The pyrolytic graphite block

Pyrolytic graphite is a new carbon material, high purity hydrogen gas under certain furnace pressure, in 1800 ℃ ~ 2000 ℃ on graphite substrates by chemical vapor deposition of pyrolytic carbon of high crystallization orientation, it has a high density (2.20 g/cm), high purity, impurity content (0.0002%) and heat, electricity, magnetic, mechanical property anisotropy. At about 1800 ℃ can still maintain a vacuum of 10 MMHG.

Heat transfer process needs to absorb a lot of heat. The heating methods in industry can be divided into self-heating process and external thermal process. Limestone pyrolysis generated, for example, the temperature above 800 ℃, and even in the presence of oxygen and does not affect the reaction process, thus can be used directly calcined industrial furnace for heating process. For pyrolysis oil fraction, reaction temperature above 750 ℃, and require the lowest possible hydrocarbon partial pressure, product for combustible gas, so commonly used partition way of heat transfer (such as tube furnace cracking) or by direct heating heating medium (such as sand regenerative furnace cracking, cracking and high temperature steam cracking, etc.) of the external heat process. But it can also be used to heat a part of the raw material for the thermal process, such as natural gas or heavy oil burning pyrolysis of acetylene, carbon black and so on. Because of the advantages of low carbon olefin in tubular furnace cracking, this method has been used in recent petroleum hydrocarbon cracking.