Failure to obtain full rated capacity is one of the most frequent troubles encountered during operation of a distilling plant. The trouble may be very difficult to remedy since it may result from a combination of things. Following are the various factors which promote full output of the distill-ing plant. Any variations of these may cause a decrease in the plants efficiency.

1. Proper steam pressure above the orifice.

2. Highest possible vacuum in the first-effect tube nest.

a. No air leaks

b. Proper water levels in the evaporator shells.

c. Evaporator tube nests continuously vented.

d. Evaporator tube nests reasonably clean.

(1) Continuous feed treatment.

(2) Tubes mechanically cleaned when necessary.

e. Density of brine overboard not over 1.5/32.

(1) Overboard piping reasonably clean.

(2) Proper valve settings.

(3) Proper operation of brine pump

(clean piping and strainers, proper speed and direction of rotation, pump properly vented, gland properly vented, gland properly packed and sealed, no air leaks in piping).

f. Tube nests properly drained.

(1) Proper operation of all drain regulators.

(2) Proper operation of the tube nest drain pump.

3. Highest possible vacuum in the last-effect shell.

a. No air leaks.

b. Proper air ejector operation.

(1) Clean nozzle and strainer.

(2) Steam at the required quality and quantity.

c. Ample flow of circulating water.

(1) Clean strainer, pipeline, and tubes.

(2) Proper valve settings.

(3) Proper operation of the circulating pump.

d. Effective surface in the distilling condenser. tubes.

(1) No undue deposits inside the tubes.

(2) Proper venting of the condenser

(3) Proper operation of the condensate pump.