Safety-Kleen

September 3, 1997

A 16" Vincent press that was originally sold to an Israeli citrus plant has ended up in Kentucky.  The new application is truly unique.

The press is used to separate combustible liquid from shredded hazardous waste.  Safety-Kleen, a national industrial waste disposal firm, operates a licensed facility that processes industrial wipe rags and liquid wastes.  The hazardous materials, mostly oils and paints, arrive on pallets, in drums, Gaylord containers, and pails.

The truckloads of waste, including the 55-gallon drums, pallets, and 5-gallon pails, are chemically analyzed and then rough shredded.  Most of the metal is removed with magnets.  Then the material is run through the Vincent screw press.

Since the waste includes fist-sized chunks of wood, plastic, glass and metal, the press had to be modified.  The screw flights were "pie cut" to enlarge the passages (although the Sterile configuration would have been a better bet).  The 3/32" citrus screen was changed to 1/2" thick plate with 3/4" perforations!  The drive was increased from 20 to 60 horsepower.  A reversing starter is used on the press so that it automatically reverses upon jamming, and then resumes forward operation.  Surprisingly, the machine runs a year between major overhauls.

The press processes about 15,000 pph (pounds per hour).  About 30% of the material comes out as press liquor.  This has a high BTU content and is sold as fuel for about $0.25 a gallon.  On the other hand, the press cake is a hazardous waste that must be incinerated, at a cost of about $0.30 a pound.  The scrap metal is sold separately.


Issue 66