How is Sludge Conditioned in Internal Treatment?
There are two general approaches to conditioning sludge inside a boiler: by coagulation or dispersion. When the total amount of sludge is great (as the result of high feed-water hardness) it is practical to coagulate the sludge to form large flocculent particles. Thes flow readily with the boiler water and can be removed by blow-down. This can be accomplished by careful adjustment of the amounts of alkalis, phosphates and organics used for treatment, based on the fee-water analysis. When the amount of sludge is not great (low hardness feed-waters) it is more practical to use a higher percentage of phosphates in the treatment. Phosphates form finely divided sludge particles. A higher percentage of organic sludge dispersants is used in the treatment to keep the sludge particles dispersed throughout the boiler water.
