US2351239A - Heat exchanger - Google Patents

Description

Jur ae 13, 1944. w. H. THOMPSON HEAT EXCHANGER Filed Sept. 19, 1942 2 Sheets-Sheet l INVENTOR M//,L/A/ l h. THOMPSON.

f K M ATTORNEY June 13, 1944. w. H. THOMPSON HEAT EXCHANGER Filed Sept. 19, 1942 '2 Sheets-Sheet 2 INVENTOR Mum/v THOMPSOM BY r ATTORNEY Patented June 13, 1944 HEAT EXCHANGER William H. Tl1ompson, Chathani, N. .L, assignor to Davis Engineering Corporation, Elizabeth, N. J a corporation of Delaware Application September 19, 1942, Serial No. 458,933

('01. era-23s) 2 Claims.

The invention herein disclosed relates to a heat exchanger of the kind in which the fluids between which an exchange of heat takes place are not permitted to commingle, such for example, as a heat exchanger in which the heated medium passes through tubes and the medium to be heated is brought into contact with the tubes.

In a heat exchanger of this kind, the continued efliciency of heat transfer from the heating medium to the medium to be heated is dependent upon the cleanliness of the heat transfer surfaces. In oil heaters, for example, the heating medium, steam, is caused to flow through tubes and the oil to be heated is brought into contact with the external surface of the tubes. For increased emciency in effecting the heat exchange and greater capacity per cubic foot of space occupied by a heat exchanger of this kind, it is'desirable that bafiies be provided in the heater arranged to cause the oil to be heated to make a number of passes across the heated tubes between the inlet for the oil and the outlet therefor. After use for a comparatively short period, a film and scale deposit upon the heat transfer surface, the outside surface of the tubes. Such deposits reduce the heat conductivity and so the efficiency of the heater.

Generally, as heretofore constructed, it has been necessary, in order to maintain the heat transfer efliciency and capacity of the heater, to dismantle the heater and clean the heat transfer surfaces. It is an object of this invention to provide a heater of this kind in which the heattransfer surfaces may be mechanically scraped without opening the heater. It is a further object of this invention to provide such a heater with an arrangement whereby the heat-transfer surfaces of the heater may be readily and easily cleaned during the operation of the heater.

These objects and certain advantages that will hereinafter appear are realized in the heat exchanger disclosed in the accompanying drawings. This heat exchanger constitutes one specific embodiment of the invention and it is, with reference to the drawings, described in detail below. The drawings include:

Fig. 1 which is a longitudinal elevation of the heat exchanger;

Fig. 2 which is a transverse section of the same;

Fig. 3 which is a partial, longitudinal section of the same taken on the line 3-3 of Fig. 1; and

Fig. 4 which is a like partial, longitudinal section of the opposite half taken on the line 4-4 of Fig. 1.

The heater illustrated in the drawings includes a cylindrical shell I having an end flange 2 at one end and a like end flange 3 at the other end. It is provided adjacent the flange 2, with an inlet opening 4 and a coupling 5 through which a pipe connection may be made with the inlet. Adjacent the other end flange 3, an outlet opening 6 is provided and a coupling 1 through which a pipe connection may be made with the outlet. Intermediate the ends of the shell there is provided a relief connection 8 which communicates with the shell through the opening 9. Couplings I0 and II are secured to the shell for connection to columns for supporting the heat exchanger. A drain connection I2, communicating with the shell, is also provided on the lower surface of the shell.

To the end flange 2, there is secured a'tube sheet or plate I3. This tube sheet is secured to the flange by bolts i4 extending through the flange I5 of a head I6, the tube sheet and the flange 2. Between the tube sheet and the flange I6, there is a packing ring I1, and a like packing ring I 8 is between the tube sheet and the flange 2. The ends of a plurality of tubes I9 (seven in number), are secured in the tube sheet I3 and these tubes extend longitudinally of the shell I to a point adjacent the outlet 6. The ends of these tubes, adjacent the outlet 6 are closed, and for a short distance reduced in diameter.

The head I6 forms a chamber 20 between the tube sheet I3 and another tube sheet 2| formed within the head I6. Within the tube sheet 2|, the ends of a plurality of tubes 22, seven in number, are secured. Each tube 22 is alined with a tube I9 and extends into and to the reduced end of the tube I9 in which it is received. Adjacent the end of each tube 22, that is received in and supported by the reduced end of a tub I9, there are provided a plurality of radial openings 23 placing the tube 22 into communication with the tube I9. The end of the head I6 is spaced from the tube sheet 2| and forms therewith a steam inlet chamber 24, the end of the head having a tapped opening 25 for the admission of steam to the chamber. A condensate opening 26 communicates with the chamber 20, which is also provided with a vent opening 21. Thus, steam admitted through the inlet 25 will pass along tubes 22, through the openings 23 and back along the tubes I9 to the condensate chamber 20 and out through the condensate outlet 26.

Within the shell, ther are a plurality of spaced, transverse bafiles 28. These bailies are circular disks with a section removed, the edge 29 of which is parallel to a diameter. The baffles are located between' the inlet and outlet openings to the shell and have openings therethrough; through which the tubes I9 extend. Successive baflles are turned through one hundred and eighty degrees and the baflles engage the wall of the shell except at the cut-out section which provides a passage past each baflie. Thus, oil entering the inlet 4 i caused to flow across the tubes, under the baflie 28 adjacent the inlet, again across the tubes and over the next succeeding baflle and so on flowing transversely of the tubes between baflles to the outlet 6.

The several baflles are also provided with openings, four in number angularly spaced through angles of ninety degrees, to receive rods 30. These rods extend through theseveral bailles and are threaded at each end. At one end, the rods are provided with nuts 3i which engage spacer sleeves 32 between the nuts and the first in the series of baiiles. Like spacer sleeves 33 surround the rods between successive baflles. The opposite ends of the rods extend fromthe last baflle, ad-

jacent the outlet, and through a head or carrier 34. Spacer sleeves 35 surround the rods between the last baflie and the head 34. Nuts 35' on the ends of the rods secure the rods to the head and, through the spacer sleeves, secure the baffles, rigidly, in proper spaced relation.

A spindle 36 is, provided with a reduced, threaded end section 3! that extends through an opening therefor provided centrally of the head. The spindle is secured in the head against relative longitudinal movement with respect thereto by a. nut 38 threaded on to the reduced end of the spindle. The spindle extends through an end plate 39 secured to the end flange 3 and closing the end of the shell. The end plate is provided with a threaded opening centrally thereof in which the hollow boss 40 of a bracket 4| is received. Through this boss, and a packing gland 42 provided therefor, the spindle 36 extends, and it is slidable in the boss. The end portion of the spindle is provided with a thread 43 that is received' in an internally threaded boss 44 rigidly secured in the bracket 4i. On the end of the spindle a hand wheel 45 is mounted. As the hand wheel is turned, the spindle is turned and through its threaded connection with the boss 44 moves longitudinally.

The baflies 28 make a scraping'fit with the tubes I9 and are movable in the shell. They are positioned and supported through the rods 30. As the spindle 86 is moved longitudinally as above described, the baflles 28 are moved along the tubes. By so moving the bailies back and forth a short distance, the tubes are scraped clean and thus the heat transfer surfaces of the tubes may be maintained free of deposits and scale which impair the heat conductivity. It will be appreciated that the baflies may be thus moved while the heat exchanger is in operation.

It will be obvious that various changes may be made by those skilled in the art in the details of the embodiment of the invention illustrated in the drawings and described above within the principle and scope of the invention as expressed in the appended claims.

I claim:

1. In a heat exchanger of the kind described,

the combination comprising a shell having inlet and outlet openings for the medium to be heated, tubes within the shell extending longitudinally thereof for carrying the heating medium, a plurality of spaced, transverse baffles within the shell between said inlet and outlet openings, the baflles engaging the tubes and the wall of the shell and arranged to cause the medium to be heated to make a plurality of passes transversely of the tubes and being movable longitudinally of the tubes and making a scraping fit therewith, means connecting the several bailles together and arranged to sustain the battles transverse to the tubes, and means for moving the baflles along the tubes, whereby the baiiies scrape the tubes.

2. In a heat exchanger of the kind described, the combination comprising a shell having inlet and outlet openings for the medium to be heated, tubes within the shell extending longitudinally thereof for carrying the heating medium, a plurality of spaced, transverse baflies within the shell between said inlet and outlet openings, the baffies engaging the tubes and the wall of the shell and arranged to cause the medium to be heated to make a plurality of passes transversely of the tubes and being movable longitudinally of the tubes and making a scraping fit therewith, means connecting the several bafiies together and arranged to sustain the battles transverse to the tubes, and means operable externally of the shell for moving the baiiies along the tubes, whereby the baflles scrape the tubes.

WILLIAM H. THOMPSON.

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