Apparatus For Controlling The Discharge Of Separated Material In Centrifugal Drums Of Centrifugal Separators

Abstract

The discharge of separated components from centrifugal drum separators is controlled so that only a given component issues from its given outlet, despite changes in the proportions of the separated components. The centrifugal pressure in the drum is detected, to determine the position of the interface and to make appropriate outlet adjustments, or else a float that moves with the interface makes the needed outlet adjustments.

Description

The present invention relates to centrifugal separators, more particularly of the drum type in which separate outlets are provided for the components of liquid mixtures that are separated by centrifugal force according to their different specific gravities upon rotation of the drum.

When the ratio to each other of the components of such mixtures remains constant, then the discharge outlets can be accordingly positioned and no difficulty arises by virtue of one component discharging through the wrong outlet. But when the nature of the mixture or the proportion of the components changes, then some adjustment must be made of the outlets. This can be done by interchanging the parts, or by positioning movable tubes in the centrifugal drums that can be selectively immersed in the separated liquids to any desired depth.

A much more difficult task arises, however, if the proportion of the components to each other changes continuously. For example, in the case of a water-oil separation during cleanup operations on oil slicks on bodies of water, it is impossible to keep the water-oil proportion constant as it is fed into the separator. This is because the water is agitated and the separator intake also rises and falls relative to the water-oil interface, with the intake opening disposed now in the water layer and again in the oil layer. Thus, the feed to the separator in such an operation will sometimes be all water, sometimes all oil, and sometimes oil-water mixtures of varying proportion. Thus, with the equipment known heretofore, the discharge from either or both of the oil and water outlets of the drum will from time to time contain the wrong component, and the separation will be spoiled.

Accordingly, it is an object of the present invention to provide apparatus for controlling the discharge of separated material in centrifugal drums of centrifugal separators, in which the integrity of the separation is maintained despite fluctuating ratios of the components relative to each other as fed to the separator.

Another object of the present invention is the provision of apparatus for controlling the discharge of separated material in centrifugal drums of centrifugal separators, which is automatically responsive to changes in proportion of the separated components relative to each other so as to maintain the integrity of the separately discharged components.

Finally, it is an object of the present invention to provide apparatus for controlling the discharge of separated material in centrifugal drums of centrifugal separators, which will be relatively simple and inexpensive to construct, easy to install, operate, maintain and repair, and rugged and durable in use.

Other objects and advantages of the present invention will become apparent from a consideration of the following description, taken in connection with the accompanying drawings, in which:

FIG. 1 is a view taken on the line 1--1 of FIG. 2, showing structure for discharging separated material from centrifugal drums of centrifugal separators according to the prior art;

FIG. 2 is a cross-sectional view taken on the line 2--2 of FIG. l;

FIG. 3 is a first embodiment of apparatus according to the present invention, taken on the line 3--3 of FIG. 4;

FIG. 4 is a view taken on the line 4--4 of FIG. 3;

FIG. 5 is a view similar to FIG. 1 but taken on the line 5--5 of FIG. 6 and showing another embodiment of apparatus according to the present invention;

FIG. 6 is a view taken on the line 6--6 of FIG. 5;

FIG. 7 and 8 are views similar to FIGS. 5 and 6, respectively, but showing another embodiment of apparatus according to the present invention;

FIGS. 9 and 10 are views similar to FIGS. 7 and 8, respectively, but showing still another embodiment of the present invention;

FIG. 11 is a fragmentary bottom plan view of a portion of FIG. 10;

FIGS. 12 and 13 are views similar to FIGS. 3 and 4, but showing still another embodiment of the invention;

FIGS. 14, 15 and 16 are top plan and cross-sectional views of a portion of the structure of the embodiment of FIGS. 12 and 13,

FIGS. 15 and 16 being taken on the lines 15--15 and 16--16, respectively, of FIG. 14;

FIG. 17 is an elevational view of a float element for use in the embodiment of FIGS. 12-16;

FIG. 18 is a view taken on the line 18--18 of FIG. 19;

FIG. 19 is a view taken on the line 19--19 of FIG. 18;

FIG. 20 is a perspective view of a float element for use in the embodiment of FIGS. 18 and 19;

FIG. 21 is a view similar to FIG. 18 but showing still another embodiment of the invention;

FIG. 22 is a cross-sectional view taken on the line 22--22 of FIG. 21; and

FIG. 23 is a perspective view of the float element of the embodiment of FIGS. 21 and 22.

Referring now to the drawings in greater detail, and first with respect to the prior art illustrated in FIGS. 1 and 2, there is shown a centrifugal drum for a centrifugal separator, having a closing cover 1 having on its underside a circular recess 2 from which extends the discharge conduit 3 for the lighter liquid and that terminates in an outlet 4, the lighter liquid having entered the conduit 3 through opening 5. A discharge conduit 6 for the heavier liquid terminates in an outlet 7 and receives heavier liquid from the opening 8 which is substantially radially farther outward than the opening 5. The outlets 4 and 7 lie on a common circular line 9, and hence are equal radial distances from the axis of rotation.

The drum is completed by a cylindrical wall 10 and contains a centrally disposed feed pipe 11. A separating bottom 12 is traversed by openings 13 and 14 and divides the interior of the drum into a separating chamber 15 containing the separated materials, and a further chamber 16. The broken line 17 illustrates one position of the boundary surface between the separated components, there being a zone of mixed material whose boundaries are indicated at 18. For a somewhat different ratio of the components, characterized by less heavy material and more lighter material, the interface between the separated components is indicated at 19, with the boundaries of the zone of mixture indicated at 20. Obviously, however, if the proportions of the mixture fluctuate so that the lines 17 or 19 are more drastically displaced from their illustrated positions, then an unintended component will be discharged through the outlet 4 or 7.

A first embodiment of apparatus according to the present invention is shown in FIGS. 3 and 4. In this embodiment, use is made of the fact that the centrifugal force exerted by the material on the container wall varies as the density of the total mixture. Thus, when there is an increased proportion of heavier material, the centrifugal force is greater; but when there is an increased proportion of lighter material, then the centrifugal force is less.

In the embodiment of FIGS. 3 and 4, there is provided a control disc 21 rotatably mounted on the underside of the cover and having setting slots 22 which are adapted selectively to position the flow grooves 23 of the disc into register with the corresponding discharge openings 5 and 8 for separated materials. Depending on the setting of the control disc and the position of the flow grooves, the discharge outlets for separated material are closed, throttled or opened.

Apparatus for rotating the disc 21 according to the proportion of the components relative to each other is provided in the form of a corrugated sleeve diaphragm 40 which is a pressure-responsive element. Sleeve 40 is closed at one end by a pressure plate 41 that carries a pressure pin 42 that transmits the movements of plate 41 to a pivotally mounted lever 43 that carries at its outer end a pin 44 that enters and slides in the slot 22. Lever 43 is pivotally mounted to the cover at 45 and carries a weight adjustable lengthwise of the lever to balance the centrifugal force of the arm. Preferably, disc 21 is circular so as to avoid changes in its centrifugal force.

In operation, changes in pressure on the sleeve 40 and plate 41, resulting from changes in the centrifugal force exerted by a mixture the proportion of whose components changes, will swing the lever 43 to turn the disc 21 so that the flow grooves 23 will open or close or throttle their respective outlets thereby to prevent discharge of the wrong component from a given outlet.

The embodiment of FIGS. 3 and 4 operates by variation of centrifugal force, directly mechanically to regulate the discharge of the components. Instead, the transmission can be performed electrically. Thus, at the left-hand side of FIGS. 5 and 6, there is shown an electrical device according to the present invention, in which the variation of centrifugal pressure moves the plate 41 inwardly until the pin 42' which is carried thereby reaches electrical contacts 47. A pair of casings 48 and 49 are mounted on the outer side of the cover for housing electrical apparatus that is interconnected between the two casings by means of an electrical conduit 50. Batteries 51 and servomotors 52 are housed in the casings. The servomotor 52 rotates a shaft 54 through gearing 55, 56 to rotate the disc 21 when one or more of the contacts 47 is closed.

It is also not necessary to rely on variations in centrifugal force according to the variations in mixture proportions. It is also possible to rely on the actual position of the interface between the two liquids. This position can be sensed electrically if one of the liquids is conductive and the other is not. Such an arrangement is indicated at the right of FIGS. 5 and 6, in which the conductive component in the chamber 16 selectively contacts at least a pair of the contacts 39a, 39b, 39c, and 39d, thereby completing a circuit through the amplifier 53 which amplifies the switching current to a value required for switching one of the power units to rotate the disc 21. These power units can also include electromagnets 57, and it will be understood that the operation of the embodiments shown at the left and right of FIGS. 5 and 6 can be alternative or additive as desired.

FIGS. 7 and 8 show another embodiment of apparatus for rotating the disc 21, in which the magnets 57, 57a are selectively actuable to swing the lever 58 in one direction or the other, thereby directly to turn the disc 21.

In FIGS. 9-11, the disc 21 is replaced by a slide member 24 actuated by a rocking lever 59 whose upper end is selectively attracted to one of the magnets 57 and 57a, thereby to open or close or throttle the openings 5 and 8.

In FIGS. 12-17 is shown another embodiment of the present invention, in which the position of a float directly mechanically opens or closes or throttles the outlet openings. The float functions much like a hydrometer, whose position is constant with respect to the interface no matter where the interface is located, as the specific density of the float is intermediate the specific densities of the liquid components. The float is thus at equilibrium with respect to the interface not only when the liquids are stationary, but also when they are rotating rapidly, so that there is no tendency for such a float to wander from the interface despite variations in the speed of rotation of the drum.

In FIGS. 12-17, a float 25 is employed as the setting member whose position varies as the position of the interface between the separated components. Float 25 has axial stubs 26 thereon that joint the main float body in inclined sealing shoulders 27. Float 25 is thus axially reciprocable in guide members 32, 33 (FIGS. 14-16) the radially inner guide member 32 providing an outlet for the lighter component and the radially outer guide member 33 providing an outlet for the heavier component. To this end, each of the members 32 and 33, which are mounted on the underside of the cover, has intake openings 34 that communicate with channels 35 with a seat 36 that provides a sliding support for one of the stubs 26. On the other side of the seat 36, a channel 37 communicates through an outlet 38 with the respective outlet opening 5 or 8 in the underside of the cover. In operation, it will be evident that changes in the position of the interface cause the float 25 to open or close or throttle the outlets correspondingly.

In the embodiment of FIGS. 12-17, the float and the valve means for the outlets are thus integral with each other.

In the embodiment of FIGS. 18, 19 and 20, the disc 21 is again provided, which is turned by the position of a float 25' that has an axial bore 28 therethrough and which carries a radially extending pin 29 that projects outwardly from its upper surface as seen in FIGS. 18 and 20. A radially extending shaft 31, fixed to the cover, provides a mounting on which float 25' slides radially with changes in the position of the interface between the liquids. The pin 29 registers in a slot 22' in disc 21 thereby to turn the disc 21 upon changes in the position of the interface.

In the embodiment of FIGS. 21-23, the float itself serves as the regulatory valve, as also in FIGS. 12 and 13. Thus, when a float 25"is mounted and moves as in FIGS. 18 and 19, but has a flat upper surface 30 which directly slides over the openings 5 and 8 to open or close or throttle them according to the position of the interface with which float 25"moves.

In view of the foregoing disclosure, therefore, it will be evident that all of the initially recited objects of the invention have been achieved.

Although the present invention has been described and illustrated in connection with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit of the invention, as those skilled in this art will readily understand. Such modifications and variations are considered to be within the purview and scope of the present invention as defined by the appended claims.

Claims

Having described my invention, I claim:

1. Apparatus for controlling the discharge of separated liquids from centrifugal separators, comprising a centrifugal drum having radially spaced outlets for separated liquid components, valve means for controlling the flow of separated components through both of said outlets, and means responsive to a change in proportion of the components relative to each other to actuate said valve means.

2. Apparatus as claimed in claim 1, said responsive means comprising means responsive to a change in the centrifugal force exerted by the components.

3. Apparatus as claimed in claim 2, said responsive means comprising means defining a chamber having a sidewall whose position varies with variations in the centrifugal force exerted by the components, and means responsive to changes in position of said sidewall to actuate said valve means.

4. Apparatus as claimed in claim 3, said means responsive to changes in position of said sidewall comprising a lever system interconnected with said valve means.

5. Apparatus as claimed in claim 3, said means responsive to changes in position of said sidewall comprising electrical switch means for controlling said valve means.

6. Apparatus as claimed in claim 1, said responsive means comprising means responsive to the position of the interface between the separated components.

7. Apparatus as claimed in claim 6, said responsive means comprising a series of radially spaced electrical contacts to be bridged by an electrically conductive separated component.

8. Apparatus as claimed in claim 1, said responsive means comprising a float whose position varies with the position of the interface between the separated components.

9. Apparatus as claimed in claim 8, said float and valve means being integral with each other.

10. Apparatus as claimed in claim 1, said valve means being common to both of said radially spaced outlets and being movable in one direction to open one of said outlets and to close the other of said outlets, and being movable in another direction to close said one outlet and to open said other outlet.