Ejectors and methods of manufacture

Abstract

An ejector has: a motive flow inlet; a secondary flow inlet; an outlet; a motive nozzle; a diffuser; and a control needle shiftable between a first position and a second position. The ejector comprises: an inlet body bearing the motive flow inlet and the secondary flow inlet; a diffuser body forming the diffuser and bearing the outlet; a motive nozzle insert forming the motive nozzle in a compartment in the inlet body; and a needle guide insert in the motive nozzle insert.

Claims

1. An ejector comprising: a motive flow inlet; a secondary flow inlet; an outlet; a motive nozzle; a diffuser; and a control needle shiftable between a first position and a second position, wherein the ejector comprises: an inlet body bearing the motive flow inlet and the secondary flow inlet; a diffuser body separately formed from the inlet body and forming the diffuser and bearing the outlet; a motive nozzle insert separately formed from the inlet body and diffuser body and forming the motive nozzle in a compartment in the inlet body; and a needle guide insert in the motive nozzle insert, the needle guide insert having a central bore for passing and guiding the needle and a plurality of off center bores for passing motive flow with a motive flow path sequentially defined: through the motive flow inlet; through the motive nozzle insert including through the off-center bores; and merging with a secondary flow flowpath.

2. The ejector of claim 1 wherein: the inlet body is a first piece; and the diffuser body is a second piece.

3. The ejector of claim 1 wherein: the inlet body is metallic; and the diffuser body is metallic.

4. The ejector of claim 1 wherein: the inlet body is threaded to the diffuser body.

5. The ejector of claim 1 wherein: the inlet body has: a first end mounting a needle actuator; and a second end mounted to the diffuser body; and the motive flow inlet is between the first end and the compartment.

6. The ejector of claim 1 wherein: the needle guide insert is brazed to the motive nozzle insert.

7. The ejector of claim 6 wherein: the motive nozzle insert is brazed to the compartment.

8. An ejector comprising: a motive flow inlet; a secondary flow inlet; an outlet; a motive nozzle; and a diffuser, wherein the ejector comprises: an inlet body bearing the motive flow inlet and the secondary flow inlet; a diffuser body forming the diffuser and bearing the outlet; a metallic motive nozzle insert being a separate piece from the inlet body and forming the motive nozzle in a compartment in the inlet body, said compartment having a downstream-facing surface abutting an upstream facing surface of the motive nozzle insert, an upstream end of the motive nozzle insert being within the compartment; a control needle shiftable between a first position and a second position; and a needle guide insert in the motive nozzle insert, the needle guide insert having a central bore for passing and guiding the needle and a plurality of off-center bores for passing motive flow with a motive flow path sequentially defined: through the motive flow inlet; through the motive nozzle insert including through the off-center bores; and merging with a secondary flow flowpath.

9. The ejector of claim 8 wherein: the needle guide insert is brazed to the motive nozzle insert.

10. The ejector of claim 8 wherein: the motive nozzle insert is brazed to the compartment.

11. The ejector of claim 8 wherein: the inlet body is a first piece; and the diffuser body is a second piece.

12. The ejector of claim 8 wherein: the inlet body is metallic; and the diffuser body is metallic.

13. The ejector of claim 8 wherein: the inlet body is threaded to the diffuser body.

14. The ejector of claim 8 wherein: the motive nozzle insert is press-fit into the compartment.

15. The ejector of claim 8 wherein: the inlet body has: a first end mounting a needle actuator; and a second end mounted to the diffuser body; and the motive flow inlet is between the first end and the compartment.

16. A method for manufacturing an ejector, the ejector comprising: a motive flow inlet; a secondary flow inlet; an outlet; a motive nozzle; a diffuser; an inlet body bearing the motive flow inlet and the secondary flow inlet; a diffuser body forming the diffuser and bearing the outlet; a motive nozzle insert forming the motive nozzle in a compartment in the inlet body; a control needle shiftable between a first position and a second position; and a needle guide insert in the motive nozzle insert, wherein a motive flow flowpath extends sequentially from the motive flow inlet, into the motive nozzle insert, through the needle guide insert, and out the motive nozzle, the method comprising: inserting the needle guide insert into the motive nozzle insert; inserting the motive nozzle insert into the compartment from an opening in a downstream end of the inlet body; and mating the diffuser body to the downstream end of the inlet body.

17. The method of claim 16 further comprising: brazing the needle guide insert to the motive nozzle insert.

18. The method of claim 16 wherein: the mating the diffuser body to the downstream end of the inlet body comprises threading.

19. The method of claim 16 further comprising: brazing the motive nozzle insert to the inlet body.

20. The method of claim 16 further comprising: mounting a needle actuator to a first end of the inlet body axially opposite the downstream end, and wherein: after the inserting of the needle guide insert and the inserting of the motive nozzle insert, the needle guide insert is axially to the downstream end side of the motive flow inlet.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic view of a prior art ejector refrigeration system.

(2) FIG. 2 is an axial sectional view of a prior art ejector.

(3) FIG. 3 is an axial sectional view of an ejector.

(4) FIG. 4 is a partial exploded axial sectional view of the ejector of FIG. 3.

(5) FIG. 5 is an end view of a needle guide of the ejector of FIG. 3.

(6) FIG. 6 is an axial sectional view of an alternate inlet body for the ejector of FIG. 3.

(7) Like reference numbers and designations in the various drawings indicate like elements.

DETAILED DESCRIPTION

(8) FIG. 3 shows an ejector 200 comprising a body assembly, 202, including a motive nozzle insert 204 within main portions of the body. General features of an ejector shared with the ejector 38 above are referenced with the same reference numerals.

(9) The exemplary body assembly 202 includes a proximal or upstream portion 210 and a distal or downstream portion 212. As is discussed further below, the exemplary portion 210 defines an inlet body bearing the motive flow inlet 40 and the secondary flow inlet 42. The exemplary portion 202 forms a diffuser body forming the diffuser and the outlet 44. As is discussed further below, the exemplary diffuser body 212 also forms at least a portion of the mixer convergent section 114 and the mixing section 116.

(10) The exemplary inlet body 210 also includes a mounting feature 220 for mounting the needle actuator 134. The exemplary mounting feature 220 is an internally threaded bore.

(11) FIG. 4 shows the inlet body 210 as having a first end 230, a second end 232, and a lateral perimeter 234 between the ends. In the exemplary implementation, the ports 40 and 42 are in the lateral perimeter 234. A compartment 240 extends inward from the second end 232 and is in communication with the ports 40 and 42. The exemplary compartment is stepped, having a relatively wide or broad downstream portion 242 at the end 232 tapering/narrowing inward/upstream with an angled shoulder 244 leading to narrow portion having sequential sections 246, 248, and 250 leading to the bore 220.

(12) As is discussed further below, the motive nozzle insert 204 is at least partially accommodated in and mounted to the compartment 240. The motive nozzle insert 204 extends from a first or upstream end 252 to a downstream end 254 providing the outlet 110. A cylindrical base or mounting portion 256 extends downstream from the end 252 and is dimensioned to be received in the compartment section 246. In the exemplary implementation, the end 252 may abut a shoulder 258 separating the compartment sections 248 and 250. The insert 204 may be secured (e.g., press-fit or brazed in place. Downstream of the mounting portion 256, the exemplary nozzle has a short straight portion 260 extending to a tapering portion 264 externally tapering to the downstream end 254 and forming the convergent and divergent portions of the motive nozzle.

(13) An interior surface of the nozzle insert 204 within the portions 256 and 260 is essentially cylindrical and accommodates a needle guide 270. The exemplary needle guide 270 (FIG. 5) is formed as an apertured disk extending between first and second ends/faces 272 and 274 (FIG. 4) and having a cylindrical perimeter 276. For passing and guiding the needle, the exemplary guide 270 has a central bore 278. For passing motive flow, the exemplary guide has a plurality of off-center bores 280. The guide 270 may be secured (e.g., press-fit or brazed) into the motive nozzle. Such press-fitting or brazing may be performed prior to installation of the motive nozzle into the inlet body. The exemplary diffuser body 212 extends from an upstream end 300 to a downstream end 302. At the upstream end, a shoulder 304 separates a boss 306 from a main lateral surface 308. The exemplary boss 306 is dimensioned to be received in the portion 242 of the compartment 240 and secured thereto. Exemplary securing is via threaded interaction of an internal thread 320 along the compartment portion 242 and an external thread 322 along the boss. To seal this threaded engagement, one or both of the shoulder 304 and downstream end 232 may bear grooves 324 for retaining O-ring seals 326 (FIG. 3). Alternative implementations involve welded, brazed, or press-fit interactions of the inlet body 210 and the diffuser body 212.

(14) FIG. 6 shows an alternate inlet body 400 wherein the actuator mounting feature 402 is an externally threaded boss contrasted with the internally threaded feature 220 of FIG. 4.

(15) In the exemplary mechanical assembly of the actuator body, the needle and actuator may be installed as a unit. Such installation may occur after mechanical assembly of the ejector to associated conduits of the vapor compression system.

(16) Exemplary materials for the inlet body 210 and outlet body 212, insert 204, and guide 270, are metals or alloys (e.g., stainless steels, brass, aluminum and its alloys, and/or titanium and its alloys).

(17) The use of first, second, and the like in the description and following claims is for differentiation within the claim only and does not necessarily indicate relative or absolute importance or temporal order. Similarly, the identification in a claim of one element as first (or the like) does not preclude such first element from identifying an element that is referred to as second (or the like) in another claim or in the description.

(18) Where a measure is given in English units followed by a parenthetical containing SI or other units, the parenthetical's units are a conversion and should not imply a degree of precision not found in the English units.

(19) One or more embodiments have been described. Nevertheless, it will be understood that various modifications may be made. For example, when applied to an existing basic system, details of such configuration or its associated use may influence details of particular implementations. Accordingly, other embodiments are within the scope of the following claims.