US1716333A

US1716333A - Heat-exchange apparatus

Info

Publication number: US1716333A
Application number: US125534A
Authority: US
Inventors: Vuilleumier Rudolph
Original assignee: Safety Car Heating and Lighting Co
Current assignee: Safety Car Heating and Lighting Co
Priority date: 1916-10-14
Filing date: 1916-10-14
Publication date: 1929-06-04
Anticipated expiration: 1946-06-04

Description

June 1929- R. VUILLEUMIER HEAT EXCHANGE APPARATUS Original Filed Oct. 14, 1916 2 Sheets-Sheet FIG M V awuewfoz 351 flflozwug;

I- J M June 4, 1929. R. VUILLEUMIER 1,716,333

HEAT EXCHANGE APPARATUS Original Filed Oct. 14, 1916 2 Sheets-Sheet 2 FIGS. FIG. 7.

Patented June 4, 1929.

UNITED STATES PATENT OFFICE.

RUDOLPH VUILLEUMIER, OF NEW ROCHELLE, NEW YORK, ASSIGNOR TO THE SAFETY CAR HEATING & LIGHTING COMPANY, A. CORPORATION OF NEW JERSEY.

HEAT-EXCHAN GE APPARATUS.

Application filed October 14, 1916, Serial No. 125,534. Renewed December 6, 1920. Serial No. 428,816.

This invention relates to the transfer of heat, and with regard to certain more specific features, to an apparatus for low temperature work.

One of the objects of the present invention is to provide simple and durable apparatus for effecting a rapid transfer of heat between two fluids.

' Another object is toprovide an apparatus of high thermal efiiciency for conducting heat from one fluid to another without sacrifice of mechanical strength or economy of construction.

Another object is to provide a compact and reliable heat interchanger or economizer capable of effective operation with but a slight difference in temperature between the warm er and the colder fluids, and operating at minimum external heat losses.

Other objects are to provide apparatus of the above general type in which the temperature gradient across the paths of the fluids is minimized, and the temperature gradient along the paths of the fluids is maintained at a maximum.

Other objects will be in part obvious and in part pointed out hereinafter.

The invention accordingly comprises the features of construction and operation, combinations of elements, and arrangements of parts which are exemplified in the structure hereinafter described and the scope of the application of which will be indicated in the following claim.

In the accompanying drawings, in which are shown one or more of various possible embodiments of this invention,

Figure 1 is an elevation, partly in section, of a counter-current'recuperator.

Figure 2 is a transverse section on the line 22 of Figure 1.

Figure 3 is a View similar to Figure 1, of a multiple-path construction, in which one of the fluids is caused to pass through a plurality of conduits within the container for the second fluid.

Figure 4 is a transverse section on the line 4-1 of Figure 3.

Figure 5 illustrates a modified construction comprising concentric coils for'one of the fluids, with no heat-conducting solid particles within the conduits for said fluid formed by said coils.

Figure 6 is a transverse section on the line 66 of Figure 5.

Figure 7 is an elevation partly in section, of a cross-current recuperator utilizing a coil for one fluid wound within an annular conduit for the second fluid, with heat-conducting beads in contact with the second fluid on y.

Figure 8 is a transverse section on the line 8-8 of Figure 7.

Similar reference characters refer to similar parts throughout the several figures of the drawings.

In considering the present invention with relation to the prior art, it may be noted that for many years attempts have been made to transfer heat effectively from one fluid to another, as in high and low-temperature work. The apparatus used for this purpose has ordinarily been of one or two types: first, the sothermal contact; in this type of appar'atus,.

the'heat is transferred continually through the walls separating the fluids. In both the regenerator and rccupcrator types it is preferable, but not essential, that the fluids flow in opposite directions, or at least notin the same direction, and this opposite flow is known'as the counter-current system. The rapid transfer of heat from one fluid to another fluid of almost the same temperature, together with economy of construction, mechanical strength to withstand the high and low pressures utilized, and the prevention of frost or other prejudicial phenomena in the case of low-temperature work, are desiderata not adequately attained in apparatus and processes now known in the art. As the description proceeds, it will be seen that these and other advantages are realized in the present invention.

Referring now to the accompanying draw- I tube for a fluid A. 1 Surrounding this conduit is a second conduit or container 2 provided with suitable heat insulation or packing 3 to protect it from the atmosphere, and so arranged that a second fluid B may pass through the space between the inner wall of the outer conduit 2 and the outer wall of the mner conduit 1, preferably in a direction opposite to the flow of the fluid A, as indicated by the arrows B, A, respectively, in Figure 1. i

The wall of the inner conduit 1 is of such material and thickness that it has a fairly high thermal conductivity, so that heat imarted to this wall from one of the fluids will be transmitted through the wall, where it may be absorbed by the other fluid.

In order to increase the transfer of heat from one fluid to the other, without involving the use of an expensive or mechanically weak wall 1, the channels through which one or both of the fluids may be passed are preferably filled with solid matter of comparatively high thermal conductivity, such as copper beads. In Figures 1 and 2, both channels a and b are filled with copper heads 5;

. in other embodiments of the invention, de-

scribed hereinafter, these heat-conducting particles are utilized only in the channels for one of the fluids. Copper having a thermal conductivity several thousand times the conductivity of still air, and far in'excess of the average conductivity of fluids, the heat travels between the fluids and the wall 1 much faster than it would if the beads were not present, notwithstanding the tortuous path of the heat from one bead to another and the slight thermal resistance encountered by the heat in passing from one bead to another and between the wall 1 and the adjacent bead. And this acceeleration or intensification of the heat transfer makes possible the use of a less eflicient and consequently stronger and less expensive wall '1 for a given efliciency of the apparatus.

In operation, the beads 5 offer some resistance to the flow of the fluid through the channels a, b, but this canbe reduced to a negligible quantity by suitably proportioning the beads themselves: that is, the larger the beads, the larger the interstices available for the passage of the fluid, and the lower the resistance offered-to the fluid. Thebeads serve-to break up the fluid into a large number of fine streams, so that all the parts of the fluid are brought into intimate thermal contact with a series of these particles of low thermal resistance, with the-result that the transfer of heat between the fluid and the particles or beads and through the beads to or from the dividing wall 1 and the other fluid, is materially accelerated or intensified, so that an effective heat transfer may be main tained even though the fluids A and B pass through thev apparatus at a comparatively high velocity; and the temperature gradient across the path of each fluid is maintained at a minimum, owing to the rapid equalization, through the metal beads, of any unbalanced heat distribution that might tend to occur. This, of course, increases the efiiciency of the apparatus by uniformly taking from or imparting to each portion of the fluid the same quantity of heat, without involving the use of unduly small conduits for the fluid.

While maintaining a rapid heat transfer across the path of the fluid, and equalizing the temperature of the various portions ofthe fluid at a given plane taken transversely to the axis or direction of flow of the fluid, as above described, it is likewise a feature of the present invention to prevent or minimize the transfer of heat along the path of flow of the fluid, that is, lengthwise or axially of the conduit. This is for the purpose of reventing the fluid portions that have attained a desired temperature, from losing that temperature by a conduction of heat between said portion and a portion which has not yet attained that temperature. For example, in the refrigeration of air, the air as it leaves a given stage of the apparatus is colder than the air entering the same stage of the apparatus, and any transfer of heat from the entering air to the air leaving the stage would raise the temperature of the latter and thus tend to reduce the efliciency of the apparatus, as by requiring the use of a greater number of stages to effect a given temperature drop in the air. In the resent invention, any heat transfer along tie path of the fluid is reduced to a negligible amount by the provision of layers of heat-insulating particles 7 at suitable intervals along the axis of the containers. These particles or beads are of a low thermal conductivity, and the spaces between the particles are sufliciently large to permit the passage of the fluid therethrough with out undue resistance. These heat-insulating beads neither aid nor hinder materially the transfer of heat to the walls of the conduit through the beads 5 of high thermal conductivity, since said transfer is effected at approximately right angles to the flow of the fluid. The insulating particles serve merely to greatly lessen or minimize the passage of heat energy axially of the container.

. In Figures 3 and 4, there is illustrated a modified construction in which the fluid A passes in one direction through a plurality of conduits 9 arranged within the container 2 in such manner that the fluid B may pass in the spaces between the inner wall of the container 2 and the outer'walls of the conduits 9. The channels through which the fluids flow are filled with heat-conducting beads 5, separated at intervals by layers of heat-insulating particles 7, as in Figures 1 and 2, and the operation of this embodiment of the invention otherwise corresponds generally to the above description of the operation of the ap paratus shown in Figures 1 and 2. By subdividing the fluid A in Figures 3 and 4, there is provided a greater conducting surface in the dividing walls between the two fluids, thereby permitting a more compactstructurc,

with attendant reduction of external radiafurther modification, of advantage particularly in connection with gases at comparatively high pressure. Here the fluid A is caused to pass through the series of

concentric coils

11, 12, 13 in a generally downward direction, while the fluid B, as before, flows upwardly in the spaces between the inner Walls of the outer container 2 and the outer walls of the

coils

11, 12, 13. By having the fluid A pass through coils instead of along a path parallel to the path of the fluid B, as in Figures 1, 2, 3 and 4, the fluid A travels a greater distance along its container for a given distance of travel axially of the flow of the fluid B. That is, in the preceding embodiments of theinvention, the fluid A in flowing one foot through its own container, would advance one foot along the path of travel of the fluid B, while in the apparatus shown in Figures 5 and 6, the fluid A must flow a number of feet through its

coils

11, 12 or 13, as the case may be, in order to advance one foot axially of the outer container 2. This permits a comparatively high velocity for the fluid through its coils for a given velocity axially of the outer container, and the higher velocity along the coils results in increased friction or eddy-currents, which tend to break up the fluid and bring all portions of it into frequent contact with the walls of the coils and thus increase the conduction of heat, with out the use of metal beads.

In this embodiment of the invention, the second fluid B flows at a lower pressure and at a lower velocity, so that the metal beads are provided to increase the heat conduction between this fluid B and the walls of the

coils

11, 12, 13. The larger cross-section, lower pressure and reduced agitation due to lower velocity of the fluid B would all tend to hinder the rapid transfer of heat unless the solid particles were utilized, and conversely, the use of the solid particles does not have the resisting effect on the fluid fiow'that would occur if the fluid B were operated at higher velocity through a smaller cross-section.

In using this

apparatus ofFigures

5 and 6 for obtaining low temperatures, an advantags is found in that the comparatively high velocity of the fluid A through the coil-i 11,

12, 13, reduces or prevents stoppages of the apparatus due to particles of frost, such as water vapor, carbonic acid, or other impuri-' ties, which an intensely cooled gas usually carries, and which at a slow fluid velocity tend to adhere to the walls of the coils. The fluid B is assumed to be substantially free from the impurities which would occasion the formation of frost, and hence this latter fluid may be operated at a lower velocity.

A further modification is illustrated in Figures 7 and 8 of the drawings, where the two fluids A and B are caused to flow cross- Wise of one another in what may be termed a cross-current apparatus. In this embodiment of the invention the fluid A passes through coils 15 arranged in the form of a cylinder of large diameter compared with the diameter of the pipe or tube of which the coil is formed. This cylinder is placed within a conduit 16 of annular cross-section, comprising the inner wall 18 and the outer Wall l9.- Owing tothe ratio of diameters of cylinder tube, the fluid A travels through the apparatus in an approximately horizontal direction, and thus encounters at substantially right angles the vertically traveling fluid B. If this type of apparatus is used for lowtemperature work, the space within the inner wall 18 may be used to house the container of a low-temperature liquefied gas or apparatus for the separation of its constituents, since this inner space is effectively protected from the temperature of outside air by the annular conduit 16, and the fluid undergoing heat exchange therein, it being noted that the outer cylindrical wall 19 may be insulated as is shown in Fig. 1.

v In the above description,it is to be understood that the apparatus and method of the present invention-may be utilized in a variety of ways, as in high or low-temperature work,-

and in fact in many if not all of the situations Where an effective transfer of heat is desir able.

In view of the above, it is believed that the various features of this invention will be above set forth, it is to be understood that.

all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus revealed my invention, 1

other advantageous claim and desire to secure by Letters Patent of the United States:

In apparatus of the class described, in combination, a plurality of coils for a fluid, ar-

ranged concentrically with respect to each other, a container surrounding the coils and means for insulating from one another the arranged for the passage of a second fluid beads at points along the path of said second 10 between the inner wall of the container and fluid, to reduce the transfer of heat along the the outer walls of the coils, beads or particles path of said second fluid.

5 of high thermal conductivity arranged to In testimony whereof, I have signed my contact intimately with said second fluid, to name to this specification this 13th day of facilitate the transfer of heat between said October, 1916. coils and all portions of said second fluid, and RUDOLPH VUILLEUMIER.