US1905306A - Centrifugal apparatus - Google Patents

Description

April 25, 1933.

E. ROBERTS CENTRIFUGAL APPARATUS Filed April 10, 1928 2 Sheets-Sheet l g n/M 6%f01 1163 E. ROBERTS CENTRIFUGAL APPARATUS April 25, 1933.

2 Sheets-Sheet 2 Filed April 10, 1928 in/M Patented Apr. 25, 1933 UNITED STATES ENT: OFFICE?- 13: EUGENE nonnn'rs, or ms'rmes, NEW YORK, AssIeNOn T THE-WESTERN srAr-Es MACHINE COMPANY, or SALT LAKEOITY, UTAH, A CORPORATION or UTAH CENTRITUGAL APPARATUS I rials from which the liquid content is centrifugally extracted.

In the treatment of brown sugar-or partly refined sugar there is frequently used What is known as a self-discharging basket, that is, a centrifugal basket having a steeply inclined frusto-conical bottom with a central discharge opening, the inclination being sufficiently steep to allow that grade of sugar, if properly treated, to slide through the bottom of the basket when the basket comes to rest.

In such baskets, the material to be treated is introduced into the basket when the basket is running at high speed and is naturally thrown against the peripheral wall of'the basket by centrifugal force and retained there during the purging and washing opera tions. This low grade sugar is of such a nature that under proper treatment, it does not 5 pack tightly enough in the basket to prevent 5 sugar into the basket, particularly if the basket be charged before coming up to proper speed to wall-up the material against the peripheral wall, considerable of the material may fall through the bottom into the conveyor for conducting away the refined mate rial and, by its mixturevwith said refined material, produce an inferior or unsatisfactory mixture. To guard against this and other troubles, I have provided a self-opening valve constructed and arranged to prevent the accidental escape of material when charging the basket, While being capable of automatically opening when the basket'is slowing down to the stopping point preparatory to allowing the discharge ofthepurified sugar.

To this end my invention comprises, generally speaking, in combination with a centrifugal basket of the self-discharging type, avalve member loosely mounted on the suspension shaft or spindle of the basket to be Application filed A ril 1:0,

1928. Serial Nbfizesezs.

slid-able thereon so that it may remain seated! against theinclined bottom of the basket dur mg the normal or high speed rotation of the basket, while being capable of lifting to un-- cover the discharge opening in the basket i3 when the machine is slowed -down preparat-ory to allowing the material to discharge through the bottom of the basket. In the case of the purification of white sugar, this type of basket has not heretofore been practical, because the white sugar packs so firmly into the basket that usually its weight'alone is insuflicient to-dislodge it from the basket'when the basket rotation-ceases. Heretofore, in the centrifugal treatment of white-sugar, orsimilar-material that packs firmly into the basket, it has been customary to use a flat bottom basket and to discharge the "sugar by slowly rotating the basket against "a di'scharger plow. A further feature of mypresent invention includesmeans for s'oftenin'g'or loosening the outer surface of the sugar wall in contact with the basket, so that this gradeof sugar or material may also be automatically discharged without the aid of'a plow through its own gravity." 1 f These and other features of my present invention will be particularly described in the following-specification and will be defined in the claims'hereto annexed. y In the accompanying drawings I have -il'-' lustrated a simple and convenient embodi ment of my invention, inwhich Fig. 1 is a side elevation partly in section showinga wellknown type of centrifugal machine provided with my aforesaid improvem'ents.

Fig. 2 is adetail showing in front elevation a part of the connecting mechanism by which a steam'cu't-ofi'valve is opened in proper coordination with the centrifugal basket valve mechanism when the power isshut' olf.

Figures 3 and 4 are details showing, in side elevation, enlarged views of the steam valve controlling mechanism, the former showing the control mechanism in open position of the" steam valve, while the latter shows the same mechanism withdrawn'from valve operating position to allow the valve to'close.

the 'gyratory suspension spindle or shaft 4?.

This basket shaft or spindle has an enlarged upward extension 4 supported by radial bearings upon the usual gyratory suspension element which, in a manner wellknown in the art, is mounted in a socket and hanger5 secured to the overhead horizontal beams 6 that are carried alongside the usual mixer.

In the belt driven type of machine a com-.

bined driving and brake pulley is secured to the rotary shaft to project around the gymtory centre and receive an external drivingv belt 8 which passes rearwardly to a driving pulley on the line shaft energized according to usual practice by a clutch under the control of a .conveniently located hand lever 9 overhanging the front portion of the machine.

Thehand lever 9 in the forward position illustrated in Figure l'is in the centrifugal operating position and, when movedrearwardly, releases the driving clutch and sets the brake inside the pulley 7 All these features thus far described are such common practiceiand so wellknown in the centrifugal,

art, that illustration of the details is omitted. I have also omitted showing the interior filter linings ofthe basket which prevent the escape of the solid particles through the basket wall andbottom, while allowing the liquid to escape through perforationstherein, a On the basket spindle t is mounted a sleeve or tubular member 12 carrying at its lower end a downward flared or conical extension 13, preferably made of light sheet metal, whosebottom edge is reinforced by a metallic ring 13 adapted to set against the lower por tion of the inclinedpart of the conical basket bottom, so as toprevent the escape of the contained material from the basket when the valve is seated upon the bottom, At its upper end the loosely fitting sleeve 12 is provided witha flanged, collar 14; which. overhangs anti-frictional wheel 16 carried in the forked end of the lever 15. This lever is fulcrumed in a bracket 17 mounted on top of the surrounding casing or curb 10 and is provided with an'adjustable actuating member, in this case a Weight 18, which istslidable along the lever and may be secured in any desired position of adjustment by the set screw 18 in order to vary the actuating force exerted by it to lift the valvefrom closing to open position.

Assumingthe baskettobe empty and at rest, the valve lever will then act to support the basket valve in raised position, the control lever 9 then being in its rearward position. As the operator starts the machine by pulling the lever 9 forward to operating position, he presses the valve13 downward until it seats against the basket bottom in basket closing position. When the basket has acquired a moderate speed the frictional clutching action, due to such rotation, establishes suflicient frictional grip between the basket spindle and the surrounding valve rotating therewith to overcome thelifting action of the lever 15, so that the valve remains in closed position, while the material to be treated is admitted to the basket through the usual spout and during the subsequent purging and washing and drying operations of the machine when-it is running at normal operative speed.

- When the lever 9 is returned to power releasing and brake setting position to allow the machine to slow down preparatory to discharging or unloading, this clutching action is weakened until a point is reached, according to the adjustment of the actuating member 18, where the clutching action is overcome by the weight of the actuating element 18, so that the valve is lifted to open position preparatory topermitting the sugar to slide out of the basket through the bottom when the basket stops rotating. The period intervening between the throwing of the centrifugal control lever 9 to idle position and the actual lifting of the valve before the machine actually stops, will depend' upon the adjustment of the lever actuating member 18 and may, of course, be varied by the setting of that member.

To prevent any accidental and unintended opening of the valve, which would allow the basket contents to unload in case the driving power should be accidentally interrupted or cut off, such as by breakage of the driving belt in the case of a belt driven machine, or the failure of current in the case of a motor driven machine, I provide protective means so arranged that the valve remains closed even when the machine is at rest if the starting lever occupies normal operating position.

A rock shaft 35 is mounted in overhead hangers 35 and has secured to one end an arm 36', whose free end is connected by a link 37 with the valve lifting lever 15, the link member being threaded for extensible adj ustment to properly set the device. To said rock shaft is also secured an arm 40 which, at its free end, has a laterally projecting pin 41 projecting through a slot 33 in a rearwardly extending link 32, that is, connected at its forward end with the starting or control lever 9. This is so constructed and proportioned that the pin ll will be engaged by the rear end of the slot when the starting lever 9 is in operating position and when the valve opening lever 15 is closed position, as indicatedin Figure 1. Consequently the rock shaft 35 is held by the'slot'tedlink against clock-wise rotation while the lever 9 is in for-:

ward or operating position, thereby preventmg the lifting of the inner end of the lever a which encases the valve so that at all times,

when the lever is in operating position, the valve is positively prevented from lifting.

On the other hand, when the lever is returned either by hand or automatically, as

V the case may be, to rearward or non-operating position to permit the slowing down and stopping of the machine, the levers 4G and 36 will remain in the same or valve closing position, until such time as the clutching of a the valve upon the spindle is reduced to the basket available for use on white sugar, or'

on any grade of material, and thus get rid of discharging the material by means of a discharger plow operated by the attendant, I have made provision for loosening the walled-up material by means of asteam jet that is applied for a brief interval between 30, the shifting of the control leverito. idle position and the lifting of the valve to open or discharge position and I utilize the valve lifting mechanism to cut off the steam jets automatically after the sugar has been ex- 7 posed to its softening action for a suificient period of time to accomplish the desired purpose. This can be readily effected, since there is a substantial interval elapsing after the control lever returns to idle position before the basket slows down enough to allow the valve to lift. Moreover, this interval, as above explained, may be varied by adjustment of the valve lifting means to meet all practical requirements.

The loosening of walled-up grains of material is eifected by means of plural steam jets issuing from jet nozzles arranged adjacent to the basket and inside the curb on a steam supply pipe 21.

The steam supply pipe is provided with a hand cut-off valve 22 and also with an automatically controlled valve 23 of the plunger type. The valve fitting is provided with a fixed bracket 24: in which is pivotally mounted, intermediate of its length, a valve controlling lever 25, which is provided with a counterbalance weight 26 or equivalent device for normally closing and keeping this valve closed. The upper end of the valve lever is arranged in substantial alignment with the link 32. This link carries a pawl 30 which is pivoted to the link at 31 and extends rearwardly with its rear end dropped:

to the plane of the pivotal centre 31. This pawl, intermediate of its ends, rests loosely upon-theupperor free end of the arm 40, which arm is provided with a projecting nose 42 which performs no function when the arm is in valve closing position, but which acts when the arm 40 swings to valve-opening positionto lift the free end of the latch or pawl 30 out of engagement with the upper end of the steam valve controlling lever 25.

Parts,-as shownin Figure 1, occupy the normal position when the centrifugal is running with the controllever in forward posi-- t-ion, the basket valve closed and the steam V valve also closed by its actuating weight 26.

When the lever 9 is moved rearwardly to idle position, the pawl 30then in engagement with the upper end of thesteam controlling valve lever 25 forces the valve lever 25 rearwardly on its fulcrum, the thrust being in line with the pivotal centre 31 of the pawl or latch. This opens the steam valve and holds it in open position until the basket has slowed down sufficiently to allow the basket valve liftingmechanism to operate, thus bringing the nose 42 of the arm 40 into lifting contact with the underside of the latch 30, thereby lifting the free end of said latch above andout of engagement with. the adjacent endof the steam valve lever which allows the actuating member 26 to close the steam valve to cut off the steam supply. I

. A few seconds later the basket stops and the sugar automatically dischargesthrough the uncovered bottom discharge opening. When the attendant is ready to start and reload the machine, he throws the lever 9 forward. to operating position and thereby,

through the slotted link 32, -movesthe arm 40 and the co-acting' valve mechanism to valve closing position, so that the valve is closed and kept closed before the centrifugal acquires speed enough to produce clutching action to interfere with the closing of the valve.

It'will therefore be seen that as soon as the centrifugal controlling lever returns to idle position to slow down and stop the basket, but while the basket is still revolving, the steam jets are directed against the perforated wall of the basket to loosen the sugar. This action continues for a few seconds when the further slowingdown ofthe machine, ac cording to-the adjustment of the counterweight 18 allows the lifting mechanism to open the valve and at the same time out off the steam jets, 1 I The advantage of connecting the basket valve closing mechanism with the control lever is that it avoids any trouble due to negligence or forgetfulness of the workman to close the valve and, also prevents the un-' the mingling of the untreated sugar in case the basket is loaded before the machine is rotating rapidly enough to cause the material to wall-up against the basket Wall.

What I claim is: I

1. Ina sugar centrifugal apparatus the combination with a suspended gyratory centrifugal whose basket has a frustoconical bottom with a central discharge opening, a bottom closing valve slidably mounted on the basket suspending shaft, and self-acting means for lifting said valve from bottom closin g position when the centrifugal has slowed down to a predetermined speed.

2. In a sugar centrifugal apparatus the combination with a centrifugal basket having a steeply inclined frusto-conical bottom with a central discharge opening, a bottom closing valve slidably mounted on the basket shaft toseat against the bottom and prevent escape of the contained material through the bottom opening, and valve lifting means normally rendered inoperative through the rotation of the basket at operating speed, while acting when the basket rotates at low speed tolift the valve and uncover the discharge opening .preparatory'to allowing the contained material to discharge of its own weight through the bottom of the basket.

3. A gyratory centrifugal whose suspended basket'has a steeply inclined bottom provided with a central discharge opening combined with a hollow valve of-substantially conical form slidably mounted on the sus pension shaft to close said bottom opening against-the escape of the contained material, and aself-acting valve-actuating member operating to lift said valve to open positionwhen the centrifugal has slowed down to a predetermined speed.

4. A gyratory centrifugal whose suspended basket has a steeply inclined bottom with a central discharge opening, combined with a hollow valve of substantially conical form having an upwardly extending tubular sleeve loosely engaging the basket suspending shaft to permit the valve to slide freely upon said shaft when the machine is rotating at a relatively low speed, while acting through the clutching engagement produced by rotation at normal operating speed to frictionally prevent the movement of said valve on the shaft substantially as described.

5. A gyratory centrifugal whose suspended basket has a steeply inclined bottom provided with a central discharge opening, combined with a bottom closing valve slidably mounted on the basket suspending shaft, self-acting means operating to lift said valve to open position when the machine has slowed down toa predetermined speed, said valve lifting means being adjustable to permit it to become operative at different predetermined speeds of the centrifugal.

6. .The combination with a suspended gyratory centrifugal whose basket has a steeply inclined bottom with a central discharge opening, of a closure valve for said opening, self-acting means for lifting said valve from its seat to open position when the centrifugal has slowed down below a predeterinined speed, and means cooperatively associated with said valve to loosen the walled up material in thebasket to assist its discharge therefrom.

7. The combination with a gyratory centrifugal whose suspended basket has a steeply inclined bottom provided with a central dis charge opening, and a controlling lever by means of which the centrifugal is started and stopped, of a bottom closing valve, self-acting'means for lifting said valve to open position when the centrifugal has slowed down to a predetermined speed, said valve lifting means being interconnected with the starting lever to prevent the lifting of the valve when the starting lever is in normal operating position. I

8. A self-discharging centrifugal embracing in combination with a suspended open bottom basket and a control element by which the centrifugal is started and stopped, a bottom closing valve means for lifting the valve from closing position, said means becoming operative only when the basket has slowed down to a predetermined speed, and means for preventing the lifting of the valve when the control element is in normal centrifugal operating position.

9. In combination with a sugar centrifugal and means controlling the starting and stopping thereof, a steam supply pipe constructed and arranged to deliver steam jets against the outside of the centrifugal basket, means acting to open said valve when the controlling means is set to stopping position and means acting after the centrifugal has slowed down to allow the cut-off valve to return to closed position.

10. The combination with a sugar centrifugal having an open bottom basket and a control lever for effecting the starting and stopping of the centrifugal, a bottom-closing valve, means for directing jets of steam against the basket, a steam cut-off valve, the starting lever, the bottom-closing valve, and the steam cut-off valve being operatively coordinated to effect the opening of the steam valvethrough the agency of the control lever moving to stopping position and to close the cut-off when the bottom-closing valve moves to open position. v f

11. The combination with a sugar centrifugal having an open bottom basket and a control lever for effecting the starting and stop ping of the centrifugal, abottom-closing valve, means for directing steam against the basket to loosen the material therein, a steam cut-off valve, means acting under the control of the starting lever to open said cut-ofi' valve and, after proper sequence, closing said valve and allowing the bottom-closing valve to move to open position when the centrifugal has slowed down to a predetermined speed,

said controlling means acting to reset the bottom valve to closed position when the starting lever is shifted to operating position.

12. The combination with a centrifugal having an open bottom basket and a starting and stopping lever, means for directing steam against said basket to loosen the material therein, a steam cut-off valve actuated by a counterbalance lever to open position when the centrifugal has slowed down to a predetermined speed, a link, a pawl actuated thereby to open the cut-off valve when the control lever is shifted to non-operating position, said link and said pawl and said counterbalance lever being co-ordina-ted to effect the opening of the cut-off valve and the subsequent opening of the bottom-closing valve when the control lever is shifted to non-operating position, while causing the closing of the bottom-closing valve when the lever is moved to operating position.

13. A centrifugal apparatus embracing in combination a gyratory centrifugal having an open bottom basket and a control lever for starting and stopping the centrifugal, means for directing steam against the centrifugal basket to loosen the material therein, a steam cut-off valve, means for raising said bottomclosing valve to open position when the centrifugal has slowed down to a predeterminedspeed, a connecting link, a pawl actuated thereby for opening said steam cut-off valve, a rock arm actuated when the control lever is in non-operating position to release said pawl from actuating position when the bottom-closing valve moves to open position.

In witness whereof, I have subscribed the above specification.

EUGENE ROBERTS.

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