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Title:
STEAM/AIR EJECTOR FOR GENERATING A VACUUM
Document Type and Number:
WIPO Patent Application WO/1990/004720
Kind Code:
A1
Abstract:
An ejector (10) is provided, which has an easily replaceable nozzle unit (22). The ejector includes a steam chest (16), a suction chamber (18), a diffuser (20) and a nozzle unit, wherein the steam chest has an outside end wall (24) having an opening with a removable cap (32) for removing the nozzle unit and for replacing the nozzle unit, or a duplicate thereof, through the opening. The steam chest has an axis and has a coaxial steam chest cavity (29) with an inlet opening (34) for steam. The suction chamber connects coaxially to the steam chest and has a coaxial suction chamber cavity with an inlet opening. The diffuser is coaxial with the steam chest and the suction chamber and has an elongate coaxial passage for exhausting the suction chamber cavity. The nozzle unit interconnects the steam chest cavity and the suction chamber cavity and is coaxial therewith.

Inventors:
ERIKSEN OLOF A (US)
Application Number:
PCT/US1989/004479
Publication Date:
May 03, 1990
Filing Date:
October 13, 1989
Export Citation:
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Assignee:
UNIQUE SYSTEMS INC (US)
International Classes:
F04F5/20; (IPC1-7): F04F5/00
Foreign References:
FR769929A1934-09-04
US1509090A1924-09-23
US2310265A1943-02-09
FR933502A1948-04-23
DE15681C
US2631774A1953-03-17
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Claims:
1. An ejector comprising: a steam chest having an axis and having a coaxial steam chest cavity with an inlet opening; a suction chamber connecting coaxially to the steam chest and having a coaxial suction chamber cavity wit an inlet opening; a diffused coaxial with the steam chest and the suction chamber and having an elongate coaxial passage for exhausting the suction chamber cavity; a nozzle unit extending through the steam chest cavity and the suction chamber cavity coaxially therewith; said steam chest having an outside end wall and a peripheral wall and in inside end wall enclosing the steam chest cavity; said outside end wall having an opening disposed coaxially with the nozzle unit; and said opening having a removable cap for removing th nozzle unit and for replacing the nozzle unit or a duplicat thereof through the opening, wherein the nozzle unit has a enlarged portion having a bearing surface for engaging a bearin surface in the steam chest, and wherein the nozzle unit has a externally threaded portion for receival in an internally threade hole in the steam chest, and wherein the nozzle unit has a elongate passage interconnecting the steam chest cavity with th suction chest cavity with suction chamber cavity.
2. The ejector of claims 1, wherein the nozzle unit has a end portion with an opening, and wherein the nozzle unit has nozzle insert received in the end portion opening, said nozzl insert having a passage portion, said passage portion having a inlet portion and a necked down portion and an outlet portion, an wherein said steam chest inside wall and an adjacent end wall o the suction chamber have plurality of matching holes of the sam angular spacing and overall diameter for a plurality of bolts an wherein said diffused and said section chamber have bare adjacen respective wall portions having plurality of matching holes of the same angular spacing and overall diameter for a plurality of oolts for facilitating joining of said steam chest inlet opening and suction chamber inlet opening to outside piping connections.
3. The ejector of claim 1, wherein the steam chest inside end wall is a onepiece plate having an axially inner surface, and wherein the steam chest peripheral wall has an axially outer surface, said axially inner surface and said axially outer surface being joined by an annular butt weld.
4. The ejector of claim 1, wherein the steam chest inside end wall has an annular projecting portion, said annular projecting portion having a radially outer, externally threaded surface for receival in a threaded hole of an ejector suction chamber.
5. The ejector of claim 1, wherein the nozzle unit has an elongate passage interconnecting the steam chest cavity with the suction chamber cavity.
6. The ejector of claim 5, wherein the nozzle unit has an end portion with an opening, and wherein the nozzle unit has a nozzle insert received in the end portion opening, said nozzle unit has a nozzle insert received in the end portion opening, said nozzle insert having a passage portion, said passage portion having an inlet portion and a necked down portion and an outlet portion.
7. The ejector of claim 6, including a lock nut for locking in place said nozzle unit, said lock nut having a passage portion for interconnecting the suction chamber cavity with the nozzle unit passage.
Description:
Steam/Air Ejector For Generating A Vacuum

The invention generally relates to an ejector, and i particular the invention relates to a steam chest allowin for an easily replaceable nozzle subassembly.

Background of the Invention The prior art ejectors include a steam chest having an axis and a steam chest cavity, a suction chamber coaxial with the steam chest and having a suction chamber cavity, a diffuser coaxial with steam chest and suction chamber and having an elongate passage, a nozzle subassembly extending from the steam chest through the suction chamber cavity, and a construction joint disposed between the steam chest and suction chamber for disassembly and reassembly thereof for replacing, cleaning or repairing the nozzle subassembly. One problem with the prior art ejector assembly is that the time to disassemble and reassemble the steam chest and the nozzle subassembly into the suction chamber is relatively long causing extensive down time of the associated processing equipment.

Summary of the Invention According to the present invention, a modified ejector is provided which is easily disassembled. This ejector includes a steam chest having an axis and having a steam chest cavity, a suction chamber coaxial with the steam chest and having a suction chamber cavity, a diffuser coaxial with the steam chest and the suction chamber and having an elongate passage, a nozzle subassembly extending through the steam chest cavity and the suction chamber cavity, said steam chest having an outside end wall and a peripheral wall and an inside end wall

with the nozzle subassembly, said opening having a removable cap for removing and replacing the nozzle subassembly therethrough. By using the end wall opening and removable cap disposed coaxially with the nozzle subassembly, the time of replacing the nozzle subassembly is minimized. The foregoing and other objects, features and advantages will be apparent from the following description of preferred embodiments of the invention as illustrated in the accompanying drawings.

Brief Description of the Drawings Figure 1 is a section view of an ejector assembly according to the invention; Figure 2 is a section view of a second embodiment of the ejector with a steam chest portion; and Figure 3 is a section view as taken along the line 3-3 of Figure 2. Figures 4 is a section view of a third embodiment of the steam chest portion of the ejector; and Figure 5 is a section view of a fourth embodiment of the steam chest portion of the ejector.

Description of the Preferred Embodiments As shown in Figure 1, a steam ejector 10 is provided. The ejector 10 has an elongate axis 12 and is a welded subassembly having a typical weld 14. The ejector 10 includes a steam chest 16, which has a round profile in cross section, and includes a suction chamber 18, which has a cylindrical profile in cross section. The ejector 10 also includes a diffuser 20, which has a cylindrical profile in cross section, and includes a nozzle subassembly 22, which also has a cylindrical profile in cross section and which is disposed inside the steam chest 16 and suction chamber 18, and which is supported by the steam chest 16.

The steam chest 16 has a left outside end wall 24, peripheral wall 26 and a right inside end wall 28 forming cavity 29. The left end wall 24 has an internally threade hole 30 with an externally threaded cap or plug 32. The peripheral wall 26 has a threaded pipe connection 3 for use as a fluid inlet or an air inlet or a steam inlet Right end wall 28 has a plurality of connector holes 36 fo bolts (not shown) for forming an assembly joint 37. The righ end wall 28 has an inner wall portion 38, which has a internally threaded hole 40, that is coaxial with nozzl subassembly 22. The suction chamber 18 has a left end wall 42, peripheral wall 44, and a right end wall 46 forming a cavit 47. Walls 42, 44, 46 have a cylindrical profile in cros section. The left end wall 42 has an inner hole 48, which i coaxial with hole 40, and with nozzle subassembly 22. Lef end wall 42 has a plurality of connector holes 50 which ar aligned with respective holes 36. The peripheral wall 44 has a pipe portion 52, which ha an internally threaded hole 54 for a conventional vacuum gag (not shown) . Peripheral wall 44 has a flange connection 56 which has an inlet opening 58 for connection to a conventiona condenser (not shown) . Right end wall 46 has an inner hole 60, which has a inner diameter that decreases in size from left to right Hole 60 is coaxial with hole 48. The right end wall 46 als has a plurality of connector holes 62 for bolts (not shown) . The right end wall 28 of the steam chest 16 also has bearing surface or machined surface 64 on its axially inne side. Surface 64 is a stop surface for threading nozzl assembly 22 into place, as explained hereafter, afte inserting nozzle assembly 22 through hole 30. Diffuser 20 has a left end wall 66, a peripheral wal 68, and a right end wall 70. The left end wall 66 ha

respectively aligned with holes 62. Peripheral wall 68 is connected to right end wall 70 which has a plurality o connector holes 82. Diffuser 20 has an elongate passage 84, which has a selective elongate inner profile, and which has an inlet portion 86 and a necked down portion 88 and discharge portion 90. The nozzle subassembly 22 has a left end portion 92 o hexagonal profile in cross section, and an enlarged portio 94, which has a bearing surface 96 that engages bearin surface 64. The nozzle subassembly 22 has a threaded portio 98, which is threaded into threaded hole 40, and has a righ end portion 100. The nozzle subassembly 22 further has a elongate passage 102. Right end portion 100 has an internally threaded portion 104, which receives a nozzle insert 106. The insert 106 has a externally threaded portion 108, which is received in portio 104. The insert 106 has a passage 110, which has an inle portion 112, a necked down portion 114 and an outlet portio 116. With the construction of the ejector 10, end cap 32 ca be removed in order to remove nozzle subassembly 22 throug end hole 30. Thus, the time to replace nozzle subassembly 22 is minimized. The primary benefit of ejector 10 is that it ca be easily taken apart to replace the nozzle assembly 22, whic is the part that has the most wear. Following are advantages of the ejector 10: Only the step of checking or removing nozzle assembly 22 is required. Many additional steps to check the prior ar ejector are avoided. First, disconnect of steam line is avoided. Second, removal of steam pressure gage is avoided. Third, removal of steam chest bolts is avoided. Fourth, prying loose of steam chest is avoided. Fifth, unscrewing extensions and removing spacers ar avoided.

* 1 Sixth, after checking the nozzle subassembly, the

2 reinstalling of a gasket between the steam chest and suction

' - 3 chamber is avoided.

4 Seventh, reinstalling the steam chest bolts is avoided.

5 Eighth, reinstalling the steam pressure gage is avoided.

6 Ninth, reconnecting the steam line is avoided.

7 Other advantages of generator 10 are indicated below:

8 Only the detail steps of unscrewing the cap 32 and nozzle

9 subassembly 22 using wrenches, and later screwing back the

10 nozzle subassembly 22 and cap 32 are required.

11 Figure 2 shows a second embodiment or ejector 10a. Parts

12 of ejector 10a in Figure 2, which are the same as parts of the

13 ejector 10 in Figure 1, have the same numerals, but with a

14 subscript "a" added thereto. Figure 2 corresponds to a

15 portion only of Figure 1.

16 The ejector 10a which has an axis 12a, includes a steam

17 chest 16a and a nozzle subassembly 22, supported therefrom.

18 The steam chest 16a has a left wall 24a, a peripheral wall

19 26a and a right wall 28a. Left wall 24a has an internally

20 threaded end hole 30a. The peripheral wall 26a has an

21 internally threaded gage hole 144 and has an internally

22 threaded pipe connection 34a. Right wall 28a has a plurality

23 of connector holes 36a and an inner wall portion 38a, which

24 has a threaded inner hole 40a.

25 Nozzle subassembly 22a has an enlarged portion 118 with

26 a bearing surface 120 which engages a surface 64a on wall 38a.

27 Nozzle subassembly 22a has an externally threaded portion 122

28 and a right end portion 124. The nozzle subassembly 22a also

29 has a passage 126. The passage 126 has an inlet portion 128,

30 a necked down portion 130, and an outlet portion 132.

^ 31 The nozzle assembly 22a has a lock nut 134. Peripheral

32 wall 26a has an internally threaded portion 136; and lock nut

33 134 has an externally threaded portion 142, received by

34 portion 136. The lock nut 134 has a passage portion 138 which

35 is coaxial with passage 126. Lock nut 134 also has- two tool

receiving holes 140, which can receive a tool wrench with a dual prong head (not shown) . The nozzle assembly 22a is better able to resis loosening thereof due to vibration, because lock nut 134 provides a locking force thereon. The nozzle assembly 22a is less complicated to manufacture, as it is one piece; and it is more rigid, as it has a smaller length to diameter ratio. Figure 4 shows a third embodiment of a steam chest 16b, which has a circular profile in cross section and which is portion of an ejector. Parts of steam chest 16b in Figure 4, which are the same as parts of steam chest 16 in Figure 1, have the same numerals, but with a subscript "b" adde thereto. Figure 4 corresponds to a steam chest portion onl of Figure 1. Steam chest 16b, which has an axis 12b, includes a lef outside end wall 25b, a peripheral wall 26b and a right insid end wall 28b. Left wall 24b has an internally threaded en hole 30b. Peripheral wall 26b has an internally threaded gag hole 150, and has an internally threaded pipe connection 34b. Right wall 28b has a plurality of connector holes 36b, and ha an inner wall portion 38b, which has a threaded inner hol 40b, inner wall portion 38b has an axially inner bearin surface 64b for bearing against a nozzle assembly. Right wall 28b has an axially inner machined surfac portion 152. Peripheral wall 26b has an axially oute machined surface 154, which faces surface 152. • Surfaces 15 and 154 have an annular butt weld 156, which is dispose therebetween. Right wall 28b has an axially outer surfac 158 for forming part of a construction joint with a left wal of an ejector suction chamber. Right wall 28b is a circular, one piece, machined plat for ease of manufacture thereof. Figure 5 shows a fourth embodiment of a steam chest 16 which has a circular profile in cross section. Parts of stea chest 16c, which are the same as parts of steam chest 16 i

Figure 1, have the same numerals, but with a subscript "c" added thereto. Figure 5 corresponds to a steam chest portion only of Figure 1. Steam chest 16c, which has an axis 12c, includes a left outside end wall 24c, a peripheral wall 26c, and a right inside end wall 28c. Left wall 24c has an internally threaded end hole 30c. Peripheral wall 26c has an internally threaded gage hole 170, and has an internally threaded pipe connection 34c. Right wall 28c has an inner wall portion 38c, which has a threaded inner hole 40c. Inner wall portion 38c has an axially inner bearing surface 64σ for bearing against a nozzle assembly. Right wall 28c has an axially outer surface 172 for forming part of a construction joint with a left wall of an ejector suction chamber. Right wall 28c has a projecting portion 174 which has a radially outer, externally threaded circular surface 176, for threading into a radially inner internally threaded hole (not shown) in a left wall of an ejector suction chamber. Right wall 28c is a threaded unit for ease of disassembly from and reassembly to an ejector suction chamber. Although the construction as shown of each embodiment has many parts welded together it should be apparent that any method of assembly is suitable and the sections can be constructed of single pieces rather than the sub sections shown. Further, although the apparatus has been disclosed as used with steam it can also be utilized with air or any similar fluid or gas. While the invention has been described in its preferred embodiments, it is to be understood that the words which have been used are words of description rather than limitation and that changes may be made within the purview of the appended claims without departing from the true scope and spirit of the invention in its broader aspects.