Wet aluminum hydroxide sludge is a byproduct of our anodizing process. After drying, we dump the sludge in a bin from which it is eventually hauled away for disposal. To reduce the volume — and thus the hauling charges — we had been raking the material manually, but because the sludge is usually hot and frequently fuming, this was an unpleasant and laborious chore.
A few years ago we eliminated the human factor with an automated system that uses a DGO rodless pneumatic cylinder from Festo Corp., Hauppauge, N.Y., to power the rake. The 12-ftstroke cylinder mounts on a framework along the longer side of the rectangular bin and is reciprocated by a simple pressure- decay air circuit. The rake is attached to a swing arm mounted on the cylinder’s yoke. After we learned that the circuit performs best when the 4- way valve exhaust ports are choked to provide sufficient backpressure, the system has run without problems.
Matthew Chan
Dan Martina
Kawneer Co. Canada Ltd.
Scarborough, Ontario
