JP2018168279A - Method of manufacturing coke - Google Patents

Abstract

The present invention provides a method for producing coke, in which coke is produced by coal charging in a method capable of suppressing pulverization of formed coal during carbonization chamber coalification without increasing the amount of binder added.
SOLUTION: A pipe is lowered to the vicinity of the furnace bottom of the carbonization chamber, and after filling the pipe with a coal raw material to a predetermined height, the coal raw material is loaded into the carbonization chamber while pulling up the pipe, and dry-distilled to produce coke. In the method for producing coke, the coal raw material is a mixture of formed coal in the range of 70% by mass to 100% by mass and pulverized coal in the range of 0% by mass to 30% by mass. The coal raw material charging speed and the pipe pulling speed are determined so that the coal raw material that is a mixture and is filled in the pipe has a predetermined height or more.
[Selection] Figure 1

Description

  The present invention relates to a method for producing coke that can maximize the effect of using coal during the production of coke by suppressing powdering of coal in the carbonization chamber.

  In a blast furnace, iron ore and coke are alternately placed in layers in the blast furnace, and the iron ore and coke are heated with high-temperature hot air blown from the tuyere. It produces pig iron by reducing stones. In order to stably operate such a blast furnace, it is effective to improve the air permeability and liquid permeability in the blast furnace. For that purpose, coke with excellent properties such as strength, particle size and post-reaction strength are effective. Use is essential. Among them, the strength of coke is considered to be a particularly important characteristic.

The strength of the coke is normally managed using as an index the drum strength DI ¹⁵⁰ ₁₅ measured by the rotational strength test defined in JIS K 2151. In order to produce high strength coke, it is necessary to use strong caking coal as the main raw material. However, the global increase in demand for steel in recent years has led to an increase in demand for strong caking coal, and in the future it has become necessary to assume the depletion of strong caking coal. Therefore, in the future coke production, technology to produce high-strength coke from lower grade coal such as slightly caking coal and non-caking coal is required.

  One of the technologies for producing high-strength coke from low-grade coal is the coal blending method. This is a process in which part of the coal previously charged in the coke oven is mixed with kneading material such as pitch, kneaded, then pressure-molded to form coal, and this is mixed with pulverized coal and charged into the coke oven. is there. By press molding coal, the packing density increases and the coal particles approach each other, so even low-grade coal with low caking property can be sufficiently bonded during dry distillation. For this reason, high-strength coke can be produced even when low-grade coal is used. However, according to Non-Patent Document 1, in the range where the coal blending ratio is 70% by mass or less, when the coal blending ratio is increased, the coal packing density at the furnace bottom increases. When the packing density of coal at the bottom of the furnace increases, clogging is likely to occur when the produced coke is extruded from the carbonization chamber. For this reason, about 30 mass% is the upper limit for the blending ratio of the forming coal in the coal raw material of the current chamber furnace type coke oven.

  In order to solve this problem, Patent Document 1 discloses a method of charging 100% by mass of coal coal into a chamber furnace type coke oven. By using this method, it is possible to use a large amount of inexpensive coal, the filling density of coal charged into the carbonization chamber is 0.9 in the case of pulverized coal, so that the extrusion load does not increase, and the heat transfer efficiency is improved. It is disclosed that the carbonization time is reduced to 0.7 to 0.8 and the coke productivity is increased 1.1 to 1.3 times.

  In Patent Document 2, coke productivity is improved by setting the proportion of coal coal in the coal raw material to 70 to 95 mass% and the proportion of pulverized coal in the coal raw material to 5 to 30 mass%. It is disclosed that it can be done.

Japanese Patent No. 4505004 Japanese Unexamined Patent Publication No. 2016-27138 Japanese Patent Application Laid-Open No. 7-197028

Okuhara et al., “Coke Circular”, Vol. 25, 1978, p. 312-p. 320.

  According to Patent Document 1, it is possible to produce coke using inexpensive low-grade coal without increasing the extrusion load. However, when the charcoal chamber is charged, the coal is subjected to a drop impact at the furnace bottom, and the coal is crushed and pulverized. Thus, if the coal that contains a large amount of low-grade coal is crushed and pulverized, the effect of blending the coal may not be obtained. In addition, when the coal packing density at the bottom of the furnace increases due to the pulverization of cast coal, the dry distillation time of that portion becomes longer, so the effect of shortening the dry distillation time is reduced.

  In order to suppress the pulverization of the coal, it is conceivable to increase the strength of the coal, but in order to increase the strength of the coal, it is necessary to increase the amount of binder added and the production cost of the coal is increased. To increase. Furthermore, an increase in the gas and tar content during dry distillation by increasing the amount of binder added increases the growth rate of carbon on the surface of the furnace wall refractory, which is undesirable from the standpoint of coke oven furnace management.

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to charge the coal by a method capable of suppressing the pulverization of the formed coal at the time of carbonization chamber charging without increasing the amount of the binder added. It is providing the manufacturing method of the coke which manufactures coke.

The features of the present invention for solving such problems are as follows.
(1) The pipe is lowered to the vicinity of the bottom of the carbonization chamber, and after filling the pipe with a coal raw material to a predetermined height, the coal raw material is charged into the carbonization chamber while the pipe is pulled up, and carbonized. Coke production method for producing coke, wherein the coal raw material is formed coal in a range of 70% by mass or more and 100% by mass or less, pulverized coal in a range of 0% by mass or more and 30% by mass or less, Is a mixed mixture, and determines the coal raw material charging speed and the pipe pulling speed so that the coal raw material filled in the pipe is not less than the predetermined height. Production method

  By carrying out the present invention, it is possible to suppress the pulverization of the formed charcoal during the carbonization of the carbonizing chamber without increasing the amount of the binder added, thereby realizing the production of high strength coke.

It is a figure which shows the outline | summary of the pipe charge used for the manufacturing method of the coke which concerns on this embodiment. It is a perspective view of the test container used in the charcoal test. It is the upper side figure and front view of a forming charcoal. It is a graph which shows the relationship between the pulverization ratio of cast charcoal, and the fall height. It is a cross-sectional schematic diagram which shows the state of the carbonization chamber in each step of the pipe charge of this embodiment. It is the graph which showed the relationship between the filling height of coal raw material, and coal loading time. It is a graph which shows the relationship between coaling time and the height of a pipe lower end. It is a graph which shows the relationship between the pulverization ratio of cast charcoal, and the fall height.

  FIG. 1 is a diagram showing an outline of pipe charge used in the coke manufacturing method according to the present embodiment. First, an outline of a pipe charge used in the coke manufacturing method according to the present embodiment will be described with reference to FIG.

  A coal raw material 6, which is a mixture of powdered coal and cast coal, is loaded into the carbonization chamber 2 from a coal loading hole 4 at the top of the coke oven 1. In the pipe charge of the present embodiment, before the coal raw material 6 is coaled, the pipe 5 is extended from the lower part of the charcoal vehicle 3 and lowered to the vicinity of the furnace bottom through the charring hole 4. The charcoal vehicle 3 fills a pipe 5 with a coal raw material 6. This state is shown in FIG. As a result, the contact between the coal char and the furnace bottom is minimized, and pulverization of the coal char due to a drop collision with the furnace bottom can be suppressed. Moreover, since the upper surface of the coal layer of the pipe 5 can be raised with a small amount of the coal raw material 6 by filling the pipe 5 with the coal raw material 6, the amount of the coal raw material 6 with which the fall height becomes high can be reduced. Thereby, since the quantity of the coal raw material 6 which has a high fall height and receives a big drop impact can be reduced, the pulverization of the formed coal can be further suppressed.

  In the pipe charge of the present embodiment, the pipe 5 is pulled upward when the pipe 5 is filled with the coal raw material 6 to a predetermined height. By pulling up the pipe 5 in this way, a gap is formed between the furnace bottom and the pipe 5, the coal raw material 6 flows between them, and the coal raw material 6 is loaded into the carbonization chamber 2. This state is shown in FIG. 1 (b) and FIG. 1 (c). At this time, the coal loading speed of the coal raw material 6 and the pulling speed of the pipe 5 are set so that the coal raw material 6 filled in the pipe 5 is equal to or higher than a predetermined height. Thereby, since the fall height of the coal raw material 6 can be controlled below a predetermined height, the pulverization ratio of the formed coal can be suppressed below the pulverization ratio corresponding to the drop height.

  The pipe 5 is pulled up, and when the lower end of the pipe 5 reaches the above-mentioned predetermined height or more, the pipe 5 is recovered, and thereafter, the coal raw material 6 is loaded into the carbonization chamber 2 in the same manner as normal coal charging. Charcoal. FIG. 1D shows this state.

  As described above, by using the pipe charge of the present embodiment, pulverization of the coal can be suppressed, so that it is possible to use a lower strength coal. Furthermore, in the case of using the coal raw material 6 in which a large amount of the coal is mixed, since the pulverization of the coal is suppressed by using the pipe charge of the present embodiment, the coal raw material even after being coaled in the carbonization chamber. The ratio of the high charcoal in 6 can be maintained.

  In particular, when the coal raw material 6 in which the coal coal in the range of 70% by mass to 100% by mass and the pulverized coal in the range of 0% by mass to 30% by mass is used is used. By using the pipe charge of the system form, the coal powder is suppressed from being pulverized, and the ratio of the coal coal of the coal raw material 6 coaled in the carbonization chamber is set to 70% by mass or more. Thereby, the carbonization speed of the coal raw material 6 can be improved, and the productivity of coke can be improved. In the present embodiment, the coal is a coal produced by pressure molding after kneading a raw material containing a plurality of brands of coal and a binder that is a binder, and pulverized coal is Single or multiple grades of coal with a particle size of 15 mm or less.

  Next, the relationship between the falling height of the coal and the pulverization ratio of the coal is described. If the fall height of the coal is increased, the drop impact acting on the coal is increased, so that it is predicted that the powdered ratio of the coal is increased. Further, if the strength of the coal is increased, it can withstand the drop impact acting on the coal, so that it is predicted that the powdered ratio of the coal will be reduced. In order to perform this confirmation, a charcoal loading test was performed using a test vessel 10 simulating a general carbonization chamber.

  FIG. 2 is a perspective view of the test container 10 used in the charcoal test. The test container 10 is a rectangular container having a width dimension L1 of 430 mm, a height dimension L2 of 7520 mm, and a length dimension L3 of 3020 mm. An opening 12 is provided on the top surface of the test container 10, and A plurality of windows 14 that can be opened and closed every 1 m are provided. The width dimension L1 and the height dimension L2 of the test vessel 10 are set to be approximately the same as the width of the carbonization chamber of a general coke oven and the drop height of coal when charging coal, respectively. In addition, if the length L3 of the test vessel 10 is too short, the coal loading behavior of the coal raw material 6 may change due to the influence of the side surface of the test vessel 10; The length was such that the influence of 10 side faces did not appear.

  In the charcoal test of the charcoal, the charcoal is loaded from the opening 12 of the test container 10. In the charcoal test, cast charcoal having a length of 49 mm, a width of 49 mm, and a height of 26 mm as shown in FIG. 3 was used. The crushing strength of the coal was adjusted to 1.9 kN, 1.7 kN, 1.1 kN, and 0.7 kN by changing the amount of SOP as a binder. For the crushing strength of the coal, the maximum strength measured by compressing the coal at a compression speed of 1 mm / min using a compression tester was defined as the crushing strength.

After 5.8 t of coal is loaded from the opening 12 until the test container 10 is filled, the coal is collected from the window 14 provided on the side surface. For example, the coal dropped from the lowermost window 14 is dropped. The height was set to 7 m, and the pulverization ratio of the forming charcoal at each drop height was measured. In the present embodiment, among the charcoal collected from the window 14 of the test container 10, it is assumed that the coal that has been sieved on the sieve using a sieve having a mesh opening of 15 mm is a coal, and the powdered ratio of the coal Was calculated using the mass on the sieve, the mass of the charcoal collected from the window 14, and the following equation (1).
Pulverization ratio (mass%) = [1- {mass on sieve (kg) / collected coal mass (kg)}] × 100 (1)

  FIG. 4 is a graph showing the relationship between the pulverization ratio of cast charcoal and the drop height. In FIG. 4, the horizontal axis represents the powdering ratio (mass%), and the vertical axis represents the drop height (m). According to FIG. 4, the pulverization ratio increases as the drop height increases, and the coal with high crushing strength has a low pulverization ratio, and the coal with low crushing strength has a high pulverization ratio. I understand.

  The drop height at which the powdering ratio can be reduced to 20% by mass or less is 8.0 m when the crushing strength is 1.9 kN, 7.4 m when the crushing strength is 1.7 kN, and 5 when the crushing strength is 1.1 kN. When the crushing strength is 0.7 m and 0.5 m, it is 4.2 m. From this, for example, in the case where the fall height of the carbonization chamber 2 is 8.0 m, and the coal powder pulverization ratio target is 20% by mass or less using the coal with a crushing strength of 0.7 kN. It can be seen that the pipe 5 may be filled with 3.8 m of charcoal and the drop height at the time of charcoal should be 4.2 m or less.

  Next, the coal raw material charging speed and the pipe pulling speed will be described. In the pipe charge of this embodiment, the coal loading speed and the pulling speed of the pipe 5 are determined so that the height of the coal raw material 6 filled in the pipe 5 is equal to or higher than the height.

  FIG. 5 is a schematic cross-sectional view showing the state of the carbonization chamber at each stage of the pipe charge of the present embodiment. The example shown in FIG. 5 is a case where the coal raw material 6 is loaded at a constant coal loading speed, and the pulling speed of the pipe 5 is set so that the filling height of the coal raw material 6 filled in the pipe 5 does not change. It is an example of the defined pipe charge.

  FIG. 5 (a) shows a state where the pipe 5 is lowered to the vicinity of the furnace bottom from the coal loading hole 4 of the carbonization chamber 2. In FIG. 5 (a), H is the drop height of the carbonization chamber 2, and D is the length from the charring hole 4 to the lower end of the pipe 5.

FIG. 5B shows a state in which the pipe 5 is filled with the coal raw material 6 to a predetermined height. In FIG. 5 (b), H ₁ is the height of the filled coal raw material 6 (predetermined height). H ₂ is the height of the lower end of the pipe 5. A is the cross-sectional area of the pipe 5, and φ is the diameter of the pipe 5. Α is an angle of repose of the coal raw material 6.

In the state of FIG. 5 (b), the pipe 5 is down to the furnace near the bottom, spaced from the furnace bottom only H _2. For this reason, the coal raw material 6 filled in the pipe 5 spreads from the pipe 5 by a length determined by the angle of repose α and H ₂ . The coal loading of the coal raw material 6 in this state can be calculated by the following equation (2). However, in Formula (2), ρ is the density of the coal raw material 6 and W is the furnace width.

When the pipe 5 is not pulled up, the lower end height H ₂ of the pipe 5 is H-D. Therefore, when the coal loading speed of the coal raw material 6 is V, the time T ₁ until the state shown in FIG. Can be calculated by the following equation (3). A period of 0 ≦ t ≦ T ₁ until the pipe 5 is filled with the coal raw material 6 to the height H ₁ is defined as Phase 1.

After the coal raw material 6 is filled to H _1, raise the pipe 5. The Sosumi rate of coal raw material 6, if the same as the Sosumi speed V described above, the filling rate of the height H ₁ of the coal raw material 6 of the pipe 5, instrumentation coal feedstock 6 is calculated by the following equation (4) the increase per time H ₁ by charcoal can be calculated by the following equation (6) is the sum of the increase per time of an H ₁ by pulling the pipe 5 to be calculated by the following equation (5).

In the example shown in FIG. 5, as the filling height H ₁ of the coal raw material 6 does not change determine the lifting speed of the pipe 5. Therefore, since (6) of the left side becomes 0, the left side is set to 0 (6) Equation indicating the speed of the high H ₂ of the lower end of the pipe 5 from the equation (7) can be calculated. That, is maintained unchanged filling height H ₁ of the coal feed 6 Raising the lower end of the pipe 5 at a rate shown in equation (7).

(7) Solving equation, the time change of the height H ₂ of the lower end of the pipe 5 is (8). Note that in equation (8), _{C 2} is a constant of integration.

In the equation (8), the time for starting the pulling up of the pipe is T ₁ , and the height H ₂ at the lower end of the pipe 5 at this time is HD, so that the integral constant C ₂ is the following equation (9) It can be calculated by

Further, L is inserted from the midpoint between the center of one charging hole adjacent to the pipe and the center of the charging hole into which the pipe is inserted, to the center of the other charging hole adjacent to the pipe and the pipe. For the distance to the midpoint between the center of the charging hole or the charring hole located at the end of the carbonization chamber, the center of the charging hole adjacent to the pipe and the charging hole where the pipe is inserted from the midpoint between the center and the distance to the furnace lid, the coal raw material 6 fills the furnace bottom are the case where height H ₂ of the lower end of the pipe 5 is indicated by the following equation (10) The time T ₂ until the coal raw material 6 fills the furnace bottom can be calculated by the following equation (11). Phase 2 is defined as a period of T ₁ ≦ t ≦ T ₂ from when the pipe 5 is filled with the coal raw material to the height H ₁ until the coal raw material fills the furnace bottom.

After T ₂ elapses, the pipe is pulled up until the height H ₂ of the lower end of the pipe 5 becomes the same height as the filling height H ₁ of the coal raw material 6. If the coal feed rate of the coal raw material is the same as the coal feed rate V described above, the filling height H ₁ of the coal raw material is equal to the H ₁ by the coal feed of the coal raw material 6 calculated by the following equation (12). It can be calculated by the following equation (14) which is the sum of the increase amount per hour and the increase amount of H ₁ by the pipe 5 being pulled up calculated by the following equation (13).

In the example shown in FIG. 5, defining the pull rate as filling height H ₁ of the coal raw material 6 does not change. For this reason, since the left side of the equation (14) is 0, the equation (15) indicating the H ₂ speed can be calculated from the equation (14) with the left side set to 0. That is, at the rate of H ₂ shown in (15), the filling height H ₁ of the coal feed 6 Pulling pipes 5 are maintained unchanged.

When the above equation (15) is solved, the time change of H ₂ becomes the equation (16). Note that in (16), _{C 3} is a constant of integration.

Assuming that the time at which the coal raw material 6 starts to be charged at the bottom of the furnace is t = T ₂ , the height H ₂ of the lower end of the pipe 5 at this time is expressed by the following equation (17). Therefore, the integral constant C ₃ is Is calculated by the following mathematical formula (18).

Moreover, since H ₂ = H ₁ when t = T ₃ , the time T ₃ until the height H ₂ of the lower end of the pipe 5 reaches the filling height H ₁ of the coal raw material 6 is as follows (19 ) Formula. The period of T ₂ ≦ t ≦ T ₃ from when the coal raw material 6 is loaded on the furnace bottom until the height H ₂ of the lower end of the pipe 5 becomes equal to the filling height H ₁ of the coal raw material 6 is Phase 3 To do.

FIG. 6 is a graph showing the relationship between the filling height of the coal raw material 6 and the coal loading time. The filling height in Phase 1 to Phase 3 will be described with reference to FIG. As described above, the pipe charge according to the present embodiment includes Phase 1 to Phase 3. In Phase 1 (0 ≦ t ≦ T ₁ ), the mixing ratio of the formed coal and the pulverized coal, the crushing strength of the formed coal, the target pulverization ratio in the carbonizing chamber 2, and FIG. A filling height H ₁ of the coal raw material 6 to be filled is determined, and the pipe 5 is filled with the coal raw material 6 up to the H ₁ . Thus, in Phase 1, since the coal raw material 6 is filled into the pipe 5, as shown in FIG. 6, the filling height of the coal raw material 6 can be increased faster than the normal coal loading, and the coal raw material 6 can be quickly obtained. The fall height can be lowered.

In Phase 2 (T ₁ ≦ t ≦ T ₂ ), the pulling speed of the pipe 5 (the speed of H ₂ ) calculated by the above equation (7) determined so that the filling height H ₁ of the coal raw material 6 of the pipe 5 does not change. ). For this reason, as shown in FIG. 6, in Phase 2, the filling height of the coal raw material 6 does not change.

In Phase 3 (T ₂ ≦ t ≦ T ₃ ), the pipe is pulled up at the pipe pulling speed (H ₂ speed) calculated by the above equation (15) determined so that the filling height H ₁ of the coal raw material 6 does not change. For this reason, as shown in FIG. 6, in Phase 3, the filling height of the coal raw material 6 does not change. After Phase 3, the pipe 5 is recovered, and thereafter, the coal raw material 6 is charged into the carbonization chamber 2 in the same manner as in normal charging.

  Thus, by charging the coal raw material 6 in the carbonization chamber 2 using the pipe charge of the present embodiment, the filling height of the coal raw material 6 can be increased earlier than the normal coal charging, and thereafter The drop height can be controlled so as to achieve a target pulverization ratio. By controlling the drop height in this way, the pulverization of the coal with low crushing strength can be suppressed, so that the pulverization of the coal when the carbonizing chamber 2 is installed is suppressed without increasing the amount of binder added. it can. The drop height may be controlled by measuring the coal height in the pipe with a known sensor and controlling the pipe pulling speed so that the measured height becomes constant.

  Next, in order to confirm the effect of suppressing the pulverization of the charcoal due to the pipe charge, using the test container 10 shown in FIG. 2, the comparison between the normal charcoal performed in the normal operation and the pipe charge of the present embodiment. The experiment was conducted. The comparative experiment was carried out by adjusting the crushing strength of the coal shown in FIG. 3 to 0.7 kN and loading 5.8 tons of coal from the opening 12 of the test vessel 10.

In the pipe charge of the comparative experiment, a pipe having a maximum length of 6900 mm and a telescope type structure as described in Patent Document 3 was used. By making the pipe a telescopic structure, it is possible to raise the pipe in stages. Filling height H ₁ of pipe charcoal in the pipe, initial molding char filling time (T ₁ ), and time until filling the furnace bottom with charcoal (T ₂ ) so that the falling height of the charcoal is 2 m or 4 m. ), The time (T ₃ ) at which H ₁ and H ₂ are the same was set to the value described in Table 1 below. Further, the height H ₂ of the lower end of the pipe 5, by the time changes as shown in FIG. 7, Sosumi time has recovered pipe after reaching T _3. The coal loading speed was set to 8 tons / min, and all the coals were loaded into the test vessel 10 in about 45 seconds.

  After charcoal was loaded into the test vessel 10, the charcoal was collected from the window 14 provided on the side surface, and the pulverization ratio of the charcoal was measured. In the present embodiment, among all the charcoal collected from the window 14 of the test container 10, pulverization of the charcoal is assumed as the charcoal that has been sieved on the sieve using a sieve having a mesh opening of 15 mm. The ratio was calculated using the above equation (1). The result is shown in FIG.

  FIG. 8 is a graph showing the relationship between the pulverization ratio of cast charcoal and the drop height. In FIG. 8, the horizontal axis represents the powdering ratio (mass%), and the vertical axis represents the drop height (m). As shown in FIG. 8, in normal coal charging (without pipe charge), the powdering ratio was higher as the sampling position was the bottom of the test container 10 and the drop height was higher. On the other hand, in the pipe charge, the pulverization ratio at the bottom of the test vessel 10 was smaller than that in the normal coal charging. By filling the pipe 5 with coal, it is considered that the falling height at the time of coal loading is lowered, and thereby, the pulverization of the coal is suppressed. The reason why the pulverization ratio is high at the bottom of the furnace is thought to be that the drop height did not change from that of normal coal charging until the pipe 5 was filled with coal.

  Thus, since the filling surface of the pipe 5 can be raised with a small amount of the coal raw material 6 by using the pipe charge of the present embodiment, the amount of the coal raw material 6 that has a high drop height and receives a large drop impact can be reduced. Thereby, pulverization of the forming coal at the time of carbonization chamber coalification can be suppressed, without increasing the binder addition amount of forming coal. Moreover, since it becomes possible to use coal with a low crushing strength and a small binder addition amount, it is possible to suppress carbon deposition on the surface of the furnace wall refractory in the carbonization chamber, thereby facilitating furnace body management of the coke oven. .

  Moreover, the target of the ratio of the forming coal in the coal raw material coal-charged in the carbonization chamber is set to, for example, 70% by mass or more and 100% by mass or less, and is set to a filling height that becomes a pulverization ratio that can achieve the ratio of the forming coal. Then, the pipe 5 is pulled up at a pipe pulling speed that is higher than the height. Thereby, generation | occurrence | production of powder | flour can be suppressed, the ratio of the shaping | molding coal of the coal raw material 6 coal-loaded to a carbonization chamber can be 70 mass% or more and 100 mass% or less, and the improvement of coke productivity by shortening of a carbonization speed | rate can be implement | achieved.

In the example shown in FIG. 5, an example in which the pulling speed of the pipe 5 is determined so that the filling height H ₁ of the coal raw material 6 does not change is shown, but the present invention is not limited thereto, and the coal raw material 6 so that the filling height H ₁ or more, may be determined pulling rate of the pipe 5. If the filling height can be set to H ₁ or more, the drop height can be made lower than the case where the pulling speed is set so as not to change the fall height of the coal raw material 6, so that it is clear that the effect of the present invention can be obtained. is there. Moreover, in the example shown in FIG. 5, although the example which made the coal charging speed V constant was shown, it is not restricted to this. The coal charging speed may be changed between Phase 1, Phase 2 and Phase 3, and in this case, the pipe pulling speed corresponding to the coal charging speed may be set.

In Phase 1, the height H ₁ when the coal raw material is filled up to a predetermined height H ₁ is, for example, as shown in FIG. 4, the relationship between the falling height of the used coal and the pulverization ratio. Based on this, it can be determined as a value that is equal to or greater than the difference between the fall height that is the target pulverization ratio and the fall height H of the carbonization chamber. Further, the upper limit of H ₁ is not particularly limited as long as it is between the upper ends of the pipes 5. The recovery of the pipe 5 after Phase 3 may be performed immediately after the completion of Phase 3, or may be gradually performed while charging is continued. In addition, the formed charcoal and the pulverized coal in the present embodiment may include a caking additive that does not act as a binder, powdered coke, oils, plastics, and biomass.

In order to confirm the carbonization rate when the coal was charged with the pipe charge of this embodiment and the coke strength after carbonization, a carbonization test was conducted in an actual furnace. In the dry distillation test, a coal raw material having 100% by mass of coking coal having a crushing strength of 0.7 kN was used. Using the pipe charge of this embodiment, the dry distillation rate and the coke strength were measured for the case where the fall coal was set to 2 m and 4 m, and the case where the coal was loaded with normal coal and the case where the coal was loaded with normal coal, respectively. The carbonization time is the time required until the temperature measured by the thermocouple exceeds 950 ° C by inserting a thermocouple in the center of the width direction, height direction, and length direction of the carbonization chamber. It calculated as a relative value with the carbonization time when coal was charged as 1.00. The coke strength was measured with a drum strength DI ¹⁵⁰ ₁₅ measured by a rotational strength test specified in JIS K 2151. The measurement results are shown in Table 2 below.

  As shown in Table 2, the carbonization time was shorter in the case where the charcoal was loaded using the pipe charge of the present embodiment than in the case where the charcoal was loaded with normal coal. In addition, in the case where coal was loaded using pipe charge, the dry distillation time was shorter when the fall height was 2 m than when the fall height was 4 m.

  In normal coal loading, the coal density is pulverized to increase the packing density at the bottom of the furnace, and the heat transfer rate of the coal raw material 6 at the bottom of the furnace is decreased by the increase in the packing density, thereby increasing the dry distillation time. It is thought. On the other hand, when the pipe charge of the present embodiment is used, pulverization of the forming coal is suppressed, and an increase in the filling density of the furnace bottom is suppressed. For this reason, it is thought that the fall of the heat transfer rate of the coal raw material 6 in a furnace bottom part was suppressed, and the carbonization time became shorter than the case of normal coal loading. Furthermore, by setting the fall height to 2 m, pulverization of the coal is suppressed and the increase in the filling density of the furnace bottom is suppressed as compared with the case where the drop height is set to 4 m. As a result, the dry distillation time is further shortened. It is thought.

  The coke strength was higher when the coal was loaded using the pipe charge of the present embodiment than when the coal was loaded with normal coal. In addition, when the coal was loaded using a pipe charge, the coke strength was higher when the fall height was 2 m than when the fall height was 4 m.

  In normal coal loading, the coking strength of coke after dry distillation is thought to have decreased due to the pulverization of cast coal and the increase in low-grade coal that became powder. On the other hand, when the pipe charge of the present embodiment is used, since the pulverization of the formed coal is suppressed, the amount of low-grade coal that becomes the powder can be reduced, thereby improving the coke strength of the coke after dry distillation. it is conceivable that. In addition, even when pipe charge is used, by setting the fall height to 2 m, it is possible to further suppress the pulverization of the charcoal than when the drop height is set to 4 m. The coke strength was further improved. From these results, it was confirmed that by using the pipe charge of the present embodiment, the coke strength can be improved and the carbonization time can be shortened without increasing the amount of binder added.

DESCRIPTION OF SYMBOLS 1 Coke oven 2 Coking chamber 3 Charcoal vehicle 4 Charging hole 5 Pipe 6 Coal raw material 10 Test vessel 12 Opening 14 Window

Claims (1)

The pipe is lowered to the vicinity of the furnace bottom of the carbonization chamber, and after filling the pipe with a coal raw material to a predetermined height, the coal raw material is loaded into the carbonization chamber while pulling up the pipe, and carbonized to produce coke. A method for producing coke,
The coal raw material is a mixture in which formed coal in a range of 70% by mass to 100% by mass and pulverized coal in a range of 0% by mass to 30% by mass are mixed.
A method for producing coke, wherein a coal loading speed of the coal raw material and a pulling speed of the pipe are determined so that the coal raw material filled in the pipe is equal to or higher than the predetermined height.