US2018474A - Centrifugal separator - Google Patents

Description

Oct. 22, 1935. J. F. THoLL 2,018,474

CENTRIFUGAL SEPARATOR Filed Dec. 2l, 1932 2 Sheets-Sheet l Oct. 22, 1935. J. F. THoLl. 2,018,474

CENTRIFUGAL S EPARATOR Filed Dec. 2l, 1932 2 Sheets-Sheet 2 /Vl/E/v TO R Patented Oct. 22, 1935 PATENT OFFICE CENTRIFUGAL SEPARATOR John F. Tholl, Needham, Mass., assignor to American Tool and Machine Company, Boston, Mass., a corporation of Massachusetts Application December 21, 1932, Serial No. 648,221 6 claims. (c1. 21o-63) In using centrifugal separators it is frequently the case that the material operated on will give oil' gases, vapors, or fumes which should be excluded from the room in which the machines are operating. The present invention deals with this problem and aims to devise a thoroughly practical solution for it.

The nature of the invention will be readily understood from the following description when read in connection with the accompanying drawings, and the novel features will be particularly pointed out inthe appended claims. l

In the drawings,

Figure l is a vertical, sectional view of a common type of centrifugal separator modified, however, to embody features of this invention;

Fig. 2 is a view similar to Fig. 1 of a centrifugal separator of another type constructed in accordance with this invention; and

Fig. 3 is a sectional View showing a detail of construction of the machine illustrated in-Fig. l.

Referring i-lrst to Fig. l which illustrates a. separator of the Well known Weston design, it will be seen that this machine includes a basket 2 of a common type mounted on the upper end of a rotary shaft 3. Surrounding the basket is a. stationary casing including the usual curb 4 supported on the base of the machine in a manner common in machines of this type.

In order to prevent the escape of gases, fumes, or the like, from the casing while the machine is ln operation, the top of the casing is closed by a plate 5 which is bolted to the casing ring a, a gasket 6 being interposed between the margin of the plate and the ring so as to provide a substantially gas tight connection at this point. Gases can still escape, however, thro-ugh the opening 'l provided in the bottom of the casing for the passage of the shaft 3, or some equivalent rotating member. It is impracticable to close this opening with a stuffing box through which the shaft or the hub of the basket will extend for the reason that the shaft has a very substantial oscillatory or gyratory motion, particularly in going through certain critical speeds as it comes up to normal speed or slows down. It is this fact which introduces the chief problem in making agas tight connection between the casing and the shaft. i

According to the present invention this object may be accomplished by closing the greater part of the opening at the bottom of the casing by means Voi a plate 8, in this particular instance made of dish shape in order to avoid interference with the hub 9. The inner margin of this plate is vshaft and the collar.

riveted to a collar I through which the shaft 3 extends, a running t being provided between the Midway between the ends of the collar the bore thereof is gTooved to provide an annular recess I2 for holding a body of 5 grease or similar material which serves both to lubricate the friction surfaces of the shaft and collar and also to prevent any substantial leakage of gas through the connection between these parts. Grease may be forced into the groove I2 l0 through an Alemite fitting I3.

The outer margin of the plate 8 bears against the lower surface o-f the curb 4. Overlapping said margin is a ring I4 which is secured to the curb by a series of bolts. An annular groove I l5 is formed in the ring to hold a body of lubricant in contact with the edge of the plate, the ring being equipped with an Alemite fitting I6, or' equivalent device, through which the lubricant can be forced into the groove. Preferably the upper margin of the inner edge of the ring I4 is spaced from the lower surface of the curb 4 by a distance afew thousandths of an inch greater than the thickness of the plate 8, as best shown in Fig. 3, thus providing a slip connection between the plate and the casing so that the plate can oscillate or gyrate with the shaft 3 without impeding substantially the lateral movements of the plate produced in this manner. Nothwithstanding such movements the joint between the margin of the plate and the casing is kept constantly sealed against any substantial leakage of gases therethrough by the grease or other lubricating medium I 5.

When the machine is in operation the liquid constituents of the load are thrown through the foraminous wall of the basket by the action of centrifugal force, and the liquids so extracted drain into the curb 4 and are drawn off through one or more of the hollow posts or standards Il 0 which support the casing, suitable pipes or conduits being connected to the lower ends of these posts to conduct the liquid away to the desired point.

This arrangement thus confines the gases and 5 vapors to the space inside the casing and to the conduits for conducting them away while the machine is in operation and eifectually prevents such gases and vapors from escaping into .the room where the attendants must work.

Fig. 2 shows the invention applied to a centrifugal separator of the suspended type, the parts corresponding to those shown in Fig. 1 being designated by the same, but primed, numerals. Since this machine also is of the well known Weston design no description of it is required. It will be observed, however, that the basket 2' is suspended from overhead and is revolved by its connections with the hollow shaft 3'. The closure plate 8' in this case isapplied to the top of the casing 4' instead of to the bottom, as inthemachine shown in Fig. 1, and it is connected to the shaft 3 and to the casing ring a.' in the same manner as in the construction previously described. In order to facilitate the loading of the basket a hole I8 is formed through the plate 8', this hole normally being closed by a cover 20 held` in place by thumb screws, bolts, or in any other suitable manner.

In using this machine the liquid content of the charge or load drains through the outlet 2l and is conducted by pipe connections 22 to a sump, tank, or any other convenient receptacle. Usually the casing of a machine of this type is extended downwardly to join that of a second machine into which the solid constituents of the load are dis' charged, so that it is not necessary to provide a second closure for the opening in the bottom of the casing corresponding to that shown at 5 in Fig. 1. However, the machine can be equipped with such a closure if desired. Naturally such details will vary with the requirements of individual installations, Usually the pipe 22 which carries away the liquid `,will be provided with a trap through which the liquid will be discharged.

In4 the event that the fumes or vapors given off from the materials undergoing treatment have toxic properties, or are injurious for any reason, exhaust connections will be provided between the conduits I'l and 22 and the stack or an exhaust blower for discharging them at some point outside the plant.

A somewhat different arrangement for closing the top of the casing 4 in the arrangement shown in Fig. 1 is illustrated in Fig. 4. It includes a circular member 23 of channel section secured to the upper casing ring a and surrounding the aperture in said ring. A plate 24 closes the aperture in the casing top and is provided with a circular downwardly bent marginal flange 25 resting on the bottom of the groove in the channel member 23. The weight of the cover serves to hold it in place. In order to make the seal produced in this manner even more effective, the groove in the channel member may be partly filled with some sealing liquid, such as Water, a. heavy oil, wax, or the like. The cover 24 can simply be lifted out of place when it is desired to load or unload the basket.

While I have herein shown and described typical embodiments of myinvention, it will be understood that these disclosures have been made rather by way of illustration than limitation, and that the invention may be embodied in other forms without departing from the spirit or scope thereof. In fact, many'of the details of construction necessarily will be varied in 'accordance with the design of the individual machine to which the invention is applied or to the conditions under which it is used.

Having thus described my invention, what I desire to claim as new is:

1. In a centrifugal separator, the combination with a basket and a shaft supporting said basket for rapid rotation, of a casing surrounding the basket, said casing having an opening for the passage therethrough of said shaft, and a' substantially rigid closure for said opening having a rotary but substantially gas tight connection with said shaft anda laterally slidable but substantially gas tight connection with said casing.

2. In a centrifugal separator, the combination with a basket and a shaft supporting said basket 5 for rapidrotation, of a casing Asurrounding the basket, said casing having an opening'for the passage therethrough of said shaft, a substantially rigid closure for said opening having a rotary connection with said shaft and a laterally 1n slidable connection with said casing, and means for lubricating both of said connections to provide an approximately gas tight seal at both of them.

3. In a centrifugal separator, the combination with a basket and a shaft supporting said basket for' rapid rotation, of a casing surrounding the basket, said casing having an opening for the passage therethrough of said shaft, a circular closure plate for said opening, ,said shaft extending through said plate, means providing a running but approximately gas tight fit between said plate and said shaft but serving to cause said plate to oscillate with said shaft, and an approximately gas tight slip connection between said casing and z5 the outer margin of said plate.

4. In a centrifugal separator, the combinationv with a basket and a shaft supporting said basket for rapid rotation, of a casing surrounding the basket, said casing having an opening for the passage therethrough of said shaft, a circular closure plate for said opening, said shaft extending through. said plate, means providing a running but approximately gas tight nt between said plate and said shaft but serving'to cause said 35 plate to oscillate with said shaft, parts cooperating with said casing to provide a groove into which the entire outer edge of said plate projects, and yielding material engaging the outer margin of said plate to make an approximately gas tight o joint between said plate and said casing.

5. In a centrifugal separator, the combination with a basket and a shaft supporting said basket for rapid rotation, of a casing surrounding the basket, said casing having an opening for the passage therethrough of said shaft, a circular closure plate for said opening, said shaft extending through said plate, a collar through which said shaft extends and with which it has a running fit, said collar being secured to said plate and having an annular internal chamber surroundin said shaft for holding a supply of sealing lubricant in contact with the shaft, and a ring carried by said casing and overlapping the outer margin of said plate to provide a laterally slidable connection between said plate and said casing, said ring having an annular recess to hold lubricating material in contact with the .edge of said plate to lubricate said slidable connection and to seal it against the leakage of gases therethrough.

6. In a centrifugal separator, the combination with a basket and a shaft supporting said basket for rapid rotation, of a casing surrounding said basket, said casing having an opening in one end thereof for the passage therethrough of said u shaft, a closure for said opening, and means providing substantially gas tight joints connecting` said closure with said casing and also with said shaft, one of said joints being constructed to provide a lateral slip to accommodate the gyratory 7 movements of said shaft. A

JoHN i'. THOLL.

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