| abstract |
The cavity of a formwork body (1) wherein the inside of an outer shell (6) provided with a sealable cavity is heated to a designed temperature range higher than the melting point of sulfur is fully packed with a sulfur-containing material. As the sulfur-containing material becomes cold and thus shrinks within the cavity as described above, a lid is put on the top opening (11). Thus, the inside becomes sealable and a definite pressure is applied thereto. At the same time, replenish sulfur-containing material contained in a replenish tank (2), the inside of which has been heated to the designed temperature range as described above, is supplied into the cavity due to the pressure applied to the above-described replenish tank (2). |