Friday, September 24, 2010

Belt Conveyors

It Happened...

On June 18, 1990, a fire occurred along a belt entry. A wedge shaped rock lodged between the belt and take-up roller caused the belt to slip. The friction caused a fire at the head pulley and the second drive roller. The fire was extinguished using two extinguishers and water.

On March 18, 1998, smoke was detected near a unit belt drive. Mandoors were opened to divert the smoke. The belt slippage switch was not operating properly.

On November 1, 1991, smoke was detected in a conveyor belt entry. Elevated concentrations of carbon monoxide were not detected by the sensors 100 feet inby. Smoke and flames were observed near the drive pulley. The fire was extinguished with water.


Example of a typical belt conveyor

BELT CONVEYORS require constant maintenance and monitoring. Belt slippage tests could be designed with a handle or small hydraulic jack that permits the examiner to physically raise the belt off of a roller in order to simulate belt slippage and test for conveyor sequencing.

• ALWAYS replace worn or damaged idlers on a conveyor line as soon as possible.
• ALWAYS investigate the smell of burning rubber coming from a conveyor line.
• ALWAYS remove accumulations of float dust from conveyor lines and make certain of adequate rock dusting.
• ALWAYS plainly mark locations of fire taps along conveyor lines.
• ALWAYS make certain that threads on fire taps along conveyor lines are covered and clean.
• ALWAYS make certain that fire hose provided along conveyor lines is properly stored in containers.
• NEVER take fire hose from conveyor lines to use for purposes other than fire fighting.