METHOD OF COOLING CRACKED GASES OF LOW BOILING HYDROCARBONS

摘要

1432403 Pyrolysis of hydrocarbons MITSUBISHI JUKOGYO KK and MITSUBISHI PETROCHEMICAL CO Ltd 3 July 1973 [4 July 1972] 31660/73 Heading C5E Olefins are produced by pyrolysis of a hydrocarbon feed in a pyrolysis tube at 750-900‹ C. followed by quick cooling of the cracked gas in a quenching device to a temperature below 450‹ C., wherein there are maintained at a temperature below 500‹ C. any metallic surfaces of the transfer portion which come into contact with cracked gas which has a mass velocity below 50 kg./m.2 per sec. and is at a temperature above 600‹ C., said transfer portion extending from the outlet port of the pyrolysis tube to the areas of the quenching device where the cracked gas is cooled quickly. The hydrocarbon feed may be a normally gaseous paraffin or a low boiling naphtha. The quick cooling device may be a multitubular heat exchanger. The transfer portion may be cooled by means of water flowing through a cooling coil, the heat energy of the cracked gas being recovered as high pressure steam. Steam may be fed to the pyrolysis tube.