US1844308A - Heat exchanger - Google Patents

Description

Feb. 9, 1932. w. H. ARMACOST HEAT EXCHANGER Filed March 9. 1927 INVENTORQ W/LBuR H ARM/16057? ATTORNEY iatentecl Feb. 9, 1932 UNITED STATES PATENT OFFICE WILBUR H. ARLLACOS'I', OF NEW YORK, N. Y., ASSIGNOR TO THE SUPERHEAT'ER COM- PANY, OF NEW YORK, N. Y. j

HEAT EXGHANGER Application filed March 9, 1927. Serial No. 173,904.

go called standard dimensions. These types of structures are further often designed for service wherein the operating conditions may be materially changed after the unit is placed in service. For example, in the case of boilers and oil stills, the type of fuel used may be changed, and in the case ofstills and chemical apparatus the character of the liquid to be heated or cooled may vary within wide limits. The present invention has for its principal object the provision of a form of heat ex changer which will enable widely varying operating conditions to be met by a structure of standard form and dimensions. further object is the provision of a form of heat exchanger which after being assembled may have its characteristics so altered that it may be rendered suitable for operating conditions other than those for which it was originally designed. More specifically, the object of the invention is the provision of apparatus in which a plurality of heat exchange tubes are placed in the confined path of a heat absorbing or rejecting fluid in such a manner that the free flow area for said fluid, and consequently its velocity, may be varied in any given passage. A still further object of the invention is the accomplishment of the above objects by the use of heat exchange elements of a type wherein the free flow area past such elements through any given passage may be varied by the rotation ofsaid elements around their longitudinal axes. Further and more detailed objects of the invention together with the advantages to be derived from its use will become apparent from a perusal of the ensuing detailed description of preferred embodiments of the invention which I have illustrated in the accompanying diagrammatic drawings, in

which Figs. 1a, 1b, and 1c are transverse sections taken through the same apparatus in different positions. Fig. 2 is a longitudinal section taken through one form of apparatus embodying the invention, Fig. 3 is a section similar to Fig. 2 showing apparatus embodying another form of the invention, and Fig. 4 is a fragmentary elevation on an enlarged scale of part of the structure shown in Fig. 3., Referring now to Fig. 1a, I have shown diagrammatically a passage 1, defined by walls 2, and adapted to convey absorbing or rejecting fluid in either of the directions indicated by the arrow in the figure.

Located transversely of the flow of fluid through passage 1 are a plurality of fluid carrying elements, each of which comprises a plurality of individual pipes 3 which are joined at their ends to form single end portions 4, the latter being secured in suitable headers, connected by return bends.

The specific arrangement of these elements with respect to their spacing in rows, etc.,

A may be widely varied within the scope of the invention, but for purposes of illustration I have shown these elements arranged in horizontal rows, with the elements staggered with respect to each other vertically. In Fig. 1a I have shown the elements arranged with the individual pipes 3 set horizontally with respect to each other in the individual units, and it will be readily apparent from the figure that with this arrangement, the minimum free flow area is provided for the fluid passing these elements. In Fig. 1?) I have shown the same apparatus with the elements rotatedabout their longitudinal axis substantially 45' deg. from the position shown in Fig. 1a, and

it will be evident that with this arrangement the free flow 'area round these elements through passage 1 has been materially in creased. In Fig. 10 the same apparatus is shown with the elements rotated 90 deg. from the position shown in Fig. 1a, and it will be seen that in this position the maximumfree flow area is-provided past the elements. It will further be apparent that this change in the free flow area through the passage 1 is eflected without in any way necessitating a change in the structure of the apparatus as a ably spherical or conical.

to the maximum, as established by the position of the elements in Fig. 10, merely by the rotation of the elements about their longitudinal axes.

While I have shown, for purposes of illus tration, elements having the minimum number of individual pipes, and with the pipes of the same diameter, it will be readily apparent to those skilled in the art that ele ments having three or more individual pipes, of the same or different diameters, joined to form single end sections may be utilized in precisely the same manner as the elements herein illustrated.

In Fig. 2 I have shown a section taken longitudinally of the elements, inwhich the passage 1 is defined by the side walls 2 and headers 80. The flow of fluid through the passage 1 is at right angles to the plane of the paper, and in this instance the units are formed with single cylindrical ends 4 adapted to be rolled or otherwise suitably secured in the inner walls 5 of headers 30, the latter being provided with suitable handholes or cover plates 6. With the element ends formed in this manner the apparatus is not adapted to be changed readily after having been originally assembled, but-the invention enables 'an apparatus of this character and of a certain standard size to be adapted to various types of service, because of the various positions in which the elements may be initially set.

In Fig. 3 I have shown the apparatus, in a section similar to Fig. 2, constructed in a form suitable for change or adjustment of the units after the apparatus as a whole has beenassembled. In this form the element ends 4 are provided at their ends w1th upset or other suitably formed rings 7, the latter being ground to form suitable seats, prefer- Header boxes 8 seat against rings 7 and are held in place by means of the studs 10, which pass through suitable bosses on the header boxes and are screwed into ears formed on the clamp rings 9 which seat against the opposite faces of rings 7.

It will be evident from an inspection of the figure that by simply loosening the connections between the header boxes 8 and the element ends 4 that the elements may be freely rotated to any desired position and then again clamped in position between the header boxes to secure the necessary fluid-tight joints. While in Fig. 2 I have shown the .elements permanently secured in headers imposing parallel flow through the elements, and in Fig. 3 I have shown the elements adjustably mounted between header boxes imposing series flow through the tubes, 1t is to be understood that the manner of securing the elements, that is, either permanently or adjustably, is not in any way dependent upon the manner in which the elements may be assembled with respect to the fluid flow therethrough. It is to be noted, however, that the type of end joint shown in Fig. 3 is not well suited for use in connection with headers receiving a large number of tubes, such as headers 30 in Fig. 2, for if the a'd'ustable type of element is used between such eaders, it will be apparent that all of the elements joining any two headers must be of exactly the same finished overall length if tight joints are to be secured, and that an une ual expansion of elements between sucfi hea ers would tend to produce leaky joints. For these reasons, I prefer to use individual header boxes such as those shown at 8 in Fig. 3, at least at one end of the elements, as far as possible Where the adjustable type of element is used.

As mentioned above, this type of structure is particularly adaptable for use in boilers, oil stills and similar apparatus where the fluid carried by the elements is under high pressure, and for this reason, I prefer to use forging process shown in Patent No.

1,169,209issued January 25, 1916, to C. H. True and N. T. McKee, followed by the initial steps of the process shown in Patent No. 1,155',110 issued September 28, 1915, to the same inventors. The end sections 4 of the elements may, however, equally well be made by welding or, in cases where the elements are not to be subjected to extreme internal pressures, the elements may, if desired, be built up by the use of individual pipes threaded or otherwise suitably secured in Y fittings, the bottom portions of which may be extended and either expanded into suitable headers or formed with suitable end seats for the purpose of adjustable clamping.

From the foregoing description it will be apparent that the present invention may be applied in a wide variety of specific forms and arrangements. The illustrative examples of the invention herein disclosed are. therefore,-to be taken as illustrative only and not limitin in sense, and the scope of the invention is to e limited only by that of the appended claims.

I claim:

1. In apparatus of the class described, the

. combination with a passage adapted to conments comprising endv sections symmetrical with respect to the longitudinal axis of the element and an intermediate section connect- .ing said end sections, said intermediate section comprising a plurality of pipes, fluid conveying members connected by said ele ments, and means for detachablysecuring said elementsto said members.

2. In apparatus of the class described, the combination with a passage adapted to convey a heat absorbing or rejecting fluid, of a plurality of heat exchanging elements disposed transversely of said passage, each of said elements comprisin end sections symmetrical With respect to tile longitudinal axis of the element and an intermediate section connecting said end sections, said intermediate section comprising a pair of spaced parallel pipes, fluid conveying members connected by said elements, and means detachably securing said elements to said members.

3. In apparatus of the class described, the combination with a passage adapted to convey a heat absorbing or rejecting fluid, of a plurality of integral heat exchanging elements arranged transversely of said passage, each of said elements comprising single cylindrical end sections and an intermediate section formed by a plurality of pipes, each of said end sections having formed thereon a greatest free flow area to the general line of fluid flow through said passage to provide less than the greatest free flow area through the passage past the elements.

6. Apparatus ofthe character described comprising, in combination, means providing a passage for flow of a heat absorbing or re! jecting fluid, a plurality of rows of heat exchange elements disposed transversely of sald passage each of said elements comprising coaxial end sections of circular cross-section and an intermediate section comprising a pair of spaced parallel pipe portions connecting said end sections, the elements of the several rows being staggered with respect to the general line of fluid flow through the passage and fluid conveying members connected by said elements, said end sections being secured to said members in positions such that planes passing through the center lines of the pairs of pipe portions of the elements lie at an angle to said general line of fluid flow through the passage to provide less than the through the passage past the elements.

. WILBUR H. ARMACOST.

circular seat, fluid conveying members connected by said elements and having openings therein adapted to receive said seats, and means .for removably securing said elements to said members.

4. In apparatus of the class described, the

i combination With a passage adapted to convey a heat absorbing or rejecting fluid, of a plurality of hollow heat exchanging elements located in said passage and adapted to withstand internal pressure without distortion, said elements being formed entirely by Walls the opposite sides of which are exposed to different fluids, the form and arrangement of said elements being such that the free'flow area through said passage past said elements is varied by the changes in position of said elements efiected by rotation of the elements about their longitudinal axes, fluid conveying members connected by said elements, and releasable means for securing said elements to said members to permit rotation of the elements.

5. Apparatus of the character described comprising, in combination, means providing a passage for flow of a heat absorbing or rejecting fluid, a plurality ofheat exchange elements disposed transversely of said passage, each of said elements comprising co-axial end sections of circular cross-section and an intermediate section comprising a pair of spaced parallel pipe portions of circular cross-section connecting said end sections, and fluid conveying members connected by said elements, said end sections being secured to said members in positions such that planes passing through the center lines of the pairs of pipe portions of the elements lie at an angle

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