System for producing cleansing foam - having twin piston pneumatically operated to pump liquid followed by air injection

摘要

Foam is produced in liquids esp. water to which chemicals have been added using a pair of cylinders joined by a common piston. These pumps from a ring main via non-return valves which allow suction and exhaust into a common main. Air is then injected into this main to create the foam. The piston action is controlled by air valves on a compressed air distribution system. Limit switches sense the motion of the piston and arrange for the air signal to turned over by a slide valve. The reciprocating action ensures a smooth delivery since each cylinder discharges alternately as the other draws in a charge. For use in preparing a jet of cleansing foam esp. for cleaning butcheries and butcher's implements to remove fatty deposits and odorus materials. The system provides continuous jet without the use of injectors.