US3263314A

US3263314A - Fixture for and method of assembling heat exchanger core

Info

Publication number: US3263314A
Application number: US285663A
Authority: US
Inventors: Paul J Smeltzer; David D Jordan
Original assignee: Bendix Corp
Current assignee: Bendix Corp
Priority date: 1963-06-05
Filing date: 1963-06-05
Publication date: 1966-08-02
Anticipated expiration: 1983-08-02
Also published as: GB1005630A

Description

Aug. 2, 1966 J, SMELTZER ET AL 3,263,314

FIXTURE FOR AND METHOD OF ASSEMBLING HEAT EXCHANGER CORE Filed June 5, l 63 2 Sheets-Sheet 1 INVENTOR.

DAVID D. JORDAN PAUL J. SMELTZER.

AGENT.

Aug. 2, 1966 p. SMELTZER ET AL 3,263,314-

FIXTURE FOR AND METHOD OF ASSEMBLING HEAT EXCHANGER CORE Filed June 5, 1963 2 Sheets-Shed 2- l N VEN'TOR.

DAVID. 0. JORDAN.

1 PA 21L .1. SMELTZER.

AGENT.

United States Patent 3,263,314 FIXTURE FOR AND METHOD OF ASSEMBLING HEAT EXCHANGER CORE Paui J. Smeltzer, Pittsburgh, Pa., and David D. Jordan, South Bend, Ind., assignors to The Bendix Corporation, South Bend, Ind., a corporation of Delaware Filed June 5, 1963, Ser. No. 285,663 4 Claims. ((11. 29-1573) This invention relates, in general, to assembly fixtures and, in particular, to a fixture for assembling a compartmentized pellet tube type heat exchanger core.

The assembly of a heat exchanger core having compartments filled with a pellet matrix presents a problem in that the various compartments through which the tubes extend must be completely filled with pellet material which, heretofore, has been accomplished by pouring the pellets into each compartment from an open end thereof before the component sections of the core are inserted in position to define the adjacent compartment. Such an arrangement is disadvantageous in that the assembly time of the heat exchanger core is high with corresponding high labor costs and the quantity of pellets poured into each compartment must be carefully controlled to permit proper positioning of the various component sections of the heat exchanger core.

It is therefore an object of the present invention to provide a fixture for easy and quick assembly of a compartmentized pellet tube type heat exchanger core.

It is another object of the present invention to provide a fixture for a compartmentized pellet tube type heat exchanger core whereby the various compartments thereof are filled with the pellet material through a separate access portion communicating with each of the compartments.

It is still another object of the present invention to provide a fixture for a compartmentized pellet tube type heat exchanger core whereby the pellet material is introduced into the various compartments thereof subsequent to the assembly of the various component sections of the core which together with the fixture define the various compartments.

Other objects and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein:

FIGURE 1 is a plan view of the present invention;

FIGURE 2 is a sectional view taken on line 22 of FIGURE 1 showing the compartmentized pellet tube type heat exchanger core as assembled within the fixture;

FIGURE 3 is a view of the two halves of the fixture in separated form;

FIGURE 4 is a sectional view taken on line 4-4 of FIGURE 1;

FIGURE 5 is a sectional view taken on line 5-5 of FIGURE 1;

FIGURE 6 is a sectional View taken on line 6--6 of FIGURE 1; and

FIGURE 7 is a view of the assembled compartmentized pellet tube type heat exchanger core removed from the fixture.

Referring to the drawings, numeral 20 designates generally an assembly fixture of cylindrical shape having two

semicylindrical portions

22 and 24 which are provided with spaced apart

lugs

26 and 28, respectively, fixedly secured thereto. Each lug 26 has a bore 30 and a counterbore 32 adapted to receive a locking pin 34 having a flanged portion 36 which is urged into engagement with lug 26 by a screw member 38 threadedly engaged with one end of pin 34. The locking pin 34 is provided with a plurality of circumferentially spaced apart flutes 48 3,263,314 Patented August 2, 1966 which are slidably carried by a bore 42 in lug 28. The

lugs

26 and 28 are secured together by a wedge shaped member 44 provided with a slot 46 adapted to receive a reduced diameter section 48 of locking pin 34, which member 44 is forced into position as shown in FIGURE 5 to thereby force lug 28 into locked engagement with lug 26.

A circular end plate 51) is held in clamped engagement with one end of the

semicylindrical portions

22 and 24 by means of locking pins 52 which extend through bores 54 in diametrically opposed lugs 56 fixedly secured to

portions

22 and 24. The locking pins 52 extend through openings 58 in end plate 50 and are provided with reduced diameter portions 60 which are received by slots 62 in associated wedge shaped members 64 which are forced into position as shown in FIGURE 2 to thereby force plate 50 into locked engagement with lugs 56. Referring to FIGURES 2 and 4, the end plate 50 is provided with a plurality of locating pins 66 fixedly secured thereto in circumferentially spaced apart relationship which extend a predetermined distance longitudinally inwardly of the

semicylindrical portions

22 and 24 for a purpose to be explained. A plurality of concentric annular rings 68 integral to end plate 50 extend therefrom a predetermined distance longitudinally inwardly of the

semicylindrical portions

22 and 24 for a purpose to be explained. A plurality of fluid access ports 76 located in the recesses defined by adjacent annular rings 68 extend through end plate 50 and permit fluid flow into and out of the recesses during a brazing operation to be described. Also, fluid access ports 71 and 72 are provided in opposite end sections of portion 28 to permit fluid flow into and out of the interior of fixture 20 during the brazing operation.

A circular end plate 73 located at the opposite end of

semicylindrical portions

22 and 24 is held in position within the inner walls of the

portions

22 and 24 by a pair of diametrically opposed retaining members 74 secured to

portions

22 and 24 by bolts 76 threadedly engaged therewith.

A support hook '78 is attached to a curved flexible bracket 80 having openings 82 at opposite end portions thereof adapted to receive pins 84 fixedly secured to

semicylindrical portions

22 and 24. A spring 86 interposed between the end plate 73 and a retaining pin 88 fixedly secured to hook 78 serves to load end plate 73.

The semicylindrical portion 24 is provided with a plurality of spaced apart boss portions 96 which are bored to provide circular loading ports 92 having a counterbore 94. Each port 92 is adapted to receive a plug 96 having a curved end portion 98 which conforms to the curvature of the inner wall of portion 24 and a flanged section 100 which fits into counterbore 94. A pair of diametrically opposed locating pins 102 are fixedly secured to flanged section 100 and extend therefrom into slots 104 formed in boss portions 90 to thereby locate plug 96 such that the curved end portion 98 is aligned circumferentially with the inner curved wall of portion 24. The plugs 96 are locked in position by overlapping retaining plates 106 secured to boss portions 90 by bolts 188.

The heat exchanger core generally indicated by numeral 110 includes an outlet end plate 112 provided with a plurality of spaced apart openings 114 through which extend a plurality of longitudinally extending tubes 116. The opposite inlet end of the core 111 is provided with an inlet end plate 118 which is provided with a plurality of openings 120 through which the tube 116 extends. Spaced apart

circular baflles

122 and 124 are provided with extruded openings 126 through which the tubes 116 extend. The

baffles

122 and 124 are maintained in spaced apart relationship relative to

end plates

112 and 118, respectively, as well as to one another by pairs of longitudinally extending perforated V-shaped sheet metal plates 128 which are located radially outwardly from the tubes 116. The adjacent parallel edges of each pair of plates 128 are spaced circumferentially apart thereby partially defining rectangular openings 130 through which a pellet matrix 132 may be introduced to fill chambers 134 partially defined by each pair of plates 128.

Battles

122 and 124 are severed to conform to one of the V-shaped plates 128 abutting thereagainst thereby providing an opening 136 through which fluid may flow between adjacent chambers 134. The various sections including the pellet matrix 132 of the heat exchanger core 110 are coated with a suitable brazing material which under the application of heat flows around adjacent contacting surfaces of the core 110 thereby providing a unitized structure.

The heat exchanger core 110 is assembled within the fixture 20 in the following manner. The fixture 20 is partially assembled by placing the

semicylindrical portions

22 and 24 together with pins 34 extending through the respective openings 42 and lugs 28. The wedge shaped members 44 are driven into position on reduced diameter sections 48 to thereby lock the

portions

22 and 24 together. The end plate 50 is attached to the one end of

portions

22 and 24 by inserting locking pins 52 through bores 54in lugs 56 and openings 58 in plate 50 and driving wedge shaped members 64 into position on reduced diameter sections 60 to thereby lock end plate 50 securely in position. The assembled

portions

22 and 24 and end plate 50 are placed upright on end plate 50. The end plate 112 is placed within the

portions

22 and 24 where it rests against locating pins 66. The two outermost rows of tubes 116 against which the plates 128 bear are inserted into the two outermost rows of openings 114 and end plate 50. A plate 128 is inserted between each of the two outermost rows of tubes 116 and the adjacent inner wall defined by

portions

22 and 24 with one end of each plate 1'28 bearing against end plate 50. The two outermost rows of tubes 116 are inserted through the corresponding openings 126 of baflle 122 which is pushed longitudinally along tubes 116 into engagement with the ends of the pair of plates 128 therebelow. A second pair of plates 128 is inserted between the two rows of tubes 116 and the adjacent

inner wall portions

122 and 124 with one end of each plate bearing against the upper surface of bafile 122. The tubes 116 are inserted through corresponding openings 126 of baffle 124 which is located with its severed portion which defines opening 136 one hundred and eighty degrees out of alignment with the corresponding severed portion of baffle 122. The baffle 124 is pushed longitudinally along the tubes 116 into engagement with the ends of the second pair of plates 128 therebelow. A third pair of plates 128 is inserted between tubes 116 and the inner wall defined by port-

ions

22 and 24 with the ends thereof bearing against the upper surface of batfle 124. The tubes 116 are inserted through corresponding openings 120 and end plate 118 which is urged into engagement with the ends of plates 128 therebelow. The remaining tubes 116 are inserted through corresponding openings 120- in end plate 118 and pushed longitudinally through corresponding openings in

baflles

122 and 124 and end plate 112 into position with the ends thereof abutting annular rings 68 in end plate 50. The end plate 73 is inserted in position against end plate 118 and retaining members 74 locked in position to retain end plates 73. It will be noted that the rectangular openings 130 partially defined by adjacent parallel edges of each pair of plates 128 are aligned with associated loading ports 92 through which the pellet matrix 132 is introduced to fill chambers 134. Also, as shown in FIGURE 2, the tubes 116 are located longitudinally relative to the

end plates

112 and 118 by the annular rings 68 which contact the ends of tubes 116 such that the outlet ends of the tubes 116 extend slightly below the end plate 112 and the inlet end of tubes 116 are substantially flush with the one side of end plate 118. It will be understood that the various component sections which make up the assembled fixture 20 may be made of any suitable metal. However, applicants have found that stainless steel is well suited for such use in which case the fixture is oxidized to prevent the adherence of brazing material to the fixture 20 during the brazing operation whereby the parts of the heat exchanger core are unitized. The fixture 20 is positioned horizontally with loading ports 92 facing upward and the pellet matrix 132 poured through each of the ports 92 to fill the chambers 134. The filling of chambers 134 is facilitated by attaching suitable vibrating mechanism, not shown, to the fixture 20 which agitates the same to promote the flow of pellet matrix around the tubes 116 and within chambers 134 thereby completely filling chambers 134 with pellet matrix. The pellet matrix 132 is allowed to partially fill the ports 92. Each plug 96 is positioned in its respective loading port 92 with pins 102 aligned with slots 104 and pushed inwardly to compress the pellet matrix 132 and allow pins 102 to engage slots 104. Each plug 96 is locked in position by its associated retaining plate 106 which is secured by tightening bolts 108. In the locked position the curved end portion 98 of each plug 96 extends inwardly from the inner wall of portion 28 a slight distance 'to insure that the pellet matrix 132 in the region of ports 92 does not extend radially outwardly beyond the inner wall of portion 28.

The support hook 78 is secured to the above described assembled fixture 20 by temporarily spreading the bracket to enable pins 84 to engage openings 82.

The fixture 20 containing the assembled heat exchanger core 110 is subjected to a conventional brazing process which includes immersing the same in a heated flux bath for a predetermined period of time to permit flux to flow through ports 71 and 72 into the interior of fixture 20 thereby causing the brazing material on the heat exchanger core 11a to flow and join the component sections at the adjacent contacting surfaces thereof. The fixture 20 and core 110 is subsequently removed from the flux bath and the flux drained and rinsed theretfrom. Finally, the bracket 80 and

end plates

50 and 72 are detached from

semicylindrical portions

22 and 24 and Wedge shaped

members

44 and 64 disengaged from

pins

34 and 52, respectively, to permit separation of the

semicylindrical portions

22 and 24 and removal of the unitized heat exchanger core 110. The locking pins 34 are provided with the flutes 40 to reduce the eflective engagement area of pins 34 and associated bores 42 thereby reducing the tendency for pins 34 to adhere to lugs 44 due to brazing material lodging therebetween.

The heat exchanger core 110 is adapted for insertion in a heat exchanger casing, not shown, having an inner diameter equivalent to the inner diameter of fixture 20. The outermost edge of end plate 112 is adapted to engage an O-ring seal, not shown, carried by the heat exchanger casing inner wall which O-ring provides a fluid seal. An O-ring seal, not shown, carried in a recess 138 in end plate 118 is adapted to engage the inner wall of the heat exchanger casing to thereby provide a fluid seal. The heat exchanger casing, not shown, is provided with inlet and outlet ports which direct a first fluid to and away from core 110 in the direction shown by the arrows labeled In and Out in FIGURE 7. The openings 136 in

bafiles

122 and 124 direct the first fluid in a tortuous path from one end of core 110 to the opposite end thereof as indicated by the remaining arrows. Also, the heat exchanger casing, not shown, is provided with inlet and outlet conduits which direct a second fluid to and away rfrom tubes 116 through which the second fluid flows. The first fluid may be the cooling medium and the second fluid may be the medium to be cooled, or the first fluid the medium to be cooled and the second fluid the cooling medium depending upon the direction of heat transferdesired.

It will be understood that various changes and modifications in the structure shown and described may be made by those persons skilled in the art without departing from the spirit of the present invention. For instance, the fixture is not restricted to cylindrical shaped heat exchanger cores and may be readily adapted for use with heat exchanger cores of various other shapes.

We claim:

1. A fixture for assembling a heat exchanger core having a first fluid conducting compartment therein which is filled with pellet material and a plurality of tubes which extend through the compartment for conducting a second fluid through the core, said fixture comprising:

a two part housing having first and second portions removably secured together,

a first end plate removably secured to one end of said first and second portions,

a second end plate removably secured to the opposite end of said first and second portions,

said heat exchanger core being held in assembled position within said housing by said first and second end plates,

a loading port formed in the sidewall of one of said first and second portions for introducing pellet material into the compartment of said core to fill the same, and

a plug removably secured to said loading port for retaining said pellet material in the compartment during a brazing operation whereby the component sections including said pellet material of said heat exchanger core are unitized,

said first and second end plates and said first and second portions being disassembled after the brazing operation to permit removal of the unitized heat exchanger core.

2. A fixture for assembling a heat exchanger core having a plurality of spaced apart baflles and end plates through which a plurality of spaced apart tubes extend, said bafiles and end plates being separated by a plurality of spacing members and partially defining a plurality of compartments adapted to be filled with pellet material, said fixture comprising:

a two part housing having first and second semicylindrical portions adapted to be removably secured together,

a first end plate removably secured to one end of said first and second portions to close the same,

said two part housing being up ended with its opposite open end up to permit insertion of said end plates, spacing members, bafiles and tubes in predetermined position relative to one another therein,

a second end plate removably secured to said opposite open end to close the same and hold the assembled end plates, spacing members and bafiles in spaced apart position longitudinally within said two part housing,

a separate loading port formed in the sidewall of one of said first and second semicylindrical portions and communicating with each of the plurality of compartments for introducing pellet material therein,

a plug removably secured in each of said loading ports for retaining the pellet material in the associated compartments during a brazing operation whereby the component sections including said pellet material are unitized,

said first and second semicylindrical portions and said first and second end plates being disassembled after the brazing operation to permit removal of the unitized heat exchanger core.

3. A method of making a tube type brazed heat exchanger core having end plates and bafiies intermediate thereof through which a plurality of tubes extend and which define a plurality of compartments adapted to be filled with pellet material comprising the steps of:

providing a fixture having a two part housing removably secured together to form a cavity closed at one end by an end plate removably secured to the two part 6 housing and provided with a plurality of loading ports formed in the sidewall thereof,

placing the two part housing upright on the closed end thereof,

inserting a first end plate of said core in position within said two part housing and inserting one end of the plurality of tubes in spaced apart openings formed in said first end plate,

inserting spacing members and bafiles spaced apart by said spacing members in order longitudinally within said two part housing to define the plurality of compartments separated by said baflles and communieating with said loading ports,

inserting a second end plate of said core having spaced apart openings therein which receive the opposite end of said plurality of tubes in position within said two part housing,

inserting an end plate in position against said second end plate and locking the same in position to thereby retain said first and second end plates and spacing members and bafiles intermediate said first and second end plates in spaced apart relationship,

placing said two part housing on a side thereof with the loading ports the-rein facing upward,

pouring pellet material through each of said loading ports to fill the chamber communicating therewith, inserting plugs in said loading ports to retain the pellet material within the chambers, subjecting the fixture which is coated with a material to prevent adherence of brazing material thereto and the heat exchanger core which is coated with a brazing material to a brazing operation whereby the component sections of the heat exchanger core are brazed together to form a unitized heat exchanger core, and

disassembling the two part housing and end plate secured thereto to permit removal of the unitized heat exchanger core therefrom.

4. A method of making a tube type brazed heat exchanger core having end plates and battles intermediate the end plates through which a plurality of spaced apart tubes extend and which define a plurality of compartments adapted to be filled with pellet material comprising the steps of:

providing a fixture having a two part housing removably secured together to form a cylindrical cavity closed at one end by an end plate removably secured to the two part housing and provided with a plurality of spaced apart loading ports in the sidewall of the two part housing,

inserting a first end plate of the core in said two part housing in position against a plurality of locating pins extending from said end plate secured to said two part housing, inserting one end of the plurality of tubes into associated spaced apart openings in said first end plate,

inserting the spacing members and bafiles spaced apart by the spacing members in order longitudinally along said plurality of tubes within said two part housing to define the plurality of compartments separated by said baffles and communicating with said plurality of loading ports,

inserting a second end plate of the core having spaced apart openings therein adapted to receive the opposite end of said plurality of tubes in position within said two part housing,

inserting an end plate in position against said second end plate and locking the same in position to thereby retain said first and second end plates, spacing members and bafiles in spaced apart relationship within said two part housing,

placing said two part housing on a side thereof with the loading ports therein facing upward,

pouring pellet material through each of said loading ports to fill the compartment communicating therewith,

7 8 inserting a plug in each of said loading ports to retain cured thereto to permit removal of the unitized heat the pellet material within the associated compartexchanger core therefrom. ment, References Cited by the Examiner subjecting the fixture which is coated with a material to prevent adherence of brazing material thereto and 5 UNITED STATES PATENTS the heat exchanger core which is coated with a braz- 2,242,985 5/ 1941 Feuneft 24996 ing material to a brazing operation whereby said 214011797 6/1946 Rasmussenfirst and second end plates, baffles, spacing members, 2,443,574 6/1948 Burnstubes and pellet material are brazed together to form 2686957 8/1954 Koerper' a unitized heat exchanger core, and 10 WHITMORE A. WILTZ, Primary Examiner. disassembling the two part housing and end plates se- J D, HOBART, E i

Claims

3. A METHOD OF MAKING A TUBE TYPE BRAZED HEAT EXCHANGER CORE HAVING END PLATES AND BAFFLES INTERMEDIATE THEREOF THROUGH WHICH A PLURALITY OF TUBES EXTEND AND WHICH DEFINE A PLURALITY OF COMPARTMENTS ADAPTED TO BE FILLED WITH PELLET MATERIAL COMPRISING THE STEPS OF: PROVIDING A FIXTURE HAVING A TWO PART HOUSING REMOVABLY SECURED TOGETHER TO FORM A CAVITY CLOSED AT ONE END BY AN END PLATE REMOVABLY SECURED TO THE TWO PART HOUSING AND PROVIDED WITH A PLURALITY OF LOADING PORTS FORMED IN THE SIDEWALL THEREOF, PLACING THE TWO PART HOUSING UPRIGHT ON THE CLOSED END THEREOF, INSERTING A FIRST END PLATE OF SAID CORE IN POSITION WITHIN SAID TWO PART HOUSING AND INSERTING ONE END OF THE PLURALITY OF TUBES IN SPACED APART OPENINGS FORMED IN SAID FIRST END PLATE, INSERTING SPACING MEMBERS AND BAFFLES SPACED APART BY SAID SPACING MEMBERS IN ORDER LONGITUDINALLY WITHIN SAID TWO PART HOUSING TO DEFINE THE PLURALITY OF COMPARTMENTS SEPARATED BY SAID BAFFLES AND COMMUNICATING WITH SAID LOADING PORTS, INSERTING A SECOND END PLATE OF SAID CORE HAVING SPACED APART OPENINGS THEREIN WHICH RECEIVE THE OPPOSITE END OF SAID PLURALITY OF TUBES IN POSITION WITHIN SAID TWO PART HOUSING, INSERTING AN END PLATE IN POSITION AGAINST SAID SECOND END PLATE AND LOCKING THE SAME IN POSITION TO THEREBY RETAIN SAID FIRST AND SECOND END PLATES AND SPACING MEMBERS AND BAFFLES INTERMEDIATE SAID FIRST AND SECONE END PLATES IN SPACED APART RELATIONSHIP, PLACING SAID TWO PART HOUSING ON A SIDE THEREOF WITH THE LOADING PORTS THEREIN FACING UPWARD, POURING PELLET MATERIAL THROUGH EACH OF SAID LOADING PORTS TO FILL THE CHAMBER COMMUNICATING THEREWITH, INSERTING PLUGS IN SAID LOADING PORTS TO RETAIN THE PELLET MATERIAL WITHIN THE CHAMBERS, SUBJECTING THE FIXTURE WHICH IS COATED WITH A MATERIAL TO PREVENT ADHERENCE OF BRAZING MATERIAL THERETO AND THE HEAT EXCHANGER CORE WHICH IS COATED WITH A BRAZING MATERIAL TO A BRAZING OPERATION WHEREBY THE COMPONENT SECTIONS OF THE HEAT EXCHANGER CORE ARE BRAZED TOGETHER TO FORM A UNITIZED HEAT EXCHANGER CORE, AND DISASSEMBLING THE TWO PART HOUSING AND END PLATE SECURED THERETO TO PERMIT REMOVAL OF THE UNITIZED HEAT EXCHANGER CORE THEREFROM.