US2028166A - Apparatus for coking liquid residuums - Google Patents

Description

C. J. PRATT APPARATUS FOR COKING LIQUID RESIDUUMS Jan. 21, 1936.

Original Filed Aug. 6, 1951 3 Sheets-Sheet 1 Jan. 2l, 1936. PRATT 2,028,1'66

APPARATUS FOR COKING LIQUID RESIDUUMS Original Filed Aug. '6, 1951 s Sheets-Sheet 2 5 Sheets-Sheet 3 c. J. PRATT APPARATUS FOR COKING LIQUID RESIDUUMS 1 Filed Aug. 6, 1931 Origuia Jan, 21, 1936;

Patented 1.... 21, 1936 UNITED s'ra'rrss 2,il28,166 APPARATUS FOR COKING LIQUID BESIDUUMS at... John Pratt, St. Louis, Mo., assignor, by

mesne assignments, to J. P. Devine Manufacturlfig Co., Inc., Mount Vernon, 111., a c orporation of Illinois Application August 6, 1931, Serial'No. 555,401

P Renewed September 24, 1934 1 Claim. '2021 17) This inventionrelates-to an apparatus for forming coke, and with regard to certain more specific features, to the method of, and apparatus for forming coke from the residuums of an oil refinery. Among the several objects of the invention may.

be noted the provision of a process for continu'- ously converting heavy residuums into coke; the

provision o'f'a process of the class described which subjects said residuums to a cracking and distilling operation and then to a coking operation; a

the provision of a process of the class described in which superheated steam is admitted to d y and render the product porous; the provision of a process of theclass described which is continuous, economical, and which produces a high grade coke with simplified apparatus. Other ob- Jects will be. in part obvious and in part pointed out hereinafter.

' go 'Iheinvention accordingly comprisesthe elements and combinations of elements, steps and 7 sequence of steps, features of construction and synthesis, and arrangements of parts, which will be exemplified in the structures and processes 35 hereinafter described, and the scope of the application of which will be indicated in the following claim.

In the accompanying drawings, in which are illustrated one or more of various possible em- 39 bodiments of the invention,

Fig. 1 is a vertical longitudinal section, of a coking-unit embodying the invention;

Fig. 2 is a top plan view of the unit of Fig. 1; Fig. 3 is a vertical section taken on line 3-3 as of dFig. 1, taken through a distilling chamber; a

Fig. 4 is a vertical section taken on linel-l of Fig. 1, taken through a coking chamber. Similar reference characters indicate corre- 4o sponding parts throughout the several views ofthe drawings.

The drawings show a unit adapted-to convert heavy hydrocarbon residuums, as for instance those obtained from an oil refinery into coke, gas

- and some relatively heavy hydrocarbon fractions.

Formerly in thus treating vresiduumsapparatus was used which carried out the process -a batch method and the batch process had the disadvantages commonly associated with all such types 50 of batch units, namely, poor thermal efllciency,.

loss of time, as well as the necessity of employinglarger units per unit of output. Further, with the former batch process, certain cracking v and other chemical processes deposited graph- 55 ite or'tlie like on the interiors of the stills, thereby reducing the coemcient of heat transfer of f the stills. .This resulted because the same surface that was used for distilling the residuums was also used for coking the residuums.

I have overcome the above difllcuities by pro- 5 viding a continuous process and by providing dliferent surfaces for the initial distillation and the final coking.

Referring now more particularly to Fig. 1 the apparatus for carrying out my method, com- 10 prises a charging and distilling chamber A, and

a coking chamber B. The chamber A has a trough-shap'edsteel floor or bottom 3, which slopes downwardly to the coking chamber B. The bottom pan 3 is supported by. I-beams 3. 15 Above and on the sides of the .pan 3 is a wall 1 comprising a heat insulatingbrick wall 3 provided with a steel shell lining l I. Leader pipes l3 conduct vapors rising the chamber A- 'to a main header or manifold 3 which conducts 2o the vapors to a bubble tower l'l. r

"The heavy residuumsto be coked are introduced into chamber A through pipes'and nozzles l9 which lead 011 from a header M (Fig. 3). The

how of the liquid residuums is controlled by and drawn off through the leader pipes l3. The

stock, charged which is not thus immediately vaporized falls to the bottom 3.

A chain arrangement 23, which comprises plates or partitions 25', shaped to the contour. of the floor 3, andwhich are joined together by a suitable'chain linkage 21, is adapted to keep the residuum whichfalls ti) the floor. moving toward the end of the chamber A. The linkage 21 also has wheels 26 which are provided to support the .chainOn a track il. A motor 23 continuously .drives't e chain arrangement.

. The c amber A is heated by gases from the furnaces of the coking chamber. These gases,

by a passage 3|, enter the passage 33, comprisingthe side walls 1, a brick partition 33 and the fioor plate 3 and thereby heat the floor plate 3 to continuously crack and/or distill the. stock which falls thereon. '.The gases leave the'passage it through; a breaching ll and enter a chimney I3.

In the chamber-B the final. coking operation is carried out. The top and side steel lined walls] continue over this chamber. The floor comprises a moving chain grate type .of conveyor ll supported by a number of I-beams 43. The conveyor receives the partially distilled material from the chamber A, and carries it through the chamber B- where it is coked. This chamber is heated by furnaces 45 which burn gas or oil and which heat the top 41 of the furnace to an incandescence.

The grate 4| thus receives the-heat from the in'- candescent surface 41. Nozzles 49 are positioned along the chamber to superheated steam.

- A chamber C is next to the chamber B and is permit the introduction of divided therefrom by a partition 61 which has a tongue ll hanging down. In this chamber super heated steam is-introdueed through nozzles 5| both above and below the grate 4|.

A quenching chamber D is next to the chamber C and in this chamber water is sprayed over the coke on the grate 4| from nozzles 53. A partition 69; with a flap or tongue I3 separates the chambers C and D.

The chamber B, as well as chamber A, is connected by lead pipes 13 with the main header ii.-

The chain grate II is driven by means such as a motor 55; It is to be understood that either the speed of the motors 29 and 55 is made variable or' adjustable driving means is provided between the motors and their respective chains whereby the speed of the chains may be regulated.

- A car 51, placed outside the unit, receives the coke from the grate'll A scraper BI is provided to insure complete'removal of the coke from the grate ll.

A walk 59 is run around the greater part of the unit and enables manual adjustment of the various valves and inspection of the operation. The

, steam lines 49 and 5| are provided with valves for from which it flows into the chamber A- through the nozzles IS, the flow being regulated by thevalves 20. The hot residuum oil on being sprayed into .the chamber A partially cracks, some of the lighter fractions rising in the form of vapor, and the remainder falling to the floor plate 3. The fractions of the oil falling to the floo'r plate a, partially fills the compartments formed by the partition plates 25,-and as the partition plates move-forward under the action of the chain 23,

this oil is moved forward toward the end of the chamber A. Inasmuch as the floor plated is subjected to considerable heat by means of the portion 'of the remaining fractions of the oil which fall to the floor plate is cracked and/or distilled off, so that by the time the oil reaches the end of the floor plate 3 it has become a heavy semi-solid material.

As shown in Fig. l, the nozzles iii are only pro-.

vided over about half the length of the floor plate '3, thereby leaving a substantialarea for the distilling of the oil which falls to the floor plate is. The vapors which are thus distilled off from t e liquid combined with the vapors formed at e initial cracking and vaporization as the stock is sprayed into the chamber A from the nozzles l9, and" pass through the main header iii to the bubble tower l1.

" hot gases passing through the passage 33, a large The semi-solid material which leaves the nozzies 49, the flow of the steam being controlled by suitable valves 60. This steam during the coking operation'helps to dry the material at a lower temperature, at the same time producing a more. porous product. Just before the product or material reaches the quenching chamber D, it passes through a steam chamber in which large quantities of superheated steam isintroduced from the nozzles located above and below the moving grate ll. This introduction of the large 20 quantities of superheated steam substantially removes any volatile compounds which may be left. The coke now passes from chamber 0 into the quenching chamber D at which point cold water from the nozzles 53 is sprayed over the coke to cool it down to a temperature in which; it will not burn when it is extracted from the chamber.

The cold quenching water also serves to cause separation of the coke from the chain grate, so that as it passes out of the. caking chamber and the quenching chamber it freely falls off from the grate. However, any coke which may stick to the grate is removed by the scraper BI.

As hereinbefore pointed out the material while passing through chamber B is heated by means of the flat incandescent arch I! which is raised to an incandescence by means of the furnaces 45 in which gas or.oil or the like is burned. The

hot combustion gases leaving the furnaces 43 passes through a passage 83 (Fig. 2) and enters the passages 3| and .83 to heat the floor plate I.

The vapors from chamber B, which comprise steam and hydrocarbon vapors combine with the vapors from chamber A in the main II and enter the bubble tower together. In the bubble tower the hydrocarbons are fractionated, the lighter ones being taken out at the top and passed through a line 65 to a jet condenser 81, and these lighter fractions are afterwards separated from the water introduced into the Jet condenser 81..

The heavier fractions are either continuously or any hydrocarbon vapors through the steam and water chambers C and D and at the point where the grate ll leaves the chamber B. By thus creating a partial vacuum in chamber B a small amount of air is continuously drawn .in and positiveprevention of any escape of gas is prevented.

It is to be understood that the temperatures of the various chambers, as well as the rate of new of the preheated oil residuum into the cham-- bar A, and of steam into the chamber B and the rate of travel of the conveyors 23 and 4| isregulated to obtain optimum operating conditions, and the values for the various' 'flows and rates is not specified in 'that for different residuums and for different preheats diflerent operating conditions would be required. It is further to be understood that either manual or automatic control may be provided to obtain optimum o ating conditions.

One of the numerous advantages of my process of coking residuums is that it is continuous, and accordingly may be continuously run in cooperation, for instance, with a cracking unit, and in this way a large amount of heat is saved because there is no substantial time lag between the time that they leave the cracking still and enter'the coking plant. Furthermore, by means of continuous operation it is possible to eflfect considerable saving in the usual heat loss in a batch coking operation. A further advantage of the continuous operation is that a smaller unit may be used per unit weight of output, inasmuch as the whole unit is working at all times, and at no time is a portion of the unit inactive.

For purposes of conciseness herein the section A can be referred to as aprimary distilling section, section B a secondary distilling and coking section, section C as a drying section and section D as a cooling or quenching section.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes could be made in carrying out the above constructions, compositions, and

processes without departing from the scope oi the invention, it is intended that all matter con-'- tained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

Apparatus for coking relatively heavy liquid residuums comprising a distilling chamber havwhich the residuums tall asthey enter said coking chamber, and which carries the residuums through the length of the said coking chamber, and furnaces below the residuum-receivingportion of said grate, said furnaces exteriorly heating both of saidchambers, but maintaining said coking chamber at a temperature higher than that of the distilling chamber.

CLIFTON JOHN PRA'IT.

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