US2172236A - Evaporator - Google Patents

Description

Sept. 5, 1939. A. w. BAUMANN EVAPORATOR' r 2 Sheets-Sheet 1 Filed June 5, 1,937

Sept. 5, 1939. I 'w BAUMANN 2,172,236

EVAPORATOR 2 Sheets-Sheet 2 Filed June 5, 1937 in v (EL Patented Sept. 5, 1939 UNITED STATES PATENT OFFICE EVAPORATOR Arnold W. Baumann, Chicago, Ill. Application June 5, 1937, Serial No. 146,567

2 Claims. (01. 159-31 This invention relates to an evaporator of the type known as a vacuum pan and intended for use in the condensation of milk or other liquids. One object of the invention is to secure increased efliciency in the transmission of heat from the heating medium, such as steam, to the liquid under treatment. Another object is to reduce to a minimum any possible loss which might result from a part of the material being carried out of the evaporator in the current of vapor discharged therefrom. Another object is to improve the internal structure of the apparatus to render it completely sanitary and relatively easy to clean. Other objects will appear from the description which follows. The invention consists in certain features and elements of construction, in combination, as herein shown and described and as indicated by the claims.

In the drawings:

Figure 1 is a side elevation of an evaporator embodying this invention, a portion of the side wall being broken away, and certain internal parts being shown in section.

Figure 2 is a side elevation of the evaporator taken at right angles with respect to- Figure 1, and with the lower portion of the side wall broken away to show the arrangement of the heating coils.

Figure 3 is a transverse section taken as indicated at line 33 on Figure 1.

Figure 4 is a detail section showing the joint between the lower and upper chambers of the evaporator on a larger scale than in Figure 1.

Figure 5 is a transverse section taken as indicated substantially at line 55 on Figure 2 for showing one of the heating coils in plan view.

Figure 6 is a detail section taken as indicated at line fi6 on Figure 5 to show the steam-distributing means for the multiple coil.

Figure '7 is a detail section taken as indicated at line l-'-'l on Figure 5 to show the construction of the outlet for the coil.

As shown in the drawings, the evaporator includes two cylindrical chambers, a lower chamber, I, into which the liquid to be treated, such as milk, is fed through a tangentially arranged inlet, 2, and where it is subjected to heat provided by steam introduced into suitable pipes or coils in the lower portion of the chamber, I. Super-imposed upon the chamber, I, is a vacuum chamber, 3, into which the vapor is discharged from the chamber, I, and from which it is drawn by the action of a partial vacuum. The vapor outlet, 4, is shown surmounting the chamber, 3, and may be understood to be connected to suitable condensing apparatus, not shown.

The upper wall, 5, of the chamber, I, is formed with a central throat, 6, defining the discharge passage for the water vapor rising from the milk or other liquid under heat-treatment. The chambers, I. and 3, being maintained under partial vacuum, permit the liquid under treatment to boil at a temperature below its normal atmospheric boiling point, and its tendency is to boil up rather actively in the chamber, I. As a result, some ofthe solid particles of the milk tend to be carried up in the water vapor which is being separated by the heating process, and may be carried over through the outlet, 4, into the condenser. This represents a definite loss of the material which the evaporator is designed to reclaim from the milk. To prevent such loss I provide a deflecting bafile, I, disposed over the upper end of the throat, 6. If this baflle were formed so as to receive the direct impact of the vapor issuing from the throat, 6, there would be a tendency for some of the solids to be deposited on the baffle. Therefore, to avoid this direct impact and alter the direction of flow more gently, this deflector is formed with a central, conical point, 8, and with an annular, concave surface, 9, extending radially from the point, 8, and beyond the rim, III, of the discharge throat, 6. Thus the rising column of vapor is split or spread by the pointed bafile, l, and its direction is gradually changed so that it is discharged over the rim, I0, of the throat, 6, in a downwardly inclined direction toward the outer cylindrical wall of the upper chamber, 3, and near the bottom of this chamber. This requires the vacuum Working through the outlet, 4, to reverse the vapor current and cause it to flow upwardly toward the outlet, 4. Furthermore, as the vapor emerges from the relatively small throat into the larger chamber, 3, its velocity is materially reduced. Thus the change of direction and velocity permits the solid particles which may be entrained in the vapor stream to precipitate in the chamber, 3, along with some portion of the vapor which may condense in this part of. the apparatus. This material will flow back into the lower chamber, I, through drain pipes, I I, provided for this purpose leading from the bottom of the chamber, 3, and terminating, if desired, in the goose-necks, I2, which tend to prevent the rising vapor currents in the chamber, I, from interfering with down-flow of the condensed liquid through the pipes, II.

In some instances there is a tendency for the vapor in the chamber, I, to .acquire a swirling motion, which would be maintained through the discharge throat, 6, and also in the upper chamber, 3, sweeping the solid particles along with it, and preventing their deposit in the upper chamber, 3. But by including in the deflector, 1, one or more radial vanes, I3, I am able to check this swirling motion and retard the flow as the vapor traverses the under surface of the deflector, I. Figure 3 shows three such vanes, l3, spaced equally and extending radially with respect to the central point, 8, of the deflector. The deflector, 1, may be mounted in any suitable manner; as shown, I provide posts, l4, extending above the rim of the throat, 6, and having their 5 upstanding portions threaded to receive clamping nuts, I5, disposed above and below the deflector, l, to secure it. By reason of the threaded construction the deflector may be adjusted toward and from the rim, III, of the throat, 6,

to secure the best results under given conditions.

In constructing the evaporator with two chambers, as shown, I prefer to complete the lower chamber, l, with a head or top wall, 5, and including the throat, 6. The upper chamber is a simple, cylindrical drum with its side wall, I6, bent inwardly at the bottom to meet the convex surface of the wall, 5, of the chamber, 1. This inturned flange, I7, is then welded to the wall, 5, witha substantial fillet, |8, of welding material inserted between the diverging surfaces ofthe flange, H, and wall, 5, .and with additional welding material, I9, abutting the cut inner edge of the flange, IT, and merging smoothly with the upper surface of the wall, 5, as seen in Figure 4.

This provides a sanitary surface which may be easily flushed, and will not afford lodgment for any solid material in this portion of the apparatus. A reinforcing band, 20, is welded around the outer surfaces of the cylindrical walls of the tanks, and 3, to complete the junction.

The drain pipes, may be conveniently suphuiuq oiuuuuiuihqpouppunhuo IIW MW Wi Winmui tending into the tube, 26, in advance of its connection to the tube, 2|, is a metering throat, 21, of smaller diameter than the tube, 26, and connected directly to the coupling sleeve, 28, which leads to the second tube, 22, of the coil. 5 This provides an annular inlet, 29, through Which the steam enters the tube, 2|. A second metering throat, 3|], connecting with the third tube, 23, extends into the coupling, 28, and forms an annular passage, 3|, through which 10 the proper quantity of steam is admitted to the second tube, 22, while the remainder flows directly through the throat, 30, to the tube, 23. In this way the supply of steam entering at 26 is cut into three portions, properly related 15 to the relative capacities of the tubes, 2|, 22 and23, so as to afford uniform heating action from all three tubes. At the outlet end of the coil the three tubes, 2|, 22 and 23, are shown connected to a common discharge coupling, 25. b The coils are joined by tubular coupling members, 32, welded in place, and, as indicated in Figure 7, the lower side of the discharge passage thus formed by the tubes, 32, and outlet coupling, 25, is in substantial alignment with the 25 bottom walls of the tubes, 2 I, 22 and 23, in order to insure the discharge of any water condensed from the steam therein.

I claim:

1. In an evaporator for milk or the like, a 30 heating chamber in which the milk is contained us a single continuous body of liquid with o 0010 "Iii ill lii vh luu I A H I uuuuuouuuuou oqluuuu his iu i V i n NW i.

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