Abstract: A furnace and process for carrying out the carbonizing and/or activating of charcoal and similar operations includes vent means, which may be in the general shape of one or more elongated chambers of tunnels, that acts in combination with air admission means to determine the location, size, shape, and temperature of one or more hot zones within a pile of particulate combustible material. The vent means acts to (1) expedite the venting of gases generated in the mass of particulate material being treated, (2) collect a portion of the released gases in one or more chambers or zones, and (3) provide a space to burn any combustible gases at substantially controlled temperatures and in heat transfer relationship with the particulate mass.

Abstract: A fluid filter construction comprises a mass of filtering material, such as activated charcoal, in which fluid flow passage forming members are embedded. The filtering material itself serves as the means for sealing the filter against leakage of unfiltered fluid into or out of the filter and against bypassing from the inlet to the outlet side of the filter.