GB274763A - An improved process and apparatus for cracking hydrocarbons - Google Patents

Abstract

274,763. Arnold, C., (Standard Development Co.). March 14, 1927. Hydrocarbons, cracking.-Relates to cracking hydrocarbons, particularly the residuum of high grade crude oils which have been distilled for the removal of gasoline, and consists in heating the oil to a cracking temperature in a coil 23 and then passing it into an enlarged thermally insulated region 27 wherein it undergoes cracking under pressure, the clacked product being passed at reduced pressure directly and without substantial loss of heat into a chamber 1 connected to a bubble-tower 5, heat being supplied to the chamber 1 in order to increase the yield, of gas oil. Cooling fluid, preferably the oil to be cracked, is supplied to a coil 8 in the bubble-tower and passes thence to a cooler 17 for cooling tar delivered from the chamber 1 through a valve 19. The cooler 8 may be byepassed by means of valves 14<1>, 15<1>. The distillate from the bubble-tower is delivered through a pipe line 9 for subsequent fractionation, the gas oil being taken off as a separate fraction by means of a pan 7 and a line 11 provided with a valve 12. A cooler 8<1> through which the gas oil passes on its way to a tank 13 is served by a bye-pass from the stock oil flowing from the cooling coil 8. A pump 22 fed by the stock oil after it has been preheated in the various coolers delivers the oil under pressure to the cracking coil 23 mounted in a furnace setting 24. The cracking is completed in thermally insulated drums 27 arranged in series or in parallel and controlled by valves 26. Vapour and liquid together are discharged from the drums through a pressure controlling valve 36 to the chamber 7 which is preferably heated wholly or partly by internal flues 3 to minimize coking. The gas oil may be mixed with the original stock to form a new stock for the same cracking oil, or it mav be cracked in a separate operation. The tar from this operation may bo blended with the tar from the original stock to yield a fuel oil product. Numerical data of working pressures and temperatures and of approximate percentage yields are furnished in the Specification.