Patent GB-531631-A (GB)
Title: Improved heating and refrigerating apparatus
IPC: F25B9/06
Filed: 1939-07-07
Abstract: 531,631. Compressing air and gases. SPLADIS SOC. POUR L'APPLICATION D'INVENTIONS SCIENTIFIQUES. July 7, 1939, No. 19851. Convention date, Oct. 10. 1938. [Class 8 (i)] [Also in Groups XIII; XXVI and XXXV] In a heating or cooling process a gaseous working fluid passes through a compressionexpansion cycle the low pressure of which is at least as high as 20kg/cm2. Dry air or gas or a liquid in air or liquid in gas emulsion may be used. As shown applied to the heating or cooling of compartments 15, 16, 17, Fig. 1 of a railway truck 18 heat exchangers 12, 13, 14 are arranged in the compartments and air supplied at 27, 28, 29 is passed over the heat exchangers and withdrawn through suction funnels 30, 31 32. For heating the compartments the cycle is as shown by the full arrows in Fig. 1. Air supplied to a pipe 70 is compressed by the compressor 11 and passes by pipe 164, passage b of a multiple reversing cock 23, pipe 165, regulating cock 35 and pipe 166 to the radiators 12, 13, 14, where it gives up the heat of compression to the compartments. Thence it passes by pipes 173, 174, passage c of the reversing cock and pipe 175 to a heat exchanger 22 in which it heats air supplied to the inlets 27, 28, 29 of the compartments. The working fluid then passes by pipe 176, passage d of the reversing cock and pipe 178 to an expansion motor 20 which helps to drive the compressor 11. The cooled air passes by pipe 73, passage e of the reversing cock and pipe 180 to a heat exchanger 19 placed above the truck where it absorbs heat from the atmosphere and passes through pipes 181, 182, passage f of the reversing cock and pipes 183, 184 to a heat exchanger 21, where it absorbs heat from the air sucked out of the compartments 15, 16, 17 at 30, 31, 32. From the heat exchanger 21 the working fluid passes through pipe 185, passage a of the reversing cock and pipe 187 back to the pipe 70, when the cycle recommences. A fan 33 draws in air through the heat exchanger 22, pipe 189 passage g of the reversing cock and pipe 190 and supplies the warm air to the inlets 27, 28, 29 while air is withdrawn from the compartments by a fan 34 and passed by pipe 195, passage h of the reversing cock and pipe 196 to the heat exchanger 21 giving up its heat to the working fluid passing to the compressor before being exhausted into the atmosphere at 197. For cooling the compartments the cock 23 is turned through 45 degrees by the handle 24 to reverse the cycle, the working fluid and ventilation air then flowing as shown by the dotted arrows in Fig. 1. From the compressor the air passes by pipes 164, 202 to the heat exchanger 19 where it is cooled, and thence to the heat exchanger 22 where it is further cooled by air withdrawn from the compartments and to the motor 20. The expanded air passes by pipes 179, 206, regulating cock 35 and pipes 166 to the heat exchangers 12, 13, 14 thus cooling the compartment. The air returns to the inlet pipe 70 of the compressor 11 through the heat exchanger 21 where it cools air supplied by the fan 33 to the compartments. The degree of heating or cooling can be regulated by the cock 35 which byepasses part of the working fluid. For regulating the pressure on the inlet side of the compressor a manometer 106, Fig. 10, connected to the pipe 70 operates a reversing switch 122 so that on fall of pressure a motor 141 is started and drives an auxiliary pump 25 in a direction to supply air to the pipe 70. On rise of pressure the motor is driven in the reverse direction and exhausts air from the inlet pipe 70. A further manometer 107 connected to the high pressure side 71 of the compressor 11 operates a reversing switch 122<SP>1</SP> for a motor 143 which through a worm 102 and worm wheel 101 adjusts the timing cams of the expansion motor 20 this regulating the pressure. A control member 145, for selecting the required temperature of the compartments and maintaining this temperature comprises a semicircular series of contacts 147, 148, 150 any of which can be connected with a segment 158 by a brush 159 on an arm 160 turned through gearing 166 by a thermostat 144 in the compartment and having a pointer 162 moving over a scale 163. Two semicircular contacts 152, 153 rest upon the contacts 147, 148, 150 and are carried by an insulating piece 154 adjustable by a handle 155 over a scale of temperatures 157. On moving the segments 152, 153 by the handle 155 from the position shown (to alter the temperature) current from a main 135 passes by lead 161 segment 158, brush 159 and segment 145 or 150 to relay 131 or 132 to start a reversing motor 129 to turn a worm 120 gearing with a nut 119 on the manometer 107 so that the reversing switch 122<SP>1</SP> is actuated to start the motor 143 and adjust the timing of the valves of the expansion motor 20 in the required direction to increase or decrease the high pressure and hence the temperature of the compartments. The thermostat 144 then turns the arm 160 until the brush 159 engages the contacts 147 which are opposite the gap between the segments 152, 153 whereupon the relay 131 or 132 is de-energized. Upon variation of temperature in the compartment the brush 159 moves to contacts 147 which are engaged by the segments 152 or 153 and the relay 131 or 132 is energized to keep the temperature constant. A reversing switch 146 which may be interconnected with the reversing cock 23 reverses the relays 131, 132 when the apparatus is changed over from heating to cooling. For starting, the motor 141 of the auxiliary pump 25 is connected by a switch 199 to mains 200, 201. The compressor 11 comprises three radial cylinders 37, 38, 39 between which are the radial cylinders 40, 41, 42 of the expansion motor 20, the connecting rods being connected to a crank on the shaft 48 of which is an electric motor supplying the difference between the power of the compressor and the expansion motor. Inlet valves 55 are arranged in the pistons 43 of the compressor and exhaust valves 50 in heat insulating blocks 49<SP>1</SP> forming the cylinder heads. Admission and exhaust valves 59, 60 for the motor are controlled by cams driven by the shaft 48 through planet gearing mounted on the worm-wheel 101, Fig. 10, whereby the timing is adjusted by the manometer 107, thermostat 144 and controller 145. The compressor 11 is provided with a safety valve 212. Instead of regulating by adjusting the motor valves the compressor valves may be similarly adjusted. To prevent the formation of frost a thermostat may act on the valve 212 to reduce the cooling or the path of the handle 155 of the controller 145 may be limited on the low temperature side. At very high pressure the external faces of the pistons may be subject to fluid at a medium pressure to reduce losses. Specification 12918/01, [Class 8], is referred to. Packing material in the nature of photographic film, untanned hide &c. as set forth in French Specification 632,537 may be used in the pistons, and the connecting rods may be of the construction set forth in French Specification 437,491.