Boiler cleaning agent used to select

A, pickling agent

On the different scale and metal material, should choose a pickling agent and the appropriate solvent, generally selected as follows:

1) for iron oxide scale, can add fluoride in hydrochloric acid or nitric acid cleaning;

2) for silicate scale, can add fluoride in hydrochloric acid (such as hydrofluoric acid, sodium fluoride, ammonium hydrogen fluoride) cleaning;

3) for sulfate scale or sulfate and silicate scale should be mixed, alkali cooking transformation, and then using hydrochloric acid or hydrochloric acid fluoride added cleaning;

4) for the carbonate scale, generally use hydrochloric acid cleaning;

5) when the scale sample containing copper, cleaning liquid should be added to prevent the copper plating additives. Generally use hydrochloric acid and thiourea and fluoride and other additives, or acid with ammonia and ammonium persulfate cleaning copper removal;

6) boiler with austenitic steel material, the prohibition of the use of hydrochloric acid cleaning, can generally choose EDTA, amino sulfonic acid, citric acid, formic acid, acetic acid, hydroxy acetic acid as the cleaning agent, and selecting the inhibitor and additives should not containing a halogen element.

Two, alkali Lotion

Alkali lotion used in the new boiler furnace, boiler pickling passivation in alkaline wash or scale transformation of the alkali cooking and small boilers, alkali cooking and cleaning, alkali lotion used commonly used are as follows:

1) operation of the boiler removing sulfate scale and silicate scale, the need for alkali boiling transition prior to pickling, alkali cooking liquid is generally composed of three sodium phosphate and sodium carbonate, sodium phosphate and sodium hydroxide or three and surface active agent.

2) the new boiler alkali or acid pickling alkali wash, alkali by sodium hydroxide and phosphoric acid three sodium, or three sodium phosphate and two sodium hydrogen phosphate and wetting agent. Boiler pressure boiler or austenite steel materials, sodium hydroxide alkali lotion should not be used.