冷涼地における牛ふん嫌気醗酵処理の実用化施設と運転管理

Abstract

1) A plant of anaerobic manure fermentation for 70 dairy cattle (converted to cow) was planned, constructed and operated.2) The press-juice of cattle feces was treated as fermentation material. A fermentation tank of 30m3 (24t juice-sludge) composed of one-tank-type was also setted. A gas holder of 10m3 and nonwater type was adopted, which consisted of specific gum-cloth.3) A sludge-circulation system was used for stirring sludge in the fermentation tank, and it was also used for heating sludge. Methane-composite gas, which was self-supplied from the plant, was utilized for heating sludge in the tank.4) The fermentation was maintained at 35-37 degrees centigrade. It was presumed that the fermentation will be effective at the more lower temperature to minimize a heat loss from the cold.5) An underground pit of manure was prepared to protect feces from freezing. But the increase of diluting water caused decrease of sludge density and organic-matter digestibility.6) The earth, sand and admixture in sludge often caused blockages of circulating pump and heat-exchanging equipment. It was necessary to exchange the equipments and to eliminate the sand etc. periodically.7) A sand-strainer was equipped between the press-juice tank and the sending pump.8) After a regular fermentation was achieved, 30-70 minutes was needed per day to operate and control the plant. In addition to this labor, 255.5 hours was consumed to repair the plant in 2 years.