TITLE OF THE FNVENTION Separator Drum and Compressor Impeller Assembly

The present invention relates to fluid machinery, and more particularly to combination separator and compressor devices.

Centrifugal compressors are known and typically include one or more impellers mounted on a driven shaft and configured to pressurize gas drawn into a central inlet and to discharge the fluid radially outwardly through one or more outlets located at an outer circumferential perimeter thereof. In order to properly function, only gas should be directed into the compressor inlet, such that any liquids should be removed from a fluid stream prior to entry into the compressor. As such, compressors are often used in conjunction with a separator device to remove liquids from the fluid stream prior to entry into the compressor inlet.

One type of separator is a rotary separator that uses centrifugal force to separate out heavier liquids from the gases in a fluid stream and generally includes a rotating drum with an interior flow chamber. Such separators typically utilize static swirl vanes to increase or induce circumferential motion of the fluid stream prior to entry into the drum inner chamber, so as to increase the likelihood of the liquid coming into contact with the inner surface of the drum. However, to increase the effectiveness of the compressor operations, such prior art rotary separators are typically used in combination with a "de- swirl" device which increases the pressure of the gaseous stream and "straightens" or redirects the flow to a more axial direction. That is, the flow exiting the separator drum generally flows through a plurality of static de-swirl vanes and then into the impeller inlet. Although this manner of operating a compressor has been relatively effective, the processes of swirling and then "de-swirling" the fluid flow are believed to cause unrecovered energy losses in a gaseous stream passing through the compressor.

SUMMARY OF THE INVENTION

In one aspect, the present invention is a fluid handling assembly for a fluid machine, the machine including a casing and a shaft disposed within the casing so as to be rotatable about a central axis. The fluid handling assembly comprises an impeller mounted on the shaft and having an inlet and a rotary separator mounted on the shaft. The separator has axially spaced apart inlet and outlet ends and an interior separation chamber.

The separator is coupled with the impeller such that fluid within the separation chamber flows from the separator outlet end directly into the impeller inlet.

In another aspect, the present invention is a compressor comprising a casing, a shaft disposed within the casing and rotatable about a central axis, an impeller mounted on the shaft and having a central inlet, and a rotary separator mounted on the shaft. The separator has axially spaced apart inlet and outlet ends and an interior separation chamber. The separator is coupled with the impeller such that fluid within the separation chamber flows through the separator outlet end directly into the impeller inlet.

In a further aspect, the present invention is a fluid handling assembly for a fluid machine including a casing and a shaft disposed within the casing so as to be rotatable about a central axis. The fluid handling assembly comprises an impeller mounted on the shaft and having an inlet and an outlet, the impeller being configured to compress fluid flowing into the inlet and to discharge compressed fluid through the outlet. A rotary separator is mounted on the shaft and has axially spaced apart inlet and outlet ends and an interior separation chamber extending generally between the inlet and outlet ends. The separator is coupled with the impeller such that the separator and impeller rotate as a single unit about the shaft axis and the separation chamber is fluidly connected with the impeller inlet. Further, the separator is configured to remove at least a portion of liquid from fluid passing through the separation chamber from the inlet end and to discharge the fluid through the outlet end and directly into the impeller inlet.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The foregoing summary, as well as the detailed description of the preferred embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, which are diagrammatic, embodiments that are presently preferred. It should be understood, however, that the present invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:

Fig. 1 is a broken away, perspective view of a combination separator and compressor device having a fluid handling assembly in accordance with the present invention;

Fig. 2 is an enlarged, broken-away axial cross-sectional view of the fluid handling assembly; and

Fig. 3 is a more enlarged, broken-away axial cross-sectional view of the fluid handling assembly.

DETAILED DESCRIPTION OF THE INVENTION Certain terminology is used in the following description for convenience only and is not limiting. The words "right", left", "lower", "upper", "upward", "down" and "downward" designate directions in the drawings to which reference is made. The words "inner", "inwardly" and "outer", "outwardly" refer to directions toward and away from, respectively, a designated centerline or a geometric center of an element being described, the particular meaning being readily apparent from the context of the description. Further, as used herein, the word "connected" is intended to include direct connections between two members without any other members interposed therebetween and indirect connections between members in which one or more other members are interposed therebetween. The terminology includes the words specifically mentioned above, derivatives thereof, and words of similar import.

Referring now to the drawings in detail, wherein like numbers are used to indicate like elements throughout, there is shown in Figs. 1-3 a fluid handling assembly 10 for a fluid machine 1. The machine 1 is preferably a compressor 2 including a casing 3 and a shaft 4 disposed within the casing 3 and rotatable about a central axis 5. The fluid handling assembly 10 basically comprises an impeller 12 mounted on the shaft 4 and having a central inlet 14 and a rotary separator 16 disposed about the shaft 4. The separator 16 has axially spaced inlet and outlet ends 16a, 16b, respectively, and an interior separation chamber 18 extending generally axially between the two ends 16a, 16b. The separator 16 is coupled with the impeller 12 such that the separator 16 and impeller 12 generally rotate as a single unit about the shaft axis 5 and the separation chamber 18 is fluidly connected with the impeller inlet 14. As such, fluid flowing through the separation chamber 18 passes through the separator outlet end 16b and directly into the impeller inlet 14. Further, the separator 16 is fluidly connectable with a source SF (Fig. 1) of fluid such that fluid enters the separator inlet end 16a, the separator 16 being configured to remove at least a portion of liquid from fluid flowing through the separation chamber 18 from the inlet end 16a and to discharge the fluid through the outlet end 16 and into the impeller inlet 18.

Preferably, the impeller 12 has an end contact surface 15 located proximal to the inlet 14 and extending circumferentially about the axis 15 and the separator 16 has an end

contact surface 17 located proximal to the outlet end 16b and extending circumferential Iy about the axis 15. The separator contact surface 17 is disposed against the impeller contact surface 13 so as to define an interface Isi, the separator outlet end 16b being sealingly coupled with the impeller 12 so as to prevent fluid flow through the interface Isi. Thereby, separated or "dried" gas is prevented from flowing outwardly through the interface Isi instead of into the impeller inlet 14, but more importantly, separated liquid externally of the separator 16 is prevented from entering the impeller inlet 14 through the interface Isi-

More specifically, the impeller 12 preferably includes a shroud 20 having a generally radially-extending outer surface 21 and central opening 22, which is preferably at least partially defined by the impeller contact surface 13, the central opening 22 at least partially defining the impeller inlet 14, as described above and in further detail below. The separator outlet end 16b is either disposed against the shroud outer surface 21, so as to extend generally about the inlet opening 14, or is preferably partially disposed within the shroud central opening 22. Most preferably, the separator outlet end 16b has an inwardly stepped or offset lip 19 extending axially toward the impeller 12 and circumferentially about the axis 5. The lip 19 at least partially provides the separator contact surface 17 and is sized to fit within the inlet opening 14 of the impeller 12 such that the separator contact surface 17 is disposed within and against the impeller contact surface 13. With this arrangement, radially-outward expansion of the separator 16 during rotation thereof causes the lip 19 to seal against the inner surface 13 of the impeller 12, to thereby substantially prevent flow through the interface Isi. However, the separator 16 may be connected with the impeller 12 in any other appropriate manner (e.g., by radial flanges on the separator 16 and/or impeller 12) or may even be integrally connected or formed with the impeller 12, as discussed below.

Referring particularly to Fig. 2, the impeller 12 is preferably generally similar to a conventional centrifugal compressor impeller and includes a hub 26 mounted on the shaft 4, a plurality of vanes 28 spaced circumferentially about the axis 5, and the shroud 20 as discussed above. Each vane 28 has a first side edge 28a connected with the hub 26 and an opposing second side edge 28b, the shroud 20 being connected with the second edges 28b of all of the vanes 28 so as to be spaced axially from the hub 26 and spaced radially outwardly from the shaft 4. The central opening 22 is spaced radially outwardly from the shaft 4 so as to define the impeller inlet opening 14, which is thus preferably generally annular. Further, the hub 26 and the shroud 20 each has inner and outer edges 27a, 27b

and 3 Ia, 31b, respectively extending ciroumferentially about the central axis 5 and each vane 28 has inner and outer ends 28a, 28b, respectively. Each vane inner end 28a is located generally proximal to the inner edges 27a, 31a of the hub 26 and the shroud 20, and each vane outer end 28b is located generally proximal to the outer edges 27, 31b of the hub 26 and the shroud 20. Furthermore, each vane 28 is preferably formed so as to have a generally axial inner portion 34 extending from the first end 28a and a generally radial outer portion 35 extending from the axial portion 34 to the outer end 28b, and has opposing side surfaces 36A, 36B extending between the two ends 28a, 28b and along the inner and outer blade portions 34, 35. With this structure, the impeller 12 further has a plurality of flow channels 40, each flow channel 40 being defined between a separate one of a plurality of pairs of the vanes 28 and extending between the blade inner and outer ends 28a, 28b. Each flow channel 40 has an inlet end 33 fluid Iy coupled with the impeller inlet 14 and an outlet 32 defined generally between the hub and shroud outer circumferential edges 27b, 31b. As such, fluid entering the impeller inlet 14 flows through the inlet(s) 33 of at least one and preferably a plurality of the flow channels 40, and thereafter radially outwardly through one or more outlets 32 and generally beyond the hub and shroud outer edges 27b, 31b.

As mentioned above, the impeller 12 is at least generally similar to conventional centrifugal impellers, but preferably modified as follows. The hub 26 and the shroud 20 preferably each have an inlet end 26a, 20a, respectively, that has a greater axial length in comparison with conventional impellers, so as to extend through a static inlet member 64, as described below, and the blade inner ends 33 are also correspondingly axially lengthened. However, the impeller 12 may alternatively be constructed substantially identically to a conventional compressor impeller, with the inlet member 64 and/or separator 16 being appropriately modified to enable connection of the separator 16 with the impeller 12.

Referring to Figs. 1 and 2, the separator 16 preferably includes a generally tubular body 42 having inner and outer circumferential surfaces 44, 45, the inner surface 44 defining the separator chamber 18 and being configured to separate liquid from a mixed fluid flow F contacting the surface 44 during rotation of the separator 16. As best shown in Fig. 3, the tubular body 42 includes at least one and preferably a plurality of discharge openings 46 extending generally radially between the inner and outer surfaces 44, 45 and spaced circumferentially about the axis 5. The discharge openings 46 are configured to provide a liquid discharge or outlet passage for channeling liquids out of the separator

interior chamber 18. Further, the tubular body 42 preferably also includes a generally annular groove 48 extending radially outwardly from the inner surface 44, with the plurality of the discharge openings 46 preferably extending radially between the groove 48 and the outer surface 45. The annular groove 48 provides a collection trough for liquids on the separator inner surface 44, such liquid subsequently flowing out of the separator 16 through the discharge openings 46, as discussed in greater detail below.

Referring to Figs. 2 and 3, the separator body inner surface 44 includes a generally frustaconical section 47 having a first, radially-smaller circumferential edge 47a located at least generally proximal to the separator outlet end 16b and a second, radially-larger circumferential edge 47b spaced axially from the first edge 47a. The frustaconical surface section 47 faces generally away from the outlet end 16b so as to be configured to direct liquid L contacting the surface section 47 generally radially outwardly and away from the separator outlet end 16b during rotation of the separator 16, as indicated in Fig 3. Further, the frustaconical surface section 47 has an inside diameter that varies generally constantly along the central axis 5 from a minimum value ID _MIN at the surface section first edge 47a and a maximum value ID _MAX at the surface section second edge 47b, such that the surface section 47 tapers outwardly or generally widens in a direction Di from the outlet end 16b inwardly toward the inlet end 16a. Preferably, the second or inner edge 47b of the tubular body frustaconical surface section 47 is located at a central "transition" position or point Bc along the central axis 5 that is disposed generally between the body inlet and outlet ends 16a, 16b, with the groove 48 being located adjacent to the surface second, inner end 47b. However, the surface section 47 may alternatively extend substantially entirely through the body 42, such that the surface section second end 47b is located at the separator inlet end 16a. Furthermore, the body inner surface 44 preferably further has a generally cylindrical, constant diameter section 49 extending between the central position Bc and the inlet end 16a, the cylindrical surface section 49 having an inside diameter IDs that is at least generally constant (i.e., equal to the maximum value IDMA _X ), as indicated in Fig. 3. Thus, the body inner surface 44 preferably formed having both the frustaconical, tapering diameter section 47 and the cylindrical, constant diameter section 49. With this surface structure, liquid contacting the tapering section 47 of the inner surface 44 during rotation of the separator 16 is directed or "forced" to flow generally toward the body central position Bc, and then flows into the groove 48 and out of the separator 16, as described above.

Referring again to Figs. 1-3, the separator 16 also preferably includes a generally tubular inner deflector member 50 mounted on the shaft 4 and disposed within the separation chamber 18. The deflector member 50 has a radially outwardly curved outer circumferential surface 53 spaced radially inwardly from the tubular body inner surface 44, such that a generally annular flow channel 49 through the rotary separator 16 is defined between the facing surfaces 44, 53. The deflector member 50 is configured to direct liquids contacting the curved outer surface 53 generally toward the separator body inner surface 44 (as indicated in Fig. 3) for subsequent removal from the separator 16 as described above. More specifically, the deflector member 50 includes a generally tubular body 51 having opposing ends 51a, 5 Ib and a through bore 55 extending between the ends 51a, 51b, the bore 55 being sized to receive a portion of the shaft 4. Further, the deflector tubular body 51 has an enlarged central portion 51c, such that the body outer surface 53 has an outside diameter that varies between about a minimum value OD _MIN proximal to each body end 51 , 5 Ib to a maximum value OD _MA X within the body central portion 51c. As such, liquids contacting the deflector body 50 at directed generally radially outwardly toward the separator body inner surface 44 by the curve shape of the deflector outer surface 53.

Referring again to Figs. 1 -3, the separator 16 preferably includes a plurality of generally radially extending flow blades 52 disposed proximal to the inlet end 16a and spaced circumferentially about the axis 5. The blades 52 also extend generally parallel with the shaft axis 5 and are configured to accelerate fluid flowing into the separator inlet end 16a. More specifically, energy of the rotating shaft 4 is transferred to fluid flowing into the inlet end 16a when the fluid contacts the rotating flow blades 52, such that the blades 52 transmit momentum to the fluid. This transferred energy/momentum causes the fluid to accelerate to the speed of the rotating shaft 4, which increases the efficiency of the compression process when the separated fluid flows into the impeller 12. As such, the downstream inducer portion of a conventional impeller inlet may be eliminated.

Preferably, the separator body 42 includes an inlet member 54 providing the inlet end 16a and the preferred flow blades 52 and a generally tubular drum member 56 connected with the inlet member 54 and the impeller 12 and providing the outlet end 16b. The inlet member 54 includes an annular hub 58 mounted on the shaft 4 and a generally annular outer wall 60 spaced radially outwardly from the hub 58, the plurality of blades 52 extending radially between the hub 58 and the annular wall 60. Further, the tubular drum member 56 has a first end 56a connected with the inlet member 54, a second end 56b

spaced axially from the first end 56a (which provides the separator outlet end 16b) and an connected with the impeller 12, and an inner surface providing surface a substantial portion of the separator inner surface 44, as described above. The drum member 56 includes the inwardly offset circumferential lip 19 at the second end 56b and preferably also includes a generally axially extending circumferential tongue 57 engageable with a mating, overlapping tongue 59 of the inlet member 54. As such, the drum 56 is preferably "sandwiched" between the inlet member 54 and the impeller shroud 20 so as to be axially retained thereby. Further, the inner deflector member 50 is preferably sandwiched between the inlet member hub 58 and the impeller hub 26, and thus axially retained. Although the two-piece structure 54, 56 as described above is presently preferred, the separator 16 may alternatively be formed of a single generally tubular body or of three of more connected together members/pieces (neither shown). Further, as mentioned above, the rotary separator 16 may alternatively be integrally formed with the impeller 12 as opposed to being fixedly or removably connected. The scope of the present invention includes these and all other appropriate constructions of the separator 16 and/or the impeller 12 which function generally as described herein.

Referring to Figs. 1 and 2, the fluid machine 1 or compressor 2 also preferably includes a static compressor inlet member 64 having a central opening 65 configured to receive at least a portion of the impeller 12 with clearance, so as to preferably avoid contact between the inlet member 64 and the impeller 12. The static member 64 is configured to partially bound the compressor first or inlet stage, and is fixedly supported by the casing 3. Further, the static member 64 preferably includes a generally disk-like circular body 66 with a generally axially-extending, circular ridge 67 extending about the central opening 65, which generally overlaps the interface ϊsi of the separator 16 and the impeller 12, and a generally circular groove 68 (Fig. 1) spaced radially outwardly from the ridge 67 and extending circumferentially about the axis 5. The static member groove 68 is configured to receive an end portion of a static separator member 70, as discussed below.

Referring particularly to Fig. 1 , the preferred compressor 2 is preferably a "multistage" compressor that further includes at least one and preferably two or more other impellers (none shown) spaced axially from the "first stage" impeller 12, such that the first stage impeller 12 is disposed generally axially between the separator 16 and the other or "latter stage" impeller(s). The plurality of outlets 32 of the first stage impeller 12 are fluidly coupled with an inlet (not shown) of an adjacent impeller, and each latter stage impeller is at least generally similarly constructed as the inlet impeller 12. However, the

combination separator compressor device 2 may alternatively include only the single impeller 12.

Preferably, the compressor 2 further comprises a static separator 70 disposed about the rotary separator 16 and having an inner circumferential separation surface 71 spaced radially outwardly from the separator so as to define a generally annular flow passage 72 fluidly coupled with the rotary separator inlet end 16a. The static separator 70 is preferably constructed such that fluid F flows through the annular flow passage 72 in a first axial direction Di, with the static member separation surface 71 being configured to remove liquid from fluid contacting the surface 71. Further, a generally annular casing inlet passage 74 is fluidly connected with the separator passage 72, preferably through a radial port 76. A plurality of fluid vanes 78 are preferably disposed within the radial port 76 and are configured to initiate swirling motion within the separator passage 72, such that the liquid flow is directed generally onto an inner surface 71 of the static separator 70. Furthermore, the static separator 70 also preferably includes a generally radially-extending wall 80 spaced axially from the separator inlet end 16a, the radial wall 80 being configured to direct fluid F exiting the annular flow passage 72 to flow generally in a second, opposing direction D2 into the separator inlet end 16a.

With the above structure, a fluid stream F first flows generally radially through the vanes 78 and is deflected to flow generally axially about in the first direction Di within the annular inlet passage 74, such that at least larger fluid particles are preferably separated by contact with the static separator inner surface 71. Next, the fluid is directed to flow radially about the rotatable separator inlet end 16a and then axially in the opposing direction D2 into the flow blades 52, such that the fluid stream is accelerated by contact with the blades 52. Portions of flow proximal to the shaft 4 contact the rotatable deflector 50 and are directed toward the separator inner surface 44, whereas other stream portions flow directly into contact with the separator surface 44. Due to such contact with the rotating, angled surface 44, liquid in the fluid stream F first adheres to the surface 44, flows generally in the first axial direction Di to the collection groove 48, and thereafter out of the separator 16 through the discharge openings 46. The substantially gaseous portions of the fluid stream F then flows out of the separator chamber 18 and directly into the impeller inlet 14. Any remaining small liquid droplets or mist in the gas flow stream are centrifuged out to the separator surface 44 by the swirling motion of the gas relative to the central rotational axis 5.

The fluid handling assembly 10 of the present invention provides a number of benefits over previously known separator-compressor assemblies/devices. By eliminating the static swirl and de-swirl vanes at the separator inlet and outlet, respectively, the assembly 10 reduces the total axial space (i.e., along the shaft 4) required for the various components of the combination separator and compressor device 2. Also, by connecting the rotary separator 16 with the impeller 12, such that both components 12, 16 rotate generally as a single unit, the need to seal the outlet end 16b of the rotary separator 16 against a static component of the fluid machine 1 is eliminated. Thereby, a potential flow path for the reintroduction of liquid into the separated gas stream F is also eliminated. Further, as discussed above, due to the fact that the fluid stream F flowing through the separator 16 is not swirled at the separator inlet 16a and then de-swirled prior to entry into the impeller 12, energy losses are reduced and compressor efficiency is increased.

It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as generally defined in the appended claims.