Innovative cleaning systems design and well-trained workers help keep productivity high at Prokleen Washing Services in Concord, Ontario, Canada. At its busiest, the eight-bay wash rack cleaned 118 tanks in a single day.
Typically, the wash rack cleans 75 to 80 tanks a day, and the mix can include tank trailers, tank containers, and intermediate bulk containers. The rack offers chemical and foodgrade cleaning, and the only products not accepted are hazardous wastes, PCBs, poisons, and pathogens. The facility operates around the clock.
"We built this wash rack to be as versatile as it is efficient," says Jeff Coles, Prokleen president. "This wash rack incorporates a lot of ideas I developed while working in other tank cleaning operations. We've combined proven cleaning technologies with the latest equipment and systems.
"We picked a good time to open a wash rack in the Toronto area, and our cleaning business has grown at a good pace. We're working with more US carriers involved in hauling chemicals between the United States and Canada. Toronto is also a destination for a lot of foodgrade shipments."
Business has been steady since Prokleen opened its doors in Concord, a suburb on the north side of Toronto. The 200,000-sq-ft wash rack cleaned its first tank trailer in December 1996 and was fully operational by March 1997.
It is next door to the headquarters terminal that was opened in 1996 by Concord Transportation Inc, a dry freight carrier, and Harmac Transportation Inc, a tank truck carrier. Al Wortzman established Concord in 1973 and partnered with Gord Pryce to start Harmac in 1983. Both companies were sold over the past year.
Owned by Wortzman and Pryce, Prokleen operates independently of the trucking companies and was not part of the sales. Coles says there are absolutely no plans at this time to sell the tank cleaning operation. Instead, the owners are looking for ways to make the wash rack even more successful.
While Harmac's own cleaning needs were a primary motivation for building the wash rack, Pryce and Wortzman determined from the outset that it would be a commercial facility. "Our first motivation was to build a wash rack to meet our own tank cleaning needs," Pryce says. "However, we were aware that there were no other commercial wash racks in the area, and we saw an opportunity to bring in outside business. Harmac cleaning accounts for less than 30% of the activity at the wash rack."
A wide range of services are offered, including an elaborate hose testing and maintenance program. Cargo heating is available, as well as fleet refueling and vehicle weighing services.
Chemical cleaning has brought the highest percentage of business to the wash rack, but foodgrade activity is growing. The foodgrade operation is kosher certified and has received approval by Coca-Cola, Cargill, and Archer Daniels Midland (ADM).
Chemicals include a preponderance of soap ingredients, resins, phenols, acids, caustics, and solvents. Ninety-five percent of the edibles are sweeteners, with chocolate and oils accounting for the remainder.
The wash rack started with four bays for chemicals and two for foodgrade. Two additional bays for foodgrade cleaning just came on line. A ninth bay is used for steaming, and the cleaning and wastewater treatment systems are in yet another bay.
Each cleaning bay is 120 feet long, providing ample room for two tank trailers at a time. Bays are 35 feet wide, which gives workers plenty of room to move around the vehicles that are being cleaned.
"Wide bays help improve efficiency, safety, and worker comfort," Coles says. "Workers are able to stay a lot dryer when the bays are wide, and they are less likely to bump into equipment."
Maximum overhead height is 28 feet from the floor to the eaves. The metal walls are set atop a two-foot-high concrete abutment that is intended to reduce the potential for corrosion along the lower edges of the walls.
The harsh Canadian winters were taken into account, and the building is heavily insulated. In addition, down-draft heaters over each doorway help prevent the formation of fog in the wash bays when the roll-up doors are raised. Fans rated at 60,000 cfm provide ample ventilation throughout the wash bays.
"We've installed scrubbers for aromatics, but we don't have vapor recovery in the wash bays," Coles says. "It's not required in Canada at this time. However, I'm sure it will be mandated at some time in the future. We've begun to take preparatory steps, such as adding vapor hoods to the spinner cones."
The floor received special attention. Chopped fiberglass was added to the cement to help prevent cracking, and the surface was given a diamond finish that is very hard and very resistant to chemicals. A 2% pitch helps ensure thorough drainage and prevents puddling.
The floor drains and sumps are lined with a membrane to minimize wear.
Coles and his management team designed the vat-style wash systems used in the facility. The chemical and foodgrade operations each have their own dedicated wash systems. The systems are automated but not computerized. "My experience has been that computer systems don't last in wash rack humidity," Coles says.
Each of the cleaning systems consists of a series of tanks: 1,000 gallons each for caustic and detergent and 18,000 gallons for fresh water. For chemical cleaning, Prokleen uses blended caustic with surfactants and wetting agents. The chemical detergent is Green Strip from Montgomery Manufacturing. Hot diesel is used as a presolve. The foodgrade system has foodgrade caustic and detergent.
Hot water and steam are supplied by a 300-horsepower boiler. Prokleen recently upgraded its steaming capabilities by adding an automated control system to the steam rack. "Better control helps prevent oversteaming, which can cause damage to gaskets and other components," Coles says. "We also added automatic blowdown capability so condensation doesn't freeze in the steam lines during cold weather."
In the wash bays, Prokleen specified Gamma Jet IV spinners that operate at 275 to 280 psi and have a flow rate of 80 gallons per minute. Smaller Gamma Jet V spinners are used when tank cleaning is done through the three-inch cleanouts.
Cleaning takes at least an hour for a trailer that has carried resins, while solvent tanks are done in about 30 minutes. It takes about 30 minutes in warm weather and 45 minutes in the winter to wash a sweetener tank.
Pumps send the cleaning solutions to the spinners in the wash bays, but the return is by gravity. "We get longer caustic life with gravity return," Coles says. "The churning and foaming caused by pumps shorten caustic life."
While cleaning solutions are returned to the vats for reuse, wastewater goes to either of two 24,000-gallon holding tanks. Solids are removed through a gravity separator, and the pH level is adjusted prior to the wastewater being discharged into the local sewer.
Control of wastewater quality is important, and it starts when a tank trailer arrives for cleaning. Prokleen workers check the tank for heel, and the wash rack accepts no more than five gallons. "Anything more and we call the customer to discuss disposal arrangements," Coles says. "Our aim is zero heel."
Tank fleet operators also are expected to provide an up-to-date material safety data sheet on the last cargo. US tank trailers arrive with the best documentation, according to Coles.
When documentation is inadequate, additional chemical details often can be obtained from a CD-ROM database developed by the Canadian Centre for Occupational Health and Safety. Annual updates are available for C$300 (approximately $200 US).
Good documentation is part of a strong safety program. Safety is stressed at all levels at Prokleen. Of particular note is the testing program for the hoses and fittings used in the tank cleaning operation.
Hoses and fittings are visually inspected and hydrostatically tested every 90 days. Wash rack maintenance personnel closely inspect the banding and fittings before putting a hose in the hydrostatic tank.
A hose will fail the inspection if the inspector finds damage to the banding or threads, if the coupling shows signs of movement or creeping, or if the couplings are out of round. Hoses also are rejected if they have been run over or if the casing shows signs of puncture, cracking, stretching, kinks, or bulges.
During the hydrostatic testing, the hose is locked into a fixture that was built in-house. The hose is filled with water, and all air is removed. Water pressure is raised to 10 psi, and the hose is inspected visually.
The next step is to boost the pressure to 1.5 times the manufacturer's rated pressure. The pressure must hold for five to 10 minutes while the inspector checks for leaks, bulges, and signs of coupling movement. Test data is recorded on a stainless steel band that is attached to the hose.
Safety is emphasized from the moment a wash rack worker is hired. On the job, they are required to wear steel-toed boots, coveralls, hardhats, rubber gloves, and safety glasses. The initial training includes instruction that is comparable to right-to-know programs in the United States and detailed instruction in confined-space-entry procedures. Dirty tanks are never entered. Even in clean tanks, Prokleen policies call for workers to wear supplied-air respirators.
"We try to limit the amount of tank entry," Coles says. "We perform interior inspections from outside the tanks using high-intensity lights. We do have to send workers into tanks to remove built-up product."
Only experienced wash rack workers are assigned to the most demanding tasks, such as tank entry and the actual cleaning of tank trailers. Those with less experience are assigned to activities such as cleaning hoses and valves.
Finding experienced wash rack workers was somewhat easier over the past year, according to Coles. A number of skilled wash rack workers became available when Provost Bulk Transport Inc ceased operations and closed its terminals and wash racks. Prokleen was able to hire several of the laid-off Provost employees with more than 20 years of tank cleaning experience.
With its skilled wash rack workers and sophisticated tank wash capabilities, Prokleen is well positioned to meet the growing cleaning needs of tank truck carriers.