To inhibit the scale deposition on the inner wall of a slurry pipeline due to separation, at a high-temp. section, of an alkaline earth metal salt contained in a waste as effectively as possible to thereby enable the continuous operation of a waste treatment system.
A waste contg. org. solids is crushed to give a slurry having a water phase. An alkaline substance is added to the slurry, which is then subjected to hydrothermal reaction. In elevating the temp. of the slurry before the reaction by passing it through heat exchangers 16 and 18, an acidic substance is added intermittently to the slurry on the upstream side of the heat exchangers so that the product resulting from the reaction has a weakly acidic pH. Then, the reaction is conducted in a reactor 14 and the resultant slurry is cooled and dehydrated. thus giving a fuel.
OMIYA YOSHIHIRO
HIGO TSUTOMU
SERIKAWA ROBERUTO MASAHIRO
EBARA CORP
Next Patent: WASTE TREATMENT METHOD