Pulp & Paper I

August 30, 1994

It was in 1994 that Sales Representative Gary Gann came to us with a chance to test in a paper mill. His customer, a major recycle paper mill, had a severe problem because their primary and secondary sewage treatment plants were no longer able to carry the load. Would we be able to filter the waste stream?

Despite four decades of pressing, Vincent had never had equipment in a pulp mill. Sensing a unique opportunity, we responded by dispatching two small presses for trials. By the time these presses made it back to Tampa they had been modified many times. It took that to meet the challenge.

Engineering Management at the plant hoped that a screw press would be able to remove solids from their waste stream. They wanted to avoid adding another belt press because of the high maintenance expense and need for an operator. It turned out that three other screw press manufacturers had tried their equipment at the plant, without success.

We learned from their experience. Blinding on ash and clay was avoided by going to a profile bar (heavy wedgewire) screen. A purging problem was solved by improving the arrangement of the auto- adjusting discharge cone. Press plugging was avoided with a combination of the interrupted screw flight design along with a unique by-pass and dilution system. It took several modifications to our standard citrus screw press to make it work.

Today the plant is avoiding pollution problems. They used one of our larger rental press until a pair of all-stainless VP-16's could be delivered. In fact, they were able to shut down one of their two waste digesters.

The application was challenging because of the very wide range of conditions that exist. The plant produces boxboard by recycling pre-consumer waste paper, so screen rejects from a variety of stages reach the press. When metal is detected, thick stock is diverted to the press. Periodically their clarifier backwashes fine sludge to the press. Other times the inflow becomes extremely dilute because flushing is going on in the plant. Our one press is handling this full range of materials!

5/97 Update: Today Pulp & Paper is more than half our business!

Issue 13