US3148513A - Portable thermal unit - Google Patents

Description

Sept. 15, 1964- J. o. EWING 3,148,513

PORTABLE THERMAL UNIT Filed April 2, 1962 4 Sheets-Sheet l HHHIHHHHHHHHHHHUL James 0. E wing IN VEN TOR.

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Sept. 15, 1964 J. o. EWING PORTABLE THERMAL UNIT 4 Sheets-Sheet 2 Filed April 2, 1962 Sept. 15, 1964 J. o. EWING PORTABLE THERMAL UNIT 4 Sheets-Sheet 3 Filed April 2, 1962 James 0. Ewing INVENTOR.

oil/M FM Sept. 15, 1964 J. o. EWING PORTABLE THERMAL UNIT 4 Sheets-Sheet 4 Filed April 2, 1962 James 0. Ewing 1N VEN TOR.

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Attorneys M No mm mm *0 his! i United States Patent 3,148,513 PORTABLE THERMAL UNIT James 6. Ewing, R0. Box 6037, Nashville, Tenn. Filed Apr. 2, 1962, Ser. No. 184,273 4 Claims. (Cl. 62-160) The present invention generally relates to a portable thermal unit and specifically includes various improvements over that construction disclosed in prior Pat. No. 2,959,027, issued November 8, 1960, for Combination Evaporator-Condenser Assembly With Concentric Tubular Construction.

The primary object of the present invention is to provide a portable thermal unit having a flexible tubular concentric assembly employed as one heat exchange unit combined with a compressor unit and a second heat exchange unit together with an automatic reversing valve which is automatically controlled thereby providing for automatic cycling for maintaining the temperature of a fluid solution enclosing the flexible heat exchange unit between predetermined high and low temperatures.

Another important object of the present invention is to provide a portable thermal unit having a flexible tubular concentric heat exchange unit together with a safety pressure bypass line.

Still another object of the present invention is to provide an automatic portable thermal unit especially constructed for liquid process temperature control and includes a circulating pump which facilitates the use of the portable thermal unit of the present invention in an open sink system or jacket tank arrangement and eliminates summer-winter changeover arrangements inasmuch as the reversible compression expansion cycle employed in the thermal unit may add heat to the liquid used in the process or take heat away from the liquid thereby maintaining a temperature control automatically within predetermined high and low temperatures. The unit is also provided with a programming timer by virtue of which the unit may be placed into operation at predetermined intervals or at any given time. The unit is also provided with signal lights for indicating the phase of operation of the unit which will warn an operator that too much freshening water is being introduced into a sink system for example and will otherwise keep the operator fully informed as to the cycle of the unit.

Other features of the present invention will reside in the simplicity of construction, compactness of the components, ease of control, adaptation for various uses, simplicity of operation effected by the automatic control assembly, dependable and generally inexpensive to manufacture.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part thereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a perspective view of the portable thermal unit of the present invention illustrating the assembly thereof with an open sink or tank;

FIGURE 2 is a longitudinal sectional view of the cabinet illustrating the compressor assembly, the control assembly and the heat exchange unit disposed in the cabinet;

FIGURE 3 is a top plan view with the cabinet illustrated in section and disclosing further structural details of the assembly;

FIGURE 4 is a detailed sectional view taken substantially upon a plane passing along section line 44 of FIGURE 2 illustrating the construction and assembly of the reversing valve;

FIGURE 5 is a detailed sectional view taken substantially upon a plane passing along section line 5-5 of FIGURE 3 illustrating the T-connection and restrictor tube associated therewith;

FIGURE 6 is a longitudinal detailed sectional view illustrating the construction of the flexible heat exchange unit;

FIGURE 7 is a transverse sectional view taken substantially upon a plane passing along section line 7-7 of FIGURE 6 illustrating the flexible heat exchange unit;

FIGURE 8 is a longitudinal sectional view of a connection with the heat exchange unit disposed in a cabinet; and

FIGURE 9 is a schematic view illustrating the relationship of the component parts of the portable thermal unit.

Referring now specifically to the drawings, the numeral 10 generally designates the portable thermal unit of the present invention in which is incorporated a reversible refrigeration system which includes a commercially available compressor and motor assembly 12 that may be hermetically sealed and supported on a suitable base 14. The base 14 may be of any desired construction and any suitable shock absorbing equipment may be employed in conjunction with the compressor and motor assembly. Enclosing the motor compressor unit 12 is a cabinet 16 having reversely bent end portions 18 that support and retain screens 20 and 22 respectively which form closures for the open ends of cabinet 16 but which enable circulation of air therethrough.

Also disposed in the cabinet 16 is a looped tube type of heat exchange unit generally designated by the numeral 24 and which includes fins 26 and a looped tube 28 for purposes of providing good heat exchange relation between fluid passing through the looped tubes 28 and air passing over the surfaces of the tubes 28 and the fins 26. Disposed within the casing 16 is a shroud 30 receiving a fan and motor assembly 32 for forcing air over the heat exchange unit 24. Suitable support brackets 34 are provided for the heat exchange unit 24 and also serve to support the shroud 30 in position. The motor 32 is electrically associated with the compressor and motor assembly 12 so that the motor and compressor assembly 12 and the fan motor 32 will be operated simultaneously.

Also disposed interiorly of the casing 16 is a program timer assembly generally designated by numeral 36 and a solenoid operated reversing valve generally designated by numeral 38 which is operated in response to the program timer 36. On one wall of the casing or housing 16 the program timer is mounted on a removable panel 40 as illustrated in FIGURE 1 and includes a circular dial-type indicator 42 associated with an index line 44 by virtue of which the programming of the operation of the unit may be preset. Also, signal lights 46 and 48 are mounted in the panel 4% for indicating the cycle of operation of the unit. The signal light may be of various colors to indicate to the operator the particular phase of a cycle of the unit. For example, one signal light may be blue in color to indicate that the system is in a cooling phase and a yellow signal light may be used in the other light for indicating that the system is in a heating phase or cycle. This will indicate to the operator that certain conditions exist which need correcting. For example, excessive operation in the cooling phase or cycle would indicate to the operator that an excessive quantity for freshening water is being supplied to the system.

As illustrated in FIGURE 1, the portable thermal unit is illustrated in use in combination with an open sink or tank 50 having a liquid process solution 52 therein which may be Water or any liquid desired to have a substantially constant temperature. The tank or open sink 50 is provided with a pair of adaptor nipples 54 and 56 attached thereto to which is attached flexible hoses 58 and 60 of transparent plastic material with conventional hose clamp 62 securing the hoses in fluid-tight relation thereby enabling circulation of the liquid in the tank.

The plastic tubes 58 and 60 are communicated with a motor and pump assembly 64 carried by an extension plate 66 on the base 14. The tube 58 is connected to the pump unit 64 by a short crossover tube 68 and the tube 60 is also connected with the pump unit 64 by a short tube 70. The motor and pump unit 64 is of conventional construction and circulates the liquid 52 in the tank or sink in such a manner that continuous circulation is provided during operation of the portable thermal unit. An electrical conductor 72 interconnects the motor and pump unit 64 with the electrical control for the portable thermal unit thereby operating the pump and circulating the liquid 52 during operation of the portable thermal unit.

The length and orientation of the flexible tubes 58 and may vary as may the point of connection to the open sink or tank. Preferably, the tubes 58 and 60 are constructed of transparent plastic material which are impervious to adverse action by acidic or alkaline solutions.

As illustrated schematically in FIGURE 9 and in detail in FIGURE 5, the plastic tube 58 terminates adjacent a T-connection generally designated by numeral 74 which includes a T-coupling 76 having longitudinally aligned externally threaded end portions 78 and 80 and a branch externally threaded portion 82 that is connected with a tube 84 by virtue of a clamp nut 86 and a flared end portion 88. The end portion 78 is connected to an adaptor nut 90 which is internally threaded for threaded engagement with the end portion 78. Also, the threaded nut 90 has an externally threaded shoulder 92 integral therewith and a longitudinal flared extension 94. A retainer nut 96 is internally threaded and engages the threaded shoulder 90 and has a recess 98 therein receiving a tube 100 thus sealing the tube 100 to the nut 90 and thus to the T- shaped coupling 76. A concentric tube 102 is disposed in concentrically spaced relation to the tube 100, the extension 94, the internal bore 104 of the nut 90 and the internal bore 106 of the T-coupling 76. The bore 106 terminates in a shoulder 107 which defines a bore 109 which closely receives the inner concentric tube 102 thus sealing the tube 102 in relation to the T-coupling 76 while the concentric space between the concentric tube 102 and the internal bore 106 is communicated with the bore 108 extending through the branch portion 82 for communication with the tube 84.

Communicating with the threaded end portion 80 is a tube 110 having the end portion thereof flared as at 112 for receiving an internally threaded clamping nut 114. r

The inner tube 102 extends into the tube-110 in sealed relation thereto and a short capillary tube 116 is disposed in the end portion of the tube 102 thus forming a restriction between the interior of the tube 110 and the interior of the tube 102. For rigidifying this area and forming a backing for the tube 110 and the tube 102 for retaining the capillary tube 116 in sealed relation thereto, there is provided a rigidifying sleeve 118 enclosing a portion of the tube 110 throughout the longitudinal extent and beyond the ends of the capillary tube 116. This will provide a secure and rigid assembly for supporting the capillary restrictor 116 in position and provide a sealed connection between tube 110 and the tube 102.

The tube 110 extends into a larger tube 120 as illustrated in FIGURE 8 and the terminal end portion of the tube 110 as indicated by numeral 122 is disposed in spaced relation to the internal diameter of the tube 120. The end portion of the tube 120 is provided with a reduced portion 124 which engages and is sealed to the tube 110 thus forming an expansion area in the tube 120 which is connected with one end of the tubing 28 in the heat exchange unit 24. The other end of the tubing 28 is connected with a fitting 126 on the reversing valve 38. The tube 84 is connected to another fitting 128 on the reversing valve 38. A third fitting 130 on the reversing valve 38 is communicated with a tube 132 connected with the compressor motor assembly 12 which may be considered the outlet or discharge side of the compressor unit 12. A fourth fitting 134 on the reversing valve 38 is communicated with a tube 136 extending to the inlet side of the motor compressor unit 12. A bypass line or tube 138 intercommunicates the tubes 132 and 136 respectively to provide a bypass for the motor compressor unit for purposes of safety. An adjustable needle control valve 140 is provided in the bypass line 138 for varying the pressure at which the discharge side 132 of the motor compressor unit will be bypassed back to the inlet side 136.

Disposed in the tube 60 is a sensing bulb 142 of any suitable construction and the bulb 142 is connected with a capillary tube 144 which terminates in a thermostatic control device 146, whereby the sensing bulb 142 will indicate to the thermostatic control 146 the temperature of the liquid being circulated in the tube 60 thus serving to operate the portable thermal unit accordingly. Disposed in the tube 58 is a heat exchange unit 148 which is of a flexible nature and the details of which are illustrated in FIGURES 6 and 7 respectively. The tube 102 as illustrated in FIGURE 5 continues into the heat exchange unit as illustrated in FIGURE 8 and the tube 100 is connected to a flexible tubular unit 150. The flexible tubular unit 150 is of a bellows type tube having serpentine convolutions extending throughout the length thereof and having an end cap 152 associated therewith. A protective woven screen 154 is provided on the bellows tube 150 thereby serving to protect the bellows tube 150 from damage such as puncture or the like.

The inner tube 102 extends concentrically of the bellows tube hereinafter called the outer tube 150 and a restrictor capillary tube 156 is provided in the end of the tube 102 and a short tube 158 encloses the outer surface of the tube 102 which receives the capillary tube or restrictor 156 therein. The tube 158 may be deformed peripherally inwardly as at 160 for securing the tube 158,

. tube 102 and capillary tube 156 in position. At the other end of the tube 158, a longitudinal extension tube 162 is connected to the tube 158 and a short capillary tube 164 is disposed in the end of the extension tube 162. The connection between tubes 164, 162 and 158 is similar to the connection between tubes 156, 162 and 153. The extension tube 162 terminates in spaced relation to the cap 152.

Disposed in enclosing relation to the extension tube 162 and the major part of the tube 158 is a tubular spiral coil 166 forming a capillary tube which may be in contacting relation to the flexible outer tube 150. The inner end of the coil 166 is provided with an inwardly extending end portion 168 terminating in an open end 170 interiorly of the tube 158 inwardly of the capillary tube 156 and facing capillary tube 164. Disposed in spaced relation to the open end 170 of the end portion 168 of the coil 166 is a ball check valve 172 which engages a ball valve seat formed by an inward deformation or rib 1'74 formed in the tube 158 whereby the ball valve 172 may move from a position engaging the open end 170 of the inner end portion 168 of coil 166 or a position engaging the valve seat 174 thus forming a selective closure for these two components.

FIGURE 3 discloses the manner in which the tubes 58 and 60 are closed to prevent leakage and also discloses the relationship of the components of the invention.

The reversing valve is solenoid operated and instantly reverses and is the type manufactured by Ranco Incorporated of Columbus, Ohio as Model No. V26.

The operation of the compressor unit and the heat exchange units are generally the same as that defined in prior Patent No. 2,959,027 with this construction being capable of enabling flexibility of the heating unit disposed in the concentric tube assembly and providing specific details of construction which are novel together with a novel control apparatus for the device whereby a reversing of the system is automatically carried out by a timer or programmer which also is a commercially available item.

Assuming that the refrigeration system is operating for cooling the liquid solution in the tank, the compressor unit 12 will operate and discharge hot refrigerant gas through the heat exchange unit 24 acting as a condenser for cooling liquefaction in the usual manner and then pass through the inner tubular member until it engages the ball valve 162 which will cause the liquid refrigerant to enter the open end of the spiral coil capillary tube 166 and subsequently be discharged into the end of the outer tubular member 150 whereby the expansion therein will cause absorption of heat from the liquid solution which is surrounding the flexible outer tubular member 150. The evaporated refrigerant will then pass between the tube 150 and the tube 102 back to the intake side of the compressor through the reversing valve 38 thus completing the cycle.

When employed to give up or add heat to the liquid solution, the reversing valve is oriented so that hot gaseous refrigerant will be discharged through the line 84 into the space between tubular member 102 and tubular member 100 and ultimately pass longitudinally around the exterior of the tubular member 102 whereby the exchange unit 148 acts as a condenser until the refrigerant gas is cooled and it reaches the outer end of the outer tubular member 150. The pressure and movement of the condensed refrigerant will move the ball valve 172 away from the valve seat as the refrigerant enters the end of the tubular extension 162 thereby permitting passage of the refrigerant through the restrictions 164 and 156 which maintain a pressure differential. The ball valve 172 will then normally close the open end of the capillary tube or coil 166. The condensed refrigerant will then pass through the tube 102, through the T-coupling and into the heat exchange unit 24 which then acts as an evaporator. The liquified refrigerant will be evaporated in the heat exchange unit 24 and discharged back into the intake side of the compressor unit.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows: I

1. A portable thermal unit including a reversible refrigeration system comprising a compressor having an intake and outlet, a first heat exchange unit, a second heat exchange unit, one of said units including a flexible outer tubular member and a flexible inner tubular member concentric therewith, the inner tubular member of said one unit being connected with the other heat exchange unit, a reversing valve selectively interconnecting the compressor intake and outlet with the outer tubular member of the one unit and with the other heat exchange unit, and capillary tube means intercommunicating the units and restricting flow of refrigerant so that the same may expand for absorbing heat, the outer end of the outer tubular member being closed for flow and expansion of the refrigerant from the inner tubular member to the outer tubular member, said outer tubular member being in the form of a flexible bellows member, and a protective wire woven casing enclosing the bellows member for preventing damage thereto.

2. The structure as defined in claim 1 wherein said reversing valve and compressor are thermostatically controlled, and a bypass line for the refrigerant to protect the compressor from excessive head pressures.

3. The structure as defined in claim 1 wherein said capillary tube means includes a check valve in the inner tubular member for prohibiting flow of liquified refrigerant from the outer end thereof, and a spiral capillary tube having one end communicating with the inner tubular member on the upstream side of the check valve and the other end of the tube being communicated with the interior of the tubular member for expansion of the refrigerant.

4. The structure as defined in claim 3 wherein said spiral capillary tube includes an inner end disposed interiorly of the inner tubular member on the upstream side of the check valve, said check valve being in the form of a freely movable ball valve movable between the inner end of the coil tube and a valve seat whereby gaseous refrigerant may pass outwardly between the inner tubular member and the outer tubular member and back into the interior of the inner tubular member past the ball valve for heating the outer tubular member.

References Cited in the file of this patent UNITED STATES PATENTS 2,153,335 Martin Apr. 4, 1939 2,762,209 Bennett Sept. 11, 1956 2,959,027 Ewing Nov. 8, 1960

Claims (1)

1. A PORTABLE THERMAL UNIT INCLUDING A REVERSIBLE REFRIGERATION SYSTEM COMPRISING A COMPRESSOR HAVING AN INTAKE AND OUTLET, A FIRST HEAT EXCHANGE UNIT, A SECOND HEAT EXCHANGE UNIT, ONE OF SAID UNITS INCLUDING A FLEXIBLE OUTER TUBULAR MEMBER AND A FLEXIBLE INNER TUBULAR MEMBER CONCENTRIC THEREWITH, THE INNER TUBULAR MEMBER OF SAID ONE UNIT BEING CONNECTED WITH THE OTHER HEAT EXCHANGE UNIT, A REVERSING VALVE SELECTIVELY INTERCONNECTING THE COMPRESSOR INTAKE AND OUTLET WITH THE OUTER TUBULAR MEMBER OF THE ONE UNIT AND WITH THE OTHER HEAT EXCHANGE UNIT, AND CAPILLARY TUBE MEANS INTERCOMMUNICATING THE UNITS AND RESTRICTING FLOW OF REFRIGERANT SO THAT THE SAME MAY EXPAND FOR ABSORBING HEAT, THE OUTER END OF THE OUTER TUBULAR MEMBER BEING CLOSED FOR FLOW AND EXPANSION OF THE REFRIGERANT FROM THE INNER TUBULAR MEMBER TO THE OUTER TUBULAR MEMBER, SAID OUTER TUBULAR MEMBER BEING IN THE FORM OF A FLEXIBLE BELLOWS MEMBER, AND A PROTECTIVE WIRE WOVEN CASING ENCLOSING THE BELLOWS MEMBER FOR PREVENTING DAMAGE THERETO.

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