US2279524A - Coking chamber - Google Patents

Description

April 14, 1942. l.. w. Hensema cox-ING .CHAMBER Filed Aug. 15, 1940 FIG. 3

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:NveNroR LEONARD w. ROBBIE ATTORNEY Patented Apr. 14, 1942 UNITED STATES APATENT oFFicE como CHAMBER Leonard W. Robbie, Chicago, lll., assigner -to Universal Oil Products Company, Chicago, Ill., a corporation of Delaware Application August 15, 1940, Serial No. 352,735 3 Claims. (Cl.- 202266) This invention particularly relates to an improved form of vessel or receptacle of the type in which hydrocarbonaceous materials such as petroleum oil, coal, peat, lignite, oil shale, asphalt, pitch, resin and the like or mixtures of such materials lare distilled to substantial dryness and wherein the resulting substantially solid carbonaceous residue or coke is allowed to accumulate during the distilling operation'and subsequently removed from the vessel.

Coking chambers of this general type are widely utilized in conjunction with or as an integral part of cracking units and, due to the capital investment represented, as well as the demand for cracked gasoline, it is of primary importance to operate the cracking unit as continuously as possible with 'a minimum of nonproductive time for cleaning out the equipment and preparing it for further operation. It is common practice to employ a plurality of alternately operated coking chambers, one or more of which are -cleaned and prepared for further operation, while the coking operation is continued in another or others of the group. This practice makes possiblemuch more prolonged periods of operation between shut-downs and the use of a plurality of coking chambers of suilicient individual capacity, in conjunction with modern methods of coke removal, eliminate coking as the bottle neck in a continuous cracking and coking operation. However, the coking step is still an item of considerable expense, due not'only to the cost of the coking equipment itself, but also to the cost of modern coke removal equipment and the labor involved in its operation.

The improved form of coking chamber herein provided materially simplies and expedites coke removal and materially reduces the cost of coke removal equipment, as compared with that required when conventional coking chambers are employed.

This improved form of chamber departs from the conventional cylindrical coking chamber with top and bottom man-ways of reduced diameter in relation to that of the chamber, in that it is progressively larger in diameter from top to bottom, resembling a truncated cone in shape, and having a removable lower head which, when removed, leaves a bottom opening in the chamber which is the full area of the chamber' at its point of greatest diameter.

With this form of vessel, substantially the entire mass of coke accumulated in the chamber may be pulled or dropped through the bottom With opening and, to facilitate this, when required, I provide an interior structure which 'is placed or hung within lthe chamber before it is headedup and placed invoperation. This interior structure comprises a plurality of vertically spaced horizontal perforate or open-work partitions which are united by cables, rods or vthe like and become enmeshed with. the coke mass deposited in the chamber. By pulling the free lower end of a cable, chain or the like attached to the structure, the entire mass of coke is loosened from the sloping chamber walls and falls through the lower opening. Thus, in'most instances, except for a small amount of scaling-down or hand-cleaning sometimes required abouty the inlet and outlet connections and upper man-way and cleaning of the lower head,"the entire vessel is cleaned in a single simple and rapidly accomplished operation and may be immediately headed up and conditioned for further service by purging, preheating and the like, as required. r Althougha full diameter removable lower A head involves the use of heavy ilanges and bolting and is an item of greater expense than a small diameter lower man-way such as employed in conventional coking chambers and makes a vessel of the improved form herein provided more expensive to construct than a conventional coking chamber of. equal size, this 'additional expense is largely nullied and in many instances more than compensated for by the use of smaller coking chambers. This is possible when the improved form of chamber herein provided is employed, since clean-out time is materially reduced. This permits shortening of the operating cycle, with respect to the individual chambers, by a corresponding amount and thus reduces the required capacity of eachy individual chamber. -As an alternative, in' installations which would require three or more conventional coking chambers of a given capacity, one or more may be eliminated, when chambers of the ini-'-l proved form and of equal individual capacity are employed, due to the shortening. of the cleanout time required with the improved form of chamber and the improved means of coke removal provided. 4

The accompanying diagrammatic drawing illustrates the improved form of chamber` provided by the invention, including one specic form of apparatus for facilitating the removal of coke therefrom.

Fig. 1 is a cross-sectional elevation of the chamber with the removable lower head in place and a suspended interior structure which serves shrinkage of the external force is to facilitate removal of the coke mass as a unit.

Fig. 2 is a plan view of one of the open-Work members of the suspended interior structure.

Fig. 3 is an enlarged detail, shown partially in section, of the suspending mechanism designated by the reference numeral I1 in Fig. 1, and;

Fig. 4 is a plan view .of the apparatus shown in Fig. 3.

Referring now particularly to Fig. 1, the sloplng Walls designated by the reference numeral I, terminate in an upper elliptical head Zand/a lower flange 3. Preferably, the truncated conical shell I is made upnofvafplurality of rolled steel rings welded along their vertical and horizontal seams in the approved conventional manner with the welding beads; on the interior of the vessel ground substantially flush with the walls, to eliminate protrusions which would interfere with the removal of the coke mass in the manner provided and hereinafter described.

It will be noted with reference to the drawing that the walls I of the vessel flare slightly outward from -top to bottom and, preferably, the interior diameter of the vessel increases uniformly from the top downward to substantially the face of the lower flange 3. This lower flange is also preferably welded to the shell I and the upper head 2 is also preferably welded Ato the shell.

The upper head 2 is provided, in the case here illustrated, with a central flanged man-way nozzle 4 and a companion blind flange or cover plate 5 bolted to the flange of the man-way nozzle, as indicated, and preferably a gasket or suitable ground u'oint facing of any desired conventional form, not illustrated, is provided between the flanges to maintain a tight joint and prevent leakage. A flanged inlet nozzle connection 6 and a flanged outlet nozzle connection Iis also pro- `vided in the upper head 2, in the case here ils lustrated.

The lower flanged head I3v of the vessel is releasably secured to flange 3`by bolts 9 and the flanges are suitably faced to accommodate a gasket I0 or'to provide any conventional form of ground joint facing therebetween to maintain a tight joint and prevent leakage. A flanged nozzle connection II is provided centrally in the lower head 8, in the particular case here illustrated. This nozzle II may serve as a drain line connection and/or as a means of introducing steam, water or other suitable cooling material into the mass of coke accumulated in the chamber before the lower head is removed, to purge the chamber of hydrocarbon vapors and gases,

hasten cooling and shortenthe clean-out period.

When the weight of the mass of coke accumulated within the chamber is sufficient 'to overcome the adhesive tendencies between the outer surface of the coke mass and the relatively smooth interior walls of the chamber, the coke mass will,

in the absence of means for preventing such action, fall from the chamber when the lower head 8 is removed. This will ordinarily occur when relatively dense hard coke is formed and rupture of the bond between the coke mass and the chamber walls is often accomplished or facilitated by coke mass which `occurs when it is cooled by the introduction ofl steam, water or the like, as above mentioned. On the other hand, with some types of coke an application of required to free the mass from the walls of the vessel, but, by virtue of the sloping walls and the elimination of obstructions therefrom, friction between the chamber walls and the moving mass of coke is substantially eliminated and, once the bond is broken between the chamber walls and the coke mass, the latter will wall through the lower opening.

5 To obviate hazard and eliminate the possibility of unintentional dropping of the coke mass before the lower head is completely removed and the workmen have'retreated to a point of safety, the invention provides means for retaining the coke l0.mass in the chamber after the lower head is removed therefrom until its removal is desired.

The same means may also be employed, when required, for imparting the initial externally applied force to the coke mass to free it from the 15 chamber walls. In the particular case here illustrated, the coke-supporting and disengaging means comprise a plurality of vertically spaced web-like members I2 of which Fig. 2 is a typical plan View. Each of these members comprises o radial rods or bars I3 each secured to a plurality of circular metal hoops or rings I4. Each of the members, I2 extend substantially across the diameter of the portion of the chamber in which they are located and they are spaced and held together by members I5 which may be rods or, preferably, are flexible members such as a chain,

, wire cable or the like. The members I5 are united above the uppermost member I2 and terminate in a suitable loop or the like I6 by means of which the assembly is suspended within the chamber from Imember I1 located within the upper man-way nozzle. The members I5 are likewise united beneath the lowermost member I2 and terminate in a suitable loop or the like I8 attached to a hook I9 on the removable lower head of the vessel.

As coke is deposited and built up within the chamber, the members I2 become embedded therein but their form is such that they offer no appreciable resistance to the flow of fluids entering and leaving the chamber nor to the revolution of vapors and gases from the mass of semisolid material undergoing coking. The members l I2 and I5 serve to unite the entire mass of coke which is finally deposited within the chamber so that it may be removed therefrom substantially as a unit and, preferably, these members are of suflicient size and strength to support the coke bed, when necessary, and prevent its unintentional dropping when the bottom head is removed.

Referring now particularly to Figs.y3 and 4,

member I'I comprises a pair of br'ackets 2li-welded or otherwise rmly attached to the neck of manl way nozzle 4 and an arm 2| hinged to the brackets by means of pin 22 and terminating at the opposite end in a hook 23. A metal ring or the like 24, adapted to pass around the protruding corners 25 of brackets 20, serves to retain arm 2I C) in a substantially horizontal position to support the assembly comprising members I2 and I5, ex-

cept when it is desired to remove the coke mass from the chamber, the ring 24 being adapted to slip over the ends 25 of brackets 20 toward the hooked end of member 2|, allowing the latter to drop and release loop I6 (see Fig. 1) when it is desired to remove the coke mass.

In cleaning the chamber after it has been isolated from the rest of the system, substantially 7n purged vof vapors and gases and sufficiently cooled, the lower head 8 and the upper cover plate 5 are removed, loop I8 is then detached from hook I9 and, when required, is secured to a cable onthe drum of a suitable power operated winch or the like, not illustrated, during which time unintentional dropping of the coke mass is prevented by leaving the upper end of members I attached to the supporting mechanism II. Then, when everything is in readiness for dropping the coke mass from the chamber, with the area beneath the chamber cleared and workmen out of the way, ring 24 is driven from the supporting brackets 2U of member II, allowing arm 2| to drop and release the loop I6 at the upper end of members I2 from hook 23. If the coke mass then does not drop from the chamber by its own weight, power is applied to the winch and transmitted through members I5 and I2 to the entire mass of coke which is thus freed from the chamber walls and drops out ofthe chamber. Preferably, the winch is located a considerable distance from the chamber so that the assembly comprising members I2 and I5 and the coke which adheres thereto may be dragged from beneath the chamber to a convenientI location at which said adhering coke is removed. Preferably, to avoid delay a duplicate assembly of members I2 and I5 is provided which is ready to be hung within the chamber as soon as the coke mass is dropped therefrom and any required incidental cleaning of the nozzles and the like is accomplished. lThe chamber may thus be heated up and prepared for further operation within a short time (normally approximately 30 minutes and often less) after it is opened for cleaning.

I claim as my invention:

1. A vessel of theclass described comprising, in combination, a substantially vertical, substantially cylindrical metal shell normally closed at its upper end and of progressively increasing internal diameter from its upper to its lower end,

the interior surface of the sloping walls of the shell being substantially smooth and free of obstructions and said walls terminating at their point of greatest diameter, a metal head spam ning the entire diameter of the shell at its lowermost point and releasably secured to the shell, and a plurality of rigid perforate supporting members disposed at vertically spaced elevations within said shell and releasably suspended from the upper end of the vessel by means accessible through an opening therein provided with a removable cover plate, each of said web-like members progressively increasing in diameter from the upper end of said' shell to the lower end thereof.

Z. A vessel of the class described comprising, in combination, a substantially cylindrical metal shell normally closed at its upper end and .of progressively increasing internal diameter from its upper to its lower end, and open at its point of greatest diameter, the interior surface of the sloping walls of the shell being substantially smooth and free of obstructions, a metal head spanning the entire diameter of the shell at its lower end and releasably secured to the shell, and a plurality of openwork, substantially discshaped members progressively increasing in diameter from top to bottom of the said'shell disposed at vertically spaced elevations within said shell and releasably suspended from the upper end of the vessel by means accessible through an opening therein provided with a removable cover plate.

, 3. A vessel of the class described comprising, in combination, a metal shell of substantially truncated conical shape internally, said metal Shell having an integral upper head provided with a manway nozzle and removable cover plate therefor, said shell being of progressively increasing interior diameter from its upper to its lower end and open at said lower end, the interior surface of the sloping walls of the shell being substantially smooth and free of obstructions, a metal head spanning the entire diameter of the shell at its lower end and removably secured to the shell, suspension means comprising a hinged hook adapted to be fixed in operative and released to inoperative position, said hook being secured to the vessel adjacent the upper end of the vessel and accessible upon removal of the cover plate from said manway nozzle, a flexible hanger member suspended at its upper end from said hook and adapted to be releasably secured at its lower end to the removable lower head of the vessel, and a. plurality of open-work, disclike members disposed at spaced vertical elevations within said shell and supported by said hanger member. f

LEONARD W. ROBBIE.

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