Boiler chemical cleaning steps and matters needing attention
1, the water leak detection:
hydraulic leak detection is to use the pump will be filled with water in the system, whether there is funnelled inspection system, such as system in good condition can be ready for the next step work.
2, chemical cleaning:
will be cleaner and water ratio, to use the concentration ( The provisions of the state is less than 10%) And then pumping liquid into the circulation system, and constantly emptying guide tube, lest produce gas resistance, constantly supply cleaning fluid, until outlet exhaust cleaning solution, and then continue to pump circulation, cleaning time is 10 ~ 20 hours ( According to the condition of reaction to extend or shorten the reaction time) 。
3, water cleaning:
water rinse rinse clean the residue cleaning fluid to the system, in order to avoid the system of local corrosion, PH test paper test outlet in neutral.
passivation reaction is to make the cleaning after activation of the surface of the metal layer of passivation film, avoid contact with the oxygen or the free oxygen in the water oxidation reaction. Passivation agent with the ratio of water to use concentration ( Concentration of 3%) , then pump into the circulation system. After being passivator is full system for circulation, the reaction time is 10 ~ 24 hours, and then discharge passivation solution and prepare to water flushing.
5, water washing,
the rinse water is to the passivation solution that remains is rinsed clean, make the system be decomposed in stripping of dirt with water, and test the PH value is neutral, namely clean finish.
choose the chemical cleaning cleaning pump, the box: for boiler water wall scale amount is larger, so the cleaning pump needs to choose traffic older, at least to ensure water wall cleaning velocity at 0. About 2 m/s, cleaning tank is bigger, as far as possible let more temporary system for acid pickling, make cleaning process has a bigger cushion.
on temporary systems: down in the process, must be carefully check each joint, to ensure that no hidden dangers. Because hydrogen fluoride are necessary for ammonia acid pickling process, so the joint rigor and higher corrosion resistance than pure hydrochloric acid pickling requirements.
water wash: water wall system after pickling, turn off hydrogen vacuum discharge door, when the water to be filled with water on the door again after sacking hydrogen, and then maintain continuous flushing liquid level. So than PaiSuan, direct edge of the water discharge method province water time, and compared directly to maintain hydrogen door always open to discharge are less prone to rust, also can fully guarantee flushing effect.
passivation liquid emissions: stop pump discharge, maintain high steam drum water level, the first opened the door of economizer recirculation, accident of steam drum water door, row, row, and in the heating furnace into, hydrophobic discharge door, discharge after a certain time, economizer and water wall again within the passivation solution. So it can ensure the valve with pressure flushing, door core is not easy to peeling off in the process of pickling corrosion products.