CHEMICAL CLEANING METHOD OF HEAT TRANSFER TUBE OF WASTE HEAT RECOVERY BOILER

摘要

PROBLEM TO BE SOLVED: To efficiently clean the inner surface of heat transfer tubes of a waste heat recovery boiler with least energy by allowing heated cleaning water to flow into the inside of the heat transfer tubes under a condition that a waste gas supply inlet and a waste gas outlet of the waste heat recovery boiler are closed. ;SOLUTION: In a water heat recovery boiler 1, from the upstream side, heat transfer tubes 2 which are made of a high pressure superheater/regenerator, a high pressure evaporator, a denitriding device, a high pressure economizer/evaporator, a medium pressure economizer/evaporator, a high pressure economizer and a low pressure economizer/evaporator are vertically disposed. A waste gas supply inlet 3 and a waste gas outlet 4 are provided with temporary lids 5 and these lids 5 closes the waste gas supply inlet 3 and the waste gas outlet 4 to shut off the inflow and flow out of outside air. Under this condition, cleaning water heated to 80-90°C is fed to the heat transfer tubes 2 through a cleaning water supply inlet 6 and is discharged from a cleaning water outlet 7. Due to such a construction, the flow of outside air caused by the heat dissipation from the heat transfer tubes 2 becomes small so that the heat loss can be reduced and the temperature of cleaning water is held at a suitable temperature thus enhancing the cleaning efficiency.;COPYRIGHT: (C)1999,JPO