US3795362A

US3795362A - Centrifuge bowl having an improved nozzle assembly

Info

Publication number: US3795362A
Application number: US00258797A
Authority: US
Inventors: J Caldwell; L Shapiro
Original assignee: Pennwalt Corp
Current assignee: Alfa Laval AB
Priority date: 1972-05-31
Filing date: 1972-05-31
Publication date: 1974-03-05
Anticipated expiration: 1991-03-05
Also published as: SE395227B; CA959807A; IT984943B; FR2186297B1; DE2322491A1; FR2186297A1; GB1401162A; JPS4950562A

Abstract

A nozzle assembly has a retainer sleeve, a nozzle holder, and a nozzle. The sleeve is pushed into an opening in the bowl from the interior thereof, and is keyed into place. The holder is pushed into the sleeve from the exterior of the bowl, and is locked into place (by rotation) by a bayonet type connection. A protrusion on the interior of the sleeve serves to stop the rotation of the holder in extreme positions, i.e., a fully locked position and a fully unlocked position. The nozzle is threadably mounted in the outer end of the holder, and is arranged so as to be aligned in a predetermined direction with respect to the bowl when the holder is in its fully locked position. An annular boss is formed on the holder between the bayonet connection and the nozzle, the boss being slidably mounted within the sleeve and serving to guide and support the holder while simultaneously shielding the bayonet connection.

Description

tlnited States Patent [1 1 fialdwell et al.

3,795,362 Mar. 5, 1974 CENTRHIUGE BOWL HAVING AN IMPROVED NOZZLE ASSEMBLY- [75] Inventors: John Warren Caldwell, Glensitle;

Leonard Shapiro, Upper Darby, both of Pa.

[73] Assignee: lPennwalt Corporation, Philadelphia,

[22] Filed: May 31, 1972 [21] Appl. No.: 258,797

52 us. Cl. 233/20 R, 233/47 R [51] Int. Cl B04b' 1/12 [58] Field of Search 233/20 R, 46, 47 R [56] References Cited UNITED STATES PATENTS 3,075,696 l/l963 Fitzsimmons 233/47 R 2,911,139 Il /1959 Johnson 233/47 R FOREIGN PATENTS OR APPLICATIONS 605,597 l1/l934 Germany 233/47 R A Primary Examiner-George H. Krizmanich Attorney, Agent, or Firm-Edward A. Sager [57] ABSTRACT A nozzle assembly has a retainer sleeve, a nozzle holder, and a nozzle. The sleeve is pushed into an opening in the bowl from the interior thereof, and is keyed into place. The holder is pushed into the sleeve from the exterior of the bowl, and is locked into place (by rotation) by a bayonet type connection. A protrusion on the interior of the sleeve serves to stop the rotation of the holder in extreme positions, i.e., a fully locked position and a fully unlocked position. The nozzle is threadably mounted in the outer end of the holder, and is arranged so as to be aligned in a predetermined direction with respect to the bowl when the holder is in its fully locked position. An annular boss is formed on the holder between the bayonet connection and the nozzle, the boss being slidably mounted within the sleeve and serving to guide and support the holder while simultaneously shielding the bayonet connection.

15 Claims, 5 Drawing Figures ll CENTRIFUGE BOWL HAVING AN IM?ROVED NOZZLE ASSEMBLY BACKGROUND OF THE INVENTION In clarifying liquids contaminated with heavier solid particles, disc type centrifuges are used. In order to continually discharge the solids whichare deposited on the interior periphery of the centrifuge bowl during rotation thereof, the bowl is shaped so that solids are propelled toward nozzle assemblies mounted within openings formed in the bowl; solids along with some liquid are discharged through these nozzle assemblies.

A nozzle per se should be constructed from an abrasion resistant material. Often, the nozzle is brazed into a nozzle holder, as opposed to being removably mounted therein by threads, a bayonet type connection, or similar means. Consequently, when the nozzle becomes worn, the entire nozzle holder must be discarded, or the worn nozzle removed and replaced with a new one which involves a rebrazing operation. By removably mounting the nozzle in the nozzle holder, it can be readily inserted and removed from the exterior of the nozzle holder without removing the latter from the retainer sleeve, thus facilitating cleaning of the assembly, and nozzle replacement.

Another means which is used for mounting the nozzle into the nozzle holder is by taper locking the nozzle into a tapered hole in the nozzle holder, as illustrated in U.S. Pat. No. 3,075,696. With this construction, however, the seal around the nozzle is dependent upon the quality of the fit between the nozzle and the nozzle holder. Any dirt or other foreign material on the tapers might produce leakage. Such tapered fits are also ex pensive to manufacture.

Where nozzle holders having removably mounted nozzles mounted therein (e.g., by a threaded connection) have been used, these nozzle holders have been held within a retainer sleeve by a second threaded locking sleeve, the retainer sleeve being keyed into the opening formed in the bowl. Use of such a threaded locking sleeve requires considerable time for installation and removal of the nozzle holder, and also requires care in handling the fine threads so as to prevent damage thereto. When installing the nozzle holder in a dirty environment, care must also be exercised so as to keep the threads clean.

It is desirable that the nozzle holder have the capability of being quickly installed from exterior of the bowl without using a threaded connection. Where this has been done with a connecting lug and groove arrangement, however, no means has been provided to shield the connecting lug and groove from the surrounding environment so as to prevent the buildup of solid materials on the connecting lug and groove (e.g., see U.S. Pat. No. 2,695,748).

Consequently, what is needed is an embodiment of a centrifuge bowl having an improved nozzle assembly which solves the above listed problems and others by having at least the following features in various combi nations:

a. a centrifuge bowl having a nozzle assembly wherein the nozzle holder can be mounted within a retainer sleeve from the exterior of the bowl by means of a bayonet type connection, and wherein means are provided for shielding the bayonet connection from foreign materials, and for supporting the nozzle holder within the retainer sleeve.

b. a retainer sleeve which is removably mounted within an opening in the centrifuge bowl.

0. a removably mounted nozzle which can be readily separated from the nozzle holder for cleaning and replacement.

d. means for stopping the nozzle holder in both locked and unlocked positions within the retainer sleeve.

These features and others are clearly set forth both in the description which follows below, and the drawrngs.

SUMMARY OF THE INVENTION The present invention relates to a centrifuge bowl having an improved nozzle assembly mounted therein. The nozzle assembly is comprised of 3 main components, a retainer sleeve, a nozzle holder, and a nozzle. Such a nozzle assembly might be incorporated, for example, into a disc type centrifuge as illustrated in U.S. Pat. No. 3,075,696.

The retainer sleeve is pushed into an opening in the centrifuge bowl from the interior of the bowl, and is aligned and held in a predetermined angular position by means of a key and'groove arrangement. A shoulder formed on the outer periphery of the retainer sleeve prevents the latter from being propelled outwardly during rotation of the bowl. A sealing ring is mounted between the centrifuge bowl and retainer sleeve to prevent leakage around the latter.

A nozzle holder has a nozzle threadably mounted in the outer end thereof; a sealing ring is mounted between them to prevent leakage around the nozzle. To mount the nozzle holder within the retainer sleeve, a bayonet type connection is used by forming a lug on the nozzle holder which cooperates with a channel formed in the retainer sleeve after the nozzle holder is pushed into the retainer sleeve to a position permitting rotation between the two. The nozzle holder is dimensioned so as to have a slidable fit with the inner portion of the interior of the retainer sleeve; a sealing ring is mounted between the two to prevent leakage around the nozzle holder. A first protrusion angularly aligns the retainer sleeve within the opening in the centrifuge bowl. A second protrusion on the interior of the retainer sleeve is positioned so as to stop the nozzle holder in two extreme positions, a fully unlocked and a fully locked position.

The nozzle holder is also provided with an annular boss which extends around the outer periphery thereof, the annular boss being positioned so that the outer face thereof is flush with the outer end of the retainer sleeve when the nozzle holder has been pushed inwardly to a position where the lug on the nozzle holder can be rotated into the channel in the retainer sleeve. The annular boss is dimensioned so as to have a slidable fit with respect to the outer portion of the interior of the retainer sleeve, thus supporting the nozzle holder, and shielding or sealing the bayonet connection from foreign materials, and from the material being discharged through the nozzle. A tool engaging slot formed on the outer end of the nozzle holder is arranged to visually indicate when the nozzle holder has been rotated to its fully locked position.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates an exploded view of an embodiment of the nozzle assembly.

FIG. 2 illustrates a cross-sectional view of an embodiment of the invention taken through the centrifuge bowl and retainer sleeve, showing the nozzle assembly in its mounted condition.

FIG. 3 is a cross-sectional view taken through line 3-3 of FIG. 2, showing the key which aligns and holds the retainer sleeve in a predetermined angular position within the opening in the centrifuge bowl, and showing how one end of the lug on the nozzle holder abuts one side of the key when the nozzle holder is in a fullylocked position.

FIG. 4 is a cross-sectional view taken through line 4-4 of FIG. 2.

FIG. 5 is a cross-sectional view taken through line 5-5 of FIG. 2, showing the nozzle in its mounted condition, and showing the detailed construction of the nozzle.

DETAILED DESCRIPTION OF THE INVENTION As stated above, the present invention relates to a centrifuge bowl having an improved nozzle assembly for discharging heavy phase material which has been separated within the separation chamber. Referring to FIGS. 1 and 2, it can be seen that the main components of nozzle assembly comprise a retainer sleeve 11, a nozzle holder 12, and a nozzle 14.

As used herein, if a first element is said to be slidably mounted within a second element, it means that the first element is dimensioned so as to have a slidable fit within the second element; as opposed to threadably mounted, it also means that the first element can be inserted into or withdrawn from the second element by pushing or pulling the first element respectively.

Sleeve 11 is slidably mounted with an interference fit within an opening 16 formed in centrifuge bowl 18 by pushing the sleeve into the opening from the inside of the bowl; as can be seen, sleevell will move outwardly until an annular surface 20 of annular shoulder 22 formed on the outer periphery of sleeve 11 abuts annular surface 24 of annular shoulder 26 defined by the opening 16. To prevent leakage around the sleeve 11, a sealing ring 28 is mounted between the sleeve and bowl 18.

Formed on the interior of sleeve 11 is a lug 30, which together with the annular surface 32 of shoulder 34, defines a channel 36, the latter being sized so as to accept a complementary lug 38 on holder 12 so as to lock the latter into the sleeve.

To lock holder 12 into place within the sleeve 11, the former is pushed into the latter from the exterior of bowl 18, slidably mounting the circular portion 40 within the inner portion 42 of sleeve 11. To prevent leakage around holder 12, a sealing ring 43 is mounted between sleeve 11 and holder 12. Holder 12 will move inwardly until the inner surface 44 of lug 38 abuts annular surface 32 of shoulder 34. In this position, the holder 12 is rotated as viewed in FIG. 1 so as to rotate lug 38 into channel 36. The holder will rotate until the end 46 of'lug 38 abuts side 48 of key 50, at which point, the holder is in a fully locked position (see FIG. 3 also). When it is desired to unlock and remove the holder 12 from sleeve 11, the holder is rotated in the opposite direction, rotating lug 38 out of channel 36 until the other end 52 of lug 38 abuts the other side 54 of key 50, at which point the holder is in a fully unlocked position. At this point, holder 12 can be pulled from sleeve 11. To assist in rotating holder 12, a slot 56 is formed on the outer end thereof for engaging a screwdriver or other tool; the slot is arranged so that it will also provide a visual indication of when the holder is in its fully locked position, the slot having a known alignment when holder 12 is so positioned.

I-Iolder 12 is also provided with an annular boss 58 which is slidably mounted within the outer portion 60 of the sleeve, this boss serving to guide and support holder 12 within the sleeve, and also to shield the interior of the sleeve from the material being discharged through nozzle 14. Although sealing ring 62 is shown mounted between annular boss 58 and retainer sleeve 11, this may be omitted if desired. To provide a visual indication of when holder 12 has been pushed inwardly into sleeve 11 to an axial position where lug 38 can be rotated into channel 36, boss 58 is arranged so that the outer face 64 thereof is flush with the end 66 of sleeve 11 when this position is reached, i.e., when inner surface 44 of lug 38 abuts annular surface 32.

Referring to FIG. 5, it can be seen that nozzle 14 includes an abrasion resistant insert 68 which is secured within an outer casing 70 by an epoxy glue or other means, the casing being threadably mounted in nozzle holder 12. Formed on the outer end of casing 70 is a lateral extension 72 which extends around the periphery thereof. To prevent leakage around the nozzle, a sealing ring 74 is mounted between the holder 12 and lateral extension 72.

Since there are a plurality of nozzle assemblies arranged around a centrifuge bowl, it is desirable that each discharge the separated heavy phase material in the same direction with respect to the bowl. Thus, each assembly is mounted within the bowl so as to discharge material in a predetermined direction with respect thereto. In the present embodiment, this predetermined direction is outwardly at an acute angle from a vertical plane which is tangent to the outer periphery of bowl 18 at the centerline of opening 16 (see FIG. 2), and downwardly at an acute angle from a horizontal plane extending through the same centerline (see FIG. 5). It is to be understood that this predetermined direction is not fixed and may be varied if desired. The material is discharged so as to optimize power recovery and minimize contact with the exterior of the bowl and the other nozzle assemblies. Thus, material will be discharged from separation chamber 75 via passageway 77 and nozzle outlet 79, the latter being disposed so as to discharge the material in the predetermined direction when the assembly is properly mounted within opening 16.

To mount nozzle assembly 10 within bowl 18 so that nozzle 14 faces in its predetermined direction with respect to the bowl, key 50 is extended completely through retainer sleeve 11 so as to cooperate with a complementary groove 78 (See FIGS. 3 and 4). Thus, sleeve 11 is aligned and held in a predetermined angular position within opening 16. By properly designing and arranging nozzle 14, lug 30, lug 38, and key 50 with respect to each other, nozzle 14 will be disposed in its proper predetermined discharge position with respect to bowl 18 when sleeve 11 is mounted within opening 16 as shown with holder 12 moved to its fully locked position. Although not so limited, each of the

lugs

30 and 38 extend'approximately 160 around in the present embodiment. in the present embodiment, abutting shoulders 22 and 26 (see FIG. 2) are the primary means utilized for holding sleeve 11 in a predetermined axial position during rotation of bowl 18, i.e., for preventing the sleeve from being propelled outwardly via centrifugal force. It is noted, however, that key 50 and complementary groove 78 (see FIG. 4) would also prevent sleeve 11 from being propelled outwardly during rotation of bowl 18. Consequently, within the scope of the present invention, shoulders 22 and 26 could be eliminated, and one or more keys and grooves or other means could be utilized for holding sleeve 11 in a predetermined axial position during rotation of bowl 18. It is also within the scope of the present invention to form the nozzle within the nozzle holder by drilling or otherwise forming a suitable opening in the nozzle holder.

We claim:

1. The combination with a centrifuge bowl defining a separation chamber, wherein said bowl is adapted to rotate about an axis of rotation and has an opening extending therethrough for the outward discharge of heavy phase material separated within said chamber, of a nozzle assembly, said assembly comprising a retainer sleeve which is slidably mounted within said opening, means for holding said sleeve in a predetermined angular and axial position within said'opening during rotation of said how], a nozzle holder having a portion of circular cross-section, said holder portion being slidably mounted within the inner portion of the interior of said sleeve, said assembly having means for locking said holder against axial movement with respect to said sleeve by rotating said holder in one direction after said holder portion has been pushed inwardly to a predetermined position within said inner portion, and means for stopping said holder in a fully locked position by stopping said rotation thereof in said first direction at a predetermined point.

2. The combination as set forth in claim 1, said nozzle assembly further including means defining a nozzle within said holder outwardly from the outer end of said sleeve, said nozzle, said locking means, and said stopping means each' being disposed with respect to each other so that when said holder is rotated to its fullylocked position, said nozzle will be in a predetermined discharge position with respect to said bowl,

3. The combination as set forth in claim 2, said holder being adapted to be unlocked by rotating said holder in the other direction, and further including means for stopping said holder in a fully unlocked position, in which said holder can be pulled out of said sleeve, by stopping said rotation in said other direction at a predetermined point.

4. The combination as set forth in claim 3, wherein said holder has an annular boss disposed around the pe riphery thereof and located between said locking means and said nozzle, said boss being slidably mounted within the outer portion of the interior of said sleeve.

5. The combination as set forth in claim 4, wherein said nozzle is removably mounted within said holder.

6. The combination as set forth in claim 5, wherein the outer face of said boss is flush with the outer end of said sleeve when said holder is in an axial position with respect to said sleeve so as to permit said holder to be locked within said sleeve.

' 7. The combination as set forth in claim 6, wherein said means for holding said sleeve in said predetermined angular position within said opening, and both said stopping means, comprise a first protrusion and a second protrusion extending from said sleeve.

8. The combination as set forth in claim 7 and further including sealing rings mounted between said bowl and said sleeve, between said sleeve and said holder portion, and between said holder and said nozzle.

9. The combination as set forth in claim 8, wherein said opening defines a first annular shoulder having an annular inwardly facing surface, wherein said sleeve has a second annular shoulder having an annular outwardly facing surface formed on the outer periphery of said sleeve, wherein said first and second shoulders abut each other, wherein said means for holding said sleeve in said predetermined axial position within said opening comprises said first and second shoulders, wherein said nozzle has an abrasion resistant insert secured therein, wherein the outer end of said nozzle has a lateral extension formed around its periphery, and further including a sealing ring mounted between said extension and said holder.

10. The combination as set forth in claim 9, and further including means formed on said holder for engagement by a tool for rotating said holder during the locking and unlockingthereof, said engagement means being disposed so as to simultaneously visually indicate when said holder is in its fully locked position.

ll 1. The combination as set forth in claim 10, and further including a sealing ring mounted between said boss and said outer portion of said sleeve.

12. The combination as set forth in claim 5, and further including sealing rings mounted between said bowl and said sleeve, between said sleeve and said holder, and between said holder and said nozzle, said nozzle having an abrasion resistant insert secured therein.

13. The combination as set forth in claim 3, wherein said nozzle is removably mounted within said holder.

14. The combination as set forth in claim 3, wherein said opening defines a first annular shoulder having an annular inwardly facing surface, wherein said sleeve has a second annular shoulder having an annular outwardly facing surface formed on the outer periphery of said sleeve, wherein said first and second shoulders abut each other, and wherein said means for holding said sleeve in said predetermined axial position within said opening comprises said first and second shoulders.

15. The combination as set forth in claim 3, and further including means formed on said holder for engagement by a tool for rotating said holder during the locking and unlocking thereof, said engagement means being disposed so as to simultaneously visually indicate when said holder is in its fully locked position.

Claims

1. The combination with a centrifuge bowl defining a separation chamber, wherein said bowl is adapted to rotate about an axis of rotation and has an opening extending therethrough for the outward discharge of heavy phase material separated within said chamber, of a nozzle assembly, said assembly comprising a retainer sleeve which is slidably mounted within said opening, means for holding said sleeve in a predetermined angular and axial position within said opening during rotation of said bowl, a nozzle hOlder having a portion of circular cross-section, said holder portion being slidably mounted within the inner portion of the interior of said sleeve, said assembly having means for locking said holder against axial movement with respect to said sleeve by rotating said holder in one direction after said holder portion has been pushed inwardly to a predetermined position within said inner portion, and means for stopping said holder in a fully locked position by stopping said rotation thereof in said first direction at a predetermined point.

2. The combination as set forth in claim 1, said nozzle assembly further including means defining a nozzle within said holder outwardly from the outer end of said sleeve, said nozzle, said locking means, and said stopping means each being disposed with respect to each other so that when said holder is rotated to its fully-locked position, said nozzle will be in a predetermined discharge position with respect to said bowl.

4. The combination as set forth in claim 3, wherein said holder has an annular boss disposed around the periphery thereof and located between said locking means and said nozzle, said boss being slidably mounted within the outer portion of the interior of said sleeve.

7. The combination as set forth in claim 6, wherein said means for holding said sleeve in said predetermined angular position within said opening, and both said stopping means, comprise a first protrusion and a second protrusion extending from said sleeve.

10. The combination as set forth in claim 9, and further including means formed on said holder for engagement by a tool for rotating said holder during the locking and unlocking thereof, said engagement means being disposed so as to simultaneously visually indicate when said holder is in its fully locked position.

11. The combination as set forth in claim 10, and further including a sealing ring mounted between said boss and said outer portion of said sleeve.