Paraffin Wax Operation

INDUSTRY: Paraffin Wax Manufacturing and Processing

APPLICATION: Stainless steel pans utilized in forming solid blocks of paraffin wax

PROBLEM:

A major manufacturer and processor of paraffin wax was experiencing release problems on his conveyor lines in the processing of paraffin. Hot liquid paraffin being poured into stainless steel pans and conveyorized into chilling rooms for cooling were sticking to the pans rather than releasing after exiting the chilling rooms. Hammers were used to beat on the bottoms of the pans by operators. Coatings from other suppliers were applied including silicone and other bakery-type release coatings, but failed to solve this problem.

SOLUTION: Impreglon 870 Coating

Impreglon 870 coating was applied to the inside surfaces and outside edges of the pans. Coatings from other coating companies were also applied for comparative testing. After four to six weeks all the competitors’ coatings were beginning to fail. The Impreglon 870 coating continued to provide the necessary release. The test ran for two years with no apparent sticking or removal of the Impreglon coating.

CONCLUSION:

The customer specified the Impreglon 870 coating be applied to all paraffin pans. The total number of pans exceeded 4,000. They were coated in batches of 150-200 at a time. To date, more than 3,000 pans have been processed.

INDUSTRY: Chemical Processing

APPLICATION: Chemical Drip Pans & Piping

PROBLEM:

A major chemical processing plant was having problems with its chemical drip pans and steel piping. The plant is involved in the manufacturing of a variety of petroleum products.

One such product produced by reacting petroleum distillates with oleum, an extremely corrosive solution of free sulfur trioxide (SO3)in anhydrous concentrated sulfuric acid (H2SO4).

The spent acid from the sulfonation process was a heavy oily liquid containing up to 95% anhydrous H2SO4 and was corroding away the piping and chemical drip pans used in transferring the acid to storage tanks.

Of particular concern were the problems that developed when the leaks started developing around the flanges and sulfuric acid began to drip. Although made from high performance alloys, the acid was attacking the alloy after being in service for less than one year. Not only from the standpoint of safety, but also the environmental impact, this was unacceptable.

SOLUTION: Impreglon 216

The solution to the problem came when Southwest Impreglon, Inc. recommended the application of its Impreglon 216 coating. The coating was applied to all the internal wetted surface areas of the piping and chemical drip pans. The coating was applied (20-30) mils thick and holiday spark tested @ 5000 volts D.C. to certify that there was no pinhole porosity in the coating. Both the coated piping and drip pans were installed and put back into service.

CONCLUSION:

Eliminates Drip Pan Problems

Both the piping and drip pans were inspected one year later at the regularly scheduled maintenance. Neither the piping or the drip pans showed any signs of corrosion. As of this date, and almost 2 years later, the equipment is stillin service with little or no signs of corrosion. Since that time, the customer has specified for all the drip pans and associated piping to be coated with Impreglon 216.

INDUSTRY: Chemical Processing

APPLICATION: Venturi Inlet

PROBLEM:

A major chemical processing plant was experiencing problems with its venturi inlets. The venturies were part of an exhaust duct system used in the removal of chlorine from a gaseous stream. The venturies measured approximately 8? in diameter and about 3? tall.

Although the venturies were made of stainless steel, they only lasted about 8 months in service. Chlorine gas would react with moisture in the air to produce hydrochloric and hypochlorous acids which would attack and corrode the venturies.

Other alternative materials of construction were considered, including fiberglass. However fiberglass had also previously been used and was found to have its own problems. The fiberglass would begin to deteriorate and begin leaking. There was also the concern as to the material being too fragile and expensive to maintain.

SOLUTION: Impreglon 216

The solution to the problem came when Southwest Impreglon engineers recommended the application of their Impreglon 216 coating. The coating was applied (20-30) mils thick to all the internal wetted surface areas of the venturi and then holiday spark-tested @ 5,000 volts D.C. The coated venturi was then placed into service.

CONCLUSION:

Coated Venturi Inlet Finds New Life

The coated venturi has been in continual service since installation with the exception of inspections during regularly scheduled maintenance shut-downs. Since the initial installation date, and almost 2 1/2 years later, the venturi is still in service and performing trouble free.

INDUSTRY: Chemical Processing

APPLICATION: Filter Housing

PROBLEM:

A major chemical processing plant was experiencing problems with its filter housings and associated piping used in the manufacturing of zirconium.

In one of the process steps for the manufacturing of zirconium, they were combining sodium hydroxide with chlorine to produce sodium hypochlorite. Filtering systems were being used to remove chlorine from the gaseous stream generated during production. The chlorine gas would react with the moisture in the air to produce hydrochloric and hypochlorous acids that eventually corroded the steel pipe and filter housing beyond the point of structural integrity.

Yearly scheduled maintenance shut-downs required the removal and replacement of corroded chlorine piping sections as well as filter housings.

Maintenance engineers knew the trade off…specifying low cost mild steel as the material of construction would require yearly replacement and the constant battle with corrosion throughout the equipment’s useful life. And while stainless steel and other premium metals were found to be more corrosion resistant, they were prohibitively expensive. Even highly corrosion resistant liners were found to be inappropriate, fragile, or difficult to maintain.

SOLUTION: Impreglon 216

The solution to the problem came when Southwest Impreglon engineers recommended the application of their Impreglon 216 coating. A test section of approximately 50? of steel pipe and 1-filter housing vessel were internally coated with (30-40) mils thick of the Impreglon 216 coating. The coated test section was then installed and put back into service.

CONCLUSION:

Coated Filter Housing Survives Acid Test

The test section of Southwest Impreglon coated pipe and filter housing were inspected after 6 months of service with no evidence of corrosion. The coating was subsequently inspected after 12 months, 18 months, and 24 months of service, and still no evidence of corrosion. From the initial date of installation and almost 4 yeras later, the equipment is still in service with little or no signs of corrosion.

INDUSTRY: Pigment Processing Plant

APPLICATION: Stainless Steel Blowers Utilized in Conveying Hydrochloric Acid Fumes

PROBLEM:

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.

CONCLUSION:

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.