Method and apparatus for producing gas-filled hollow spheres

摘要

A system is described for forming hollow spheres containing pressured gas, which includes a cylinder device (14) containing a molten solid material (20) and having a first nozzle (18) at its end, and a second gas nozzle (24) lying slightly upstream from the tip of the first nozzle and connected to a source (26) that applies pressured filler gas that is to fill the hollow spheres. High pressure is applied to the molten metal, as by moving a piston (22) within the cylinder device, to force the molten material out of the first nozzle and the same time pressured gas fills the center of the extruded hollow liquid pipe that breaks into hollow spheres (12a). The environment (54) outside the nozzles contains gas at a high pressure such as 100 atmospheres, the gas is supplied to the gas nozzle (24) at a slightly higher pressure such as 101 atmospheres, and the pressure applied to the molten material (20) is at a still higher pressure such as 110 atmospheres.