A privately held snack-food manufacturer in Ohio expected to increase production of potato chips by 20%, to about 72 million pounds a year. While more potato chips would mean more profits, it also would mean more oil-laden wastewater from washing the potatoes and the fryers used to cook them.
PROCESS: When operators clean the fryers used to make the chips and other snacks, oil mixes with the wash water. Wastewater from the cleaning is processed through a series of dissolved air floatation (DAF) systems, and then is fed into a bioreactor before being discharged into the municipal water-treatment system. (The potato-chip plant is in a small village and is one of the municipality’s largest water consumers, discharging an average of 180,000 gallons a day.) Sludge from the DAF system is dewatered by a sludge press and is hauled off site for use in animal feed.
PROBLEM: The DAF system is not equipped to handle the large amounts of oil already produced, let alone the additional load that will be added with increased production. Oil introduced to the DAF accumulates in an influent well and prevents adequate penetration of chemicals for water treatment, which reduces the effectiveness of the pretreatment of water before it enters the bioreactor. Additionally, oil removed in the DAF sludge causes blinding on the sludge press fiber cloths, causing ineffective dewatering of the sludge; and, oil entering the bioreactor causes more stress on that system. This results in longer treatment times.
AquaBlue Inc., water-treatment specialists working with the manufacturer, wanted to install a Model 6 V Brill™ oil-recovery system to reduce the amount the oil in its wastewater and improve the efficiency of its machinery. A challenge was that the plant’s 4-foot-diameter wastewater pool is in a cramped area crowded with pipes and other equipment. This limited the space available for adding new equipment.
Jim Petrucci, Oil Skimmer’s Vice President, said because the company uses factory-trained representatives, such specialization is possible. “You aren’t picking out something from a catalogue. We can adapt, modify, or even build from scratch.”
In a unique anti-clogging design, the Model 6V has a polyurethane tube that attracts and collects the waste oil as it floats on top of wastewater. The tube passes through a scraper system to remove the oil, which flows by gravity into a containment drum.
BENEFITS: Since it was installed, the Model 6-V has been removing about 2,000 gallons of oil a week from the wastewater system, bringing many benefits to company, including:
- Cost: The wastewater requires less treatment before it enters the municipal system, reducing the amount of energy, labor and chemicals needed. Also, hauling costs for sludge removed from the water have fallen 30% because the wastewater treatment produces less sludge, and the sludge cakes that are produced have a lower moisture content.
- Improved asset performance: The plant’s DAF system is working more efficiently. “The filter press performance has increased, requiring less operator time cleaning the press,” said the company’s wastewater treatment facilitator. Additionally, loading on bioreactors where the water is treated has been greatly reduced, improving efficiency.
- Decreased material waste: The manufacturer has found a market for the discarded oil in companies that make bio-fuels, thereby keeping about 8,000 gallons of discarded oil out of landfills each month. The underground tank to which the Model 6V discharges oil is pumped out once a week.
The snack-food company has been so pleased with the results of the Model V6 that it is considering adding two more machines to other parts of the plant.
“We would recommend that anyone experiencing oil issues consider an oil skimmer from Oil Skimmers Inc., the company’s wastewater treatment facilitator said. “For a relatively small investment, our operations have been improved dramatically.”
The Model 6V operates independently and, if needed, can run 24 hours a day, seven days a week. Its internal components are made of high-strength steel and bronze for durability. External parts are made from abrasive-resistant ceramic. The machine has a lifespan of more than 30 years.