US2694494A - Centrifugal basket valve mechanism - Google Patents

Description

7 Nov. 16, 1954 J. HERTRICH 2,694,494

I CENTRIFUGAL BASKET VALVE MECHANISM Filed July 15, 1950 VB VLSV L2. no

INVEN TOR.

FIG 3 CENTRIFUGAL BASKET VALVE MECHANISM Joseph Hertrich, Hamilton, Ohio, assignor to The Western States Machine Company, Hamilton, Ohio, a corporation of Utah Application July 15, 1950, Serial No. 173,990

7 Claims. (Cl. 210-74) This invention relates to a new and useful basket bottom valve system for heavy cyclical centrifugal machines of the type used for separating liquid from solids in large scale industrial processes such as, for example, the manufacture, refining or drying of sugar, dextrose or other crystalline or granular materials. This application is a continuation-in-part of my copending application Serial No.199,04O, now Patent Number 2,667,974, filed June 14, 949.

Centrifugals of that type generally employ a large rotary basket formed with an opening in the bottom through which solids centrifugally separated in each operating cycle may be removed by operation of a mechanical discharger as the basket is rotated slowly to force its contents against the discharger shoe. During the running period of each cycle the bottom opening is closed by a cover or valve member which commonly has the form of an annular plate, and which must be removed at the end of that period in order toexpose the opening so that the treated solids may be discharged. The valve member generally is removed by hand and disposed in a position near the top of the basket Where it will not obstruct either the discharger operation or the escape of discharged solids or the action of a sprayer when the sprayer is operated to clean screens on the basket side wall.

The usual manipulations of the basket valve member, by the attendant of the machine, are time-consuming and involve objectionable burdens and hazards. Practical means for opening and closing the basket bottom mechanically have long been needed for those reasons, and for the further important reason that such means are required in order to provide a satisfactory automatically discharged cyclical centrifugal machine. The problem. however, has not been simple, due to limitations of available space and the importance of avoiding bulky or complex mechanisms, of which several examples exist in the efforts of prior workers in the art.

The principal object this invention is to provide a basket bottom valve system which fulfills the needs above indicated.

Another object of the invention is to provide a combination of a basket bottom valve and a valve lifting and lowering device, of such simple, compact and efiicient construction that the principal elements can be arranged inside the centrifugal basket without occupying needed space on or above its casing and without obstructing the discharger action, the sprayer action or any of the other elements or functions of the machine.

Another object is to provide a combination by which the exposure of the basket bottom opening to provide passageway for discharged solids, or the replacement of a valve member to normal closed position, can be effected very quickly and with a minimum of motion in the valve operating device.

Still another object is to provide such a combination in which the valve operating device normally is disengaged from the valve member so that the latter can spin freely with the centrifugal basket without being worn or obstructed by the operating device.

A further object is to provide a valve operating device or mechanism which is held permanently inside the centrifugal basket and yet is so constructed and arranged that it will not be fouled by steam, liquids, solids or other substances present within the basket during operations of the centrifugal.

According to this invention, the basket bottom opening which forms an outlet for discharged solids is normally States Patent F covered by a movable valve member of tapered or frust0- conical form which rests in the path of movement of a valve operating device extending inside the basket, andthe operating device includes a member swingable within the basket from a normal position at which it is disengaged from the valve through a path in which it first engages the valve and then lifts and tilts the valve into an open position where it hangs tilted toward a side of the bottom opening away from the zone of discharging action. The form and coaction of the elements are such that in this tilted position the valve cannot obstruct the operation of the discharger or the rotation or discharging of solids in the basket or the operation of the usual sprayer to clean the basket screens. The valve operating device is of simple construction. It can be operated efliciently by fluid-pressure means, and its operation can be controlled either manually or by automatic control elements coordinated with elements automatically controlling other functions of the centrifugal.

Other objects, features and advantages of the invention will appear from the following detailed description and the accompanying drawings of an illustrative embodiment thereof.

In the drawings:

Figure l is an elevation, partially in vertical cross section and with some parts broken away, of an assembled basket valve and valve operating device embodying this invention, the valve appearing in open position;

Figure 2 is a partial elevation and partial vertical cross section similar to that shown in Figure 1, with the basket valve in its'normal closed position on the basket bottom;

Figure 3 is a fragmentary plan view of the same assembly with the lifting arm in position to start raising the basket valve; and

Figure 4 is a partial elevation and partial vertical I cross section of the same assembly viewed parallel to the plane of movement of the lifting arm, showing the lifting arm in idle position and also in a broken line position which it occupies when the basket valve has been opened. The broken line or raised position of the basket valve is schematic only, since the valve actually turns angularly about the free end of the arm while being lifted and tilted thereby.

The drawings illustrate in full and broken lines several related elements of a heavy centrifugal machine embody- The centrifugal includes a basket 1 having a perforated side wall 2, a cap 3, and a bottom 4 carried by the lower end of a vertical driving shaft or spindle 5. The spindle 5 is suspended in a gyratory manner from a suitable overhead support (not shown) and is connected to a suitable prime mover (not shown) for effecting rotation of the basket. The basket bottom 4 is formed with an opening 4a around the spindle S to provide a solids outlet, while basket cap 3 has a central opening 3a affording access to the interior of the basket. The

' basket 1 is surrounded by a stationary casing or curb 14 having a centrally open top 15 which provides support for a discharger mechanism of which only the shoe 20 and shoe shaft 21 are shown. The casing top also supports a conventional sprayer 18 and the valve operating a device 17 of a basket bottom valve system embodying this invention.

The basket bottom valve according to this invention is formed as a frusto-conical member 12 which surrounds the basket spindle 5 and has a diameter at its base sufiicient to close the outlet opening 4a in the basket bottom. A cylindrical collar 12b on the upper or small end of member 12 carries an outwardly and downwardly extending annular flange which forms beneath itself a downwardly opening annular channel or recess 121, for

. a purpose to be described. The lower end portion of spindle 5 is formed with a cylindrical enlargement 5a which fits inside collar 12b so as to keep the valve member in proper place when the latter is seated in its normal position closing outlet 4a (Figs. 2 and 4). An inwardly 1 tapered or frusto-conical spindle portion 5b extends upwardly from the cylindrical portion 5a to merge into the normal diameter of the spindle, the tapered portion being immediately above collar 12b when the valve is seated.

Opening and closing of the basket bottom opening 4a are accomplished by means of a valve operating device 17 which is held permanently inside the basket and, when actuated, moves to engage the valve member 12 and then to lift and tilt it to a position where it exposes opening 4a on the side of the discharger action but does not obstruct any of the normal functions or elements of the centrifugal machine.

The valve operating device includes a fluid pressure cylinder 134 having its base plate 129 mounted on an inwardly extending portion a of the curb top. A vertically movable plunger 133 in the cylinder extends downward into a housing tube 128 which extends from the curb top to an open lower end within the confines of the basket. To that end is fixed a laterally and downwardly directed lug 125 which carries a pivot or fulcrum pin 124 in a position below and laterally offset from the open end of tube 128.

A lifting arm 123, constituting the principal working element of the valve operating device, is formed at one end with bifurcations 126 and 127 which straddle lug 125 and are pivotally mounted on the fulcrum pin 124. Thus the arm 123 is swingable on pin 124 in a vertical plane. Its body extending away from the bifurcated portion normally hangs downwardly from pin 124 and is formed to swing in a path clearing the conical body of the valve 12 when the valve is in normal or closed position. At its free end arm 123 is formed with a forwardly protruding tip 122:! carried by a lateral extension 122 from the body of the arm. The path of tip 122a during swinging movement of the arm is intersected by the outward extension or flange 120 of collar 12b, so that in upward movement tip 122a engages from below into the channel 121.

The bifurcations 126 and 127 extend beyond the fulcrum pin at an angle to the body of arm 123, so as to terminate at a point below the open end of tube 128 where a pin 130 joins them pivotally to the lower end of a connecting rod 131 which, in turn, extends upwardly through tube 128 to a pivotal connection at 132 with the air cylinder plunger 133.

Air lines 135 and 136 lead into the upper and lower ends, respectively, of the air cylinder 134, from a fourway solenoid valve VLSV, of conventional construction, through which the lifting and lowering movements of the basket bottom valve are controlled. The solenoid valve may be located at any desired position and is connected with a compressed air supply line 110 from which air under pressure is delivered into the lower side of the cylinder when VLSV is deenergized, line 135 then being vented to the atmosphere, while the air pressure enters the upper side of the cylinder and line 136 is vented to the atmosphere when VLSV is energized. The condition of the solenoid valve, hence the position of the basket bottom valve 12, is controlled by an electrical cir-.

cuit including a normally open switch VB in one of two power lines L1 and L2 which connect with the actuating coil of VLSV. Switch VB may be either a manually operated push button or a contact member of a timer or other automatic control device used to control other phases of the centrifugal operations, depending upon whether manual or automatic control of the basket bottom valve operations is desired.

When solenoid valve VLSV is deenergized, the plunger 133 is in raised position and the lifting arm 123 extends downward from the pin 124 (Fig. 2 and 4) and is disengaged from the bottom valve 12. Valve 12 then is free to spin with the basket, without restraint, and may even be removed manually from opening 4a if desired. In this normal position of the mechanism, tube 128 shields most of rod 131 and its pivotal connection with plunger 133 from liquids, gases or solids inside the basket, and plunger 133 is almost entirely contained within the cylinder 134. See Figure 4.

Whenever the bottom opening of basket 1 is to be exposed, usually after the centrifugal has been decelerated to conclude the treatment of a charge in the basket, it is necessary only that switch VB be closed to energize VLSV. Air pressure then enters the upper end of cylinder 134 and moves plunger 133, connecting rod 131 and the bifurcated end of arm 123 downward so as to swing arm 123 through a vertical plane, about the axis at 124, from its normal position to a working or raised position shown in Figure l and by broken lines in Figure 4. As the arm so swings, the lateral projection 122a on its free end engages in channel 121 under flange 120 and then lifts and tilts the frusto-conical valve 12 to open or raised position.

The path of swinging movement of arm end 122 extends to a side of the basket spindle 5 away from the zone of action of the discharger shoe 20 and shoe shaft 21, and the arm end engages beneath valve flange 120 on a corresponding side of its axis and center of gravity. It results that the bottom valve 12 not only is lifted by the arm but at the same time undergoes a tilting and swinging motion with respect to the axis of the basket. This eventuates into an open position for valve 12, as illustrated in Figure 1, where'it continues to be largely within the lower region of the basket, but where it does not obstruct discharging or spraying functions and has little or no frictional contact with the basket spindle.

When solenoid valve VLSV is deenergized to shift pressure from the upper to the lower end of cylinder 134, the arm 123 is drawn back to its normal position where it hangs below curb top portion 15a, and the cone valve, falling under its own weight, is guided back to its normal closed position by the conical taper 5b and settles in place with collar 12b closely surrounding enlargement 5a of the spindle. The clearance between the collar 12b and spindle portion 5a is such that the valve is slidable vertically on the latter but cannot tilt or wobble out of place while the basket is spinning.

If desired, arm 123 or its operating mechanism can be formed so that the free end of the arm or an attachment to the arm will lie directly over a part of the valve 12 with only a small clearance in the normal or idle position of the apparatus. Thus the bottom valve can be assured of having become seated evenly, e. g. of not being cocked out of place by adhering solids or the like, before the basket is allowed to spin to high speed.

Furthermore, in order to allow for variations in the position of the basket axis and to permit easy re-engagement of arm 123 below flange 120 if it should become accidentally displaced above the flange, the supporting base 129 for the valve lifting mechanism can be made resilient by forming it of rubber or the like, so that the whole mechanism may swing laterally a limited distance under an abnormal force transverse to the path of the arm. If the arm becomes displaced above flange 120, its free end may then be returned to normal position, without having to dismantle the apparatus, by simply causing the air cylinder to force the end 122 downward over the downturned outer surface of the flange; tube 128 and cylinder 134 then swinging sidewise to the extent necessary on the resilient support. To assist this action the lateral end 122 may be made with a curved or cam shape on the under side.

It is to be understood that the detailed description and the accompanying drawings are illustrative, and that the improvements herein disclosed may be embodied in varione forms of construction within the scope of the appended claims.

I claim:

1. In a centrifugal apparatus comprising a centrifugal basket rotatable on a vertical axis and having a bottom outlet for solids, a tapered bottom valve normally closing said outlet but liftable and tiltable simultaneously to expose part of the same, and a valve operating device extending inside the basket including a member swingable entirely therewithin to lift said valve at a point thereof on one side of said axis so that the valve tilts inward within the basket to expose said outlet on the other side, said swingable member being an arm on a fixed horizontal pivot inside the basket, said operating device also including power operated means fixed above the basket containing a reciprocable plunger and a vertically movable push-pull connection extending inside the basket between said plunger and one end of said arm.

2. Centrifugal apparatus as described in claim 1, said connection comprising a rod pivotally connected at opposite ends with the plunger and the driving end of said arm.

3. in a centrifugal apparatus comprising a centrifugal basket rotatable on a vertical axis and having a bottom outlet for solids, a tapered bottom valve normally closing said outlet but liftable and tiltable simultaneously to expose part of the same, and a valve operating device extending inside the basket including a member swingable therewithin to lift said valve at a point thereof on one side of said axis so that the valve tilts inward within the basket to expose said outlet on the other side, said swingable member being an arm on a fixed horizontal pivot inside the basket, said operating device also including a power operated means fixed above the basket containing a reciprocable plunger and a vertically movable push-pull connection between said plunger and one end of said arm, and a fixed sheltering tuoe extending downward into the basket around said connection to a point near said pivot.

4. Apparatus as described in claim 3, said pivot being mounted on a projection from the lower end of said tube.

5. A valve lifting device for centrifugal apparatus of the character described, comprising a motor adapted to be mounted over a centrifugal basket and containing a reciprocable driving member, a tube associated with the motor to extend downward therefrom to an open lower end fixed within the basket, a lateral and downward projection from the open end of said tube, an arm carried pivotally on said projection within the basket, a driven end of said arm underlying the open end of the tube and the arm having a free end formed to engage and lift a basket bottom valve, and a connecting rod joined pivotally at one end with said driven end and extending through said tube to a connection at its other end with said reciprocable driving member.

6. In a centrifugal apparatus comprising a centrifugal basket rotatable on a vertical axis and having a top opening and a bottom outlet for the escape of solids removed by discharger action at one side of said axis, and a bottom valve normally closing said outlet but liftable and tiltable to expose the same, a valve operating device including a relatively fixed support to extend downwardly into the basket through its top opening, a horizontal fulcrum on a lower part of said support, a valve lifting arm swingably mounted on said fulcrum for movement in an upright arcuate path entirely within the basket and displaced angularly from the zone of discharger action in spaced relation to said axis, said arm having a driven end extending to a side of said fulcrum away from said valve and a body normally hanging downwardly from said fulcrum and terminating in a free end normally disengaged from said valve, a fluid pressure cylinder fixed above said basket and having a vertically reciprocable plunger, and means including a vertically reciprocable rod within said basket connecting said plunger with said driven arm end for swinging the arm about said fulcrum in said upright arcuate path, said valve having a frusto-conical body to cover said outlet and a laterally extended collar portion thereabove normally projecting across the path of said free end.

7. In a centrifugal apparatus comprising a centrifugal basket rotatable on a vertical axis and having a top opening and a bottom outlet for the escape of solids removed by discharger action at one side of said axis, and a bottom valve normally closing said outlet but liftable and tiltable to expose the same, a valve operating device including relatively fixed support to extend downwardly into the basket through its top opening, a horizontal fulcrum on a lower part of said support, a valve lifting arm swingably mounted on said fulcrum for movement in an upright arcurate path entirely within the basket and displaced angularly from the zone of discharger action in spaced relation to said axis, said arm having a driven end extending to a side of said fulcrum away from said valve and a body normally hanging downwardly from said fulcrum and terminating in a free end normally disengaged from said valve, 2. fluid pressure cylinder fixed above said basket and having a vertically reciprccable plunger, and means including a vertically reciprocable rod within said basket connecting said plunger with said driven arm end for swinging the arm about said fulcrum in said upright arcuate path, said valve having a frusto-conical body to cover said outlet and a laterally extended collar portion thereabove projecting across the path of said free end, said cylinder being mounted with a part of said support above the basket and said support comprising a vertical tube extending downwardly through said basket opening and surrounding and sheltering the means connecting said plunger with said driven arm end.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 302,611 Weston July 29, 1884 719,476 Laidlaw Feb. 3, 1903 722,730 MacFarlane et al Mar. 17, 1903 1,298,451 Bryson Mar. 25, 1919 1,474,331 Robertson et a1. Nov. 13, 1923 1,633,570 Carroll June 28, 1927 1,903,298 Roberts Apr. 4, 1933 1,909,188 Roberts May 16, 1933 1,940,812 Roberts Dec. 2.6, 1933 2,517,409 Olcott Aug. 1, 1950 FOREIGN PATENTS Number Country Date 23,936 Great Britain of 1909

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