US2990700A - Airfoil evaporator with liquid distributor means - Google Patents

Description

July 4, 1961 B. E. wElBER'r, JR

AIRFOIL. EVAPORATOR WITH LIQUID DISTRIBUTOR MEANS Filed March l0, 1960 BY @www uw AGENT- United States Patent C) 2,990,700 AIRFOIL EVAPGRATOR LIQUID DISTRIBUTGR MEANS Bayard E. Weibert, Jr., P.0. Box 1636, Farmington, N. Mex. Filed Mar. 1960, Ser. No. 14,076 2 Claims. (Cl. 62-527) This invention relates to improvements in evaporators for air coolers and more particularly to an improved airfoil evaporator equipped with internal liquid refrigerant spray means.-

Air conditioning coils in common use today are designed to ydevelop maximum heat transfer through fine fin spacing with medium temperature ranges to provide a wide range of humidity control. However, as is evident in the art of automotive air conditioning, a considerably higher cooling capacity can be developed within tolerable limits of humidity control by using substantially lower coil temperatures. The fine humidity control assumed necessary in most air conditioning applications can be dispensed Iwith in certain cooling applications in addition to automotive air conditioning, for example, supermarkets and other shopping centers. As for the necessity of filtering the cooled air, while it does benefit to do so, there are many examples where filtering the air is not of suficient benefit to warrant the use of filters. However, the ne fin coil must have a filter when used as a dehumidifying means, otherwise the fine air passages will soon become clogged by wetted dust and lint passing through.

An important object of the present invention is to provide an evaporator incorporating rows of airfoil shaped heat exchangers that are relatively widely spaced apart to prevent clogging by dust and lint passing therebetween.

Another object of the invention is the provision of an evaporator with rows of smooth normally vertically disposed airfoil shaped heat exchangers characterized by high condensate liow which washes impinged matter down while allowing some particles to pass through and not require regular cleaning.

A further object is to provide an evaporator comprising rows of airfoil shaped heat exchangers suitable for operation Iat relatively low temperatures whereby a wide temperature difference between the exchanger surface and the passing air stream develops high cooling capacity.

Other objects and advantages of the invention will become apparent during the course of the following detailed description taken in connection with the accompanying drawing forming a part of this specification and in which drawing? IFIG. l is a fragmentary view of the airfoil evaporator partly in top plan and partly in horizontal section.

FIG. 2 is -a vertical cross sectional view of the evaporator taken substantially on the line 2-2 of FIG. 1 and diagrammatically showing the evaporator connected in a refrigeration circuit.

VIn the drawing which, for the purpose of illustration, shows only a preferred embodiment of the invention and wherein similar reference characters denote corresponding parts throughout the views, the numeral 10 designates a refrigeration circuit including a motor compressor 11 having a discharge pipe 12 for conducting hot gas to a condenser-receiver 13 provided with an outlet pipe 14 for conducting liquid refrigerant through an expansion valve 15 to a header I16.

Referring now to the evaporator 17, this unit comprises first and second parallel rows 18, 19 of spaced apart airfoil shaped heat exchangers having a staggered arrangement such that the heat exchangers 20 of either row 18, 119 are disposed opposite spaces 21 between heat exchangers 20 of the other rows 18, 19. Upright bafes 22,

ice

2-3 at opposite ends of different rows 18, 1-9 continue the staggered arrangement and maintain even spacing.

Each heat exchanger 20 comprises two spaced parallel'. sidewalls 24, 25 and rounded marginal edge walls 2.6, 2 7 forming a hollow body 28. These heat exchangersV 20 are disposed between and afiixed to upper and lower plates 29, 30 as by welding 31 so that each hollow body 2-8 is closed at both ends and the spacing of the rows 18, 19 and the individual heat exchangers 20 is made permanent. Disposed in central longitudinal relation in each heat exchanger body 28 is a liquid distributor tube 32 having an inlet end portion 33 that extends through the upper plate 29 and is fixed thereto as by welding 34. Each liquid distributor tube 32 is of a length substantially equal to the length of the heat exchangers 20 so that its lower end 35 terminates at the base plate 30. Each tube 32 is provided with longitudinally and circumferentially spaced perforations 36 and the upper ends 33 of the tubes 32 are connected by individual pipes 3-7 to the header 16 so that liquid refrigerant will be sprayed evenly over the inside surfaces of the heat exchanger bodies 28 during operation of the refrigerator system 10.

Located in the base plate 30 at the lower ends of the heat exchanger bodies '28 are ports 38 connected by outlet pipes 39 to a suction header tube 40 that returns the refrigerant to the motor compressor 11. This evaporator 17 lwith means for circulating air 41 through the branched passageways formed by the spaces 21 between the heat exchanger bodies 2.8 in the two parallel rows 18, 19 is wel-l suited for use as a suspended unit cooler capable of being spotted with other units of the same type in large areas such as in supermarkets and other shopping centers and without needing expensive duct work.

In the operation of the evaporator 17, the liquid refrigerant travels down the perforated distributor tubes 32 each in a different one of the heat exchanger bodies 28 and is sprayed through the spaced perforations 36 onto the inside surfaces of the bodies 28 and leaves through the outlet pipes 39 in the base plate 30. By using smooth airfoil shaped heat exchangers 20 at low temperature for cooling, the use of filters is avoided and high cooling capacity is developed through the use of the inserted perforated tubes 32 and the provision of the relatively large area of the evaporator surfaces.

This construction eliminates the accumulation of liquid at the bottom of the hollow heat exchanger bodies 28 and resultant uneven temperatures of the heat exchanger surfaces.

Various changes may be made in the form of invention herein shown and described without departing from the spirit of the invention and the scope of the following claims..

I claim:

1. An evaporator comprising a plurality of elongated normally vertical hollow bodies of airfoil shape in cross section, lower and upper spaced common end walls between which said elongated hollow bodies extend and are fixed in spaced parallel relation, said lower end wall being provided with uid outlets each for a different one of said hollow bodies, a plurality of liquid distributor tubes each having an inlet end portion for receiving liquid refrigerant, means fixing said tubes in central longitudinal relation each in a different one of said elongated hollow bodies with their inlet end portions extending `through said upper end wall, said tubes having perforations spaced to spray liquid refrigerant onto the inside surfaces of said hollow bodies, and headers one connected to said outlets and another to said inlet end portions.

2. An evaporator comprising adjacent parallel rows of elongated normally vertical hollow bodies of airfoil shape in cross section, lower and upper spaced common end walls between which said elongated hollow bodies extend and are fixed in spaced parallel relation with the bodies of each row in alignment with the spaces of the adjacent row, said lower end wall being provided with tluid outlets each for a different one of said hollow bodies, a plurality of liquid distributor tubes each having an inlet end portion for receiving liquid refrigerant, means fixing said tubes in central longitudinal relation each in a different one of said elongated hollow bodies with their inlet end portions extending through said upper end wall, said tubes having perforations spaced to spray liquid refrigerant 10 2,508,625

onto the inside surfaces of said hollow bodies, and headers .one connected to said outlets and another to said inlet end portions.

References Cited in the le of this patent UNITED STATES PATENTS 1,887,093 Harnett et al Nov. 8, 1932 1,952,896 Rudortf Mar. 27, 1934 2,327,140 Speirs Aug. 17, 1943 Smith May 23, 19501l

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