To solve the problems of a means for increasing the quantity of air blown into a carbonization oven for sewage sludge or the like to lower the temperature in the oven, such as the problem of the increase in the quantity of the air blown into the oven and the problem of the increase in the costs of exhaust gas treatments, for example, dioxin countermeasures and deodorization measures, in the carbonization oven which needs the prevention of overheat.
This multi-stage screw conveyer type carbonization oven comprising a carbonization section which is manufactured by vertically disposing plural screw conveyers having nozzles for burning a carbonization gas in mantle portions penetrated in the horizontal direction in the heating oven and further disposing a heating burner for heating the screw conveyers and in which a raw material fed into the upper screw conveyer is carried, simultaneously pyrolyzed in a low oxygen atmosphere, and then discharged from the lower screw conveyer as the carbonization product, characterized by disposing one or more nozzles for spraying steam or water for cooling the oven to lower the temperature in the oven on the screw conveyer and/or between the screw conveyers.
HORII SHIGEKI
YAMAZAKI HIDEO
KURITA WATER IND LTD
OKAWARA MFG