Apparatus for liquefying meltable material

Claim 1

Apparatus for liquefying meltable material comprising a supply container adapted to be filled with a material to be liquefied, said container having a peripheral wall and a bottom wall, both of highly heat conductive material, said bottom wall having a predetermined height and being constructed by ribs crossing each other and each tapering in upward direction so as to provide in said bottom wall adjacent perforations tapering in downward direction and arranged in such a manner that the sum of the open cross-sections of the perforations at the upper face of said bottom wall is only slightly smaller than the area of said upper face and that the sum of the smallest cross-sections of the perforations is only a small fraction of the bottom face of said bottom wall; first controllable heating means in said bottom wall for maintaining the latter at the first predetermined temperature so that the material in said perforations will melt and flow in downward direction through said perforations; a collecting trough of heat conductive material arranged beneath said bottom wall and having a cavity for receiving the molten material flowing downwardly through said perforations; second controllable heating means cooperating with said collecting trough for maintaining the latter and the material in the cavity therein at a second predetermined temperature higher than said first predetermined temperature; a heat insulator sandwiched between said container and said collecting trough for preventing heat transmission from the latter to said container; and means for discharging the liquefied material from the cavity of said collecting trough.