How to prevent scale of biomass hot water stove
Biomass hot water stove chemical water treatment is a method to prevent the scaling of biomass steam boilers by adding an appropriate scale inhibitor to the water to make it chemically react with the hardness substances in the water to produce loose fluidized slag . The medicine adding treatment inside the tank has the advantages of less investment, simple equipment, convenient operation and convenient management, but its anti-scaling effect is not as good as the chemical treatment outside the tank. For horizontal oil-fired steam boilers, simple water treatment in the boiler is only suitable for vertical furnaces without water-cooled wall tubes. In addition, for sodium ion exchange treatment, when the residual hardness is large or the pot water pH and alkalinity cannot meet the standard requirements, the pot should also be added with medicine.
1. The main function of scale inhibitor
1. Reacts with hard materials to form water slag, remove sewage, and prevent fouling of biomass hot blast stove.
2. Maintain the alkalinity and ph of pot water.
3. A protective film is formed on the metal surface to prevent corrosion.
4. Promote the loosening and shedding of old sulfate and silicate scale.
2. Commonly used scale inhibitors
1. Sodium carbonate can be used alone, or it can often form a compound scale inhibitor with other agents.
2. Phosphate is often used as a calibrator to eliminate the residual hardness after chemical treatment alone outside the biomass hot water stove. It can also be used as a component of composite scale inhibitors. Generally, trisodium phosphate is commonly used. When the alkalinity of the feed water is high, disodium hydrogen phosphate or sodium dihydrogen phosphate can also be used to reduce the alkalinity.
3. Compound scale inhibitor, according to different water quality characteristics, according to the ratio to choose the appropriate composition.
4. Organic synthetic scale inhibitors such as organic phosphates and polycarboxylates have the advantages of low dosage and good scale inhibition, but the price is relatively high. At present, there are fewer waste products in biomass steam boilers.
3. Dosage of scale inhibitor: Determine the amount of scale inhibitor according to the test results. After adding the medicine, the ph value and alkalinity of the boiler water should reach the national standard. Since sodium carbonate is hydrolyzed at high temperature to form part of sodium hydroxide, scale inhibitors generally consist of sodium carbonate, trisodium phosphate and tannin extract. The dosage can be determined according to the difference between the total hardness and total alkalinity of the feed water of the biomass hot water hot air stove.