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(11) | EP 1 342 965 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
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Integrated condenser-receiver desiccant bag and associated filter cap Beutel mit Trocknungsmittel und dazugehöriger Filterdeckel für Verflüssiger mit Einbausammler Sac de déshydratant et capuchon de filtre associé pour condenseur à réservoir intégré |
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| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
[0001] Desiccant containing packets have been employed in small diameter receivers that are juxtaposed along one of the condenser headers in an integrated type condenser-receiver. These integrated condenser-receiver structures eliminate the need for separate tubing to connect the condenser with the receiver and have become popular due to their reduced spatial requirements. For instance, in one integrated condenser-receiver disclosed in US-A-5,813,249, the overall dimensions of the integral unit are from about 300 mm - 400 mm in height and about 300 mm - 600 mm in width.
[0002] In the integrated type condenser-receiver design reported in the '249 patent, the axes of the receiver canister and associated header are parallel with the canister attached to and contiguous with the header. The desiccant containing package positioned in the receiver dries refrigerant liquid (and the oil and moisture entrained therein) prior to passage of the dried refrigerant to a supercooler unit that is formed integrally with the condenser.
[0003] Due to the small diameter of the receiver canister in such integrated structures, the desiccant containing package which is to be positioned therein must also comprise a small diameter substantially cylindrical pouch or packet. Typically, automotive manufacturers desire placing a fluorescent tracer dye wafer or the like in the desiccant package so that leaks in the refrigeration system can be readily determined by use of an ultraviolet light source. See for instance US-A-5,149,453.
[0004] At present, these tracer dye waters are available in disk shapes having a 9.5 mm (3/8") diameter and 9.5 mm (3/8") thickness. Typically, commercial felts that are used to form desiccant containing packages are on the order of about 1.5 mm - 3 mm (0.060"-0.120") in thickness. When such conventional materials are used to form a desiccant package for reception within these small diameter receivers, the internal diameter and the internal cross sectional area thereof are so small as to hinder insertion of a dye wafer therein
[0005] One bag used in the receiver of an integrated condenser-receiver is fabricated by folding, over the felt or other bag material and then sewing the one edge shut, thus forming a lopsided tube. One end of this tube is then sewn shut and the packet created by this is filled with desiccant and then the open end is sewn shut creating the bag. The sewn edge along the length of the bag protrudes out from the surface and creates a hindrance to installing the bag in a small diameter integrated receiver condenser. The construction of the bag is labour intensive and therefore expensive to fabricate.
[0006] US-A-3308957, which reflects the preamble of claim 1, discloses a desiccant containing package comprising an elongated casing having connections at opposite ends for connecting the package in a refrigerant line, and an elongated bag made from mesh material housed within the casing and extending from one end to the other of the casing. One end and an intermediate portion of the bag are flattened and sealed to form a closed portion of the bag which is filled with desiccant. The other end of the bag communicates with one of the end connections of the casing and the adjacent portion of the bag between said other end and the intermediate portion is expanded by a spring and serves to facilitate straining of the refrigerant.
[0007] WO-A-01/24911 describes a desiccant cartridge for positioning within the canister and about the fluid flew tube of a receiver/dryer and accumulator assembly. The cartridge comprises a cup having coaxial, spaced inner and outer cylindrical walls connected, at one end, by a transverse portion to define a chamber containing desiccant particles. The opposite end of the chamber is closed by a cap and both the transverse portion and the cap are perforated to permit fluid to be dried to flow through the cartridge.
[0008] The present invention resides in a desiccant containing package as set forth in claim 1 hereof. A very thin non-woven porous nylon material may beneficially be used to form the pouch so that the desiccant containing package will fit snugly within the small diameter receiver or other fluid flow tube or canister of an integrated type condenser-receiver. The thinness of the material, when formed into a cylindrical cross-sectioned pouch, will allow sufficient room within the package for insertion of a tracer dye wafer or the like therein. At the same time, the porosity of the fabric will permit adequate fluid permeability so that the refrigerant liquid can permeate the package and dry upon contact with the desiccant housed therein.
[0009] Specifically, it has been found that non-woven spun bonded nylon material is especially efficacious in forming these small diameter desiccant packages. This material is also sometimes referred to as being a point bonded nylon. Although others have proposed using this particular material to form a saddle-bag shaped absorbent unit of automotive accumulators (see US-A-6,038,881), one artisan has opined that such use is disfavored since allegedly the material is "difficult to form thermally into concave configurations, had high scrap rates and downtime, and lower thermal strength." (See US-A-6,038,881)
[0010] Accordingly, it was surprising to find that this particular non-woven material could be easily and durably formed by ultrasonic sealing methods into a small diameter, generally cylindrical shape so as to house desiccant and a tracer dye wafer therein. These generally cylindrical pouches are especially useful when positioned as a desiccant package in the receiver associated with the aforementioned integrated condenser-receiver.
[0011] Additionally, so as to enhance the filtering efficacy of the desiccant package, the solid particle filter surface and the rim area of the structure are provided as a component of the pouch to minimize bypassing of the desiccant containing package by refrigerant fluid and to enhance filtering efficacy.
[0012] The present invention thus serves to provide a desiccant containing or adsorbent package adapted for use in a fluid flow tube of an automotive refrigerant system. The fluid flow tube may be, for example, an accumulator or receiver/drier canister or the like. The fluid flow tube or canister has a substantially cylindrical side wall and opposing first and second end walls. An inlet opening is formed within the side wall proximate the first end wall, while an outlet opening is formed within the side wall proximate the second end wall.
[0013] The adsorbent package of the present invention includes a pouch preferably formed from a tubular strip of non-woven spun bonded nylon material. A first end of the pouch is sealed in a conventional manner to form an end seam. The interior, as defined by the pouch, is then filled with an appropriate granular adsorbent material.
[0014] In one embodiment, the second end of the pouch slidably and sealingly receives the filter cap. The filter cap includes a body having a cylindrical side wall and a porous end wall which is preferably formed integrally with the side wall. The end wall includes a plurality of apertures sized so as to permit refrigerant fluid flow but to restrict desiccant from passing therethrough. The cap includes the attachment device for securing the pouch of the desiccant bag to the cap body. The attachment device comprises an annular ring extending radially outwardly from the body of the cap and positioned along the skirt portion of the cap body. A resilient sealing rim is formed proximate the porous end wall and extends radially outwardly from the body. The sealing rim forms a living seal by slidably and sealingly engaging an inner surface of the cylindrical side wall of the canister.
[0015] In operation, refrigerant flows through the inlet opening of the canister and is directed through the porous end wall of the cap by the sealing rim. As may be appreciated, all fluid flow is directed through the cap by sealing engagement between the sealing rim and the cylindrical side wall of the canister. The refrigerant flows through the cap, passing through the desiccant and pouch of the desiccant bag. The desiccant removes moisture from the refrigerant while the pouch filters solid particles from the refrigerant.
[0016] The invention will be further described in conjunction with the appended drawings in which:-
Fig. 1 is a broken away perspective view of a fluid flow tube incorporating an adsorbent package in accordance with the present invention, wherein the adsorbent package is shown partially exploded;
Fig. 2 is cross-sectional view taken along the plane represented by the lines and arrows 2-2 of Fig. 1;
Fig. 3 is a top plan view of the adsorbent package shown in Fig. 1;
Fig. 4 is an exploded orthogonal view of another embodiment of an adsorbent package in accordance with the invention;
Fig. 5 is a magnified view of a portion of the adsorbent package shown in Fig. 4;
Fig. 6 is an orthogonal view of the adsorbent package shown in Fig. 4 but prior to insertion of the integral cap and filter structure therein;
Fig. 7 is an orthogonal view of another embodiment of an adsorbent package in accordance with the invention; and
Fig. 8 is a schematic, fragmentary view of a portion of an integral condenser-receiver with the adsorbent package of the invention positioned in the receiver portion of the assembly.
[0017] Referring initially to Fig. 1 of the drawings, a fluid flow tube of an air conditioning system, particularly an air conditioning system used in the automotive field, is illustrated generally at 10. The fluid flow tube 10 comprises a conventional canister 12 including a cylindrical side wall 14 and opposing first and second end walls 16 and 18 defining a sealed chamber 19. An inlet opening 20 is formed within the cylindrical side wall 14 proximate the second end wall 18. Likewise, an outlet opening 22 is formed within the side wall 14 proximate the first end wall 16. Both the inlet and outlet openings 20 and 22 are in fluid communication with the chamber 19.
[0018] Referring further to Figs. 1 and 2, the adsorbent package 24 of the present invention is received within the chamber 19 of the canister 12. The adsorbent package 24 includes a desiccant bag 26 having a pouch 28. The pouch 28 is formed from a fluid permeable material, preferably a non-woven spun bonded nylon as set forth above. More particularly, the pouch 28 is preferably made from a tubular sleeve of the spun bonded nylon material which has been cut into lengths and filled with an appropriate granular adsorbent material or desiccant 30.
[0019] A first end 32 of the pouch 28 is sealed along a seam 34. In the preferred embodiment, this end seam is formed by suitably tucking in a portion of the tube side wall and flattening an end portion under conditions which causes the spun bonded nylon material to fuse together and seal the end of the pouch 28. Preferably, the sealing is effected by use of an ultrasonic welding machine. However, RF and heat sealing methods can also be mentioned.
[0020] A second end 36 of the pouch 28 is substantially cylindrical and concentrically receives a filter cap 38. The filter cap 38, in turn, is concentrically received within the side wall 14 of the canister 12.
[0021] With reference now to Figs. 1-3, the filter cap 38 includes a body 40 preferably molded from a thermoplastic material. The preferred material is a polypropylene, however any similar soft pliable thermoplastic may be readily substituted therefor. The material selected should preferably tolerate temperatures within a range of -29° to 121°C (-20° to 250°F) and should be compatible with the particular refrigerant used in the air conditioning system.
[0022] The body 40 comprises a cylindrical side wall or skirt 42 supporting a porous end wall 44. The porous end wall 44 is preferably integrally molded with the cylindrical side wall 42 and includes a plurality of apertures 46 (Fig. 3). The apertures 46 are sized to have a diameter large enough to permit refrigerant flow therethrough but small enough to prevent passage of the desiccant 30. In an alternative embodiment of the present invention, the porous end wall 44 may comprise a screen material fixed to the side wall 42.
[0023] In the embodiment shown in Figs. 1-3, an attachment device, preferably an annular attachment ring 48, extends radially outwardly from the skirt and is slidably received within the pouch 28 for securing the desiccant bag 26 to the cap 38. In this embodiment of the invention, the pouch is ultrasonically welded to the attachment ring 48. It should be appreciated that other means of attachment, including heat, RF, and vibration welding may be readily substituted therefor. Alternatively, and as shown in Fig. 4, the pouch 28 may be secured to the cap 38 by means of a mechanical fastener, such as a snap ring.
[0024] A sealing rim or ring 50 extends radially outwardly from, and is preferably integrally formed with, the body 40 proximate the end wall 44. The sealing ring 50 is dimensioned to be concentrically received within and sealingly engage the cylindrical side wall 14 of the canister 12. As described above, the sealing ring 50 should be sufficiently resilient so as to provide sealing engagement with the canister side wall 14. sealing ring 50 provides a living seal to prevent refrigerant flow between the filter cap 38 and the side wall 14.
[0025] In operation, refrigerant enters the accumulator 10 through the inlet opening 20 of the canister 12 as indicated by arrow 52 in Fig. 2. The refrigerant is directed through the apertures 46 in the porous end wall 44 by the sealing ring 50. As may be appreciated, fluid flow is not permitted around the cap 38 due to the seal formed between the sealing ring 50 and the canister 12.
[0026] Refrigerant flows through the cap 38 and into the desiccant bag 26. Moisture is removed from the refrigerant by the desiccant 30 while solid particles are filtered by the pouch 28 and apertures 46. The treated refrigerant then exits the accumulator 10 through the outlet 22 in the canister 12 as indicated by arrow 54 in Fig. 2.
[0027] As may be appreciated, the present invention provides an adsorbent package 24 which efficiently removes moisture and filters solid particles from a refrigerant entering a fluid flow tube or canister structure such as an accumulator or receiver/drier.
[0028] Turning now to Figs. 4 and 5, there is shown another embodiment wherein an annular snap ring 102 is used to securely fasten the top of the pouch 28 to the cap 38. Here, attachment ring 48 is provided circumferentially around the body 40 of the cap. After the requisite amount of desiccant is supplied to the pouch, end 36 of the pouch 28 is slidably received over the attachment ring 48, Snap ring 102 having ridge 106 formed along its internal diameter is then slid up over the ridge or ring 48 to firmly lock the pouch within the grasp of the engaging ridge members 106, 48. In this manner, if desired, the pouch can be snugly secured to the cap without the need of a heat or ultrasonic sealing of the cap over the top portion of the pouch. As shown best in Fig. 5, the ridge 106 is directly axially above a ramp 109 or inclined surface to help ensure locking of the ridge 106 over the attachment ring 48 that is formed on the skirt of the cap member.
[0029] Fig. 6 shows the pouch of Fig. 4 in position prior to filling of the desiccant therein and, ipso facto, prior to insertion of the cap into the end 36 of the pouch and insertion of the snap ring 102 over the body 40 of the cap. It is noted here that both a longitudinal seam 702 and end seam 34 are provided in the strip of textile fabric to form the open ended tubular shaped pouch shown in the drawing. These seams, as aforementioned, are preferably formed by ultrasonic welding means, but other sealing methods may also be used.
[0030] Fig. 7 shows an adsorbent package in which the cap and associated filter are not used. This pouch is designed for snug, frictional engagement within the confines of a small diameter canister of the type normally encountered in the receiver/drier of an integrated condenser/receiver of the type described above and wherein one particular embodiment is shown in U.S. Patent 5,813,249. Here, in addition to seams 34 and 702, a top end seam 704 is provided to form the closed pouch structure.
[0031] Fig. 8 is a fragmentary schematic of an integrated condenser/receiver of the type shown in the '249 patent shown here with a small diameter adsorbent package of the invention disposed within the receiver. Here, condenser inlet tubes 502 communicate with the upstream section 520 of generally cylindrical header 504. The header is divided into two sections by partition 506. Inlet 508 provides communication for refrigerant flow from the condenser through the header 504 and into receiver 510. As is typical in some integral condenser receiver structures, the receiver is juxtaposed alongside the condenser header 504 and is directly connected thereto by welding, brazing, or other conventional joining techniques.
[0032] Quite typically, the diameter of the receiver canister is quite smallon the order of about 18 mm - 35 mm. This necessitates that the working diameter or interior area of the desiccant containing pouch should be such as to allow for adequate volume of desiccant material therein, and the interior diameter of the package should also allow for containment of a tracer dye wafer therein, without impeding the flow of the refrigerant containing fluid therethrough.
[0033] As shown in Fig. 8, the pouch 28 of the invention is snugly engaged within the confines of the receiver canister. Outlet 512 provides fluid communication between the downstream end 514 of the receiver and downstream section 522 of the header 504. The downstream section of the header communicates with supercooler tubes 530.
[0034] The Fig. 8 apparatus operates to permit condensed refrigerant flow from the condenser tubes 502 into the upstream section 520 of header 504. This condensed refrigerant, carrying oil, some moisture and possibly solids therein, flows into the upstream portion 591 of receiver 510 through inlet 508. The fluid mix then flows downstream as shown through the filter cap 38 and desiccant bag 28 into the downstream section 514 of the header and then into the supercooling unit.
[0035] As stated above, and contrary to prior indications, we have found that the pouch 28 is advantageously formed of non-woven spun bonded nylon material such us that sold under the previously mentioned PBN-I1 designation. This material is supplied in the thickness of from about 0.076 mm - 0.559 mm (3 mils.- 22 mils). At present, it is preferred to employ a thickness of about 0.38 mm (15 mils). This ensures adequate cross-sectional area permitting dye wafer insertion into the pouch and adequate desiccant volume and fluid permeation. Air permeability for this material reportedly ranges from about 30.5 m3/min/m2 (100 cfm/ft2) to about 420 m3/min/m2 (1380 cfm/ft2). Air permeability of the preferred 0.38 mm (15 mil) thickness is about 61 m3/min/m2 (200 cfm/ft2) to 91 m3/min/m2 (300 cfm/ft2).
1. A desiccant containing package (24) for use in a chamber (19) of an air conditioning
system, comprising an elongated pouch (28) for containing desiccant (30), said pouch
having a first (32) and a second (36) end portion, one (32) of which is sealed and
the other (36) of which sealingly receives a cap (38), and said cap comprising a body
including a skirt (42) and a sealing rim (50) extending outwardly from the body for
sealing the cap with the chamber, characterised in that the cap (38) comprises a filter surface (44) having a plurality of filter apertures
therein such that refrigerant flowing through the apertures in the filter surface
of the cap reaches desiccant contained in the pouch, and in that an attachment ring (48) is formed around the skirt and extends radially outwardly
therefrom and secures the desiccant pouch to the cap.
2. The desiccant containing package claimed in claim 1 wherein said other end portion
(36) of the pouch (28) is sealingly fused over the attachment ring (48).
3. The desiccant containing package claimed in claim 1 comprising a snap ring having
an internally facing ridge member (106), said other end portion (36) of the pouch
(28) being interposed between the attachment ring (48) and said ridge member and being
securely fastened to the cap (38) thereby.
4. The desiccant containing package claimed in claim 3 wherein said snap ring (102) comprises
an inclined surface adjacent the ridge member (106)
5. The desiccant containing package claimed in any preceding claim wherein the pouch
(28) is composed of a non-woven spun bonded nylon material.
6. The desiccant containing package claimed in any preceding claim wherein he cap (38)
comprise a generally cylindrical body.
1. Trockenmittel enthaltendes Paket (24) zur Verwendung in einer Kammer (19) eines Klimaanlagensystems,
welches einen lang gestreckten Beutel (28) zur Aufnahme von Trockenmittel (30) aufweist,
der Beutel weist ein erstes (32) und ein zweites (36) Endteil auf, wobei eines der
Enden (32) abgedichtet ist und das andere Ende (36) einen abdichtenden Deckel (36)
aufnimmt, worin der Deckel einen Körper aufweist, der einen Kragen (42) und einen
Dichtungsring (50) einschließt, welche sich von dem Körper nach außen erstrecken,
zur Abdichtung der Kammer mit dem Deckel, dadurch gekennzeichnet, dass der Deckel (38) eine Filteroberfläche (44) aufweist, welche eine Vielzahl von Filteröffnungen
darin aufweist, so dass Kühlmittel durch die Öffnungen in die Filteroberfläche des
Deckels fließt und das Trockenmittel erreicht, welches in dem Beutel eingeschlossen
ist, und worin ein Befestigungsring (48) um den Kragen gebildet ist, und sich radial
nach außen erstreckt, und den Trockenmittelbeutel mit dem Deckel verbindet.
2. Trockenmittel enthaltendes Paket nach Anspruch 1, worin das andere Endteil (36) des
Beutels (28) über den Befestigungsring (48) abdichtend gesichert ist.
3. Trockenmittel enthaltendes Paket nach Anspruch 1, welches einen Sprengring aufweist,
der ein nach innen gerichtetes Kantenteil (106) aufweist , das andere Endteil (36)
des Beutel (28) ist zwischen dem Befestigungsring (48) und dem Kantenteil eingefügt
und dadurch mit dem Deckel (38) fest verbunden.
4. Trockenmittel enthaltendes Paket nach Anspruch 3, worin der Sprengring (102) eine
angeschrägte Oberfläche aufweist, angrenzend an das Kantenteil (106) aufweist.
5. Trockenmittel enthaltendes Paket nach einem der vorhergehenden Ansprüche, worin der
Beutel (28) aus einem nicht verwebten "Spun-Bonding" Nylon Material gebildet ist.
6. Trockenmittel enthaltendes Paket nach einem der vorherhegenden Ansprüche, worin der
Deckel (38) einen im wesentlichen zylindrischen Körper aufweist.
1. Emballage contenant un dessicatif (24) destiné à être utilisé dans une chambre (19)
d'un système de climatisation d'air, comprenant une poche allongée (28) pour contenir
un dessicatif (30), ladite poche ayant une première (32) et une seconde (36) parties
d'extrémité, dont l'une (32) est fermée hermétiquement et dont l'autre (36) reçoit
de manière étanche un couvercle (38), et ledit couvercle comprenant un corps comportant
une collerette (42) et un rebord d'étanchéité (50) s'étendant vers l'extérieur depuis
le corps pour fermer hermétiquement le couvercle avec la chambre, caractérisé en ce que le couvercle (38) comprend une surface de filtre (44) ayant une pluralité d'ouvertures
de filtrage à l'intérieur de telle sorte que du réfrigérant s'écoulant à travers les
ouvertures dans la surface de filtre du couvercle atteint le dessicatif contenu dans
la poche, et en ce qu'une bague de fixation (48) est formée autour de la collerette et s'étend radialement
vers l'extérieur depuis celle-ci et fixe la poche de dessicatif au couvercle.
2. Emballage contenant un dessicatif selon la revendication 1 dans lequel ladite autre
partie d'extrémité (36) de la poche (28) est fusionnée de manière étanche sur la bague
de fixation (48).
3. Emballage contenant un dessicatif selon la revendication 1 comprenant un anneau élastique
ayant un élément d'arête faisant face de manière interne (106), ladite autre partie
d'extrémité (36) de la poche (28) étant interposée entre la bague de fixation (48)
et ledit élément d'arête et étant ainsi fixée de manière ferme au couvercle (38).
4. Emballage contenant un dessicatif selon la revendication 3 dans lequel ledit anneau
élastique (102) comprend une surface inclinée adjacente à l'élément d'arête (106)
.
5. Emballage contenant un dessicatif selon l'une quelconque des revendications précédentes
dans lequel la poche (28) est composée d'un matériau en nylon filé lié non tissé.
6. Emballage contenant un dessicatif selon l'une quelconque des revendications précédentes
dans lequel le couvercle (38) comprend un corps généralement cylindrique.