High speed, high volume gas pulse generator

Abstract

A gas valve for providing a short duration, high volume gas pulse includes an outer chamber having an exhaust gas outlet at its front and an inner chamber which extends along the outer chamber, and terminates, at its forward end, in an opening aligned with the gas outlet of the outer chamber and spaced rearwardly therefrom. Within the inner chamber, a piston is mounted for front-to-rear reciprocal movement, and the length of the piston is selected to be greater than the distance between the valve outlet and inner chamber opening. The piston is provided with an intermediate forwardly-directed, peripheral seat, and the piston's front is dimensioned to close the exhaust gas outlet when the inner chamber is filled with gas at a moderate pressure, which forces the piston forward. The outer chamber can then be filled with a charge of gas at a high pressure. In order to fire the valve, the pressure in the inner chamber is released, whereupon the high pressure acting on the peripheral rim area of the piston urges the piston rearward. When the piston uncovers the valve outlet opening, the full pressure of the outer chamber charge acts on the front of the piston, and the piston is accelerated rapidly rearward, to fully open the exhaust gas outlet. The gas charge of the outer chamber is therefore rapidly discharged. Thereafter, the valve is once more closed by re-pressurizing the inner chamber, and the charge/discharge cycle may be repeated.