US1558957A - Vacuum pan - Google Patents

Description

C. WHITE VACUUM PAN Filed March 15, 1925 2 Sheets-Sheet 1.

0 l0 fzo Oct. 1925. c. WHITE VACUUM PAN Filed 1925 2 Sheets-Shot 2 Patented Oct. 27, 1925. p PATENT, ,oiaraict;

CLARENCE WHITE, 01? SAN FRANCISCO, CALIEQRNIA.

.zvacqmvi PAN.

Application filed -March 18, 1925. SeriahNo. 16,463.

Toa ZZ whom z'tmag concem: 1 During the evaporation tovgrain, .0ut-, Be it- ,known that 1, (hin -Enos SR err e, a ned abo e, ib =Of m-p r ance to;-P event CltlZ8l1,,Of the United States, residingat theflowering ofithe liquid leveltoytheupper Francisco, in theconnty. of San Fran- Sl-H'face Ofthe heater gelenientiinasinuch; as O cisco -and StateofCalit ia have invented qareme izi g, burning ofhtheesugarbatch, new and useful Improvements in Nacutun t kesplaoe immediately, as so onias theheater ,ans, or which the tollow-ing is a specificm is vuncovered or not properly snbinenged. i n 7 I I @ne of the objects .of-the inventioniis to This inventionrelat-es to evaporating ap- P i ca d v t m;p nhavingsuch paratus and ,pertains -particularly to img n al P n in erior construc ion provementszin calandriayaeunin pans used t a eh st gr reentmay ib8;p. t 0I1el ii -that stage ofsugarmanufacture in which l w rm s na 'of thepan a d'yGt-be sugar liquor is largely converted to grain ufli n y l g 1 uncti n SatiSfa tEOriIy- ,;Heret0iore, in calandr a vacuum pans-e it lathe operation of vacuum pans, and in hasgbeell: 0 13 3 0 'PFQ large P the graining steps particularly, pan is llw ui 'C m P0 I t.ofthe'pan-botli d ith li f -&ppfOXin:lat81y.4 0 torn, nsna llyleading toan ontlet'pip'e. Such per t t d 60pm cent sugar,;th construction nsually places .vthe lowerrnost pan being filled to any desired height. P 9 h P1111 farvbelowthe heating elestea n is turned into 7 {111 internal heater ment and often necessitates the installation withinthe pan to boil the liquid content, of 1 211 p peller in.the1ower- =part and as ;the liquor thickens after a short f t P t id in'the ciroulationofthe eriod, a gpain fgugggr' begins to fgnnand l1ql1ld. the objectsMonths-present by this time the original batch of liquor has 111V611t-10I1 v1S 0 provide for improved B'Clf- 90 been reduced in volume until it harelycovers ll, n vQ 8 iS, effected by means offan the internal heating element. iUp'to ;this pw rd y p yectmgbulge .extending'irom point the grain of su ig n t f ll grown, the floor or the pan centrally upwardly so that ;is, not of a commercial size, though asto: provide a central coresuhstantially the probably the number ofv grains in the origiheight of, the walls-ofthe,encirclingheating 85 nal hatch ,isthe same'as in the complete element. Th scentral; core serves'thei dual fl strike as the fini h d b t h i commonly tt'unction of assisting the circulation and retei'med. lVhcn the .crystals have reached ducingby its own size the Volume of the their proper size it will usually be found total amountof liquid requirec'i'to submerge that the pan is quite well'tilled. the heating member. This latterjfeature is 'Fora grain of Sdgtthfiygrow it m t b part cularly important because it makes it f d b th li or, that is, avsugar solupossible to heat a relatively small batch of tioirwhich will provide supplemental,sugar sugar lQUOl and toiconcentrate it likewise t i l t b ild 011 t th rai a d down to a comparatively small-amountwithpermit an grow to theproper size. The t da ger of un ve ing the i g 010-. 5 ()yig'inal b t h hi h h be b ht t want and possibly ruining by burning that a te of concentration where a barely per partlcular batch of sugar. ceptible grain is formed is augmentedfrom One of the objects of the inventionis to time to time as the treatment progresses by provide an upwardly projecting central core drinks 1 of fresh liquor, (additional liquor the side walls of which slope inthe-sanie introduced) which are in turn concentrated general directionas theencirclingfwallsfot to a point where the sugar is given up and the heating member and in the samegeneral attaches itself to' thegrains vforined'in the direction as the pipes through the heating original hatch. it will be seen that with ineinben The invention contemplates the each drink the grain increases in size and use or an annular heater located adjacent. the volume of the batch is increased. Fithe lower floor of the pan and which is nally, after many drinks, the last or p culiarin that the upperand lowerqwalls which has beenhronght to the proper conslope centrally downwardly, thus providing centration the grain is of the desired size an inner centrahwell wall the upper opening and the pan is full. The batch is finished of which is smaller thanthe loweropening. and thepan is emptied, after which the Theeirculating pipes adapted topconduct operation repeated. 7 I fluid through the heater, are inclinedfzup wardly and centrally with the result that the tubes are installed substantially at right angles or nearly so, to the upper and lower walls of the heating element, which feature lends ease for installing them by expanding them in the upper and lower sheets of the heater element.

Another feature of the invention relates to the provision of an annular steam channel around the outer circulating pipes and just within the shell of the steam belt portion of the vacuum pan. This feature makes it possible for the heating steam to pass freely around the entire assembly of circulating tubes and to move inwardly to the central point where it is drawn off at the lowermost point of the heating element.

Another feature of the invention is the provision of a central core which is open at both ends to the atmosphere and which projects from the central lower point of the pan floor throughout the height of the pan and is open to the space above the pan. This central relatively cool core promotes the circulation movement of the liquor within the pan. The central core provides also for the use of a control rod, operable from above the pan, which projects downwardly through the central core to open or close the drain valves or outlet valves which are opened whenever the strike is complete.

The above and other details and advan tages will be described and claimed in the following specification and claims and illustrated in the accompanying drawings, in which:

Figure 1 shows in elevation, partly in vertical section and partly broken away, a calandria vacuum pan embodying the features of this invention and in which the central core is illustrated as having sloping walls, tapered upwardly substantially the height of the heater element; and

Figure 2 is a view of a modification in which the central core and the wall of the well of the heater element are substantially vertical, the central core being substantially the height of the heating element and being continued in the upper reduced tube which communicates with the space above the vacuum pan.

Like reference characters in each of the figures denote like parts.

Referring in detail to the several views of the drawings. 1 is the cylindrical shell of the vacuum pan having the interior liquor cham- 7 her 2. The lower portion of the cylindrical shell has an outwardly flared bulge with an encircling wall 1 which accommodates the heater portion of the apparatus as will be described. The bottom floor of the vacuum pan is indicated at 1, extending with a sloping surface downwardly and centrally. The roof of the vacuum pan extends from the encircling cylindrical shell with an upwardly and centrally inclined surface 1. The topmost cover of the roof portions is indicated at the curved surface 1 which caps an upper cylindrical portion 1 In this cylindrical portion 1 is a tortuous traplike outlet passageway formed by an upwardly projecting extension 1 leading from the upper edge'of the roof 1 and terminating close to the inner under surface of the top cap P. A complen'lentary downwardly projecting battle member 1' hangs from the under surface of the cap 1 and encircles member l with the result that vapors led oil from the vacuum pan in order to escape must go over the top of the battle member I thence downwardly between 1 and 1 and thence upwardly again to escape out through discharge opening 1 The heater portion at the bottom of the vacuum pan provides the bulge mentioned above as having the outer encircling wall 1*. Just within this wall 1 is an annular space 3 which extends completely around the interior surface of the wall 1" and is provided as a result of the inclination of the circulating tubes 4 through which latter the sugar liq uor passes from the under surface of the heater element through the heater to the upper surface of the heater element. The heater element includes a top plate 5, also complementary lower plate 5, both of which are of the general shape of truncated cones having their smaller ends downward. 5 and 5" are positioned parallel to each other and thus spaced apart by the distance of a connecting well wall 5 which connects with the inner marginal edge of the upper and lower members. As shown in Fig. 1 the heater element is peculiar in that the upper opening is smaller than the lower opening and the well wall 5 thus slopes centrally upwardly. In Fig. 1 also it will be noticed that the circulating tubes at are inclined obliquely with respect to the outer vertical cylindrical walls 1 but are substantially parallel with the well wall 5 In this position the circulating pipes 4 have almost a right angle fit in the upper plate 5 and the lower plate 5 of the heater element which makes it possible to flare over and fasten with comparative ease the opposite ends of the individual pipes into the upper and lower plates of the heating element. The central well wall 5 provides the well space 6. Steam for heating the heater member is led in through the openings 7 through the wall 1, and spent steam is led off at the lowermost point of the heater through the pipe 8 which projects downwardly through the floor of the vacuum pan.

Material for treatment in the vacuum pan is supplied or drawn in tl'irough the pipe 9.

The central displacement core or bulge in the bottom of the pan is indicated at 10 as raving a fluid-tight connection with the margin of an opening in the floor l The -'tra11-acorc1l10-: and .closing' outlet openings formed in 'thezlower portion of :Zthe .Wall of the core At thGrbOttOIIl of the vacuum -panz-is a, catchall in :thelshape of Y a funnell-ike 1 member 12;- through-which the material of" :the' fstriket. ,is i discharged downwardly into a pipe or discharge spent 13;

:"Operati-ng means for controlling :theoutlet'ivalves of the pan is. provided by a rod 14;

which extends downwardly 7 from; above the -p'an,through the rlength oi the tube-10Rto a point adjacent the bottom of the panrwhere it; branches With shortextensio-ns 15. The

of the rod as-indicatedat 16 andin turn the lower endsot' the extensions are piv- -otally connected at '17 -to their respective valves 11. Thecl'osed position of the valves 11. is indicated in dottedzlines, the'solid linesshowing the valves in their, open position. The rod 14: isjournalled in bearing .mkamberslt? which extend across :the bore of the core 10 and aid in centeringthe rod 14' within the tube 10 and Within the core 10.

Power means for moving the rod '14; is providedby a cylinder and a piston mounted on the top cap of the -vacuum-.:cl1am her. The ;cylinder 18 is a small extension projecting upwardly and having it apiston 19 mounted on the upper end of therod 14 and "by which the rod isactuated. pipe 20 communicates through the cylinder wall "18 tofthe uppersurface of the piston and a pipe 21 at the lower-end of the cylinder' 18 communicates withfthei under sidey-of the plstoni Steam or compressed all applied alternatclyas the case may requiretothe pipes 20 and 21 will provide suflicientpower to open or close the foot valves 11.

.fThe samecontrol apparatus isillustrated in Fig. 2. The apparatus of Fig; 2difi'ers from that of Fig. l in that the central iWll wall is vertical and parallellingthe.cylin drical sides of the central core. In this viewalso the circulating tubes 4 do not meet the upper and lower. sloping surfacesof-the heater-at right angles, which, arrangement results in. a construction somewhat more tedious fto -manufabture th fll'l; the arrange; ment 5 shown '111 Fig; 1. An important: feature of: advantage ,in botlnformslofgheater element resides ;in the sloping upper surface ofthe lie-aterwhereby the; flow 6 of heated liquidemerjging. from the several tubes, 4 is directedcentrallya and downwardly to; the

relatiyely.;,cool. core, thence to;be tied down through the well ,6 and =re-'cinculated through the heatedztubes.

In the operation of the apparatusavac uumiswereatedin the pan usually by: means of a vacuumpump, and the required amount of liquor.to;-be concentrated is drawn'into the panzthrough .the pipe 9. Such amount when boiled downto grain or to crystahis foundvby experience vin sugar factories ito give thebest results when it is 25 percent-or per-centotthe total finished contents of the pan, but. under no conditions should the initialcharge ,i'ail to submergethe heating element. v

Steam is admitted through the pipe 7 into thechamber 3 around the tubes and thus it heats the exterior v0t each of the, pipes 4, causing the heated liquid Within" the pipes to boil up through the pipes and toi flowdownwardly in the well.;space 6, and. along side of the center core. The relative coolness of the wall of the core promotes this particular circulation. Vapor arising from the boiling liquor .passes upwardly and through the upper trap to a condenser,-,not shown, and usually'attached tojthe upper vaporoutlet.

Additional liquor is added and concentrated until the pan is filled toa prescribed level, after which the steam is shut off, the

.vacuum brokemland the contents discharged. From theforegoing it will-,bejobservedthat the apparatus provides a construction permitting. aaminimum: amount of liquor to submerge-the heating-element; also-that the heating element and its cooperating core are of such a size and shape flS'tO- offer the least resistance'to the natural circulation ofthe boilingcontents ofthe pan The core has eliminated to a large extent the deep pockets beneaththe heating-element. I

,v Further, it willt-be-noted-that by-virtue of the; displacement core 10-beingrelatively coolandr in communication with theatmospheretat the-bottomofthe -pa-n,- and extend ing a considerable distance up into, thebody of the vacuumpan, a vnatural thermo-siphon efiectiscreated-aiding the circulation of the contents; downwardly throughqthewvell and up through-thetubes.

wardly and centrally, aheateneleinnt With- 111 the casing; and adjacent ebut'spacedi above the floor thereof and having a central open space extending upwardly therethrough and constituting a well having an upper and a lower opening with a closed side wall, and an upwardly extending core projecting from the casing floor lengthwise of said well and with its upper end adjacent the top of said well, said core constituting a displacement member whereby the volume of liquid within the well is reduced by the space occupied by the core.

2. In a vacuum pan for treating sugar solutions, a casing with the floor sloping down wardly and centrally, a heater element within the casing and adjacent but spaced above the floor thereof and having a central open space extending upwardly therethrough and constituting a well having an upper and a lower opening with a continuous side wall, said upper opening being smaller than the lower opening and said side wall sloping outwardly toward its lower end, and an upwardly extending core projecting from the casing floor and into said well, and having the shape ota cone, the axis of which extends lengthwise of the height of the well and the apex oi which is substantially adjacent the top of said well.

3. In a vacuum pan for treating sugar solutions, a casing with the floor sloping downwardly and centrally, a heater element within the casing and adjacent but spaced above the floor thereof and having a central open space extending upwardly therethrough and constituting a well which is smaller at the top than at the bottom and which has an enclosing continuous side wall, said heater element including a plurality of inclined tubes arranged around said well and sloping toward a-conu'non central axial line at the top so that their upper ends project toward each other and providing for communication between the space above and the space beneath said heater element, and an upwardly extending portion of the casing floor projecting as a core into said well, and within the center of said heating element, the upwardly projecting core'constituting a displacement member positioned in said well whereby the fluid content necessary to fill the height of the well is reduced by the volume displaced by that portion of the core within the well, and whereby the circulation of material over the surface of said core substantially parallels the movement in the inclined tubes.

4. in a vacuum pan for treating sugar solutions, a casing with the floor sloping clownwardly and centrally, a heater element within the casing and adjacent but spaced above the floor thereof and having a central open space extending upwardly therethrough and constituting a well, the side wall of which well is approximately the shape of the truncated side wall of a cone with the smaller end at the top, said heater element including a plurality of inclined tubes arranged around said well and sloping toward a common central axial line at the top so that their upper ends project toward each other and providing for communication between the space above and the space beneath said heater element, and an upwardly extending port-ion of the casing floor projecting as a cone into said well and within the center of said heating element and with its apex adjacent the top of said well, the upwardly projecting cone constituting a displacement member positioned in said well whereby the fluid content necessary to fill the height of the well is reduced by the volume displaced by that portion of the cone within the well.

in. a calandria vacuum pan for treating sugar solutions, a casing having a floor slopingdownwardlyfand centrally, a heater element extending annularly around the interior of the casingan'd adjacent but spaced above the floor thereof and" providing a central open space upwardly through the heater element, an upwardly extending portion of the casing floor projecting as a core into said central open space and within the center of said heating element, and a discharge outlet with a closure therefor 10- cated-in the side of said upwardly extending core and next adjacent said floor and atthe lowermost point thereof. 7

6. In a vacuum pan for treating sugar solutions, a casing with the floor sloping downwardly and centrally, a heater element within the casing and adjacent but spaced above the floor thereof and having a central open space extending upwarlly therethrough and constituting a well having an upper and a lower, opening with a closed side wall, and a tubular displacement member extending upwardly as a continuation from the casing floor and the floor being open beneath said displacement member, axially lengthwise and upwardly as a central core within said well and of considerable area in cross section at a substantial-distance up in the well, and constituting means whereby the space for liquid within the well walls is lessened by the space occupied by the central core, all points on the axial side of said core being in open communication with the exterior of said pan through the open bottom of said floor beneath said core.

7. In a vacuum pan for treating sugar solutions, a casing with the floor sloping downwardly and centrally, a heater element within the casing and adjacent. but spaced above the floor thereof and having a central open space extending upwardly therethrough and constituting a well having an upper and a lower opening with a closed side wall, and a tubular displacement member extending as a continuation from the casing floor, axially lengthwise and upwardly as a central core within said well, and

projecting beyond the heater element and throughout the height of said pan and having its opposite ends open, whereby circulation of air is permitted centrally through the tubular member and through the height of the liquid undergoing concentration in the pan.

8. In a vacuum pan for treating sugar solutions, a casing with the floor sloping downwardly and centrally, a heater element within the casing and adjacent but spaced above the floor thereof and having a cent'al open space-extending upwardly therethrough and constituting a Well having an upper and a lower opening with a closed side wall, and a tubular displacement member extending as a continuation from the easing floor, axially lengthwise and upwardly as a central core within said well, and projeeting beyond the heater element and throughout the height of said pan, said tubular member being relatively large in cross section throughout the height of the well and thereafter and above the well being relatively small.

9. In a vacuum pan for treating sugar solutions, a casing having a closed floor and closed roof, a tubular member extending through the height of the casing and having its lower end and its upper end open to the atmosphere, valve means located at the lower end of said casing for controlling the discharge of material from the casing actuating means for controlling said valve means and located on the exterior of said casing, and power transmitting means extending lengthwise of said-tubular member and within said tubular member, and connected to both said valve means and said actuating means.

10. In a vacuum pan for treating sugar solutions, a casing having a floor and a closed roof, a tubular displacement member connected at its lower end to the floor of the casing and at its upper end with the roof, both ends being open to atmospheric pressure, and an expansion member located in the length of said tubular member whereby influence of temperature changes in the tubular member and in the casing will not change the total length of the tubular member Within the pan.

In testimony whereof I afiix my signature.

CLARENCE WHITE.

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