A Practical Manual On Sea Water Distillation
With A Description Of The Necessary Machinery For The Process

WORKING OF A DISTILLING APPARATUS. 165 in the pipe supplying exhaust steam to the evaporator, and 150 lbs. pressure in the pipe supplying steam to the pump. This is on large ships. On small ships the evaporator receives live steam. (2) Secondary Steam Pressure—0'5 lb. per square inch in evaporator case is led into the distiller. The distiller is, however, required to work sometimes below atmo- spheric pressure, and the vacuum or minus pressure in the distiller into which the secondary steam is discharged may then amount to 18 inches. (3) Pump Speed—Piston is not to travel more than 100 feet per minute, nor make more than 60 double strokes per minute, and crank revolutions not more than 60 per minute. (4) Evaporator to be charged and fed with sea, or salt, water at a “ density” of (See observations, p. 25.) (5) The brine in the evaporator to have a “ density ” between and (See observations, p. 25.) (6) The brine to be discharged at least 30 feet above the bottom of the evaporator. This is on large ships. (7) The water diluting the brine must be at least twice the quantity of the brine. (8) The temperature of the condensed primary steam is not to exceed 150° when it is discharged from the apparatus. That would mean after its heat has been used in the evaporator feed-water heater. (9) The circulation water is not to have any head over the suction—i.e., it is not to flow into, but be sucked up by the pump. (10) The inlet circulation water is to have a temperature of 85°. (11) The evaporators are not to be lagged during the trials.