US1287650A - Evaporator. - Google Patents

Description

N. DEERR.

EVAPORAIOR. APPLICATION FILED AUQ. $6. 1911.

Patented Dec-17, 1918.

2 SHEETS-SHEET 1- N. DEERR.

EVAPORATOR.

APPLICATION FILED AUG.I6,19I7. 1,287,650, Patented Dec. 17, 1918. 2 SHEETSSHEET 2- Big. 2

CONDENS/l TE,

WITNESSES Y l/VVEN 701a.

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NOEL DEERE, OF BROOKLYN, NEW YORK EvAPoRAToR.

, Specification of Letters Patent.. Pate ted D 17 1918 Application filed August 16, 1917. Serial No. 186,573. f

the like. [he objects of my invention are first, to separate the incondensable gases from the steam or vapors used to effect evaporation in a more natural and eflicient manner than has been accomplished in the past by other evaporators of record; second, to drain the condensate from the calandria of the evaporator in a simpler and more ellicient manner than has been accomplished in the past; third, to obtain a greater heating surface per unit of space, without adding any detrimental hydrostatic pressure to the boiling liquids, thancan be obtained by the usual cylindrical bodies of otherevaporators using vertical tubes; fourth, to provide a possible heretofore.

uniform distribution of the liquid entering an effect over the heating surface and a uniformly distributed withdrawal of the liquid leaving an effect; fifth, to design atype of evaporator which embodies the simplest type of construction; necessitates the making of the least number'of patterns, many of which may also be used for an apparatus of any size; minimizes the amount-0f machine work required; and makes an apparatus less expensive .toconstruct than known evaporators and at the same time more efficient in operation; sixth, to provide a downtake or passage for the circulation of the boiling mass in such a suitable location and of such a'shape that a more rapid circulation can "be obtained than has been The invention consists in the novel parts, constructions, arrangements, combinations and improvements herein shown and described.

The accompanying drawings herein referred to and constituting apart hereof, illustrate one embodiment of the invention,

and together with the description serve to explain the principles thereof.

Of the drawings p V Figure 1 is a front elevation of a multiple effect evaporator; in this particular instance a triple effect evaporator;.

Fig. 2 is a combination end elevation of one cell and a sectional elevation through said cell taken on the line 2 2, Figs. 3 and 4:; F g. 3 is a sectional plan view on the line 33 Figs. 1 and 2;

Fig. 4' is a sectional plan view takenat 4-4, Figs. 1 and 2'.

Fig. 5 is a section through the calandria of a cell showing the means adopted to obtain the uniform distribution of liquid entering an effect and uniform withdrawal of 7 the liquid leaving an effect as applied to apparatus of large size and larger than that indicated in Figs. 1, 2, 3 and 4.

Similar letters ,refer to similar parts throughout the several views.

In the exemplified embodiment of the accompanying drawings,,A, B and C, are cells of a multiple effect evaporator in which A is the first cell and receives steam into its calandria through the openings d. B is the second cell, and the liquid therein is caused to boil solely by the heat of the vapors arising from the boiling liquid in the 1st cell, A. Similarly the vapors arising from cell B flow through pipe 6 to the calandria f and cause the liquid of cell C to boil in turn.

A high vacuum is maintained in the vapor space of cell C; a vacuum of less degree in the vapor space of cell B and calandria of cell C; a, slight degree of vacuum only is required in the vapor space of cell A and the calandria of cell B; steam pressure of about 1 pound per square inch or more 1s usually supplied to the calandria of cell A.

a It is due to the difference in the vacuum that one cell has over the other that enables thevapors of one cell to boil the liquid in the next cell in series, for it is a natural law that the boiling point of a liquid decreases as the vacuum under which ebullition occurs increases.

The foregoing explanation of the, operation of a multiple effect evaporator was thought to be desirable for it will aid in better. understanding the nature of my'invention. No claim for originality however 7 below the tube-sheets. v

The sheets are perforated and into each .hole an endofawertieahtube is 'rolled.

These sheets and tubes together form a part of the apparatus known/asp eala'ndria. Steam is admitted-to the-space between'the tubes -The lnaterial to be evaporated is contained within the tubes and above and In what is known as :the liorizont al sub- ;inergedtube evaporatorfl the tube sheets are ertical and the tubes run; horizontally. In

this type, the steam is boutained wi't'hi n the tubes; and the material gt'of-be evaporated between the tube sheets and-on th e outside of thetubes -Bothdesigns have their advantages in the ver ic t appar he tubes eanibe mechanically;cleaned In osi- 1 tion, while in the horizontal-type they lave to be removed fl'om :the apparatus; in the iyertioa l apparatus a amore ef iective circulation can be given to the material undeugoi ng ey aporatioi-i, than is the casein the horizontal tube apparatus. K YVith respect. to the elimination of the undesirable incondensable ,gasesand the condensed water, my invention vequals-or surpasses the "horizontal submerged tube apparatus.

, Asffbefore-statedneither the vertical sub- ;merged tube apparatus nor the -horizontal submerged tube apparatus combine; these qualities:

Referr ing rnore in detailto therembodi- :n ent of-the accompanying drawings, :the cell or effect ispreferablysubstantially rectangu- -;lar considered in horizontal crosssection, and 1s provided in ltS- bottom' part with a cala-ndria and a circulatory system for the juice or ,other solution to be'concentrated.

In the present preferred en'i'bod-iment, the steam or other heating vapor has-astraightaway passage way or ,conduit from its. inlet to =th e:=outlets,for the condensate andt'he non-condensable vapors so constructed and arranged that :no .part of the rapidly rushing body of steam or other hea'ting vapor interferes with or backs up against an other ,part thereo f, seas to negativeo'r interfere with a freeand l nij'for1n .,distribution and travel of the heating vapor; but onthe foo'ir trary such a. free and. uni forrn flow o'f -th'e heating yapors is secured, that, im'iforioa' and efiicient yheat ing and circulatioii of. the liquid under concentr'a;1 ;ion is al ays, maintained. con ctio with the mean t effecting located at one end "thereof.

such uniform heating and circulation through and about thecalandria of the liquid underconcentration, simple and eflicient 'ineans'are provided fofremoving the con- "d'ensate and the incondensable gases, all said (I 11163118'ilfOiiplatlfigi together and conducing to the general desirable results and advantages set forth.

- In Fig. 3 the calandria is divided into two straigh't away steam spaces, withta duwntake nre rtendingalong substantially the entire length of'the calandria. Through each steam space extend the liquid heating and conducting .p-ipes m, the don"ntake a receivvthe flow from the pipes m on bothysides thereof. In Fig; 5 the cal'andria is divid ed into three steam spaces or straight-away, chambers, with two downtakes n, one be tween-each two steam spacesor, chambers. Each steam space'jor chamber has an intake or supply .p'iple d for the heating'yapor In the embodied form,

downwardly from .the en'd w ere thel heat- I the, tundra co np'risesa top'pl'ate land a bottom -Z ,"-the lattei "being 'jpreferably flat; and inclined ing vapor enters Ytojfthe end where are locited the-outlets for the condensate'and for the 'in'condensable x "afpor's, both the top and bottom plates fbei'ng ,pi efeifably and staehed toltheside walls of the cel Th eis "thus rovided a unidirectional gonduit "for,

theheating vapor, which is prc ferably rectangula'r'iiicros's section A r v The vertically arranged tubes m are mounted in the top and bottom" platesl and Z and open into the cell both at theirtops and bottoms and constitute thefehieffheating lngazgns and the upward channels {for the cirunderg'o'ing concentration.

The cluster oftubes in is p'referab arr:inge'd substantially along and throughout the extent of the conduit, spaced apar sufli- 'cien'tly to permit adequate passage space for .the current'of heat i 'ngx 'apor, Passageways 0 arelefti'n the group oftubesm so located ,a1'1ddisposed with respect to the inlet and,

path of travel of the heating Vapor. asto' causeequa'l distribution of the heating vapors 'thro'u'ghou'tlhe tubesi'jv'ef and the entire heating area, I

f Suitable downwardly directing means for the-circulating liquid undergoing eonceiitra:

tion is provided in such relation :to. the m .as to insure a uniform, unimpeded and non-conflioting flow and circulation from the tops f th tubes back to the"-b ot'tom thereof. As embodied, adown'take passage n extends substantially I the entire length of "the tube cluster, 'a nd 'i's disposed longitudipally of the dire tion-v.01": th heating. vapor flow, the vertically and longitudinally'disposed walls of this intake connecting with the top plate Z a d b'dttomplat'e' Z? The downtake thus body construction and arrangement of the means for supplying and directing the heating vapor, and for withdrawing the condensate and the incondensable gases, the inlet into the calandria for the heating vapor is indicated by d, and it is located at one end 'of the vconduit or chamber just described.

At the opposite end of the conduit or chamher, which is likewise remote fromthe vapor inlet d are'the exits or outlets for the incondensable gases, and in accordance with one feature of the invention there is provided a relatively large number of spaced apart exit or exhausting orifices for the gases, preferably located relatively closely together and disposed or located both vertically and horizon'tally throughout the entire end of the heating vapor chamber which is opposite the inlet d.

As embodied, there are a plurality of spaced apart, vertically disposed pipes 3 arranged entirely across said opposite end of the chamber. These pipes 31 are provided at intervals throughout their length with gas admitting orifices 2. The pipes y at their upper ends empty into a header 9, this header in turn emptying through a pipe 9 into the pipe or conduit e which conducts the vapors produced from the boiling liquid from the cell into the next succeeding cell or effect. This pipe g may be supplied with a regulating valve 9 Means are provided by the invention for conducting away the condensate from the heating vapor chamber, and as embodied, a plurality of draining pipes h open downwardly from the floor or bottom sheet Z of the calandria, the pipes being spaced apart across the end of the heating vapor chamber, as will be seen from Figs. 1 and 2. These draining pipes empty into a manifold or header 7L arranged therebenea-th and drainin g in turn into a pipe k The bottom plate Z of the calandria, constituting the floor of the heating vapor conduit, it will be recalled is preferably a flat plate, sloping gently from the end of the conduit having the vapor inlet (13 toward and to the end of the conduit along which are arranged the series of draining pipes h for-the condensate. r

In the operation of the heating system just described, the steam or other heating vapor enters-at the inlet J at a high velocity, a customary velocity being about 4000 feet per minute, and rushes along the straightaway and uni-directional conduit or chamber, parts of the vapor current impinging on and surrounding immediately the pipes at and parts ofthe current rushing along the passages 0 and first impinging on and surrounding pipes relatively remotely located from the inlet d. Owing to the lower temperature of the pipes m, the heating vapors are condensed all along and throughout the chamber and fall or flow to the floor thereof, and the condensate runs rapidly to the draining outlets h by reason both of the slope of the floor and the onrush of the vapor.

- The incondcnsable gases do not, as is often stated, Separate into gases which are either heavier or lighter than the incoming vapors, the lighter gas to conveniently float to the top tube sheet of a calandria where it would be anIeasy matter to draw it off and get rid of it the other gas to fall to the lower tube sheet to be similarly drawn oil.

It has been found in practice that the great velocity oi' the vapor flow or current in the interior of a calandria keeps the gases completely mixed so that any drawing oil of the said gases as above described and based on their difference in specific gravity is a fallacy and cannot be obtained. Therefore the importance of my invention is realized when itis stated that perforations e are made at regular intervals in the outlet tubes y throughout their entire length. The perforations inithe gas outlet tubes as above described make that portion of the calandria where the volumes of incondensable gases accumulate an area of multitudinous openings distributed both vertically and horizontally at spaced intervals throughout the entire rear end of the heating vapor chamber or conduit, these openings at all levels drawing directly in the mixed incondensable gases which have been driven forward by V the heating vapor current. V I

Referringto the means for supplying and conducting away the liquid undergoing concentration, and in connection therewith certain parts relating to the internal circulation thereof, the calandria in a cell is usually in multiplicate of the parts already described, that is there are one or more downtakes n provided with a heating vapor chamber or conduit on each side thereof. In Figs. 1, 3 andai a central downtake nis shown with a heating vapor chamber on each side thereof, and in Fig. 5 two down takes at are shown I with a heating vapor chamber therebetween and one on the outside of each downtake.

The inlet into thecell for the liqu d to be concentrated, as embodied, comprises a pipe or pipes, w extending horizontally beneath the calandria, and provided on the upper side thereof, and elsewhere as desired, with a plurality of spaced exit orifices w for disextends along: underneaththe heating or i swan-1 *ehaifnber." The" hefiting' wiper fund the 'epor" eonduit or cheiiilie'n p t In accordzincefivith one feature of the inof the uibes'm be the eorresp eieg liettifi 've iti'dn, a defleating pldtet isermin'ged-bv r and, asl-ong th exit pipe v'fand being-prefembly a little ien er than thedowntake n.

The plate 4; is pre'ferebly lei-nee with '1; iongitudinal top central edge sfthesides oifthe plate curving outwardly and downwardly the down'te'ke n being thereby deflected equally to either side and beneath the two ings ware providedfthrough the deflecting plate 25 to permit apart of the downcoming liquid to 'pa ss'throu h aiid' into the exit pipe 0, and longitudinalg disposed -spaces w are provided alongor beneath the bottom edges of the deflecting plate "2}; likewise efiording passages for the liquid to th'epi'pe "0, espeeielly'inthe event of the openings u through plate it becoming clogged. Thusthe're is insured an outlet to the exit pipe 9) atpraeti'celly noekpend'iture 'or'ive'ste of "energy of the circulating liquids.

j The exit pipe or pipes viof'one can meffeet ereconnected by a piipe'h to thesupply pipes wofthe next succe'e 11g @611; to conduct the partiiil'lyeoiieen tratecl liquid thereinto to subject it to the next stage in the process of eoncentra'tion. in e Well-knownmanner. A regulating Valve 2')? is referably provided to *cmitr'ol the 4 ne 1 of the liquid I between the successive cells or efl'ect's' L The circilldtioh iiifthecell, stai ting by m of example eta point midway in thetubes m.

is upward; due to the'heiiti n'gof thetubes'hy v the Stea in or other heating l Vapor.

emergingfrom the tops oft-the tubes-m the hot b'utfa'lready cooling and denser {liquid flo wsecross toward the top ofthe' 'do'w'ntake l $1 5 flQW 6f the being parallel 1 tifiaii canveyging, 31d therefore an b'ac'k fpies'su're and sta nant span 'and une u areir- Qcul'ittion are avoided. As the flowing liquid tecom suens'er by the release, ofthe yaporat the surface fund by -cooling, it deseends *j'tiliroughfthe downtake and is deflected ftoheath the -tube's m the-Camden, and ib'y reason fof the upw'ei'dffiow "through t lie tubes,

" thejliqliidii's'es tli ereiiito and so-'pa sse -again e reegh the enciueu n eyclejust described.

the i). for the Delft suc c'eedings tep in "the co'tieeritietionheszilreadybeen described.

The pipe fin'a nifold carrying the "hot {liquids entering the Gen '1 have. located at "the-most logical position, forsincethe liquids run fioi n cell "to ce ll and the "first cell is at nf hig hei --te11r er tm than 'thesece d, the

1 "end liigher' tlizih the third, etcI,it renews t the liquid entering the next succeedin l in series after it "has been boiled in the eced'ingcell under a greater pressure'thli'n oljttinsin'seid succeeding cell, some of the "fliquid' will flash into "vapor and since the location of entrance pipe :0 is Immediately helo'i'u mesh-eating tubeclustersfm, it follows that this Vapor formed "by the unsung from the liquids leaving the preceding cell will help boil the liquids in the 'cel'l where the JThe "t'i'iiisference -the hezitfet the um- "tion I nave'uescfi beu is not "the may ad- "fiintage found howeve'n v Bubbles of steam ind vupeicreated bythe flashingint o mper 'just described, rising upwa'rdly and being db'liged to .floW through the tubes will have ftligefl'edt of aiding the circulation in the ffvess'el; for in their natural course to the top the-liquid, the bubbles drive along the liquid in thetubes. I

I have purposely made the inlet pipe :2? *perforitted 'with a nu-friber of smell outlets.

" The adyent-age gainedis that the indenting "liquid from the preceding cell is gclivided and distributed into a, number of ets and consequently the cir'c'ulii'tion is inade inoi'e hnifoi-in than ebuld he done "otherwise.

Aslioiifn in Figs}, 2, 3, end 4, thereiii'e indicated two inlet pipes for the incoming juice, one pipe 1) for the withdrawal of the j'uiee and one'doivntdke or circulating Well I '71 loe'a te'd over the pipe withdimfing the 'i imd'one deflecting plate is. In ap t l' erate Size not more than about eight-feet square th s means will be uifii nt [to attain a proper distribution and circulation of the majte'rial undergoingevaporation. In apparatus of larger size I will employ three '01- Inore pipes to introduce and distribute the incoming liquid, two or more pipes to "effect a uniform tv'ithdrau al of the 'l-iqii'i'd, two or more downtekes or cireulati'ng wells and two 01' more deflecting plates. All

the tubes. P a a Using this fact as a basis, I haveaccord these will be symmetrically arranged with respect to each other and substantially as indicated in Fig.5; I a.

The liquid being evaporated is hottest while itis passing through the tube clustersand coldest when it is farthest away from ingly located the outlet for the liquids in the farthermost location from the hot tubes and at a point whererelatively cold liquor only is passing.

Again when taking samples of material undergoing evaporation from different parts in the same cell of an evaporator of the circular submerged tube type, it has been observed that the samples are-often of difler'en't density.

Seeking the cause of this inequality, I have come to the conclusion that either some parts of the calandria of the cell must receive a greater amount of steam or vapor than other parts or that the draw-oil pipes are not'correctly located causingthe liquid in certain parts of the apparatus to become* stagnated or nearly so and to be very deficient in respect to circulation.

This efi'ect is not only very detrimental to the rate of evaporation but also because it results in some portion of the liquid undergoing evaporation being exposed for an undue length of time to the high temperature necessary to effect evaporation.

On the basis therefore that the proper location of the draw off pipes is very essential to the proper working of an evaporator, I have accordingly provided numerous inlet connections regularly spaced on the exit manifold '12 throughout its entire length across the bottom of the cell and directly below the down-take n, so that all of the liquid in the evaporator must pass in close proximity to some one of the exit connections.

The assurance that the liquids will be drawn ofi' regularly is obtainedand long continued presence of any portion of the material in the apparatus is avoided.

The bottom tube plate Z is arranged with a fall in the direction of the flow of steam. In my invention this is accomplished in the very simplest manner by using a plain fiat tube plate Z and assembling one end lower than the other.

The cylindrical standard efi'ect is handicapped in the respect that it cannot adopt this arrangement except with great mechanical diificulty.

Forging the lower tube sheet so that it will form a truncated cone with an altitude of only several inches is generally resorted to, and since it i always desirable to have all tubes exactly the same length, the necessity of forging the upper tube sheet as well as the lower is easily understood.

pacity of the circular submerged tube evaporatoris not-easily enlarged, except possibly by lengthening the tubes which automatically increases the hydrostatic pressure on the liquids which in turn lowers the eificiency of the apparatus. Y Y

In the apparatus as above described, enlargement of the cells is easily accomplished simply by adding additional banksof tubes and inserting and adding new sections of exterior shell. In this manner the circulation of the liquid isnot impaired in the slightest degree although tw or more downtakes will be required.

In points of constructionand ease and inexpensiveness of machine work, the square or rectangular shaped evaporator in plan section far excels the circular section apparatus. V

In the square or rectangular evaporator all joints will be 90 degrees which insures ease in machining, simplicity in patterns and makes a'mininium number "of patterns ment of the liquid being evaporated. This save-all is not shown on the accompanying drawings nor recorded in the claims at the end of thi specification.

Having thus described my invention and not wishing to limit myself to the exact specific construction therein disclosed, andknowing that many modifications of my invention can be made and at the same time be within its scope, I therefore claim 1. An evaporator including in combination a substantially horizontal straightaway chamber confining and directing the flow of the inrushing vapors in a single right-line direction, vertical fluid conducting tubes passing through said chambers, a common down-take passage extending along said chamber substantially for its entire length and dividing it into two parts, and receiving the flow from both sets of tubes, a supply pipe extending along beneath the tubes in one chamber, a supply pipe extending along beneath the tubes in the other chamber, and a common exit pipe extending along beneath the downtake.

2. An evaporator including in combina-- tion a substantially horizontal straightaway chamber confining and directing the flow of the inrushing vapors in a single ght-li e dine i n, art ca ui nduc ing tubes pa ng through aidi hamb rs, a.

mmon n-tak p sag e ten ing 'qn s id chamber ub t mt ly 9.:v t enti e en h diiri ling t mt We, pmt s, nd;- reqeiving the flgw from b91111 sets; of; tubgg, a,

supply pipe extending along bellfiikth thg tubes nq echa b a supply pipe ext d-- ing along bgneath thg tubgs -in the; other chamber, and; a ,co nlmqn gx it pipg. extendifig aulong benggth the dpwnt k, a hQl ZODtflHY n d dfiflefiton iI Q TP Q betw n the aka d. ex pip d op nings past he. d c Qr for i i ig ngfinidr t9 he, ex t. plpe.

n eyapolzamr. inc u ing n comb naio sub tant y I' ZQH J': st aight: w y hamb r Qn u ng a d direszting, t q ow of the mlshing' apmnsv n 'a ingle,

right-line direction, vertical fluid conducia g ubes. p ssing, l i i ugh said: cham ers,

21 comm lrdo nitake: pa y age tmdif ngi alpng said; chambersubstantially fol? its en tire length and" diyiding it into two parts and feceiving the How fnom. both sets of? tubeg gnd; means vgijzhin and it bhemean and Q ltom 0i sa d st a ghtaway chambens- 01:

am ng. may the. conidensatss and me ns;

Within and at the rear and upper pql tions.

of said: chamb n for ca rying. away the; noncondensable vapors, r An eyapo zin r. mc udmg 1n cmnbma:

t ayels, plurality of-flll dx cQnduc ing pipe passing; thelx hh t ugh, and; a fluipl: supply P p f mnlng i lQllg; beneath. the calandrgm,

Qc ed to: ha e a c uht-ericulznent flow-

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