JP3567852B2 - Rotary kiln - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a rotary kiln that enables stable operation in a rotary kiln type reduction furnace, an industrial waste incinerator, and the like.
[0002]
[Prior art]
The conventional rotary kiln type furnace, as shown in FIG. 4, puts the processed material 2 into the rotary kiln 1 and places the processed material 2 on the mining side opposite to the moving direction of the processed material 2 indicated by a white arrow in FIG. In general, the processing object heating burner 3 fixedly disposed is configured to heat the processing object 2 moving in the rotary kiln 1.
[0003]
However, in the rotary kiln-type furnace having such a configuration, when the atmosphere temperature on the exhaust side is maintained at the optimum temperature by controlling the combustion of the processing object heating burner 3, the processing object 2 moving in the rotary kiln 1 is controlled. The temperature cannot be maintained at an appropriate temperature, and the treated material 2 gradually adheres to the end of the ore discharge and grows. The deposit 4 changes the flow of exhaust gas in the rotary kiln 1 to change the ambient temperature distribution in the rotary kiln and further promotes the growth of the deposit. Eventually, it becomes impossible to discharge the processed material, and the operation must be stopped, and the attached matter 4 must be removed by human power, mechanical devices, or firing.
[0004]
On the other hand, when the operation is performed with the main purpose of maintaining the temperature of the treated material 2 at an appropriate temperature, the atmospheric temperature on the mining side inevitably increases more than necessary. It damages the internal refractories and makes long-term stable operation impossible.
[0005]
As a means for dealing with such a problem, in a rotary kiln type furnace as shown in FIG. 4 described above, debris is destroyed by firing during operation, but in such a method, a bullet is used. In addition to the high cost of the gun and the labor cost of the shooter, there is a problem that the internal refractory of the rotary kiln may be damaged, and that the components of the product may be deteriorated due to the mixing of gunshot balls with the product.
[0006]
In addition, when the operation start / stop is repeated in a short cycle in order to remove the deposits 4 adhering to the mining side of the rotary kiln, the processing capacity of the rotary kiln decreases and the processing cost only increases. In addition, the refractory in the furnace is subjected to thermal shock due to heating and cooling, thereby shortening the life of the refractory in the furnace.
[0007]
Therefore, in Japanese Patent Application Laid-Open No. 59-16920, as shown in FIG. 5, the treated material heating burner 3 and the rotary kiln burner 5 are fixed to the mining side opposite to the moving direction of the treated material 2 charged into the rotary kiln 1. It is proposed to arrange and heat the atmosphere temperature on the exhaust side of the rotary kiln to an appropriate temperature by using the treated material heating burner 3, and to maintain the temperature of the processed article 2 located on the exhaust side by the rotary kiln burner 5 to the appropriate temperature. Have been.
[0008]
[Problems to be solved by the invention]
However, in the conventional method shown in FIG. 4 and the method proposed in JP-A-59-16920 as shown in FIG. 5, in which the burner is fixedly arranged on the mining side of the rotary kiln, Since the total length of the rotary kiln is as long as several tens to hundreds of meters, it is difficult to optimally control the ambient temperature of the rotary kiln on the side of the material to be treated, leading to a reduction in processing capacity and unstable operation.
[0009]
The rotary kiln of the present invention has been made in view of the above-described problems, and has as its object to provide a rotary kiln that enables stable operation while keeping both the ambient temperature and the temperature of a processed material in the rotary kiln optimal. I have.
[0010]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the rotary kiln of the present invention has a processing object heating burner on the input side of the processing object so that the burner flame flows in parallel with the moving direction of the processing object, and on the discharge side, The rotary kiln burner is arranged so that the burner flame flows in the direction opposite to the moving direction of the processing object. By doing so, the atmosphere temperature in the rotary kiln can be optimally controlled on both the input side and the mining side, and the temperature of the processed material can be maintained at an optimum level. The amount of adhesion can be reduced.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
The rotary kiln of the present invention is a rotary kiln that performs a heat treatment in a process of moving the processed material from the input side to the mining side along the slope while rotating the processed material, wherein, on the input side of the processed material, the burner flame has a moving direction of the processed material. A treated material heating burner is arranged so as to be in a parallel flow, and a burner for a rotary kiln is arranged on the ore-mining side such that a burner flame flows in a direction opposite to the moving direction of the treated material.
[0012]
In the rotary kiln of the present invention, since the processing material heating burner is disposed on the processing material input side and the rotary kiln burner is disposed on the discharging side, the atmosphere temperature in the rotary kiln is optimally controlled on both the charging side and the discharging side. In addition to the above, the temperature of the processed material can be maintained at an optimum level, and the amount of the processed material can be reduced. In addition, since the exhaust gas flow generated by the treated material heating burner is partially shielded by the burner for the rotary kiln, the atmosphere temperature on the exhaust side can be kept high with the same burner fuel amount, and the amount of heat carried by the exhaust gas decreases. Therefore, the burner fuel can be reduced.
[0013]
In the above-described rotary kiln of the present invention, when the treated material heating burner disposed on the input side or the rotary kiln burner disposed on the discharge side is configured to be able to move and swing in three dimensions, the burner is used. Since the position and direction of the flame can be changed arbitrarily, even if the treated material adheres to the input side or the mining side, it can be effectively removed, and more stable long-term continuous operation becomes possible.
[0014]
At this time, an imaging device capable of monitoring the inside of the input side and the mining side of the rotary kiln is provided, and based on the imaging result of this imaging device, the control device controls the position and swing of the processing object heating burner and the rotary kiln burner. Provide a thermometer to control the angle, measure the temperature of the gas, treated material and internal refractory inside the rotary kiln, and a gas analyzer to analyze the gas components in the rotary kiln, and measure these thermometers and gas analyzers. If the control device controls the amount of fuel or combustion air supplied to the processing object heating burner or the rotary kiln burner based on the result, control of the position and direction of the burner flame, or combustion of the burner Control can be performed more optimally.
[0015]
【Example】
Hereinafter, a rotary kiln of the present invention will be described based on an embodiment shown in FIGS.
FIG. 1 is a diagram illustrating a schematic configuration of a rotary kiln of the present invention, FIG. 2 is a diagram of a mining side of FIG. 1 viewed from a plane direction, and FIG. 3 is a diagram illustrating a moving direction of a burner.
[0016]
In FIGS. 1 and 2, reference numeral 11 denotes a processing object heating burner, which is disposed on the charging side of the rotary kiln 1 so that the burner flame 11a flows in parallel with the moving direction of the processing object. Reference numeral 12 denotes a burner for the rotary kiln, which is disposed on the discharge side of the rotary kiln 1 so that the burner flame flows in a direction opposite to the moving direction of the processed material, similarly to the conventional rotary kiln 1.
[0017]
As the shapes of the processing object heating burner 11 and the rotary kiln burner 12, in this embodiment, the processing object heating burner 11 has a linear shape, and the rotary kiln burner 12 has a tip bent shape. The shape of the burner may be appropriately determined depending on the shape of the charging section 17 of the processed material 2 and the shape of the secondary combustion chamber 18 of the exhaust gas, for example, by making the rotary kiln burner 12 a linear shape as shown by an imaginary line. .
[0018]
In the rotary kiln 1 of the present invention, the processing object heating burner 11 is disposed on the input side of the processing object 2 and the rotary kiln burner 12 is disposed on the discharging side, so that the atmosphere temperature in the rotary kiln 1 is on both the charging side and the discharging side. Can be optimally controlled, and the temperature of the processing object 2 can be maintained at an optimum level, so that the amount of the attached matter 4 can be reduced.
[0019]
Further, in the rotary kiln 1 of the present invention, the exhaust gas flow formed by the treated material heating burner 11 is partially shielded by the rotary kiln burner 12, so that the atmosphere temperature on the exhaust side is kept high even with the same burner fuel amount. In addition, the amount of heat carried by the exhaust gas is reduced, so that the burner fuel can be reduced.
[0020]
By the way, the deposits 4 adhering to the input side, the central portion, and the mining side of the rotary kiln 1 may be different from time to time due to a difference between components at the beginning and the end of the operation, the components of the processed material 2, or an atmospheric temperature distribution in the rotary kiln 1. The attachment points are different.
[0021]
Accordingly, in order to effectively remove such deposits 4, for example, the rotary kiln burner 12 disposed on the mining side is moved in the direction of the rotation axis of the rotary kiln 1 (arrow a) as shown by the arrow in FIG. 3) movement in a three-dimensional direction of a vertical axis direction (arrow b) on the vertical plane of the rotation axis (arrow b) and a horizontal axis direction (arrow c) perpendicular to the vertical axis direction, as shown by an arrow d in FIG. By rotating the burner main body or swinging the base end side of the burner main body in the direction shown by arrow e so that the tip side of the rotary kiln burner 12 can be swung, the position of the burner flame 12a and the Since the direction (angle) can be arbitrarily changed, the deposits 4 attached to the tailing side can be effectively removed.
[0022]
At this time, an imaging device, for example, a CCD camera 13 capable of monitoring the inside of the mining side is provided, and while the adhesion state of the deposit 4 is constantly monitored by the CCD camera 13, the burner 12 for the rotary kiln is The position and angle of the rotary kiln burner 12 may be controlled by the control device 14 so that the burner flame 12a is directed to the portion where the deposits 4 are attached most.
[0023]
By the way, in order to improve the processing efficiency of the processing object 2, it is indispensable to maintain the same atmosphere temperature distribution in the rotary kiln 1. It changes remarkably due to a change in the flow, a change in the processing speed of the processing object 2, and the like. Among them, the flow of exhaust gas in the rotary kiln 1 can be dealt with by removing the deposits 4 as described above. Further, when the processing speed is changed, it can be dealt with by changing the amount of burner fuel or combustion air as needed. In the case of a reduction furnace, the inside of the rotary kiln 1 needs to be constantly maintained in a reducing atmosphere. Therefore, in addition to the amount of burner fuel and combustion air, the ratio of fuel to combustion air is adjusted according to the processing speed. It can be dealt with by changing it as needed.
[0024]
Therefore, for example, a radiation thermometer 15 for measuring the temperature of the gas, the processed material and the inner refractory inside the rotary kiln 1 and a gas analyzer 16 for analyzing gas components in the rotary kiln 1 are provided. The position and direction of the burner flame are controlled by controlling the amount and ratio of fuel and combustion air supplied to the processing object heating burner 11 and the rotary kiln burner 12 by the control device 14 based on the measurement result of the analyzer 16. Alternatively, the burner combustion control can be performed more optimally, and the ambient temperature distribution in the rotary kiln 1 can be maintained under the same conditions.
[0025]
Since the melting point of the deposit 4 when the steelmaking dust is melt-reduced is as high as 1600 ° C., the temperature of the burner flames 11 a and 12 a of the treated material heating burner 11 and the rotary kiln burner 12 is required to be about 2000 ° C. Therefore, in such a case, if the gas generated from the coke oven in the steel mill and pure oxygen are used instead of the combustion air as the burner fuel, the combustion efficiency is increased and the temperature of the burner flames 11a and 12a is increased. It is also possible to increase the temperature and to blow off the deposit 4 by the burner flame 12a.
[0026]
In the present embodiment, the CCD camera 13 is shown as the imaging device, and the radiation thermometer 15 is shown as the thermometer. However, other imaging devices and thermometers may be used as long as they have the same function. Needless to say, it's good.
[0027]
Although the detailed structure of the moving mechanism of the rotary kiln burner 12 is omitted in this embodiment, a known mechanism such as an arm or a link mechanism may be used.
[0028]
Although the description is omitted in the present embodiment, the workpiece heating burner 11 is indicated by an arrow in FIG. 3 based on an imaging result by the CCD camera 19 for monitoring the inside of the input side shown by an imaginary line in FIG. Alternatively, the position of the burner flame 11a may be controlled so as to be able to swing in the three-dimensional direction.
[0029]
【The invention's effect】
As described above, according to the rotary kiln of the present invention, the atmosphere temperature in the rotary kiln can be optimally controlled on both the input side and the mining side, and the temperature of the processed material can be kept optimal. As a result, it is possible to reduce the amount of the adhered processed material. In addition, since the exhaust gas flow generated by the treated material heating burner is partially shielded by the burner for the rotary kiln, the atmosphere temperature on the exhaust side can be kept high with the same burner fuel amount, and the amount of heat carried by the exhaust gas decreases. Therefore, it is possible to solve all the problems of the conventional rotary kiln, such as a reduction in burner fuel.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a schematic configuration of a rotary kiln of the present invention.
FIG. 2 is a diagram of the mining side of FIG. 1 viewed from a plane direction.
FIG. 3 is a diagram illustrating a moving direction of a burner.
FIG. 4 is a diagram illustrating a schematic configuration of a conventional rotary kiln.
FIG. 5 is a diagram illustrating a schematic configuration of a rotary kiln proposed in Japanese Patent Application Laid-Open No. Sho 59-16920.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rotary kiln 2 Processing object 4 Deposits 11 Processing object heating burner 11a Burner flame 12 Burner for rotary kiln 13 CCD camera 14 Control device 15 Radiation thermometer 16 Gas analyzer 19 CCD camera

Claims (9)

In a rotary kiln that performs heat treatment in the process of moving the processed material from the input side to the mining side along the slope while rotating, the burner flame flows parallel to the moving direction of the processed material on the input side of the processed material. A rotary kiln wherein a burner for a rotary kiln is disposed on a treated material heating burner and on a discharge side such that a burner flame flows in a direction opposite to a moving direction of the treated material. 2. The rotary kiln according to claim 1, wherein the treated material heating burner disposed on the input side is fixed, and the rotary kiln burner disposed on the mining side is configured to be able to move and swing in three dimensions. . 3. The rotary kiln according to claim 2, wherein the workpiece heating burner disposed on the loading side is configured to be able to move and swing in a three-dimensional direction. 2. The rotary kiln according to claim 1, wherein the workpiece heating burner disposed on the charging side can be moved and swung in three dimensions and the rotary kiln burner disposed on the mining side is fixed. 3. An image pickup device capable of monitoring the inside of a rotary kiln on the mining side, and a control device controlling a position and a swing angle of a burner for the rotary kiln based on an image pickup result of the image pickup device. 3. The rotary kiln according to 3. 4. An image pickup device capable of monitoring the inside of the input side of the rotary kiln, and a control device for controlling a position and a swing angle of the workpiece heating burner based on an image pickup result of the image pickup device. 4. The rotary kiln according to 4. An image pickup device capable of monitoring the inside of the input side and the mining side in the rotary kiln, and a control device for controlling the position and the swing angle of the burner for the workpiece heating and the burner for the rotary kiln based on the image pickup results of these image pickup devices are provided. The rotary kiln according to claim 3, wherein: A thermometer for measuring the temperature of the gas, treated material and refractory inside the rotary kiln, a gas analyzer for analyzing gas components in the rotary kiln, and a burner for the rotary kiln based on the measurement results of the thermometer and the gas analyzer. The rotary kiln according to any one of claims 1 to 7, further comprising a control device for controlling an amount or a ratio of a fuel or combustion air to be generated. Gas in the rotary kiln, processed material, a thermometer that measures the temperature of the inner refractory, a gas analyzer that analyzes gas components in the rotary kiln, and a processed material heating burner based on the measurement results of the thermometer and the gas analyzer The rotary kiln according to any one of claims 1 to 8, further comprising a control device for controlling an amount and a ratio of supplied fuel and combustion air.

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