US3778983A

US3778983A - Integral multichannel separator

Info

Publication number: US3778983A
Application number: US00284771A
Authority: US
Inventors: G Rygg
Original assignee: Avco Corp
Current assignee: Avco Corp
Priority date: 1972-08-30
Filing date: 1972-08-30
Publication date: 1973-12-18
Anticipated expiration: 1990-12-18

Abstract

An integral multichannel separator for separating and removing foreign particles from engine inlet air is disclosed. The multichannel separator utilizes a plurality of concentric rings mounted in the air inlet passageway to divide the passageway into multiple flow paths. Each ring has a particle entrapping portion at the trailing edge. Each particle entrapping portion of the rings is connected with scavenge struts which support the rings as well as transport the particles for disposal. Deflector rings cooperate to prevent particle rebound into the main airstream.

Description

Unite States atent ll I'll" I /f I I IF- Rygg 1 Dec. 18, 1973 INTEGRAL MULTHCHANNEL SEPARATOR 3,673,77l 7/1972 Dickey 55/306 [75] Inventor: Gregers G. Rygg, Oxford, Conn. Primary Examiner Bemard Nozick [73] Assignee: Avco Corporation, Stratford, Conn. AttorneyCharles M. Hogan et al.

22 Pl d: A 30, 1972 l 1 57 ABSTRACT [21] Appl 234;! An integral multichannel separator for separating and removing foreign particles from engine inlet air is dis- [52] US. Cl. 55/306, 55/440, 60/39.()9 P, closed. The multichannel separator utilizes a plurality 244/53 B 417/12] of concentric rings mounted in the air inlet passage- [511 im. c1 Bold 45/08 y to divide the passageway into multiple flow p [58] Field of Search 55/306, 307, 440; E g has a p i mr pping portion at the trail- 60/39 09 P; 244/53 B; 417/121 G ing edge. Each particle entrapping portion of the rings is connected with scavenge struts which support the [56] Referenc Cit d rings as well as transport the particles for disposal. De-

UNITED STATES PATENTS flector rings cooperate to prevent particle rebound 2,931,460 4/1960 McEachern 55/306 mm the a'rstream 3,148,043 9/1964 Richardson et al 55/306 7 Claims, 3 Drawing Figures INTEGRAL MULTICI-IANNEL SEPARATOR BACKGROUND OF THE INVENTION This invention relates to air intakes, particularly intakes for gas turbine engines which are required to operate in sand or dust laden air, and more particularly to an integral multichannel separator incorporated in the air intake passageway.

The use of turbine-powered helicopters in severe sand laden atmospheric conditions has resulted in a dramatic increase in cases of engine erosion damage and has underscored the need for effective systems to protect gas turbine engines from sand and dust ingestion. Solutions to these problems have yielded a wide variety of particle separator concepts which are generally appended to the engine installation. Examples of such separators are shown in U. S. Pat. Nos. 3,371,471 and 3,534,548, both issued to H. D. Connors, and U. S. Pat. No. 3,521,431 issued to H. D. Connors and F. D. Buckley, all of which are assigned to Avco Corporation.

The increased engine protection afforded by these units has more than justified their use. However, physical limitations imposed by this add-on approach sometimes result in the aircraft system suffering from lower sand collection efficiencies, higher weight, and larger losses in power than may be necessary. These problems can be significantly reduced by providing a particle separator which is incorporated within the engine air inlet. An example of such a separator is U. S. Pat. No. 3,673,71 l issued to T. A. Dickey and assigned to Avco Corporation. Use of swirl and deswirl vanes such as in the Dickey patent, in some instances, may not be desirable.

Accordingly, it is an object of this invention to provide an improved particle separator which is integral with the engine air inlet passageway and which does not impart swirl and deswirl to the airflow in the particle separator stage.

A further object of this invention is to provide a particle separator having high scavenge efficiency due to inertia separation.

A still further object of this invention is to provide a particle separator having multichannel separating facilities and which further operates as an FOD screen.

Another object of this invention is to provide a particle separator which exploits inlet housing curvature to provide effective particle separation.

Yet another object of this invention is to provide a particle separator which lends itself to installation within existing engine intake passageway structures.

SUMMARY OF THE INVENTION This invention provides an improved integral multichannel separator for removing foreign particles from the stream of air supplied to the compressor of an engine. The separator consists of static components which are mounted in the annular air intake passageway. A plurality of concentric rings is mounted in the passageway by hollow scavenge struts. The trailing edge of each ring includes a particle catching portion displaced axially one to the other to minimize pressure loss due to the drag of the catching portion. The catching portion of each ring is supported by and is in communication with the hollow struts. A sawtooth shape of the catching portion allows captured particles to flow therealong into the hollow struts. Concentric deflector rings are associated with each concentric ring to prevent particle rebound into the main airstream.

Other details, uses, and advantages of this invention will become apparent as the following description of the exemplary embodiment thereof presented in the accompanying drawings proceeds.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings show a present exemplary embodiment of this invention in which:

FIG. 1 is a side view, partially cut away, through part of the air intake of a gas turbine engine which is provided with the multichannel particle separator according to the present invention;

FIG. 2 is a sectional view (not to scale) taken along line 22 of FIG. 1 downstream of the separator and looking upstream; and

FIG. 3 is a sectional view taken along line 33 of FIG. 2 particularly showing the sawtooth shape of the catching lips.

DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT Reference is now made to FIG. 1 which illustrates one exemplary embodiment of the improved particle separator of this invention which is designated generally by the reference numeral 110. The separator 10 is mounted at the forward end of the turbine engine just ahead of the compressor stage 12. The annular gear housing 14 forms the inner wall of the engine air inlet passageway 16. The outer wall of the passageway 16 is defined by the annular inlet housing 18.

The particle separator 10 is mounted downstream of the entrance of the air inlet passageway 16 and before the first compressor stage 12 defined by the axial compressor casing 20. The separator 10 comprises a plurality of annular concentric cylinders or

rings

22, 24 and 26 mounted in the air passageway 16. The

rings

22, 24 and 26 provide splitter walls to define a plurality of smaller annular passageways in passageway 16. The concentric ring 26 forms the inner wall of a manifold chamber 28 for which wall 30 defines the outer dimension of the manifold 28.

Each

concentric ring

22, 24 and 26 is supported and secured, by any suitable means, in the passageway 16 by hollow struts 311. The struts 31 are mounted in radial fashion about the passageway 16. The outer end of each strut 31 is connected to and in communication with the manifold chamber 28. Each

concentric ring

22, 24 and 26 is formed with a particle catching portion or

lip

32, 34 and 36, respectively, at the respective trailing edge thereof. The

catching lips

32 and 34 are in open communication with the adjacent hollow struts 31. It should be noted that the catching lip 36 is a flange member separated from the concentric ring 26 but may be considered as a cooperating element of the concentric ring 26. The area defined by the catching lip 36 and the concentric ring 26 is in direct communication with the manifold chamber 28. Accordingly, it is seen that any particles which are captured by the

catching lips

32, 34 and 36 will be transmitted to the manifold chamber 28 either through the hollow strut 31 in the case of

lips

32 and 34 or directly to the chamber 28 in the case of lip 36.

In order to enhance the transmission of entrapped particles from the catching lips to the hollow strut 31 or chamber 28, the

catching lips

32, 34 and 36 are formed in a chevron or sawtooth pattern between supporting struts, as seen in FIG. 3. For illustrative purposes in FIG. 3, concentric ring 22 and catching lip 32 has been unfolded in a linear fashion. In the drawings, clean air is represented by long arrows and the dust or foreign particles are diagrammatically represented by dots and dashes. The sawtooth pattern of the catching lips between the supporting struts allows the captured particles to flow along respective catching lip and into the scavenge strut. It is further seen that of all the particles trapped between two supporting struts, one half of the particles will flow to one strut and the remainder will flow to the other strut. Any suitable means such as a blower or the like (not shown) may be used to transmit the particles from the hollow struts 31 to the manifold chamber 28 from whence they are exhausted overboard through suitable means such as ejector tubes or the like 38 which are mounted on wall 30 in open communication with chamber 28.

in order to minimize the particle rebound effects, i.e., particles striking the concentric ring and rebounding into the main airstream, concentric deflector cylinders or rings 42, 44 and 46 are mounted in the passageway 16 in close proximation to the respective concentric ring. The deflector rings 42, 44 and 46 are supported in passageway 16 by the struts 31. The deflector rings are positioned radially inward from each respective concentric ring in such a way that particles rebounding from the respective concentric rings will engage the respective deflector ring thereby being prevented from returning to the main stream, such particles, because of their inertia, will be carried into the catching lip portion. Aslight air gap exists between the downstream end of each deflector ring and the upstream edge of each catching lip such that a portion of the air passing between respective concentric ring and deflector ring will be able to return to the main airstream.

Referring once again to FIG. I, it is seen that the catching

lip portions

32, 34 and 36 of each respective

concentric ring

22, 24 and 26 are displaced axially downstream one to the other to minimize blockage effects and pressure loss to drag on the catching lips.

in operation, the particle laden air enters the passageway l6 and travels in an axial direction. The particles are carried by their inertia to the catching lip portion as the airstream is accelerated through the curvature of the passageway 16. A portion of the air passing between the concentric ring and deflector ring will be able to return to the main airstream through the slots just upstream of the upstream edge of the catching lips while the sand, because of its inertia, will be carried into the catching lip. It may be further seen that the separator will serve as an FOD screen for preventing ingestion of large objects through the passageway to the compressor stage 12.

Because of the unique structural features of the particle separator of this invention, it is seen that there is no need for extraneous add-on structures to be placed on the engine. The particle separator is mounted in the air inlet passageway upstream of the first compressor stage. Accordingly, it can be seen that this invention accomplishes the objectives hereinabove set forth.

While a present exemplary embodiment of this invention has been illustrated and described, it will be recognized that this invention may be otherwise variously embodied and practiced by those skilled in the art.

What is claimed is:

1. In a gas turbine engine the combination comprising:

an air intake passageway;

a plurality of concentric separating elements mounted in said passageway and dividing said passageway into plural flow paths, said elements having a particle entrapping portion at the trailing edge thereof;

a plurality of concentric deflector rings of like number as said separating elements mounted in said passageway, a deflector ring being mounted in close proximation to a separating element and positioned radially inward therefrom wherein particles rebounding from said separating elements will be prevented from returning to the passageway whereby such particles will be carried into the particle entrapping portion due to particle inertia; and

a row of spaced radially extending hollow struts mounted in said passageway, said row of struts supporting said concentric separating elements and said deflector rings, said struts having openings therealong wherein said hollow interior of each strut is in communication with the particle entrapping portion for receiving particles entrapped thereby.

2. The combination according to claim 1 in which the outermost concentric separating element defines the inner wall of a manifold chamber;

an outer wall cooperating with said outermost separating element to define the manifold chamber, said manifold chamber being in communication with said hollow struts for receiving particles therefrom.

3. The combination according to claim 2 in which said particle entrapping portion of the outermost separating element is separated therefrom wherein direct communication is provided between said outermost separating element and said manifoldchamber.

4. The combination as set forth in claim 1 in which said concentric separating elements comprise concentric rings and in which the entrapping portion of each separating ring is a catching lip.

5. The combination as set forth in claim 4 in which the downstream edge of each deflector ring terminates upstream of the leading edge of the respective catching lip wherein a slight air gap exists therebetween whereby air passing between the respective concentric ring and deflector will be able to return to the passageway.

6. The combination according to claim 4 in which said catching lip extending between any pair of hollow struts is formed in a sawtooth shape whereby particles entrapped thereby will flow therealong to one or the other of said hollow struts.

7. A multichannel separator in an inlet of a gas turbine engine comprising:

a plurality of concentric rings mounted in the inlet passageway, each of said rings terminating, said rings defining a plurality of passageways within the inlet passageway;

a catching lip at the downstream end of each concentric ring and cooperating therewith to catch particles within the passageway;

a concentric deflector ring mounted in said inlet passageway in close proximity with each concentric ring, each deflector ring being positioned radially inward from -each respectively concentric ring;

lips wherein said catching lips are in communication with the interior of said hollow struts whereby particles entrapped by each catching lip are transmitted to the interior of said hollow strut.

Claims

1. In a gas turbine engine the combination comprising: an air intake passageway; a plurality of concentric separating elements mounted in said passageway and dividing said passageway into plural flow paths, said elements having a particle entrapping portion at the trailing edge thereof; a plurality of concentric deflector rings of like number as said separating elements mounted in said passageway, a deflector ring being mounted in close proximation to a separating element and positioned radially inward therefrom wherein particles rebounding from said separating elements will be prevented from returning to the passageway whereby such particles will be carried into the particle entrapping portion due to particle inertia; and a row of spaced radially extending hollow struts mounted in said passageway, said Row of struts supporting said concentric separating elements and said deflector rings, said struts having openings therealong wherein said hollow interior of each strut is in communication with the particle entrapping portion for receiving particles entrapped thereby.

2. The combination according to claim 1 in which the outermost concentric separating element defines the inner wall of a manifold chamber; an outer wall cooperating with said outermost separating element to define the manifold chamber, said manifold chamber being in communication with said hollow struts for receiving particles therefrom.

3. The combination according to claim 2 in which said particle entrapping portion of the outermost separating element is separated therefrom wherein direct communication is provided between said outermost separating element and said manifold chamber.

7. A multichannel separator in an inlet of a gas turbine engine comprising: a plurality of concentric rings mounted in the inlet passageway, each of said rings terminating, said rings defining a plurality of passageways within the inlet passageway; a catching lip at the downstream end of each concentric ring and cooperating therewith to catch particles within the passageway; a concentric deflector ring mounted in said inlet passageway in close proximity with each concentric ring, each deflector ring being positioned radially inward from each respectively concentric ring; a plurality of radially extending hollow struts mounted in said inlet passageway, said struts supporting each concentric ring and catching lip and deflector ring, said strut having openings therealong in communication with each of said catching lips wherein said catching lips are in communication with the interior of said hollow struts whereby particles entrapped by each catching lip are transmitted to the interior of said hollow strut.