Separating wood chips from tar poses difficulties but this was not the only problem. The company also had to do it in a hurry, and dispose of the tar and chips in an environmentally correct way.

The problem resulted from an obsolete production facility on a site needed for a projected baseball stadium. Two huge water-sealed, telescoping tanks on the site had to be removed first—together with their 200,000 gallons (757,000 liters) of coal tar and 50,000 gallons (189,000 liters) of contaminated water.

First, the water was drained, purified, and released to a stream. While workers dismantled an old steel tank's wooden roof bracing, pieces of the old beams broke, dropped into the tar, and became splinters or chips as bulldozer's treads ground the wood as the bulldozer pushed the tar into a collecting pit. The company could no longer sell the tar to anyone for fuel or road use because the chips would plug burner nozzles or construction machine nozzles. Dumping would have been inappropriate not to mention the prohibitive transport and dumping costs. Time was running out for offering the cleared site to a municipality.

The company's project engineer decided on a Kason VIBROSCREEN Circular Screen Separator. Kason shipped the unit very quickly to help the company meet its deadline. Injected steam in the tar/chip mixture allowed for pumping it from the pit to the center of the separator's screen.

After passing through a 60 in. (1530 mm) diameter 30 mesh market grade screen, the tar exited through the spout. Once through the separator, the tar was fed to a storage tank for shipment to a local steam generating facility as fuel.

The chips moved across the vibrating screen surface and fell into 55-gallon (208 liter) steel drums that workers placed under the separator's solids exit spout. Trucks transported 90 drums of chips to an incinerator for disposal. Since the separation and transportation took place within 30 days, the site was cleared and sold to the city on time.

"Without this separator, we'd have been unable to get rid of the tar at a reasonable cost, in an environmentally sound manner," the engineer reported. "It sure saved us a lot of grief, and I will highly recommend this unit to any…company that has a similar condition," he added.

Screen Tips - Volume 10, Number 1 Spring 1995

Removing Wood Chips from Tar

When workers tried to remove wood beams from tank support structure, some of them fell into the tar, rendering it unusable for fuel or road use. Worse than this, the wood chips from the beams had to be separated from the tar before they could be properly disposed of.

Removing Wood Chips from Tar

A VIBROSCREEN Circular Screen Separator was brought in during a rainstorm to separate wood chips from tar after it was heated via steam injection.