Refrigerant Distributor for Aluminum Coils

Abstract

A method and system are described for a refrigerant distributor, and for attaching the distributor tubes to an evaporator coil. A short tube can inserted into the bell end of a tube and the bell end can be crimped around the short tube to lock it into place. The short tube preferably has a bead or widened shaft around which to crimp the bell. The disclosure is particularly beneficial for aluminum based components because aluminum is more susceptible to blockages or leaking due to problems from brazing.

Claims

1. A refrigerant distributor for use in an HVAC system comprising: a housing, the housing comprising a plurality of inlets and a plurality of outlets; a plurality of tubes, the plurality of tubes connected to the plurality of outlets at one end and comprising a plurality of bells at a distal end; and a plurality of short tubes, the plurality of short tubes inserted into the plurality of bell; wherein the plurality of bells has been crimped around the short tube.

2. The refrigerant distributor of claim 1 wherein the plurality of short tubes comprises a bead and the plurality of bells are crimped around the bead.

3. The refrigerant distributor of claim 1 wherein the plurality of short tubes comprises a flare and the plurality of bells are crimped around the flare.

4. The refrigerant distributor of claim 1 wherein the plurality of short tubes comprises a sized-out end and the plurality of bells are crimped around the sized-out end.

5. The refrigerant distributor of claim 1 wherein the refrigerant distributor comprises aluminum.

6. The refrigerant distributor of claim 1 wherein the plurality of bells are formed by sizing out the plurality of tubes.

7. The refrigerant distributor of claim 1 wherein the plurality of bells are brazed onto the plurality of tubes.

8. The refrigerant distributor of claim 1 wherein the housing comprises an inlet on one end and the plurality of outlets on a distal end, the housing further comprising a threaded portion around the inlet.

9. A refrigerant distributor tube for connecting a refrigerant distributor housing to an evaporator coil, the refrigerant distributor tube comprising: a first end configured to be coupled to a refrigerant distributor housing; a distal end comprising a bell; and a short tube inserted into the bell; wherein the bell has been crimped around the short tube.

10. The refrigerant distributor tube of claim 9 wherein the short tube comprises a bead and the bell is crimped around the bead.

11. The refrigerant distributor tube of claim 9 wherein the short tube comprises a flare and the bell is crimped around the flare.

12. The refrigerant distributor tube of claim 9 wherein the short tube comprises a sized-out end and the bell is crimped around the sized-out end.

13. The refrigerant distributor tube of claim 9 wherein the refrigerant distributor tube comprises aluminum.

14. The refrigerant distributor tube of claim 9 wherein the bell is formed by sizing out the refrigerant distributor tube.

15. The refrigerant distributor tube of claim 9 wherein the bell is brazed onto the tube.

16. The refrigerant distributor tube of claim 9 wherein the short tube is brazed into the bell.

17. A method of constructing a refrigerant distributor comprising: providing a housing, the housing comprising a plurality of inlets and a plurality of outlets; attaching a plurality of tubes to the plurality of outlets; sizing out a distal end of the plurality of tubes to form a plurality of bells; inserting a plurality of short tubes into the plurality of bells; and crimping a portion of the plurality of bells about the plurality of short tubes.

18. The method of claim 17 wherein the plurality of short tubes comprise a bead and the plurality of bells are crimped around the bead.

19. The method of claim 17 wherein the housing, plurality of tubes, and plurality of short tubes comprise aluminum.

20. The method of claim 17 further comprising forming threads on an exterior portion of the housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

[0008] FIGS. 1A-1B show a diagram of a prior art refrigerant distributor and HVAC coil.

[0009] FIG. 2 shows a diagram of a refrigerant distributor under the present disclosure.

[0010] FIGS. 3A-3C show diagrams of refrigerant distributor tubes under the present disclosure.

[0011] FIG. 4 shows a diagram of a refrigerant distributor tube under the present disclosure.

[0012] FIG. 5 shows a diagram of a refrigerant distributor tube under the present disclosure.

[0013] FIG. 6 shows a flow-chart diagram of a method embodiment under the present disclosure.

[0014] FIG. 7 shows a flow-chart diagram of a method embodiment under the present disclosure.

[0015] FIG. 8 shows a flow-chart diagram of a method embodiment under the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0016] Evaporator coils in HVAC systems are typically made of copper or aluminum (though other materials can be used as well). Copper-based coils have been more popular previously, but more and more aluminum is being used. When an evaporator is copper, it has been preferred to use a copper refrigerant distributor. Refrigerant distributors 10, such as that seen in FIGS. 1A-1B, comprise a threaded housing 12 at one end and a plurality of tubes 13 at the other end which connect to the inlets 51 of an evaporator coil(s) 50. The tubes will have a bell-shaped end 14. The bell can either be formed by sizing out the tube 13 or by brazing the bell 14 onto the tube 13, such as at a brazing point 15. When the tubes 13 are attached to the inlets 51, brazing will be done again to attach bells 14 to the inlets 51. Multiple brazings are unproblematic when the distributor 10, tubes 13, and coil 50 are all made of copper. This is because the melting temperature of the brazing alloy is sufficiently lower than that of copper. However, this process is problematic when using aluminum-based distributors and coils. Aluminum's lower melting temperature has led to problems where the tube/bell/inlet breaks and begins to leak or block a refrigerant path. Using aluminum is especially problematic when sizing out the bell portion of a distributor tube. The sizing out process creates a thin material that is susceptible to problems during brazing. A process or system is needed by which aluminum can be more effectively integrated into distributors and coils.

[0017] A refrigerant distributor under the present disclosure, such as in FIG. 2, can comprise a short tube 220 attached within a sized out bell 214 on a distributor tube 213, the short tube 220 being attached to the distributor tube 213 by a crimping process at the bell 214. The bell 214 can then be brazed onto an HVAC coil. This is advantageous over the prior art because the system undergoes only one brazing process, instead of two brazing processes. The prior art used brazing to attach a bell to a tube, and a second brazing process to attach the bell to a heat exchanger/coil. Furthermore, short tube 220 provides extra structural reinforcement between the refrigerant distributor and the coil (or other HVAC component).

[0018] The possible embodiment in FIG. 2 comprises a refrigerant distributor 210. Refrigerant distributor 210 comprises a threaded housing 212, tubes 213, bells 214, and short tubes 220. Bells 214 comprise a crimping section 218. The unseen ends of short tubes 220 are attached within bells 214 via crimping at section 218. In a preferred embodiment short tubes 220 are similarly sized to tubes 213 but are separate tubes.

[0019] Possible embodiments of bells and short tubes under the present disclosure can be seen in FIGS. 3A to 3C. Tubes 13 have undergone a sizing out process to create a bell-shaped end 314. Short tubes 320 have been inserted into bells 314. Each embodiment has a different shape pattern. FIG. 3A shows a short tube 320 with a bead 370. FIG. 3B shows a short tube 320 with a flare 380. FIG. 3C shows a short tube 320 with a sized end 390. Other patterns or shapes can be used, as long as a surface is provided against which crimping can provide a tight fit. Crimping 318 is completed after insertion of the short tube 314. After construction, the distributor tubes 313 can then be brazed onto the inlets of an evaporator coil(s). The extra strength provided by the short tube 320, and its position within the bell 314, allows the tube 313 to withstand the temperatures of a brazing process. A preferred embodiment of tubes 313 and short tubes 320 comprises aluminum parts. However, any material can be used that would be appropriate for use in evaporator coils and distributor tubes.

[0020] An alternative embodiment of the distributor tube under the present disclosure can be seen in FIG. 4. In this embodiment, tube 413 has a sized-out bell 414 and a short tube 420 inserted therein. Short tube 420 is brazed at brazing ring 460 to the inside of bell 414. An embodiment such as this would generally not be used for aluminum components, but would be useful for copper or stainless steel embodiments.

[0021] Whatever material (e.g. steel, copper, aluminum) is used for an evaporator coil, generally the same material will be used for the distributor tubes. During use, coils and tubes can degrade and corrode. Typically, users and manufacturers try to avoid the mixing of different materials from corrosion (e.g. aluminum and copper). Instead, if there is corrosion it is desirable to have just one material.

[0022] As described, the bells 314 and 414 in FIGS. 3 and 4 have been formed by a sizing out process. That is a preferred embodiment. Other embodiments can use brazing, soldering, adhesive, or any appropriate mechanism.

[0023] FIG. 5 displays another embodiment under the present disclosure. In this embodiment tube 513 has a bell 514 and a short tube 520 that has been crimped into placed around bead 570. In addition, a shell 555 is provided that extends around the bell 514 and short tube 520. The shell 555 can be brazed onto the coil inlet or can be crimped around the bell 514 and/or short tube 520. Crimping or brazing of the shell 555 can be done on either side of the bell 514, or both sides.

[0024] FIG. 6 displays a possible method embodiment 600 under the present disclosure for constructing a brazing resistant distributor tube. At 610, a refrigerant distributor tube is provided. At 620, an end of the tube is sized out to create a bell. At 630, a short tube is provided with a beaded end. At 640, the beaded end is inserted into the bell. At 650, the bell is crimped around the beaded end to seal the beaded end into the bell.

[0025] FIG. 7 displays another possible method embodiment 700 under the present disclosure for constructing an HVAC system. At 710, an evaporator coil is provided. At 720, a refrigerant distributor is provided comprising a housing and a plurality of tubes. At 730, an end of at least one of the plurality of tubes is sized out to form a bell. At 740, a short tube is provided with a beaded end. At 750, the beaded end is inserted into the bell. At 760, the bell is crimped around the beaded end. At 770, the short tube is inserted into an inlet on the evaporator coil. At 780, the bell is brazed onto the evaporator coil inlet.

[0026] FIG. 8 displays another possible method embodiment 800 under the present disclosure, for constructing a refrigerant distributor. At 810, a housing is provided with a plurality of inlets and a plurality of outlets. At 820, a plurality of tubes is attached to the plurality of outlets. At 830, a distal end of the plurality of tubes is sized out to create a plurality of bells. At 840, a plurality of short tubes is inserted into the plurality of bells. At 850, a portion of the plurality of bells is crimped about the plurality of short tubes.

[0027] Although the present disclosure has been described with regard to aluminum coils and tubes, the same principles can be applied to components of other materials as well. Furthermore, the principles can be applied to connections between various components within an HVAC system, not just between a refrigerant distributor and an evaporator coil. Connections to condenser, compressors, coils, and other components can take advantage of the present disclosure.

[0028] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.