US894285A - Refrigerating apparatus. - Google Patents

Description

No. 894,285. I PATENTEA) JULY 28,1908.

' H. RASSBACH.

REFRIGERATING APPARATUS.

APPLICATION FILED SEPT.14, 1903.

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UNITED STATES PATENT OFFICE.

HERMANN RASSBACH, OF MILWAUKEE, WISCONSIN. ASSIGN 011 TO THE VILTER MANUFAC- TUBING COMPANY, OF MILWAUKEE, WISCOhSl'N, A CORPORATION OF WISCONSIN.

REFRIGERATING. APPARATUS.

Specification of Letters Patent.

Patented July 28, 1908.

Application filed September 14, 1903. Serial No. 173,031.

To a] Z whom it may concern: v Be it known that I, ,HERMANN RASSBACH, a citizen of the United States, residing at Milwaukee, in the county ofgMilwaukee and State of Wisconsin, have invented certain new and useful Improvements in Refrigerating Apparatus, of which the following is a specification, reference being had to the accompanying drawing, forming a part thereof. This invention relates to that class of refrigerating apparatus in which a volatile liquid is employed as the refrigerant to, absorb or abstract the heat of surrounding or adjacent bodies or substances, and the gas or .vapor resulting from the evaporation of the liquid is reliquefied, so that the same refrlgerant is used over and over again in a con,

tinuous cycle.

The main-objects of the invention are to automatically regulate the supply of a cooling agent to a plurality of coils or chambers or to the several parts of a refrigerating system according to the varying conditions and demands in such a system, and thus over- 5 come the difiiculties heretofore eX erienced in supplying to each of the severa parts of the system the requisite quantity-of cooling agent for the efiective and economical operation thereof; to avoid the return of liquefied 39 gas to the compressor or other condensing apparatus; to return to the refrigerating plates or coils or to the expansion chambers all of the cooling agent which is discharged therefrom in aliquid state, thereby utilizing 5 its full efficiency to avoid the care, trouble and uncertainty incident to the manual regulation of the supply of the cooling agent to the several parts of a refrigerating system; to utilize the liquefied refrigerant condensed 40 by the operation of throwing off and liberating the finished ice from the freezing plates for immediate and effective work in active freezing coils; and generally to simplify and improve the construction and operation of apparatus of this class.

The invention consists in certain novel features of construction and in the peculiar arrangement and combinations of parts hereinafter particularly described and summarized in the claims.

In the accompanying drawing like characters designate the same parts in both figures. Figure 1 is a diagram and sectional view of apparatus embodying the invention and designed for use in the manufacture of ice;

and Fig. 2 is a perspective view of a part of the apparatus shown in Fig. 1.

Referring to Fig. 1, showing refrigerating apparatus embodying myinvention, h designates a closed tank or reservoir, which may becalled an accumulator.

& designates one of a number of cooling coils or pipes, which for the purpose of more readily liberating the ice formed thereon, are covered on both sides by thin metal sheets j, held in close contact therewith by metal straps or bars 9'' which support the several sections or parts of each coil and are bolted thereto over the edges of said sheets, as shown in Figs. 1 and 2. These sheets on the opposite side of each coil are also connected and clamped to the coil by bolts at intervals between said supporting straps or bars. As they do not or need not form water tight chambers for the coils and are not required to support the coils, they may be and are preferably made comparatively thin and light. Any desired number of these coils covered as above stated are-arranged at suitable intervals and parallel with each other in a steel or metal tank k, for holding the water to be frozen. The ends of the coils are connected with horizontal headers or manifolds Z and m, their connections therewith being provided with stop cocks n and 0, for the sole purpose, as hereinafter explained, of shutting ofi any of said coils from said headers. header Zis located below and connected with the lower part of the accumulator h in such relation thereto and to the coils that when the cooks n and 0 are opened, liquid will flow from the accumulator by gravity alone into and simultaneously fill or partially fill all the coils to the same level. The header m is located above the header Z. and is connected with the accumulator at any convenient and suitable point above the bottom thereof.

The l The top or upper part of the accornulator h v accumulator orreturn conduit for the gas'areconnected in this pipe, which is provided at a convenient point between the coil a and the suitable material, and inclosing an air space along the sides and bottom of the tank. This s ace is divided midway between and paralle with the coils by the timbers which support the tank or otherwise, into ducts or passages :10, and these ducts communicate through ports or openings controlled by valves y, with an air duct 2 extending along one side of the tank and connected with a source of hot or warm air.

Each of the coils t is connected at its upper outlet end with a header 2, which is in turn connectedby a pipe 3 with the discharge pipe 8 between the compressor q and the condenser t. The connection of each coil with the header 2 is provided with a valve 4.

The several spacesbetween the sheet metal covered coils in the tank are connected with each other at the bottom by a header 5 and branch pipes 6, provided with valves 7, by means of which connections a uniform water level: is maintained in the several parts of the tan To determine and maintain a certain depth of water in the tank 7c it is provided with an overflow pipe 8. The tank is supplied with water from a header 9, provided at convenient intervals with valves and hose connections 10. q

Branch pi es 11 provided with valves '12, lead into the lower parts of the sections of the freezing tank from one or more compressed air supply mains 13.

My improved apparatus, constructed and arranged for making ice as hereinbefore described, operates as follows: It is well known to those familiar with the art to which my invention pertains, that liquid anhydrous ammonia boils, or is converted into a gaseous state at a temperature of about t Fahrenheit below zero, and under a pressure of about fifteen pounds per square inch above that of the atmosphere. It is also well understood that for converting a liquid into a gas or vapor, heat is required. If therefore, the accumulator h is partially filled, as shown in Fig. 1, with liquid anhydrous ammonia, at the temperature and under the pressure above mentioned, this liquid will flow by gravity through the header Z into the coils i, filling them all to the level of the liquid contained in the accumulator. The liquid ammoma coming in contact with the metal pipe QOIlS which have a temperature corresponding with that of the Water in the freezing tank, this temperaturebeing much higher thanthe boiling point of the ammonia, will boil or be converted into vapor or gas, ab-

sorbing the heat for its evaporation from the coils and surrounding water. The ammonia steam or gas thus produced entraining with it more or less of the liquid ammonia, will escape from the coils through the manifold m, into the accumulator, where the liquid will be precipitated, while the gas separating vfrom the li uid passes by the pipe 1), through the forecoo er 1, to the com ressor g, to be recompressed and returned t rough the condenser t and cooling'coil a into the accumulator. The liquid refrigerant thus returned from the coils and precipitated in the accumulator under the same pressure and hence at the same temperature as the gas escaping therefrom, being available for effective work, flows again into the active freezing coils.

The heat of the water in tank is transferred to the liquid ammonia in the coils i, converts the same into steam or gas. It follows that the temperature of the water Will thus be reduced until it reaches the freezing oint and congeals'on the plates the ice ecoming gradually thicker while the process of evaporation and circulation of the refrigerant in the coils is continued. This process of evaporation is made continuous by the supply through the pipe 8 to the accumulator from the compressor of an amount of liquid ammonia equal to that escaping from the accumulator in the form of gas to' the compressor. The liquid ammonia returning from the compressor through the condenser to. the accumulator, is of a much higher temperature and under much greater pressure than are maintained in the evaporating and cooling coils of the apparatus. If the liquid refrigerant were liberated from the high pressure under which it is delivered from the condenser, its sensible heat at the, high tem erature corresponding to that pressure Wou d be consumed at once in converting a part of such liquid into gas, and that part would be lost for effective refrigeration in the freezing coils. To prevent this loss it is necessary to deprive the liquid refrigerant of its excess of sensible heat and thus destroy its @718 viva, before it is admitted into the accumulator and before itis relieved from its high pressure.

The warm liquid ammonia coming from the compressor, before it enters the accumulator through the regulating valve 12 to repeat its circuit through the freezing coils, is passed v uid ammonia to the accumulator through this single valve, the proper conditions of pressure can be readily mamtained in the accumulator and cooling coils, while the liquid refrigerant will be supplied and distributed automatically by gravity and by gravity alone, from the accumulator through the header 1 to the several freezing coils accordin to the conditions and requirements in the di erent parts of the system. As freezing progresses and the ice becomes thicker on the metal sheets covering the coils, thereby retarding the transmission of heat from the water to the coils, the evaporation of the refrigerant Within the coils becomes less active; but since the temperature of the refri erant depends upon the pressure'under whic it is he d, the same or even a greater congealing eflect will be exerted upon the surrounding medium when the refrigerant is in a dense condition than when it is in a state of ebullition within the coils under the same pressure.

While the process of freezing is goin on there is always more or less evaporation 0 the refrigerant in the coils and the column of dense liquid in the accumulator and its connections with the lower ends of the coils being heavier than the column of rarefied liquic rising to the same level'within the coils, a constant circulation of the refrigerant through the coils is maintained, and since the I liquid refrigerant is held under an invariable volume of vapor or pressure and at an invariable temperaturein the coils and accumulator, it exerts a more energetic cooling effect than a corresponding as with its comparatively small amount of specific heat.

In the practical operation of this system, about the same quantity of ice is finished and taken out of the freezing tank every day, so that While the finished product is being removed from. certain parts, the process of freezing is at different stages of progress in other parts of the tank, resulting in a more or less active evaporation and circulation of the refrigerant in such parts. Nevertheless, the aggregate evaporation in the entire system remains ractically constant, and therefore, the supp y of li uid refri erant to all the active freezing 00' s should e uniformly maintained.

It follows that the means and method of forecooling the liquid refrigerant while it is held under high pressure to the temperature of the refrigerant contained in the accumulator before it is admitted into the accumulator, the regulation or control of the supply of such refrigerant to'the accumulator by a single valve and the automatic distribution and supply of the liquid refrigerant under low pressure 'to the several active freezing coils, according to varyin conditions and demands, by gravity an by gravity alone, are essential distinctive features of the present invention. a

When the ice has attained the desired thickness, say 12 to 14 inches, in certain parts of the freezing tank, it is liberated by admitting gas under-pressure through the valves 4 into the correspondin coils 4,, after the cocks at and 0 have b'eenc osed to shut such coils off from the accumulator. The coils and thin metal sheets 3' covering them, are thus warmed by the gas, which is in turn cooled and liquefied. Instead of returning this liquefied gas to the suction side of the compressor, and thereby obstructing its ac tion in connection with other arts of the system, it is discharged by sligi ftly opening the valves it intothe manifold Z, and thus utilized under the conditions of pressure and temperature therein maintained, to supply the cooling coils which remain in operation.

To detach the ice cakes from the bottom and sides of the tank k to which they are also frozen, hot air is admitted to the adjoining passages 00 from the supply duct 2 by opening the proper valves y. The parts of the metal tank to which the ice cakes adhere are thus warmed sufficiently to release said cakes and permit their removal. As soon as, or even before, the ice cakes are removed, the process of freezing is resumed in those sections or parts of the tank from which the cakes are taken, by simply opening the cocks at and 0, after closing the valves 4 of the corresponding' coils. While the cakes are being removed, an equivalent volume of water is supplied to the tank from the forecooler r or a cold water reservoir through the header 9 and hose attached to one or more of the valveslO.

During the process of freezing, the water in the several parts of the tank is continuously agitated by forcing compressed air into it near the bottom of the tank through the pipes 11. This prevents impurities which are eliminated by the freezing process from adhering to the ice cakes-and becoming embedded therein, and as a result, a crystal clear product is obtained from water which has not been subjected to distillation or filtration. To render this agitation uniform throughout the freezing tank, the water in the several sections or parts of the tank,

which are separated from each other by the formation of the ice, is kept at the same level by means of the connecting pipe 5 and its branches 6, which communicate with said sections orspaces midway between the coils where no ice is formed. Without these connections the water would assume different 'levels in different parts of the tank, on account of the expansion which takes place' .with the formation of the ice and its varying thickness at different stages of its formation. Any material variation in the water level in theseveral parts of the tank would prevent uniform agitation of the water through which the air discharged into it takes the, course of least resistance, and would result in lack of uniformity in the purity of the ice, since greater agitation would take place in those in the apparatus herein shown and described may be utilized for other purposes than making ice, as for example, by omitting the freezing tank in which the cooling coils are placed, said coils either with or without the metal sheets 7' attached thereto, or evaporation chambers of any suitable form, may be used to cool the surrounding air or other mediums or substances for cold storage rooms or other purposes, the effect of variations in the temperature of the air or other mediums or substances surrounding or adjacent to the cooling coils upon the operation of the apparatus being the same as variations in the temperature of water in contact with said coils in the production of ice, as herein explained.

An suitable apparatus for recondensing or re iquefying the gas after it has been evaporated in the freezing or cooling coils orchambers and returning the same in a liquid.

state to the accumulator may be used.

Instead of warming the metal tank is to detach the ice therefrom by means of hot air, any other suitable means may be provided in the space between the tank and its insulation jacket or casing. In short, various changes in details of construction and arrangement of parts may be made to adapt the apparatus to the various purposes to which it is applicable without materially affecting its operation and without departing from the principle and intended scope of my.

invention.

When in the claims a freezing coil or chamber is mentioned it is to be understood as including one or more freezing coils or chambers.

It is to be clearly understood that a distinctively novel feature of the invention is cooling the refrigerant while held under the high pressure of the system to the temperature of the refrigerant in the accumulator held under the low pressure of the system, so as to bring the refrigerant into condition to flow by gravity from the accumulator to and through the freezing coil or chamber.

I claim:

1. In a refrigerating apparatus, an accumulator, a freezing coil or chamber having a gravity inlet connection from the accumulator and an outlet connection therewith, a supply connection from a liquefying apparatus for the refrigerant to the accumulator, means in the supply line for releasing the refrigerant from high to low pressure, and means where by the refrigerant while held under the high pressure of the system may be given the temperature of the refri erant in the accumulator held under the ow pressure of the system.

2. In refrigerating apparatus the. combination with liq uefying apparatus, of an accumulator, which has a gas outlet connection with the suction side of the liquefying apparatus and a supply connection with the discharge side of said apparatus, a coollng coil or chamber having a gravity inlet connection from said accumulator and an outlet connection therewith, said su ply connection being provided with a valve for releasing the refrigerant from high to low pressureand arranged to be ex osed to the gas on its return to the lique ing apparatus from the cooling coil or chamber to give to the refrigerant while held under the high pressure of the system the temperature of the refrigerant in the accumulator under the low pressure of the system.

3. In' refrigerating apparatus the combination of an accumulator havinga su ply connection provided with a valve for re easing the refrigerant from high to low pressure, a gas outlet connection leading from the upper part of the accumulator, a plurality of cooling coils'or chambers arranged at substantially the same level with one another, a header having a gravity-inlet connection with said accumulator; the lower portions of the coils being connected with said header and the-upper nections with t e accumulator, and means whereby the refrigerant while under the high pressure of the system may be iven the temperature of the refrigerant held at the low pressure of the system within the accumulator.

4. In refrigerating apparatus the combination with liquefying apparatus, of an accumulator having a gas outlet connection leading from the u per part thereof to the suction side of the iquefying apparatus and a refrigerant supply connection with the discharge sideof said apparatus leading through and exposed to the gas in the upperpart of the accumulator and provided with a controlling valve after its passage through the same, and one or more cooling coils or chambers each having a gravity inlet connection with said accumulator and an outlet connection therewith above its inlet connection, substantially as escribed.

5. In refrigerating apparatus the combination with a compressor, of an accumulator having gas return and refrigerant supply connections with said compressor, means in the supply connection for releasing the reortions having outlet consystem, the header having a gravity suplp frigerant from high to low pressure, means whereby the refrigerant While held under the high pressure of the system may be given the temperature of the refrigerant in the accumulator under the low pressure of the y connection with the accumulator; a plura lty of freezing coils or chambers the lower parts of which are connected with said header and the upper parts of which have outlet connections with the accumulator, sto cocks in the connections of said coils or c ambers with said header and with the accumulator, direct valvecontrolled connections between the several coils or chambers and the compressor, 15 and a freezing tank containing said coils or chambers, substantially as described.

In witness whereof, I hereto affix my signature in presence of two witnesses.

HERMANN RASSBACH.

Witnesses:

H. H. BERGMANN, GEORGE M. EMMERIoH.

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