US177109A - Improvement in vacuum-pans - Google Patents

Description

J. -FAIRBURN VAcUUasm-MN. N.177,109. Patented may 9,1876.

N.PETERS, PHOTO-LITHOGRAPHER. WASHINGTON, D C4 vTo all whom it may concern:

PATENT OFFICE` .JOHNOFAIRBURR OF UPTON STATION, ASSIGNOR OF ONE-HALF HIS RIGHT TO `.ISAAC PLUME, WILSON, OF MONTREAL, CANADA.

IMPROVEMENT IN VACUUM-FANS.

Specification forming part of LetterslPatent No. l 77,109, dated May 9, 1876; application filed March 9,1876.

Be it known that l, JOHN lFAIRBURN, of Upton Station, in the county of Bagot, Province of Quebec, in the Dominion of Canada, haveinvented certain new and useful Improvements in Vacuum-Pans, ot'which I hereby declare the following specification, when taken in combination with the accompanying drawing, to be a full, clear, and exact description.

The objects of my improved. vacuum-pan are, first., to overcome excessive foaming, which is'so usual in globular vacuum-pans', and which retards the evaporation of liquids bein g boiled; and, second, to increase and benetit the circulating of the liquids being evaporated. As is well known, liquor from barks, while heilig' boiled down for the extract, occasions a great deal ot' trouble and loss by foaming, which is due, in a great measure, to the imperfect inanner ot' forming the pans in which they are boiled. j

My vacuum-pan, like that ot' ordinary pans, is constructed in three sections, bolted together, as will be seen in the accompanying drawing, in which- Figure l represents a sectional view ot' the p'an embodying my invention; a'nd Fig. 2 represents a ground plan ot' the heating-surface, showing the relative. position of the drums and steam-coil.

The three separate sections of my pan are indicated by the letters B, E, and F, they beingjoined where the lines a and l) intersect. These different sections are bolted together. Thesteam-coil is indicated at O, and, thedrums H having an increasing vertical depth from the circumference to the center, and which are located in the lower section F, the same as in ordinaryy globular vacuum pans, the coils O are supplied with live steam, which enters at the side ofthe pan, and the steam, after passing through these coils, exhausts at the bottom. The steam-drums H take in live steam at the bottom, and exhaust at the same. The

steam drum or drums are circular boxes inserted with vertical tubes, the transverse section of which shows a rectilinear gure. It has a superiority over all other applications for heating-surfaces, for in a -hollow helical band or coil, with or without increasing vertical depth, the liquor is very apt to foam when the live steam `is first let into' the coil, as the liquor'boils in a great rolling body, and Vwill often foam out ot' the pan, when evaporation commences, on account ofthe sudden vacuum formed at the lirst condensation of the vapor;

-which cannot be fully appreciated except by one engaged in superintending a vacuunrpan where so much loss is occasioned by the liquid foaming up and escapinginto the vapor-pipe A.

The most important portion of myimprovement relates to the construction of the middle l belt or section E, which, instead of being contracted, so as to form perfectly perpendicular sides, similar to an ordinary vacuum-pan, is made to bulge out at its center, and more contracted at the topA than vat the bottom. At the top ot' section E I provide a projecting lip, which is curved inward to prevent` priming, so

that the liquor, instead ot priming up through the pipe A, will be thrown inward. I also contract the top section or dome B to the size of the bottom portion oi' the vapor-pipe A, which is secured to it at this point. l

It will readily be seen that, as the curves ot' the sections B and E are struck from a dil'erent radius, and that they are both contracted at the top, they, together with the bottom or lower section F oi' `the pan, form, as it were, a pau of an ununif'orm ellipse-like shape, which I claim to be very favorable to the circulation, and, consequently, rapid evaporation.l

Now, as rapid evaporation is the essentialA virtue ot' a vacuum-pan, and to produce which it is necessary to havea good' circulation, which can only be effected by having the liquid bash down in the center when boiling, the most natural way for liquid to boilis upon the sides and down in the center. Now, by reference to the drawings, it will be seen that by constructing the pan as I propose to do, the sides, being continuous almost with the bottom, instead ,of rising abruptly, assist in bashing the liquid toward the 'center of the pan, causing it to take the course indicated by the arrows G. It is believed thaftlthe a1'- rangement and shape of this pan so facilitate A:the heating and circulation its Huid mn` exhaust-Steam piiie 'K and L enter in the same relative positions asthose of ordinary vaeunnr pans, so I will not go into details, as my ilpprovements do notrelate to 'the arrangentien t 'of the parte and necessary appendages of the l pan as to its forin- My improved pan may also be need for oondeneinn milk, in whioh ease the d rnrns willj not reqnire to be so deeniend the vacuum-ran will require to besomewhatsmelller than that used for making extract. The great object in oontlensng milk is .to

doit at a low temperature, so as to keep 3a scum or skin from formi-ngen the surface; hence, it will be found thatfimproved pau will condense milk far better than any other, Aas `it will evaporate milk tolerably quick at 100o Fahrenheit. i

Having :thus yfully described my invention, what l claim as nem-and desire to secure by Letters Patent, is-' A l. A vacuum-pan constructed with a dome, B, -iniddle ntion Qrbelt E, curving inward from a point near its vertical center toward its ends, in combination withthe lower section F, the whole .founding van in `shape .similar to an ellipse whose larger axis is vertical.

2. 'lhe inwardly-curved projecting lip, situated on the inside top'edge ofthe middle belt or Section E, to prevent pnimng, substantial I .y as speeiiedl 3, The circular and vertioallytnbular A:steam (imm or drnins LI H,navingxan `inercia-,ning ve... depth, from eirenmfeenee 1to centen In ,testinonythet I elailn the foregoing as my invention l have my nignatnrein the presenee of two Witnesses.

Jenn mineures.

Witnesses:

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