Patent GB-685056-A (GB)
Title: Improvements in or relating to a reactor for and method of converting heavy liquid hydrocarbons into vaporous products and coke
IPC: C10B55/06
Filed: 1949-09-06
Abstract: Heavy liquid hydrocarbons such as bottoms are cracked to produce volatiles and a coke residue by feeding preheated <PICT:0685056/III/1> <PICT:0685056/III/2> <PICT:0685056/III/3> particle form contact material in one or more streams into the top of a reactor chamber, the streams forming flowing piles on the top surface of a gravity-packed bed of the particles moving down under gravity in the reactor, and feeding the liquid hydrocarbons into the streams of contact material or into the top portion of the flowing piles.  The vapours which first flash off and those resulting from cracking during the downward passage of the oil in the bed are drawn off for further treatment and dry particles with a coke deposit are withdrawn at the bottom of the reactor and recirculated until grown to desired size.  The bed particles may be, e.g. petroleum coke, pumice, spent cracking catalyst or crushed fire-brick.  In the apparatus of Fig. 1 the insulated reactor 1 has a baffle plate 6 across its upper part from which depend nozzles 7, e.g. of circular or elongated cross-section, through which bed particles from a hopper and preheater 22 flow into the reactor.  The particles build up into continuously moving cones or ridges at the top of the downwardly moving bed and pipes 8 are buried in these piles near their apices, the pipes having holes through which the oil flows outwardly and downwardly into the piles.  The pipes are supplied from a manifold fed from line 10 and heater 9 and the whole pipe assembly can be removed as a unit for cleaning.  Gases collecting in the free space beneath the baffle 6 are drawn off at 32.  Purge steam is admitted at 30 and 31.  The bottom of the reactor has flow control plates 11 and the outflow is regulated by a valve 14.  Make-up material may be introduced at 15.  The particles from the reactor are raised by elevator 13 and discharged into a grader 17 from which fines are discharged at 19, large particles (coke product) to line 20 and the remainder to preheater 22.  Part of the coke product may be crushed at 21 and returned to the cycle at 15 if desired.  The remainder may be partly calcined at 33 to remove remaining volatile material, the products of combustion being utilized to assist in the heating of the preheater 22.  Further heat is supplied by burners 23 supplied with fuel gas and air from lines 25 and 26.  Products of combustion are withdrawn at 28.  In a modification oil feed pipes are located on either side of elongated nozzles 7 at their lower ends and direct oil into the sides of the flowing piles of particles.  Alternatively the baffle may have rows of circular nozzles with oil pipes disposed between the rows to project oil into the sides of the resulting conical piles.  In a pilot-scale plant, Fig. 7, oil is injected into the upper part of a conical pile of particles forming in the reactor 44 below a vertical feed pipe 46 from an annular feed passage 53 surrounding the lower end of the pipe.  Flashed and cracked vapours are taken off at 50.  In the arrangement of Fig. 11 oil is introduced through pipe 62 into the centre of a flowing column of particles fed into an outer concentric tube 60 from the elevator 13, the particles and oil being mixed by flowing over a series of baffles 64-67 increasing in size downward, the last baffle directing the particles into an annular flowing pile 68.