Heat exchanger interplate fitting

An interplate inlet, outlet or other suitable fitting for use in a closely stacked plate heat exchanger which allows the placement of the fitting between the plates at any point along the length of the inlet or outlet header tank formed by the heat exchange plates. The fitting includes a pair of oppositely disposed facing substantially identical plates providing bubbles aligned with the bubbles at the ends of the heat exchanger plates and opening into a laterally extending conduit to be joined to a fluid hose or to receive appropriate fittings to receive a sensor or having internal threads to receive an externally threaded fitting.

BACKGROUND OF THE INVENTION 
Stacked plate heat exchangers made up of plates which form integral header 
tanks typically use inlet and outlet fittings which are attached to one 
end of each tank as shown in U.S. Pat. No. 3,207,216. This location is not 
always compatible with installation restraints, however, other fitting 
locations could not heretofore be utilized without introducing post-braze 
manufacturing operations; such operations comprising the cutting into the 
tanks and welding the fittings in place. 
SUMMARY OF THE INVENTION 
The present invention comprehends the location of inlet, outlet or other 
fittings at any desired position along the header tank formed by the 
stacking of plates to provide a closely stacked plate heat exchanger. The 
standard core plates forming the heat exchanger have an elongated 
generally flat or ribbed portion with a raised flange or bubble at each 
end having an enlarged opening therein. The central generally flat portion 
of each plate has a peripheral flange abutting a second facing plate to 
provide an enclosed passage, and the oppositely extending bubbles at each 
end abut the bubbles of adjacent plates with the openings aligned to 
provide enlarged header tanks at the opposite ends of the heat exchanger. 
To permit insertion of a fitting having its own bubble, the abutting 
bubble halves of two adjacent plates are omitted and the fitting bubble 
inserted to form a portion of the header tank. 
The present invention also comprehends the provision of a novel fitting 
that is formed of two generally symmetrical halves having a bubble portion 
that enlarges into a semi-cylindrical half of a conduit or fitting 
portion. As the fitting halves are formed of sheet material in the same 
manner as the core plates, the entire assembly may be stacked together and 
brazed; thus eliminating any post braze manufacturing operation. 
The present invention further comprehends the provision of a fitting to be 
inserted as an integral portion of a header tank wherein the fitting may 
form an inlet or outlet conduit to be appropriately attached to hoses or 
tubing, or the fitting can be provided with suitable adapters to provide 
an internally threaded connection or a friction fit connection to receive 
a sensor, flow gauge or other appropriate member. 
Further objects are to provide a construction of maximum simplicity, 
efficiency, economy and ease of installation and operation, and such 
further objects, advantages and capabilities as will later more fully 
appear and are inherently possessed thereby.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring more particularly to the disclosure in the drawings wherein is 
shown an illustrative embodiment of the present invention, FIG. 1 
discloses a closely stacked plate, cross flow, heat exchanger 10, such as 
used for an automobile radiator, including a plurality of heat exchange 
plates 12 having enlarged portions at the opposite ends thereof to form 
inlet and outlet header tanks 13 and 14. Each plate is formed of a pair of 
facing dished members 15,15 bonded together along their peripheral edges 
16,16 and provided with raised portions or bubbles 17,17 or 18,18 at the 
opposite ends having oppositely disposed enlarged openings 19 therein; the 
oppositely disposed bubbles 17,17 or 18,18 combining to form the enlarged 
header tank portions 13 or 14, respectively. 
The pair of facing dished members 15,15 form an elongated flow passage 
extending between the bubbles 17,17 and 18,18, and the spacing 20 formed 
between the pairs of dished members provides for air flow between the flow 
passages and has a folded or corrugated metal heat transfer surface 21 
therein. The openings 19 in the bubbles 17 or 18 are axially aligned to 
provide a vertical flow passage through the header tank 13 or 14. 
The top plate 12a and the bottom plate 12b are each formed of a dished 
member 15 having opposite end bubbles 17 and 18 and a flat top plate 22 or 
bottom plate 23 bonded to the peripheral edge 16 of the respective dished 
member 15. An inlet fitting 24 adapted to be connected to a suitable hose 
or conduit is bonded onto the top plate 22 and communicates with an 
opening in the plate (not shown) axially aligned with the header tank 13. 
An outlet fitting 25 is provided in the header tank 14 at a point 
intermediate the ends thereof of a construction to be later described. A 
pressure fitting 26 may be secured to the upper flat plate 22 at an 
opening generally aligned with the header tank 14 and has an overflow 
fitting 27 thereon; the fitting receiving a suitable pressure cap (not 
shown). Suitable support members (not shown) may be inserted into the 
assembly to provide a means of mounting a fan shroud or electric fan 
assembly onto the heat exchanger. 
To allow for the insertion of the fitting 25 into the stacked plate 
assembly, a pair of modified heat exchange plates 29,29 are utilized with 
each plate being a combination of a dished member 15 and a dished member 
31 having a peripheral edge 32 with a bubble 33 at one end and an enlarged 
opening 34 at the opposite end in the flat surface 35 of the dished member 
31. In the instance of the fitting 25, the bubbles 33,33 at the one end of 
the two plates members 31,31 abut and are joined together with the 
openings therefor axially aligned with header tank 13, and the oppositely 
facing peripheral edges 31,31 are joined to the edges 16 of the adjacent 
dished members 15,15 to complete the flow passages of these two plates for 
the header tank 13. The openings 34,34 in flat surfaces 35,35 of the 
plates 31,31 are axially aligned with the openings in the bubbles 18 for 
the header tank 14. 
The fitting 25 is formed of a pair of substantially identical plates 36,36, 
although modified plates may be used as shown in FIG. 10, the plates 
facing each other with abutting peripheral flanges 37,37 and oppositely 
disposed bubbles 38,38 at one end of the plates. Each bubble has an 
opening 39 defined by a flange 41 arranged to extend into the opening 34 
of an adjacent 31 (see FIG. 4); the bubbles 38,38 and openings 39,39 
forming a portion of the header tank 14. The plates 36,36 extend 
rearwardly from the tank 14 and enlarge into a pair of facing 
semi-cylindrical members 42,42 joined by the peripheral flanges 37,37 to 
provide a conduit flange 43. A second fitting 44 vertically spaced from 
the fitting 25 is also formed of plates 36,36 and inserted into the header 
tank 14 through the use of additional plates 31,31. 
The fittings 25 and 44 can be utilized in a variety of ways depending on 
the type of insert received in the conduit flange 43. For instance, the 
fitting 44 has a tubular conduit member 45 received and brazed therein, 
the member 45 being cylindrical except for the annular embossment or 
enlarged bead 46 at the outer end over which a flexible hose 47 is slipped 
and secured by a suitable clamp (not shown). 
Another type of insert is a cylindrical ring or tube 48 inserted into and 
brazed in the flange 43 of the fitting 25 and having an internally 
threaded surface 49 adapted to receive an externally threaded plug or 
conduit. Thus, a threaded plug with a temperature sensor or other 
measuring device therein could be threaded into the ring 48 for 
measurement of a desired characteristic of the fluid flowing within the 
heat exchanger. A third fitting is an externally threaded plastic ring 51 
having a peripheral flange 52 at one end to abut the ring 48 and a reduced 
diameter smooth internal cylindrical surface 53 to receive an insert with 
a friction fit. 
As seen in FIG. 10, one or both of the two facing plates 36a may have two 
or more outwardly extending tabs 54 formed on the flange 37a at the 
semi-cylindrical portions 42a; the tabs 54 being folded over the flange 
37a of the facing plate 36a to retain the portions 42a, 42a together 
during brazing. Obviously the plates 36 could be formed as right and left 
handed or male and female to aid in positioning and/or joining the parts 
together to form the fitting. 
Obviously, the fitting 25 or 43 could be used on any position in either 
header tank 13 or 14 as either an inlet or outlet fitting or to sealingly 
receive a member therein for any suitable function, such as measuring flow 
or temperature of the fluid or to communicate with a feeder for an 
additive for the fluid therein. When the heat exchanger, is assembled with 
the dished members 15, top plate 22 and bottom plate 23, the dished 
members 31 and the plates 36 are inserted in the stack at the appropriate 
locations and the entire assembly is brazed together, so that post braze 
operations are not necessary. The fitting is appropriate for a heat 
exchanger formed of a conventional copper-brass material, for an aluminum 
or aluminum alloy heat exchanger where the aluminum parts are suitably 
brazed together, or for stainless steel or mild steel depending on the 
fluids passing through the heat exchanger.