US548986A - hewitt - Google Patents

Description

l (No Model.)

3 Sheets-Sheet 1. P..C. HEWITT.

\ EVAPORATOR.

No. 548,986. Patented 0011.29, 1895.

W/TNESSES.' 5 /NVE/VTOH:

(No Model.) 3 Sheets-Sheet 2.

P. C. HBWITT. EVAPORATOR.

' m0548986 Patented oct.29,1895.

m5190991.) 3 sheets-sheet s.

' P. G. HEWITT.

'EVAPDRATOIL No. 548,986, Patented 001;. 29, 1895.

I W/TNSSES.'

@Miren diri-fires PETER COOPER HEWITT, OF NEW YORK, N. Y.

EvAPosATos.

. SPECIFICATION forming part of Letters Patent No. 548,986, dated ctober 29,1895.

Applicatlonriiled Tuly 2, 1892. Serial No. $38,762.v (No mariah).

To all, whom t may concern:

Be it known that l, PETER COOPER HEWITT, of New York city, in the county and State of New York, have invented a new and Improved Evaporator, of which the following is a specitication, reference being had to the annexed drawings, forming a part thereof, in which Figure l is a vertical section of my improved evaporator, taken on line :c a: in Fig.' 2. Fig. 2is a horizontal section taken on line y y in Fig. l. Fig. section of a 'modified form, and Fig. 4 is a horizont-al section taken on line e z in Fig. 3.

Similar letters of reference indicate corresponding parts in all the views.

In the evaporation of liquids for the pur-VA pose of concentrating them or in the generation of steam for motive power or heat the circulation' of the liquid is commonly secured by taking advantage ofthe difference in speciiic gravity due to different temperatures of different portions of the liquid. As the difference in density is slight, the circulation produced in .this way is necessarily slow, permitting bubbles of vapor to adhere to the walls of the chamber or of the tube in which they are formed andl tohinder the rapid transmission of heat from the said walls to the body of the liquid, and the liquid itself not being a good conductor of heat, except by convection, the amount of liquid evaporated the liquid is the object oil in a given time bya given amount of surface is limited by the amount of heatvthe liquid will take up from the walls.

To facilitate the evaporation of liquids by accelerating their circulation and by securing a more effective contact of the liquid and heating-surface by bringing. more liquid in contact with the heating-surface and also the rapid separation of the vapor formed from my invention.

My invention comprise an apparatus for rapidly evaporating liquidsi as Will be hereinafter fully describethand pointed out in the claims. r

The separating-chamber A in the present case consists of a single casting furnished with a cylindrical cavty a and with passages b, which are tangentiafl to the cylindrical cavity a. Thesaid passages are curved inwardly in the casting, as shown in Fig. 2. The lower part of the cylindrical Icavity a is conical, and

3 is a vertical transverse` toward which tho conical sides of the-cavity incline. In the chamber A above bottom thereof and'aehort'distance below the openings of the 'passages b is vhorizontal partition d, andin the tion adjoining the wall of the y formed segmental ports-e, and to the under side of the horizontal partition d are attached Win gs e', which ar'e located between the curved in the casting is formed a central opening@- the conical' arranged a said parti cavity are,

ports and projectdownwardly, the wings serv. .l Q

ing to check the rotary :notion of the liquid passing through 'the ports, Above the openings of the passages b the chamber A is contracted and furnished with an invlardlyprojecting flange yforming an annular groove y, which communicates with and 'forms part of the liquid-discharge openingsrat one side of the chamber. The inner edge of the inf wardly-projecting ang'e f is. arranged in-a position intermediate between perpendicular lines drawn from the walls of the dischargeopening z' and perpendicular lines drawn through the nner portions of the portee, so

that the inner wall of the revolving'Tiquid will lie between the perpendicular lines passing through the inner portions of the ports e, and ,thus be withdrawn from the inner wall of the discharge opening.r The dischargeopeningz' is concentric with the chamber-and is fontheesca-pe Of. VfpOP- The chamber A is j at the top for receiving the vapor-pipe and with a perforated flange k at the bottom. To the said perforated fiange k and in contact provided with a'tiange" with the bottom of the chamberA is secured a plate B, provided witha central opening c', coinciding with the opening o 'of the cavity c, and withopenings b", coinciding with lthe passages b of the chamber c; In the central opening c of the plate B is screwed-a pipe'C,

screwed the pipes D. To the titted the perforated plates E, E', which are each provided with a flange Z. The said plates E E are oppostely arranged with respect to each other and provided with 'glands ma m' n on their outer surfaces, which! permit of the movement of either or both'of the plates E E or of the pipes D C in the plates without causing leakage or straining the parte.

' Surrounding the pipes C D and between pipes C D are.

roc

the plates E E is placed a cylindrical shell F, provided at its ends with anges o, which are secured to the flanges Z of the plates E E by means of bolts or otherwise. To one side of the shell F, preferably above the center thereof, is secured a collar p, into which is screwed a steamsupply pipe G, and to the opposite side of the shell, or in any convenient position, is secured a collar q, into which is screwed the discharge-pipe H, which passes through the shell F. A jacketl surrounds the portion of the pipe C inclosed by the shell F, leaving an intervening space r', which prei vents the pipe C from being heated tothe same degree as the pipes D. The pipe C isr screwed into a hollow base J, communicating with the space s in the said base, and the pipes D enter the hollow base J and commu- -nicate with the space s, the said pipes D beingsurrounded by glands n2. A supply-pipe K communicates with the interior s of the hollow base J.

The operation of my improved evaporator is as follows: The liquid to be evaporated is introduced into the apparatus through the pipe K, and in the present case the heat necessary to drivewoff the vapor is supplied by steam introduced into the shell F through the pipe G. The pipe C, being protected by the jacket I, is not heated to the same degree as the pipes D. The liquid contained in the pipes D gives off bubbles of vapor, thus ren dering the columns contained by the pipesD non-homogeneous-that is to say, the said 'columns are composed partly 'oi liquid, and

partly of vapor-while vaporization is partly or wholly prevented in the central tube C. In consequence of the difference in density in the columns contained by the pipes C D the column contained in the pipe C descends, forcing upward the columns contained by the pipes D, causing the said pipes to discharge through the tangential passages b into the separating-chamber A. The jets which are thus made to enter the chamber impinge upon the walls of the chamber, and thus produce a rapid rotary motion in'the liquid contained by the chamber, which carries the heavier portions of the liquid toward the wall of the chamber, while the vapor goes to the center of the chamber. As the capacity of the chamber is limited when liquid is'supplied, one portion of the liquid is discharged over the in wardly-projecting fiangef, the main portion being continuously discharged independently of the feed through the ports e into the lower part of the chamber a, thence into the pipe C, which returns -it to the hollow base J, whence it again rises through the pipes D. This operation is made continuous, and the concentrated liquid which is discharged over the flange f and through the discharge-pipe h is replaced by fresh liquid introduced into the hollow base through the pipe K. The/rapid upward movement of the liquid through the pipes D frees the walls of the pipes from all adhering bubbles of vapor, thereby maintaining a perfect contact of the constantly-changing liquid with the Walls of the pipes, thus insuring the rapid transmission of heat and great rapidity of action. Moreover, the portion of liquid which is returned to the central tube C possesses a downward velocity due to the ascending velocity ofthe column in the pipes D D and its transformation into centrifugal force in the chamber mand this downward velocity increases the edect of the in the pipe C and adds to the rapidity of the circulation.

In the modification shown in Figs. 3 and 4 'f the pipes D', in which the liquid is heated, communicate with a hollow base, as in the other case, and discharge into a receiver t, which is furnished with an outlet pipe to, terminating in a multiple discharge-nozzle L, placed within the separating-chamber A', the

weight of the liquid said multiple discharge-nozzle being provided with an enlarged annular opening v,in which are placed oblique Wings tu, which cause the jets of liquid to issue ina practically tangential direction, so as to produce a rotary motion of the liqu'id iu the chamber A. The separation of the liquid from the vapor is el? fected in the manner before described, and the vapor escapes through the opening fi', while the concentrated liquid escapes through the pipe 7L. The liquid is returned to the hollow base through the external return-pipes C',

My method and apparatus'can also be used for separating a mixed liquid or solution by the removal of one portion in the form of vapoigyleaving another portion which is not vaporized. The absolute pressure, whether more or less than the atmospheric pressure under which my apparatus may be operated,

docs not affect the Working of my invention, which is applicable to a Wide range of pressures.

I wish to be understood as including in my invention under the term evaporator, as used in the foregoing specification and the following claims, such apparatus as steamgenerators, vacuum-pans, dsc., used to vaporize liquids wholly or partly for any purpose whatever.

By the term tangential jet or nozzle, as used in my specification and claims, I mean a nozzle arranged with reference to the separating-chamber, so that the jet discharged from the nozzle into the separating-chamber will strike the wall of the chamber at such an angle as to impart a rotarymotion to theliquid discharged and to maintain rotary motion in the liquid in the separating-chamber.

My apparatus will work successfully Whether the liquid is discharged into the separating-chamber from without inward, asV

Vbe the case in the apparatus illustrated in Fi g.

3, as either method will produce the required rotary motion"in the separating-chamber. in thev first instance the particles of vapor Awould -be forced inward toward the center of the chamber by the pressure of the liquid.

. In the second case the liquid would be pro- 1 by Letters Patent-4 veffected bythe motion of the liquid, a separatin g chamber, the said separating chamber being furnished with a vapor outlet, one or more liquor outlets at the bottom thereof, and a liquor overow arranged between lines pass'- ing through the vapor outlet'and return liquor outlet, for the purpose of maintaining the inner or free surface of the body of liquor between the vapor outlet and the return'liquor outlet, substantially as specified.

3. In an evaporator, the combination with the heating and return tubes, of aseparating chamber provided with, tangential nozzles, and having onel or more discharge ports each,

for vapor, liquor, and the return liquor, the

said discharge ports being arranged in diierent planes, substantially as specified.

4. An evaporator, comprising a separating .bfamber, aseries of heating tubes communi-- eating with the separating chamber Ithrough tangential nozzles, a heating drum inclosing the tubes, and one or more protected return pipes insulated from the heat, for conveying the liquid from the separating chamber to the lower end of the heating tubes, substantially as specified. of

5. In an evaporator, the combination with the heating and return'tubes, of a separating chamber providedwith tangential nozzles, and having one or more discharge ports each for vapor, for the liquid, and for the return liquid, substantially as specified.

6. In au evaporator, as'eries of evaporating f tubes, and an inclosing shell provided with y heads through which the tubes'pass, the said heads being separated from the joints of the evaporating tubes with the separating chamber and hollow base, leaving portions of each tube exposed between the separating chamber'and heating drum, and hollow base and heating drum, to avoid leakage of steam into the vacuum space, st ystantially as specified. v7. An evaporator, comprising a separating ,chamben a series of heating tubes communi-

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