An apparatus for continuously generating and controlling the density of foam has a fluid in-flow manifold in communication with a source of liquid and comprising a pressure sensor. A plurality of branch lines are in fluid communication with the in-flow manifold a foam out-flow manifold. Each branch line has a flow control valve, a Venturi tube and in fluid communication with a throat of each Venturi tube an air induction control valve. The foam out-flow manifold has a pressure sensor. At least one in-flow control valve is disposed between the source and the in-flow manifold and at least one out-flow control valve is in communication with the out-flow manifold. The branch valves, air valves, the in-flow control valve and the out-flow control valve are operable to provide a chosen flow rate of the liquid and a selected foam product flow rate at a selected density of the foam product.

The invention is directed to a Venturi tube comprising: a cylindrical tube, wherein a first cone and a second cone are arranged. The first cone and the second cone are configured so that their bases face each other and are separated by a gap. A suction tube has an inlet and an outlet. The inlet is located outside of the cylindrical tube and the outlet is located between the first base and second base, i.e., the gap between the first base and the second base. The Venturi tube of this structure serving as a gas-liquid mixer will have higher gas solubility. The Venturi tube of this structure has a shorter length than traditional ones while processing the same amount of liquid and thus requires lower manufacturing cost.

An apparatus for continuously generating and controlling the density of foam has a fluid in-flow manifold in communication with a source of liquid and comprising a pressure sensor. A plurality of branch lines are in fluid communication with the in-flow manifold a foam out-flow manifold. Each branch line has a flow control valve, a Venturi tube and in fluid communication with a throat of each Venturi tube an air induction control valve. The foam out-flow manifold has a pressure sensor. At least one in-flow control valve is disposed between the source and the in-flow manifold and at least one out-flow control valve is in communication with the out-flow manifold. The branch valves, air valves, the in-flow control valve and the out-flow control valve are operable to provide a chosen flow rate of the liquid and a selected foam product flow rate at a selected density of the foam product.

An apparatus for continuously generating and controlling the density of foam has a fluid in-flow manifold in communication with a source of liquid and comprising a pressure sensor. A plurality of branch lines are in fluid communication with the in-flow manifold a foam out-flow manifold. Each branch line has a flow control valve, a Venturi tube and in fluid communication with a throat of each Venturi tube an air induction control valve. The foam out-flow manifold has a pressure sensor. At least one in-flow control valve is disposed between the source and the in-flow manifold and at least one out-flow control valve is in communication with the out-flow manifold. The branch valves, air valves, the in-flow control valve and the out-flow control valve are operable to provide a chosen flow rate of the liquid and a selected foam product flow rate at a selected density of the foam product.

An apparatus for continuously generating and controlling the density of foam has a fluid in-flow manifold in communication with a source of liquid and comprising a pressure sensor. A plurality of branch lines are in fluid communication with the in-flow manifold a foam out-flow manifold. Each branch line has a flow control valve, a Venturi tube and in fluid communication with a throat of each Venturi tube an air induction control valve. The foam out-flow manifold has a pressure sensor. At least one in-flow control valve is disposed between the source and the in-flow manifold and at least one out-flow control valve is in communication with the out-flow manifold. The branch valves, air valves, the in-flow control valve and the out-flow control valve are operable to provide a chosen flow rate of the liquid and a selected foam product flow rate at a selected density of the foam product.