US1846955A - Heat exchange apparatus - Google Patents

Description

H. H. DOW

Feb. 23, 1932.

HEAT EXCHANGE APPARATUS 2 Sheets-Sheet Filed Aug. 26, 1926 A INVENTOR. ,J/erberz J1. 170W BY 6 M a @944 ATTORNEY.

Fb. 23, 1932. H, D W 1,846,955

HEAT EXCHANGE APPARATUS Fil-ed Aug. 26, 1926 2 Sheets-Sheet 2 INVENTOR.

ATTORNEY HERBERT ly where there Patented Feb. 23, 1932' UNITED Ji STA Es ATENT;- oFFIca PAITY, OF MIDLAND, MICHIGAN, A CORPORATION OF MIGHIGAN HEAT APPARATUS Application filed Au ust 28, 1926. Serial 1rd. 131,798.

This invention relates to systems involving a step of heat exchange, and more particularis considerable difference 10 pressure between the fluids concerned or where there is possible danger if interleakage should occur. It is among the objects of the invention to provide such systems, a safeguard in these contingencies. objects and advantages will appear as the description proceedsi Tovthe accomplishment of the foregoing and related ends, the invention, then, consists in the features'hereinafter fully described, and particularly pointed out in the claims, the following description and the annexed drawings setting forth but few of various forms in which the may be employed.

Insaid annexed drawings Fig. 1 is a schematic view in section of an embodiment of my invention; and Fig. 2 is a similar view of a modification.

In its general aspects, my invention contemplates a system including a means for containing a hot fluid, and a meanslfor containing a fluid to be heated, there being an" intermediary fluid for transferring heatfrom the one to the other.

In Fig. 1 reference'numeral 1 designates a container for the fluid to be heated. De-

pending upon the particular application of the invention, this will vary, but for example may be! a boiler for containing water to be heated. An outer-set ofpartitions or tube sheets 2, 3, and an inner set of partitions or tube sheets 4, 5,'are arranged in the container 1, and tubes 6 extend between theinner tube sheets 4, 5, while smallertubes 7 extend be. tween the outer tube sheets 2, 3, and lie within the tubes 6. There is thus, provided a compartment A having-a well or larger channel 8 arranged as desired, and a series of tubes 7 connecting the respective portions of the compartment, while an inner. compartment B is formed in relation to the compartment A and having a connection 9 as an=inletfor a hot fluid andv an outlet 10. Between. these respective compartments A and B, there is thus a third. general compartment C, this comprising the space between the partitions having Other.

principle of the invention I 2 and 4 and the tubes 6 and 7 and the partitlons 3 and 5. Preferably I connect this ."general compartment C with. anexpansion chamber or standpipe l1, and to accelerate .the circulation, it is desirable to include a pump 12 in the circuit between the chamber 11' and the compartment C.

With a fluid such as water in the chamber A, and a fluidin the chamber B to give up heat to such water, it will thus be seen'that the respective fluids are separated by the intermediary compartment C which, is pro vided with a heat-transfer fluid of suitable character. Desirably this heat-transfer fluid is maintained in active circulation, preferably such as to involve turbulence; In this manner a more effective transfer is realized. If now, the difference of pressure between the fluid in chamber A and the fluid in chamber B be considerable, there will be a tendency toward leakage through joints, and if the pressure in chamber C be sufliciently lower than that in chamber A such leakage will be seen to occur from chamber A into the intermediary fluid in chamber C. This inter: 'mediary not only allows of a. stepping down various chambers, i. e.,-from a working pres-' sure inchamber A to lower pressures in chambers B and C, although the pressure of fluid in chamber 0 may be at approximately a. DOW, or unite in), MICH GAN, asslenon' ro ran now GHEIHGAL oonrof pressure gradient of the fluids in the 7 that of the fluid in chamber B or higher than I such pressure, but in the case of suchv fluids as on mixing would start detrimental action, I am thus enabled to interpose an eflective barrier by virtue of such intermediary fluid in the chamber C. For instance, .if thefluid'in compartment A be water and. the fluid in compartment'B were aluminum bromide to be condensed from vaporous state, the tem- .perature of such bromide under'a pressure of one atmosphere is above 506 F. while water in the compartment A at a temperature raised say to 486 F. would represent a pres-- sure of about 600 pounds'absolute, thus involving a difierential which would be ex tremely diflicult tohold even by the best possible seams, and any leakage of water into the aluminum bromide compartment would result in the formation of hydrobromic acid in relation to a shell with partitions or tube sheets 27, 28. Tubes- 29 extend between these tube sheets and a with disastrous results. The intermediary compartment C in such case would thus fur-- nish an additional'set of barrier Walls and a. corresponding stepping down of the abrupt pressure gradient, and at the same time by proper selection of the intermediary. fluid in the compar'tmentC, all danger of disastrous interaction in case of leakage will be'avoided. Carrying the foregoin illustration further, if the intermediary fluid be for instance diphenyl oxide, its boiling point .at a pressure of one atmosphere is about 496 F., thus giving an intermediary which allows of ready heat-transfer from the aluminum bromide to the water compartment, and any leakage from the water compartment under its relatively high pressure would occur into the diphenyl oxide with harmless results. By

adding a-condenser system including a condenser 13 having suitable cooling means, and a drawofl' pipe 14 to a separator .15, any leakage occurring from the water compartment A into 0 would be in state ofvapor and would pass oil from the top or vapor space 16 of the receptacle 11 along with any diphenyl oxide vapor to the condenser 13 where both would be condensed and flow'down to the separator 15. In this the water would stratify above the di henyl oxide condensate and would flow 0E diphenyl oxide would return by pipe 17 and trap 18 to receptacle 11. a

In the form shown in Fig. 2, instead of including the heating fluid chamber'B within the walls of the container 1, it is located outside. 'A set of partitions or tube sheets 19, 20, is provided. and tubes 21 extend therebetween, there being also if desired a well 22. The chamber A thus has tubes joining its different portions, and immediately surrounding the tubes is an intermediate chamber C. Baflles 23 may be arranged in this compartment to provide a more eflicient distribution of the fluid therein. Connecting with the compartment C is an inlet 24 and an outlet 25 26 which is provided partition 30 may be arranged in the header space sons to more eflectively divert the-fluid to flow through the tubes. Between the partitions or tube sheets 27, 28, there is thus formed a general compartment B having an inlet connection 31 and an outlet connection 32. In this arrangement a hot fluid for instanceis passed in from any source through connection 31, and circulates about the tubes 29 to the outlet connection 32, giving up heat h inits passage to the fluid inside of the tubes, if

this being circulated, preferably actively by pump 33 so as to pass around through the compartment'C in the container 1 and there by give up heat to the fluid in compartment An expansion tank or standpipe 34 is desirably arranged in relation with the comthrough the overflow 16, \while the b .ed therewith providin partment C, and a condenser system includthis makes possible the handlin of chemical substances either in'the sense 0 cooling and condensing on the one hand, or heating and compartment and intermediary heat-tran er fluid 1s vided between the main fluids concerned, and

vaporizing on the other, without detrimental 5 effects from leakag. .Moreover, a power plant utilizing the properties-of high boilv ing liquids may be arranged on this order,

for instance a high boiling point substance such as aluminum bromide can be used as a primary power-vapor giving up its energy'to a turbine or the like, to its boiler through a heat exchange relationship with water in erate steam which may be used as a secon ary power-fluid in a corresponding unit, and with the intermediary heat-transfer fluid as contemplated by this invention, the large pressure difl'erential can be readily handled without dangers which would otherwisebe' inherent in attempt at conjoint use of such agents.

This invention will thus be seen to be capale of application with various substances a water boiler to en and in various relationships, where an intermediary heat transfer agent can be employed to eliminate dangers otherwise inherent.

Other modes of applyin the principle of the invention may be ing made as regardsthe features disclosed,

emp oyed, change beprovided the means or steps set forth in any. of the following claims, or the equivalent of such, be employed,

I therefore particularly point out-and distinctl' claim'as my invention i.

1. n apparatus of the character described, the combination of a container for a fluid to be heated, outer and innersets of tube sheets therein, tubes extending between the inner tube sheets, smaller tubes positioned within said tubes and extending between the outer tube sheets, an external container in communication with the tubes which extend between the inner tube sheets, and a pump for circulatin a fluid through said-external container and communicating tubes.

2. In apparatus of the character described,

the combination of a container for a fluid to be heated, a double set of partitions associate ing fluid and a charm r intermediate for a eat-transfer'fluid, and means for separating rom such heat-transfer fluid leakage-contaminations of other fluid.

3. In apparatus of the character described, the combination of a container for a fluid to be heated, a container for a heating fluid, anintermediate container in heat exchange relation with both the aforesaid for containing a chamber for a heat: 4

a heat-transfer -fluid, a pump for circulating such fluid through said intermediate container, a Vapor off-take from the top of said intermediate container, a condenser for said vapor 5 ofi-take, a separator for condensate, and a,

connection from the separator to said intermediate container. v

Signed by me this 20th day of August, 1926. 10 HERBERT H. DOW.

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