Compressor air cooler with replaceable flange ring

Abstract

A cooler assembly includes a substantially hollow casing having an inside surface having a diameter D. A flange ring is positioned in the casing and has a flange ring outside surface sealingly secured against the casing inside surface. The flange ring has a flange ring inside surface having a diameter r less than the diameter D. A cooler is positioned in the casing and has first and second headers and a plurality of cooling tubes extending therebetween. At least the first header has a first header outside diameter I that is approximately equal to or slightly less than the diameter r. The cooler is positioned such that the first header is axially aligned with and sealed against the flange ring.

Description

CROSS REFERENCE TO OTHER APPLICATIONS

This application claims priority under 35 U.S.C. sec. 119 to provisional patent application Ser. No. 60/592,639, filed on Jul. 30, 2004, which is hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to an air cooler assembly for a compressor. More particularly, the present invention relates to an air cooler assembly including a replaceable flange ring.

BACKGROUND

Many applications, for example, a centrifugal compressor, utilize an air cooler positioned within a casing to cool air flowing through the cooler. An example of such a prior art air cooler assembly 2 is shown in FIGS. 1 and 2. The air cooler 2 assembly generally comprises a casing 4, a removable cooler 30 and a removable cover 20. The casing 4 is generally a hollow tube with an inlet end 6 and an outlet end 8. In a centrifugal compressor application, the inlet end 6 is configured for connection adjacent the compressor impeller (not shown) such that the compressed air is received in the air cooler assembly inlet 9. A shoulder 10 is typically provided at the inlet end 6 to define an axial stop for the removable cooler 30. The outlet end 8 of the casing 4 has an opening 11 sufficiently large to allow the cooler 30 to be inserted therethrough. Once the cooler 30 is inserted, the cover 20 is secured to the casing 4 to retain the cooler in position.

The cooler 30 generally comprises an inlet header 32 and an outlet header 34 with numerous cooler tubes 36 between the two headers 32, 34. In operation, cooling water or the other cooling fluid flows through the casing 4 through casing inlet and outlet 5 and 7 and around the cooling tubes 36. Air entering the casing inlet 9 travels through the tubes 36 and transfers heat to the cooling fluid circulating about the tubes 36. The headers 32, 34 provide the cooler tube 36 spacing and structural support for the cooler 30, but also must provide the cooling fluid to air sealing. In this regard, each of the headers 32, 34 is configured to seal against the inside surface 14 of the casing 4 at sealing areas 16 and 18, respectively.

As the coolers 30 are used in the compressor or another application, problems may develop. The casing inner surface 14 typically develops voids due to water corrosion. Since correct sealing is generally dependent on the smooth mating surfaces of the header and the casing, the voids diminish the ability of the cooler headers 32, 34 to properly seal the water from the air.

Additionally, during maintenance of the compressor or other application, it is at times necessary to remove the cooler 30 from the casing 4. If the cooler 30 is used with water filled with particulate (dirt), often this dirt builds up between the cooler 30 and the casing inner surface 14. When the cooler 30 is removed through the opening 11 in the outlet end 8, the inlet header 32 acts as a scraper and tries to pull the dirt out with the cooler 30. The dirt often causes the cooler 30 to become “stuck” and makes the cooler 30 removal very difficult and/or damages the cooler 30 as it is removed.

SUMMARY OF THE INVENTION

The present invention provides a cooler assembly comprising a substantially hollow casing having casing inside surface having a diameter D. A flange ring is positioned in the casing and has a flange ring outside surface sealingly secured against the casing inside surface. The flange ring has a flange ring inside surface having a diameter r less than the diameter D. A cooler is positioned in the casing and has first and second headers and a plurality of cooling tubes extending therebetween. At least the first header has a first header outside diameter I that is approximately equal to or slightly less than the diameter r. Since the diameter r, and thereby the diameter I, is less than the diameter D, the first header is clear of casing inside surface. The cooler is positioned such that the first header is axially aligned with and sealed against the flange ring.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a prior art air cooler assembly.

FIG. 2 is a cross sectional view of the prior art air cooler assembly of FIG. 1.

FIG. 3 is a cross sectional view of an air cooler assembly that is a first embodiment of the present invention.

FIG. 4 is a cross sectional view of a flange ring of the air cooler assembly of FIG. 3.

FIG. 5 is an exploded view of a portion of the flange ring as indicated by the circle 5 in FIG. 4.

FIG. 6 is an exploded view of a portion of the air cooler assembly as indicated by the circle 6 in FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be described with reference to the accompanying drawing figures wherein like numbers represent like elements throughout. Certain terminology, for example, “top”, “bottom”, “right”, “left”, “front”, “frontward”, “forward”, “back”, “rear” and “rearward”, is used in the following description for relative descriptive clarity only and is not intended to be limiting.

Referring to FIG. 3, an air cooler assembly 40 that is a first embodiment of the present invention is shown. The air cooler assembly 40 generally includes a casing 4, a removable cover 20, a removable cooler 40, and a flange ring 50. The casing 4 is a generally hollow tube with an inlet end 6 and an outlet end 8 and an inside surface 14 having a diameter D. A shoulder 10 is defined inside the casing 4 adjacent to the inlet end 6 to define at least a first area of reduced diameter d. The cover 20 is removably connected to the casing 4 to close the opening 11.

The cooler 41 has an inlet header 42 and an outlet header 44 with a plurality of cooling tubes 46 (only two shown for clarity) extending therebetween. Flow through the cooling tubes 46 is substantially as described with respect to the prior art cooler assembly 2. In the present embodiment, the inlet header 42 has an outside diameter I that is less than the inside diameter D of the casing 4 and the outlet header 44 has an outside diameter O that is approximately equal to the inside diameter D of the casing 4. As such, the outlet header 44 is configured to seal against the inside surface 14 of the casing 4 at seal area 18. O-rings or the like can be utilized to assist in sealing between the outlet header 44 and the casing inside surface 14.

The inlet header 42 does not seal against the casing inside surface 14, but instead is clear of the casing inside surface 14. As such, when the cooler 41 is removed from the casing 4 through opening 11, the inlet header 42 does not scrape against the casing inside surface 14. Even in the event of dirt build up, the inlet header 42 is fairly easily removed from the casing 4.

To facilitate sealing of the inlet header 42 in the inlet sealing area 16, a flange ring 50 is sealingly bonded within the casing 4 adjacent to the shoulder 10. Referring to FIGS. 4 and 5, the preferred flange ring 50 will be described. The flange ring 50 has a hollow cylindrical body 52 having an outside surface 54 with a diameter R approximately equal to or slightly less than the inside diameter D of the casing 4. In the present embodiment, the casing 4 and flange ring body 52 are described as cylindrical, however, they may have other complementary shapes. For example, the casing 4 may have a square configuration, with the flange ring 50 having a complementary square configuration. The flange ring 50 is preferably manufactured from a rust resistant metal, but may be manufactured from other materials, including other metals and non-metals.

The flange ring body 52 preferably has a chamfered surface 56 along the outside surface 54 at the inlet side of the flange ring 50 to assist in the insertion of the flange ring 50 into the casing 4. The outside surface 54 also may include one or more circumferential grooves 58 to assist in bonding the flange ring 50 within the casing as will be described in greater detail hereinafter. The flange ring 50 has an inside surface 62 having an inside diameter r that is approximately equal to or slightly larger than the outside diameter I of the inlet header 42. A radial shoulder 60 extends radially inward of the inside surface 62 to define an axial stop for the inlet header 42. In the installed position (see FIG. 6), the radial shoulder 60 is preferably backed up by the casing shoulder 10. The inside surface 62 also preferably has a radially outward lead-in chamfer 64 adjacent the outlet side of the flange ring 50. The lead-in chamfer 64 assists in insertion of the inlet header 42 of the cooler into the flange ring 50.

Sealing of the inlet header 42 will be described in detail with reference to FIGS. 3 and 6. The flange ring 50 is sealed against the casing inside surface 14 at the sealing area 16 using a removable high temperature sealant 70. An illustrative sealant is Superflex™ Blue RTV sealant manufactured by Loctite. The sealant 70 is preferably a material that is initially flexible and then cures after a given time. As such, when the sealant 70 is applied, the sealant 70 will fill any voids that may have developed in the sealing area 16 of the casing 4 to allow for proper sealing. The flange ring 50 preferably has a width W that is greater than the sealing width w of a standard header (see FIG. 3). As such, the flange ring 50 covers and fills the voids of a larger area. The cured material may still have some flexibility, but securely bonds the flange ring 50 within the casing 4. As shown in FIG. 6, the sealant 70 fills the circumferential grooves 58 to help secure the flange ring 50 against axial movement.

Once the flange ring 50 is secured within the casing 4, the cooler 41 is inserted in to casing 4 through the opening 11. The lead-in chamfer 64 assists in directing the inlet header 42 in to the flange ring 50. The inlet header 42 preferably has an inlet side shoulder 47 configured to seat against the flange shoulder 60. To facilitate the seal between the replaceable flange ring 50 and the smaller diameter inlet header 42, the inlet header 42 has a circumferential groove 43 along its outside surface configured to receive an o-ring 45 or the like. The o-ring 45 seals between the inlet header 42 and the flange ring inside surface 62. In the event the flange ring 50 were to corrode and compromise this seal, the flange ring 50 can easily be removed and replaced. Additionally, as explained above, the inlet header diameter I being less than the casing inside diameter D allows the cooler 41 to be easily removed without any scraping or wedging within the casing 4.

While the outlet header 44 of the preferred embodiment is described as having an outer diameter O that is substantially equal to the casing inside diameter D and is sealed directly to the casing inside surface 14, it is possible to provide a flange ring (not shown) at the sealing area 18 and to manufacture the outlet header 44 similar to the inlet header 42. The flange ring in this instance would preferably not have a radial shoulder, but would still act to fill any voids that may have developed in the sealing area 18.

Claims

1. A cooler assembly comprising:

a substantially hollow casing having an inside surface having a diameter D;

a flange ring positioned in the casing and having an outside surface sealingly secured against the casing inside surface, the flange ring having an inside surface having a diameter r less than the diameter D; and

a cooler positioned in the casing and having a first header, a second header, and a plurality of cooling tubes extending therebetween, wherein the first header has a first header outside diameter I that is approximately equal to or slightly less than the diameter r, the cooler is positioned such that the first header is axially aligned with and sealed against the flange ring, and the cooler is insertable in and removable from the casing independently of the flange ring.

2. The cooler assembly of claim 1, wherein the flange ring includes a ring shoulder that extends radially inward from the flange ring inside surface to define an axial stop for the first header.

3. The cooler assembly of claim 1, wherein the casing further includes a shoulder that extends radially inward from the casing inside surface, wherein the shoulder defines an axial stop for the flange ring.

4. The cooler assembly of claim 1, wherein the flange ring has a width W and the first header has a width less than the width W.

5. The cooler assembly of claim 1, wherein the flange ring outside surface has a chamfered portion to assist in the insertion of the flange ring into the casing.

6. The cooler assembly of claim 1, wherein the flange ring inside surface has a chamfered portion to assist in the insertion of the first header into the flange ring.

7. The cooler assembly of claim 1, wherein the flange ring outside surface has at least one substantially circumferential groove to assist in bonding the flange ring to the casing.

8. The cooler assembly of claim 1, further including an O-ring between flange ring and the first header.

9. The cooler assembly of claim 8, wherein the first header includes an outside surface having a groove configured to receive the O-ring.

10. The cooler assembly of claim 1, wherein the flange ring is sealed to the casing with a high temperature sealant.

11. A cooler assembly comprising:

a substantially hollow casing having an inside surface having a diameter D and including a casing shoulder that extends radially inward from the casing inside surface;

a flange ring positioned in the casing against the casing shoulder and having an outside surface sealingly secured against the casing inside surface, the flange ring having an inside surface having a diameter r less than the diameter D and having a ring shoulder that extends radially inward from the flange ring inside surface; and

a cooler positioned in the casing and having a first header and a second header and a plurality of cooling tubes extending therebetween, wherein the first header has a first header outside diameter I that is approximately equal to or slightly less than the diameter r, the cooler is positioned such that the first header is axially aligned with and sealed against the flange ring, the ring shoulder defines an axial stop for the first header, and the cooler is insertable in and removable from the casing independently of the flange ring.

12. The cooler assembly of claim 11, wherein the flange ring has a width W and the first header has a width less than the width W.

13. The cooler assembly of claim 11, wherein the flange ring outside surface has a chamfered portion to assist in the insertion of the flange ring into the casing.

14. The cooler assembly of claim 11, wherein the flange ring inside surface has a chamfered portion to assist in the insertion of the first header into the flange ring.

15. The cooler assembly of claim 11, wherein the flange ring outside surface has at least one substantially circumferential groove to assist in bonding the flange ring to the casing.

16. The cooler assembly of claim 11, further including an O-ring between flange ring and the first header.

17. The cooler assembly of claim 16, wherein the first header includes an outside surface having a groove configured to receive the O-ring.

18. The cooler assembly of claim 1, wherein the flange ring is sealed to the casing with a high temperature sealant.

19. A method for assembling a cooler assembly, the method comprising:

providing a substantially hollow casing having a casing inside surface defining a casing shoulder;

applying a high temperature sealant at least partially covering the casing inside surface and the casing shoulder;

inserting a flange ring into the casing and against the casing shoulder, wherein the flange ring includes an outside surface, an inside surface, a ring shoulder that extends radially inward from the flange ring inside surface;

inserting a cooler into the casing, wherein the cooler includes a first header, a second header and a plurality of cooling tubes extending therebetween, such that the first header is axially aligned with and sealed against the flange ring and the ring shoulder defines an axial stop for the first header; and

curing the sealant.