US2452207A - Fluid pressure operated curb sirup separator - Google Patents

Description

Oct. 26, 1948.y c. A. oLcoTT 2,452,207

v FLUID PRESSURE OPERATED CURB SIRUP SEPARATOR y Filed Feb. 1, 1944 2 sheets-sheet 1 Oct. 26, 1948.

c. A. oLcoTTy FLUID PRESSURE OPERATED CURB SIRUP SEPARATOR Filed Feb. l, 1944 2 sheets-sheet 2 IIHI' JNVENTOR. 244m E5 Mc-077 BY l a 2,452,2.ojv

connection with the accompanying drawings forming a part thereof, in which:

Fig. 1 shows in partial cross section a centrifuge incorporating a curb syrup classifier employing uid pressure in accordance with the invention; and

Figs. 2 to 5, inclusive, show details of various modifications of the arrangement shown in Fig. 1.

Referring more specificallyv to the drawings, Fig. 1 shows, byl way of example for illustrative purposes, a fluid pressure-operated curb syrup separator for centrifugal machines used in the manufacture of sugar. The centrifugal machine comprises the usual basket I with perforated side walls, the basket being suspended at the lower end of a vertical drive shaft II within a suitable housing or casing. In the centrifuging operation, the molasses and 'lwash uids successively introduced into the basket are cast off through the lateralperforations while the crystalline sugar builds or wallsup on the interior facefof the basket. '@The'centrifuged yfluidsfare thrownagainst the interior casing wall or curb I2 `and flow down its" face for collection in and discharge from one or another of a plurality of concentric annular troughs or gutters I3 and i4. These gutters are separated and partially bounded by a vertical annular wall or partition I5. "At its upper extremity the partition I5 is causedtoslopeoutwardly and upwardly to form :y

a flange I6 'which'fextends almost to the inner surface of the curb wallA I2, leaving a very narrow annular gap or opening H between the membersV I6 and I2. This gap affords a passageway for curb Syrups destined for the outer trough I4. p-

Wash'iiuid is provided by means of the pipe i8 terminating in an opening IB. A valve is providedto control the :dow of the wash fluid.

In the Varrangement shown in Fig. 1, the openingflI isfmade as small as possible. It -may be one eighth inch or even lessbecausethe whirling action of the air and syrup inside the `curb I2 Vwill cause any syrup, especially thin wash syrup, to flow Vthrough this'opening into gutter I4 ratherthan to flow into gutter I3 (provided there is nothing toprevent such flow). To `control this action,` means isprovided tor force a suitable gas or vaporfthrough conduit 2| into gutter I4, This means may comprise a low pressure steam pipe 22, for example, but other gases or vapors may be used instead of steain, if desired. The outlet 2,3 of gutter I4 is trapped at itslowerend 24, as by having it discharge into trough in which the level of the syrup is valways maintained at a point 26 whichmis considerably aboveY the end 24 so that the fluid being forced through conduit '2l into the gutter I4 will of necessity have to pass out through the annular opening 'I'I. The amount and pressure 'of the fluid being forced into the gutter I4 V,is made sufficient to maintain the uid pressure within gi'itterl'iigher,A than the air pressure in the curb'IZ plus a small pressure caused by the weight ofmolasses ,(syrup) which would accumulate at the opening I'I. Bythis means,v.the molasses cannot flow through the opening II frito the gutter while iiuid from the pipe 22 is passing into the gutter I4. The level 2'I of the liguidin the outlet 24 is, of course, lower than the level `26.` When steam is used as the fluid-pressure ysupplying means, heat and humidity are also supplied by the steamto the syrup to facilitate its now.' .Y Conduit Y2I is provided withavalvel or other suitablecontrol meansgso that the flow` of fluid from the source 22 to the gutter I4, increasing the pressure therein, may be cut off whenever it is desired to allow the wash syrup to flow into the gutter I4. Normally the green syrup is more viscous than the wash syrup so that the small opening I'I would normally not permit more than a small amount of green syrup to flow into gutter I4 even if the increase in fiuid pressure were not: provided. y,The increased pressure inaccordancewith this vinventionis sufficient to ,entirely prevent such flow. The pressure supplied by the Y pipe 22 is preferably slightly higher than the air pressure inside the curb I2 at the opening I'I. This pressure will vary according to the dimensions of the centrifugal basket and curb and the speed of the centrifugal. In practice, the pressure is readily measured by a gauge tapped in the side of the curb I2 above the opening I'I and the pressure in the source 22 is adjusted to give a slightly higher pressure Within the gutter I4, which pressurel is similarly measured. "The arrangement'of Fig. 1 operates as follows: `When` the centrifugal machine is started by suitable automatic or manual means, the valve 28 is turned (substantially simultaneously with the starting) to the open or on position to'permit the steam` vfrom the source 22 to flow into the outer gutter I4. The green syrup being, spun off the sugar grains by the rotation of the basket Ill passes through the small apertures in the basket and strikes the curb I2 and ows down it toward the gutters I4 and I3, the flow being facilitated by the heat andyhumidity provided by the steam. Due to the increased pressure in the lgutter I4 caused by the steam, the syrup does not pass through theY `opening I'l into this gutter but passes instead to the gutter I3. After asuitable time interval the'wash water for other fluid in the pipe I8 is turnedY on by moving valve 20 f and, after a very short time interval suflicient to wash the green syrup off the curbing wall, the valve 28 is turned to the off position. Closing this valve not only cuts olf the steam pressure from the gutter I4 but also has the effect of causingr a partial vacuum within the gutter I4 due tothe steam condensing. Thus the pressure in the curb I2 outside the gutter I4 is at least as great as (and usually greater than) the pressure within and the wash syrup flows by gravity into this gutter. `After another suitable time interval,the length of which is determined by thetime necessary towash the sugar to the desired color and purity without unnecessary wasting of sugar by needless washingthe wash fluid is out oif and the `centrifugal allowed 'to rotate a little while longer to dry the` sugar. After the drying period,

the centrifugal is braked and unloaded. While the various steps of (1) starting the centrifugal and turning the valve 28 Vtothe fon position, (2) turning on the wash fluid in the pipe I8 by moving the valve 20 to its on position, (3) turning the valve 28 tothe fo'fff position, (4)-cutting off the wash fluid by `moving the valve 2B to its off position, and (5) the stopping of the centrifugal by cuttingvoff the powerand applying the. brake may be performed at the proper time by manual means, preferably an automatic controller 29, ofv any ksuitable type, is provided to cause the actuation .of `the various elements at the proper times. The controller 29 for sim- .plicity in the drawinghas been represented as a box with various mechanical or electrical lconnections 30, 3|, 32 and 33V (represented schemati-g callyasdashed lines) leading therefrom tothe valvevZB, to thevalve 20' inthe wash fluid-pipe I8, to the'driving means for the centrifugal and tothe brakek ymechanism therefor, respectively. By way of example, an automatic controller of the type shown in Patent1,94'7,6'79 issued Feb. 20, 1934, to R. A. Steps can be used toscause the various steps described above vto be performed atthe. .proper time.

. lf the opening Il extends all the way around the curb I2, a considerable .amount of air is required to maintain the desired pressure in gutter I 4.` In 'order to reduce the amount of air required, spaced plugs 'or interrupters 34 are providedv in ortabove the annular opening Il to divide this opening into a large number of circumferentiall-y spaced openings. The'members 34 are held in positionby any'suitable means and may be integral with thecurb I2. As shown in Figs. 2 and 3, which 'are enlarged partial cross-section views., these interrupters 34 reduce by about 50% that portion of the opening VIl through which air can pass. Each of the plugs or interrupters 34 preferably v.converges upwardly to a peak or ridge, .as shown in Fig. 2, so that molasses flowing down the wail of the curb i2 is directed to the openings between the Iinte'rrupters.

" lFig. 4 shows a modification wherein the outlet from the gutter I'd is taken from the same pipe 35 which feeds the fluid (steam, for example) to the gutter 1I4. The outlet pipe '36 is trapped at its lower end 3l, as by lhaving it discharge into trough 33 in which the level is always maintained at a point 39 which is considerably above the end 31 so that the fluid being forced through conduit 35 will have to pass into the gutter I4 and out through the opening Il. The level lll of the liquid 'in the pipe 36 is. of course, lower than the level `39, this being due to the fluid pressure. The arrangement of Fig. '4 has the advantage over than of Fig. 1 in that only one opening `(35) into the lgutter I4 lis required rather than the two (2`I and 23.) -in the arrangement of Fig. l.

After the green syrup has been spun off and caused to flow into the gutter I3 and the wash water is being applied by the pipe i8, thus causing the wash syrup to be spun off, it is sometimes desirable to encourage its flow into the gutter i4' bymore positive means than by merely removing the increased fluid pressure from fthe source 212. This can lbe accomplished by applying a negative pressure or suction to the pipe 35 by any suitable means. By way of example, a pump dl (seeFi'g. 5) can be provided to make the pressure in the gutter I4 less than that in the curb l2 when itis desired to have the wash syrup 'flow into the gutter I4. A valve 42 canbe provided in th'e pipe connection 4'3 leading to the pipe 35 and this valve can be controlled with the valve 28 in the pipe 2I by Ia member 44 in such a way that as the valve 28 is closed the valve 42 is opened, and vice versa. The oper-ation of the valves 28 and 42 can be controlled by hand or by any suitable timing means "such as the automatic controller 2'9 described above in connection with the arrangement of Fig. 1. Valve 28 is open, causing the fluid pressure in gutter I4 to rise. while green syrup is being spun off, valve 42 being closed during this interval. Valve '2'8 is closed and valve 412z is fopen during the time the wash Isyrup destined ifor the gutter I3 is bei-ng spun off, thus causing the lowering of 4the pressure in the gutter I4 to below atmospheric pressure by the action of the pump (negative pressure means) 4I. Fig. 5 also shows an air blower 45 for forcing air at a pressure comparable to that of the steam in the pipe 2| into the pipe 35 at the same time that the `steam is vnot used and only `the lair .from the blower 45 is utilizedA to increase the pressure in thelgutter I4. If the steam is not used, the air from the blower 45 be heated and/or liuniidhl fied by any suitablemeans` (not shown) if desired. Except for the changes mentioned above, the

operation'of the arrangement shown in Fig. 5 Lisv like vthat described above in connection .with Fig.. l. It should be noted that duringr the suc-v tion part of the cycle the level lof `the syrup in the outlet pipe 36 rises to a Vlevel `49 (show-n by dash lines in Fig. -59 Awhich is higher than either of the levels 39 and 40.

The principle of providing an increased iuid pressure inside the -gutter I4 lcan also be used advantageously with the mechanical types Aof syrup separators `commonly used. This separator, as explained above, may develop leaks due to various causes, and supplying -a fluid at yincreased pressure prevents these leaks from admitting green syrupinto v4the vwash -syrup-gutter M.

Various changes and 'modifications other lthan those specifically mentioned above may be made without ldeparting from the spirit of the inven tion, the scope of which is indicated by the appended claims. In the claims, the term fluid ifs intended to be broad enough to cover amixture of two or more fluids as well as ra single fluid.

What is claimed -isz l. The method of directing two liquids which successively flow through the same space in dif` ferent time intervals into different ones of two containers, said containers being provided with directing means,- which directing means and containers are so locatedwitlh respect to each other and to said space that any liquid in said space normally iiows therefrom vint-o the rst container only, which comprises applying a fluid pressure irl-the first container, during the time interval that the first of said yliquids is flowing through said space, which is sufficiently `high to deny said rst liquid access to said first container and rto act in cooperation with lsaid directing means to cause said rst fluid to flow into the second container, and thereafter reducing the fluid pressure, during the time interval that the second of said liquids is flowing through 'said space, `to a value which is suiciently lo-w so that liquid access to said first container is no 'longer denied, whereby said second liquid flows into said rst container.

2. The 'method of separating green syrup rfrom wash syrup in a sugar centrifugal comprising a rotatable mesh basket, a Acontainer therefor provided with twoannular gutters, one outside ofthe other, for collecting the syrups, the two gutters` being so located with respect to the rest of the container that allthe syrup normally flows `into said outer gutter only, and Vmeans between -'the' gutters for directing syrup .toward the-inner gutter whenever the flow vthereof into the outer gute ter is blocked, which comprises the steps of` applying a fluid pressure in .the outer gutter during that portion of the centrifuging cycle that the green syrup is being spun otfwh'ich is su'fliciently high to prevent the green syrup from entering said outer gutter, whereby the green syrup is directed by said directing means into the inner gutter, and then reducing the fluid pressure in said outer'gutter to a pressure vwhich is suioiently low to allow syrup to, flow therein during atleasta part of that portion ofthe centrifiiging cycle that the lwash syrup is being spun orf;

`3. In combination, a containerfor liquids comprising inner and outer annular troughs at the base thereof, centrifugal means above said troughs for causing liquid to flow in said container toward said troughs, said troughsgbeing so positioned with respectto said liquid flow that the liquid normally flows into ,the outertrough only, directing meansbetween said troughs adapted to, direct the liquid into `the inner trough, land means for applying fluid. pressurev inthe, outer Ytrough to such an; extent that liquid from said centrifugal means isprevented from flowing into the outer trough, the liquid thereby being directed into said Vinner trough by said directing means. i

4. The combination of elements as in claim 3 in which said fluid-pressure `applying' means comprises means for conducting steamat a pressure abovethat of the ambient pressure of said c'on.

tainer to the interior of said outer trough.

A5. The combination of. elements as in claim Bin which said fluid-pressure applying means comprises means for conductinguair at a-pressure above thatof the ambient pressure of said container to the interioro said, outer trough.

. 6.*The combination of elements as in claim 3 iii-which said fluid-pressureapp-lying means com- A prisesmeans for conducting a mixture of steam and air at --a pressure above that of the ambient pressure of said container tothe interior of said outer trough.

7. In combination, a centrifugal machine cornprising a rotatable basket, a casing enclosing said basket and comprising a curband inner and outerconcentric gutters within said lcasing and below said curb having respective top openings for receiving curb fluids flung off from said basket against said curb during the centriuging process,` said top openings being so located with respect to said cuubthat all the curb fluids normally flow into said outer gutter only, the opening in said outer gutter being veryV narrow but suflicient to permit the passage of fluid therethrough ifthe opening is not blocked, directing means ibe tween the gutters adapted to direct the curb lluids into said inner gutter whenever said opening in theV outer gutter is blocked, and means for applying fluid pressure in said outer gutter to such an extent that the opening in said outer gutter is blocked to the passage of curb iiuid, said fluid thereby being directed into said inner gutter by saiddirecting means.

8. In combination, a container for liquids comprising inner and outer annular troughs at the base thereof centrifugal means above said troughs for lcausing liquid tovnow in said container toward saidtroughs'said troughs being so positioned with respect to said liquid flow that the liquid normally flows into the outer trough only, directing means between said troughs adapted to direct the liquid irito the inner trough, means for applying fluid pressure in theouter trough to such an extent that` liquid from said centrifugal means is preventedirom flowing into the outer trough, the liquid thereb'ry being Ydirected intol said inner trough by said directing means, and means for applying. simultaneously with said fluid pressure, heat and humidity to said outer gutter to facilitate the flow of liquidin said container.

during desired time intervals only fluid pres iii 5:: d'. Thecombination'. of elements as in -ijclai'm 28 inpwhich said last-mentioned means comprisesl means forv conductingV to saidfouter trough steam at al pressure. above the ambient pressure off said outer trough. i I? 10..-.,In'V a :centrifugal machine, a centrifugal basket with a perforate wall, ar surroundingcasf. ing comprising a curb for directing downwardly liquids centrifuged from said basket, inner,l and outer-annular troughs below said basket for receiving curb liquids, said troughs being separated a common annular partition and being so positioned with respect to said curb that all the curb liquids normally flow into the outer trough only, a directing member at the top of said partition extending almost to the inner wall of said casing to greatly restrict the opening in said outer trough and positioned to direct cunb liquids intosaid inner trough whenever the opening in said outer trough is blocked, and means for applying uid pressure in the outer trough to such an extent that the opening therein is blocked and curb liq-` uids are thereby prevented from flowing into the outer trough, whereby the liquids are directed into said inner trough by said directing member.

11. The combination of elements as in claim 10 in further `combination with a multiplicity of spaced members for stopping up portions of said opening in the outer trough to further restrict the effective area of said opening.

12. The combination of elements as in claim 10 in further combination with a multiplicity of spaced mem-bers for stopping up portions of said opening in the outer trough to further restrict the eiective area of said opening, at least some of said spaced members being tapered upwardly to a peak so as to direct curb liquids striking them downwardly into the outer trough.

13. In combination, a container for liquids comprising inner and outer annular troughs at the base thereof, centrifugal means above said troughs for causing liquid to llow in said container1 toward said troughs, said troughs being so positioned with respect to said liquid ow that the liquid normally flows into the outer trough only, directing means between said troughs adapted to direct the liquid into the inner trough, means for applying sure in the outer trough to such an extent that liquid from said centrifugal means is prevented from flowing into the outer trough during said intervals, the liquid thereby'being directed into said inner trough by said directing means, and means for applying, in place of said nist-mentioned fluid pressure and during time intervals which are different from said first-mentioned time intervals, liuid pressure in said outer trough which is below the normal pressure in said container.

CHARLES A. OLCOTT. Y

REFERENCES CITED The following references are of record in thel le of this patent: i

UNITED sTATEs PATENTS Steps Feb. 20, 1934-

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