US2535996A - Evaporator - Google Patents

Description

Dec. 26, 1950 G. A. WORN ETAL 2,535,996

EVAPORATOR Filed Feb. 27, l9f 16 2 Sheets-Sheet 1 51' INVEN TORS y Wilma Eflrawlgl a 1' I ATTOR '1 Dec. 26, 1950 WORN ETAL 2,535,996

EVAPORATOR Filed Feb. 27, 1946 2 Sheets-Sheet 2 INVENTORS Germ: JZMOI'IZ 5 By W mire/7:5,!

ATTO E'Y Patented Dec. 26, 1950 EVAPORATOR George A. Worn, Greenwich, Coma, and William E. Brockel, Verona, N. J., assignors to The Lummus Company, New York, N. Y., a corporation ot Delaware Application February 27, 1946, Serial No. 650,412

2 Claims.

This invention relates more particularly to improvements in evaporators of the'shell-andtube type wherein the shell is provided with heat exchanger tubing so disposed as to be submerged by a body of liquid within the shell and provided with channel means for circulating a heating fluid through the tubing to vaporize the liquid by indirect heat exchange.

An important object of the invefition is to provide such an evaporator with improved features of construction devised to facilitate assembly, take-down and servicing.

A further object of the invention is to provide means facilitating insertion and removal of the heat exchanger tubing without disturbing the separating and liquid-returning means and other parts of the evaporator; 2

These and other objects and advantages of the invention will appear from the fo lowing descriptibn taken in connection with the accompanying drawings:

In the drawings:

Fig. 1 is a vertical longitudinal sectional view of an evaporator unit embodying the invention;

Fig. 2 is a transverse sectional view on the line 2-2 of Fig. 1;

Fig. 3 is an enlarged detailsectional view of the separator, taken on the line 3-3 of Fig. 2; and

Fig. 4 is an enlarged detail sectional view taken on the line 4-4 of Fig. 1.

The structure of the evaporator includes a cylindrical shell I supported in horizontal position by cradles 2. One end of the cylindrical body of the shell is closed by a dome-shaped end member 3 and the opposite end of the shell is closed by a flat plate 4. These end members may be welded or otherwise secured to the body of the shell. The end member 3 has a centrally located manhole 5 cosed by a detachable cover 6. A heating unit is mounted within the lower portion of the shel. This unit comprises a bundle of horizontal tubes 1. At one end of the bundle the tubes extend outwardly through an aperture 8 in the end plate 4 and are secured within a tube sheet 9 whose margins overlap the margins of the plate, around said aperture. A channel member I0 is disposed over the outer face of the tube sheet and has flanges abutting the tube sheet. The tube sheet and member ID are bolted to the plate 4, as at H and together form a complete outer channel exposed outside 0! the shell and norma ly closing the aperture 8. At the inner end oi the tube bundle the tubes are secured within a tube sheet l2, and a channel member or 2 bonnet I3 is bolted to the tube sheet and constitutes therewith a floating head forming an inner channel. The channel member H) at the outer end of the bundle is provided with inlet and outlet nozzles and with a partition whereby steam or other heating fluid may be passed through one group of tubes of the bundle to the channel [3 and thenceback to the channel 10. Preferably, as shown, the tube bundle is of flat, rectangular form in cross section so that a maximum number of tubes will be disposed below a given liquid level within the shell.

A pair of tracks M are arranged within the lower portion of the shell, beneath the tube bundle, and are rigidly secured in place as by welding to the shell, to the plate 4 and to bracing ears l5 projecting inwardly from the shell to intermediate points in the length of the tracks. The bonnet I3 of the tube bundle has projections l6 slidably engaging the tracks, and at an intermediate point the bundle has a tube-supporting p'ate I1 whose lower edge also slidably engages the tracks. Stay-rods [8 connect the tubesupporting plate to the outer tube sheet 9.. Said tube sheet also has a plurality of dowel pins l9 projecting inwardly and engaging the edge of the plate 4 at the lower side of the aperture 8. The bonnet I3 has a lifting lug 20, and directly overlying same there is a transverse angle-iron 2| welded at its ends to the shell. The lifting lug, by engagement with the ang e-iron, prevents upward displacement of the floating head of the tube bundle.

A liquid-distributing pipe 22 is disposed beneath the tube bundle and laterally snaced from the vertical center line of the shell. At its upper and lower sides and at its side toward said center line the pipe 22 has longitudinal rows of jet holes 23. Lugs 24 welded to the shell and to the pipe 22 support the latter in place. The pipe is closed at both ends and, near one end, an inlet nozzle 23a is connected thereto, for supply of liquid to the shell. The shell is provided at the under side thereof with a pair of blow-down nozzles 25 of different diameter. The smaller of these nozzles is used for continuous bowdown of the evaporator and the larger one is used for intermittent blow-down of the evaporator. Each projects upwardly into the shell, is closed at its upper end and provided with lateral discharge holes. The shell is also provided with a nozzle 26 for attachment of a safety valve, and nozzles or pipe connections 21 for connection of gauges, or the like.

The entrainment separator employed is or a type such as that disclosed in U. 8. Patent No. 1,896,894 of C. G. Hawley. The separator, designated 28, has a cylindrical body portion provided with a circumferential series of substantially tangential vapor inlet ports 29. These ports, in cooperation with a member 30, defining an inverted cone within the lower portion of the separator, impart a swirling motion to the vapor received within the separator to separate entrained liquid by centrifugal force and discharge the separated liquid into trough- like collector chambers 31 and 32 located respectively above and below the vapor inlet ports. The separator is supported within the upper portion of the shell by vapor outlet nozzle 33. The latter is welded within an aperture in the upper side of the shell, projects downwardly into the shell and has a screw-threaded connection 34 with the separator. The separator is thereby supported with its central space in axial alignment with the nozzle and in direct communication therewith through a discharge port 35. Drain pipes 36 and 31 lead downwardly from the liquid- collecting chambers 31 and 32 respectively and extend past opposite sides of the tube bundle. These drain pipes are spaced sufliciently from the tube bundle to permit free passage of the floating head in insertion and removal of the bundle. At their upper ends, said pipes have releasable screw-threaded joint connections 38 with nozzles or pipe sections leading from the said liquid-collecting chambers. The lower end portions of the drain pipes have lateral ears 39 bolted to lugs 40 welded to the shell.

The type of separator described aiIords low pressure drop, operates well under a high rate of vapor delivery and its described embodiment in an evaporator contributes much to the efficient operation of the latter. The disclosed mounting and arrangement of the separator and its drains with reference to other parts of the evaporator is also very advantageous in its simplicity and in its provision for ready disassembly and servicing of the parts. Ready access to the separator is afforded by the manhole so that the drain pipes may be detached and the separator may be detached by unscrewing it from the vapor outlet nozzle. The tube bundle may also be removed without interference of the separator drain pipes. After release of the bolted connections II the tube bundle may be removed endwise through the shell port 8, the floating head proiections l8 and the tube-supporting plate I! sliding along the tracks I 4 and steadying the bundle in the withdrawal thereof. A port 4| closed by a detachable cover 42 affords cleaning access to the bottom of the shell. Insertion of the tube bundle is assisted by the floating head projections I3 and by the dowel pins ill at the opposite end of the bundle. The projections I6 guide the floating head in its passage through the port 8 and the dowel pins guide the opposite end of the unit into place. The projections l6 also assist removal of the bundle by supporting the floating head after it has passed outwardly through the port 9, until a hoisting means has been anchored to the lifting lug 20.

At one side thereof the shell is provided with a surface blow-down nozzle 43. Inwardly of this nozzle the shell has a weir 44 over which foam flows from the surface of the liquid to the nozzle It is, of course, to be understood that the present disclosure or our invention is merely illustrative and in nowise limiting and that the inventon comprehends such modifications as will come within the scope oi. the following claims.

We claim:

1. In a heat exchanger comprising a shell having a vertically extending wall formed with a horizontally opening aperture, a substantially horizontal bundle of heat exchanger tubes extending longitudinally into the shell from said aperture, and channels at opposite ends of said tube bundle to circulate through the tubes of the bundle fluid for indirect heat exchange with a fluid within the shell, one of said channels being exposed outside of the shell and normally closing sail aperture; tracks extending inwardly from the aperture to support the bundle for endwise travel therealong, said tracks being flush with an edge of said shell wall forming the lower side of said aperture, an anchorage for hoisting tackle borne by the inner one of said channels, and guiding and supporting projections borne by said inner channel, engaging said tracks and extending longitudinally of the bundle materially beyond said inner channel and beyond said hoisting tackle anchorage, said aperture, bundle, channels, tracks and projections being correlated to enable unobstructed withdrawal of the bundle and said inner channel endwise along the tracks and through the aperture and said projections being of a length beyond the channel to remain in engagement with said wall edge after withdrawal of said channel and tackle anchorage therethrough, to support said channel for connection of hoisting tackle thereto.

2. In a heat exchanger according to claim 1, the structure claimed in said claim and including an inwardly extending guiding and supporting projection borne by the said outer channel and disposed to engage the said edge defining the lower side of the said aperture, to guide and support the outer channel in the insertion and removal of the bundle.

GEORGE A. WORN. WILLIAM E. BROCKEL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 6,671 Stillman Aug. 28, 1849 1,617,081 Price Feb. 8, 1927 1,760,907 Jones June 3, 1930 1,832,412 Newton Nov. 17, 1931 FOREIGN PATENTS Number Country Date 4,550 Great Britain Jan. 2. 1913 of 1912

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