Ethylenediaminetetraacetic acid (EDTA) has a proven record of aiding in the protection of water treatment pipes and equipment. Bell Chem, the water treatment chemical supplier you can trust in Central Florida, carries this HEDP for its ability to effectively sequester metals within pipes.
Deposition is a fact of life for water treatment plants. Water purity determines the likelihood of deposits left within the boilers and other portions of the feed lines. When feedwater contains even the slightest amount of impurity, the possibility of buildup along any metal surface is almost guaranteed.
Contaminants common in feedwater include metals (magnesium, copper, iron, aluminum), nonmetals (calcium and silica), silt, and oil. These categories are identified as either scale or sludge. Scale is formed by salt crystals that adhere to surfaces while sludge precipitates outside the water treatment system and is transported to the metal surface of the treatment system by means of incoming water.
Scale formations are soluble until they concentrate due to the high heat transfer rates that drive evaporation. Because the crystalline structure of scale is homogeneous, different areas of scale may have completely different chemical compositions and require varied methods of removal. Both metals (magnesium, aluminum, and iron) and nonmetals (calcium, silica, and occasionally sodium) can create scale. Scale forms extremely slowly, which causes the buildup to be hard, dense, and well defined, giving scale the ability to withstand most mechanical and chemical cleaning.
Sludge deposits may also prove to be dense, hard, and difficult to remove, especially after exposure to extreme heat levels, which bakes the sludge onto the surface of the water treatment equipment. Baked sludge is similar to scale in its tenaciousness.
Once either sludge or scale forms inside a facility, the chemical contaminants attract like chemicals. This results in larger and larger patches of affected metal. These accumulations inside pipes can significantly increase water pressure because the diameter of the pipes diminishes, causing overheating and, especially with salts, corrosion. Removing scale and sludge results in facility downtime.