Cleaning up

Sept. 1, 2006
DEMAND for transportation of sweeteners and other foodgrade products grew steadily in recent years, and Transport Service Company has worked hard to keep up with customer needs.

DEMAND for transportation of sweeteners and other foodgrade products has grown in recent years, and Transport Service Company has worked hard to meet and exceed customer needs. One recent step taken was an upgrade of the carrier’s four-bay wash rack in Loudon, Tennessee.

Changes include a third vat-style stainless steel foodgrade cleaning unit that was installed to boost productivity.

“The additional wash unit made it possible for us to double production on each of our two shifts,” says Mike Weaver, Loudon terminal manager. “We are now cleaning up to 22 trailers per shift, and we have the capacity to add a third shift to meet increased demand.”

One of four foodgrade wash racks in the Transport Service terminal network, the four-bay Loudon facility is dedicated to sweetener trailers. Seven of the tank truck carrier’s 12 terminals handle foodgrade shipments. In addition to sweeteners, liquid edibles cargoes include glycerin, juices, molasses, sorbitol, vegetable oils, and beverage alcohol.

Transport Service has been hauling liquid and dry bulk food cargoes since 1967, and that part of the business accounts for about 40% of the tank truck carrier’s revenue. The foodgrade operation runs 300 tractors and 400 tank trailers.

The Transport Service wash racks help ensure that the trailers are clean and ready for each new load both internally and externally. Transport Service believes washing the outside of the vehicle is an integral part of the cleaning process. Every effort is made to ensure that the facilities can keep pace with the growth in the foodgrade business, and that was a key factor in the decision to upgrade the Loudon operation.

Prior to the upgrade, the wash rack had two stainless steel Sani-Matic vat-style systems, each shared by two cleaning bays. While four trailers at a time could be accommodated in the rack, only two could be cleaned. Replacement of the third unit makes it possible to clean three trailers at a time now.

Each Sani-Matic unit has two 750-gallon tanks for wash water and sanitizer, both maintained at 190°F. Steam is supplied by two 100-horsepower boilers.

Detergent is not used in cleaning sweetener trailers. The three-stage cycle of pre-rinse, wash, and sanitization relies on cold and hot water. The sanitizing stage is maintained at 190°F for 15 minutes. Cleaning data is tracked on a chart recorder.

Filter system

Fresh water entering the wash system passes through a 150-micron mesh filter. Another 150-micron mesh filter is on the supply line that is within 10 feet of the spinner. A third filter treats the wash water returning to the Sani-Matic tank.

“The filters are important, and we don’t believe we can have too many,” Weaver says. “Our obligation to our customers is to provide absolutely clean and sanitized tanks. In most cases, we go well past our customers’ requirements.”

The filters are checked twice a week for contaminants by wash rack workers. A Lightning MVP unit also is used by the wash rack supervisor to check for microbial residue in the stainless steel Sani-Matic tanks. v“The test device measures adenosine triphosphate in the wash tanks,” says Dave Marikos, Transport Service Company Foodgrade Division vice-president of sales and marketing. “Tank trailers also are swabbed with the Lightning MVP device on a random basis for quality assurance. We keep all of the swab reports on file for a year.”

Pumps rated at 20 horsepower send cleaning water to Tankmaster spinners operating inside the trailers. Spinner output ranges from 60 to 200 psi, depending on the water pressure from the city system. An in-house-designed Y-fitting makes it possible to clean the cargo tank and the rear-mounted product pump simultaneously.

“In addition to efficiency, the Y-fitting helps ensure that we capture all discharged water during the cleaning process,” Weaver says. “This is essentially a closed-loop system. We store wastewater in a 4,500-gallon tank and release the water into the sewer after pH is adjusted and contaminants are removed.”

Once trailers are cleaned, our tank cleaners seal all tank access points. This is part of a wide-ranging seal program that Transport Service implemented several years ago. The program mandates that trailers be sealed at all times for security.

Tanks are resealed after being loaded by shippers, and drivers reseal the empty tank after the cargo is delivered. Every seal change is documented on a log in the pump box at the rear of the trailer. When a trailer arrives at the wash rack, tank cleaners verify all seal numbers before tank cleaning begins.

Marikos stresses the importance of good hiring and training programs at Transport Service to ensure that the tank cleaning and security operations function properly at all times. “We don’t want to leave anything to chance,” he says. “We want to have the best people available on the job. They are key to a good foodgrade cleaning and sanitizing operation, and we believe we have some of the best tank cleaners in the industry.”

New hires spend at least a month in training, learning proper procedures on inspection, tank cleaning, swabbing, and seal security. At the conclusion of the training, they have to pass a test before being certified to work on the rack.

Good training combined with good equipment helps ensure that the Transport Service foodgrade trailers meet customer expectations for cleanliness and security.

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