United States Patent 3835918

A base containing a pair of identical heat exchangers, demisters and separators has rigidly mounted thereon a cast multi-stage compressor casing provided with integral air inlet and discharge passages in direct communication with corresponding passages in the top wall of the base for providing the intercooling between stages. Fluid passes through the intercoolers by moving downwardly through the heat exchangers, downwardly through restricted nozzles and reversely upwardly for separating condensation, upwardly through the demisters and through central partition walls forming central manifold chambers. The liquid connections for the intercoolers may be uncoupled at one end for sliding the intercoolers off shelves from the opposite end. A telescopic resilient coupling between the casing inlet to the rotor and an inlet housing rigidly coupled to a fluid supply will prevent transmission of forces therebetween. The base further mounts the drive structure for the compressor and carries an oil sump below the drive structure.

Application Number:
Publication Date:
Filing Date:
Primary Class:
Other Classes:
55/315.2, 55/320, 55/434, 62/93, 165/119, 415/179
International Classes:
F04D29/58; (IPC1-7): F04D29/58; F04C29/04; F04D17/08
Field of Search:
415/179 62
View Patent Images:
US Patent References:
3541807AIR DRYING DEVICE1970-11-24Henderson
3453809AIR DRYING UNIT1969-07-08Henderson
3001692Multistage compressors1961-09-26Schierl

Primary Examiner:
Davis Jr., Albert W.
Attorney, Agent or Firm:
Curtin, Raymond J.
Parent Case Data:

This application is a division of patent application Ser. No. 44,034 entitled "Compressor Base And Intercoolers", Karol Pilarczyk, inventor, filed June 8, 1970.
What is claimed is

1. A compressor intercooler, comprising: wall means forming an intercooler chamber having a fluid inlet adjacent its upper end and a fluid outlet adjacent its lower end; gas-liquid heat exchanger means mounted in said intercooler chamber in fluid communication between said inlet and said outlet; demister means mounted in said intercooler chamber in fluid communication between said heat exchanger means and said outlet; condensate separator means mounted in said intercooler chamber in fluid communication between said heat exchanger means and said demister means, and baffle means mounted in said intercooler chamber for directing fluid downwardly through said heat exchanger means, downwardly through a restricted nozzle passage partially forming said condensate separator means and reversely upwardly through said demister means whereby the flow of said fluid will be accelerated and reversed to separate condensate droplets therefrom.

2. The compressor intercooler of claim 1, wherein said wall means include first opposed sides and second opposed sides and said baffle means including a plate extending completely between said first opposed sides of said intercooler chamber, downwardly from one of said second opposed sides to closely adjacent the other of said second opposed sides of said intercooler chamber between said demister means and said heat exchanger means, and then substantially vertically downwardly to below said demister means adjacent said other of said second opposed sides.

3. A compressor base, comprising: a top wall, a bottom wall, two opposed first side walls and two opposed second side walls forming a main substantially closed chamber; partition walls parallel to each other and parallel to said first side walls extending between said second side walls forming therebetween two substantially identical intercooler chambers and an intermediate manifold chamber; and at least one additional partition wall substantially parallel to said second side walls subdividing said manifold chamber into at least two manifold subchambers.

4. The compressor base of claim 3, including inlet fluid passage means extending through said top wall into one of said intercooler chambers and through said top wall into the other of said intercooler chambers; fluid interconnecting passage means in one of said partition walls extending from one of said intercooler chambers into one of said manifold subchambers, and additional fluid interconnecting passage means in another of said partition walls extending from the other of said intercooler chambers into another of said manifold subchambers; and fluid passage means extending through said top wall separately into each of said manifold subchambers.

5. The compressor base of claim 3, including another additional partition wall further dividing said manifold chamber to obtain three aligned manifold subchambers with the two outer manifold subchambers being in fluid communication with only one of said intercooler chambers and the intermediate manifold subchamber being in fluid communication with only the other of said intercooler chambers.


Intercooler structure has heretofore been one of the largest components of a multi-stage compressor, which not only increases the cost of the compressor but of more importance increases the space required for mounting the compressor unit. The intercooler structure of the patent to Schierl, U.S. Pat. No. 3,001,692, issued Sept. 26, 1961, overcomes some of the problems in the prior art but still employs a rather large base in comparison to the size of the heat exchangers used and employs a considerable amount of piping between stages and waste space within the base.

The air connections for the Olmstead et al. patent, U.S. Pat. No. 2,849,960, issued Sept. 2, 1958, have advantages with respect to force transmittal, but present a rather complicated structure that must be assembled at the use location and does not provide any rigid support for the adjacent piping extending away from the pump.


The features of the invention of this application may be used in combination with the features of the inventions in applicant's following related applications of the same filing date and assignee as the present application, the disclosures of which are incorporated herein in their entirety by reference: "Compressor Barrel Assembly", Ser. No. 44,446; "Compressor Power Recovery", Ser. No. 44,463; "Interchangeable Compressor Drive", Ser. No. 44,403; "Variable Capacity Compressor" Ser. No. 44,263.


Further objects, features and advantages in the present invention will become more clear from the following detailed description of a preferred embodiment as shown in the attached drawing, in which:

FIG. 1 is a perspective view of a multi-stage centrifugal compressor;

FIG. 2 is a schematic flow diagram showing the relationship of the compressor stages and intercoolers;

FIG. 3 is a partial cross-section side elevation view, with the cross-sections being taken in a vertical plane passing through the axes of rotation of the compressor rotor and drive assembly;

FIG. 4 is a partial cross-section and exploded view of a portion of the structure as shown in FIG. 1; and

FIG. 5 is a cross-sectional view taken on line 5--5 in FIG. 3 showing the air discharge manifold of the intercoolers.


The base 1 as shown in FIG. 1 has mounted rigidly thereon an fluid inlet housing 2 by means of a plurality of bolts (not shown) passing through bolt holes 3, a one-piece cast compressor casing 4 by means of a plurality of bolts 5, a gear housing 6 by means of a plurality of bolts 7, an electric drive motor 8 by means of resilient pads 9, and a control pannel 10 by any conventional means.

The inlet housing 2 is provided with an annular flange 11 provided with a plurality of peripherally arranged holes 12 for rigidly securing thereto an inlet fluid pipe when assembling the compressor at the use location. An upwardly extending integral mounting arm 13 is provided on the flange 11 for mounting thereto by means of bolts, or the like, a support bracket 14 that carries the diaphram control mechanism 15 of an inlet valve member 16, with the interposition of a suitable linkage 17. The inlet valve mechanism 15, 16, 17 is conventional per se for throttling the inlet fluid on partial load and for density control in a known manner. The diaphram control is provided with a pressure feedback tube 18 for this purpose. The multi-stage impeller rotor and fluid guide structure is contained within the one piece cast casing 4, which casing is provided with an axially through cylindrical bore 19, a downwardly facing planar surface 20 engaging the correspondingly planar upper surface of the top wall 21 of the base 1, and with an upwardly extending boss 22 that is bored for fluid communication with the outlet of the last compressor stage. As will be described later, a resilient coupling for vibration and load isolation is provided between the fluid inlet housing 2 and the compressor casing 4.

The drive assembly for the compressor may be of any type, but preferably employs the electric motor 8 that drives a gear set within the gear housing 6. Particularly, the drive structure may be of the type mentioned in one of applicant's previously identified applications wherein the structure is set forth in detail.

Welded steel fabrication is used for constructing the base 1, preferably from stock sheet and plate steel. The front wall 23 is provided with oppositely opening doors 24, which lead to a control and auxiliary component compartment having therein the inlet and outlet water couplings for the intercoolers. The supply 25 and outlet 26 water pipes for the intercoolers extend permanently through the side wall 27 and are provided at their outer ends with suitable couplings to be connected during installation at the site of use.

The basic fluid flow for the compressor is shown in FIG. 2 wherein the impeller of a first stage 28 passes fluid downwardly through a first intercooler 29. Thereafter, the fluid passes through the second stage impeller 30, which directs it downwardly through the second intercooler 31. Finally, the fluid passes upwardly and through the third stage impeller 32 for discharge to the point of use. The impellers 28, 32, 30 form an integral rotor drivingly connected with a spur helical pinion gear 33 that is driven by means of a drive helical gear 34 mounted on a parallel axis gear drive input shaft 35.

The inlet connection is shown in more detail in FIG. 3. A cylindrical mounting portion 36 of the inlet housing 2 is telescopically received over a cylindrical mounting portion 37 with the interposition of an O-ring 38. From the drawing, it is seen that the adjacent cylindrical surfaces of mounting portions 36, 37 are radially spaced from each other so that the O-ring 38 provides the only engaging connection between the inlet housing 2 and the compressor casing 4, while sealing these structures. Thus, the inlet housing 2 is independently supported on the base 1 to prevent transmittal of inlet housing vibration, canting, axial movement, radial movement and rotational movement to the compressor casing 4. Thus, the complete compressor may be supplied to a user and the user may rigidly couple his inlet fluid pipes directly to the inlet housing 2, without fear that forces relating to the coupling and inlet pipes will be transmitted to the compressor casing. Further, the stresses due to tightening of the connections between the inlet casing and fluid supply pipes will not be transferred to the compressor casing.

The removable barrel structure of the compressor includes separate shrouds, diffusers, and annular fluid guide elements all received in a stacked relationship within the cylindrical bore 19 of the one piece compressor casing 4. The compressor casing 4 is provided with integrally cast passages extending between the barrel assembly and the base 1. Particularly, a first passage 39 extends between the bore 19 and the planar surface 20 to conduct fluid from the discharge of the first stage, second passage 40 extends from the bore 19 to the planar surface 20 to conduct the fluid into the third stage inlet, third passage 41 extends from the bore 19 to the planar surface 20 to conduct fluid discharged from the second stage and fourth passage 42 extends from the bore 19 to the planar surface 20 to conduct fluid to the inlet of the second stage. The base 1 is provided with a top wall 21, opposed side walls 27 and 43, opposed front and back walls 23 and 44, and a bottom wall 45, which together form a substantially closed main chamber containing the intercooler structure. The top wall 21 is provided with a plurality of passages, also shown in FIG. 4, extending between the passages 39-42 and the intercooler main chamber. Particularly, the top plate 21 is provided with holes 46 that align with passages 39, holes 47 that align with passage 42, hole 48 that aligns with passage 40 and hole 49 that aligns with passage 41.

Two parallel partition walls 50, which are parallel to the walls 27, 43, extend completely from the top wall 21 to the bottom wall 45 and extend from the front wall 23 to the back wall 44 to form a central manifold chamber 51. Additional partition walls 52 subdivide the manifold chamber into three aligned subchambers, with the outside subchambers 53 being in fluid communication between the holes 47 in the top wall and correspondingly aligned holes in the left-hand partition wall 50, and with the inside subchamber 54 being in fluid communication between the hole 48 and a hole 55 in the right-hand partition wall 50 as shown in FIG. 3. In this manner, the main intercooler chamber is further divided into a first intercooler chamber 55 to the left of the partition walls 50 and a second intercooler chamber 56 to the right of the partition walls 50, as seen in FIG. 3. Identical and interchangeable parallel tube fluid heat exchangers 57 are mounted on shelves 58 within their respective intercooler chambers 55, 56 so that they may be horizontally slid into and out of the base 1 after the releasably secure back wall 44 is removed. For this purpose, the pipes 25, 26 are provided with releasable couplings 59 for uncoupling the heat exchangers, without affecting the location of the pipes 25, 26.

It is seen from FIG. 3, that fluid discharged respectively from the first stage and the second stage will pass through passages 39, 41 and holes 46, 49 downwardly into intercooler chambers 55, 56 to pass through their corresponding heat exchangers 57. Thereafter, the thus cooled fluid will be directed by baffle plates 60 through vertically extending restricted nozzle type passages 61 where the flow of fluid will approach sonic velocity. The high speed fluid then passes through a sharp acute angle and upwardly through demisters 62. Thus, it is seen that the baffles 60 formed in the nozzle type passages 61 constitute separators that will take the cooled fluid from the heat exchangers having condensed droplets therein, accelerate this cooled fluid and substantially reverse the flow of the accelerated cooled fluid to separate the condensate. Further, moisture will be removed from this separated fluid by means of demister 62. Thereafter, the relatively dry fluid will pass through respective holes in the partition walls 50 so that the fluid from the intercooler chamber 55 will pass into the submanifold chambers 53 and fluid from the intercooler 56 will pass into the submanifold chamber 54. It is noted that the left-hand passage 61 is substantially larger than the right-hand passage 61 as shown in FIG. 3, which difference is proportional to the difference in volume of fluid handled by the two intercoolers due to compression. For this same reason, two submanifold chambers 53 are provided for returning fluid to the second stage, while only one submanifold chamber is provided for returning fluid to the third stage.

Beneath the drive assembly 8, 6, the base 1 is provided with an oil sump 63, which is in direct communication with the interior of the gear housing 6.

From the above, it is seen that the compressor base of the present invention separately and rigidly mounts a rigid compressor casing and a rigid fluid inlet casing, and provides a telescopic coupling therebetween having only a flexible interengagement by means of the O-ring 38. With this coupling, the user's rigid fluid inlet pipes may be rigidly connected directly to the fluid inlet casing 2 for support thereof, without fear that the stresses produced by the rigid supply coupling will be transmitted to the compressor casing 4. Also, any vibrations, thermal expansion, settling, misalignment, etc. associated with the user's fluid supply pipes will be transmitted only to the heavy rigid base and not transmitted directly to the compressor casing. Further, this O-ring seal 38 and flexible coupling will accommodate misalignment and tolerances as between the casings 2 and 4, as well as preventing force transmittal therebetween because of the considerable radial spacing between the telescoping cylindrical portions 36, 37. Further, the inlet casing may be advantageously used for a conventional type of inlet valve, without fear that forces associated with the inlet valve will be transmitted to the compressor casing.

The compressor casing is of a one-piece cast construction with integral fluid passages between stages communicating between each stage and intercoolers within the base, respectively, so that no bulky, costly and cumbersome external piping connections are required. For this purpose, the base has a top compressor supporting wall that is provided with integral passages aligned respectively in fluid communication with the compressor casing integral passages so that fluid is conducted from the first and second stages downwardly into the intercooler chambers and upwardly from the intercooler chambers into the second and third stages.

The base is further of a compact construction in that it requires very little extra room over that of the plan view dimensions associated with the compressor casing and inlet fluid casing, with respect to its enclosure for housing intercoolers, centrifugal separators, and demisters. The intercoolers are identical and the demisters are identical to provide for interchangeability and inexpensive manufacture. Also, the separators are formed by baffles that are identical although assembled in mirror image fashion. The fluid flows downwardly through the intercoolers through a restricted passage formed by the separator baffles so that the cooled fluid approaches or reaches sonic velocity before it is sharply and reversely guided upwardly through the demisters, so that during this reversal, droplets of condensate will be discharged downwardly where they will be collected and removed if desired. The fluid moving upwardly through demisters is further directed upwardly through submanifold chambers located centrally between the two intercooler chambers for discharge through the top wall of the base. Construction of the base is rigid and relatively inexpensive in that it is of welded steel fabrication employing only planar sheets and plates, with the partition walls forming the submanifold chambers considerably contributing to the rigidity of the entire structure by providing cross bracing.

The portion of the base under the drive mechanism, particularly an electric motor and gear train, is of relatively shallow construction due to the greater height of these components and forms a sump for the oil lubrication system. Preferably this sump is in direct communication with the gear housing.

The intercoolers are mounted within their respective intercooler chambers by means of shelves so that they may be slid horizontally in one direction out of the base, after the removal of the adjacent releasably mounted wall. The wall opposite from the releasably mounted wall is provided with access means so that rigid cooling liquid supply and exhaust pipes may be quickly coupled and uncoupled from the intercoolers. In a like manner, the demisters are mounted on respective shelves to be horizontally slid out of their respective intercooler chambers in the same direction as the heat exchangers, for purposes of repair, replacement or the like.

While a preferred embodiment of the present invention has been specifically described with respect to specific advantageous features, it is to be realized that the invention, in its broader aspects, includes further modifications, embodiments and variations.