A foam generating apparatus is disclosed which generates foam from a foamable liquid by pumping the liquid by means of a high pressure pump from a storage tank to a combining device in which the liquid is combined with compressed air. The apparatus is capable of both operation and storage under extremely cold ambient conditions without the components of the apparatus becoming frozen. When the apparatus is not generating the product foam, a foamable liquid is recirculated throughout the apparatus to prevent the components of the apparatus from becoming frozen. The recirculation system is especially useful in preventing the high pressure pump from becoming frozen during storage in cold environments, while also reducing the amount of wear on the pump.
A method for controlling and/or eliminating harmful lawn grass insects is disclosed, which comprises: foaming a surfactant composition having a total content of components present of from 0.2 to 50% by weight and comprising at least one surfactant selected from an anionic sulfonate, a higher fatty acid containing from 8 to 30 carbon atoms and salts of the higher fatty acid and a thickener; and applying the foam onto the surface of lawn grass in a thickness effective for controlling and/or eliminating the harmful lawn grass insects.
Low-pressure gas is mixed in a viscous material. The flow of the gas can be easily controlled so that the dispersion of the mixing ratio of the viscous material to the gas may be confined within a small tolerance and fine bubbles may be uniformly distributed in the interior of the viscous material. The gas is mixed in the viscous material by a first pump, from which a mixture of the gas and the viscous material is delivered. Pressure is applied to the mixture by a second pump. The gas is distributed in the interior of the viscous material by allowing the mixture under pressure to pass through a conduit assembly. The viscous material is foamed when the mixture is discharged from a nozzle through a discharge pipe.
A piston pump has a piston and cylinder, the piston being adapted to reciprocally move within the cylinder to effect a suction stroke and discharge stroke. A gas is supplied into the cylinder during and/or after the suction stroke of the piston pump, and a high-viscosity material is supplied into the cylinder after the suction stroke. A discharge stroke of the piston pump is effected after completion of supply of the high-viscosity material in the cylinder to thereby discharge the gas and high-viscosity material into a pipe. A first step introduces a high-viscosity material into a gas, a second step pressurizes, by a pump, a combination of the high-viscosity material and the gas transferred from the first step, a third step passes the combination in a pressurized state through a dispersing pipe to disperse the gas into the high-viscosity material to produce a mixture, and a fourth step discharges the mixture to effect foaming. Use is made of piston pumps 45A and 45B, each including a cylinder and a piston which reciprocally moves within the cylinder to effect a suction stroke and discharge stroke, and a membrane gas generator 10 to which compressed air is supplied to generate a gas. A low-pressure gas generated by the membrane gas generator 10 is supplied into each piston pump and the high-viscosity material is introduced into the gas.
A piston pump has a piston and cylinder. A gas is supplied into the cylinder during and/or after a suction stroke of the piston pump, and a high-viscosity material is supplied into the cylinder after the suction stroke. A discharge stroke of the piston pump is effected after completion of supply of the high-viscosity material to thereby discharge the gas and high-viscosity material into a pipe. Use is made of piston pumps 45A and 45B, each including a cylinder and a piston which reciprocally moves within the cylinder to effect the suction stroke and discharge stroke, and a membrane gas generator 10 to which compressed air is supplied to generate a gas. A low-pressure gas generated by the membrane gas generator 10 is supplied into each piston pump and the high-viscosity material is introduced into the gas.
Apparatus for generating foam for use in fire fighting having two plates housed in a chamber which respectively introduce pressurized air and a water/surfactant solution between the two plates where foam is generated and emitted from an aperture on the side of the chamber. The pressurized water/soap solution enters the chamber through an orifice in one plate. Pressurized air enters the chamber through a number of channels bored through the other plate, such channels appearing in an annular groove which circumscribes the water inlet. The plates are provided with surfaces which are brought together to form a restricted area therebetween. The restricted area balances the pressure between the incoming water and the incoming air by achieving an equilibrium at some particular radius out from the center of the two plates. This equilibrium radius moves in and out from the center as necessary to keep the two pressures balanced. The apparatus also includes a pressure regulating system that automatically cuts off the flow of pressurized water and air when the foam dispensing nozzle is turned off.
