US3013405A - Continuous air dehydration apparatus - Google Patents

Description

Dec. 19, 1961 J. Z. G. HALL CONTINUOUS AIR DEHYDRATION APPARATUS Filed June 20, 1960 M/VENTOI? JAMES Z. G.v HALL rates Patent fiice 3,013,405 Patented Dec. 19, 1961 CONTINUOUS AIR DEHYDRATIGN APPARATUS James Z. G. Hall, Vancouver, British Columbia, Canada,

assignor to General Refrigeration Engineering Ltd.,

Vancouver, British Columbia, Canada, a corporation of British Columbia Filed June 20, 1960, Ser. No. 37,270 10 Claims. (Cl. 62234) This invention relates to apparatus for dehydrating the air of an enclosed space, such as a room or rink, to lower the dew point thereof.

An object of the present invention is the provision of apparatus for lowering the dew point of air by re frigerating means without the necessity of halting the flow of air and/or refrigerant for defrosting purposes.

This apparatus is primarily designed for supplying air to curling rinks, but it may be used for circulating air to any other confined space, such as cold storages, in which the temperature of the air is lower than the outside temperature. When air is drawn in from the outside and directed into a curling rink for ventilation purposes, that air is often quite moist. The temperature in the curling rink is comparatively low so that when the moist air comes into contact with cold surfaces within the rink, moisture condenses on these surfaces. This moisture often drips down from supporting beams and the like, causing a great deal of discomfort and annoyance. Some articles or commodities When kept in cold storage must be kept dry because any moisture or condensation would be harmful.

The present invention overcomes these difficulties by means of dehydration apparatus which cools air drawn from an enclosed space, thereby lowering its dew point, said air then being returned to the enclosed space. The apparatus is essentially designed to lower the air temperature below the freezing point so that the excess moisture is removed as frost. The air returned to the enclosed space is so dry that condensation will not be created when the air comes into contact with cool surfaces, the temperature of which is above the dew point. The air may be heated before it is returned to the enclosure. One of the main advantages of this apparatus is that it functions continuously, that is, it does not have to be shut down for defrosting purposes. This apparatus is a unit including condensing coils, a compressor, and one or more motors. The heat from these elements is used to raise the temperature of the air being directed by the apparatus into the confined space.

Apparatus according to this invention comprises a pair of spaced radiation and absorption coils, pipe means extending from an end of one coil to an end of the other coil, means associated with said pipemeans for creating a resistance to the flow of fluid therethrough, a compressor having a fluid inlet and a pressure outlet, a motor connected to the compressor to drive the latter, valve means connected to the opposite end of each coil and to the inlet and outlet of the compressor, said compressor and coils forming a refrigerating system a refrigerant in the system, means connected to the valve means for operating it at intervals alternatively to connect one coil to the compressor outlet and the other coil to the compressor inlet to form one cycle and vice versa to form an opposite cycle, each coil when connected to the outlet acting as a condenser while the other connected to the inlet acts as an evaporator, and fan means for moving air directly through the coils, said air being mixed after passing through the coils, said evaporator coil removing moisture from the air passing therethrough before said air mixes with the air that has passed through and cooled the condenser coil.

An example of this invention is illustrated in the accompanying drawings, in which,

FIGURE 1 isa plan view of the dehydration apparatus with most of the top thereof removed,

FIGURE 2 is a vertical section taken substantially on the line 22 of FIGURE 1, illustrating one form of mechanism for alternating cycles of the apparatus and,

FIGURE 3 is a diagrammatic fragmentary view illustrating an alternative mechanism for alternating the cycles.

Referring to FIGURES 1 and 2 of the drawings, 10 and 11 are spaced radiation and absorption coils of any desired construction. In this example, coil 18 includes upper and lower headers 15 and 16 with a plurality of tubes 17 extending therebetween, said tubes having fins 18 mounted thereon and projecting laterally therefrom. Similarly, coil 11 has upper and lower headers 21 and 22 with a plurality of tubes 23 extending therebetween and having fins 24 mounted on and projecting laterally therefrom. These coils may be positioned relative to each other in any desired manner, but in the preferred form of the invention, they are opposed to each other and form two entrances for a plenum chamber 27 having a top and bottom 28 and 29, and side walls 31 and 32. The top, bottom and side Walls form a confining wall for the plenum chamber, and the only entrance to the latter is through the coils 10 and 11. An outlet 35 from the chamber is provided in the confining wall, such as another wall 32, as shown in FIGURE 1. Water is drained from chamber 27, and holes 36 may be provided in bottom 29 for this purpose.

Air is moved through coils It? and 11 into the chamber in any convenient manner. The preferred way is to provide a fan 37 in the outlet 35, said fan being mounted on the drive shaft of an electric motor 38 which is prefer ably located within the plenum chamber. In this example, the motor is mounted on a stand 39 which projects upwardly from the chamber bottom 29, see FIGURE 2.

A pipe 42 extends from one end of coil 10 (header 16) to an end coil 11 (header 22). Suitable means associated with or in this pipe is provided for creating a resistance to the flow of fluid therethrou-gh in either direction. A simple form of flow resister is a capillary coil or tube 44 mounted in pipe 42 so that fluid passing through this pipe moves through the capillary coil.

Coils 10, 11 and 44, and pipe 42 form part of a refrigerating system which is filledwith a suitable refrigerant. A compressor 48, preferably located in chamber 27, forms part of this system. This compressor is operated in any desired manner, such as by an electric motor 49 mounted in the plenum chamber and connected to the compressor by a beltand pulley arrangement indicated at 50. This compressor has the usual inlet and outlet for fluid to be compressed. Suitable means is provided in thisapparatus for alternately connecting the opposite ends of coils 10 and 11, that is, the ends opposite to those which are interconnected by pipe 42, to the inlet and outlet of the compressor, and vice versa. In other Words, when header 15 is connected to the inlet, header 21 is connected to the outlet, and vice versa.

It will be realized that different forms of known valve arrangements may be used for this alternate connection of the radiation and absorption coils to the compressor. In this example, a 4-way valve 55is mounted on a suitable support 56 within chamber 27. This Valve is connected by intake pipe 58 and pressure pipe 59 to the compressor inlet and outlet, respectively. The valve is also connected by flow pipes 61 and 62 to coil headers 15 and 21, respectively. Valve 55 is such that when in one position, pipe 61 is connected to the compressor inlet pipe 58, while pipe 62 is connected to compressor outlet pipe 59, at which time coil 11 acts as a condenser and coil as an evaporator, and when the valve is moved to another position, this is reversed, that is, pipe 62 is connected to pipe 58, while pipe 61 is connected to pipe 59, and at this time coil 10 acts as a condenser and coil 11 as an evaporator.

The 4-way valve 55 may be controlled in any desired manner. In this example, a solenoid pilot valve 66 is employed, this valve being mounted on support 56. A pipe 68 extends from the outlet of compressor 48 to the pilot valve, and a return pipe 69 extends from the latter to the compressor inlet. Another pipe 70 extends from the pilot valve to valve 55 to direct a working fiuid thereto. The pilot and control valves are such that when the former is closed, the latter is in one position, and when the pilot valve is opened, the working fluid moves the 4-way valve to its other setting. The working fluid is directed from and to the compressor by pipes 68 and 69. As the pilot and control valves are well known in the art, they do not need to be described in detail herein.

Pilot valve 66 is opened and closed at predetermined intervals in any desired manner. In FIGURES 1 and 2, a time clock switch 72 is mounted on support 56. This switch is connected by suitable wiring indicated at 73 to the solenoid pilot valve and to a source of electrical current, not shown. The time clock switch may be set so that it is closed for a predetermined interval of time to keep the pilot valve closed, and then the time switch is open for another predetermined interval to keep the pilot valve open.

FIGURE 3 illustrates an alternative form of mechanism for controlling pilot valve 66 in place of time switch 72. An electric switch 76 is provided, said switch being connected to the pilot valve and to a source of electrical power by a wiring system indicated at 77. This switch has an operating finger 78 projecting therefrom which may be moved laterally to open and close the switch. A pair of plates 80 and 81 are swingably suspended just inside of coils l6 and 11, respectively. Plate 80 is hingedly mounted on its upper end at 82, while plate 81 is hingedly mounted at its upper end at 83. A connecting link 85 extends between these plates and is hingedly connected thereto at 86 and S7. A lug 89 projects outwardly from this link near and in line with switch finger 78. If desired, another lug 91 may project from the link into an oil damping bath 92.

The operation of this follows:

Fan 37 is operated to draw moist air into plenum chamber 27 through coils 10 and 11, and to discharge the mixed air through outlet into a given confined area, such as a curling rink or storage compartment. This air keeps compressor 48 and motors 38 and 49 cool so that the heat from these elements is utilized to heat the air.

When pipe 61 is connected by valve 55 to compressor outlet pipe 59, and pipe 62 is connected to compressor inlet pipe 58, coil It) acts as a condenser and coil 11 as an evaporator. The compressed refrigerant is directed into coil 10 where it is cooled by the air passing through the latter. The heat given off by the condenser is absorbed by this air. The refrigerant then passes through the capillary coil 44, and as it expands in coil 11 it absorbs heat from the air passing through said coil. The temperature of this air is lowered to lower its dew point. This results in the condensation of moisture which freezes on to the tubes and fins of the coil. This cooled and dehydrated air mixed with that passing through coil 10 is directed from the plenum chamber through its outlet 35. The mixed air has a very low dew point so that condensation will not be created when it comes into contact with cool surfaces in the enclosed space.

After a predetermined interval, time switch 72 causes pilot valve 66 to reverse valve 55. At this time, pipe 62 is connected to compressor outlet pipe 59, and pipe 61 is connected to compressor inlet pipe 58. Coil 11 now dehydration apparatus is as acts as a condenser while coil 10 acts as an evaporator. In other words, the cycle has been reversed. The heat given oif by the refrigerant in the condenser coil melts the ice off the latter. The water thus formed drops off the condenser coil into the bottom of the apparatus from which it is drained through holes 36. When the refrigerant passes through coil 10 it absorbs heat from the air passing through this coil to lower its temperature and dew point. This causes the excess moisture to be deposited on the fins and tubes of the coil where it freezes, thereby dehydrating the air. Here again, the dehydrated air is mixed with air passing through coil and discharged from the plenum chamber. Thus it will be seen that this apparatus functions continuously to dehydrate the air. There is only a slight hesitation between cycle changes while the movement of the refrigerant is being reversed. Furthermore, there is no necessity to stop the apparatus for defrosting purposes.

This apparatus is mainly used in a closed circuit including the rink or storage space, the air of which is being conditioned. The temperature drop of the air taken from the space is always relative to the temperature in said space. The dew point of the air drawn into the apparatus is always lowered so that when the air is returned to the space, condensation cannot occur in the latter even when the air comes into contact with a surface the temperature of which is below that of the general space temperature. It is desirable to have the dew point of the air in the space comparatively low in order that moist air from the outside may be added to it without creating conditions that would result in condensation on comparatively cool surfaces.

The apparatus of FIGURE 3 operates in the same manner as that described above with the exception that the mechanism for operating the pilot valve 66 is changed. Assuming that coil 10 is frosted up and coil 11 has just become an evaporator, the force of the air passing through coil 11 is greater than that passing through clogged coil 10 so that plates and 81 are swung towards the latter coil. This keeps switch 76 in a position to cause valve 66 to keep valve 55 so positioned that pipe 61 is connected to compressor outlet pipe 59 while pipe 62 is connected to compressor inlet pipe 58. As ice builds up on coil 11 and melts off coil 10, the force of air through the latter will increase relative to that passing through the former. Eventually plates 89 and 81 swing towards coil 11 to allow switch 76 to reverse the cycle.

What I claim as my invention is:

1. Continuous dehydration apparatus for air from an enclosed space to lower the dew point thereof, comprising a pair of spaced radiation and absorption coils, pipe means extending from an end of one coil to an end of the other coil, means associated with said pipe means for creating a resistance to the flow fluid therethrough, a compressor having a fluid inlet and a pressure outlet, a motor connected to the compressor to drive the latter, valve means connected to the opposite end of each coil and to the inlet and outlet of the compressor, said compressor and coils forming a refrigerating system, a refrigerant in the system, means connected to the valve means for operating it at intervals alternatively to connect one coil to the compressor outlet and the other coil to the compressor inlet to form one cycle, and vice versa to form an opposite cycle, each coil when connected to the compressor outlet by the valve means acting as a condenser while the other coil connected at this time to the compressor inlet acts as an evaporator, and fan means for moving air directly through the coils, said air being mixed after passing through the coils, said evaporator coil removing moisture from the air passing therethrough before said air mixes with the air that has passed through and cooled the condenser coil.

2. Continuous dehydration apparatus for air from an enclosed space to lower the dew point thereof, comprising a closed plenum chamber, spaced radiation and absorption coils in the confining wall of the chamber and forming two entrances thereto, pipe means extending from an end of one coil to an end of the other coil, means associated with said pipe means for creating a resistance to the flow of fluid therethrough, a compressor having a fluid inlet and a pressure outlet, a motor connected to the compressor to drive the latter, valve means connected to the opposite end of each coil and to the inlet and outlet of the compressor, said compressor and coils forming a refrigerating system within the chamber, a refrigerant in the system, means connected to the valve means for operating it at intervals alternatively to connect one coil to the compressor outlet and the other coil to the compressor inlet to form one cycle, and vice versa to form an opposite cycle, each coil when connected to the compressor outlet by the valve means acting as a condenser while the other coil connected at this time to the compressor inlet acts as an evaporator, an outlet for the chamber, and fan means at the chamber outlet for drawing air directly through the coils and discharging it through the chamber outlet, said air being mixed after passing through the coils, said evaporator coil removing moisture from the air passing therethrough before said air mixes with the air that has passed through and cooled the condenser coil.

3. Continuous dehydration apparatus for air from an enclosed space to lower the dew point thereof, compris ing a pair of spaced radiation and absorption coils, pipe means extending from an end of one coil to an end of the other coil, means associated with said pipe means for creating a resistance to the flow of fluid therethrough, a compressor having a fluid inlet and a pressure outlet, a motor connected to the compressor to drive the latter, a flow pipe extending from the opposite end of each coil, a pressure pipe extending from the compressor outlet, an intake pipe connected to the compressor inlet, a valve connected to the two flow pipes and to the pressure and intake pipes, said valve being operable to connect one flow pipe to the pressure pipe and the other flow pipe to the intake pipe and vice versa, said compressor and coils forming a refrigerating system, a refrigerant in the system, means connected to the valve for operating it at intervals alternately to cause the coils to act as the condenser and an evaporator, and fan means for moving air directly through the coils, said air being mixed after passing through the coils, said evaporator coil removing moisture from the air passing therethrough before said air mixes with the air that has passed through and cooled the condenser coil.

4. Continuous dehydration apparatus as claimed in claim 1 in which the means for creating resistance to the flow of fluid through the pipe means between the two coils comprises a capillary tube through which the fluid passes when travelling from one coil to the other.

5. Continuous dehydration apparatus for air from an enclosed space to lower the dew point thereof, comprising a closed plenum chamber, radiation and absorption coils at opposite sides of the chamber and forming two entrances thereto, a pipe extending from an end of one coil to an end of the other coil, means in said pipe for creating a resistance to the flow of fluid therethrough, a compressor having a fluid inlet and a pressure outlet, a motor connected to the compressor to drive the latter, a flow pipe extending from the opposite end of each coil, a pressure pipe extending from the compressor outlet, an intake pipe connected to the compressor inlet, a valve connected to the two flow pipes and to the pressure and intake pipes, said valve being operable to connect one flow pipe to the pressure pipe and the other flow pipe to the intake pipe and vice versa, said compressor and coils forming a refrigerating system within the chamber, a refrigerant in the system, means connected to the valve for operating it at intervals alternately to cause the coils to act as a condenser and an evaporator, an outlet for the chamber between the radiator and condenser coils, and a fan at the chamber outlet for drawing air directly through the coils and discharging it through the chamber outlet, said air being mixed after passing through the coils, said evaporator coil removing moisture from the air passing therethrough before said air mixes with the air that has passed through and cooled the condenser coil.

6. Continuous dehydration apparatus as claimed in claim 5 in which the means for creating a resistance to fluid flow through the pipe between the coils comprises a capillary coil in said pipe.

7, Continuous dehydration apparatus as claimed in claim 5 in which the means for operating the valve at intervals comprises a solenoid pilot valve connected to said valve and to the compressor inlet and outlet, and means for alternately opening and closing the pilot valve at intervals.

8. Continuous dehydration apparatus as claimed in claim 7 in which the means for opening and closing the pilot valve comprises a time switch in the circuit of the solenoid of the valve.

9. Continuous dehydration apparatus for air from an enclosed space to lower the dew point thereof, comprising a closed plenum chamber, radiation and absorption coils at opposite sides of the chamber and forming two entrances thereto, a pipe extending from an end of one coil to an end of the other coil, means in said pipe for creating a resistance to the flow of fluid therethrough, a compressor having a fluid inlet and a pressure outlet, a motor connected to the compressor to drive the latter, a flow pipe extending from the opposite end of each coil, a pressure pipe extending from the compressor outlet, an intake pipe connected to the compressor inlet, a valve connected to the two flow pipes and to the pressure and intake pipes, said valve being operable to connect one flow pipe to the pressure pipe and the other flow pipe to the intake pipe and vice versa, said compressor and coils forming a refrigerating system within the chamber, a refrigerant in the system, electrically-controlled means connected to the valve for operating it at intervals alternatively to cause the coils to act as a condenser and an evaporator, a switch in circuit with the electrically-controlled means, means for operating the switch at intervals, an outlet for the chamber between the radiation and condenser coils, and a fan at the chamber outlet for drawing air directly through the coils and discharging it through the chamber outlet, said air being mixed after passing through the coils, said evaporator coil removing moisture from the air passing therethrough before said air mixes with the air that has passed through and cooled the condenser coil.

10. Continuous dehydration apparatus as claimed in claim 9 in which the means for operating the switching comprises a plate hingedly suspended in the chamber near each coil, a link connecting said plates, and means on the link for operating the switch when the plates are swung back and forth by air moving through the coils.

References Cited in the file of this patent UNITED STATES PATENTS

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