Abstract:
A deflector for an accumulator for an air conditioning system acts as a barrier to substantially prevent incoming liquid from entering a conduit which is primarily for gas. Fluid entering the accumulator comprises gas and liquid. The deflector also assists with the separation of gas from liquid, with reduced turbulence, to decrease the likelihood of liquid becoming re-entrained within the gas. An initial contact surface of the deflector receives the incoming fluid. The initial contact surface is substantially convex, so that liquid reflecting off the surface will be travel in a direction away (or different) from the flow of incoming fluid. The initial contact surface is also angled to direct liquid reflecting off it (or flowing down it) downward and outward.

Description:
FIELD OF THE INVENTION 
   The invention relates to suction accumulators for refrigeration or air/conditioning system use and is particularly concerned with deflectors used with accumulators. 
   BACKGROUND OF THE INVENTION 
   Closed-loop refrigeration systems conventionally employ a compressor that is meant to draw in gaseous refrigerant at relatively low pressure and discharge hot refrigerant at relatively high pressure. The hot refrigerant condenses into liquid as it is cooled in a condenser. A small orifice or valve divides the system into high and low-pressure sides. The liquid on the high-pressure side passes through the orifice or valve and turns into a gas in the evaporator as it picks up heat. (Some systems operate in “transcritical” mode, in that the hot refrigerant is merely cooled in a high side heat exchanger, now termed a “gas cooler”, and turns to gas plus liquid as it passes through the expansion device.) At low heat loads, it is not desirable or possible to evaporate all the liquid in the evaporator. However, excess liquid refrigerant entering the compressor (known as “slugging”) causes system efficiency loss and can cause damage to the compressor. Hence it is standard practice to include a reservoir between the evaporator and the compressor to separate and store the excess liquid. It is also a reservoir for excess refrigerant, which is typically added to the system during manufacture to compensate for unavoidable leakage during the working life of the system. This reservoir is called a suction line accumulator, or simply an accumulator. 
   An accumulator is typically a metal can, welded together, and often has fittings attached for a switch, transducer and/or charge port. One or more inlet tubes and an outlet tube pierce the top, sides, or occasionally the bottom, or attach to fittings provided for that purpose. The refrigerant flowing into a typical accumulator will impinge upon a deflector or baffle intended to reduce the likelihood of liquid flowing out the exit, generally by removing kinetic energy from the liquid so it settles quietly into the reservoir area without churning or splashing. Some patents describe accumulators without deflectors (such as U.S. Pat. No. 5,179,844 and U.S. Pat. No. 5,471,854). However, the lack of a deflector reduces effective reservoir volume and reduces efficiency by allowing churning and splashing that returns unnecessary liquid to the compressor—that is, by allowing liquid carryover. Moreover, even when deflectors have been used in the past, the deflectors have contributed to turbulence, when the incoming fluid rebounds off the deflectors. 
   A consequence of using a suction line accumulator is that compressor oil can become trapped within it. Compressor oil is circulated with the refrigerant in most systems in current usage. Even if a separator is used, a small amount of oil escapes into the system. This oil will find its way into the accumulator, and while liquid refrigerant may be expected to evaporate and return to circulation as needed, the oil does not evaporate. Some means must be provided to return this oil to circulation. A known practice is to use a J-shaped outlet tube to carry the exiting gaseous refrigerant from the top of the accumulator down to the bottom and then back up to the outlet from the accumulator. A carefully sized orifice at the bottom of this “J-tube” (sometimes also referred to as a “U-tube”) entrains the oil from the bottom of the liquid area into the stream of exiting gas. A recent development in accumulator design is to incorporate a plastic liner in the accumulator to assist with the oil pick up function (as shown in U.S. Pat. Nos. 06,612,128 and 06,463,757). 
   While previous deflector and accumulator designs have considered configurations to help prevent liquid refrigerant from exiting the accumulator, the previous designs do not appear to have addressed deflector design to improve the separation of liquid from vapour (while maintaining little liquid carryover). 
   Deflectors within accumulators have typically been designed to act only as shields to protect an outlet tube (or a J-tube or a gas flow tube (all of which may be referred to as a conduit primarily for gas)) from stray liquid refrigerant. It would be desirable to have a deflector that improves the separation of liquid and gas, while also protecting the outlet (or gas flow tube) from liquid refrigerant. 
   SUMMARY OF THE INVENTION 
   Computational Fluid Dynamics (CFD) calculations were used to study the path of fluid entering an accumulator and its reaction with the deflector surfaces in greater detail than previously. This allowed for a more in-depth study of the critical features of the deflector surfaces, and led to embodiments of the present invention incorporating novel deflector designs with improved configuration of deflector surfaces to disperse a greater amount of kinetic energy, thereby yielding improved gas/liquid separation. 
   The geometry of an initial contact surface of a deflector according to one embodiment of the present invention provides for inbound refrigerant and oil to be separated into its liquid and gas components with minimal or less interaction with the initial contact surface. The liquid and gas are allowed only minimal interaction upon contact with the deflector to avoid or reduce the likelihood of liquid re-entrainment. 
   In an accumulator without a liner, the liquid refrigerant and oil are then directed towards or near an inner surface of the accumulator, where gravity pulls the liquid down. 
   In one type of liner-style accumulator, the liquid refrigerant is then directed to interior walls of a liner while the gas flows toward a gas flow conduit. The oil and liquid refrigerant flow downward due to gravity, along an inside surface of the liner, to the bottom of the liner, while the gaseous refrigerant migrates toward an inlet of the gas flow conduit. The gas flow conduit is designed to direct the gas downward, underneath the liner. As gas flows under the liner, oil is entrained within the gas flow, through an oil bleed orifice located at or near a zenith in the liner. 
   In accordance with another aspect of the present invention, a deflector is provided for an accumulator where deflector surfaces disperse a greater amount of kinetic energy (than previous designs), thereby yielding improved gas/liquid separation. 
   Embodiments of the accumulators and related designs described herein could be used in air conditioning systems within vehicles. Embodiments of the accumulators and related designs described herein could also be used in stationary air conditioning and/or refrigeration systems (commercial and industrial). 
   According to a further aspect, the invention provides an accumulator for an air conditioning system, the accumulator comprising an outer body, a liner inside and spaced from the outer body, a conduit primarily for gas, and a deflector comprising a generally cylindrical circumference with an inner surface, wherein the inner surface of the circumference of the deflector is adjacent an inside surface of the liner and the deflector further comprising a separation/protection means to separate liquid from gas, wherein a portion of the separation/protection means comprises a barrier to substantially prevent liquid from entering the conduit and a portion of the separation/protection means comprises an initial contact surface for directing fluid away from a flow of incoming fluid, wherein the initial contact surface is substantially convex across the initial contact surface and the initial contact surface, as seen from an upper edge to a lower edge thereof, is angled away from the flow of incoming fluid. 
   According to a further aspect, the invention provides an accumulator for an air conditioning system, the accumulator comprising an inlet to supply incoming fluid, the inlet being located on a side of the accumulator, the accumulator further comprising a deflector and a conduit primarily for gas, the deflector comprising a separation/protection means to separate liquid from gas, wherein the separation/protection means comprises a barrier to substantially prevent liquid from entering the conduit and the separation/protection means comprises an initial contact surface for directing fluid down and away from a flow of incoming fluid, wherein the initial contact surface is substantially convex across the initial contact surface and the initial contact surface, as seen from an upper edge to a lower edge thereof, is angled away from the flow of incoming fluid. 
   According to yet another aspect, the invention provides an accumulator for an air conditioning system, the accumulator comprising: a deflector, a conduit primarily for gas, an outer body, an inlet to supply incoming fluid, the inlet being located within a top of the outer body to direct incoming fluid downward, and a separation/protection means to separate liquid from gas, the separation/protection means comprises a barrier to substantially prevent liquid from entering the conduit and a portion of the separation/protection means comprises an initial contact surface for directing fluid down and away from a flow of incoming fluid, wherein the initial contact surface is located generally opposite the inlet and the initial contact surface is substantially convex across the initial contact surface and slopes downward and outward to direct fluid in a direction away from an entrance of the conduit, and the initial contact surface as seen from an upper edge to a lower edge thereof, is angled away from the flow of incoming fluid, and the barrier of the separation/protection means comprises a wall extending across the deflector, with the inlet being located on one side of the barrier and an opening of the conduit being located on the other side of the barrier. 
   Different embodiments of the present invention may provide some of the following features and advantages: an accumulator having a deflector where the deflector not only helps prevent liquid from flowing directly into a conduit for gas, but also helps separation of liquid from gas; a deflector for an accumulator, where the configuration of the deflector disperses kinetic energy to provide improved liquid/gas separation; a deflector for an accumulator designed to separate liquid from gas with less interaction between the liquid and gas or with less turbulence to avoid or reduce the likelihood of liquid re-entrainment with the gas; an accumulator having a gas flow tube inside the accumulator where an entrance to the gas flow tube is located near a top of the accumulator, thereby increasing the effective accumulator volume (because a greater volume of liquid can be stored in the accumulator without the liquid flowing into the gas flow tube); an accumulator providing improved performance; an accumulator which is relatively easy to manufacture and fits multiple installation configurations; an accumulator which is more cost-effective and more flexible. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Preferred embodiments of the invention will now be described with reference to the attached drawings in which: 
       FIG. 1   a  is a perspective view of a side-in-side-out (SISO) accumulator (with some of the internal components shown in dotted outline) in accordance with an embodiment of the present invention; 
       FIG. 1   b  is a vertical sectional view of the accumulator of  FIG. 1   a , with arrows showing the direction of flow within the accumulator; 
       FIG. 1   c  is an exploded view of the accumulator of  FIG. 1   a;    
       FIGS. 2   a - 2   f  are different views of the SISO deflector of  FIG. 1   a  in which: 
       FIG. 2   a  is a perspective view looking down; 
       FIG. 2   b  is a perspective view looking up; 
       FIG. 2   c  is a top view; 
       FIG. 2   d  is a perspective sectional view; 
       FIG. 2   e  is a bottom view looking up; and 
       FIG. 2   f  is a side view of the initial contact surface; 
       FIG. 3  is a perspective sectional view of a top-in-side-out (TISO) accumulator in accordance with another embodiment of the present invention; 
       FIGS. 4   a - 4   d  are different views of a TISO deflector for the accumulator of  FIG. 3  in which: 
       FIG. 4   a  is a perspective view; 
       FIG. 4   b  is a perspective sectional view; 
       FIG. 4   c  is a top view; and 
       FIG. 4   d  is a bottom view; 
       FIG. 5   a  is a perspective view of a TISO J-tube style accumulator, with a portion of the accumulator top and bottom canisters removed for greater clarity, in accordance with another embodiment of the present invention; 
       FIG. 5   b  is a perspective view of the J-tube and deflector of  FIG. 5   a;    
       FIG. 5   c  is a perspective view of the J-tube and deflector of  FIG. 5   b , from a different perspective; 
       FIG. 6   a  is a perspective view of a SISO style accumulator, with a portion of the accumulator top and bottom canisters removed for greater clarity, in accordance with another embodiment of the present invention; 
       FIG. 6   b  is a perspective view of the J-tube and deflector of  FIG. 6   a.    
   

   DETAILED DESCRIPTION 
   As shown in  FIGS. 1   a - 1   c , an accumulator  20  has an outer body or housing formed by a top canister  22  and a bottom canister  24 . The top canister  22  fits securely and sealingly with the bottom canister  24 . The combination, in this embodiment, of the top canister  22  and the bottom canister  24  may be referred to as an outer body. The top canister  22  comprises and inlet fitting  26  and an outlet fitting  30 . In this embodiment, both the inlet fitting  26  and the outlet fitting  30  extend from or are formed in the side(s) or surface of the top canister  22 . The inlet fitting  26  is adapted to accommodate an inlet tube  28 . The outlet fitting  30  is adapted to accommodate an outlet conduit (not shown). The bottom canister  24  is generally cylindrical, with a closed bottom or floor  34  and an open top. 
   Within the accumulator  20  are (among other possible features): a liner  36 , which is secured within the bottom canister  24  of the accumulator  20 ; a deflector  40 , which is secured near a top portion of the accumulator  20 ; and a gas flow tube or conduit  42 , which extends within the accumulator  20 , partway along the height of the accumulator  20 . The accumulator may also incorporate a desiccant container  44 . 
   As shown in  FIG. 1   c , the liner  36  is generally cylindrical (which could also be considered to include a truncated cone shape, or an octagonal shape, or an oval shape or even a rectangular shape, for example), having an outer surface  46 , with a diameter slightly less than that of the bottom canister  24 .The top of the liner  36  is open. From the top of the liner  36 , the outer surface  46  of the liner  36  extends downward. Near a bottom portion of the liner  36 , the outer surface  46  extends inwardly to a nadir. From or near the nadir, the outer surface  46  extends inwardly and upwardly, to form a generally circular liner outlet or opening  50 . Formed within the liner  36 , advantageously at or near the nadir of the liner  36 , is an oil bleed orifice  52  (not shown). Extending along, and spaced evenly around the outer surface  46  of the liner  36 , are liner ribs  54 . 
   As suggested in  FIGS. 1   a - 1   c , the deflector  40  is secured within the accumulator  20 . The defector  40  is shown in different views in  FIGS. 2   a - 2   f . The deflector  40  has an outer wall (or circumference)  60 , having a generally truncated, conical shape, in this embodiment. The outer wall  60  could be considered generally cylindrical which could also describe many variations, including octagonal, oval, or rectangular shapes, for example. The deflector  40  has a lower portion  61 , which is indented by a step  62 . The outer wall  60  has an inner surface  63 . 
   The deflector  40  in this embodiment has an inlet entrance  64 , being generally unshaped and projecting out from the outer wall  60 . The inlet entrance  64  could assume other shapes, provided that fluid entering the accumulator  20  is directed into the deflector  40 . 
   Two vertical deflector ribs  66  are shown extending outward from the outer wall  60 . The vertical deflector ribs  66  are adapted to ensure that the deflector  40  fits securely within the top canister  22 . Other or additional means could also be used to secure the deflector  40  within the top canister  22 . 
   An initial contact surface  70  (which may also be referred to as a separation/protection means) extends across a portion of the deflector  40 , from one portion of the inner surface  63  of the outer wall  60  to another portion of the inner surface  63 . The initial contact surface  70 , in this embodiment, is generally centered (in the left-right orientation, as seen in  FIG. 2   c , for example) with respect to the inlet entrance  64 . A top (or upper) edge  73  of the initial contact surface  70  is approximately flush or even with a top edge of the deflector  40 . A lower edge  72  of the initial contact surface  70  creates a generally inverted U-shape. Although not shown, the lower edge  72  may have a beaded rim (or may be somewhat bulbous) to help liquid adhere to the edge  72 . The beaded rim helps to ensure that any liquid that adheres to the edge  72  is held on the rim and is directed towards the inner surface  63  and is not carried with the flowing gas. The lower edge  72  of the initial contact surface  70  may extend down at least as far, and, advantageously further, than a lower edge of the inlet entrance  64  of the deflector  40 . In a top view (looking down), the initial contact surface  70  has a slight arc, as shown, for example, in  FIG. 2   c . In other words, from the perspective of incoming fluid, the initial contact surface  40  is convex (in the direction across the initial contact surface  40 ). As well, from a top edge  73  to the lower edge  72  of the initial contact surface  70 , the initial contact surface  70  is angled inward. In other words, the initial contact surface  70 , as seen from the upper edge  73  to the lower edge  72 , is angled away from the flow of incoming fluid. 
   A gas flow tube socket  74  is supported within the deflector  40 . In this embodiment, the gas flow tube socket  74  is part of deflector  40 , although it need not be. The gas flow tube socket  74  has an opening  76 , adapted to fit securely around a top portion of the gas flow tube  42 . A generally cylindrical wall  80  defines the socket opening  76 . A step  81  (as shown in  FIG. 2   d ) may be formed within the wall  80  to form a stop or upper limit, against which an upper edge of the gas flow tube  42  may rest. The generally cylindrical wall  80  may extend upwardly into a flared upper surface  82 . In this embodiment, the socket  74  is secured within the deflector  40  by means of a support rib  84  (see  FIGS. 2   a ,  2   c  and  2   e ), extending from the socket  74  to the inner surface  63  of the outer wall  60 , and by an extension  86  (see  FIGS. 2   c  and  2   e ) of the flared upper surface  82  which extends between the flared upper surface  82  and a windward side of the initial contact surface  70 . 
   The opening  76  of the socket  74  is located below the top edge  73  of the initial contact surface  70 . 
   Advantageously, the deflector  40  (and/or the top canister  22 ) may have a means known to those skilled in the art (not shown) to help ensure that the inlet tube  28  and/or the inlet fitting  26  is/are tightly sealed so that all fluid from the inlet tube  28  is directed into the deflector  40 . 
   The deflector may be made from a suitable plastic, metal, or other material. Advantageously, the material chosen for the deflector will have similar expansion properties as the material(s) used to manufacture the accumulator, so that both the accumulator and the deflector will expand or contract in a comparable manner in response to the application of heat or cold. 
   The accumulator  20  may be assembled as generally suggested by  FIG. 1   c . The accumulator  20  may be assembled as follows. The desiccant container  44  is lowered into the liner  36 . The outer surface of the desiccant container  44  and the inner surface of the liner  36  are adapted to ensure that no fluid can flow between them. For example, the inner surface of the liner  36  may incorporate a small horizontal half bead (not shown), to provide a tight seal between the two surfaces. Many other techniques could be used to achieve the same result. 
   The gas flow tube  42  is then inserted through the opening formed within the desiccant container  44 . The outer diameter of the gas flow tube  42  is sized such that it is slightly smaller than the inner diameter of the opening formed within the desiccant container  44 , but still forms a tight seal between the two surfaces. 
   The deflector  40  then slides into position within the liner  36 . The lower portion  61  of the deflector  40  is sized to fit securely within a top portion of the liner  36 . A top edge of the liner  36  rests against the step  62  of the deflector  40 . The gas flow tube  42  fits securely within the opening  76  of the gas flow tube socket  74 . The flared upper surface  82  of the socket  74  reduces the pressure drop across the opening to the outlet tube  42 . 
   The liner  36  is then placed within the bottom canister  24 . There is a gap between an inside surface of the bottom canister  24  and the outer surface  46  of the liner  36  defined or determined (in this embodiment) by the extent to which the liner ribs  54  project from the outer surface  46 . The size of the gap may be adjusted. The larger the gap, the smaller the pressure drop through the accumulator  20 , at the expense of the volume within the liner  36 . 
   The top canister  22  is secured to the bottom canister  24 . Advantageously, there is a fitting or other adaptation (not shown) to help ensure a fluid-tight seal between a top edge of the deflector  40  and an inside surface of the top canister  22 . This helps prevent liquid carryover and may allow a top of the gas flow tube  42  to be near a top of the top canister  22 , thereby increasing the effective accumulator volume, because a greater volume of liquid can be held in the accumulator without the liquid entering the gas flow tube  42 . The top canister  22  is positioned on the deflector  40  such that the inlet entrance  64  of the deflector  40  meets up with and seals around inlet fitting  26  of the top canister  22 . 
   The top canister  22  and the bottom canister  24  may be made of aluminum or steel, for example, and welded together to form a hermetic seal. 
   In operation, fluid enters the accumulator  20  through inlet tube  28 . The arrows shown in  FIG. 1   b  illustrate the movement of the different components of the fluid. The fluid comprises liquid refrigerant, gaseous refrigerant and oil. The fluid entering the accumulator  20  flows against the initial contact surface  70 . Because the initial contact surface  70  is convex, liquid (refrigerant and oil) hitting the initial contact surface  70  and reflecting off it will be directed away from (that is, not directly towards) the stream of incoming fluid. Accordingly, the shape of the initial contact surface  70  helps to reduce re-entrainment of liquid into gas. As well, because the initial contact surface  70  is slanted or sloped inwardly from the top edge  73  to the lower edge  72 , liquid hitting the initial contact surface  70  and reflecting off it will be directed down. For liquid that flows along the initial contact surface  70 ,gravity causes the liquid to flow down the initial contact surface  70  and then along the inverted U-shaped lower edge  72  until the liquid contacts the inner surface  63  of the outer wall  60  of the deflector  40 . 
   The design of the deflector  40 , as described above, dissipates kinetic energy and improves the degree to which gaseous refrigerant is initially separated from liquid refrigerant and oil. Moreover, the shape or geometry of the initial contact surface  70  provides improved liquid/gas separation with less turbulence and reduced re-entrainment of gas with liquid. In other words, the liquid fluid is separated from the gaseous fluid with relatively minimal interaction with the gaseous refrigerant to avoid liquid re-entrainment. 
   When fluid flows into the initial contact surface  70 , the liquid refrigerant and oil are directed down to the interior walls of the liner  36 , while the gaseous refrigerant is separated and directed towards the gas flow tube  42 . The oil and liquid refrigerant then flow downward due to gravity, typically along the inside surface of the liner  36 . The liquid refrigerant and oil pass through the desiccant container  44 , which removes moisture from the liquid refrigerant, and the liquid then settles on the floor of the liner  36 . 
   Meanwhile, gaseous refrigerant flows into the opening  76  of the socket  74  and then down and out the gas flow tube  42  below the liner  36 . The gaseous refrigerant then flows up through the gap between the liner  36  and the bottom canister  24  and then up to the outlet fitting  30 , whereupon, the gaseous refrigerant exits the accumulator though the outlet conduit (not shown). As the gaseous refrigerant flows past the oil bleed orifice (not shown) near the nadir of the liner  36 , oil (and possibly some liquid refrigerant) passing through the oil bleed orifice is entrained within the flow of gaseous refrigerant, and is carried up and out the outlet conduit (not shown) with the gaseous refrigerant. 
   The embodiments described above relate to a side-in-side-out (SISO) accumulator. However, the principles described above could also be applied to accumulators having other configurations. For example, a vertical, sectional view of a particular top-in-side-out (TISO) liner style accumulator is shown in  FIG. 3 . Instead of the inlet tube  28  entering the accumulator  20  from the side, as in  FIG. 1   a ,  FIG. 3  shows a TISO accumulator  90 , having an inlet tube  92  which enters the accumulator  90  from the top. The major differences between the SISO accumulator  20  of  FIGS. 1   a  and  1   b  and the TISO accumulator of  FIG. 3  are the location of the inlet tubes  28  and  92  and the configuration of the deflectors  40  and  94 , respectively. 
   Different views of the TISO deflector  94  are shown in  FIGS. 4   a - 4   d . The deflector  94  has an outer wall (or circumference)  96 , which is generally cylindrical, with a slightly inwardly converging upper portion  100 , and a lower portion  102 , extending downward from a step  104 . Vertical external ribs  106  extend outwardly from the outer wall  96 . The outer wall  96  has an inner surface  110 . 
   A separation wall  112  extends across the deflector  94 , from one portion on the inner surface  110  to another portion on the inner surface  110 . The separation wall  112  has a wavy shape, as shown in the top view of  FIG. 4   c . The wavy shape, in this embodiment, is designed to cooperate with the particular shape and placement of an inlet. Different embodiments may incorporate different shapes for the separation wall. A top edge of the separation wall  112  is generally flush with a top edge of the outer wall  96 . 
   An initial contact surface  114  extends between the separation wall  112  and the inner surface  110  of the outer wall  96 . The initial contact surface  114 , as described below, is shaped so that liquid on the initial contact surface  114  flows towards, and then down, the inner surface  110  of the outer wall  96 . 
   The combination, in this embodiment, of the separation wall  112  and the initial contact surface  114  may be referred to as a separation/protection means. 
   The initial contact surface  114  has an apex line (or ridge)  116 . In this embodiment, the initial contact surface  114  is generally symmetrical about the apex line  116 . Flow directing surfaces  118  and  120  are sloped both downward and towards the inner surface  110  of the outer wall  96 . An outer flow directing surface  122  is positioned between the separation wall  112  and the flow direction surface  120 , on each side of the apex line  116 . Each outer flow directing surface  122  is sloped downward and towards its corresponding flow directing surface  120 . 
   The overall shape of the initial contact surface  114  is substantially convex (in the direction across the initial contact surface  114 ), even though portions of the initial contact surface  114  may not be convex. 
   As shown in the top view of  FIG. 4   c , fluid openings  124  are formed between the initial contact surface  114  and the inner surface  110  of the outer wall  96 . Edges of the initial contact surface  114  adjacent the fluid openings  124  may have beaded rims (or may be somewhat bulbous) to help liquid adhere to the rims, where the liquid is then directed toward the inner surface  110 (and away from the gas flow). As shown in the top and bottom views of  FIGS. 4   c  and  4   d , a socket  126  (of configuration similar to the socket  74  described above with respect to the SISO accumulator  20 ) is supported by the separation wall  112  and the underside of the initial contact surface  114 . The socket  126  has a socket opening  130 . 
   In operation, the deflector  94  and a top canister  132  of the accumulator  90  fit together so that the top edge of the separation wall  112  and the top edge of the outer wall  96  form a fluid tight seal against the top canister  132  (or against a fitting (not shown) within the top canister  132 ). Fluid from the inlet tube  92  is directed down into the accumulator  90 , between the separation wall  112  and the inner surface  110  of the outer wall  96 . 
   Fluid is directed towards the initial contact surface  114 , where gaseous refrigerant is mostly (or at least partly) separated from liquid refrigerant and oil. The gaseous refrigerant flows though the fluid openings  124  formed in the deflector  94  and then into the socket opening  130  and down the gas flow tube  42  and then proceeds as described above with respect to the SISO accumulator  20 . The liquid refrigerant and oil, upon hitting the initial contact surface  114 , flow down the initial contact surface  114  to the inner surface  110  of the outer wall  96 . The liquid refrigerant and oil then flow down the inner surface  110  and then down the inner surface of the liner  36  and then proceed as described above with respect to the SISO accumulator  20 . 
   The embodiments of deflectors described above relate to a particular type of liner-style accumulators. However, the principles described above could be applied to a liner style accumulator of any type. In those cases, the configuration of the deflector may be modified to accommodate the particular features of the different types of liner-style accumulators. 
   Moreover, the deflector design principles described above could also be applied to accumulators that do not incorporate liners. In other words, the principles described above could be applied to other situations where it would, for example, be desirable to separate gaseous fluid from liquid fluid with minimal (or less) re-entrainment of liquid fluid with gaseous fluid and/or with less churning of the separated liquid fluid. For a J-tube style accumulator, the deflector would be adapted to protect an inlet of a J-tube from liquid entering the accumulator. Because a J-tube style accumulator does not typically incorporate a liner, a deflector used in such a liner would likely be modified from the designs described above. For example, the outer wall  60  of the deflector  40  shown in  FIG. 2   a  could be modified for a J-tube style accumulator by flaring out the lower portion  61  so that the lower portion  61  engages (or comes close to engaging) an inner surface of the bottom canister  24  of the accumulator, so that liquid flowing down the inner surface  63  of the deflector  40  will be directed to the inner surface of the bottom canister  24  and be more likely to flow down the inner surface of the bottom canister  24 . 
   Alternatively, in an accumulator without a liner, it would not be necessary for a deflector to have a surrounding outer wall, such as outer wall  60  as shown in  FIG. 2   a . In other words, in an accumulator without a liner, because it would be desirable to direct liquid to flow down an inner surface of the bottom canister  24  (as opposed to an inner surface of a liner), an outer wall of the deflector, such as outer wall  60  of the deflector of  FIG. 2   a  could be omitted. 
   An embodiment of one such SISO J-tube style accumulator is shown in  FIGS. 6   a  and  6   b . In this embodiment, fluid enters an accumulator  160  and hits the deflector  162 . The accumulator  162  has an inner surface  164 . Although perhaps not clear from  FIG. 6   a , the bottom edge of the deflector  162  comes into contact with, or approaches the inner surface  164  of the accumulator  160 . 
   Similarly, a TISO accumulator without a liner could also use the concepts described above. For example, the deflector  94  shown in  FIG. 4   a  could be modified as required. The lower portion  102  in  FIG. 4   a  could be flared outward to approach or meet an inner surface of the bottom canister  24 . Alternatively, the outer wall  96  could be completely or partially omitted so that liquid, instead of being directed to the inner surface  110  of the deflector  94 , would be directed towards an inner surface of the bottom canister, as suggested in  FIGS. 5   a - 5   c . An example of one such deflector is described as follows. 
     FIG. 5   a  shows a J-tube style accumulator  138 , having a top canister  139  and a bottom canister  140 . The accumulator  138  incorporates a J-tube  144  (which could also be referred to as a U-tube). The accumulator  138  has an inner surface  142 . The accumulator  138  has a deflector  146 , having a separation wall  150  and an initial contact surface  152 . The deflector  146  in this embodiment is substantially similar to the combination of the separation wall  112  and the initial contact surface  114  of the TISO deflector  94  of  FIGS. 4   a - 4   c . One difference between the embodiment of  FIGS. 4   a - 4   c  from the embodiment of  FIGS. 5   a - 5   c , is that in the embodiment of  FIGS. 4   a - 4   c , fluid reflecting off the initial contact surface  114  is directed towards the inner surface  110  of the deflector  94 . In contrast, fluid reflecting off the initial contact surface  152  of the deflector  146  of the embodiment of  FIGS. 5   a - 5   c  is directed to the inner surface  142  of the accumulator  138 . 
   The deflector  146  shown in the embodiment of  FIGS. 5   a - 5   c  is secured to the J-tube  144 . In different embodiments (not shown) the deflector could be secured to the top canister  139  or possibly the bottom canister  140 . 
   Numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. For example, the embodiments of the accumulator designs described above have a single inlet. However, different embodiments could have more than a single inlet.