Fundamental management

June 1, 2007
FOUNDING father Ben Franklin had it right when he said an ounce of prevention is worth a pound of cure and three speakers endorsed that sentiment while

FOUNDING father Ben Franklin had it right when he said an ounce of prevention is worth a pound of cure — and three speakers endorsed that sentiment while discussing tank wash equipment at the National Tank Truck Carriers Tank Cleaning and Environmental Council Seminar April 2-3 in New Orleans, Louisiana.

Bill Miller of M T Clean LLC, Bob Delaney of Gamajet Cleaning Systems Inc, and Van Dalton of Pump Systems Inc contributed their expertise to the various topics, emphasizing the importance of understanding preventive maintenance and the capabilities of boilers, spinners, and pumps.

“Boilers are the heartbeat of a tank wash,” said Miller. “They are a vital link that generates the energy needed to facilitate cleaning procedures.”

In discussing boiler treatment, he pointed out that a heated feed tank that also is utilized as a condensate return is the best place to input the proper chemicals. The condensate return is important because it preheats the boiler feed water, eliminating thermal impact, and the condensate water has already been treated once, which lowers chemical usage.

“As the boiler calls for water from the pre-heated feed tank, a pump should simultaneously inject the proper amount of chemical needed,” Miller said. “Internal treatment chemicals should include scale and corrosion inhibitors, oxygen scavenger, and water softener.”

Daily monitoring and annual inspections also are essential elements for maintaining efficient and long term boiler operations. Well-trained personnel who conduct complete and inspections are paramount, Miller added.

To meet environmental requirements, he suggested that low-NOx boilers would be a wise choice when considering new installations or boiler replacements.

Miller also addressed boiler storage for equipment that is not in operation. Idle boilers are vulnerable to corrosion when air (21% oxygen) contacts moist metal surfaces. To control corrosion, the metal must be protected by keeping surfaces completely dry or by excluding all air by filling the boiler with properly treated water. Before storage, boilers should be properly prepared. During storage they should be inspected regularly, the intervals based on whether they are wet- or dry-stored.

Spinner capabilities

Turning to spinners, Delaney pointed out that tank cleaning facilities should use good preventive maintenance and appropriate equipment for their spinners to avoid damage and downtime. Wash managers should understand the capabilities of the equipment and apply them accordingly.

He pointed out that in sealed systems the oil-lubricated machines have a sealed gearbox and should be filled with Federal Drug Administration-approved oil. Any heavy-duty gear oil, high or low temperature lubricant, or grease can be used, however. The sealed gearbox prevents contact between the lubricant and cleaning solution, but extreme temperatures do reduce lubricant viscosity.

In a flo-thru system, the gearbox is lubricated by the cleaning solution, which means direct exposure to fluid. Hot liquid is a poor coolant and when it comes in contact with the gears, which are generating their own heat, the liquid can flash to vapor. In addition, clearances tighten for the moving components, he said. The systems were not created for tank sanitizing procedures, so, when they are used in that way, there is a higher frequency of failure and higher maintenance cost.

He also noted hot water can flash to vapor in the low-pressure area between the stator and the rotor. In this case, the overall rpm of the machine is reduced. Another performance hitch may occur when facilities are located at elevations significantly above sea level. In these locations, the boiling temperature of the liquid will be lower and this will further influence the machine's function. Yet another problem may arise when the hot water exits the unit. If the liquid is hot enough it will flash to a vapor, then condense back to a liquid as it cools. This will disrupt the cohesiveness of the jet and cause impact reduction.

Pumps are other pieces of equipment vital to the wash rack's efficiency that benefit from preventive maintenance in order to offset downtime. Dalton said that although they may be expensive, pump protectors are worth the cost. “Think of them as insurance,” he said.

Protectors measure horsepower and as the flow rate rises along with the horsepower, an alarm is sounded before the pump is damaged by the load. It will also detect dry running and/or loss of flow. Another type of protector responds by measuring amps. However, it measures on the high side of the pump curve, which may not be as effective.

Protectors can be purchased with new pumps or as additions for pumps already in place. Prices range from $400 to $700, but Dalton added that the expense can be offset because the protector could eliminate the cost of one seal repair.