Carbon graphite is not a common material choice for the average consumer. While many of us may not be aware of it, carbon graphite parts are used all around us.
Keep reading to discover a few applications of carbon graphite that help move us and our materials around the world.
1. Refrigerated trucks
Refrigerated trucks are used to transport perishable goods throughout the country. The refrigeration system on trailers contain carbon graphite seals within the compressor, which pulls in gaseous refrigerant and compresses it before sending it to the condenser. Carbon graphite is chemically inert, allowing it to run in low viscosity refrigerant and act as a seal to prevent toxic refrigerant gas from leaking into the environment.
2. Automobile turbocharger
A turbocharger is fitted to a vehicle's engine to help improve the overall efficiency and increase performance. As more manufacturers are trying to find ways to improve performance while being efficient, turbochargers are becoming more common while bigger engines are becoming a thing of the past.
To make the turbochargers more efficient, variable vanes are used. This requires an actuator to penetrate the turbo casing resulting in a potential leakage point. Carbon graphite is able to withstand the high temperatures seen by the exhaust gas and engine and acts as the seal to prevent CO2 emissions from entering the atmosphere.
3. Barge pumps
The marine shipping industry moves heavy or bulky items around the world that are difficult to transport in other ways. Barges can carry cargo such as chemicals, coal, minerals, and oil. Barge pumps are used to transfer material from the barge to shore. These pumps are used to pump a wide variety of material and it is likely that the material is unknown. Carbon graphite is used in barge pumps because it offers chemical resistance to handle any toxic chemicals/liquids that are being transported.
4. Rail contacts
The rail system uses electrical relays to operate the signaling system. Electrical Relays contain electrical contacts that transmit current. In the process of transmitting current, electrical arcing can occur between the two circuits. Electrical arcing can result in metal pieces welding together. This results in a failure in the rail signaling system which can be extremely problematic as signals control the flow of rail traffic through crossings, bridges, tunnels, etc. To prevent the possibility of these contacts welding together and resulting in accidents, carbon graphite is used.
Electrically conductive material grades of carbon graphite eliminate electrical noise and arching, allowing signals to transmit clearly without the risk of parts welding together. As a result, rail signals are able to regulate rail traffic efficiently and prevent catastrophic accidents.
5. Commercial aircrafts
Commercial aircrafts are used to transport people and goods between countries and states. They face a range of environments from high and low temperatures, rain, humidity, sand, dust, etc. Carbon graphite provides numerous benefits for aircrafts because it is lightweight, environmentally durable, self-lubricating, oxidation resistant, and has a high thermal conductivity. It is commonly used in air bleed vales, jet fuel pumps and meters, and shaft seals in aircrafts. Improvements in carbon technology has allowed aircraft engine manufacturers to design more efficient engines, therefore improving fuel efficiency.
6. Spacecraft rocket booster pumps
In order for spacecrafts to be propelled out of Earth’s gravitational pull, rocket boosters are used to provide additional thrust during lift off by creating an explosion within a combustion chamber. To create this explosion, liquid fueled space crafts use fuel and oxidizers that are in liquid form - liquid hydrogen (fuel) and liquid oxygen (oxidizer). These liquid propellants are required to be stored in cryogenic conditions as their boiling points are close to -450⁰F. Once combined in a high-pressure chamber, the combustion that propels the rocket off the launch pad experiences temperatures greater than 1000⁰F.
Carbon graphite is used in these applications because it can withstand both of these temperature extremes while maintaining an efficient seal. In addition, its self-lubricating properties eliminate the need for traditional lubricants that can solidify in cryogenic temperatures.
Because cryogenic fluids are thin with very low viscosities, there is a risk of these fluids entering available porosity of a seal and vaporizing to result in blistering of the part. However, when carbon graphite is coupled with a blister resistant impregnate, the material is able to withstand the low viscosities of the oxidizer to continue to operate successfully.
Carbon graphite is used in many applications around the world to keep us moving with increased efficiency. Whether it may be in a rocket booster of a space craft, a turbocharger in a car, or a signal for a train; carbon graphite is present to aid in the successful running of these applications and many more.
For more information about carbon graphite products for your application, contact an engineer today.