System Overheats on Custom Drum Crusher

By Robert Sheaf, CFPAI/AJPP, CFPE, CFPS, CFPECS, CFPMT, CFPMIP, CFPMMH, CFPMIH, CFPMM
CFC Industrial Training

A horizontal press crushes empty 30- and 55-gallon drums, and a drip pan captures any liquid that is flushed out. As it crushes the drums, the machine punctures a hole inserting a spray nozzle in one end and several holes in the lower area of the opposite end for a drain. The company assumes the captured waste is hazardous, and they send it to another EPA-approved company. The drum material goes to a mill that melts it down and works it into various shapes, like angles and bar stock.

The company had a problem with the hydraulic unit overheating and determined it was due to corrosion build up in the copper tubes in the four-pass water-cooled heat exchanger used to remove excess heat. They routed out and cleaned the tubes and reassembled the unit with new end-cap gaskets and zinc anodes. They were surprised that the system still experienced overheating problems. They were able to increase the water flow, but that did not help.

Their outside hydraulic service company assured them that the system was operating as designed and that it must be a heat exchanger problem. The service company wanted to sell them a larger heat exchanger, but the customer balked at the cost because the existing one did well for many years.

What could be the problem?