US1906864A - Method of coking hydrocarbons - Google Patents

Description

Patented li/lay 2 1933 artnr ALEXANDER S. KNOWLEES AND CHARLES W. ANDREWS, 0F CHICAGO, ILLNOS, AS-

SIGNRS TO TAR do PETROLEUM PROCESS COMPANY, 0F CHICAGO, ILLINOIS, A.`

METHGD 0F COKNC-r HYDROCARBGNS Application filed 'March 5,

lhis invention relates to anew and improved method for the treatment of hydrocarbons, and more particularly to a method of treatment of such material whereby the volatile constituents are driven oit and the solid residue is coked. llt relates to the treatment ot any hydrocarbon material, whether normally in liquid form or capable of liquefaction by heat. While it is particularly applicable to the treatment of hydrocarbon such as the heavy residueof cracking stills in the petroleum industry, it is also applicable to the treatment of any other hydrocarbon or similar materials.

`This invention is in the nature of an improvement or modification of our invention disclosed in our copending application Serial Nd 277,618, led May 1t, 1928,

'llhe process may be described briefly as the treatment ot hydrocarbon in liquid form, which. comprises depositing suchV hydrocarbon in a closed chamber on a highly heated door, the hydrocarbon being heated through this door and gradually building up a layer ot coke upon the iloor. rlhe rate ot deposit of the material and the rate ot input to the door are so related that a layer ot substantially liquid material is maintained upon the layer ot coke throughout the continuation o' the process. At intervals the deposit ot material in liquid form may be stopped while the input ot heat may continue until the entire liquid remaining in the chamber has been reduced tocoke, or the process may be interrupted without completely coking the liquid layer The layer of solid material is then removed from the chamber and after the chamber is closed the process may continue as before.

llt is an object of the present invention to provide a new and improved method for the treatment of hydrocarbon material in liquid form.

llt is a further object to provide a process of this character in which the material is so treated as to crack and break down the material and to volatilize the lighter constituents and to reduce the residue to a merchantable coke.,

llt .is-also an object to provide a method ot 1929. Serial No. 344,131.

this character which may be carried on an It is a further object to provide a new and improved method for the removal of the solid residue or coke produced by our method.

llt is an additional object to provide a method which may be carried on substantially continuously.

Other andturther objects will appear as the description proceeds.

We have shown the one preferred form oit apparat-us for carrying out our invention in the accompanying drawing in which- Figure 1 is a longitudinally vertical section through the apparatus;

hdigure 2' is a transverse vertical section; an

Figure 3 is a. fragmentary vertical section showing a modified form of construction.

Referring first to the :torni of construction shown in Figures 1 andQ, the enclosed cham ber 11 is shown provided with the floor 12.,

' rllhis lioor is formed of highly refractory material or heat resistant metal, and is heated` from below by means of combustion which takes place in the lues 13 located below the tloor. 'llhese lues vmay be heated b, means ot uel introduced through the fue supply pipe 14, located at the opposite end of the lines. 'llhe iues 13 are connected to the regenerators 15, which are connected in turn to the passages 16 which serve alternately to introduce the airofor combustion, and to carry od the products of combustion. llt will be understood that the combustion in this iue is shown as carried on alternately air passes up through opening 17 to mingle with the fuel to cause the initial combustion, and additional air will pass up through open-= ings 18 and 19 to cause additional combustion. By this means combustion may be carried on for the major portion of the length of the line, and the floor, therefore, heats substantially uniformly throughout its length. lnstead of reversing the combus-= tion with regeneration, other methods ot heating the floor such as the use of recuperators, may be utilized.

-rom opposite ends. On the incoming end r The upper portion of the chamber 11 is closed by the top which may be made of metal and preferably may be covered with any material adaptedto minimize the loss through radiation. rlFhe ends of the cham'- bers 11 are closed by doors 21 which may be removed for the purpose of discharging the coke from the chamber. A second chamber is located above the coking chamber 11 and extends substantially from the middle of the roof 20. This chamber 22 is provided with a cylindrical basket 23 carried on trunnions 24 and 25. The. trunnion 25 is provided with a power supply pulley 26, to which power may be brought from any suitable source. By means of power applied to pulley 26, the basket 23 may be rotated as desired. rlhe inlet chamber 27 is located immediately above lthe basket 23, and contains the two downwardly directed inlet nozzles 28. rlfhese nozzles are connected to the supply pipe 29, the connection being controlled by valve 30. IThe oftake passage 31 leads from the upper portion of the inlet chamber 27.

The bottom of the upper chamber 22 is preferably closed by a butteriy valve 32 provided for that purpose, as it may be desirable to close off this chamber when the ends of the coking chamber are open for the removal of the coke.

Inside the chamber 11 are provided the Z- bars 35 which extend the length of the chamber and have the inwardly extending flanges 36 which serve as guides and supports for the pusher used to push the coke from the floor 12. The head of the pusher has been shown at the right of Figure 1 and comprises the lower portion 37 which extends the full width of the floor, the upper anges 38 to rest on the guide flanges 36 and the push rod or shaft 39. rl`hrust may be applied to shaft 39 in any desired manner and by any desired form of apparatus, such for example as the coke pushing machine used for rectangular beehive coke ovens.

The form of construction shown in Figure 3 differs from that of Figures 1 and 2, in that the upper chamber 33 is provided with a plurality of downwardly sloping baffles 34 to receive the material from the inlet pipes or nozzles 40 and to expose the material to Contact with the ascending gases. These baffles therefore perform the same function as that performed by the rotating basket, in the first form of construction.

In the operation of the apparatus shown, to carry out our improved methods the floor 12 is first raised to a coking temperature by means of combustion 'in the flues 13. The

material to be treated is introduced through Lacasse.

the oven directly from such prioi` process while still hot from previous distillation or cracking action.

rllhe material falls from nozzles 28 upon the basket 23 which basket is partially filled with a mass of loose material such as coke. @ther materials than coke may be used as the purpose of this loose material is to provide extended surfaces to receive the liquid being treated in order to give a more extended contact between the material being treated and the ases rising from the coking chamber. rlhe asket 23 is rotated to more uniformly distribute the material being treated throughout the loose material in the basket, and to prevent clogging of the coke or the building up of the material thereon. rihis rotation, however, may be quite slow, as for example approximately one rotation per minute, or it may be even slower if desired. "While some of the solid residue from the liquid being treated will be deposited upon the material in the basket, due to the rotation of the basket there is a constant abrasion of the loose material. rlhe speed of rotation may be so maintained as to substantially knock o' or abrade the material as fast as it is deposited on the loose material in the basket. ln this way the loose material in the basket may be maintained at substantially a consta-nt size and at substantially the same amount.

From the basket 23 the material drops to the highly heated floor 12. On the floor the liquid spreads out and the floor is covered with a layer thereof. This layer of liquid is highly heated through the heat transmitted upwardly through the floor, and the lower portion of the layer is coked. The process continues with material being deposited in the upper chamber and dripping from the basket to the door. The rate of deposit of material and of input of heat to the floor are so related as not to coke all of the material on the ioor and there is maintained on top of the coke layer a layer of liquid. Between the hard coke on the bottom and the comparatively liquid top will be an intermediate layer varying in solidity and density. From the liquid layer the vapor and gases given olf pass upwardly through the upper chamber 22, through the inlet chamber 27 and out through the passage 31. During their passage these gases are brought in contact with the liquid dropping from the basket 23, as well as with the thin film of liquid covering the loose material in the basket or the baffle plates, if that form of construction is used. rlhe temperatures of these gaseousproducts will be maintained substantially constant throughout the operation, since this temperature is that at which the gases are driven off or volatilized. The thickness of the layer of liquid in the chamber is controlled to maintain this temperature substantially constant.

lll)

Leoaeee There is, due to the layer of coke and of liquid on the floor, very little heat radiating from the floor up to the basket 23, but the heat at the basket is that carried by the ascending gases. Due to this fact the basket 23 may be located well above the floor and in a separate chamber as shown. There is little loss of temperature of the gases in the short distance between the Hoor and the basket in the upper chamber, all of this distance being within the enclosing chambers.

Tt will be understood that the layer of coke building up on the floor acts in the nature of an insulator and after it has reached a predetermined depth it is not economical to continue to build up upon it, since the heat of further coking must be transmitted through this coke layer. Therefore, after the layer has reached a predetermined depth the supply of additional material to be heated is stopped by closing the supply valve 30. The liquid material in the basket may then be permitted to largely drip to the iioor during which the heating of the floor may be continued. Tf desired, the heating may be continued until the liquid layer is fully or partially coked or the material on thepiloor may be removed without additional delay. Before the doors 21 are opened for the pushing out of the coke, the valve 32 is closed to separate the upper chamber and basket from the coking chamber. This is desirable to prevent any ash of combustion passing into the upper chamber when air is admitted to the highly heated coking chamber bv the opening of the doors.

After the coke is removed, the doors 21 are'closed, the valve 32 is then opened and the supply of material to be treated again started. The supply of heat to the floor 12 may be interrupted vwhile the doors 21 are opened for the removal of coke. Since this removal may be carried on by means of apparatus for that purpose in a very few minutes, there is very little loss of time or of heat during the removal. The doors may be quickly brought up again to the coking temperature.

When the deposit of material is started again after each removal of coke, there is no solid layer of cokeon the oven floor to support the liquid layer as there is as the deposit and coking progress. There is normally, however, a layer of coke dust or breeze left on the Hoor after the coke is pushed out. This results from the breaking up of the coke as it is pushed out and the abrasion of the pieces against each other. This layer of coke breeze prevents the next liquid deposited from` coming into direct contact with the heated floor and therefore prevents too rapid coking of this liquid. The coke breeze willv become a part of the next layer of coke as it is formed. v

Since in this process we mamtain a layer of liquid materialupon the layer of coke, it is not necessary to apply the liquid at a number of points throughout the floor area. We have found in actual operation that even if the liquid is supplied only through a small area such as that of the chamber 22, it will, upon reaching the door, spread out to the edges of the floor. The coke layer built up will be found to be substantiallyequal in thickness throughout the lioor area. Tt is highly desirable to be able Ito deposit the liquid in but few points since materials of this character tend to clog nozzles or other means for depositing small amounts of material. By deposit in a localized area the nozzle flow may be made of suicient quantity so as to substantially prevent clogging, and also the number of nozzles used may be so small that it is a simple matter `t0 take care of them and maintain them in proper condition.

l/Vhile we have shown one preferred form of apparatus especially adapted for carrying out our improved method, it is to be understood that the method may be carried on in other forms of apparatus and further that our method is capable of modification to adapt it to various forms of apparatus and various materials to be treated. We, therefore, contemplate such changes and modifications as come within the spirit and scope of the appended claims.

We claim:

1. The method of treatment of heavy hydrocarbon material in liquid form, which comprises depositing the material in a closedV chamber upon a highly heated floor, the rate of.deposit and the heat input to the ioor being such as to cause coking on the floor and to maintain a layer of substantially liquid material in the chamber, and periodically stopping the deposit of material, continuing the application of heat to the liquid layer until it is coked, and removing the coke from the chamber. v

2. The method of treatmentof heavy hydrocarbon material in liquid form, which comprises depositing the material in a closed chamber upon a highly heated Hoor, the rate of deposit and the heat input to the floor'being such that the material is coked progressively from below, building up a layer of coke on the loor and maintaining a layer of the material in substantially liquid form upon the coke layer, periodically stopping the deposit of material, continuing the application of heat to the liquid layer until it is coked, and removing the coke from the chamber.

Signed by ALEXANDER S. KNowLEs at New York city, New York, this 4th day of March. 1929, and by CHARLES W. ANDREWS at Chicagd, Illinois, this 28 day of lFebruary, 1929.

`ALEXANDER S. KNOWLES.

CHARLES W. ANDREWS.

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