Coal lamella
Carbon lamellas - often also referred to as carbon slide valves - are used in compressors and pumps to seal between the rotor and the housing chamber . They are used, for example, in dry-running rotary compressors and vacuum pumps as well as in wet-running vane pumps and drive slide meters. Despite the low specific weight of coal , the centrifugal force of the rotating rotor is usually sufficient to provide a sufficient seal against gaseous media.
Carbon has largely established itself as a material for slide gate valves, primarily due to its very good sliding and dry running properties, a very low coefficient of friction with little wear and tear, and high chemical resistance. Gate valves made of carbon-graphite materials also have their advantage through their operation in dry running, where they do not require any oil or similar lubricants due to their self-lubricating properties. For example, they can easily be used in printing machines , in silo vehicles in the food industry or in medical technology. A particular advantage of wet running pumps is their chemical resistance to aggressive media. Complete pumps can also be made from carbon-graphite materials; an application example for this is the use for the extraction of toxic and slightly explosive gasoline vapors at fuel pumps. Advantage: no sparks that can occur when using metallic components.
Counter-rotating pairs
As counter-rotating pairs (housing material) of carbon lamellas are particularly suitable:
- Gray cast iron
- Carbon / graphite materials
- Chrome steel cast
- hard chrome plated, hard nickel plated steel
- Cast aluminum, corundum coated
- Carbon graphite materials
When used in wet-running vane pumps or drive slide meters, the carbon lamellas are hardly subject to wear, even in liquids with a low hydrodynamic lubricating effect. In dry running compressors or pumps, however, significant wear is to be expected. This depends on the sliding speed and the sliding surface temperature. A certain amount of wear when running dry is even desirable, since graphite itself serves as a lubricant.
Applications
A distinction can be made between two main areas of application for the carbon lamellae or carbon slide valve: Use in dry or wet operation.
Dry running rotary compressors and vacuum pumps are preferred in the following applications:
- Data processing systems
- Printing machines
- Paint and varnish spraying devices
- Fresh air supply
- Medical equipment
- Car central locking
- Car seat adjustment
- Packaging machines
- Petrol suction at petrol pumps
Wet-running vane pumps and drive valve meters are found in:
- Petrol and diesel feed pumps
- Dosing devices
- Beverage filling machines
- Aircraft supply systems
- Medical equipment