US2091702A - Production of low temperature coke - Google Patents

Description

1937. J; DANIELS PRODUCTION OF LOW TEMPERATURE COKE Filed Feb. 20, 1934 3 Sheets-Sheet 1 Aug. 31, 1937. J. DANIELS 2,091,702

PRODUCTION OF LOW TEMPERATURE COKE Filed Feb. 20, 1934 3 Sheets-Sheet 2 Patented Aug. 31,1931

PATENT OFFICE rnonuc'rron or Low TEMPERATURE COKE r Joseph Daniela, Essen, Germany, assignor, by mesne assignments, ,to Koppers Company, a corporation of Delaware Application February 20, 1934, Serial No. 712,193 In Germany February 20, 1933 2 Claims. wl. 202-98) My invention relates to the productionof coke from caking coal, more particularly pit coal, at

low temperatures, and has particular reference to'the production of low temperature coke from i coal, in which the coal during the carbonization is in a; state of rest.

By the term low temperature carbonization of fuel is implied in general dry heating of the fuel for the purpose of carbonization, that means, the fuel is heated in an air-tight closed container,

the temperature of the fuel during the carbonization, as a rule, substantially not exceeding about 650, centigrade. a coke is obtained which is comparatively rich in liquid constituents, is highly reactive and has a comparatively low ignition point. Low temperature cokeor semi-coke burns practically without smoke, in contradistinction to rough coal. It is thus a fuel which is particularly well suited for household purposes as it can be burned as well in the usual room stoves as also in kitchen ranges and open fireplaces.- Also the use of semi-coke under the boilers of central heating plants affords great advantages because of the fact that a fire of semi-coke can be regulated within much wider limits than a fire of the known high temperature coke or blast furnace coke.

Furthermore, low temperature carbonization is of great importance, aside from the production of a high grade smokeless fuel, in that in carbonization of this type a number of high grade byproducts are obtained which are burned away uselessly in the combustion of the rough coal, viz. in the first place the light hydrocarbons that form an excellent fuel for internal combustion engines.

In general, low temperature carbonization is .carried on in retorts or chambers made from cast iron or any other suitable heat-resisting metal or metal alloy. Retorts of this kind are employed with advantage for low temperature carbonization, because the difierence of temperature between the heated retort wall and the coal is comparatively small, whereby also a comparatively slow heat flow is caused. If retorts made from ceramic material are usedlike those employed in the usual high temperature carboniza- 'tion, a comparatively high heat resistance would exist between the flame or. the heating gases which serve to heat the retort and would prevent an advantageous rapid heating of the coal to be 5 erto, has not been employed in the industry on a By a carbonization of this'lrind large scale, is substantially the following: At the carbonization temperatures under consideration for low temperature carbonization the coke produced practically does not yet shrink. The coke thus completely fills the space of the retorts or chambers and therefore can be removed therefrom only difficultly. The low temperature coke cake cannot be pushed from the retorts, as it is usual in the high temperature carbonization.

Now the object of my invention is to provide improvements in the appliances serving for the production of low temperature coke, which enable the low temperaturecoke to be removed in a simple and easy manner from the retorts.

Another object of my invention is to provide improvements in the heating appliances of low temperature retorts, by which a uniform heating effect on the retorts without overheating the walls of the latter is obtained.

A further object of my invention is to provide improvements in ovens or apparatus for the production of low temperature coke which afl'ord an easy attendance of the appliance and an economically satisfactory operation.

Finally, my invention provides improvements in theconstruction of the iron retorts or chambers seil'gving for the production of low temperature co e.

Further incidental objects of my invention will be disclosed in describing in detail a practical embodiment of my present invention by way of example, with reference to the accompanying drawings.

In the drawings Figure 1 is a top view of an annular tunnel oven designed according to the invention,

Figure 2 is a vertical section and side view on line IIII of Figure 1,

Figure 3 shows on enlarged scale the top view of the superstructure of one of the coking cars of the oven according to Figure 1,

Figure 4 is a vertical cross section of the oven represented in Figure 1, on enlarged scale, and

Figure 5 is a vertical cross section of a modified form of tunnel oven.

In the oven illustrated in Figure 1 the coking of the coal to be treated takes place in four curved chambers I which are arranged side by side and form a ring. The chambers i consist of refractory brickwork 2. On their ends they are pro vlded with apertures that can be closed by doors 3. The latter can be lifted by means of lifting devices 4 mounted on the cover of the oven, the respective apertures then being open. The brickwork of the chambers I is held together by iron anchor bars 5.

Between each two chambers I is provided a free space 6 of such a width that the charge of a coking car to be described hereinafter can be lodged in this free space. The spaces 6 serve to fill with coal the coking cars of the oven and to remove the coke produced from the cars.

As it will be seen in Figure 4, two circles of stationary supporting rollers I are provided on the floor of the oven chambers I on which rollers rest a series of coking cars 9 by means of rails 8. The cars 9 are provided with a bottom channel III which has a lateral aperture II and several top apertures I2.

Each coking car 9 has mounted on it a plurality of boxes I3 which preferably consist of several parts interconnected by screw bolts I4. Each box has two walls extending on the entire width of the car and interconnected .by partitions I5, see Figure 3, in such a manner that each box I3 has an approximately sector-shaped cross section. The intermediate spaces formed by the vertical partitions I5 and the longitudinalwalls of the boxes I3 are open on top and bottom. They serve to uniformly distribute the hot gases required for heating the coal on the entire surface of the boxes I3. These heating gases are drawn off through the floor channel I0.in a manner described hereinafter. In order to uniformly draw off the gases from the individual hollow spaces of the boxes I3, the lower apertures of the intermediate spaces of the boxes, which lie immediately above the apertures I2, are narrowed,

as denoted by I6.

The individual boxes I3 are arranged on th respective car 9 with a suitable mutual distance, so that intermediate spaces I1 are formed which serve to receive the coal to be coked. The spaces I1 are closed on their lower end by the bottom of the car, while on the sides they are closed by removable cover plates I8 which are held in position by guides I9 fixed to the, boxes I3. On top the spaces H are open so that the gases produced during the distillation of the coal canescape.

The coal is charged into the car standing in the respective space 6 of the oven by means of a charging device 20 fitted with several spouts 2| arranged on a superstructure 22 above the spaces 6. The spouts 2| are constructed in such a manner that each one of them is situated above one of the spaces ll of the cars 9 which spaces are intended to receive the coal.

The coke produced in the spaces I! of the coking cars is withdrawn therefrom by means of a pushing device 24 comprising a plurality of pusher bars 23, one particular pushing device being provided for each of the spaces 5 of the 0 oven, see Figure 1. The devices 24 are situated on the inner side of the annular oven brickwork. The pushing devices 24 are of a construction which in principle is similar to the known pushing devices of horizontal chamber ovens for the 5 production of gas and coke. They push the coke, after removal of the cover plate I8 of the coking car from the intermediate spaces I'I onto a wharf 25 and from there into coke cars 26.

The coal charged between the boxes I3 and 7 introduced in the oven on the coking car 9 is heated by gases circulating through the chambers I. The hot gases are supplied to an annular distribution top channel 28, Figure 4, and enter the chambers I through apertures 29. The gases 75 then flow through the hollow spaces of the boxes I3 and thence through the apertures I2 to the floor channel'IO of the coking cars 9. A series of apertures 30 are provided in the outer wall of each chamber I exactly opposite to the lateral apertures of the coking cars 9 when the latter are within the chamber. The apertures 30 are fitted with longitudinal tubes 3| that can be shifted from outside by means of setting levers 32, Figure 4. The tubes 3| serve to tightly connect the apertures I I of the cars 9 with the apertures 30 of the oven wall. Before the cars 9 are to be shifted, the levers 32 are turned over, whereby the tubes 3I are withdrawn from the apertures I I and the cars 9 are free to be moved.

The apertures 30 are attached through the intermediary of bent pipes 34 fitted with dampers rality of chambers 38 of refractory brickwork 39.

these regenerators are arranged channels 46, 41

that lead to bent pipes 48 situated outside the oven and by channels 49 in communication with the waste gas collecting channel 50.

Furthermore, a gas feeding conduit 5| extends along the heating appliances from which conduit a pipe 53 governed by a throttle valve 52 leads to each of the legs ofthe U-shaped heating pipes 40. The burners are provided on the inner end of the pipes 53, one of these burners being situated below the one leg of the U-shaped pipe 40 while the other burner is below the other leg thereof, see Figure 4. The gas nozzles of these burners are denoted by 54 and 55. A peep hole 56 arranged at the level of the nozzles'allows inspection of the burners during service.

The U-shaped heating pipes 40 are heated in the following manner:

The bent pipe 48 belonging to the one regenerator 44 connected with the respective pipe 40, of the couple of regenerators is set in such a manner that air can enter the regenerator 44. The air is heated by the refractory chequer work 43 of the latter and flows through the connecting channel 4I into the lower part of the heating pipe 40. Simultaneously the throttle valve 52 of the gas feeding conduit is regulated in such a manner that gas is fed to the burner nozzle 54. Gas and air now burn below the lefthand leg of pipe 40, Figure 4. The hot gases of combustion rise in the pipe 40 and descend in the other leg thereof. Thereupon through the channel 42 they enter the regenerator 45, where they give off part of. their heat to the chequer work, and finally escape through the floor channel 46 of regenerator 45 and the bent pipe connected thereto, and situated behindthe bent pipe denoted in Figure 4 by 48, into the waste gas channel 50.

As soon as the temperature of the chequer work in the regenerator 44 has lowered to such an extent that the air of combustion is not longer preheated therein as required, the direction of flow of the media is reversed, that means, cold air of combustion is fed to regenerator and heating gas to the nozzle 55, and the waste gases are drawn off through regenerator N. I

As to be seen in Figure 1, the heating appliances arranged on the outer sidesof the coking chambers l are. designed in such a manner, that two heating pipes All exist in each compartment.

formed by partitions- 51f." j The latter are provided with apertures 58'alternatively on top and;

bottom, so thatall heating"chambers ia'are' in communication with one;- another.}. Asf willbe the distribution channel 28 into the adjacent coking chamber I. I d I In the event that the temperature of. the gas flowing through the bent pipe 21 isfnot high enough, the'temperature can ibeyraised by auxiliary burners 58' to which'fgas isied-lthrough' a pipe 5'9 and air through a pipeili, gure-4. The hot gases escaping fro'rn the-.auxiliary-burners 58' admix to thegas in the top channel 28.

The gases produced by the coking of the coal admix to the heating gas circulated in ,the cycle described above through the coking chambers and the adjacent heating appliances.- Consequently, the volume of the circulatingquantity.

of gas permanently is increased. In order-to keep 'this gas volume constant, part. of the gas: is withdrawn permanently from the circulationand conveyed to a usual washing and cooling apparatus, not shown. In this apparatusthe con densable constitutents are removed from the gas.

Part of the purified gas serves to heat the heat ing pipes 40 and to feed the auxiliary burners 58. The gas in excess may be used for other,

5 purposes, such as lightning.

Owing to the gases being cooled'in the gas main 35, a small quantity of liquidhydrocarbons sometimes collects therein which must be drained In order to maintain as I from time to time. 50 small as possible the condensation of gas-constituents in the several pipe parts outside-the ure 4.

ceramic material, as described above, they may consist of heat-resistant cast iron or of any other suitable material. Furthermore, it may be of advantage under certain circumstances, to 60 provide several double bent pipes 21 on the oven cover in lieu of one sole pipe, in order to maintain varying temperatures on various places of the oven chambers.

As it will be seen in Figure 1, the oven chain- 65 hers I are of such a size, that four coking cars 9 with their boxes l3 can be lodged therein. The cars 9 are fitted on their front sides with buiierlike extensions that can be interconnected in any suitable manner (not shown).

The oven illustrated in Figure 1 is operated substantially as follows:

The coking cars 9 successively are charged with coal and are run with appropriate mutual distance into the chambers I. As soon as the 75 fourth car 9 enters the respective chamber l,

of the pushing direction. been pushed, the boxes' l3 again are reset :to nor-.- mal positionand the coverplates l8 inserted. The" carfis then again ready for being charged with fresh coal. This 3done, the'car is runinto t a hot car 9 is withd' wn on the other end of the chamber. ,The tem erature in the chambers l and the period of time 'the cars remain inthe chambers is so determined that during the passage of the cars the coal therein is converted to coke. As soon as the'charge of the car situated onthe one door 3 of the chamber has been coked,

thetwo doors 3 of the chamber are lifted and the 'series of cars upon entering a freshly charged r carjisur'ged forward-so far that the freshly "chargedcar arrives inthe chamber and the car ready for] discharge arrives on the discharge .-,'place- B.. This; (can is then uncoupled and the doc s 3 :are closed. Thereu'ponthe 'sfhiftable tubes .31, which ,as above described 5 previous to;

shiiting1theseriesof cars,'havefbeen withdrawn, 'are shifted inwardsku'ntil the apertures ii of -lc'ars 9 are ft'ightly connected} 'hne therpro'duction r coke" is continued" n the coking chambers-fl, the [coke contained' inthe. pushed car that-fi's standing ongthe discharge place 6,is pushed. The pushing-ofthecoke-cue v closed between the mawmu'ar boxes: [3 is facili-p 1 tatedby "the-space existing betweenthe latterslightly enlarging'outwardly and by the boxes I3.

I being shiftable on the carsfl fil u u ing of the coke they can'give way transversely the next "following. cokin'g'chamber. The direction of runof the cars thus permanently remains the same. Within allilcoking chambers] the freshly charged} cars' 9 fare supplied on one end and cars containing finished coke are withdrawn .onthe other'jerid, The motion of-the-cars-maybe. carried on. in

After the 1 cokej has'T;

any-suitabie'manner; 1111 the'oven illustrated they are moved by me'ans'of a'wire cable disposed belov'v the carsand actuated by 'a acapstan situatedonone of the'jdischarge places. 6.. Thefeable preferably is endless and is putwithjseveral {coils aroundthe' drum of the-capsta'm- The; cars are detachably fixed to the cable in'iariy suitable manner, for example by ciampingjdevicesknown in the art. The meansifoi moving the cars thus substantially are the same-as in the usual cable railways, as used in industrialWOrks, collieries, oven brickwork, these outer pipe parts, are en-- veloped by heat-insulating material 6i; see Fig coking plants and the likel '-Figure 5 shows a modified form of the coking cars. In this modification-aseries of apertures Instead of making the heating pipes 4'0 from rounded by cylindrical supporting tubes 14 provided with a central opening 15- and lateral apertures 16. On the supporting tubes 14 are mounted coaxial pipes l1, 18 which slightly taper vupwardly. The inner pipes I8 carry outer lugs 19 that serve to hold the tubes 18 at a certain distance apart from the outer pipe TI.

The coal to becoked is charged into the annular space existing between the pipes l1, 18. In order to discharge the coke, the outer pipe I1 is extracted on the eyes 80 and the inner pipe l8 is lowered, whereupon the coke drops from the latter.

The coking pipes ll, 18 are uniformly distributed on the entire surface of the car II. By the use of these pipes instead of the boxes l-3 of the first embodiment the advantage is afforded that the coal can be coked in very thin layers and is heated from all sides. Thereby a comparatively high coking speed' is obtained and therewith also a higher yield of the oven plant.

Except the charging and discharging of the 5 coal containers, the operation of this modified oven according to Figure 5 is exactly the same as that of the first-described embodiment.

What I claim is:- r 1. Apparatus for production of reactive, easily inflammable coke (semi-coke) by low temperature carbonization of fuel, comprising: a tunnel oven comprising a plurality of tunnel oven sectors arranged to form a circle with spaces between the sectors for charging and discharging; v 5 a continuous endless circular trackway extending through all of said ovens; transporting cars adapted to run on said trackway; means for interengaging the cars for moving them in succession through each oven sector and through all of the oven sectors in series; a series of metallic boxes adapted to be set and remain set in spaced side-by-side self-standing relationship on a base support therefor on the cars so as to form the heating walls of a group of coking chambers alternating in position with the heating walls for coking coal in thin layers on said cars; said boxes being movably mounted at their baseson the cars so that they may be readily spread from each other on the cars for discharge of coke and may be re-set on their base supports therefor on the cars for another series of coal charges in thin layers by merely resetting them up in self-standing relationship; said boxes being flued and having inlet and outlet openings for flow of heating gases through the flues of the boxes; said cars being provided on their bottoms with base supporting means for supporting the bases of the boxes in self-standing relationship and with a channel communicating with the flues of the boxes through flue openings therefor; each channel having a port; a conduit outside said' oven sectors for circulation of heating gases; stationary ducts for communicably connecting said conduit with the channels in the bottoms of the cars; longitudinally shiftable sleeves mounted in the walls of the oven sectors and each adapted to telescopically connect the port of the channel of a car with one of the stationary ducts of the outside conduit; means for operating the sleeves to connect and disconnect them as aforesaid; a blower in communication with said outside conduit and with another conduit also communieating with said oven sectors; and means for heating gases connected with one of said conduits to provide hot heating gases for said conduits.

2. Apparatus for production of a reactive, easily inflammable coke (semi-coke) by low temperature carbonization of fuel, comprising: a plurality of curved tunnel ovens arranged in series as sectors of a circle, adjacent ovens in the series being spaced from each other to provide between the ends of the adjacent ovens accessible stations for discharging coke and recharging fuel for coking; a continuous endless circular track extending through all of said ovens; transporting cars adapted to run on said track and having base supporting means for cooperation with the bases of the walls of coking receptacles so as to support the same in self-standing relationship on the cars; means for interengaging the cars for moving the cars in succession through each oven and through all of said ovens in series; coking receptacles comprising walls adapted to be set and remain set in laterally spaced self-standing relationship relative to each other on the base supporting means therefor on the cars so as to form a group of coking chambers for coking coal in thin layers on said cars, the walls forming the coking receptacles being separable from each other and having their bases mounted on the cars for separating the walls forming the receptacles from each other and from the cars for dis charge of finished coke; the walls of the receptacles being also adapted for being covered on one side by the fuel and to be traversed by heating gases on the other side to coke the fuel; means for flowing heating gases through each of said ovens for low temperature coking as aforesaid; and means at each of said stations for discharging said receptacles after leaving one sector and for reloading them before re-entering the next sector.

JOSEPH DANIELS.

Images