The following valves and controls are used in the hot-gas defrost systems of ammonia-type evaporators: Hot-gas or pilot-solenoid valve. The valve is a 1/8 in.…
Adual-pressure regulator is shown in Fig. 10-24. It is used on a shell-andtube cooler. The dual-pressure regulator is particularly adaptable for the control of shell-and-tube…
The constant liquid control system is a means of increasing the efficiency of a refrigeration system that utilizes air-cooled, atmospheric, or evaporative condensers (see Fig.…
The low-temperature liquid recirculating system illustrated in Fig. 10-22 uses several controls. During the cooling cycle, Number 1 pilot valve is opened and Number 2…
Bottom hot-gas feed The multiple system shown in Fig. 10-20 shows a check valve mounted in each of the liquid-refrigerant branch lines. A single solenoid…
Liquid refrigerant recirculating systems are frequently fed by upward liquid flow through their evaporators. These systems are called bottomfed. This is accomplished by either mechanical…
Gas and liquid leg shutoff Figure 10-18 illustrates a flooded floor unit suitable for operation down to ?70°F (?57°C). The gas-pressure-powered valve used in this…
Top hot-gas feed Figure 10-16 shows a modification of the system shown in Fig. 10-15. In the system shown in Fig. 10-16, top-fed hot defrost…
Bottom hot-gas feed Figure 10-14 illustrates a flooded-ceiling evaporator. Upon initiation of the defrost sequence, the hot gas solenoid (Number 1) is opened. Gas flows…
The system shown in Fig. 10-13 is similar to that shown in Fig. 10-12. However, the liquid leg of the evaporator dumps directly into the…