US1884726A - Evaporator - Google Patents

Description

Oct. 25, 1932. J KERMER 1,884,726

EVAPORATOR Filed May 27, 1929 1 valuables.

Patented Oct. 25, 1932 UNITED STATES PATENT OFFICE MARTIN J. KERMER, F BUFFALO, NEW YORK, ASSIGN'OR TO BUFFALO FOUNDRY & MACHINE COMPANY, OF BUFFALO, NEW YORK, A CORPORATION CF NEW YORK EVAPORATOR Application filed May 27,

This invention relates to an evaporator which is more particularly designed for evaporating milk although the same can also be used for removing or reducing the water content from the solids of other liquid mixtures.

It is one of the objects of this invention to provide an apparatus of this character which is comparatively simple in construction and therefore permits of making the same of more expensive metals, such as nickel and stainless steel which ordinarily is too eX- pensive for use in constructing evaporators in accordance with the designs heretofore known. a i j P Another object of this invention is to so organize the evaporator'that the entrainment of solids in the vapor drawn off is reduced to a minimum, thereby avoiding waste of the Further objects of this invention are to provide means whereby the evaporator or heating tubes can be thoroughlycleaned and also readily and conveniently replaced when necessary, andalso to provide simple and efficient means for reliably supporting the evaporator in its operative position.

In the accompanying drawing:

Figure 1 is a vertical longitudinal section of an evaporator embodying my improvements.

Figure 2 is a fragmentary verticaltransverse section of the same taken on line 2, 2

Fig. 1.

Figure 3 is a horizontal section taken on line 3, 3 Fig. 1 looking downwardly.

Figure is a horizontal sectiontaken on line 4, 4t Flg. 1 looking upwardly.

Figure 5 1s a fragmentary vertical section on an enlarged scale showing the manner of welding together the parts of the dome and securing the evaporator tubes in the flue sheet of the dome by welding.

In the following description similar characters of reference indicate corresponding parts in the several figures of the drawing.

The numeral represents the dome of the evaporator which may be variously constructed but as shown in the drawing the same preferably consists of an upright cylin- 1929. Serial No. 366,143.

drical sheet metal body 11, an upwardly dished crown 12 secured at its peripheral edge to the upper edge of the sheet metal body 11 by means of a welded joint 13, and a sheet metal flue sheet 14 forming the bottom of the dome and secured adjacent to its marginal edge to the lower edge of the sheet metal wall 11 by means of a welded joint 15.

Projecting downwardly from the central part of the dome top and diametrically across the upper part of the side wall is an upright main bathe 16 preferably made of sheet metal and terminating at its lower edge at a distance from the bottom or flue sheet 14: of the dome so as to form a horizontal passage between the inlet chamber 17 within this dome on the front side of the balile 16 and the outlet chamber 18 within this dome in rear of the baiiie plate. The upper part of the outlet chamber 18 is provided with a vapor outlet 19 through which the vapors are withdrawn from the apparatus and which is pref-v erably connected with an exhausting device of any suitable character so as to create a. vacuum whereby these vapors are forcibly withdrawn from the outlet chamber of the dome.

The numeral 20 represents a plurality of upright evaporator or heating tubes which are arranged to form a cluster or bundle uni erneath the front part of the dome and which open at their upper ends into the lower end of the inlet chamber 17 of the dome in front of the baffle plate 16, this being preferably accomplished by extending the upper end of each of these tubes into an opening 21 (see Fig. 5) in the flue sheet 14 and se curing these parts together by a welded joint 22, as shown in Figs. 1 and 5, or by expanding these tubes in said openings or securing the same therein in any other suitable manner.

The lower ends of these evaporator tubes are likewise secured by welded oints 28, eX- pansion or otherwise, in openings formed in the lower flue sheet 24, which forms the top of a manifold or liquid chamber 25 arranged below the cluster of evaporator tubes. These tubes are heated on their exterior by a heating medium of any suitable character, but

of the tubes and is secured at itsiupper edgeto the underside of the upper flue sheet 14, and a comparatively long lower section 29 surrounding the lowerpart ofthe tubes and connected at its upper end with the lower end of the short chest section 28, while its lower end is connected with the lower flue sheet 24. Y

The upper short steam chest section 28 is arranged eccentrically within an outer sup porting ring 30 of larger diameter which 25i latter is secured at its upper edge to the marginal part of the underside ofthe upper flue. sheet 14 and is preferably made int'egrally of cast metal with the small inner supporting ring 28 which constitutes theupper'sectionof the steam chest. These inner and outer rings 28 and 30 therefore-form a convenient and reliabl'emeans for supporting'the evaporator at a point adjacent to the upper end thereof on the beams, pedestals or: other sustainihgpant of the building.

To permit of' thus supporting the evaporator, the outer large ring 30 is provided at different points of its periphery with laterally projecting brackets or'feet 31 which are adapted to rest on the beams or other convenient supports of the'structure in which the evaporator is housed.

' The liquid to be evaporated may be supplied to themani f ol'dorliquid' sp aee25 below the tube cluster in anysuitable manner for instance through a pipe 32' opening intothe side wall of this manifold 25 and the liquid discharged by the tubes 20 intothe dome 10 i s-returned' from the latter tothe lower mani fold 25=by adownta'ke, which in the present instance preferably consists of an upright section 33 connected at its upper end with the upper flue sheet 1%,. and" communicating" with the lower end" of the dome in rear of the main baffle 1 6, and a lower elbow section connecting the lower end of the upright downtake section 33 with the sideof" the lower manifold 25. The height of the liquid under treatment within the evaporator may be observed by means of a glass gage 35' connected with the upri'glit section of the d'owntake.

As the liquid is heated in the tubes 20' it starts to boil, whereupon the'resulting-vapor and liquid will be discharged upwardly from the upper ends of these tubes into the inlet section or chamber 17 of the dome, the top of which is normally closed. In the upper part of chamber 17 is formed a vapor cushion. When the mixture of liquid and vapor is dis charged into this-chamber; 17 by the tubes 20, the heavy particles of liquid will'penetrate this cushion of vapor and may be deposited against the walls of the chamber 17, while the vapors are reflected by this cushion and flow through the passage under the battle 16 intochamber 18. Also due to the constant discharge of the mixture of liquid and vapor from tubes 20,.the vapor cushion formed directly above the tubes will be forced laterallyadjacent tozopposite vertical: edges of the hafiie. 16 and displace. some of the vapor in these spaces marked'50in Figs. 2: and 3:, thereby forcing the vapor-under'the bafile and into the: chamber 18.. During: such discharge of the liquid and vapor by the tubes 20 into the inlet chamber 17 the liquid and vapor are separated and-some of the liquid will adherev to the internalsurfaces of; the inlet chamber 17' formed by the adjacent part. of the wall. 11', the crown 12 and the main baffle sheet. 16, and flow downwardly on. these surfaces toward the" bottom: of. the dome. In order to prevent. the liquid which flows downwardly along the front portion of the wall 11 of. the dome from-interferingiwithl, the upward discharge of liquid andivapor from the tubes 2.0 into'the inlet chamber-I,1-7;,.a-n auxiliary baffle 36 is provided; which; is preferably curved; and mounted on the upper side of the upper flue sheet 14: between the front. side of. the tube; cluster 20 and the adjacent front por tion ofthe wall 11', as best shown in Figs. I and 3, this; auxiliary baflie being preferably curvedso; that any liquid which flows fromthe front part. of the. domewall 1 1 will be deflected laterally and rearward alongopposite lateral sidesv of the cluster of tubes 20, from. whence the same flows back into the upper end of the downtake 33- without liability of flowing toward the upper ends. of the tubes 20 and interfering with the discharge of liquidand vapor from the latter.

The vapor which is separated from the liquid the: inlet chamber or section 17 of the dome passesf-romthe lower end of. the latter rearward'ly through the passageway be tween the lower end of the bafile 1 6 and the upper fluev sheet 14L into the lower end of the outlet chamber or section 182 of the dome, thenceupwardly and through the outlet 19 at upper end of the outlet chamber 18., while the liquid passes from the lower rear part of; the dome into the downtake and is returned by. the latter to the manifold 25 preparatory to again entering the lower ends 'of' the evaporator tubes and being heated therein again and discharged into the inlet chamber of the dome, this operation being repeated" continuously and the unevaporated A liquid being circulated in this manner while the apparatus is in use. The passage-way connecting the lower ends of the inlet chamber 17 and the outlet chamber 18 of the dome is so constructed as to provide the maximum cross sectional area in this passage-way and permit the maximum flow of vapor from this inlet chamber to said outlet chamber without permitting any of the liquid which is being discharged upwardly from the tubes into the inlet chamber from llqeing thrown directly into the outlet cham- Inasmuch as the vapor and liquid issue or spout from the upper ends of the tubes 20 in the form of an upwardly enlarging cone, stream or blast, the central lower edge portion 87 of the bai'lle plate 16 is made longer than the side portions 38 of the same, this central extension 37 being near to the upper ends of the evaporator tubes forming the inner or rear part of the cluster and thereby prevents the spreading vapor and liquid as it issues from these rear tubes from being thrown directly from these tubes under the lower edge of the baffle 16 and into the outlet chamber 18. Those portions 38 of the lower edge of the baffle 16 on opposite sides of the central part 37 thereof are, however, farther away from the upper outlet ends of the cluster of tubes 20 and these lower edge portions 38 are therefore cut away, preferably on a curve or other suitable form, so that the lower edge of this bafiie diverges upwardly from the central part of the same toward opposite vertical edges thereof, so that a connecting passage is formed between the chambers 17 and 18-which is comparatively low at the center, as shown at 19, and comparatively wide at its opposite ends, as shown at 40 in Fig. 2. The fullest possible freedom is therefore provided for the escape of the vapor from the inlet chamber 1'? to the outlet chamber 18 without liability of liquid being spouted from the tubes 20 directly into the outlet chamber 18; The velocity of the vapors entering the inlet chamber 17 and passing into the outlet chamber 18 is therefore reduced, whereby entrainment of liquid in the stream of vapor is cor *espondinglv reduced. The components of the velocity are still further changed as the vapor changes its direction in passing around the lower edge of the baifle 16 and thence upwardly from the lower end of the outlet chamber 18 to the upper end thereof, inasmuch as thevapor at this time completely reverses the direction in which it flows and the component of the velocity rises from zero to its maximum in the top of the dome thus rendering it impossible for liquid to become entrained in the same.

In passing from the tubes 20 to th vapor outlet 19 the vapors change their direction three times, first in the inlet chamber 17 from an upward direction to a downward direction, next below the baiile 16 from a downward direction to a horizontal direction, then in the outlet chamber 18 from a horizontal to an upward direction.

By means of these repeated changes in the direction of the flow of the vapors the particles of liquid are projected by their inertia onto the walls of the dome and the baflie 16 of the evaporator, where they have an opportunity to flow together and be collected by the means provided for this purpose.

For the purpose of still further reducing the possibility of entrainment of liquid in the vapor as the vapor passes from the inlet chamber to the outlet chamber 18, means are provided whereby the liquid separated from the mixture and flowing downwardly on the front side of the bafile 16 is prevented from dropping ofl the lower edge thereof acrossthe entire width of this baffle which otherwise would formia continuous sheet, curtain or stream of liquid across the entire dome. The preferred means for accomplishing this consists of two gutters 39 arranged on the lower curved portions 38 of the baiile 16 and inclining from the side of the dome downwardly toward the central extended part 37 of the baffle 16, the opposing-inner ends of said gutters being spaced apart and discharging into a downwardly projecting spout 51 which is formed on this central downward extension 37 of the main battle and thereby serves to deliver the separated liquid close to the upper side of the upper flue sheet 14: forming the bottom of the dome so that the possibility of entraining liquid in the vapor is reduced to a minimum. 7

As a result of this construction the liquid striking the front side of the baflie 16 will flow downwardly thereon toward the lower edge thereof, that part of the liquid on the central part of the baiiie flowing directly from the lower edge 37 thereof on to the central part of the upper flue sheet 1 1, while those parts of the liquid flowing down the lateral or side portions 38 of the baffle 16 are caught by the gutters 89 and directed toward the spout 51 on the center of this bafiie where -1 it is also discharged upon the central part of the upper flue sheet, thereby leaving the two enlarged side portions 40 of the passageway between the inlet chamber 17 and the outlet chamber 18 unobstructed by any streams or sheets of liquid, and permitting the vapor to pass from the inlet chamber to the outlet chamber without passing through any shower or sheet of liquid thereby avoiding the possibility of entrainment of liquid in the vapors at these points.

Another important function of the large flat plate 14 forming the bottom of the dome, especially when concentrating milk products,

is that it acts as a deodorizer. A thin film of 5 also'be apparenttliat the upwardly divergent ture which. makes'it possible to-drive oil considerable of objectionable flavors.

lVlien the liquid has been. concentrated to the: desired: point the same; may be removed through the; outlet 41' which is preferably formed in the lower part of the downtakev and connected with a. pump. or other means ofthe manifold 25 which; is normally closed for removing the liquid as desired.

' For the purpose of cleaning the tubes when required, the same are filled with water up to theupper flue sheet 14, an attendant-then enters the inletcha-mber of'the dome through a manhole 42' which is normally closed by a cover 43 and operates upon the tubes from the upper end: thereof by means of a brush which permits of thoroughly cleaning the same. In like manner the operator can enter the-outlet chamber 1-8'through a man-hole 44: which is normally closed by a cover 45 for the purpose of cleaning the downtake 33, 34 by means of a brush or other suitable utensil. The removal of the refuse from the apparatus which has been thus detached from the evaporator tubes QO-and the downtake may be effected through. an opening in the lower end by a door i6. 7

Whenever the tubes 20 require repairing or renewal thesame may be removed from the apparatus or access may he had thereto through an opening 47 in the top-or crown of the dome which is normally closed by a cover48;

It will therefore be apparent that this construction of evaporator permits of thoroughlycleaning all parts of'thesame and thereby maintainthe apparatus in the most sanitary condition so that the product. resulting-from its usewil-lbe ofthehi'ghest quality. It will lower edge of the ballie 16 will permit the vapors to flow freely away from the inlet chamber- 1*? to the outlet chamber 18,. and thatthe gutters and spout formed on the side and central portions of thi's-bafiie. plate provide cross-sectional passage areas which. are

. unobstructed by liquid, thereby enabling the vapors to flow away'at a reduced velocity and under conditions least liable to; entrain any liquid therein. I

Onaccount of the simplicity of the constructi'onof this apparatus it is possible to make the main parts of the dome, such as the body, crown and upper flue sheet of expensive metal, such as nickel and stainless steel, and

to weld these members to each other and also to weld or otherwise connect the flue sheets smootlr joints between these members; which will reduce to a minimum the possibility of any of .thematerial under treatment from lodgingwithin: the apparatusand therebyrendering' the: same'highly sanitary.

It will benoted that in this construction the heating tubes 20 are much longer than the height of the inlet chamber 17 of the dome so that the liquid will be heated rapidly and discharged at a. high velocity from the upper ends of saidz tubes and the upper closed part ot the inlet chamber 17 is; of considerable height so that the same will hold a vapor cushion of substantial size intowhich the heated liquid is discharged by the heating. tubes and a separation. is effected within this inlet chamber: between the liquid and any vapors which have been formed.

I claim as my invention:

1.. An evaporator comprising a dome, a

baille' extending downwardly from the topof the dome andv terminating short of. the bottom thereof, heating tubes opening into the lower part of said dome 011 one'side of the-baffle, a liquid return at the lower part of said dome onthe opposite'side of said baflle, a vapor outlet at the top of said dome on the same side of the baffle as the liquid: discharge, an outer large ring supporting the bottom; of said dome to which the upper ends of the heating tubes are connected,'and asteam chest surrounding said tubes and, including an inner small ring arranged eccentrically withinthe large outer ring and formed integrally therewith and serving as asupport for said steam. chest.

2. An evaporator comprising an upright dome, avertical imperforate bafile arranged in said. dome diametrically across the central part thereof and dividing the space within the dome into an inlet chamber and an. outlet chamber and said baflle being connected at its upper end with the top of the'dome and connected at its opposite vertical edges-with opposite sides of the dome and having one part of its lower edge depressed and arranged close to the bottom of the'dome so'that liquidon the inlet chamber side of the baffle flows from the depressed edge of the same to thebottom of the dome, while another part of said lower edge is raised aconsiderable distance above'the bottom of said dome and. forms an enlarged passage through which the vapors, pass from the inlet'chambcr to the outlet chamber of the dome; a: plurality of upright heating tubes having their upper ends secured to thebottom of said dome and. opening into said inlet chamber, a heating chest surrounding said heating tubes a liquid supply chamber communicating with the lower ends of said. tubes, and a return pipe connecting said outlet chamber with said liquid supply chamber, said heating tubes being longer than the height of said dome so that the liquid heated therein will be discharged from the upper ends of said tubes at a high velocity into the upper closed part of the inlet chamber and said inlet chamber being of such height that a Vapor receiving space of considerable height and closed at its top is formed directly above the heating tubes, Which vapor space is adapted to hold a vapor cushion of substantial volume into which the heated liquid is discharged upwardly from the tubes and a separation of the Vapors and liquid is eiiected therein.

In testimony whereof I hereby aifix my signature.

MARTIN J. KERMER.

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