PURPOSE: To enable regeneration of the grease filter stuck with oils and fats, etc., without damaging color and adsorptivity, etc., by heat-treating the combustibles stuck on the ceramic filter for a ventilation fan in the heat-treating furnace under oxidative atmosphere having a specified oxygen concn. or over.
CONSTITUTION: The combustibles stuck on the ceramic filter for a ventilation fan is burned and removed by a heat treatment under oxidative atmosphere having ≥10vol.% oxygen concn. in the heat-treating furnace while traveling or standing. The heat treatment is kept at temp. within a 400-800°C range preferably, and the filter has the heat resistance to above treating temp. By this way, short time treatment is possible at relatively low temp., and perfect regeneration is possible because almost org. material stuck is removed as combustion gas.
SHIMAZAKI KATSUNORI
YAMANE AKIYOSHI
