SHAFT RH 0909040 - Caterpillar

Illustration 1 g00291419
(6) Evaporator. (7) Expansion valve. (9) Thermal tube. Evaporator (6) is a heat exchanger. The exchange of heat is accomplished by absorbing heat from the air in the cab (the target). The heat is then transferred to the air conditioner refrigerant. This is done so that latent heat of evaporation is obtained in evaporator coil (6). This process changes the refrigerant to a vapor of low pressure and low temperature. A uniform transfer of heat is required between the target and the refrigerant. Therefore, the surface area for heating air is enlarged by fins which are provided on the outer surface of evaporator (6). The amount of refrigerant that is supplied to evaporator (6) is adjusted by expansion valve (7). This valve has been described earlier. In order to make precise adjustment, evaporator (6) requires less of a drop in refrigerant pressure. Therefore, decreasing the drop in pressure is one element that fully utilizes the ability of evaporator (6).