Patent ID: 8282889

Claim:
A decomposing system for polyisocyanate residues comprising: a decomposing tank for allowing polyisocyanate residues and high temperature and high pressure water to contact with each other, a water feed pipe, connected to the decomposing tank, for feeding the high temperature and high pressure water to the decomposing tank, a drum containing polyisocyanate residues, a residual feed pipe, one end thereof being connected to the drum containing polyisocyanate residues and the other end thereof being connected to the water feed pipe, for feeding the polyisocyanate residues to the decomposing tank together with the high temperature and high pressure water, a solvent filling unit for filling the solvent at a connecting portion of the residual feed pipe with the water feed pipe, and an opening and closing unit interposed in the residual feed pipe at an end thereof connecting with the water feed pipe, and a residual pressure-feed pump interposed in the residual feed pipe at a location thereof on an upstream side of the opening and closing unit, wherein a part of the residual feed pipe extending at least between the opening and closing unit and the residual pressure-feed pump serves as the connecting portion in which the solvent is filled, and the solvent filling unit comprises a solvent feed line connected to the residual feed pipe between the residual polyisocyanate drum and the residual pressure-feed pump, and a solvent drain pipe connected to the residual feed pipe between the residual pressure-feed pump and the opening and closing unit.