Abstract: Directly prior to the supplying of the expelling pulse of compressed gas into the pump tube, the suction supply is cut off, whereby the withdrawn portion of metal is expelled into the molten metal body under the action of the sum of its own weight and the compressed-gas pulse.To ensure the accurate timing of the suction cut-off moment and the gas pulse supply, the cover of the pump has mounted therein rod valves cooperating with a floating sleeve having its float actuated by the molten metal. The cover has also mounted therein at least one electric contact probe wired into the circuit controlling the supply of compressed gas pulses. The cutting-off of the suction is effected by the molten of an inner nozzle in an outer one, the nozzles being arranged at the intersection of the suction line and the compressed gas supply line.

Abstract: In the process of melting metal, a portion of molten metal is alternately withdrawn from beneath the surface of the body of molten metal and is expelled into the lower part of a metal holding means through a pipe of a gas-dynamic pump, which pipe, fitted in a cover of the metal holding means, is mounted for axial reciprocation and angular swinging in a ball-and-socket joint to thereby enable fan-like projection of a submerged metal jet within the limits of an angle corresponding to the dimensions of the metal holding means, thus providing for effective stirring of the melt body throughout the bottom area; stepwise reciprocation of the pump pipe is effected by means of a pneumatic positioning device, and the frequency of the metal-withdrawing and metal-expelling cycles is alternated during operating process with the aid of a preset time relay.