INDUSTRY: Pigment Processing Plant
APPLICATION: Stainless Steel Blowers Utilized in Conveying Hydrochloric Acid Fumes
A major pigment processing plant was experiencing severe corrosion problems with its blower wheels. Blower wheels ranging in size from 22-48 inches in diameter and made of Type 316 stainless steel were used to remove hydrochloric acid fumes generated in the manufacturing steps. Because of corrosion, the blower wheels became problematic after only one to two months of use and had to be removed by maintenance personnel.
In addition to the corrosion problems, maintenance personnel found themselves wire brushing and cleaning away corrosion between shifts to eliminate possible contamination problems downstream. Because the wire brushing and cleaning attempts were not standardized and the blower wheels were spinning at a high RPM, a secondary problem of blower wheels becoming unbalanced was created.
SOLUTION: Impreglon ECTFE Coating
The solution to this problem was within the Impreglon ECTFE coating. ECTFE powder coating was applied 20-30 mils thick to all surfaces of the blower wheels. Spin balance checks on the wheels revealed that the coating could not be applied uniformly enough so as not to disrupt the blower wheels’ balance. Southwest Impreglon engineers developed a method so that solid ECTFE shapes could be cut to the exact weight needed to balance the wheels; they plastic welded them in the exact locations on the coated wheels to complete the balancing. The blower wheels were then spark tested for porosity at 5,000 volts DC as a final QC measure.
Almost two and a half years later, the wheels are still performing maintenance and trouble free.
The customer has specified that Impreglon’s ECTFE coating be applied to all their blower wheels in service (including those designated as spares). In addition to the blower wheels, other related process components, including piping, tanks, valves, ducts, and pumps have also been coated to solve their corrosion problems.