US3536590A - Annular coke oven chamber with rotatable top charging hood and rotatable and movable coke discharge conveyor means - Google Patents

Description

Oct. 27, 1970 KEIJI TSUJIHATA ETAL 3,536,590

ANNULAR COKE OVEN CHAMBER WITH ROTATABLE TOP CHARGING HOOD AND ROTATABLE AND MOVABLE COKE DISCHARGE CONVEYOR MEANS Filed March 14, 1966 5 Sheets-Sheet 1 FIG! FIG. 2

:1 2e- 34 123 4 29 7 35 4 F 27-A MMWW ATTORNEY;

Oct. 27, 1970 KEIJI TSUJIHATA ETAL 3,536,590

ANNULAR COKE OVEN CHAMBER WITH ROTATABLE TOP CHARGING HOOD AND ROTATABLE AND MOVABLE COKE DISCHARGE CONVEYOR MEANS Filed March 14, 1966 3 Sheets-Sheet 2 FIG. 3

INVENTORS BMW WMM ATTORNEYS Oct. 27, 1970 KEIJl TSUJIHATA ETAL 3,536,590

ANNULAR COKE OVEN CHAMBER WITH ROTATABLE TOP CHARGING HOOD AND ROTATABLE AND MOVABLE COKE DISCHARGE CONVEYOR MEANS Filed March 14. 1966 5 Sheets-Sheet 5 F I G. 5

I NVENTOR WMM W ATTORNEYS United States Patent "ice Japan Filed Mar. 14, 1966, Ser. No. 533,901 Claims priority, application Japan, Mar. 15, 1965, 40/ 15,152 Int. Cl. Cb 7/02 US. Cl. 202117 5 Claims ABSTRACT OF THE DISCLOSURE An apparatus for continuous baking of raw materials for producing coke. A fixed annular furnace body having a continuous annular chamber for making raw material has an annular hood rotatably mounted above it in air-tight engagement with the body. A charging device is provided on top of said hood for charging material to be baked. An exhaust gas discharging device is connected adjacent the top of said annular furnace body. A conveying device is provided immediately under the bottom annulus of said furnace body and is rotatable and movable around the furnace body and spirally inclined downwardly in the direction of rotation of the hood from an upper end to a lower end spaced in the direction of the annular furnace body from the upper end, and a material cutting device is provided just beyond the end of the conveying device at the lower end of the inclined conveying device between the lower and upper ends and projecting upwardly from beneath the level of the lower end of the conveying device and rotatable around the furnace body with the conveyor for performing cutting action for cutting material from the bottom of a layer of baked material coming oif said conveying device.

This invention relates to an apparatus for continuously producing coke.

Most gas recovering type carbonization ovens for coke which have heretofore been used as coke producing apparatus are noncontinuous.

Typical of them are the Nittetsu type (Japan), the Otto type and the Koppers type. In such conventional noncontinuous coke ovens (for example a batch coke oven), when a coal charge has been dry-distilled in a carbonizing chamber so as to be converted to coke and th coke has been discharged out of the chamber, because the oven is noncontinuous, the carbonizing chamber will become empty and the temperature in the carbonizing chamber will quickly fall. Further, when the emptied carbonizing chamber is charged with raw material, i.e. coal, the chamber will be filled with the raw material coal at once, and the temperature of the side wall of the carbonizing chamber will quickly fall to about the temperature of the raw material. Therefore, the efficiency of the operation will be greatly reduced.

Furthermore, in such a noncontinuous coke oven, the coal charged into the carbonizing chamber from a charging port begins to be carbonized only by the heat transferred from the carbonizing chamber walls in the traverse direction, and thus coking proceeds toward the center. When the carbonization approaches its final stage, uncarbonized coal remains at the center, extending in the vertical direction, and complete carbonization of the remaining vertical center portion of the coal requires a long time. In this connection, by considering the coal charged into the carbonizing chamber to be a fiat plate free from any chemical change and regarding the thermal conduc- 3,536,590 Patented Oct. 27, 1970 tion as a so-called unsteady one, in which the coal temperature changes from a value 0a, to a higher value 60, the heat conduction can be expressed by Fouriers differential equation as follows:

50/St=a(,9 0/Sx (1) where 0 is the temperature of the solid plate at a spot in question in degrees centigrade, t denotes a lapse of time in hours, x refers to a distance in the heat conducting direction, and a is the thermal diffusivity in m. /hr. and equal to k/Cy, in which stands for the thermal conductivity, C for the specific heat in Kcal./kg.C. and 'y for the density in kg./cu.m.

The solution of the Equation 1 in the case of a semiindefinite solid body, which is indefinitely long in the heat conducting direction, is:

and the solution in the case of a body of definite length is as follows:

1I=Q where V and V0 refer to the heat consumption in KcaL/ kg, s denotes a distance from a carbonizing chamber wall, 00 is the temperature of the carbonizing chamber wall in degrees centigrade, and 0a stands for the temperature of the charged coal in degrees centrigrade. The above formulated heat consumptions show that the nearer to the center (the farther from the heat source) is a given coal portion is located, the slower the carbonization.

As will be understood from the above description, the heat conduction which is directed only from both sides to the center naturally requires a long time (usually 16 to 24 hours), this making the operation markedly inefficient.

The present invention provides a continuously operable coke manufacturing apparatus of a cylindrical upright type which is completely different from the conventional non-continuous coke oven, and seeks mainly to effect a stable and continuous coking operation by carbonizing coal in a thermally economical and always uniform state.

More particularly, this invention is characterized in that a raw material layer is continuously spirally fed into an annular coke oven by means of a rotating raw material charging device so that the cross-section of the raw material body in the chamber is in the form of a plurality of superposed portions and the carbonated layers are drydistilled while the bottom layer is scraped off by means of a rotary scraping device so that the raw material body continuously falls, thus greatly enhancing coke productivity.

As described above, according to the present invention, above a fixed set annular or cylindrical upright coke oven is provide a rotary raw material coal charging device for charging said coke oven with raw material while rotating along said oven, and below said coke oven is provided a rotary coke scraping device for scraping off completely baked coke. Thus, the apparatus of the present invention comprises the rotary charging device and the scraping device provided above and below the annular or cylindrical upright coke oven, respectively.

An object of the present invention is to provide a continuous coke producing apparatus wherein raw material can be continuously fed, dry-distilled and baked into coke and then the coke can be continuously scraped ofl? and conveyed away.

Another object of the present invention is to provide an economical continuous coke producing apparatus wherein coke can be produced at a high thermal efiiciency and a low producing cost.

A further object of the present invention is to provide a continuous coke producing apparatus wherein good coke can be obtained from weak caking coal and automation is easy.

The accompanying drawings illustrate an embodiment of the present invention.

FIG. 1 is a schematic perspective view of a coke producing apparatus according to the present invention.

FIG. 2 is a cross-sectional view on line AA of FIG. 3.

FIG. 3 is a plan view of the same embodiment.

FIG. 4 is a cross-sectional view of an oven body and a hood part of the apparatus of the present invention.

FIG. 5 is a cross-sectional view illustrating a sealing mechanism for the apparatus of the present invention.

FIG. 6 is a detailed view showing the relation between the oven body and a conveying device.

In the present invention, a coal charge is continuously introduced in the form of a layer into a carbonizing chamber by means of a rotary charging device above a fixed cylindrical coke oven which is a feature of the present invention. In such case, the coal charge can be continuously introduced in a pressed and molded form as circular grains, square grains, strips or fragmental strips. If such a pressing and molding system is adopted, Weak caking coal can be easily utilized. The shape of the overall cross-section of the raw material layer introduced is preferably square but can be rectangular, trapezoidal, semicircular or any other shape depending on the expansion, contraction and heat transmission at the time of distillation. The thus introduced coal charge will be heated by radiation and conduction of heat from the brick walls or the walls made of special heatproof cast steel plates defiining the carbonizing chamber which are heated to a red hot state and will begin to be dry-distilled on the upper surface and on both sides. The dry-distillation will begin also on the bottom surface due to the heat transmitted from the partially coked material in the lower layers introduced during previous charging steps as coal and which has been heated by radiation to a red hot state and already dry-distilled to a considerable degree.

On the other hand, the spirally extending and drydistilled charge on the bottom of the party is gradually scraped off by means of the rotary scraping device. Therefore, the charge in the oven will gradually be lowered. The layer deposited at the top corresponds substantially to the thickness of the charge layer scraped off the bottom. The distilled charge on the bottom surface will have cooled to some extent. The gas produced during the drydistillation will be sucked upward by making the pressure in a hood above the oven negative (about 2 mm. water).

The pressure in the hood is properly determined by the operating conditions so that no air will be drawn in through the lower part of the oven and no gas produced in the oven will escape.

In the explanation of this invention, for the sake of brevity, a single annular carbonizing chamber is used. But the number of the carbonizing chambers is not limited to one. A plurality of concentric annular chambers can be used. Usually, when about three chambers are provided, the productivity and economy will be highest.

In the conventional noncontinuous process, the capacity of the coke oven is small and there have been great obstacles to the development of such new techniques as, for example, automation. On the other hand in the present invention, because the coke oven is continuous, the carbonizing conditions in the carbonizing chamber will be very uniform and a stable operation can be achieved. Further, as heat is applied not only from both sides but also from the upper surface and the bottom surface as radiation, the carbonizing time will be greatly reduced, and a remarkable increase of efficiency can be achieved.

The present invention will now be explained more particularly with reference to the drawings. As illustrated in 4 FIGS. 1, 2 and 3, an upper rotary hood 2 is positioned over a fixed annular oven body 7 and a charging hopper 1 including a charging device is mounted therein. Wheels 5 on shafts 6 on the hood 2 support the rotary hood 2 while running on tracks 31 supported on columns 29 positioned on the inside and the outside of oven body 7.

An annular tube 3 for recovering distillation gases extends around furnace body 7 and is supported on columns 10. Gas collecting pipes 12 extend into the annular body from annular tube 3. An annular tube 4 for fuel gases extend around the inside and outside of annular furnace 7 being supported on columns 10 by supports 23. Tube 33 feeds fuel to the inner tube 4 and a similar tube (not shown) feeds the outer tube 4. Conduit pipes 8 extend from annular tubes 4 to burners (not shown) in the annular furnace body 7. A supporting metal piece 9 extends around furnace body 7 and rests on supporting pillar supporting pillars 11 for holding the furnace body.

A rotary conveyor 13 runs around a tail drum 14 and a head drum 15 and extends around the bottom of the annular furnace body 7. A hopper 17 for receiving coke scraped from the bottom layer in the annular furnace body 7 is positioned between drums 14 and 15 and has a conveying pipe 18 connected thereto. A coke scraper 16 is also positioned between drums 14 and 15 and is iven in the direction of rotation of the head drum of the conveyor in the direction of arrow 39. The direction of the travel of the conveyer 13 is indicated by arrow 40. Within the annular furnace body 7 is a continuous annular raw material charging chamber 30, and a continuous annular carbonizing chamber 25 below it defined by carbonizing chamber walls 26. Annular combustion chambers 24 extend through the furnace body 7 on each side of the carbonizing chamber 25.

FIGS. 4-6 show details of the various parts. The continuous charging device for charging the coke oven of the present invention has a raw material charging hopper 1 connected, for example, to a surging hopper.

A sealing means 35 between hood 2 and annular furnace body 7 comprises sealing plate 35A secured to the upper rotary hood 2 and a receiving channel 35B secured to the oven body 7. The outer brick wall 27A of the annular oven body 7 has an outer cover 27B for the bricks. The tracks 31 for Wheels 5 are supported on a support 34 on the outer cover 27B. The structure carrying the rotary scraping conveyer 13 includes wheels 19 on a shaft 12 on the lower member 28 'of a movable carriage 22. Wheels 19 run on rails 32. On the back or inside surface of belt member 13A of conveyer 13 are channel members 13B in which are engaged guide rails 13C mounted on the top member 36 of the carriage 22 and which slide on the guide rails 13C so as to be guided around annular furnace body 7. Reinforcing frame members 37 are provided on the carriage 22. The return run of conveyor belt member 13a is supported on rollers 13D mounted on lower member 28. The upper run of belt member 13A is spirally inclined downwardly from head drum 14 to tail drum 15.

In operation raw material fed into the charging hopper 1 illustrated in FIG. 1 will be gradually fed as the upper rotary hood 2 over the oven body is rotated in the direction indicated by the arrow. The amount of material charge can be adjusted. The fed raw material layer will be deposited in the carbonizing chamber as the top spire of a continuous spiral of material extending in successive spires down through the annular carbonizing chamber, the top spire or layer having a thickness, for example, of about 0.4 meter.

As the carbonizing chamber walls 26 have been heated to a red-hot state by the heat from the combustion chambers 24, the raw material fed into the carbonizing chamber 25 will immediately begin to be dry-distilled. The bottom layer will be scraped off by the rotary scraping device after it has been completely dry-distilled. It is desirable to taper the carbonizing chamber 25 down wardly and outwardly to make it easy for the charge in the carbonizing chamber to descend.

All the gases produced at the time of the dry-distillation will be sucked upward and will be collected in the annular tube 3 through the gas collecting pipe 12. Because the pressure in the oven is made negative, the high temperature dry-distillation gases will rise upward. Therefore, heat will be transmitted from the lower layers to the upper layers and the advantage in the thermal efiiciency will be large.

On the other hand, not only will a newly introduced charge layer receive heat transmitted by the rising gases, as is described above, but also its side surface layers will be heated to a red hot state by radiation from the carbonizing chamber walls 26 and will be dry-distilled to some extent. The top surface layer may already be red hot coke when the upper rotary hood 2 of the oven body brings the charging hopper 1 back to the original charging position, Therefore, the next charge layer introduced onto said surface will receive heat on the bottom thereof and will begin to be preheated, dried and dry-distilled.

As described above, the layers will be dry-distilled by the radiation heat from the carbonizing chamber walls. Needless to say, both sides of the charge will be heated directly from the carbonizing chamber walls 26. Therefore, the dry-distillation of the two sides will progress at a velocity higher than the upper and lower surfaces.

The dry-distillation progresses as described above and the successively deposited charge layers gradually descend to the final lowest layer and the completed coke will be crushed and scraped olf by the rotation of the rotary scraping device 16. The conveyer 13 is driven along beneath the furnace body 7 and supports the bottom layer of material in the furnace body except where scraper 16 is located. The thickness which is scraped ofi can be, for example, 350 mm. but must be selected in relation to the thickness of the charge layer.

It is desirable that the scraping position is somewhat ahead of the charging position in the direction of rotation of the hood. This is to prevent fine vibrations occuring at the time of scraping from being transmitted to the charge layer but is not essential The crushed and scraped coke is discharged out of the oven and is conveyed as required to a cooling place or to a storing place in a plant using the coke.

In the present invention, if the height of the oven is made larger and the number of the spires or layers in the spiral is increased as required the productivity will be able to be greatly increased. Needless to say, if the diameter is made larger, the productivity will also be increased but the thermal efficiency in such case will be lower than in the former.

The recovered gases will be sent to the gas cooler through the dry-distillation gas recovering annular tube 3 and will be treated in the same manner as in a conventional coke oven.

When it is necessary to dissipate gases, it will be possible to dissipate them throughout the gas dissipating tube. The carbonizing chamber walls 26 are heated from the combustion of fuel gases in the combustion chambers 24.

On the other hand, air for combustion is fed through the combustion air pipe, not illustrated in the drawing. Such combustion air can be preheated with a heat-exchanger provided in the oven body. Needless to say, a valve for regulating the amount of air is required so that the air for combustion can mix with the fuel gas.

The waste gas of the combustion in the combustion chamber 24 can be exhausted out of the oven through such heat-exchanger as is described above though not illustrated in the drawing.

The above described heat-exchanger is not essential. Even if it is not provided, the object of the present invention will be able to be well attained.

The present apparatus brings about great advantages (l) the coke oven equipment cost is low relative to the cost of conventional equipment for the same amount of production,

(2) because the system is continuous, the thermal efficiency is high,

(3) only a relatively small space is required for the layout,

(4) because it is possible to continuously feed raw material pressed and molded as required, it is easy to utilize weak caking coal (5) because the amount of production of the gas is always uniform, smoke generation can be easily prevented and (6) automation is easy.

It contributes also to the reduction of costs.

In the present invention, because the raw material charging device is rotatable above the fixed coke oven body and the rotary scraping conveyer is provided in the bottom part of the oven, as compared with such rotary coke ovens previously and developed as a continuous coke producing apparatus of this kind, not only can the power for charging the oven with raw material be greatly reduced but also the oven wall bricks will be less damaged. Further, as the fed coal will be stationary until it is coked, it is possible to obtain coke high in strength. As the fuel feeding system is entirely fixed, there is an advantage that the feeding path is simpler.

What is claimed is:

1. An apparatus for continuous baking of raw materials for producing coke which apparatus comprises, in combination, a fixed annular furnace body having a continuous annular chamber for baking raw material, an an nular hood rotatably mounted above said annular furnace body in airtight engagement with the body, a device on top of said hood for charging material to be baked, a further device connected adjacent the top of said annular furnace body for discharging the exhaust gas produced by baking raw material, a conveying device provided immediately under the bottom annulus of said furnace body and rotatable and movable around the furnace body and being spirally inclined downwardly in the direction of rotation of the hood from an upper end to a lower end spaced in the direction of the annular furnace body from the upper end, and a material cutting device provided just beyond the end of the conveying device at the lower end of the inclined conveying device between the lower and upper ends and projecting upwardly from beneath the level of the lower end of the conveying device and rotatable around the furnace body with the conveyor for performing cutting action for cutting material from the bottom of a layer of baked material coming oif said conveying device.

2. An apparatus as claimed in claim 1 in which said furnace body has annular combustion chambers therein on each side of said annular baking chamber, said combustion chambers being elongated in the vertical direction.

3. An apparatus as claimed in claim 2 in which said baking chamber is downwardly and outwardly tapered.

4. An apparatus as claimed in claim 1 in which said hood has a plurality of wheels thereon, and rails forming part of said apparatus and extending around said annular furnace body on which said wheels run.

5. An apparatus as claimed in claim 1 in which said conveyor device comprises a conveyor belt having an upper run extending along the bottom of the annular furnace body, a carriage on which said conveyor belt is mounted, said carriage having wheels thereon, rails extending around the apparatus beneath the furnace body on which the carriage runs, and guide means on said carriage engaged by the upper run of said belt and guiding said belt along the bottom of said annular furnace body.

(References on following page) 7 8 References Cited 3,302,936 2/1967 Ban 26621 UNITED STATES PATENTS 3,370,937 2/1968 Tsujihata et a1. 266-20 1,698,348 1/1929 Puening 202-262 FOREIGN PATENTS 1,861,876 6/1932 Puening 202-262 r 1,146,045 11/1957 France. 1,908,538 5/1933 Puening 202-115 1,346,891 11/1963 France- 11929132 10/1933 Winzer WILBUR L. BASCOMB, JR., Primary Examiner 2,091,702 8/1937 Daniels 202 115 3,006,816 10/1961 Finney 202-262 10 3,199,850 8/1965 Lee 266-21 202115, 126, 133, 262; 2-01-40; 26621

Images