Abstract: A closed reactor for the thermal cracking of heavy oils, having an internally mounted, rotatable injection pipe. The injection pipe is adapted to spurt preheated raw material under pressure against the inner wall surfaces of the reactor while rotating to remove coke which has deposited on the reactor walls during the previous cracking operation.

Abstract: A decoking apparatus suitable for use on a reaction vessel for the thermal cracking of heavy petroleum oils the apparatus essentially including a rotatable main injection pipe to be disposed in the reaction vessel and having a multitude of jet nozzles along its length, and a second or auxiliary injection pipe positioned in the proximity of the main injection pipe to inject a scrubbing liquid over the outer peripheral walls of the main injection pipe to prevent deposition of coke. The main and auxiliary injection pipes are both supplied with heavy petroleum oil to remove the coke deposition from the reactor wall by the heavy petroleum oil jets from the main injection pipe while wetting the exterior of the main pipe with the heavy petroleum oil injected by the auxiliary injection pipe.

Abstract: A decoking device suitable for use on a reaction vessel for the thermal cracking of heavy petroleum oils, including an assembly mounted on top of the reaction vessel and having a cylinder and a piston slidably and rotatably received in the cylinder, the cylinder and piston defining a scrubbing liquid chamber which is sealed from the outside. A scrubbing liquid is fed through the scrubbing liquid chamber to a main injection pipe to inject the liquid through a multitude of jet nozzles in the main injection pipe against the inner wall surfaces of the reaction vessel, the main injection pipe being connected to the piston for movement therewith.

Abstract: In a process for the thermal cracking of a heavy hydrocarbon in a cylindrical reactor, a portion of the content material in the reactor is taken out and injected back into the reactor according to a specific procedure to form a "wet wall" or liquid curtain on the inner peripheral wall of the reactor, thereby preventing coking in the reactor. The apparatus includes a radially outwardly extending interior annular recess around an upper portion of the inner wall thereof and forming a part of said inner wall and plural means for tangentially injecting the recycled liquid into said recess.

Abstract: A method for the batch thermal cracking of heavy oils, such as steam blowing for production of binder pitch, employing a reactor having a rotary injection pipe which is rotatable within the reactor. Upon completion of the thermal cracking and withdrawal of the reaction product, the injection pipe ejects preheated raw material under pressure against the interior wall surfaces of the reactor while in rotation to remove coke which has deposited on the reactor walls during the previous cracking operation.

Abstract: In a process for the thermal cracking of a heavy hydrocarbon in a cylindrical reactor, a portion of the content material in the reactor is taken out and injected back into the reactor according to a specific procedure to form a "wet wall" or liquid curtain on the inner peripheral wall of the reactor, thereby preventing coking in the reactor.