US2306336A - Evaporative condenser - Google Patents

Description

Dec. 22, 1942. F. w. GILMAN EVAPORATIVE CONDENSER Filed June 28, 1940 INVENTOA FRANKLIN vv. GIL MAN y W ,L/

Patented Dec. 22, 1942 EVAPOBATIVE CONDENSER.

Franklin W. Gilman, Philadelphia, Pa., assignor to C. F. Moores 00., linc., Philadelphia, corporation of Delaware Application June 28, 1940, Serial No. 342,867

1 Claim.

This invention relates to an improvement in evaporative condensers or coolers, and particularly in evaporative condensers for use in a refrigeration system.

As is well known, mechanical refrigeration systems using a vapor readily liquefiable under pressure, as, for example, sulfur dioxide, ammonia, etc., comprise an evaporator, a compressor, and a condenser. In small installations the condenser may be air cooled, but in refrigerating systems of any substantial capacity, the condenser is water cooled.

Since in many installations the cost of cooling water is a major factor in the operating cost of the refrigerating system, it is desirable to use a type of condenser which will consume a minimum amount of water, and it has accordingly been proposed to use for this purpose evaporative condensers, i. e., a condenser in which the outer surface of the condenser tubes is kept constantly wet by a film of water, over which a current of air may be passed to accelerate evaporation.

It is a purpose of this invention to provide a simp.e, compact and eficient evaporative condenser, particularly adapted for use in refrigeration systems. The manner in which this and other purposes of this invention are attained will be apparent from the following description of a preferred embodiment of this invention, read in connection with the accompanying drawing, in which:

Figure l is a vertical section through a preferred type of condenser in accordance with this invention; and

Figure 2 is a section on the line 2-2, in Fig. l.

A sheet metal tank I forms the base of the apparatus and serves as a support for the other elements thereof. This tank is, in use, kept filled with water to a predetermined level by means of a float controlled valve 25 in the water supply line 25. A metal cover plate 3 forms the top of tank I, and is welded or otherwise secured thereto. A casing 2 is secured to the cover plate 3, which is cut away within the casing 2, as shown in Fig. 1. The casing 2 is, in plan section, in the form of a scroll, and terminates in an upwardly opening elbow 24, which serves as an air outlet from the apparatus. The top 2a of casing 2 is provided with a central aperture 22). An electric motor 6 is supported from plate 212 centrally above the aperture 2b on brackets 1.

Within the casing 2 the condenser tubing l1, through which the medium to be cooled or condensed passes, is placed, preferably in one or cient turns to fill casing 2 from top to bottom. Two coils are shown in the drawing, arranged in parallel with an inlet header 23 and an outlet header 24. However, any desired number of coils may be used, and the coils may be in parallel or comprise a single continuous tube. Preferably where several coils are used, they will be wound alternately in opposite directions. While it is not necessary for satisfactory operation, the tubing I1 will preferably be provided with fins I8 so as to increase the effective surface thereof.

The tubing lI may conveniently be secured, as by soldering, to the plate 2a and supported therefrom. A plate 5 having an aperture 511 concentric with aperture 217 is secured to plate 3' and closes the bottom of casing 2. Baffles l9 and Na close the space between the coils of tubing [1 and the top 2a and bottom 5, respectively, of casing 2.

A centrifugal, multivane type fan 9 is mounted in casing 2 within and closely adjacent the inner coil of tubing 11 on shaft 8, which is connected at its upper end to the drive shaft of motor 6 and is secured at its lower end in the bearing 20 mounted in bracket 22 suspended from plate 5. The bearing 20 has a rubber lining 2| and will operate under water without other lubrication. Preferably, as shown in Fig. 1, the fan 9 is of the double inlet type, with a hub plate H1 in the center, but a single inlet type may be used if desired. Air for the top half of the fan is supplied through ring 4 secured to the top 2a of casing 2 about the aperture 2b; and for the lower half, through aperture 21 in plate 3, beneath plate 3 above the water level and into the fan through the aperture 5a in plate 5.

Water for keeping the tubing l1 wet is supplied through a plurality of tubes, arranged to rotate with the fan wheel 9, the lower ends of which are placed beneath the water level in tank 1 adjacent the axis of rotation and the upper ends of which are located within the fan wheel 9 and are spaced from the aXis of rotation. The tubes are to be arranged about the fan wheel in groups of two or more, so that they will be in rotative balance. In the drawing, which illustrates the most simple arrangement, two substantially straight tubes II and I2, respectively, are placed diametrically opposite one another within the fan wheel at an angle to the axis thereof. The tubes, which should be of exactly the same length are placed with their upper endstouching, or nearly touching, the blades of the fan 9, while the lower endsextend below the water level in more close coils in the form of a helix of sufiitank I and are bent, as shown, to provide openings facing in the direction of rotation of the fan'and lying closely adjacent the axis thereof. The tubes l I and I2 are secured in place by being passed through apertures in the hub plate In and fastened, at their lower ends, as by soldering, to the shaft 8.

The tops of tubes II and I2 are closed, and tube ll, serving the upper portion of the structure, is provided with an aperture l3 in the outer side of the tube closely adjacent the top. Tube l2, serving the lower portion of the structure, is provided with a similar aperture M in its outer side at a level below the hub plate Ill, and also with a minute air hole IS in aside of the tube closely adjacent thetop. This insures that both tubes will n11 with water for their entire lengths, and will so be in rotative balance when filled. Similarly where v.morethan two tubes are used, each tube not provided with a water discharge aperture at its top will have an air hole at the top in addition to a water discharge aperture at alower level.

In operation, rotation of the fanwheel 9 by motor 6 draws a stream of air throughaperture 2'! and ring 4 into the casing Zand :forces it over the coils of tubing 11, whence it is discharged through outlet 24. At the same time tubes H and [2 are rotated and water is drawn by centrifugal force up through the tubes .from tank I, and discharged as a spray through the fan blades onto the coils of tubing H from apertures l3 and I4 respectively. The coils of tubing I! act as a bafiie, and due :to this action and the turbulence of the air stream leaving the fan 9, the spray leaving tubes H and 12 is quickly broken up and wets the entire surface of tubing l1. Substantially no spray passes through the coils of tubing, which as stated are closely spaced and preferably wound in opposite directions, to be carried out through the outlet 24. Excess water falling from the condenser tubing l1 re- In an evaporative condenser or cooler, spray- ,ingmeans. comprising a plurality of tubes arranged for rotation as a group about a vertical axis, the lower ends of said tubes being open, the upper ends of said tubes being closed except as otherwise specified herein and located at a greater radial distancefrom the axis of rotation of the group of tubesx than the lower ends thereof, the walls of said tubes being provided with apertures, certain of said tubes having said apertures at different vertical levels than others of said tubes, .and a relatively minute aperture for the escape of'occluded air located at the extreme upper end of eachsaid tube that is not provided with a wall aperture at substantially that. level, whereby all saidtubes may be filled for their entire length by liquid-drawn into them by centrifugal force on rotation of the group of tubes and so remain in rotative balance.

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