US1656617A - Method of distilling coal - Google Patents

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m 392$ msmw B. ZWILLHNGER METHOD OF DISTILLINGCOAL Filed July 14, 1922 5 Sheets-Sheet 1 ATToRNEy I s Sheets-Sheet z INVENTOR M ATTORNEY Jan, 17, 1928. I

B. ZWILLINGER METHOD OF DISTILLING COAL Filed July 14, 1922 n, W MN I Jan, 117 1 928., flfiSfifiW B. ZWHLLENGER METHOD OF DISTILLING COAL Filed July 14, 1922 '3 Sheets-Sheet 3 INVENTOR WM M BY ATTORHE Patented Jan. 17, 1928.

UNITED STATES PATENT OFFICE.

BEBNHARD ZWILLINGER, DECEASED, BY KLARA ZWILLINGER, ADMINISTRATBIZ, NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS, T0 TAR & PETROLEUM PROCESS COMPANY, OF CHICAGO, ILLINOIS, A. CORPORATION .OF ILLINOIS.

METHOD OF DISTILLING COAL.

Application filed July 14, 1922. Serial No. 574,988.

. In modern coke oven practice for the production of metallurgical coke and byproducts great eiiorts have been made in the last decades to carbonize large masses of coal and produce a uniformly carbonized coke with as small an amount of heating gas as possible.

In spite of the progress which has been achieved in some directions, a considerable number of serious defects and disadvantages occur.

The coking of large masses in high, narrow, long chambers has first of all led to considerable complication in the construction and a large' consumption of materials and labor.

In addition to these economic disadvantages the modern by-product oven has other drawbacks which limit its use to the carbonization of certain sorts of coals or mixtures of coals. Such coals for instance which expand during the degasifying process can only be used when mixed in certain proportions with a shrinking coal; otherwise the as wear and tear would be too large and the carbonization might even lead to destruction of the ovens.

Furthermore it is impossible to obtain all the valuable by-products in an unimpaired state, because the coal shrinks away from the heating walls whereby between the coke ends and walls irregular gaps and crevices are formed which serve as paths for the travel of the gases issuing from the coal. as The crude gases beingflsubjected to the catalytic influence of hig y heated brick walls having an area of about 720 square feet and of the incandescent coke ends, it can be readily understood that a part of the byproducts must be destroyed. The formation of these gaps and crevices between the heating walls and the coke ends is the cause of other serious defects in addition to the loss of valuableby-products. Owing to the irregularity of the gaps it is impossible to apply the heat in such a manner so as to roduce a uniformly carbonized coke which is of so great im ortance in blast furnace operationregard ess of what method of heating is applied to these high ovens and of what nature the means are for controlling theheat. The problem of heating the charge becomes still more complex and difiicult for the following reasons: a

The crude gases issuing from the charge as the carbonlzation progresses towards the center are considerably lower in temperature than the source of heat, i. e. the heating wall, and since the gases travel from the center towards the walls, they will take up a certain amount 01 heat from the wall. This retards the progress of heat to the core of the charge. The gases will escape in a superheated condition to the. dome of the oven and to the tar main. The flow of gases takes place on a counter current principle, the gases being generated inside the coal charge at one temperature and flowing towards the source of heat-the heating wallwith a zone of higher temperature. This is disadvantageous to the intended purpose of transferring the heat from the walls to the coal charge. If one considers that the gases represent about 25% more or lessof the entire weight of the coal the retarding action these gases exert upon the 'heat transfer must be large, and as a consequence this also prolongs the coking time. It also necessitates larger condensing surfaces in the condenser of the by-product plant, to cool ofi the higher temperatures due to the fact that the gases leave theoven in a highly heated state. Moreover the resulting decomposition of the gases results in an endothermic reaction which absorbs heat from the heatin wall. Still another difficulty in the equa distribution of heat thru the heating walls is due to the taper. The width of the charge on the pusher side being smaller than on the opposite end of the oven, it will take less time to finish that part of the charge with the result of producing an over or under carbonized coke product.

The irregularities which arise durin the distillation process by the behavior 0% the charge in the high, narrow l y-product oven, are uncontrolable, and for this. reason the modern by-product oven fails to achieve its most important purpose, i. e. the distribution of t e heat in such a manner as to car'- 100 bonize'the coal char e uniformly. The heat ap lication is far :Esom bein accurate.

The great significance of t e by-product oven as an industrial factor justifies a-detailed explanation of the aforesaid defects, and will also assist in understanding my novel process of carbonizin coal, which eliminates the described disa vantages.

My invention is illustrated in the accompanying drawings in which the illustrations show one or more ways for carrying the invention into eifect.

Fig. 1 is a longitudinal section on line 1-1 of Fig. 2.

Fig. 2 is a vertical cross section on line DD of Fig. 1.

Fig. 3 is a vertical section and Fig. 4 is a horizontal section of a modification.

As shown best in Figs. 1 and 2, the heating floor or sole 1 of the oven chamber, sealed from the admission of air, is of considerable width and crowned by a low arch 2 which is rovided wth a number of charging holes 3 or. filling the oven with the material to be coked. The charge to be coked or distilled is heated underneath and the heat supplied from both ends of the. charge. The charge consists of a flat, elongated, horizontal layer of coal which is longer than its breadth, thus providing opposite ends for the layer at each end of the longitudinal axis of the charge.

In the best embodiment of carrying out the method, short narrow longitudinal, independent heating flames are provided, each extending along the sole of the oven and supplying coking heat at a temperature suiticient to coke the char e. The heat supply is subdivided both len t wise and transversely of the layer. Lengt wise a plurality of parallel, equal heating zones are utilized and these are in turn subdivided into groups by a transversedivision wall. The combustion flues 4, 5 are divided by walls 6 forming channels 7, 8 which connect with waste gas main 9, 10. Each combustion flue is provided with a gas supply nozzle 11 which connects by pipe 12 with return gas main 13. Two series of gas su ply nozzles are utilized, one for each oven ront. The air for supporting the combustion is led to air chamber 14, 15, where it is exposed to the radiant heat of the waste mains 9, 10. An. aperture in the arc of the upper air'chamber' con-- nects by short vertical passages 16, in which air shut-oil valve 16 is located, to air superheating channel 17, which runs along underneath the combustion flues 4,. 5 thereby highly preheating the air which escapes by a number of holes 18 impinging on the gas from nozzles substantially at. right angles whereby an intimate gas mixture and a complete combustion is produced, at a temperature suflicient to coke the coal. The oven is also equipped on both sides with combustion flues 19, 20, which are provided also at both fronts of the oven with gas nozzles 21. These side combustion flues may or may not be used, as desired. The air is supplied to the side flues in a similar manner as for burning the gases in the sole flues.

Theside wall flues are low-their height is more or less determined by the thickness of the coal layer which need not exceed 14 to 15 inches. It is obvious that in a sole coke oven havin a width as from 5 to 12 feet, the heat rom the side walls cannot have any influence on the coal layer located in the middle of the oven; in fact the introduction of heating the sides of the charge is in the main to prevent any losses of heat from the sole flues which would occur, if the sole oven would have no side wall heating flues.

On the other hand the temperature in the side walls need never to exceed 900 to 1000 degrees centigrade and at times may be kept lower. In the sole combustion flues the temperature of the coking heat should not fall below 1250 degrees centi ade. It can be readily understood that if in the side wall fines and in the sole flues located next to the side wall flues a temperatureof 1250 degrees centigrade is maintained, narrow strips of coal runnin along the sides of the oven chamber, being subjected from two sides to the influence of heat, would be prematurely carbonized, while the balance of coal would be still in process. Such an occurrence is avoided by keeping the temperature in the side wall combustion flues at about 900 to 1000 degrees centigrade. Each of the flues is supplied with gas and air. The regulating means 22, 23 are easily accessible, and exposed to daylight.

By the division wall 6, which also helps to form the waste gas channels 7, 8 for burned gases, the flue system is divided 'into two equal halves, and as the oven is heated from both fronts the paths of travel for the its combustible gas is very short. It also will be noticed that the entire area of the sole is subjected to the heat of combustible gases, which is a considerable advantage over such methods, where the heat is applied to heating walls partly with combustible gases and partlyv with gases from which the greater part of the heat has been previously absorbed. The operation of the oven is as follows: After the oven is properly heated the covers 24 of the char ing holes are taken off and the lorries moving on rails 25 discharge the coal into the oven. The doors 26 are then removed and the charge is leveled.

After leveling the charge the coal may be compressed by rolling cast 'iron rollers over the charge, in order to obtain a more dense coal, if so desired. The doors are re laced and luted so as to prevent the admission of atmospheric air. The gas nozzles 11 and air valve 16" being opened, combustion takes tion of the charge and noton the sides. The

formation of gaps parallel to the oven floor in Fig. 2 is impossible, for the weight of the charge (which weighs from 5 to 8 tons) will press solidly upon the sole walls and the gases will escape in the direction indicated by arrows in Fig. 2.

The advantages of carbonizing the charge iniformly by my method will be apparent:

(1) The distillation gases are uniformly generated over all parts of the oven floor, due to the heating from both ends, and are conducted thru the cooler zones of the charge, thereby avoiding decomposition of the gases.

(2) With the elimination of the gaps parallel to the oven floor, the heat conducin the high, narrow, chambers, the control and distribution of heat is more uniform and positive in my sole coke oven and by the better utilization of heat, the time for carbonization isreduced.

As previously stated, the charge of coal, subjected to my process, owing to its considerable width and to the comparatively shallow coal layer, may be compressed very eifectively, as by means of a movable roller which is to be applied on the top of the charge for the production of a dense coke.

What I claimed asv new and desire to secure by Letters Patent is:

1. The method of distilling a, flat, elongated, horizontal layer of coal which is thinner than its width and length, while the coal is in a sealed oven chamber, which comprises subjecting the layer to coking heat from beneath from a plurality of parallel, longitudinal, independently regulable flames, air and gas for the flames being supplied from opposite ends of the layer, and collecting the distillates so formed.

2. The method of carbonizing a flat, elon- .gated,'horizontal layer'of coal, while on the sole of a sealed oven chamber which comprises supplying coking heat to the. layer from below at a temperature suflicient to coke'the coal by means of a plurality of independent flames, said flames originating at opposite ends of the layer, and extending along the sole of the oven.

3. The method of distilling coal while on the sole of a sealed oven chamber which comprises spreading a charge of coal in an elongated shallow layer, supplying coking heat, through the bottom and at both ends of the charge sufiicient to coke the coal simultaneously supplying coking heat through: both sides of the charge, and collecting the distillate so formed.

4. The method of distilling coal while on the sole of a sealed oven chamber which KLARA ZWILLINGER, Adwiaistmtrim of the Estate of Bernhard Zwz'lh'nger, deceased.

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