except that it is installed with refrigerators of not over 20 cubic feet contents. The refrigerating element consists of the brine tank, the expansion coils inside the brine tank, the expansion valve, the thermo-coil and the thermostat. Eighteen standard sizes of brine tanks are made, one of which is shown in Fig. 103 and tit practically all ice chambers. <Callout type="important" title="Important">The brine tank is essential for maintaining consistent temperatures within the refrigerator.</Callout> The brine tank is of sheet copper tinned on the outside. It has two to four freezing compartments, according to the tank size. Each 21-cube tray will freeze two and one-half pounds of ice, while the large tray will freeze an eight and one-half pound cake of ice. The tank is filled with a solution of calcium chloride. Expansion coils are placed in the tank in such a way as to surround each freezing compartment. The liquid refrigerant is admitted to the expansion coils through an automatic expansion valve which lowers its pressure from two inches of vacuum to three pounds per square inch, depending on the size of brine tank and number of feet of tubing in the expansion coil. The valve is of the balanced pressure type. Increasing pressure on the low side caused by the boiling refrigerant, acts against the pressure on the liquid side and automatically shuts off the supply of liquid when sufficient has been admitted. The valve automatically opens when the suction of the compressor sufficiently reduces the pressure on the low side. <Callout type="risk" title="Risk">Improperly managed expansion valves can lead to over-refrigeration, damaging food.</Callout> FJG. 104.— KELVINATOR CONDENSING UNIT. The system is automatically controlled by the thermostat placed within the thermo-coil on top of the brine tank. The thermostat opens and closes the motor circuit as the temperature within the refrigerator falls and rises. It is of the sylphon type, a corrugated metal bellows filled with sulphur dioxide, which by the contraction and expansion caused by changing temperatures operates the quick make and break switch. <Callout type="tip" title="Tip">Thermostats should be regularly checked for proper operation to ensure consistent cooling.</Callout> The actual running time of Kelvinator will vary, of course, with the room temperature, the quality and degree of refrigerator insulation, the size of refrigerator, etc. Under ordinary conditions, however, the machine will run 6 or 7 hours a day. COMPRESSION REFRIGERATING MACHINES 245 The box temperatures will be at least 10° colder than ice would keep the same box. The reason for this is that the surface of the brine tank is kept constantly at 20° to 22° while the surface of a cake of ice is 32° F. Fig-. 104 shows the condensing unit Model 12800. This unit includes a yi hp. motor driving a reciprocating type, single-cylinder compressor by means of a "V" type belt. The condenser is made of finned tubing. It is cooled with forced air circulation. A small receiver is used. The weight of this unit is 80 pounds. This unit is supplied with a special steel cabinet. Fig. 105. The food storage space is 4.7 cubic feet and 7 square feet shelf area. The exterior is gray lacquer on steel. The lining <Callout type="gear" title="Gear">The special steel cabinet ensures durability and protection for the refrigeration unit.</Callout> is white enamel on g-alvanized iron. The hardware is nickel-plated brass. The insulation is corkboard. The dimensions of the cabinet are : Width Depth Height Overall 26J^ in. 22i4 in. 56^/^ in. Food Compartment 22 in. 15Ji in. ZAy^'in. Condensing Unit Compartment 26^ in. '9^-2 . 16^2 in. The cooling unit has two 15-cube ice trays. The shipping weight of this unit is 300 pounds. Fig. 106 shows the type LB large capacity air-cooled condensing unit. The compressor has one cylinder and is of the vertical, reciprocating, single-acting type. A ^4 hp. motor drives the compressor by means of a "V" type belt. The condenser is of the radiator type. It is cooled by forced air circulation, from the fanned motor pulley. The wattage is approximately 800 at rated capacity. A similar larger type BB, Fig. 107, is manufactured. The compressor has two cylinders. A 1^ hp. motor is used. The wattage of this model is approximately 1200 at rated capacity. Both of these units have extensive use for apartment house installations. Kold King. — Fig. 108 shows the household refrigerating machine manufactured by the Kold King Corporation at Detroit, Mich. It is reported this company is out of business. <Callout type="warning" title="Warning">Discontinued models may lack support and spare parts.</Callout> A single-cylinder sulphur dioxide compressor is used. The condenser is air-cooled and consists of sixty feet of copper tubing
Key Takeaways
- Brine tanks are crucial for maintaining consistent temperatures.
- Expansion valves control the flow of liquid refrigerant.
- Thermostats regulate the motor circuit based on temperature changes.
Practical Tips
- Regularly check and maintain thermostats to ensure proper operation.
- Use appropriate expansion valves to prevent over-refrigeration and food damage.
- Ensure that cabinets are well-insulated to maximize energy efficiency.
Warnings & Risks
- Discontinued refrigerators may lack support for repairs or spare parts.
- Improperly managed expansion valves can lead to over-refrigeration, damaging food.
- Thermostats should be regularly checked and maintained for consistent cooling.
Modern Application
While the specific models and technologies have evolved significantly since 1927, the principles of refrigeration remain fundamentally similar. Understanding these historical techniques provides a foundation for modern survival preparedness, especially in scenarios where access to advanced technology is limited.
Frequently Asked Questions
Q: What are the key components of a Kelvinator refrigerator?
A Kelvinator refrigerator includes a brine tank, expansion coils inside the brine tank, an expansion valve, a thermo-coil, and a thermostat. These components work together to maintain consistent temperatures within the refrigerator.
Q: How does the expansion valve in a Kelvinator work?
The expansion valve lowers the pressure of the liquid refrigerant from two inches of vacuum to three pounds per square inch, depending on the size of the brine tank and the number of feet of tubing in the expansion coil. It automatically shuts off when sufficient liquid has been admitted and opens again as needed.
Q: What is the purpose of the thermostat in a Kelvinator refrigerator?
The thermostat within the Kelvinator controls the motor circuit based on temperature changes, opening and closing to regulate cooling as necessary. It uses a sylphon type mechanism filled with sulphur dioxide to operate quickly.