Modular balanced foam flow system

An apparatus in which metered quantities of a liquid chemical foamant are injected into a plurality of conduit assemblies conveying a water stream so as to maintain a desired concentration of said chemical foamant in said water stream, comprising:

• a tank for holding a quantity of said liquid chemical foamant;
• a plurality of rotary gear foam pumps each having an inlet port coupled to said tank and an outlet port coupled to one of said plurality of conduit assemblies;
• a plurality of hydraulic motors each connected in driving relation to one of said plurality of rotary gear foam pumps;
• a plurality of valves each coupled with one of said plurality of hydraulic motors and a source of pressurized hydraulic fluid;
• a plurality of first sensors each operatively coupled to one of a plurality of said conduit assemblies to sense the rate of flow of a water stream flowing through said one of a plurality of conduit assemblies and producing a plurality of first signals representative of said water flow rate in each of said conduit assemblies;
• a plurality of second sensors each operatively coupled to one of a plurality of conduit assemblies adjacent to said outlet port of each of a plurality of rotary gear foam pumps to sense the pressure of both the water and foam chemical stream flowing through each of said plurality of conduit assemblies and producing a plurality of second signals representative of said water and foam chemical pressure in each conduit assembly;
• and
• a plurality of control systems each one responsive to said plurality of first signals and said plurality of second signals for producing a plurality of electrical signals each one for controlling a speed at which one of said plurality of hydraulic motors is driving one of said plurality of rotary gear foam pumps, such that a desired quantity of the liquid chemical foamant in the water stream exiting said plurality of conduit assemblies maintains said desired concentration.