Case Study

Centrifugal Pumps Boost Efficiency for Juice Processor

Source: Tri-Clover Inc.
Tri-Clover Inc.ington Frontier Juice has gone from crushing 100 tons of apples a day in 1990 to a current schedule of 400 tons of apples a day. And with the installation of an ultra-filtration process in their Prosser, WA plant, the company has been able to achieve an impressive clarity of rating of 99.8% on significant quantities of apple juice.

"Our juice has a reputation as being among the industry's purest," claims Washington Frontier plant manager Bart Hoopman. "We can make a light colored juice because our process is so streamlined. Overall production is completed in a day from fruit crushing to finished juice storage. The plant turns out a very stable product."

Also contributing to product clarity, consistency and volume are five <%=company%> CL Series centrifugal pumps, which have helped boost production efficiency and reduce operating expenses. Installed in the fall of 1996, the pumps have performed a variety of tasks in Washington Frontier's operation, all the while maintaining a pattern of reliable operation without downtime.Tri-Clover Inc.ington Frontier Juice processes cherries, plums, strawberries, watermelons, apricots, pears, peaches and Nigra grapes, in addition to apple juice. The Tri-Clover pumps have been able to handle the variety without difficulty. Plus, the pumps' shared design and use of the same seals keeps spare parts inventory to a minimum while reducing service time.

At Frontier's Prosser plant, juice goes from a 6000 gallon feed tank to two 50 HP CL pumps, which pump product across a PCI ultra-filtration membrane (filtering to a 200 molecular weight) over a 20 hour period at a rate of 440 gpm.

Two 50 horsepower CL pumps

Another 10 HP CL pump serves as a permeate pump, removing the product from the membrane system at rates of up to 120 gpm and then passing the juice through product chillers and on to the evaporation process.

10 horsepower CL pump

Processing temperatures vary. Apple and pear juice reaches approximately 130°F. To preserve the desired juice color and flavor, strawberry and cherry processing temperatures reach just 70°F.

The two other CL pumps used in the operation circulate water for heating and provide mixing for chemical injection during the cleaning cycle. Every 20 hours, the plant performs a CIP (clean-in-place) operation on the processing system, which involves a caustic solution, followed by chlorine and a nitric acid solution at temperatures below 140°F.

Design and technical assistance on the ultra-filtration system was provided by Tri-Clover's Washington-based distributor, Pro Sales Inc. John Poe, a principal of the distributorship, noted that close collaboration and teamwork involving the two organizations helped to get the system installed within a tight time frame.

Tri-Clover's precisely engineered tolerances between the impeller and front cover contribute to higher pump efficiencies. An advanced impeller design reduces entrapment and air lock for reduced cavitation and lower NPSH (Net Positive Suction Head).

Hoopman noted the pumps have exceeded expectations on the ultra filtration unit, from the standpoints of production efficiency and reliability. Economy, too, is a factor. The company has been able to reduce downtime, as well as inventory.

Seal reliability is a big contributor to the latter. When Washington Frontier ordered the pumps, they wanted all pumps to use common seal parts to reduce storeroom inventory. The CL Series pumps' general-purpose carbide seals can handle all of the juices Washington sends through the line.

Common seals reduce inventory..

The CL pumps' easy access to the seals enables rapid replacement when needed. Lost time and its impact on direct and indirect costs were issues with the previous pumps used by Washington Frontier. Those pumps required two hours to change seals. Now the task can be performed in 15 minutes.

"On seal changes for the former pumps, we would use about $40 of a mechanic's time and spend nearly $140 on a new seal kit.

"An even bigger expense was that of line downtime. Repairing the pump meant taking down the line. In a 65-person plant we would have 10 people idle until the pump was back in service.

"Now when the day comes to change seals on the CL pumps, we can do the job when production workers are on their break," Hoopman said.

By Pam Ahlberg

For more information: Tri-Clover Inc., 9201 Wilmot Rd., Kenosha, WI 53141. Tel: (262) 694-5511; Fax: (262) 694-7104.