Carbon-graphite material targets dry environments

Metcar 1515 is suitable for bearings and thrust washers in a variety of applications, including gypsum board dryers, kiln cars, oven dryers, electrostatic precipitators, ventilating dampers, furnaces and conveyors.

Metcar bearings are self-lubricating, non-galling, dimensionally stable and have high compressive strength.

Offering good thermal properties and high electrical conductivity, the bearings and bearing assemblies are a suitable carbon-graphite solution for applications in harsh operating conditions.

One illustrative key use of Metcar Grade 1515 is for electrostatic precipitators used on recovery boilers in large paper mills.

The precipitator removes 'salt cake' ash from the boiler exhaust gas, which drops onto a drag chain conveyor that can be about 12ft wide and 50ft long.

The drag chain is driven by sprockets on 3-5in diameter steel shafts that are held by pillow block bearings made of the Metcar Grade 1515 self-lubricating bearing material.

Oil/grease lubricated bearings would not be satisfactory for this application because the temperature at the bottom of the electrostatic precipitator is about 350F.

Also, the bearings' inaccessible location would make it difficult to re-lubricate conventional oil/grease lubricated bearings.

Similar bearings are used in drag-chain conveyors that remove the ash from the bottom of large boilers that burn municipal waste, waste tree bark and other solid fuels in lumber mills.