US2982417A - Vapor seal for gyratory centrifugal machines - Google Patents

Description

y 2, 1961 y H. DURRELL 2,982,417

VAPORSEAL FOR GYRATORY CENTRIFUGAL MACHINES Filed Sept. 9. 1957 INVENTOR.

6" BY H D ATTORNEYS United States Patent C VAPOR SEAL FOR GYRATORY CENTRIFUGAL MACHINES Harold Durrell, Cincinnati, Ohio, assignor to The Western States Machine Company, Hamilton, Ohio, a corporation of Utah Filed Sept. 9, 1957, Ser. No. 682,746

2'Claims. Cl. 210-366) Centrifugals of this type generally employ a large,

rotary basket which may be perforate or solid, so formed thatliquid-liquid or liquid-solid separation will be effected during rotation of a suspended spindle on which 'the basket is carried. As the load in the basket often is not evenly distributed, the rotation of the spindle, and basket during such process tends to be eccentric, so that an aperture in the top wall .of the curb which protects the basket must be of substantially larger diameter than the diameter of the spindle. Thus, the spindle motion may be gyratory without having the spindle contact the curb during rotation.

In many centrifugal processes which are performed in the chemical and related industries, thecharge material liberates toxic, explosive or disagreeable vapors. In such operations the vapors may be discharged through the necessary space between the spindle and the top wall of the curb, presenting a hazardous or undesirable condition.

The object of this invention is to provide a vapor seal for such centrifugal machines wherebyvapors liberated from charge material will be prevented from escaping between the curb and the spindle during either the stable rotation or the eccentric gyration of the basket and spindle. v

According to this invention the seal comprises two members, one of which is a container member-adapted to hold a body of liquid, which member is vertically elongated and open at the top thereof and has a bottom wall fixed to and sealed around the spindle for rotation therewith, and the other of which is a sealing member fixed to the top wall of the curb so as to remain stationary during rotation of the spindle. Thecontainer and the sealing member each surround the aperture in the top wall of the curb, and the sealing member surrounds the container member and extends radially in'wardly over the top thereof and has a vertically elongated annular wall extending between the container and the spindle to a position where it will be immersed in a body'of liquid in the container and will form a columnar annular space or chamber between itself and the spindle to receive the liquid displaced by any pressure of vapors, within the curb while the spindle is at. rest, and also will stay spaced from the spindle and the, container whenthe spindle is either rotating or at rest.

.The foregoing and other'objects, features and advantages of this invention will become more apparent in the following detailed description and the accompanying drawings illustrating a preferred embodiment thereof.

In the drawings:

Fig. 1 is a front elevation, partly broken away, of a heavy-duty centrifugal machine incorporating a vapor seal according to a preferred embodiment of the invention and;

Fig. 2 is an enlarged sectional view showing the vapor seal and details thereof. f

According to the illustrated embodiment, the invention is applied to a centrifugal machine, indicated generally at 10,'which employs a large, open-top basket 11 carried by a vertical spindle 12 suspended from. a gyratory centrifugal head 13 of suitable construction. The head 13 is supported below the framework 14. A motor 16 drives the spindle 12 and basket 11 through intermediate connections not shown. a

The basket 11 is enclosed by a curb 18 having a top wall 19 in which an aperture 20 has been formed to allow the spindle 12 to gyrate freely within the curb 18. The diameter of the aperture 20 is substantially larger than 25 the diameter of the spindle 12.

container member 22 adapted to hold a body of liquid 23.

Referring to Fig. 2, the vapor seal includes an annular The container 22 has an inturned annular rim 21 at its top, which rim is spaced from the spindle 12. The bottom wall of the container 22 is provided with a bushing or sleeve 24- which is firmly afiixed to the spindle 12 by conventional means such as aset screw 25. An O-ring 26 or other suitable means surrounds the spindle 12 within the sleeve 24 and seals the sleeve 24 against the spindle 12. In this arrangement the container 22 will rotatewith the spindle =12. V v The vapor seal also includes anannular sealing member indicated generally at 28, which is fixed to the top wall 19 of the curb 18 by means of cap screws 29 or the like. Sealing member 28 is gas impermeable and is formed with an outer annular wall 30 extending substantially vertically from the curb top 19, an intermediate wall 31 extending radially inwardly from the top of wall 30 toward the spindle 12, and a vertically elongated annular immersion wall 32 extending downwardly" from wall 31 in a direction substantially parallel to the wall 30 and the spindle 12, to a position where its lower edge will always be immersed in the body of liquid 23. The wall 32 isspaced from the spindle 12 so as to form a vertically elongated or columnar annular chamber 15 between itfirmly attached together. When it is desired to remove the vapor seal-from its position on the curb top wall 19,

According to a preferred embodiment of the invention,

An outwardly turned flange is provided near the the container 22 and member 28 may be disassembled and removed, to be'again assembled and the parts thereof reunited.

When the body of liquid 23 is at rest due to lack of rotation of the spindle 12 and there is no pressure upon the liquid from vapors within the basket and curb, the liquid level will be approximately that indicated at 36 and the annular wall 32 extends vertically into the liquid. However, when the spindle 12 rotates, the liquid 23 is forced outwardly by centrifugal force and tends to form a vertical parabolic wall of'liquid in the container, as indicated by the broken lines 37.

To assure continued contact of the annular wall 32 with the liquid 23 during spindle rotation, an outwardly turned flange 39 is fixed to the immersion wall 32 at the lower end thereof so that it projects into the liquid 23 for a suitable distance, but not so far as to touch the com tainer member 22 during gyration of the spindle 12.

Another eflect of the centrifugal force resulting from rapid rotation of the spindle 12 is the tendency of the liquid 23 to climb the wall of the container 22 and overflow the container. Such overflow is prevented by an inwardly turned flange 46 forming the inner part of the rim 21 of the container 22. The flange 40 extends a suitable distance toward the immersion wall 32 of the sealing member 28, but not so far as to touch that wall during gyration of the spindle In the operation of the machine gases within the curb 18 are able to pass upwardly through the aperture 20 in its top wall 19, but the described vapor seal prevents them from escaping when the basket and spindle are either rotating or at rest. Their flow is blocked by the barrier formed through the continuous immersion of wall 32 of the sealing member 28 in the body of liquid 23 held in the container 22. Due to the O-ring 26 such gases cannot flow between the bushing 24 and the spindle 12. When the spindle is at rest the pressure of vapors seeking to escape from within the curb displaces the body of liquid 23 downwardly in the container member 22 outside wall 132 and upwardly inside that wall to form a column of liquid within the annular space or chamber 15 between the wall 32 and the spindle 12. A disposition of the liquid such as will result from the maximum expectable pressure of vapors within the curb is indicated by the broken lines 3811 and 38b in Fig. 2, the line 38a representing schematically a liquid surface formed by pressure outside wall 32 and the line 38b representing a toplevel of the liquid column formed in space 15. The

space or chamber 15 is so extensive in the vertical direction that the liquid will not be forced out of it but will rise and remain in it and in immersing relation to the flange 39, thus preserving the sealing action under all conditions of operation of the machine.

It is to be understood that the detailed description and the accompanying drawing are illustrative and that the vapor seal herein disclosed may be embodied in various forms of construction without departing from the scope of the invention defined by the appended claims.

What is claimed is:

1. In combination with a centrifugal machine including a vertically suspended gyratory spindle carrying a centrifugal basket and a stationary curb surrounding said basket, said curb having a top wall formed with an aperture the margin of which is spaced from said spindle to permit free eccentric gyration of said spindle, sealing means for continuously preventing the escape of vapor between said wall and said spindle While the basket is either rotating or at rest, said sealing means comprising a rotary container member having a bottom wall fixed to and surrounding said spindle and having a vertically elongated annular side wall extending upwardly from said bottom wall in spaced relation to said spindle and forming therewith a vertically elongated gas-impervious annular trough to hold a body of liquid, said trough being open at the top thereof around said spindle and being always accessible through its top opening and through said aperture to vapors Within said basket and said curb, said annular side wall being formed with an inturned rim at the top to hold said body of liquid disposed vertically against said side wall when said spindle is rotating, and a stationary gas-impervious sealing member fixed to a part of said top wall surrounding said container member and said aperture and extending upwardly from said top wall part and then radially inwardly over the top of said rotary member and then downwardly into said trough to form a seal with said rotary member through tending part of said sealing member comprising a vertically elongated annular immersion wall extending downward through the open top of said trough in spaced relation to said inturned rim and to said spindle and terminating at its lower end in a radially outwardly extended circular edge disposed below the level assumed by said body of liquid when said spindle is at rest and disposed radially outside the outermost location of the inner surface of said body of liquid when said spindle is rotating, said immersion wall forming a vertically elongated annular chamber between itself and said spindle to retain a column of said liquid displaced into said chamber by pressure of vapors within said curb while said spindle is at rest, said sealing member being spaced throughout from said spindle and from said rotary member by a distance greater than the distance of gyration of said spindle in said aperture.

2. In combination with a centrifugal machine including a vertically suspended gyratory spindle carrying a centrifugal basket and a stationary curb surrounding said basket, said curb having a top wall formed with an aperture the margin of which is spaced from said spindle to permit free eccentric gyration of said spindle, sealing means for continuously preventing the escape of vapor between said top wall and said spindle while the basket is either rotating or at rest, said sealing means comprising a rotary container member having a bottom wall fixed to and surrounding said spindle and having a vertically elongated annular side wall extending upwardly from said bottom wall in spaced relation to said spindle and forming therewith a vertically elongated gas-impervious annular trough to hold a body of liquid, said trough being open at the top thereof around said spindle and being always accessible through its top opening and through said aperture to vapors within said basket and said curb, said annular side wall being formed with an inturned rim at the top to hold said body of liquid disposed vertically against said side wall when said spindle is rotating, and a stationary gas-impervious sealing member fixed to a part of said top wall surrounding said aperture and extending into said trough to form a seal with said rotary member through the body of liquid in said trough, said sealing member comprising a cylindrical supporting wall extending upwardly from said top wall part, an intermediate wall extending radially inwardly from the top of said supporting wall and a vertically elongated cylindrical immersion wall extending vertically downward from the inner edge of said intermediate wall through the open top of said trough in spaced relation to said inturned rim and said spindle, said immersion wall terminating at its lower end in a radially outwardly turned circular flange the outer edge of which is disposed below the level assumed by said body of liquid when said spindle is at rest and disposed radially outside the outermost location of the inner surface of said body of liquid when said spindle is rotating, said immersion wall forming a vertically elongated cylindrical chamber between itself and said spindle to retain a column of said liquid displaced into said chamber by pressure of vapors within said curb while said spindle is at rest, said sealing member being spaced throughout from said spindle and from I said rotary member by a distance greater than the disthe body of liquid in said trough, the downwardly extance of gyration of said spindle in said aperture.

. References Cited in the file of this patent UNITED STATES PATENTS 2,018,474 Tholl Oct. 22, 1935 2,044,996 Podbieluiak June 23, 1936 2,119,644 Miller June 7, 1938 FOREIGN PATENTS 21,623 Sweden Feb. 1, 1905 361,458 Great Britain Nov. 26, 1931 360,977 Italy July 9, 1938

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