US2993580A - Centrifugal separators - Google Patents

Description

July 25, 1961 F. O'CONOR ETAL 2,993,580

CENTRIFUGAL SEPARATORS Filed Oct. 9, 1957 2 Sheets-Sheet 1 INVENTORS. FRANK O'CONOR FIG. I

w Amwggm AT ORNEY July 25, 196 F. o'coNoR ET AL 2,993,580

CENTRIFUGAL SEPARATORS Filed Oct. 9, 1957 2 Sheets-Sheet 2 FIG. 3

INVENTORS. FRANK O'CONOR y EDWARD A.DAUBMAN A TORNEY.

Patented July 25, 1961 2,993,580 CENTRIFUGAL SEPARATORS Frank OConor, Moline, and Edward A. Daubman, East Moline, 111., assignors to American Machine & Metals, Inc., East Moline, 11]., a corporation of Delaware Filed Oct. 9, 1957, Ser. No. 689,090 Claims. (Cl. 192-136) The present invention relates to centrifugal separators, and particularly to a new and improved cover interlock mechanism that will prevent access to the interior of the separator While the same is operating.

A principal object of this invention is to provide a cover interlocking mechanism, effective during the accelerating and decelerating of the rotatable basket of a centrifugal separator that is driven and braked by hydraulic components in a closed hydraulic circuit.

Another object of the invention is to provide a cover interlock mechanism for a centrifugal separator that will require manual re-starting of the main motor each time the cover is opened.

One aspect of the invention may be to provide a centrifugal separator with a closed circuit hydraulic system embodying an hydraulic pump that is driven by an electric motor and wherein the hydraulic pump supplies liquid under pressure in a closed circuit to an hydraulic motor that is belted or otherwise drivingly connected to the rotatable basket of the separator. A hinged cover plate may provide access to the interior of the separator and a limit switch may be provided that is connected in series with the electric motor that drives the hydraulic pump. The hydraulic pump may be of the variable capacity, positive displacement type that can act as a brake for decelerating the rotatable basket of the separator. An hydraulically actuated piston and cylinder mechanism may be provided for locking the cover plate during the accelerating and decelerating periods of activity of the separator. This piston and cylinder mechanism may be supplied on its one end with pressure liquid through a parallel line arrangement from both sides of the closed circuit for the hydraulic pump and motor; and, on its other end with constant pressure liquid from a separate source such, for example, as from a super charger forming part of the hydraulic pump.

Suitable check valves may be provided in the parallel line arrangement leading to the one end of the piston and cylinder mechanism so that when one of the parallel lines is elfective to actuate the hydraulic piston mechanism, the pressure liquid will now flow into the other parallel line, and vice versa.

The above, other objects and novel features of the invention will become apparent from the following specification and accompanying drawings which are merely exemplary.

In the drawings:

FIGURE 1 is an elevational view of a centrifugal separator to which the principles of the invention have been applied;

FIG. 2 is a top plan view of the separator shown in FIG. 1; and

FIG. 3 is a schematic wiring diagram and hydraulic circuit of certain components of the invention.

Referring to the drawings, and particularly to FIGS. 1 and 2, the principles of the invention are shown as applied to a centrifugal separator of the bottom discharge type, although they may with equal facility be applied to any type of centrifugal separator. The separator shown may include a bedplate 10 on which are mounted three equally spaced pedestals 11 that include mechanism for supporting a housing 12 for limited oscillatable movement. The housing 12 may have fixed to its sides, brackets 13 that extend into the pedestals 11 to cooperate with supporting mechanism therein.

A basket may be located within the housing 12 and may comprise a perforated cylindrical member 14 for passing liquid therethrough, which liquid is collected within an annular chamber within the housing 12. The bottom of the basket 14 may be provided with discharge passages for gravitating solids therein out through the bottom of the housing 12.

The basket 14 may be provided with a multiple V- belt sheave (not shown) on its vertical axis of revolution that is in driving engagement with V-belts 15. The belts 15 also engage another similar sheave (not shown) on the axis of rotation of an hydraulic motor 16. The motor 16 is of the constant displacement type and includes ports 17 and 18. The ports 17 and 18 are connected to ports 19 and 20, respectively, of a variable volume positive displacement hydraulic pump 21 by lines 22 and 23, forming a closed hydraulic circuit. The hydraulic pump 21 by means of a lever control 21' may be adjusted to deliver from zero to maximum volume of liquid to the hydraulic motor 16 and in addition may include a super charging gear pump built into thehousing of the pump 21, and adapted to deliver liquid under a predetermined substantially constant pressure through a line 24 for operating various components of the separator. An electric motor 25 may be provided for driving the pump 21 at a constant speed.

From the foregoing, it is evident that adjusting the displacement of the pump 21 will cause different rates of rotation of the basket 14. The speed of the motor 16 during the unloading operation is 50 rpm. The capacity of pump 21 may be adjusted to cause the motor 16 to rotate basket 14 at a loading speed that is substantially faster than the unloading speed; and, the pump 21 may be adjusted to cause the motor 16 to rotate basket 14 at an extracting speed that is very much faster than the unloading speed. Since the electric motor 25 rotates at a constant speed and the pump 21 cannot be reversely driven, sudden adjustment of pump 21 from an extracting speed to any lower speed will cause the motor 16 to act as a pump tending to drive the pump 21 as a motor. However, since pump 21 cannot be driven by the motor 16 acting as a pump, a braking action on the rotation of basket 14 is provided.

The structure thus far described is substantially the same as that shown and described in application Serial Number 657,801 filed May 8, 1957, in the names of Frank OConor et al., to which application attention is directed for details not specifically described herein.

The top of the housing 12 is adapted to be covered by a top plate 26 and, a cover plate 27 of semicircular form mounted on a hinge pin 27 may cover a correspondingly shaped opening in the top plate 26 to provide access to the interior of the basket 14. A normallyclosed limit switch 28 adapted to be operated by a cam 28' on the cover hinge pin 27' may be arranged so that it opens when the cover plate 27 is opened, thus preventing the starting of motor 25 when cover plate 27 is open. The circuitry for the limit switch 28 will be described later.

In order to prevent opening of the cover plate 27 when the basket 14 is rotating, an hydraulic interlock is provided. It may comprise a cylinder 29 mounted on the top plate 26 of the housing 12 and may include a piston 30 having a rod 31 (FIGS. 1 and 3) extending outwardly from one end of the cylinder 29. Aport 32 of the cylinder 29 may be connected by a line 33 to the line 24 that is supplied with liquid under substantially constant pressure at about p.s.i. from the built-in supercharging gear pump within pump 21. The other port 34 of cylinder 29 may be connected by parallel lines 35 and 36 to lines 22 and 23, respectively.

Referring to FIG. 3, the line 36 includes a check valve 37 permitting liquid flow fromline 23 to port 34 but preventing flow in the opposite direction. Line 35 includes a check valve 38 that permits liquid flow from line 22 to port 34 but prevents flow in the opposite direction. A needle valve 39 is provided in a line 40 leading from lines 36, 35 and port 34 to a sump 41.

With the apparatus in the condition as shown in FIG. 3, closing start push-button switch 42 energizes relay coil 43 which closes switches 44 in lines L L and L thereby energizing motor 25, and closes a normally open holding switch 45, to hold the circuit for relay coil 43 when switch 42 is released.

Energization of the motor causes rotation of the pump 21. With pump 21 set for zero delivery, the pressure in line 36 will be less than 145 psi. The super charging gear pump within pump 21 causes pressure liquid to flow through lines 24 and 33 to port 32 at approximately 175 p.s.i., forcing piston leftwardly (FIG. 3) so that rod 31 is retracted from cover plate 27. Accordingly, at zero speed of rotation of basket 14, the cover plate 27 may be opened at will, however, so opening it opens cover limit switch 28, thereby de-energizing relay coil 43, thus causing de-energization of motor 25.

During an operating cycle, adjustment of pump 21 to deliver liquid to motor 16 at a rate to rotate basket 14 at a loading, extracting, or unloading speed causes a pressure build-up to occur within lines 36 and 49 that is far in excess of that in lines 24 and 33, and which may reach a maximum of 1,600 p.s.i., thereby forcing piston 30 rightwardly so that rod 31 extends over cover plate 27 and efiectively prevents its being opened. The check valve 38 prevents this pressure liquid from entering line 35, and the needle valve 39 is set to prevent any substantial loss of this pressure liquid to sump 41.

With the basket rotating, adjustment of pump 21 to reduce supply liquid to motor 16 causes braking to occur. Thus this change decreases the supply of pressure liquid to line 23, but builds up a pressure in lines and far in excess of that of the constant pressure in lines 24 and 33, and which pressure may reach a maximum of 1,600 p.s.i., whereupon piston 30 is held in its rightward position with rod 31 over cover plate 27 The check valve 37 prevents this pressure liquid from enter ing line 23. 7

When the pressure in line 40 falls below a predetermined value of, say, about 145 p.s.i., the constant pressure of about 175 p.s.i. in lines 24 and 33 forces piston 30 and its rod 31 leftwardly, and the liquid on the left side of piston 30 exhausts past the needle valve 39 to the sump 41.

From the foregoing it is evident that a simple hydraulic interlock has been provided that will mechanically prevent access to the interior of a centrifugal separator during rotation of the basket While permitting access to said interior when the basket is stationary.

Although the various features of the new and improved cover interlock for centrifugal separators have been shown and described in detail to fully disclose one embodiment of the invention, it will be evident that numerous changes may be made in such details, and certain features may be used without others without depart ing from the principles of the invention.

What is claimed is:

1. In a centrifugal separator having a substantially stationary housing within which a rotatable basket is mounted, a closed circuit including an hydraulic pump and motor means for rotating said basket at a plurality of different speeds; means for adjusting said pump and motor means to vary the speed at which said basket is rotated; a cover plate adapted to provide access to the interior of said separator; and interlocking means ineluding means responsive to the pressures developed on each side of the hydraulic pump and motor means for preventing the opening of said cover plate when said pump and motor means is effective to rotate said basket, as well as during periods of acceleration and deceleration; and means for exerting a substantially constant force in opposition to said pressure responsive means.

2. In a centrifugal separator having a substantially stationary housing within which a rotatable basket is mounted, a closed hydraulic circuit including an hydraulic pump and motor means for rotating as well as stopping the rotation of said basket; an electric motor for operating said pump and motor means; a cover plate adapted to provide accms to the interior of said separator; means associated with said cover plate for preventing the energizing of said electric motor when said cover plate is open; and interlocking means including means responsive to the pressures developed on each side of the hydraulic pump and motor means for preventing the opening of said cover plate when said pump and motor means is effective to rotate said basket, as well as during periods of acceleration and deceleration.

3. In a centrifugal separator having a substantially stationary housing within which a rotatable basket is mounted, a closed circuit including an hydraulic pump and motor means for rotating said basket at a plurality of different speeds; means for adjusting said pump and motor means to vary the speed at which said basket is rotated; acover plate adapted to provide access to the interior of said separator; and interlocking means including means responsive to the pressures developed on each side of the hydraulic pump and motor means for preventing the opening of said cover plate when said pump and motor means is eifective to rotate said basket,

as well as during periods of acceleration and deceleration.

4. In a centrifugal separator having a substantially stationary housing within which a rotatable basket is mounted, a closed circuit including an hydraulic pump and motor means for rotating said basket at a plurality of different speeds; means for adjusting said pump and motor means to vary the speed at which said basket is rotated; a cover plate adapted to provide access to the interior of said separator; interlocking means including means responsive to the pressures developed on each side of the hydraulic pump and motor means for preventing the opening of said cover plate; means for rendering said interlocking means ineflFective when said adjusting means has been operated to cause said pump and motor means to stop the rotation of said basket; and means for rendering said interlocking means efiective when said adjusting means is operated to cause said pump and motor means to rotate said basket.

5. In a centrifugal separator having a substantially stationary housing within which a rotatable basket is mounted, a closed circuit including an hydraulic pump and motor means for rotating said basket at a plurality of difierent speeds; means for adjusting said pump and motor means to vary the speed at which said basket is rotated; a cover plate adapted to provide access to the interior of said separator; an interlocking element; a piston and cylinder device mounted on the top of said housing and adapted to cause said interlocking element to be moved into and out of interlocking relation with said cover plate; means for connecting both sides of said hydraulic pump and motor means to the one end of said cylinder and piston means; and means for connecting a source of fluid at substantially a constant pressure to the other side of said piston and cylinder means.

6. In a centrifugal separator having a substantially stationary housing within which a rotatable basket is mounted, a closed circuit including an hydraulic pump and motor means for rotating said basket at a plurality of different speeds; means for adjusting said pump and motor means to vary the speed at which said basket is rotated; a cover plate adapted to provide access to the interior of said separator; an interlocking element; a piston and cylinder device mounted on the top of said housing and adapted to cause said interlocking element to be moved into and out of interlocking relation with said cover plate; means for connecting both sides of said hydraulic pump and motor means to the one end of said cylinder and piston means; means for connecting a source of fluid at substantially a constant pressure to the other side of said piston and cylinder means; and a check valve connected to each side of said pump and motor means and arranged to pass high pressure fluid away from the pump and motor means and to prevent the passage of high pressure fluid toward said pump and motor means.

7. In a centrifugal separator having a substantially stationary housing within which a rotatable basket is mounted, a closed circuit including an hydraulic pump and motor means for rotating said basket at a plurality of different speeds; means for adjusting said pump and motor means to vary the speed at which said basket is rotated; a cover plate adapted to provide access to the interior of said separator; an interlocking element; a piston and cylinder device mounted on the top of said housing and adapted to cause said interlocking element to be moved into and out of interlocking relation with said cover plate; means for connecting both sides of said hydraulic pump and motor means to the one end of said cylinder and piston means; means for connecting a source of fluid at substantially a constant pressure to the other side of said piston and cylinder means; a check valve connected to each side of said pump and motor means and arranged to pass high pressure fluid away from the pump and motor means and to prevent the passage of high pressure fluid toward said pump and motor means; and an adjustable needle valve within a line leading to a sump from the end of said piston and cylinder means to which both sides of said pump and motor means are connected.

8. In a centrifugal separator having a substantially stationary housing within which a rotatable basket is mounted, a closed hydraulic circuit including an hydraulic pump and motor means for rotating as well as stopping the rotation of said basket; an electric motor for operating said pump and motor means; a cover plate adapted to provide access to the interior of said separator; switch means Within the circuit for said electric motor for preventing its energizafion when said cover plate is open; and interlocking means responsive to the pressure developed on each side of the hydraulic pump and motor means for preventing the opening of said cover plate when said pump and motor means is eflective to rotate said basket, as well as during periods of acceleration and deceleration.

9. In a centrifugal separator having a substantially stationary housing within which a rotatable basket is mounted, a closed hydraulic circuit including an hydraulic pump and motor means for rotating as Well as stopping the rotation of said basket; an electric motor for operating said pump and motor means; a cover plate adapted to provide access to the interior of said separator; switch means within the circuit for said electric motor for de-energizing said electric motor when said cover plate is opened; an interlocking element; a piston and cylinder device mounted on the top of said housing and adapted to cause said interlocking element to be moved into and out of interlocking relation with said cover plate; means for connecting both sides of said hydraulic pump and motor means to the one end of said piston and cylinder means; and means for connecting a source of fluid at substantially a constant pressure to the other side of said piston and cylinder means.

10. In a centrifugal separator having a substantially stationary housing within which a rotatable basket is mounted, a closed hydraulic circuit including an hydraulic pump and motor means for rotating as well as stopping the rotation of said basket; an electric motor for operating said pump and motor means; a cover plate adapted to provide access to the interior of said separator; switch means Within the circuit for said electric motor for deenergizing said electric motor when said cover plate is opened; an interlocking element; a piston and cylinder device mounted on the top of said housing and adapted to cause said interlocking element to be moved into and out of interlocking relation with said cover plate; means for connecting both sides of said hydraulic pump and motor means to the one end of said piston and cylinder means; means for connecting a source of fluid at substantially a constant pressure to the other side of said piston and cylinder means; a check valve connected to each side of said pump and motor means and arranged to pass high pressure fluid away from the pump and motor means and to prevent the passage of high pressure fluid toward said pump and motor means; and an adjustable needle valve within a line leading to a sump from the end of said piston and cylinder means to which both sides of said pump and motor means are connected.

References Cited in the file of this patent UNITED STATES PATENTS 1,111,001 Bartholomew et a1 Sept. 22, 1914 1,501,642 Benjamin July 15, 1924 2,004,064 Jordan June 4, 1935 2,592,596 Pengelly Apr. 15, 1952 2,821,840 Hays Feb. 4, 1958 FOREIGN PATENTS 246,563 Germany Mar. 24, 1909 336,851 Germany May 13, 1921 567,515 Great Britain Feb. 16, 1945 942,919 Germany May 9, 1956 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Eatent No. 2,993,580 July 25 1961 Frank 0*Conor et a1.

or appears in :bhe above numbered pat- It is hereby certified 'bhab err e said Letters Patent should read as entrequiring correction and that th correcbed below.

Column l, line 49 for "now" read not (SEAL) Attest:

ERNEST W. SWIDER Attesting Officer DAVID L. LADD Commissioner of Patents

Images