US2638225A - Control mechanism for centrifugal charging valves - Google Patents

Description

B. G. COX

CONTROL MECHANISM FOR CENTRIFUGAL CHARGING VALVES Filed Sept. 5. 1947 2 Sheets-Sheet l y 2, 1953 B. G. cox 2,638,225

. CONTROL MECHANISM FOR CENTRIFUGAL CHARGING VALVES Filed Sept. 5, 1947 2 Sheets-Sheet 2 W ii- 177' TOR/VI X Patented May 12, 1953 UNITED STATES PATENT OFFICE CONTROL MECHANISM FOR CENTRIFUGAL CHARGING VALVES tion of New York Application September 5, 1947, Serial No. 772,367

This invention relatesto charging valves for centrifugals and to a control therefor, the principal object being the provision of a charging valve having certain new and useful characteristics and a novel control for the valve for closing it when it appears imminent that an excessive charge is being discharged through the charging valve of the centrifugal.

Objects of the invention include the provision of a charging valve particularly adaptable for use in connection with centrifugals so constructed and arranged as to minimize, or completely prevent, the possibility of leakage from the valve 2 Claims. (Cl. 210-63) one form of centrifugal apparatus of the type to which the present invention may be adapted, showing the valve and the control mechanism therefor of the present invention in operative relation with respect thereto;

Figure 2 is an enlarged, fragmentary, partially broken, partially sectioned view of that part of the mechanism shown in Figure 1 including the charging valve and its control mechanism, to

from dripping or flowing into the centrifugal;

the provision of a valve of the type described providing means for receiving and holding liquid dripping or otherwise escaping between the relatively movable surfaces of the valve when in the closed position; and the provision of a valve of the type described including a movable member providing a drip collecting pocket when in closed position.

Further objects of the invention include control means for a valve of the type described including a member adapted to project into the interior of the centrifugal basket while the valve is open and adapted to be contacted and moved by an excessive charge in the centrifugal basket, thereby to actuate the valve operating mechanism to move the valve to closed position; the provision of a construction above described in which that part of the mechanism which projects into the centrifugal basket is Withdrawn from the basket when the valve is moved to its closed position; the provision of a construction as above described in which, when the said mechanism is withdrawn from the basket, it is so positioned that any drip therefrom is prevented from dripping back into the centrifugal basket; and the provision of mechanism of the type described in which the movable part of the control mechanism is positively connected to the valve mechanism for interrelated movement therewith.

The above being among the objects of the present invention the same consists in certain novel features of construction and combinations of parts to be hereinafter described with reference to the accompanying drawings, and then claimed, having the above and other objects in view.

In the accompanying drawings which illustrate a suitable embodiment of the present invention and in which like numerals refer to like parts throughout the several difierent views,

Figure 1 is a fragmentary, partially broken, vertical sectional view taken centrally through ill better illustrate the same, the charging valve being shown in closed position;

Figure 3 is a still further enlarged, partially broken, partially sectioned view, taken in the same direction a the views in Figures 1 and 2, but in greater detail showing the charging valve itself, in closed position;

Figure 4 is a fragmentary sectional view taken on the line 4-4 of Figure 3;

Figure 5 is a view similar to Figure 2, but showing the valve in its open position, and control mechanism with its limit gauge in lowered position;

Figure 6 is a fragmentary, partially broken plan view of the valve and its control with the valve in the position illustrated in Figure 2;

Figure '7 is a View similar to Figure 6, but illustrating the valve and its control mechanism in the position shown in Figure 5, and

Figure 8 is an enlarged, partially broken, side elevational view of the control mechanism inits raised position.

Although the present invention is applicable to any type of centrifugal, and regardless of the material to be processed thereby, it is particularly applicable to centrifugals employed for use in the sugar industry. Accordingly, for the purpose of description, the centrifugal shown in the accompanying drawings is of the vertical type and will be described only in its relation to its use as a sugar centrifugal, its application to other types of machines and other uses thereby being made apparent to those skilled in the art.

Centrifugals employed in the sugar industry are usually automatically controlled in such a manner that the various phases of operations follow each other in succession, and an allotted time period is provided for each phase of operation. For instance, the charging valve is automatically opened and remains open for a predetermined period of time, upon the termination of which it closes. A time interval is provided during which no charging occurs, so as to discharge all of the syrup remaining in the centrifugal basket from the basket, then wash water 2 is automatically introduced into the basket to wash the syrup from the crystals therein and is turned off after a predetermined period of time; the basket continues to rotate for a predetermined time to dry the crystals of sugar in the basket, and then a pushing mechanism provided for discharging the crystals is operated to discharge the crystals. and is then returned to its original position, upon which the charging valve is again opened and the above described sequence of operations is automatically repeated Because of variations in pressureon theliquid being charged to the centrifugal, its relative concentration, or for other reasons, there is a possibility that the layer of sugar crystals in the basket will build up at a faster rate thanccntemplated, and under such conditions if the charging valve is allowed to remain open its full allotment of time the centrifugal basket will overflow, either with syrup or sugar crystals, the occurrence of either of which is undesirable.

The present. invention: provide-s a safeguard fromsuch overloading, andv this is accomplished by meansof a limit or." thickness gage: which. is placed. in operative position. in the centrifugal basket when the charging valve is openedand is positioned to be contacted by layer of crystals of sugar inxthe basket after they have built up to a predetermined" max'nurn thickmess on the-screen. Upon: contact v -th the'layer of crystals the limit gage moved toactuate an electric switch whichinx turn closes the charging valve so thatno more syrup is discharged into the centrifugal. chamber or basket.

An important feature of the invention is the withdrawal of the limit gage from within the centrifugal chamber or basket. when the charging valve is'cloeed and into. such. a position that any syrup dripping. from: the gage will not drip into thecentrifugal chamber; but'will be removed to a position away: from the crystals in the i,

chamber or' basket.

A further feature of the present invention is the construction and; arrangement of the chars" ing valve itself which: is so constructed and; arranged as to. prevent syrup, which leaks between theimcvable'parts, from dripping into the basket and: uponv the sugar. crystals, causing them to lump or coalesce;

Referring now to the accompanying drawhires and. particularly to Figure 1, a charging valve indicated generally at it andr'a control mechanism therefor indicated generally at E2, constructed according to the-present invention, areishown association-with asugar centrifugal;

While the present invention is to any suitable. type or construction of centrifugal, the particular centrifugal shown by way of illustration is that. shown and claimed in the-copending application of- Thomas Evans and. the present applicant; ior improvements in Gentriiugals, filed September 19, 1947 and serially numbered 774,- 9'70. Briefly; it comprises a suitable framework: i l supporting on its top a driving motor it arranged with. axis. vertical. adapted; to rotate a shaft t8 thelower end. of which has fixed thereto a circular dish-like portion constituting a stripper or pusher non-rotatably received within a centrifugal screen or basket 22, which forms the centrifugal chamber, and which isprovidedwith a substantially closed and imperiorate bottom wall 24 fixed thereto. The basket 22 is adapted to beraised or lowered by means of a piston (not. shown) received in the coaxial cylinder 25 below the wall 2 3. A curb ring ils is positioned at. the. upper end of the T from and led to a suitable point oi": deposit.

4 basket and rotates therewith and limits the upper movement of the syrup and crystals in the basket 22 under centrifugal action during operation. The curb ring is fixed with respect to the pusher or stripper 2c. The basket 23 over its height is enclosed. by an imperforate wall 33 arranged in outwardly spaced: relation" with respect thereto which receives the liquids thrown ofiby the basket 2i. and which liquids are drained there- It will be understoodv that after syrup has been introduced; into the basket 22 through the valve it? for a sufficient length of time to permit a desired: body of. crystals to be built up in the baslret Z-Z, the valveas is closed, the basket continues to rotate until all the liquid is discharged from. the: basket, wash water is introduced into the basket 22 to wash the syrup from the crysteas; and after this water has been thrown off and the basket has continued to rotate for a tlcngthoi time-todry he-cry the piston in the cylinderi. isaactuated to lot the basket. which action. lifitsthe: curb ring: 28- and: pusher 2E3; relative to: the basketv 22 so as to force the crystalsofi overth'e-top of the basket, after which the basket; is; raised to re-estabiish its" normal pcsition'with respect to thepusher 28A and curb ring 2.23, the charging valve then. opened. and the operations repeated.

The valve=- leis connected: to a supply duct 35 which: leads to"v a: suitablesupply of: syrupwhich isto becentriiuged. Asibestbrought outincFigs. San-d ethe'valve: ldcomprises a: hollow body 36; openiat both endsand preferablyof: square-cross sectional configuration as: shown. It isprovided with: azsin'roun'ding outwardly directed flange 38 serving a; mounting: therefor inasmuch: as it is: suitably. secured: to a bracket. id fixed: to th'e cover. #12 0c the centrifugal. The forward end oi the bodiv id is curved-' to conform. to a' part of thecylindr-ical surface having. a: horizontal? axis passing through the body 35 midway of its-upper andjlowen walls and is" closed by Y a swinging; shut ten-orrval-ve plate. Mia The valve plate 55: is wider than the body 3:6, as brought out inFig; l, and integrally secured to: each; opposite end edge thereof is. a. radially; inwardly extending side plate; 4'32 Each plate tit, on the axis 1 of. rotation of thervalve plater lfi', is-zprov-ided, with an axially inwardly; extending: pivot pin 53 which is. rctatably. received i111 a: block: d'z'locatedon the corresponding sideoi' the body bit-and longitudinally adiustably' secured to an. outwardly projecting flange 54' on the body by-means of a pair of screws 53 passing'through slots till-in tlie'flanges 51%. Tocontrol this adjustment,- a screw 62 is projectedithroughan. extension t l-oi the flange 3%. and: threads into i said block.

its; best brought out in Figure 3, it will be noted that; thevalve plate as ofgreater arcuate: leng t-h than; the-curved outer. end ofthe be dy 351. Whenzthe valve plate it is in closed position, its lower-endzxprojectsa material: distance rearwardly-beyond. a vertical plancincluding the axes? of the pins- 5d. so that, as: illustrated in Figure 3, adrip collecting: pocket is formed in the: lower portionof. the valve; plate dd between the side plates 48;- Thepurpose forming this pocket-1 is to provide a. means; for catching and storing anyleakageof liquid between the nozzle body 3th and: the valve plate 45-, and so that, shouldqsuchleakage develop, it' will form apool such as indicatedat 56? in Figure 3 in the bottom portion oftheplate lts. When the valve. H3 is opened: any liquid inxth'e pocket: 66? will be; discharged either onto the curb ring 28 or into the basket 22. i I

The reason why it is the desire to prevent any dripping from the nozzle I0 when in closed position is that, should syrup drip from the nozzle into the basket of the centrifugal after the washingoperation on the crystals has been completed andbefore the crystals have been discharged from the basket, such drippings of syrup would cause the crystals wet thereby to coalesce with one another and to form undesirable lumps in the crystalline sugar. In this connection it may be also noted in Figure 3 that the valve plate 46 in closely adjacent'relationship with respect to its lower edge is provided with a transverse flange or bafile 10, extending the full width thereof, so that should the pool 66 OVGIfiOWIthC lower edge of the valve plate 46 ans. tend to flow to the lowermost point of the valve plate, the bafile will intercept such flow and cause it to drip from the valve plate before it reaches such lower point. The purpose of this is that, as brought out in Figure 3, the valve Iflis'so positioned with respect to the curb ring 28 that should any such overflow of the fluid 66 occur and be drained from the valve plate by the baffle Ill, such drainage, as indicated in Figure 3, will drain upon the curb ring 28 and not into the basket 22. The curb ring 28 rotating under the conditions assumed, any such drippings fed to it will be thrown centrifugally radially outwardly and prevented from entering the basket 22.

In opening the valve ID, the valve plate 46 is rotated in a counterclockwise direction from its closed position illustrated in Figure 3 to its open position which is illustrated in Figure 5. To control the movements of the valve plate 46 a lever arm I2 is fixed at one end to one of the side plates 48. Its free end is connected to any suitable type "of power means, shown by way of illustration as a piston and cylinder assembly. In such case, the free end of the lever 12 is connected by a clevis I4 and pin it to the outer end of the piston rod 18 of a piston and cylinder assembly 80 pivotally mounted at its outer end as by means of a pin 82 to the supply duct 34 about an axis parallel to the pivotal axis of the valve plate 46.

The assembly 86 comprises a cylinder 8241 within which a piston 84 is reciprocably received and fixed to the inner end of the piston rod 18. The upper or left-hand end of the cylinder 80 is closed and the lower right-hand end thereof is closed except for the opening necessary for passage of the piston rod 18 therethrough and which is sealed with respect to said piston rod. A tube 66 leads into one end of the cylinder 82 and the tube 38 leads into the opposite end, the tubes 26 and 38 leading to a solenoid operated valve indicated generally at as in Figure 1 having an inlet or'supply pipe 92 and a discharge pipe 94. The solenoid valve 90 is of the conventional type spring pressed towards one position, preferably that in Which the supply pipe 92 is placed in communication With the tube 88 and the tube 86 with'the discharge duct 94, so as to move the piston 84 to valve closed position, and whenenergized the valve is actuated to connect the supply pipe 92 with the tube 86 and connect the tube 88 with the discharge duct 94, so as to move the valve to open position.

As previously explained, where apparatus of the type described is automatically controlled, a suitable timer mechanism is provided which acts to energize the solenoid valve 90 to open the charging valve Iii at a particular point in each cycle of operation, and after a predetermined time ele- ,with the lever 12.

ment has expired deenergizes the solenoid so as to close the valve I0, and that if, for some reason or other, an excessive charge tends to build up in the basket 22 before the control mechanism is actuated to close the valve 1 0, means are preferably provided actuated by the excessive charge in the basket 22. to closethe valve in before the predetermined time for closing the same has expired. Broadly, this is an old idea, but the mechanism provided in accordance with. the present invention is believed to be new and to involve a new principal of operation. This part of the apparatus will now be described.

In that part of the invention dealing with the control of the valve in event of excessive charge therethrough to the basket 22, it will be noted that in the specific form of the invention shown on the cover 4?. opposite the valve I0 is mounted, an L-shaped bracket member Ifiii, one leg of which lies in flat contacting relation with respect to the cover 42 to which it is suitably secured, and the other leg of which projects vertically upwardly and preferably lies in a plane parallel to a vertical plane including the axes of the valve Ill and supply duct 34, and is generally in alignment The bracket I00 is provided with a slot I02 in its vertical flange, such slot extending from a point near the outer end of the bracket Ito in parallel relation to the bottom flange thereof, and at a constant width, to a point adjacent the opposite end of the bracket-where it joins a vertically directed portion II'M the upper end of which is on substantially the same level as the upper edge of the horizontal portion of slot I02.

The bracket IIlIl mounts a carriage, the construction and mounting of which will now be described. As best brought out in Figure 8 the carriage comprises a generally lJ-shaped member I I2, the opposite ends of which are provided with aligned and elongated sleeve portions I i4 and H6, respectively. As best brought out in Figure 8, a screw III! and a pin I29 arranged in spaced and parallel relation with respect to each other and perpendicular to the plane of the vertical flange of the bracket IIlfi project through the base of the carriage H2 and through the slot I02 Within which each rotatably receives thereon a roller I22 of substantially the same diameter as the width of the slot I632. On the opposite side of the vertical flange of the bracket i0!) is a retainer plate I24 through which the screw I I8 and pin I20 project, the former receiving a nut I26 outwardly of the plate I24. A shifting member for the carriage I I2, shown in the form of a link I28, operatively connects the valve mechanism I0 to the carriage H2.

The link I28 is apertured for reception of the pin I20 connecting it to the carriage.' The opposite end of the lever I138 is similarly formed and is pivoted to the piston rod 78 by the same pin I6 which connects the clevis M to the lever 12. Int-his manner, carriage Iii? connected to the valve In for simultaneous movement therewith.

The carriage is of course supported by the rollers I22 for movement in a direction of the length of the slot I02. The link I28 is of such length that whenthe valve It is in closed position the carriage [I2 is in its extreme outward position with respect to the axis of rotation of the centrifugal as shown in Figures 2 and 6, and when the valve is opened the carriage is moved toward its extreme inward position. In this last mentioned position, it will be noted that the inner- 7 most roller I 22: moves totheE bottom: of the ver tical slot portion tilt and the outer roller: I22 moves: into: the" upper portion of this" inner vertical portion of theslot', placing the-carriage I I: in" verticalv position.

Referring, again. to" Figure 8,. it will be noted thati a p in or shaft E li extends between and is journaled'inthe sleeve bosses I56 and" Hill of the carriage H2 That and eithe shaft hit which projects inwardly" beyond the" inner end of the corresponding: sleeve Ht has rigidly fi'xedth'ere to aradially outwardly directed plate-like part M2 which constitutes a limit or thickness gage; The: opposite. end. of the shaft Hit which-projects beyondt'hef outer end of the sleeve: llfihas fixed thereto the hub il i of a: quadrant shapedarm M5,, the" outer end of. which is" provided with an axially inwardly projecting portion: I43 which overliesa horizontal web l-Eil formed between th'e1-boss Hit and. the corresponding end of the carriage H2. A screw I52; threaded through the web I56. abuts the portion I53? to limit rotation of. the shaf t ass-mone direction. The shaft Mil is constantly urged in a direction of rotation tending, to urge theportion l l't'against the screw I52 by mean's'of a coil torsion spring I54 surrounding theshaft Mt; between the sleeves Ht H t and fixed at its" opposite ends in collars I53 and: 3 2 secured: to the sleeve lit and shaft l lll respectiveiy; The shifting means or links 128 as shown in" Fig; 5 operates, when the valve mechanism is actuated by the power means 89, to remove the" gage part Hi2 and the carriage H2 from". their'normal working position Within the basket, to their inoperative position outside the basket, asindicated in: Fig. 2.

Aswill be observed" from. the various figures of the: drawings, when the carriage" H2 is brought to thelimit of its movable position, as shown in Figs. 5- and'7, correspondingwitlr the open po'si tion of the valve iii and in which th'e'carriage is arranged vertically, the gage M2 has passed downwardly below the inner edge of the: curb ring, 26: and. into the interior of the basket 22, and at such time the gage M2 projects away from the shaft iii-ii in a generally radially outwardly directionwith: respect to the axis'of rotation of the basket 22'. It isithusin a position-tobe en'- gaged by an excessive-charge in-the basket 22,

and, when engaged by such charge, is adapted w to be movedtherebyin the direction of rotation of the charge and correspondingly rotate the shaft Mt against the force of the spring l5t. Rotation of this shaft is reliedupon to operate the solenoid valve B li-to close the valve H! so as to limitiurther" discharge of material from the valve into the basket 22, and this is accomplished in the following described manner.

The arm. Mt, as best brought out in Fig; '7, is formed as the quadrant'of acircle with. an. included angle of approximately 90. One end of this quadrant is out off at an angle as at HQ so as to constitute a camsuriace. A projection H2: is: formed at the opposite end of the. quadrant to act as a stop. The relation of the abovedescribed quadrant with-respect-togage i 52, when the parts arein their normal-operativeposition with thevalve l d;is-illustratedin Figure 7.

A-bracket l i iis mountedon the'upper face of the bracket HHS-.- It isprovided withan upstand" ing arm lit the upper'endbfwhich is located in transverse alignment to' the arm M6 on. the outer end of the shaft M0 when the carriage t|2.- is in its vertical. position. A.- conventional electrical switch 118 is secured to the upper end of: the: arm H6: The switch: H8 ever that-con ventional type which is spring pressed. toward closed position and-is provided-:witha projecting actuating pin I" which; when depressed, opens the-switch. The pin 1-80 project's inwardly to ward theaxis' of the shaft Mqrwhen: the carriage 2 is. in its vertical inner position, as brought out in Figure '7, and the pin iafl'is located in the cutaway portion: of the arm Mt forming." the cam l-l-il-z The centrifugal rotates in a: clockwise direction of? rotation; as viewed in Figure'l, so that, should the contents of the basket 22", and: particularly the-crystals of sugar, build: up to s'uchapoint as to contact the gage I42, it will cause theouter endof. the gage M2 to"- move'im the direction. of rotation of the material in: thebasket 22 and correspondingly rotate the'shaft MI! and arm '5 in-a; clockwise" direction of. rotation about the-axis of the shaft Hllhupon which movement the cam ill? of the arm M6 will contact the post 1 80 of switch.- lll' and depress it, moving the switch; to open: circuit position: The end of the post I80 will ride up onto the: arcuate portion of: the arm hit and move the switch M8 to open circuit position.

Assoon as the switch I! 8 is moved to open: circuit' position it breaks'the flow'of current to the solenoid i itch which then-immediately moves to a position to introducefluid'under pressure to the line 83 and exhaust fluid under pressure from the line 86, thus causing actuation of the piston S l in a direction to close the valve it); Because of the link 28; whenthe valve Hi thus movesto closed position, the carriage Hz is moved. to its inoperative position illustrated in- Figs.- 2-- and 6', which withdraws-the gage I 22 from the basket 22 and movesit outward-1y withrespect to' the axis of rotational? the basket beyond theinner. edge of. the curb 'ring zfl asbest brought out-in Fig; 6-. Thislastfeature is important in that any syrup which may have adhered tothe' gage I'M and associated parts of the carriage l-|2 mightotherwise drip bacirinto-the basket 22 if. the gage 142 or associated parts still. projected inwardly of the inner edge of the curb ring 23. before mentioned, such dripping of syrup would'be' undesirable-at a time when: the sugar crystals in the basket E i-were in a c'ond-ition to bra-discharged from the basket; for the introduction of: any syrup at this time would wet-sozne'of the crystals and cause them tocoalesce with one another, thereby-forming lumpsin' the-finalproduct. The curb ring 2 8:rotates withthebashet 22 so that any'clrippings falling on" it are throwncentrifu gally outwardly away from the basket.

Itm-ight also be noted-that as soon asthe: gage M2 is actuated under the. conditions above stated to open the switch 1 l8 and close the valve- W1, the carriage l"l2 ;.in moving to'its normally inopera-s the position, disengages the arm MS fromthe switch pest lll i, thereby returning the switch to its-normally closed position;

The automatic control of such centrifugals bcingconventional, a" diagram. to illustrate. the sameis not believed necessary to the proper understanding of the present invention and. is therefore nothere shown, but isshow-n and described in the copending applicationpreviously identified. For the purpose of illustration; however, it maybe noted' thatin-Fig. 1 one sideof the solenoid. valve "lifl 'isshown as being connected toa suitable source of current indicated at 190 and connected at its opposite side by a lead I92 .with theswitch H8;- '1?he-oppesite side ofthe switch is shown as being connected by a lead I94 through a switch indicated diagrammatically at I96 with the opposite side of a solenoid valve 90. The switch I96 is shown merely as illustrative of the switch mechanism in the automatic control usually provided in automatic centrifugals for controlling the solenoid valve 90 or the equivalent, controlling the opening and closing of the charging valve.

What is claimed is:

1. In a centrifuge having a supply duct and valve and a basket, power means for opening and closing said valve, a thickness gauge operable upon engagement with a predetermined thickness of material on the wall of the basket to actuate the power means in a direction to close the valve, said gauge including a rotatable shaft, a carriage supporting said shaft for rotational movement, a stationary bracket adjacent said basket and having a curved slot with substantially horizontal and vertical portions, said carriage being mounted in said slot, and a link extending between said valve and said carriage, said carriage being movable by said link between 10 an operative position in the vertical portion 01' said slot when the valve is opened and an inoperative position in the horizontal portion of said slot when the valve is closed.

2. The combination according to claim 1 further provided with a curb ring disposed above said basket, the thickness gauge when in its inoperative position being disposed above said curb ring.

BRADLEY G. COX.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,224,136 Caskey May 1, 1917 1,906,767 Roberts May 2, 1933 1,921,446 Andrews et al Aug. 8, 1933 2,090,373 Neuman Aug. 17, 1937 2,130,864 Steps Sept. 20, 1938 2,328,394 Neuman Aug. 31, 1943 2,337,817 Hertrich Dec. 28, 1943 2,467,023 Foster Apr. 12, 1949

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