Patent ID: 7736440

Claim:
A solid product removal method for removing a solid product adhering to an inner face of a gas exhaust pipe member, characterized in that the method comprises the steps of: rinsing off a primary solid product formed upon reaction of an ingredient contained in exhaust gas with a moisture present in the gas exhaust pipe member and adhering to the inner face of the gas exhaust pipe member by feeding a primary rinsing water to the primary solid product; and rinsing off a secondary solid product formed newly upon reaction with the primary rinsing water and adhering to the inner face of the gas exhaust pipe member at an upstream side from the position at which the primary rinsing water is fed by feeding a secondary rinsing water to the secondary solid product in the gas exhaust pipe member, wherein the gas exhaust pipe member is provided with a first rinsing water supply inlet and a second rinsing water supply inlet; wherein said first and second water supply inlets are spaced apart at a given interval along a direction of flow of exhaust gas; the primary rinsing water is fed from the first rinsing water supply inlet; the secondary rinsing water is fed from the second rinsing water supply inlet, the second rinsing water supply inlet is disposed at the upper position than the first rinsing water supply inlet, and the secondary rinsing water is fed at a longer periodical interval than the primary rinsing water.