Refinishing saves tank time and money; Publix uses mechanical polisher to restore tank finish - Publix Super Markets Inc - Applied Technology

Dairy Foods, June, 1989 by Rick Lingle

Refinishing saves tank, time and money

You may not have heard of Publix, the 9th largest supermarket chain with 361 stores solely within the state of Florida.

The multi-plant Publix Industrial Center in Lakeland, Fla. includes a dairy processing plant that employs 220 and can make 70 tons of ice, 150,000 gallons of milk, and 28,000 gallons of ice cream a day. The plant also produces soft drinks, bottled water, cottage cheese, sour cream and yogurt.

Publix conducts ongoing tours of the dairy plant as part of its public relations program.

Publix uses six 30,000 gallon milk storage silos. Inside one of the tanks, Publix found something amiss: a routine quality control check had turned up a dull finish.

On closer inspection, milk and ice cream processing chief engineer Joe White found that the 8 1/2-year-old tank was showing signs of chemical burn and film buildup. The culprit--subsurface pitting, most probably due to wear and tear after several thousand washdown and sanitation cycles.

One of Publix's options was to replace the tank. However, that would cost about $45,000, not to mention an extended plant shutdown and the headaches involved with renting a crane to put the tank in place. A second option, to hand-polish the tank, was prohibitively expensive and time-consuming.

Fortunately, Publix had a third alternative, refinishing the stainless steel tank using a mechanical polisher, from Springfield, Missouri-based Stainless Fabrication Incorporated (SFI). The mechanical polisher works as effectively as hand polishing in a fraction of the time and cost of manual methods.

Total cost: less than $6,000

After contacting SFI in July 1988, White was provided with several customer references, including one from Heritage Dairy in Nashville, Tenn. Heritage had one of its tanks repolished by SFI. After speaking with Heritage's plant manager, White was convinced that SFI could also help him. The total cost for the project: less than $6,000, only one-eighth the cost to replace a tank.

Soon, arrangements were made, with one major requirement: SFI had a 72-hour "window" in which to complete the work.

For safety's sake, SFI's team of two technicians took turns on two hour shifts inside the tank monitoring the mechanical polisher. The machine, which polishes any round, stainless steel silo, worked its way down the inner surface of the 12-foot diameter, 56-foot-tall tank, polishing the surface to a #4 finish to meet 3A requirements.

According to SFI, the steps needed to bring a tank back to 3A standards is determined by the depth of the pitting or corrosion. Light damage can be taken care of in one step while heavier damage may take several. About 95% of the work is done by the mechanical polisher; the remainder, such as polishing around manways, is done by hand.

After completing the task in only 48 hours, SFI personnel sought the approval of White. "I like the fact that SFI wanted me to be satisfied before they left," says White.

`A factory finish in the field'

Was he satisfied with the results?

"The SFI method gives a factory finish in the field," reports White. "Publix buys on high quality, good service, and a fair price. With SFI, we got all three."

SFI specializes in stainless steel tanks for the dairy, food, and beverage industries. The company also can build tanks on-site, up to a capacity of 600,000 gallons. This capability eliminates any need to remove part of a roof as is typical of conventionally installed tanks.

Other services provided by SFI include: adding agitation or other component systems; repairing or replacing damaged tops; or increasing the capacity of existing tanks.

The bottom line for Publix: "If this ever happens again to one of our tanks, we would automatically seek the services of SFI," says White. "SFI would be the first people we'd call."

PHOTO : The refinishing option arranged by milk and ice cream processing chief engineer Joe White saved Publix $39,000.

PHOTO : An upward view of the mechanically polished interior of the 12-foot diameter, 56-foot-tall milk storage silo.