Automatic Foam Compound Induction System
A flexible automatic foam compound induction system used in many tankers used to supply deck foam monitor equipment is shown in figure below. The automatic inductor on the suction side of the pump maintains the appropriate foam liquid quantity in the water stream. Water pressure of foam liquid suction ports are provided at the side of the automatic foam inductor unit. Water under pressure from the discharge side of the pump enters the pressure port inducing foam liquid from the tank through the foam liquid suction port.
A swing paddle fitted in the body of the inductor, in the main water flow, moves backward and forward, according to the rate of flow. The paddle rotates a water metering vane in the water pressure port, bypassing water into the foam liquid port, thus diluting the foam liquid entering the water stream at the correct concentration to meet all flow conditions. The atmospheric type foam liquid tank enables the system to be replenished during operation.
“Marine Auxiliary Machinery” by H.D. McGeorge