US2537497A - Fluid feed device - Google Patents

Description

Jan, 9, 1951 E, A WEAVER 2,537,497

FLUID FEED DEVICE Filed Dec. '7, 1946 "Patented Jan. 9, 1951 UNITED STATES Mmmg OFFICE FLUID FEED DEVICE Eastman A. Weaver, Winchester, Mass., assgnor, by mesnc assignments, to Stator Company, a corporation of Massachusetts Application December 7, 1946, Serial No. 714,799

6 Claims.

This invention relates to a self-regulating, continuous, heat-operated, fluid-feed device suitable for a wide variety of applications and, as illustrative of its utility, is herein shown as applied. to an ejector-refrigeration,apparatus of the type illustrated in United States Patent 2,174,301, granted September 26, 1939.

The principal object of the invention is to replace many of the complex, expensive, shortlived feed pumps now used by a single relatively inexpensive device subject to little wear and requiring no mechanical power supply. Other objects are to provide a hermetically sealedautomatic boiler feed suitable for apparatus, such as refrigeration systems, using a permanent selfcontained charge of fluid which must not leak away or be contaminated by atmospheric leakage; and to provide a boiler feed adapted to replace hand-controlled boiler feeds, such as injectors, by a self-regulating apparatus which will function only when needed. Further objects will be apparent from a consideration of the following description. n

It is known that boiling gas-free liquids pass into the vapor phase not continuously,y as in evaporation, but in a series of fbumps caused by the fact that minute bubbles cannot form until substantial superheating of the liquid above its boiling point has occurred, at which time a sizable bubble appears, sometimes with such violence as to break a glass container. lf the liquid be confined within an elongated chamber or tube in which a series of co-directed check valves are interspaced to define compartments at least partially filled with the boiling liquid, the bumping or sudden formation of each bubble tends to expel part of the fluid from its compartment and, due to the action of the check valves, the expulsion of the uid is limited to one direction. By continuing the bumping action by applying the required degree of heat to the compartment, the intermittent oscillating pressure thus produced can be rectified to produce a flow of fluid even against a large pressure difference, if the number of units is adequate. The principle thus involved is to be distinguished from the action of a percolator which involves an air-lift principle working against little or no appreciable pressure head, and which does not depend uponintermitt'ent generation of vapor from a superheated liquid.

The invention may advantageously be applied to absorption-refrigeration apparatus to feed an absorbent-refrigerant solution, or to ejector-refrigeration apparatus to feed ak propellant fluid autmatically. Mathe beilerrgainsi a. Substanf..

. 2 -f tial pressure, thereby permitting operation with'- out mechanically-actuated valves or pumps which require power and usually involve more or less leakage to the atmosphere. This may be accomplished by including as a part yof a boiler or generator a heated conduit comprising a series of codirected check valves constructed and arranged so as to dene a plurality of spaced compartments each containing the boiling uid. The conduit may communicate with the boiler proper or a manifold, except in certain cases where it may prove advantageous to make the entire boiler of these' valve-spaced conduits arranged in series and/or in parallel, as for example in absorption refrigeration, where separation of fluids by distillation is involved and maintaining a pressure difference is essential. i

Since such a device is actuated by individual bubbles, it works lbest with the boiler compartiments'quite small. Thus, its unique advantages are most apparent for small apparatus, although it is to be understood that the conduits may be combined in parallel to furnish an adequatellow required for large installations, as well as in series to furnish relatively high pressures.

In its simplified form, the device comprises a series of valve seats which are pressed, soldered,

k brazed, or otherwise secured at intervals within f developed within the compartments may be found` necessary, depending upon the particular condi-P tions. The vertical arrangement for upward flow s has the" additional advantage of advancing Athe vapor preferentially as compared with the liquid, this being desirable, as the bumping is less ef" fective when cushioned by the presence of much vapor in the compartment, and hence the vapor should be passed out of the units or compart-' ments as rapidly as possible. However, other considerations may lead to the placing of these conduits horizontally or even for down flow in special'fcase's'.,

A Referring to the accompanying drawings which illustrate the application of my device to a typical absorption-refrigeration apparatus:

Fig. l is a diagrammatic view of the system embodying the present invention;

Fig. 2 is an enlarged vertical section through the boiler-feeding apparatus; and

Figs. 3 and 4 are sections on the lines 3-3 and 4 4, respectively', of Fig. 2.

The system herein shown comprises a nre box or heating chamber C equipped with suitable heating means, such as a gas burner B, and with-` in the chamber is a small boiler or vaporizor i which normally contains a body of suitable propellant, such as mercury. The lower end or botl tom wall of the boiler is connected with a feeding device 2, constructed in accordance with the present invention, and the upper end or topI of the boiler is connected with a riser 3 for conducting mercury vapor to an aspirator nozzle from which the mercury vapor issues as a high velocity jet into a mixing chamber 5.

` The mixing chamber 5 is connected by 'a vapor fduct 6 to a cooler i which normally contains a The 'drain pipe i2 connected to the lower end of the funnel, while the refrigerant vapor flows vpwardi" lythrough a vapor duct iltto the refrigerant condenser l5. The condensed refrigerant is received from the condenser i5 by a return pipe l5 having a trap Il at its lowerV end which contains a smaii body of mercury. Refrigerant liquid piling 'up in the pipe i6. develops suilicient head so that lsome of the refrigerant may pass by the mercury into` the trap and ow through a pipe i8 back to the cooler T.

A trapY i9? has one leg connected 'to the bottom of the cooler 'l and its other leg is connected with a downwardly inclined pipe 2d. The trap contains -a bod-'yof mercuryv and the construe* tion and arrangement of parts are such that when 'stray mercury is received from the cooler, the mercury may overflow the trap It intor the pipe 201. The lower end of the drain i2 also. communi- Cates through a trap 2i with the lower end of the inclined pipe 2i! which is connected toA a return line 22. The. pipe 22 is; connected to a check valvev 2d which in turn is connected to Ia return pipe 2'5 communicating with the lower end of the feeding device 2. `The check velvet 2A, as shown in'FigsQ' and 4, comprises a cylindrical member having a truste-conical, shaped interior abovev which is a square or non-circular; shaped dist.Y 26 having aflat upper surface adapted to seat against the flat under-surface of the head or: closure plate 28, in response to back pressure or fluid ow, thereby to vpermit flow of uid only toward the feeding device 2, as indicated by the arrows in Fig. 2. v

.fIThe feeding deviceor bumper feed 2A comprises an elongate vertically disposfd cylindrical ube having, a closed lower end wall 3| to whch the. return pipe 25' is connected. Within the tube 311 is disposed a plurality of transversely extending partitions providing aligned check valves, caen consisting of an inverted dishfshapedcircular valve member 32 having a 'central opening 33 in its top wall and a side wall which is tapered or beveled as indicated at 34 adjacent to its junction with the top wall so as to dene a chamber having a frusto-conical upper end, as shown in Figs. 2 and 3. A gravity-operated flat valve disk 35 of square or non-circular shape seats squarely on the upper face of each valve member 32 so as normally to close its associatedv valve opening 33.` The valve members 32 thus denne a series of spaced compartments, each having codirected valves operative to permit uid to pass upwardly in response to a pressure surge or wave, but opposing downward movement of the fluid. It will be observed that due to the non-circular shape of the valve disks 35 and the frusto-conical shape of the valve members 32, each valve disk is inelectve to close the valve opening just above it when forced from its seat. Hence, a surge or pressure wave created within any compartment is effective to seat the valve disk; within that compartaient rmliy on its seat so as to prevent downward flow of and at the same time raise or unseat the valve dishl of the compartment next above.

The upper end of' the feeding device 2` may be welded or otherwise suitably secured to the boiler I, and both are disposed within the re box- C so that the feeding device is positioned to receive adequate heat from the burner B to effect the bumping action, it being understood that the burner B may be automatically controlled to supply fuel in accordance with the requirements of the system.

A summary of the operation of the systemv is as follows VAssuming that the boiler l, trap Zi and return 2-2 contain the proper level' of mercury, as indi- I' plied to the boiler lV and feeding device 2 cated in Fig. 1, and that the cooler l contains the proper amount of liquid refrigerant, heat apenerates mercury vapor which passes through the tube 3 int-o the aspirator nozzle fr from which the mercury vapor issues as a high velocity jet into the mixingv chamber 5, thereby' drawing refrigerant vapor through the duc-t S, which is entrainedwith the stream ofmercuryvapor. lCondensation of the mercury vapor takes place within the funnel 8', and the mercury condensate passes into the drain i2', through trap 2i into the return line 22, while the compressed refrigerating vapor passes through the condenser i5` The mercury condensate flows through the check: valve 24,4 as above explained, into the feeding device 2. Since the mercury within the vapor-generating compartments of the feeding device E is subjected to the main body of the flame issuing from the burner B, it is superheated suilciently to eect the desired bumping action, and hence feeds the return fluid in the form of mercury vapor and entrained liquid mercury back into the boiler i. When all the returned mercury in return-line 22 has been fed, the rate of pumping will of course diminish for lack of supply, and when the mercury contained in the feeding-device has been reduced sunlciently, feeding will cease until more returnf mercury accumulates. The valves, however, com tinue to maintain the pressure-difference. Thus the feeding-device is self-regulatory, functioning only as there is liquid to be fed.

pose of illustration and' that variousy changes and modifications may -be made without depart;

ing from the spirit and scope of the invention as set forth in the appended claims.

I claim:

1. A heat-operated Huid-feeding device which comprises the combination of a heat generator and an enclosed chamber having an inlet and an outlet, and a plurality of co-directed checkvalves defining a plurality of vapor-generating zones between an inlet and an outlet in heat transfer relation to said generator, said checkvalves being effective to permit unidirectional fluid-flow from inlet to outlet and to prevent counter-flow.

2. A heat-operated fluid-feeding device which comprises the combination of a heat generator and an elongate member having an outlet at one end and an inlet at its opposite end, and a plurality of co-directed check valves within said member interspaced between said inlet and outlet and deiining a plurality of vapor-generating zones in heat transfer relation to said generator, said check valves being effective to permit fluid ow only in a direction toward said outlet.

3. A heat-operated fluid-feeding device which comprises the combination of a heat generator and an elongate passage having an inlet at one end and an outlet at its other end, a plurality of spaced partitions extending across said passage and defining a plurality of vapor-generating compartments in heat transfer relation to said generator, each partition having a valve opening and a valve seat about said opening, and a normally closed valve member associated with each valve opening and arranged so as to permit uid ow only in a direction toward said outlet.

4. A heat-operated fluid-feeding device which comprises the combination of a heat generator and an elongate vertically disposed channel having an inlet at its lower end and an outlet at its upper end, a plurality of vertically spaced partitions extending across the interior of said channel and defining a plurality of vapor-generating compartments in heat transfer relation to said generator, each partition having a valve opening and a valve seat extending about said opening, and a gravity operated valve disk disposed on each seat for normally closing the valve opening, the valve disks being arranged so as 6 to permit fluid flow only in a direction toward said outlet.

5. A heat-operated uid-feeding device which comprises the combination of a heat generator and an elongate cylindrical tube having an inlet at one end and an outlet at its opposite end, a plurality of axially spaced partitions extending across said tube and defining a plurality of vapor-generating compartments in heat transfer relation to said generator, each partition having a valve opening and a valve seat extending about said opening, the wall of each partition facing the inlet end of said tube being of frustoconical shape, and a normally closed valve disk of non-circular shape disposed against said seat, the valve disk being operative to permit fluid flow only in a direction toward said outlet.

6. A heat-operated fluid-feeding device which comprises the combination of a heat generator and an elongate vertically disposed cylindrical tube having an inlet at its lower end and an outlet at its upper end, a plurality of vertically spaced partitions extending across said tube and defining a plurality of vapor-generating compartments in heat transfer relation to said generator, each partition having a centrally disposed valve opening, the upper face of each partition defining a flat valve seat extending about said opening and the undersurface of each partition being of frusto-conical shape, and a grav-y ity operated non-circular valve disk disposed on each seat, the valve disks being collectively operative to permit flow of fluid only in a direction toward said outlet.

EASTMAN A. WEAVER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,624,014 Schneider Apr. 12,V 1927 2,174,301 Whitney Sept. 26, 1939 FOREIGN PATENTS Number Country Date 850,942 France Sept. 25, 1937

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