US3801021A

US3801021A - Automatically adjustable expansion nozzle

Info

Publication number: US3801021A
Application number: US00216140A
Authority: US
Inventors: R Jakob
Original assignee: Bayer AG
Current assignee: Bayer AG
Priority date: 1971-01-29
Filing date: 1972-01-07
Publication date: 1974-04-02
Anticipated expiration: 1991-04-02
Also published as: DE2104197A1

Abstract

For expansion evaporation of liquids or gases an automatically adjustable nozzle is used, comprising a housing and a shaft arranged to be longitudinally displaceable therein, the shaft being provided at one end with a throttling member which in the closed position co-operates sealingly with a coacting member arranged on the end of the housing, the shaft being provided with a spring which is adjustable to a required closing pressure and being mounted frictionlessly in the housing.

Description

United States Patent 1 {111 3,801,021

Jakob Apr. 2, 1974 [5 AUTOMATICALLY ADJUSTABLE 2,978,870 4/1961 Vdoviak 239/570 x EXPANSION NOZZLE Inventor: Rolf Jakob, Leverkusen, Germany Bayer Aktiengesellschaft, Leverkusen, Germany Filed: Jan. 7, 1972 Appl. No.: 216,140

Assignee:

Foreign Application Priority Data Jan. 29, 1971 Germany 2104197 US. Cl. 239/571, 239/584 Int. Cl B05b 3/00 Field of Search 239/541, 570, 571, 533,

References Cited UNITED STATES PATENTS 6/1930 Groff 239/533 Primary Examiner-M. Henson Wood, Jr. Assistant Examiner-Andres Kashnikow Attorney, Agent, or Firm-Burgess, Dinklage &

Sprung [57] ABSTRACT For expansion evaporation of liquids or gases an automatically adjustable nozzle is used, comprising a housing and a shaft arranged to be longitudinally displaceable therein, the shaft being provided at one end with a throttling member which in the closed position cooperates sealingly with a coacting member arranged on the end of the housing, the shaft being provided with a spring which is adjustable to a required closing pressure and being mounted frictionlessly in the hous- 14 Claims, 4 Drawing Figures PATENTEDAPR 2 I974 F/GZ A-B FIG.

SHEET 1 OF 2 PATENTED 2 I974 SHEET 2 BF 2 F/G4 c-0 AUTOMATICALLY ADJUSTABLE EXPANSION NOZZLE The present invention relates to an automatically adjustable expansion nozzle for liquids or gases, the nozzle comprising a housing and a shaft arranged to be displaceable longitudinally therein, the shaft being provided at one end with a throttling member which cooperates in a sealing manner in the closed position with a coacting member arranged on the end of the housing, and the shaft being provided with a spring adjustable to a required closing pressure.

Such expansion nozzles are used for example for expansion evaporation, in which a solution which is to be concentrated by evaporation is heated under pressure and is then expanded to a lower pressure by means of the expansion nozzle. Some of the liquid is thereby spontaneously evaporated and in this way concentration of the solution occurs. The pressure in the preheater must in this case be larger than the vapour pressure of the liquid at the highest temperature which occurs, so that a premature evaporation in the preheater before the expansion and a consequential precipitation of solid substance and crust formation on the apparatus is prevented.

Arrangements are known in which an expansion valve capable of being throttled is used as setting member for regulating the flow rate. Such valves are automatically regulated in dependence upon the pressure in the preheater by means of pneumatic or electric auxiliary energy (in a closing regulating circuit). These regulating circuits are naturally complicated and susceptible to breakdown.

Consequently, it is the object of the present invention to provide an expansion nozzle which is automatically adjusted and is not dependent on regulation by means of a regulating circuit.

According to the present invention, there is provided an automatically adjustable expansion nozzle for the expansion evaporation of liquids or gases, comprising a housing and a shaft arranged to be longitudinally displaceable therein, the shaft being provided at one end with a throttling member which in the closed position co-operates sealingly with a coacting member arranged on the end ofthe housing, the shaft being provided with a spring which is adjustable to a required closing pressure and being mounted fictionlessly in the housing. The result obtained is that the shaft and the throttling member are not impeded in their movement by the stuffing boxes which surround the shaft and which are necessary according to the prior art. Thus no secondary forces act on the shaft and throttling member to alter the effect of the pressure of the liquid or gas on the valve member. If the shaft is for example guided through sealing stuffing boxes, the pressure between the stuffing box shaft cannot be defined, because it varies during operation.

According to a preferred embodiment, the shaft is provided with a disc against which the spring bears, and the shaft is adjustable longitudinally relatively to the housing by means of setting screws. The housing consists of two pipes sealed off relatively to one another and displaceable telescopically one within the other, and the setting screws are mounted in bearing elements fixed on the pipes. The effective length of the spring is adjustable by adjusting the length of the housing, so the nozzle can be regulated to an accurately defined opening pressure.

According to an, alternative prefered embodiment, the shaft comprises a screwthread which corresponds with the coacting thread of a disc, the shaft having at the other end a shaped extension which corresponds with a mating shaped extension of the stem of an adjusting lug. The stem of this adjusting lug is sealingly mounted in the housing. In comparison with the firstmentioned preferred embodiment, the advantage provided in that adjustment of the effective spring length can be achieved by adjustment of a single member, that is the shape extension, using the adjusting lug.

It is advantageous to provide a stop for the disc, so that firstly the spring is not damaged by suddenly occurring, undesirably high pressures, and secondly the nozzle can directly be tightly closed.

It is particularly advantageous for the throttling member, when in the closed position, only to bear with an annular line on the mating member. This is for example obtained by the fact that the throttling member and the associated mating member comprise different cone angles, so that the annular throughflow crosssection gradually narrows in the direction of flow. In this way, the hithertousual surface abutment of throttling member is avoided, because very often sticking phenomena are connected therewith which are caused for example by a drying solution.

Referring to the accompanying drawings:

FIG. 1 shows a longitudinal section of a first embodiment of an expansion nozzle,

FIG. 2 shows a section on the line A-B of FIG. 1,

FIG. 3 shows a longitudinal section of a second con structional form of an expansion nozzle, and

FIG. 4 shows a section on the line C-D of FIG. 3.

In FIGS. 1 and 2, a shaft 2 is shown arranged in a housing 1. A throttling member 3 is disposed at the bottom end of the shaft. The throttling member is formed as a truncated cone which increases in size towards the mouth. The throttling member 3 is secured by a nut 4. At the other end of the shaft, there is provided a thread 5 for a disc 7, having a corresponding thread 6. A compression spring 9 is arranged between the disc 7 and a shoulder 8 on the housing 1. In addition, a shaped extension 10 isarranged on the end of the shaft 2 which is provided with the mating thread 5, and a mating shaped extension 1 l on a stem 13 is fitted over said extension 10, a stem 13 being arranged along the extended axis of the shaft 2 and being sealed off by a stuffing box 12. The fit between the two shaped extensions l0 and 11 is very coarse, so that friction only occurs with adjustment. The disc 7 comprises two lugs 14, which engage in grooves 15 in the wall of the housing 1 and thus secure the disc 7 against turning movement. A stop or abutment 16 limits travel of the disc 7. A heating jacket 17 surrounds the upper part of the housing 1, and a second heating jacket 18 is arranged around the mouth portion of the housing 1 of the expansion nozzle. A guiding helix 19 is provided inside the heating jacket 18 for guiding the heating medium. The throttling member 3 bears, in the closed position, with an annular line contact of the nozzle against a mating element 20. The inlet bores are indicated at 21 (FIG. 2).

FIGS. 3 and 4 show an expansion nozzle of which the housing 22 consists of two

pipes

23 and 24 guided telescopically one within the other. Arranged on the outer pipe 23 is a stuffing box 25, which acts with a sealing action against the external surface of the pipe 24. A bearing element 26 fixed on the pipe 23 serves as a support for setting screws 27, which are mounted in a second bearing element 28 fixed on the pipe 24. The setting screws 27 each comprise two threaded members 29 and an adjusting nut 30. The bearing element 28 is designed as a flange, on which a cover cap 31 is flanged by means of a coacting flange 32 arranged thereon. A shaft 33 is arranged inside the

pipes

23,24 and inside the cover 31. At one of its ends, the shaft carries the tension spring 34 which is secured by means of a disc 35 and a screw 36. The compression spring 34 bears at one end against this disc 35 and at the other end it is supported on the bearing element 28. The second end of the shaft 33 extending through the bearing element 28 carries a cone-like throttling member 37 which, when the nozzle is closed, bears with a line contact against a mating member 38 which is arranged in the pipe 23. The medium to be treated enters through a supply inlet 39, which is provided in the cover 31 formed as a pipe extension.

In both embodiments, the medium, after entering at 21 and 39, respectively, flows through the slots 40 (FIG. 4) of the

parts

8 and 28, respectively, to the outlet end of the valve. Here the throttling member 3 or 37 opens under a pressure of the medium to which the

compression spring

9 or 34 is set.

I What we claim is:

1. An automatically adjustable expansion nozzle for the expansion evaporation of liquids or gases comprising:

a. a housing,

b. a shaft disposed in the housing and being longitudinally displaceable therein,

c. a throttling member mounted on the endof the shaft,

d. a seat for the throttling member mounted on the housing for cooperation with the throttling member for opening and sealingly closing of the nozzle,

e. a pressure spring within the housing working between the housing and shaft, urging the shaft to the closed position, and setting the closing pressure,

f. the shaft being unsealed in the housing other then for the seal between the throttling member and the seat when the nozzle is in the closed position,

g. a disc threaded onto the end of the shaft opposite the throttling member, the spring being interposed between the disc and the housing,

h. positioning means for selectively adjusting, the threaded location of the disc on the shaft to thereby selectively adjust the spring pressure,

i. said positioning means comprising a shaped shaft extension on the end of the shaft on which the disc is mounted, a matting shaped extension receiving the shaft shaped extension, a stem of the matting shaped extension extending through the housing. and means restraining rotation of the disc in the housing, whereby the pressure of the spring can be adjusted by wrenching action on the stem to thread the disc along the shaft.

2. An automatically adjustable expansion nozzle according to claim 1, the housing comprising two pipes in telescoping relation, a bearing element mounted on each pipe, adjustable setting screws interconnecting the bearing elements, whereby the overall length of the two pipes can be adjusted for selectively adjusting the length of the housing for in turn adjusting the spring pressure.

3. An automatically adjustable expansion nozzle according to claim 1, a stop mounted on the housing for limiting opening movement of the spring.

4. An automatically adjustable expansion nozzle according to claim 1, wherein the throttling member when in the closed position bears against the seat only along an annular line.

5. An automatically adjustable expansion nozzle according to claim 1 the shaft being unsealed as aforesaid by a stuffing box.

6. An automatically adjustable expansion nozzle according to claim 2, a stop mounted on the housing for limiting opening movement of the spring.

7. An automatically adjustable expansion nozzle according to claim 2, wherein the throttling member when in the closed position bears against the seat only along an annular line.

8. An automatically adjustable expansion nozzle according to claim 3, the shaft being unsealed as aforesaid by a stuffing box.

9. An automatically adjustable expansion nozzle according to claim 3, wherein the throttling member when in the closed position bears against the seat only along an annular line.

10. An automatically adjustable expansion nozzle according to claim 4, the shaft being unsealed as aforesaid by a stuffing box.

1 1. An automatically adjustable expansion nozzle according to claim 5, wherein the throttling member when in the closed position bears against the seat only along an annular line.

12. An automatically adjustable expansion nozzle according to claim 8 wherein the throttling member when in the closed position bears against the seat only along an annular line.

13. An automatically adjustable expansion nozzle according to claim 9, a stop mounted on the housing for limiting opening movement of the spring.

14. An automatically adjustable expansion nozzle according to claim 10, wherein the throttling member when in the closed position bears against the seat only along an annular line.

Claims

1. An automatically adjustable expansion nozzle for the expansion evaporation of liquids or gases comprising: a. a housing, b. a shaft disposed in the housing and being longitudinally displaceable therein, c. a throttling member mounted on the end of the shaft, d. a seat for the throttling member mounted on the housing for cooperation with the throttling member for opening and sealingly closing of the nozzle, e. a pressure spring within the housing working between the housing and shaft, urging the shaft to the closed position, and setting the closing pressure, f. the shaft being unsealed in the housing other then for the seal between the throttling member and the seat when the nozzle is in the closed position, g. a disc threaded onto the end of the shaft opposite the throttling member, the spring being interposed between the disc and the housing, h. positioning means for selectively adjusting the threaded location of the disc on the shaft to thereby selectively adjust the spring pressure, i. said positioning means comprising a shaped shaft extension on the end of the shaft on which the disc is mounted, a matting shaped extension receiving the shaft shaped extension, a stem of the matting shaped extension extending through the housing, and means restraining rotation of the disc in the housing, whereby the pressure of the spring can be adjusted by wrenching action on the stem to thread the disc along the shaft.

11. An automatically adjustable expansion nozzle according to claim 5, wherein the throttling member when in the closed position bears against the seat only along an annular line.