Heat exchanger with integral filter/drier cartridge

A heat exchanger or condenser for a refrigerant system having an inlet tubular heat exchange surface and an enlarged tubular outlet. A cartridge type filter/drier has a shell or canister containing desiccant secured to a header with an outlet. In one embodiment the header is welded in the condenser enlarged outlet; and, in another embodiment the header is sealed in the enlarged outlet by an o-ring and retained by deforming the outlet tube over the header.

BACKGROUND OF THE INVENTION 
The present invention relates to exothermic heat exchangers and 
particularly heat exchangers of the type employed for cooling of 
compressed refrigerant gas discharged from a compressor, which are often 
referred to as condensers due to the change of state of the refrigerant 
from a gas to a liquid during cooling. In providing condensers for 
refrigerant gasses and the associated conduits for connection to the other 
components of the refrigerant system, it has heretofore been the practice 
to incorporate a filter/drier in the system conduits on the discharge or 
downstream side of the condenser. 
In refrigerant systems employed for vehicle passenger compartment air 
conditioning systems, it has been common practice to mount a drier/filter 
on the vehicle body at a location generally adjacent the condenser such 
that the conduit connections from the drier/filter to the expander for the 
evaporator intake are maximized to continue the cooling function of the 
condenser. This arrangement permits any condensed refrigerant gas 
discharging from the condenser to be further cooled by the filter/drier 
and the conduits leading to and from the filter/drier thereby ensuring 
that only high pressure liquid refrigerant enters the expander. 
In vehicle air conditioning systems, the competitive nature of the 
marketplace dictates that the cost of the air conditioning refrigerant 
system be minimized. Accordingly it has been desired to reduce the number 
of conduit connections and fittings required for a vehicle air 
conditioning system and particularly those of the type employed in mass 
produced passenger automotive vehicles. It has thus been desired to 
provide a way or means of incorporating a filter/drier into an automotive 
air conditioning system with a minimum of conduit fittings and 
connections. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide an exothermic heat 
exchanger having an integral filter/drier incorporated in the construction 
thereof. 
It is a further object of the present invention to provide the condenser 
for circulating refrigerant and to incorporate a filter/drier in the 
construction of the condenser. 
It is a further object of the present invention to incorporate a 
filter/drier cartridge into the outlet of a refrigerant condenser. 
It is a further object of the present invention to provide a filter/drier 
cartridge which is assembleable into the outlet of a refrigerant condenser 
integrally during the manufacture of the condenser. 
The present invention provides an exothermic heat exchanger having a 
tubular conduit with an inlet and an enlarged outlet portion formed in the 
end of the conduit remote from the inlet with a preassembled filter/drier 
cartridge received in the enlarged outlet portion. The cartridge has a 
basket having the rim of the open end attached to a header with an outlet 
port formed therein. The basket contains desiccant material and is 
perforated in the end remote from the header such that upon assembly of 
the cartridge into the enlarged outlet portion of the condenser 
refrigerant flows into the perforated end of the basket and through the 
desiccant to the header outlet. In one embodiment the header is sealed in 
the condenser outlet by a resilient seal ring and the enlarged outlet of 
the condenser is deformed over the header to retain it in position. In 
another embodiment the header is peripherally welded about the enlarged 
end of the condenser after assembly of the cartridge therein.

DETAILED DESCRIPTION 
Referring to FIGS. 1 and 2, the heat exchanger assembly is indicated 
generally at 10 and has an inlet to adapt it for external connection 
thereto denoted by reference numeral 12 for receiving a flow of 
pressurized fluid such as refrigerant therein. In the presently preferred 
practice, the inlet 12 is connected to one end of a manifold tube 14 which 
has at the remote end thereof an enlarged portion denoted by reference 
numeral 16. A second manifold tube 16 is disposed in spaced generally 
parallel arrangement with the manifold 14; and, the manifolds 14 and 16 
are interconnected as will hereinafter be described by a plurality of 
cross tubes. 
It will be understood that the heat exchanger construction illustrated in 
the drawings is arranged in the preferred manner for an application in an 
automotive air conditioning system; however, other arrangements may be 
employed as, for example, a continuous tube having a serpentine or 
sinusoidal configuration between the inlet 12 and outlet 16. 
Referring to FIGS. 1 and 2, the first manifold 14 has a plug or partition 
18 disposed therein at a desired distance from the inlet 12 such that a 
common end of a plurality of cross tubes denoted by reference numerals 20, 
22, 24 are in communication with a chamber 19 and the inlet 12; and, the 
opposite end of the tubes 20, 22, 24 are connected to the upper end of 
manifold 16. A second plurality of manifold tubes denoted by reference 
numerals 26, 28, 30 have one common end of each connected to the manifold 
16 with the opposite end of each tube 26, 28, 30 connected to chamber 39 
in manifold 14 on the side of plug 18 opposite the tubes 20, 22, 24. A 
second partition or plug 32 is provided in the manifold 16 to isolate to 
form a common chamber 33 in the manifold communicating with the tubes 
20-30. A third plug or partition denoted by reference numeral 38 is 
provided in manifold 14 to form the chamber 39. 
it will be understood that flow entering inlet 12 flows into chamber 19 and 
through tubes 20, 22, 24 into the chamber 33 in manifold 16 and returns to 
chamber 39 in manifold 14 through tubes 26, 28, 30. An additional 
plurality of tubes denoted by reference numerals 34, 36 each have a common 
end thereof attached to chamber 39 in manifold 14 with the opposite end of 
each attached to manifold 16 to communicate with the chamber 37 formed 
below plug 32. 
Thus flow returning from tubes 26, 28, 30 in chamber 39 flows through tubes 
34, 36 into the chamber 37 in manifold 16. 
A plurality of tubes denoted by reference numerals 40, 42 has one common 
end of each connected to manifold 14 below plug 38 to communicate with the 
outlet chamber 44, with the opposite end of the tubes 40, 42 connected to 
manifold 16 to communicate with the chamber 37. Thus flow entering chamber 
37 from tubes 34, 36 returns to manifold 14 in chamber 44 via tubes 40, 42 
and from chamber 44 flows to the outlet 16. 
Referring to FIG. 3, the enlarged end portion 16 of the manifold 14 has 
received therein a filter/drier cartridge indicated generally at 46 which 
is formed of a header 48 having an outlet passage 50 formed therein with a 
basket or shell 52 having the rim of the open end thereof attached to the 
header 50. In the presently preferred practice the header 50 has a reduced 
diameter portion 54 which is undercut at 56 such that the end of the 
basket 52 is deformed such as by crimping thereover and is thus retained 
thereon. The end of the basket 52 remote from header 48 is perforated to 
form apertures 57 preferably by punching out tabs as denoted by reference 
numeral 58. 
The basket 52 is filled with a suitable desiccant material indicated by 
reference numeral 60 which is preferably of a granular form. 
A perforated metal cup 62 having a plurality of apertures 61 is pressed 
into the end of the shell 52 and forms a plenum chamber 63 between the 
desiccant material and header outlet. In the presently preferred practice 
a layer of suitable filter material such as for example fibrous glass 
material is disposed adjacent the inner surface of the perforated end of 
the cup 52 and also adjacent the perforations in the cup 62 in the 
interior of the basket 52. 
In the embodiment of FIG. 3, the header is peripherally welded to the 
enlarged diameter portion 16 of the manifold 14 as indicated by reference 
numeral 64 to seal and retain the header to the outlet portion 16 of 
manifold tube 14. 
Referring to FIG. 4, an alternate embodiment of the invention is 
illustrated as having a tubular heat exchanger manifold 114 having an 
enlarged outlet end 116 with a filter/drier cartridge denoted generally at 
146 received therein. The cartridge 146 has a basket or shell 152 with 
perforations 157 in one end and attached by the deforming the rim thereof 
156 over an undercut 154 provided in a header 148 having outlet port 150. 
The basket is filled with desiccant material 160; and, the header 148 has 
a resilient seal ring received in an annular groove 172. In the embodiment 
of FIG. 4 the end of the enlarged tubular portion 116 of manifold 114 is 
deformed over a chamfered surface 174 provided on the header to retain the 
header and cartridge in the outlet formed by the enlarged portion 116. 
The present invention thus provides a novel heat exchanger particularly 
suitable for the refrigerant condenser employed in automotive air 
conditioning applications and has a cartridge type filter/drier assembled 
integrally into the construction of the heat exchanger. 
Although the invention has hereinabove been described with respect to the 
illustrated embodiments, it will be understood that the invention is 
capable of modification and variation and is limited only by the following 
claims.