JPH06104832B2 - Method and apparatus for continuous production of coke - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Object of the Invention" The present invention relates to a continuous production method of coke and an apparatus therefor, wherein a coke such as metallurgical coke is continuously and efficiently reduced in heat intensity and elasticity. It is an object of the present invention to provide a method and an apparatus capable of producing a high-strength coke, which is manufactured by a production system having good properties.

Industrial application fields Manufacturing technology for coke for metallurgy.

Conventional technology Coke is widely used for blast furnace charging materials and other metallurgical purposes, castings, fuels, chemicals, etc., and its production has been practiced for a long time. It is usually manufactured in a horizontal chamber type coke oven, which is simply called a coke oven.

That is, this horizontal chamber furnace type coke oven is, for example, as described in pages 183 to 192 of the latest fuel manual (Corona Corp.), and generally has a width of 400 to 500 mm, a height of 4 to 8 m and a depth of 12 to 18 m. Pulverized coal is charged into a carbonization chamber formed of refractory bricks, and heated by heat transfer from combustion chambers formed on both sides of the carbonization chamber to form coke.

That is, in the combustion chamber, the temperature of 1100
Obtaining heat of heat up to 1350 ℃, heat is transferred to the pulverized coal in the carbonization chamber through the refractory brick wall and heated to about 1000 ℃ to form coke. Coal is charged into the carbonization chamber from the furnace top by a coal car, and the obtained coke is extruded by an extruder on the furnace side to a digestion car via a guide car on the opposite side and conveyed to a fire extinguishing facility. In addition, for example, as shown in pages 175 to 181 of the latest fuel handbook, we propose dry coal charging, stamp charging, preheating coal charging, forming coal mixing method, etc. for the purpose of quality improvement and expansion of the range of raw material coal used. In addition, aiming to improve productivity by thinning the carbonization chamber, adopting high thermal conductivity bricks, improving the shape of heat storage bricks, and enlarging or widening the carbonization chamber, as described in Fuel Association Magazine Vol. 63, No. 10, page 889. Is proposed as.

In addition, a continuous molding coke method was developed as described in Fuel Association Magazine Vol. 61, No. 659, pp. 169-177. There is.

Problems to be Solved by the Invention However, the above-mentioned conventional methods all have their own problems and cannot be used as preferred methods.

That is, the above-mentioned general horizontal chamber coke oven has the following disadvantages.

A structure that uses a large amount of expensive refractories, and the construction cost of a coke oven for a steel mill is tens of billions of yen.

 High dry distillation temperature and low productivity.

Since the thermal conductivity of the seats is generally as small as 0.2 to 03 KCal / mh ℃, the carbonization rate progresses in a heat transfer rate-determining state. Also, since the heat of heat from the combustion chamber is conducted through the brick wall, it is not always efficient. Therefore, even if the carbonization temperature is increased in the current furnace width, the carbonization time is considerably long, such as 15 to 20 hours. Therefore, productivity is inevitably low.

A large amount of coking coal, such as 90% or more, is required as the raw material coal used.

 There is no choice but to operate continuously for a long period of time.

That is, since the carbonization chamber is a continuous one that is independent of each chamber through a number of combustion chambers, a coal car, a coke extruder,
Since it is a batch-type work that uses a combination of attached mobile machines such as guide cars and fire extinguishers, it is difficult to automate and save labor.
As described above, long carbonization time is required, and furthermore, the furnace body is almost refractory brick structure and the changeability to temperature change is extremely poor, and it is not possible to make rapid production changes and the production elasticity is poor, and Due to a combination of circumstances such as the difficulty of resuming operation after a long period of suspension, after the start of operation, long-term continuous operation will continue until the life of the furnace expires.

Since there are many opening and closing parts on the furnace top and the furnace side, it is difficult to completely seal the generated gas, and it is difficult to completely take measures against dust generation during carburization and kiln removal. Requires equipment costs.

The above-mentioned technology, which has been proposed mainly for the purpose of expanding the range of coking coal and improving productivity, provides a drastic solution even if some of the problems in the horizontal chamber coke oven as described above can be improved. It is not possible to do so, it requires an extra treatment step, or there is a limit due to the strength of the refractory brick or the strength characteristics of the equipment used, and it is not possible to obtain a sufficient improvement effect.

Even in the continuous forming coke method, the coking coal must be considerably limited.

"Structure of the Invention" Means for Solving the Problems A compacted compact of crushed raw coal is housed in a container in a state of being in close contact and then fired through the container to form a coke on the peripheral surface of the compacted compact. And then take out the peripheral coking compact and convey it in a tunnel furnace while sequentially performing initial, middle and final dry distillation treatments, and a continuous production process of coke, and a coking coal container. And a mechanism for consolidating the raw coal and heating the container containing the raw coal in a compacted state to coke the peripheral surface of the stored raw coal cake. A transport means for receiving the ones taken out from the container in a multi-layered manner at intervals is provided so that the transport means can be passed through a tunnel kiln having each of the initial, middle and final dry distillation means. Continuous production apparatus coke, characterized in that.

Action A compacted compact of a crushed raw coal is contained in a container in a state of being intimately fired, and a coking layer is formed on the peripheral surface of the compacted compact is a blended raw material for subsequent heating coking. Suppresses free expansion during softening and melting of charcoal.

The quality of the coke obtained by suppressing free expansion during softening and melting is improved.

By using the compacted body as described above, the range of use of the raw coal species is expanded and the coke strength is enhanced.

The raw coal cake having a thin coking layer formed on the peripheral surface as described above can be calcined and dried by any method such as indirect, direct and natural methods. Therefore, low temperature carbonization was attempted,
Direct carbonization or natural carbonization reduces the carbonization time and enables more flexible production.

The raw charcoal cake is transported in the tunnel kiln by a trolley or other transportation means to facilitate continuous production.

EXAMPLE The present invention as described above will be further described. In the present invention, coke is produced by the process shown in FIG. That is, roughly classified, pretreatment, formation of surface coke,
These are the steps of dry distillation and cooling productization in the furnace, and each of these steps is described below.

Pre-treatment Several kinds of coking coal are compounded to obtain the desired coke quality, and the coking coal is compacted into a slab shape suitable for dry distillation equipment. It will be accommodated in the condition

Regarding the blending of the above-mentioned raw coal, if necessary, for example,
It is crushed as 20 mesh or less, 100 mesh or less,
At this time, the coal blend may be dried or preheated.

The consolidation may be performed by any method such as pressing, stamping, rollers, etc., but it is consolidated to such an extent that the slab-like shape can be maintained. As a concrete degree of consolidation, the bulk specific gravity is 0.9.
Above, especially 0.95 or more.

The slab-shaped cake 11 obtained as described above is housed in a heat-resistant metal container 10 with the peripheral surface of the cake 11 in close contact with the lid 12 as shown in FIGS. 2 (a) and 2 (b). It

Formation of surface coke In order to obtain good quality coke, suppressing free expansion that occurs during softening and melting of blended coal is a key factor, and the slab-like cake closely packed in the container 10 as described above is The container is directly heated to be softened and melted, and is designed to suppress expansion of coal from the inside due to the pressure resistance of the container, and a thin coke layer is formed on the surface of the slab-shaped cake.

The heating method for forming the coke layer is burner 21.
The container 10 is heated directly from above by heating the container 10 from above and below as shown in FIGS. 2 (c) and (d), and the reaction is carried out after heating appropriately, and the heating is continued by the burner 21 with the lid 12 as the lower surface. The temperature and dry distillation time are selected such that about 10 to 20% of the thickness of the raw coal cake in the container 10 is coked by such heating, and the cake 20 is thinly integrated on the front and back sides and the peripheral side. With the layer coke layer 20a formed, the lid 12 of the container 10 is opened and the cake 20 is taken out as shown in FIG. 2 (e).

The cakes with the coked surface layer 20a taken out are stacked one by one on a receiver such as a heat-resistant metal pallet or stacked on a multi-tiered tray, and these pallets or trays are respectively The heating gas is allowed to flow between the raw material cakes 20 and is placed on the conveying means 34 so as not to interfere with gas generation and release during dry distillation.

The outline of the concrete equipment for the above-mentioned steps is as shown in FIG. 3, and the raw material blended coal pumped by the transportation equipment 14 is received by the hopper 15 as shown in FIG. 3 (a) (b). Is cut from the bottom of the hopper 15 into the formwork 16 and is compacted by the compaction mechanism 17 into a slab-shaped cake 11, which is then loaded into the container 10 into the surface layer coking facility 25. Sent in. In the equipment 25, the process of FIGS. 2 (c) and (d) is the transportation equipment 14 as shown in FIG. 3 (b).
It is clear that this is properly performed in the reversal transfer process of No. 3, and accordingly, the relationship between the heating by the burner 21 in the surface layer coking equipment 25 and the treatment of generated gas at that time is as shown in Fig. 3 (c) (d). The mixed gas 26 is burned by the burner 21, the exhaust gas is heat-exchanged with the combustion air 28 by the preheater 27, and then discharged from the chimney 29 into the atmosphere.

Dry distillation in the furnace The dry distillation furnace basically consists of a tunnel kiln system, and the dry distillation zone has three stages. That is, in the initial stage, as shown in FIG. 4 (a), the mixed gas is burned in the combustion chamber 31 provided in the tunnel kiln 30 and a large amount of tar is contained by indirect heating through the partition wall 32 made of refractory or the like. The gas is generated and guided to the air collection tube 33 to be collected. Surface coke cake 20 mounted on transportation means 34 such as a trolley
In the meantime, they move while being indirectly carbonized and sent to the next middle carbonization stage.

In the middle stage carbonization stage shown in Fig. 4 (b), blast furnace generated gas heated in a hot air stove is blown directly into the furnace from the burner 35, and the cake 20 is subjected to carbonization by direct flame by the heat quantity of the gas. . The generated dry distillation gas is collected as a mixed gas by the collection pipe 36 together with the above-mentioned heating blast furnace gas, and the sensible heat of the mixed gas is used for combustion air in the heat exchanger (the initial heating step described above. It is used for preheating. At this time, the shortage of the heating blast furnace gas can circulate a part of the recovered mixed gas.

The cake 20 on the carriage 34 has undergone a considerable amount of coke after the mid-stage tube drying stage as described above, but it still generates gas rich in hydrogen components, and this is shown in Fig. 4 (c). It is sent to the final dry distillation stage shown. In this final stage of dry distillation, the air for burning the generated gas is introduced into the kiln, and the dry distillation is naturally terminated, and the temperature control at this stage is performed by the amount of introduced air.

Cooling commercialization stage The cart 34 is carried to the extruding section in a state where the red hot coke is loaded, and the red hot coke is discharged by the extruding mechanism and conveyed to the dry fire extinguishing equipment.

Receiving empty surface coke cake taken out of the container 10 in the surface coke formation stage described above through the receiver cooling mechanism equipped with exhaust heat recovery equipment while keeping the empty trays or pallets, etc. Be used for.

The transportation means 34 such as a trolley is also used in a circulating manner.

An outline of the apparatus for carrying out the above steps 1 to 3 in series is as shown in FIG.
A preheating section 41 such as a trolley is placed in front of one end of the furnace, and a facility having a transport facility 14 as shown in FIGS. It is installed across.

The inside of the furnace 40 is formed in series so as to carry out the initial, middle, and final dry distillations of Fig. 4 (a), (b), and (c) in sequence, and an extrusion mechanism is provided at the end of the final dry distillation (c) part. 42, dry fire extinguishing equipment 43, and coke sizing equipment 44 are provided. As described above, the hot-air stove 45 and the like are additionally provided in the medium-term dry distillation area (b).

The required heat distribution in the apparatus as shown in FIG. 5 is generally shown in Table 1 below.

The coke oven gas generated in each of the middle and end stage carbonization processes is once collected as a mixed gas, and the hydrogen-rich end stage carbonization gas is self-consumed. Explaining the concrete coking process result, o = 1.13, MF = 300 and Tin = 28%
Each of the raw coals of 3 was crushed to 80% of 3 mm or less and 100% of 1 mm or less and filled in a metal container of 190 × 235 × 200 mm, and 0.7t / m ³ and 0.9t / m ³ as shown in Table 2 below. ^After press contacting at a density of ³ , dry-distill at a furnace temperature of 900 ° C, select various capping times for the metal containers (shift from the above-mentioned steps), and carry out each carbon-distillation treatment for 4 hours in the whole process (END). The coke strength of the obtained product is as shown in FIGS. 6 (A) and 6 (B). In this case, the removal time and the thickness of the coking layer on the peripheral surface at the time of removal are as shown in Fig. 7, and the strength is improved by forming a thin layer of coke, but the temperature of 900 ° C as described above. Under the conditions, the effect from 60 minutes is large, and the thickness of the surface coking layer at this time is around 10 mm. However, even if the surface coking layer thickness is around 10 mm,
As shown in the figure, the effect of improving the coke strength is shown, and it is clear that sufficiently excellent coke can be obtained.

[Advantages of the Invention] According to the present invention as described above, it is possible to efficiently produce coke in a relatively short time and within a short time, and it is possible to produce high-strength coke. This is an invention which has a great effect industrially because it has elasticity and unmanned operation, and it has the effect of expanding the range of use of the raw material coal species.

[Brief description of drawings]

The drawings show the technical contents of the present invention. FIG. 1 is an explanatory view showing the outline of the process according to the present invention, and FIG. 2 is the loading and unloading of coking coal in the container and surface coke. FIG. 3 is a plan view, a side view and a cross-sectional view of the raw material coal charging / consolidation or surface coking treatment equipment for the vessel, and FIG. 4 is the initial and middle stages in the furnace. FIG. 5 is a plan view showing a general structural relationship of the apparatus of the present invention, FIG. 6 is a chart showing the relationship between the container withdrawing time and the coke strength, and FIG. The figure is a chart showing the relationship between the container take-out time and the coking layer thickness on the peripheral surface of the cake. Therefore, in these drawings, 10 is a container, 11 is a slab cake, 12 is a lid, 14 is a container transportation facility, 15 is a hopper, 16
Is a formwork, 17 is a consolidation mechanism, 20 is a raw material cake, 20a is its surface coking layer, 21 is a burner, 25 is a surface layer coking equipment, 26 is a mixed gas, 27 is a preheater, 28 is combustion air, 29 Is a chimney, 30 is a tunnel kiln, 31 is a combustion chamber, 32 is a partition wall,
33 is an air collecting pipe, 34 is a transportation means such as a truck, 35 is a burner, 36
Is a collection tube, 41 is a preheating section, 42 is an extrusion mechanism, 43 is a dry fire extinguishing equipment, 44 is a coke sizing equipment, 45 is a hot air stove, (a) is initial carbonization, (b) is Mid-stage carbonization, (c) shows the process or zone of end-stage carbonization.

Claims (3)

[Claims] 1. A compacted compact of a crushed raw coal is tightly housed in a container and then fired through the container to form a coke on the peripheral surface of the compacted compact, and then a coke formation of the peripheral surface. A continuous production method of coke, characterized in that each of the initial, middle and final transfer processes is sequentially carried out while the shaped product is taken out and transported in a tunnel furnace. 2. The continuous process for producing coke according to claim 1, wherein the initial dry distillation is carried out by indirect heating, the middle dry distillation is carried out directly, and the final dry distillation is carried out by a natural method. 3. A mechanism for charging the raw coal into a container and consolidating the raw coal, and a mechanism for heating the container containing the raw coal in a compacted state to coke the peripheral surface of the stored raw coal cake. However, the peripheral coke cake container is provided with a conveying means for receiving the one taken out from the container in multiple layers at intervals, and the conveying means is passed through a tunnel kiln having each of the initial, middle and final dry distillation means. A method for continuously producing coke, which is characterized in that