet
openings being positioned at a certain distance from said closed
end, along the respective duct, smaller than the distance of said
opening in relation to the other opening of the same duct and in a
region of the latter-presenting a minimum acoustic pressure for a
determined frequency, the dimensioning of said duct and of the
cross section of the first of said openings being achieved in such
a way as to minimize the gas pulsation noises in the interior of
the suction muffler.
6. The suction muffler, as set forth in claim 1, wherein the closed
end is submitted to the same gas pressure reigning in said region
of minimum acoustic pressure.
7. The suction muffler, as set forth in claim 6, wherein the
distance between the medium line of the first of said openings and
the closed end of the gas duct is greater than half the diameter of
said opening.
8. The suction muffler, as set forth in claim 7, wherein the closed
end is defined in a plane intercepted by the direction of the gas
flow passing through the first of said openings of the gas
duct.
9. The suction muffler, as set forth in claim 8, wherein the closed
end is defined in a plane parallel to the direction of the gas flow
passing through the first of said openings of the gas duct.
10. The suction muffler, as set forth in claim 1, wherein at least
one closed end is defined by a wall portion of the hollow body.
11. The suction muffler, as set forth in claim 1, wherein at least
one closed end carries a cover.
12. The suction muffler, as set forth in claim 11, wherein the
cover is incorporated to the respective closed end.
Description
FIELD OF THE INVENTION
[0001] The present invention refers to a suction muffler for a
refrigeration compressor, particularly of the type used in small
refrigeration systems, such as refrigerators, freezers, water
fountains, refrigerated counters, and which is provided in the
region where the refrigerant gas is admitted to the hermetic
compressor.
BACKGROUND OF THE INVENTION
[0002] As a rule, compressors of the refrigeration systems present,
at the suction side thereof, an acoustic dampening system or
suction muffler provided inside the shell and which conducts the
gas coming from the suction line of said refrigeration systems to a
suction valve that is conventionally disposed to provide the
selective and automatic opening of a respective suction orifice of
a valve plate in which the suction and discharge valves of the
compressor are usually mounted.
[0003] The suction muffler has, several important functions to the
adequate operation of the compressor, such as: to direct the gas,
to attenuate the noise resulting from pulsation provoked by
suction, to thermally insulate the gas being drawn into the
cylinder, and to control the dynamics of the suction valve.
[0004] The present refrigeration compressors use the suction
muffler of the volume-tube type. This type of suction muffler
usually consists of a sequence of volumes interconnected by tubes
which conduct the gas coming from the suction line directly to the
suction valve. At present, said tubes presenting open ends for the
passage of refrigerant gas.
[0005] Gas displacement produces pulses, generating noises that are
propagated in a direction that is opposite to the gas flow toward
the suction valve. The more efficient the suction muffler at its
acoustic outlet through which the gas is admitted into the muffler,
the lower said pulses.
[0006] The influence of the suction muffler on the performance of
the compressor is highly important and the dimensioning of both the
inner volumes and the length of the tubes of the suction muffler
determine, to a great extent, the efficiency of the compressor.
While widely used, the known suction mufflers of the volume-tube
type have the disadvantage of presenting noise peaks in the
specific operational modes of said tubes.
OBJECTS OF THE INVENTION
[0007] It is an object of the present invention to provide a
suction muffler for a reciprocating hermetic compressor, which does
not present the inconveniences of the known prior art solutions,
producing a better noise attenuation of the pulses resulting from
gas being drawn to the suction valve.
[0008] It is a more specific object of the present invention to
provide a suction muffler as cited above, which allows optimizing
the acoustic attenuation for specific frequency bands.
SUMMARY OF THE INVENTION
[0009] These and other objects of the present invention are
achieved by the provision of a suction muffler for a refrigeration
compressor mounted within a shell, said suction muffler comprising
a hollow body defining at least one dampening chamber that carries
a gas inlet duct having an inlet opening external to the dampening
chamber and an outlet opening in the interior of the dampening
chamber, and a gas outlet duct presenting an inlet opening in the
interior of the dampening chamber and an outlet opening external to
said dampening chamber, at least one of the gas inlet and gas
outlet ducts presenting at least one closed end, and one of the
inlet and outlet openings being positioned at a certain distance
from said closed end, along the respective duct, smaller than the
distance of said opening in relation to the other opening of the
same duct and in a region of the latter presenting a minimum
acoustic pressure for a determined frequency, the dimensioning of
said duct and of the cross section of the first of said openings
being achieved so as to minimize the gas pulsation noises inside
the suction muffler.
[0010] The dimensioning of said gas duct and of the cross section
of said opening is achieved so as to minimize the gas pulsation
noises inside the suction muffler which are generated upon the
closing and opening of the suction valve. The region of minimum
acoustic pressure is represented as a nodal point of the acoustic
mode of the duct.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention will be described below based on the appended
drawings, given by way of example of one embodiment of the
invention and in which:
[0012] FIG. 1 illustrates, schematically and partially, a
longitudinal sectional view of a compressor carrying a suction
muffler;
[0013] FIG. 2 illustrates, schematically, a partial cross-sectional
upper plan view of a suction muffler constructed according to the
present invention, presenting a dampening chamber carrying a gas
inlet duct and a gas outlet duct of the suction muffler;
[0014] FIG. 3 illustrates, schematically, a longitudinal sectional
view of a construction for a suction muffler of the present
invention, according to line III-III of FIG. 2, presenting a
dampening chamber carrying a gas inlet duct of the suction
muffler;
[0015] FIG. 4 illustrates, schematically, another longitudinal
sectional view of the suction muffler of the present invention,
according to line IV-IV of FIG. 2, showing the gas outlet duct of
the suction muffler;
[0016] FIG. 5 illustrates, schematically, a longitudinal sectional
view of another construction for a suction muffler of the present
invention, presenting two dampening chambers carrying respective
gas inlet and gas outlet ducts of the suction muffler; and
[0017] FIG. 6 illustrates, schematically, a graph showing the
attenuation curve obtained, for frequency 2 kHz, with a muffler
construction of the prior art (full lines) and with the
construction of the present invention (broken lines).
DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
[0018] The present invention will be described for a compressor of
the type used in refrigeration systems and comprising, inside a
hermetic shell 1, a motor-compressor assembly having a cylinder
block in which is defined a cylinder 2 lodging, at one end, a
piston 3, and having an opposite end closed by a cylinder cover 4
defining, therewithin, a suction chamber (not illustrated) and a
discharge chamber 5 in selective fluid communication with a
compression chamber 6 defined inside the cylinder 2 between a top
portion of the piston 3 and a valve plate 7 provided between the
opposite end of the cylinder 2 and the cylinder cover 4, through a
suction orifice 7a and a discharge orifice 7b, which are
respectively closed by suction and discharge valves 8a, 8b.
[0019] According to the illustrations, the gas drawn by the
compressor and coming from a suction line (not illustrated) of the
refrigeration system to which the compressor is coupled, reaches
the interior of the shell 1 through the suction muffler, generally
provided inside said shell 1 and maintained in fluid communication
with the interior of the suction chamber of the compressor.
[0020] As illustrated in the enclosed drawings, the suction muffler
of the present invention comprises a hollow body 10, which is
generally made of a material of low thermal conductivity, such as
plastic, defining at least one dampening chamber 13, for example
internal to said hollow body 10 and carrying a gas inlet duct 20
having an inlet opening 21 external to the dampening chamber 13 and
an outlet opening 22 in the interior of the dampening chamber 13
and a gas outlet duct 30 presenting an inlet opening 31 in the
interior of the dampening chamber 13 and an outlet opening 32
external to said dampening chamber 13.
[0021] According to the present invention, at least one of the gas
inlet and gas outlet ducts 20, 30 presents at least one closed end
23, 33, one of the inlet and outlet openings 21, 22, 31, 32 being
positioned at a certain distance from the closed end 23, 33, along
the respective duct 20, 30, smaller than the distance of said
opening in relation to the other opening of the same duct 20, 30
and in a region thereof presenting a minimum acoustic pressure for
a determined frequency, the dimensioning of said duct 20, 30 and of
the cross section of the first of said openings 21, 31; 22, 32,
being achieved in such a way as to minimize the gas pulsation
noises inside the suction muffler.
[0022] According to the present invention, each closed end 23, 33,
is submitted to the same gas pressure reigning in said region of
minimum acoustic pressure.
[0023] In the construction illustrated in FIGS. 2 and 3, the
suction muffler presents a dampening chamber 13 provided with a gas
inlet duct 20 having its inlet opening 21 in fluid communication
with the gas supply to the compressor, connected to the suction
line of the refrigeration system to which the compressor is coupled
and its outlet opening 22 in fluid communication with a suction
side of the compressor, for example, directly connected to the
suction orifice 7a of the valve plate 7 of the compressor.
[0024] According to a constructive option of the present invention,
the outlet opening 32 of the gas outlet duct 30 of a first
dampening chamber 13 is maintained in fluid communication with the
suction orifice 7a through another dampening chamber 14, as for
example illustrated in FIG. 5, said other dampening chamber 14
having another gas outlet duct 40 having an inlet opening 41 opened
to the interior of said other dampening chamber 14 and an outlet
opening 42 connected to the suction orifice 7a.
[0025] In the construction illustrated in FIG. 5, the suction
muffler comprises a hollow body 10 defining two dampening chamber
13, 14, for example, internal to said hollow body 10 and separated
from each other by a common wall 15. To the interior of a first of
said dampening chambers 13 projects the outlet opening 22 of the
gas inlet duct 20, and an inlet opening 31 of a gas outlet duct 30
has its outlet opening 32 projecting to the interior of the other
dampening chamber 14, providing fluid communication between said
dampening chambers 13, 14.
[0026] In this construction, to the interior of the other dampening
chamber 14 also projects the inlet opening 41 of another gas outlet
duct 40 having an outlet opening 42 to be connected to the suction
orifice 7a in the valve plate 7.
[0027] According to the present invention, each of the gas ducts
20, 30, 40 presents a geometry defined so that at least one of its
inlet and outlet openings 21, 22, 31, 32, 41, 42 is positioned at a
certain distance from each closed end 23, 33 of the same duct 20,
30, 40, along this duct 20, 30, 40, smaller than the distance of
said opening in relation to the other opening of the same duct 20,
30, 40 and in a region thereof presenting a minimum acoustic
pressure for a determined frequency, the dimensioning of said duct
20, 30, 40 and of said cross section of the first of said openings
21, 31; 22, 32; 41, 42, being defined so as to minimize the gas
pulsation noises in the interior of the suction muffler, the
distance between the medium line of the first of said openings 21,
31; 22, 32; 41, 42 and the closed end 23, 33 of the same duct 20,
30, 40, in which is provided said closed end 23, 33, being greater
than half the diameter of said opening 21, 31; 22, 32; 41, 42.
[0028] In a constructive option illustrated in FIGS. 2, 3 and 4,
the hollow body 10 of the suction muffler presents, internally,
only one dampening chamber 13, to the interior of the latter
projecting the outlet opening 22 of the gas inlet duct 20 and the
inlet opening 31 of the gas outlet duct 30. However, in this
construction, the gas inlet duct 20 has a closed end 23 located
closer to the inlet opening 21 of said gas inlet duct 20 and
defined in a nodal region of minimum acoustic pressure. In this
construction, the gas outlet duct 30 may or may not have a closed
end. FIG. 4 illustrates a construction in which the gas outlet duct
30, illustrated in FIG. 2, has a closed end 33 provided closer to
the inlet opening 31 of said gas outlet duct 30.
[0029] According to the present invention, each gas inlet and gas
outlet duct 20, 30, 40 may present at least one respective closed
end 23, 33 in each dampening chamber 13, 14.
[0030] In the construction illustrated in FIG. 5, the gas inlet
duct 30 presents a closed end 33 in the interior of the dampening
chamber 13, closer to the inlet opening 31 of said gas inlet duct
30. Though not illustrated, it should be understood that the closed
end may be also provided adjacent to the outlet opening of the same
gas duct.
[0031] In another constructive alternative, not illustrated, the
opening defined in the region of minimum acoustic pressure is one
of the inlet and outlet openings 21, 22, 31, 32, 41, 42 of each gas
inlet and gas outlet duct 20, 30, 40 inside the hollow body 10, in
a respective dampening chamber 13, 14.
[0032] From the definition of the geometry of the gas duct 20, 30,
40 (or other ducts that might be provided in the hollow body 10)
provided with at least one closed end 23, 33, an acoustic mode is
determined to have a certain attenuated frequency, said attenuation
occurring in the region of the gas duct or ducts 20, 30, 40 having
a minimum acoustic node, that is, in the regions with minimum
pressure. The pressures reigning in each of the gas ducts 20, 30,
40 of the suction muffler are the stationary or acoustic pressures
presenting regions of minimum and maximum pressure. Once the
minimum pressure regions are determined, one can determine the
region to provide said inlet opening 21, 31, 41 or outlet opening
22, 32, 42 and the respective closed ends 23, 33 of each duct 20,
30, 40. Each gas duct 20, 30, 40, provided with an opening or
openings in nodal regions, presents each respective closed end 23,
33 constructed in such a way as to avoid any direct communication
of the gas with the interior of the hollow body 10 of said suction
muffler.
[0033] In a constructive option of the present invention, as
illustrated in FIG. 3, an inner sidewall portion of the hollow body
10 defines a cover portion in which is tightly fitted the closed
end 23, 33 of a gas duct 20, 30, 40, said cover portion being
retained therein by appropriate retaining means, such as glue,
clamps, projections or by interference. In the constructive options
illustrated in FIGS. 4 e 5, each closed end 23, 33 incorporates the
respective cover, which is for example defined as a single piece
with the remaining of the respective body of the gas duct 20, 30,
40, for example by injection, jointly with the formation of the
duct in a single piece, or by over-injection.
[0034] In another constructive option of the present invention, the
gas duct 20, 30, 40 carries and secures a cover closing an adjacent
closed end 23, 33.
[0035] According to the present invention, the closed end 23, 33 is
defined in a plane intercepted by the direction of the gas flow
passing through the opening defined in a nodal region of minimum
acoustic pressure of the respective gas duct 20, 30, 40, said
opening positioning allowing the pressure to be taken at a point of
minimum acoustic pressure, generating high acoustic attenuation in
a determined frequency band, as illustrated in FIG. 6.
[0036] In another constructive option, the closed end 23, 33 is
defined in a plane parallel to the direction of the gas flow
passing through the first of said openings 21, 31; 22, 32, 42 of
one of the first, second and third gas ducts 20, 30, 40, said
opening positioning also allowing the pressure to be taken at a
point of minimum acoustic pressure, generating high acoustic
attenuation in a determined frequency band, as illustrated in FIG.
6.
[0037] Specific aspects of the invention are shown in the figures
of the drawings for convenience only, as each aspect can be
combined with other aspects according to the invention. Other
embodiments will be recognized as possible by those skilled in the
art and should be included in the scope of the claims. Accordingly,
the description above should be construed as illustrative and not
as limitative of the scope of protection of the invention. All such
obvious modifications and alterations are found in the scope of
protection defined in the appended claims.
* * * * *