US2532452A - Externally adjustable tubular fluid flow restrictor for refrigeration systems - Google Patents

Description

Dec. 5, 1950 A F HO 2,532,452

ESEL EXTERNALLY ADJUSTABLE TUBULAR FLUID FLOW RESTRICTOR FOR REFRIGERATION SYSTEMS Filed June 14, 1945 IN V EN TOR.

Patented Dec. 5, 1950 UNITED STATES PATENT m 2 1 EXTERNALLY ADJUSTABLE TUBULAR FLUID FLOW RESTRICTOR FOR 1113- FRIGERATION SYSTEMS Anthony F. Hoesel, Chicago, 111., assignor, by mesne assignments, to Albert Wittlin, Chicago,

At present, most domestic mechanical refrigerators employ either an automatic expansion valve or a capillary tube to maintain the necessary pressure differentials between the high pressure and low pressure sides of the system.

For my purpose, we can disregard the operation with the automatic expansion valve. One of the difficulties, of using a capillary tube for the purpose, is that it practically has to be a laboratory determined method and cannot be employed by an ordinary service man, in the field, except with a factory replacement for the particular unit.

Many systems would have the atuomatic expansion valve replaced with a capillary tube, if the service man would know exactly the correct capillary tube bore size and correct length of capillary tube for the particular job.

Since the presently employed capillary tubes depend upon a given length of uniform bore to produce the necessary flow restriction for the maintenance of the necessary pressure differentials, between the condenser and the evaporator. there is no means for adjustment and the correct capillary tube, as factory determined, must be used on any particular job.

Strictly speaking, my invention does not contemplate a capillary tube, although it employs tubing of relatively small size in the practice thereof. Taking a system, which would ordinarily have a standard capillary tube of say, .040" bore and, say, 36" length, I would have a tube of, say, .060" bore and only about -6" length. In order to get an equivalent restrictor effect, I propose a rather novel means of making the bore adjustable, at some certain point or points, without the use of valves or other expensive means generally equipped with stuffing boxes or equivalents.

An object, of the present invention is to provide a novel means of adjusting a tube bore in order to control a fiuid flow rate therethrough.

Another object, of the present invention, is to provide an inexpensive adjustable fiow restrictor for use with refrigeration systems.

Further objects, of the present invention, will be disclosed within the following specification and claims.

In the drawings:

Fig. 1 is a view of a refrigerating system employing the invention.

Application June 14, 1945, Serial No. 599,489 zolaims. (01. 138-45) Fig. 2 is a cross-sectional view of the flow restrictor; of Fig. 1. Y

Referring to the drawings: 1

In Fig. 1, a compartment 1 is cooled by means of a cooling coil 8 from which-the compressor 9, driven by means not shown, evacuates refrigerant vapor by means of the suction conduit 10 connecting .therebetween. The compressor 9 compresses the vapor into the discharge conduit llleading to a condenser I2 wherein the compressed vapor surrenders its heat and becomes liquefied prior to its entry into the liquid conduit I3 leading to the pressure restrictor I4, which discharges to the cooling coil 8. q a

In Fig. -2, the pressure restrictor l4 comprises two flared tube end fittings l6 and I1 between which, and in the bores l8 andl9, is placed a tube 20 of copper, in the present instance, and having a bore 2|, which is generally, initially, of uniform diameter. The tube 20 is soldered to the end fittings I6 and I1, as indicated, at 22 and 23 respectively.

The tube bore adjusting means comprises a ferrule 21 having a diametral taper toward each end thereof and an initial bore which is a slip fit over the tube 20.

The compression member 28 has a bore 29, which is-a slip fit over the tube 20, and a taper bore 30 somewhat similar to the diametral taper of the ferrule '21 engaging therewith.

The compression member has a bore 34, which is a slip fit over the tube 20, and a taper bore somewhat similar to the diametral taper of the ferrule 21 engaging therewith.

The compression member 21; has a threaded bore 31 engaging the male thread 38 of the compression member 33. Screwingjpp the compres sion members 28 and 33 resultfsffz in the respective tapers 30 and 35 approaching each other and compressing the ferrule 21 therebetween. This reduces the initial bore, of the ferrule 21, and squeezes the outside diameter, of the tube 20, at that point, whereby I now have a reduced boretn which is of diametral form.

Whenever a tube is so compressed, the tube wall thickness, at the point of compression, is

materially increased; therefore, the original tube strength is only slightly disturbed.

Since the reduced bore is of diametral form, same as originally except reduced in size, it has the virtue of being able to pass foreign matter of many times the size which would clog up a needle valve, associated with a valve seat having a bore equivalent to the initial bore of the tube 20, ads justed to equivalent fluid flows.

Since the bore reduction is comparatively gradual, during the screwing up of the compression members, the proper size thereof is easily attained.

Instead of soldering the tube 20, as at 23, I might combine the male. thread 38 and the taper 35 with theflared end fitting H, resulting in" decreased expense.

In effect, What I have done is to provide an ad,-

justment to regulate fluid flow through a. tube.

without the use of valves, etc.

While the invention is definitely adaptable to refrigeration systems, it has a much Wider field of utility and I do not wish to'beconfined thereto;

While the drawings show=and the specification explains a particular embodiment of the invention, it is to be understood that variousmodifiea-.

two inter-engaged threaded compression members'mounted on the tube at opposite ends of the ferrule and arranged to engage the same andcapable of compressing both the ferrule and the tube wall during wrench-up; so that the tube bore may bev contracted; for controlling the flow rate of the volatile refrigerant fluid through the assembly.

2. For interposition in the liquid circuit of a refrigeration system having an evaporator, a pressure restrictor comprising a tube of compressible metal having a potential refrigerant liquid flow rate in excess of the vaporizing capacity of the evaporator, andcompression means comprising a ferrule arranged on the tube between the ends thereof, said ferrule being oppositely tapered toward its ends, and two interengaged threaded compression members slidably mounted on the tube at opposite ends of the ferrule andhaving tapered portions arranged to engage the tapered portions of the ferrule and capable ofrelative adjustment to compress the ferrule radially to reduce the size of the opening in the ferrule and compress the tube inwardly and reduce the diameter of the bore and simultaneously increase the wall thickness of the reduced portion of the tube.

ANTHONY F. I-IOESEL.

REFERENCE S CITED The following references are ofrecord in. the file of this patent:

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