JP2001262156A - Method for feeding blended coal to humidity control installation of coal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for suppressing the change of water contents of fed coal, caused by the retardation of a humidity-controlling operation based on the difference of the shapes when feeding the blended coal having different water contents to the humidity-controlling installation of the coal. SOLUTION: This method for feeding the blended coal to the humidity- controlling installation comprises determining the amount of the blended coal to be cut out from a wet coal hopper according to each of the water contents of the blended coals before and after the switching when plural kinds of the blended coal having different water contents are used by switching.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for supplying blended coal necessary for humidity control of coal charged in a coke oven to a humidity control facility.

[0002]

2. Description of the Related Art FIG. 1 shows an example of a blended coal processing flow for adjusting coke oven charge coal, that is, an example of a blended coal transport flow from a blended coal bedding yard to an outlet of a humidified coal facility (upstream side 2). System, one system on the downstream side). Reference numerals 1 and 2 in the drawing indicate piles (1st and 2nd systems) of blended coal formed by laminating coking coals of various brands at a predetermined blending ratio.

[0003] In general, blended coal of each system is constructed (pile-formed) by stacking caking coal or fine caking coal so that it can be mixed with each other to form charged coal. Hereinafter, such blended coal is referred to as “normal blended coal”. FIG. 3 shows a laminated form of the blended coal pile. Conventionally, normal coal blends of the first and second series are cut out from the blended coal bedding yards 1 and 2 and conveyed by belt conveyors 3 and 3 'and temporarily stored in the wet coal hoppers 4 and 4'. The hoppers 4, 4 ′ are cut out at a predetermined cut-out ratio by a fixed amount cut-out device 5, 5 ′ attached to the hoppers 4, 4 ′. Measured. afterwards,
After blending the 1 and 2 system coal blends at a predetermined ratio,
It is weighed by the weighing device 7 and then charged into the humidifying coal equipment 10 and humidified (dried) in the humidifying coal equipment 10 so that the moisture content becomes a predetermined value. After the moisture content of the adjusted coal is measured by the moisture meter 8, it is supplied to a coke oven (not shown).

[0004] The moisture conditioning coal facility 10 receives the blended coal mixed at a predetermined ratio into a rotary kiln type dryer 11 for drying by an indirect heating method, as shown in FIG. 2, for example. While the dryer 11 is being driven to rotate, the humidity is adjusted while being sent to the outlet side. Therefore,
The humidity conditioning equipment 10 includes a driving device 13 for driving the dryer 11, a steam input device 14 for inputting heating steam as an indirect heating source into the dryer 11, and the driving device 13 and steam input. A control device 12 for controlling the device 14 is provided.

The control unit 12 controls the drive unit 13 based on, for example, the cutout signal of the fixed amount cutout unit 5 and the weighing value of the weighing device 7 for measuring the cutout amount so that the heat transfer area in the coal dryer becomes constant. A drive control unit 20 for controlling the amount of driving (coal feed speed: inversely proportional to the number of revolutions); Calorific value, coal temperature (measured with thermometers on the inlet and outlet sides of equipment not shown), coal processing amount
(Information from the drive control unit 20), and the deviation of the measured value of the moisture meter 8 on the outlet side of the equipment with respect to the target moisture value is fed back to the above calculation result to correct the calculated steam pressure. (Japanese Unexamined Patent Application Publication No. 9-328
No. 689).

[0006]

[Problems to be Solved by the Invention] By the way, recently, as a coke oven charging coal, a coal blend having a significantly higher moisture content than the coal type (caking coal, fine caking coal) usually used for blending coal is mainly blended. Attempts have been made to use blended coal. Such coal blends have significantly different characteristics (such as the degree of drying and strength) as compared with the ordinary coal blends described above, so it is not possible to simply mix blended coals with these properties to form a charged coal. . It should be noted that such a blended coal that cannot be simply used for mixing with the regular blended coal will be referred to herein as “unusual blended coal” for convenience.

By the way, as shown in FIG. 3 (a), for example, the above-mentioned unusual blended coal has a laminated form (pile structure).
Also, unlike conventional coal blends (FIG. 3 (b)), bedding yards for piles of these unusual coal blends are often specified. Nevertheless, depending on recent coking coal supply conditions and coke oven operation plans,
In some cases, it is required that one unit of conditioning coal is used to alternately process normal blended coal and non-normal blended coal. In such a case, for example, if one of the systems is a normal blended coal and the other is an unconventional blended coal in FIG. 1, it is impossible to mix and control the humidity as described above. Must be stored in the wet coal hopper 4, 4 '. Then, each of these wet coal hoppers 4, 4 'is cut out separately and, for example, according to a request of a coke oven, for example, 1
System: 2 systems = 100%: 0%, or 1 system: 2 systems = 0
%: 100%, so that it is supplied to the humidification equipment.

FIG. 4 shows the transition of the time from heating steam pressure to moisture conditioning coal moisture when switching from non-normal coal blend to normal coal blend. As shown in this figure,
According to the conventional method, for a switching period of about 20 minutes,
The dead time h ₁ and the time constant h ₂ each take about 400 seconds,
These times (h ₁ + h ₂ ) accounted for a large proportion of the total time, and this was one of the factors that reduced the operating accuracy of the humidifying coal facility.

[0009]

SUMMARY OF THE INVENTION The main object of the present invention is to provide:
When charging coal blends with different properties that are difficult to mix, especially coal blends with different moisture values, the fluctuations in the coal moisture due to delays in the humidity control operation due to the differences in properties are considered when charging coal blends. It is to propose a technique for suppression.

[0010] For the above-mentioned purpose, when alternately blending coal blended (normal blended coal and unusual blended coal) having significantly different moisture values from the wet coal hopper, the cut-out amount is determined according to each blended coal moisture value. The adjustment is effective in suppressing the delay of the humidity control, and this has led to the development of the present invention, which has been found to enable a constant water content (humidity charging coal). That is, the present invention provides a method for supplying blended coal to a coke oven facility, wherein the coke oven charge coal is conditioned using a humidifier facility prior to charging the coke oven. When switching and supplying multiple types of coal blends with different amounts,
This is a method for charging blended coal into a humidified coal facility, characterized in that the amount of blended coal cut out from the wet coal hopper is determined and supplied according to the water content of the blended coal before and after switching.

Further, the present invention provides a method in which the initial heating steam pressure in the dryer is kept constant when the moisture value of the blended coal before switching is high but the moisture value of the blended coal after switching is low. In the case where the cut-out amount of the low-moisture blended coal after switching is increased, while the moisture value of the blended coal before switching is low but the moisture value of the blended coal after switching is high, the initial heating in the dryer is performed. It is preferable to perform control so as to reduce the cut-out amount of the high moisture value blended coal after switching under the condition that the steam pressure is kept constant.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to supplying blended coal cut out from a bedding yard to a blender in order to obtain a blended coal for a coke oven. In the case where it is required to alternately supply the blended coal with the ordinary blended coal, a method for promptly performing appropriate humidity control for the difference in moisture value between the blended coals is proposed. That is, according to the difference in the moisture value, the operating conditions of the humidity conditioning coal equipment in the initial stage are particularly fixed so that the heating steam pressure of the moisture conditioning coal equipment, the target moisture on the dryer side, the heat transfer coefficient and the throughput can be appropriately controlled. Below, it is a method of performing the initial operation of the humidified coal facility by determining the supply amount linked to the moisture value of the blended coal.

By supplying such blended coal, it is possible to minimize the delay in response for controlling the steam pressure supplied to the humidifying coal facility. FIG.
In the operation of the humidifying coal facility for controlling the humidity of the humidified coal of the charged blended coal to a constant value by suppressing the heating steam pressure to be charged into the dryer 11, the method of the present invention is performed until the humidified moisture value is reached. It has been found that this requires only about 20 minutes, while the conventional general charging method takes about 25 minutes.

That is, when comparing the supply method according to the conventional method (supplying the supply amount is fixed and controlling the heating steam pressure) with the method of the present invention, the “dead time (h ₁ , H ₁ )” and the “time constant (h ₂ , H ₂ ) ”are all shortened by using the method of the present invention. Therefore, according to the method of the present invention, it is possible to supply charged coal with more stable moisture to a coke oven as a charging destination.

[0015] The blending coal supply method according to the present invention means that when the moisture value of the blended coal before switching is high but the moisture value of the blended coal after switching is low, the initial heating steam pressure in the dryer is reduced. Under the condition of constant, while increasing the cut-out amount of low moisture value blended coal after switching,
If the moisture value of the blended coal before switching is low but the moisture value of the blended coal after switching is high, the high moisture blended coal after switching is provided under the condition that the initial heating steam pressure in the dryer is kept constant. This is a method of controlling so as to reduce the cutout amount.

In the above description, an example of the charging method for two types of blended coals having different characteristics such as different amounts of water and cannot be mixed and charged with each other has been described. The same effect can be obtained by applying the charging method based on the same concept.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A description will be given of results obtained by adopting a supply method conforming to the method of the present invention and applying it to the actual operation of a humidified coal facility incorporated in the coal conveyance flow of FIG. Unusual blended coal and regular blended coal were alternately charged into this humidified coal facility at a pitch of about 20 minutes in response to a request from a coke oven. Humidity control was performed using the humidity control equipment shown in FIG. Then, the supply amount of each blended coal to the dryer 11 of this facility was determined based on each moisture value of the blended coal before and after the switching (the initial heating steam pressure in the dryer: constant at 1.8 × 10 ⁵ Pa). In other words, when switching from non-normal blended coal to regular blended coal, the water content of each blended coal was 10 wt% and 8.5 wt%. Conversely, when switching from blended coal to unusual blended coal, 105t
The operation to lose weight was performed. By performing such adjustment of the supply amount based on the moisture value of the blended coal, the heating steam pressure (1.5 × 10 ⁵ Pa) at the time of reaching the humidified coal moisture from the heating steam pressure (1.8 × 10 ⁵ Pa) at the initial stage of the supply. By appropriately changing the setting to Pa), both the dead time H ₁ and the time constant H ₂ could be greatly suppressed as shown in FIG. In addition, when switching from normal blended coal to non-regular blended coal, after performing the weight reduction operation, if the amount of non-regular blended coal is increased while gradually increasing the heating steam pressure, the moisture control remains stable. It is possible to change the humidity control amount.

[0018]

As described above, according to the present invention,
This makes it possible to suppress a delay in response of moisture control when switching coal blends in the case where blended coals having different characteristics, particularly different amounts of retained moisture, are alternately humidified. Therefore, the humidity control of the coke oven charging coal can be realized with high accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram of a blended coal transport flow from a blended coal bed yard to a humidified coal facility outlet side.

FIG. 2 is a block diagram of a humidifying coal facility.

FIG. 3A is a schematic diagram illustrating a pile configuration of non-normal blended coal, and FIG. 3B is a schematic diagram illustrating a pile configuration of regular blended coal.

FIG. 4 is a graph showing a water response of a system ranging from a heating steam pressure to a humidified coal water.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1 type coal blended bed 2 2 type coal blended bed 3 belt conveyor 4 wet coal hopper 5 quantitative cut-out device 6 hopper output side (equipment entrance side) Moisture meter 7 weigher 8 equipment exit side moisture meter 10 humidifier Equipment 11 Dryer 12 Controller

Continued on the front page (72) Inventor Osamu Iida Okayama Prefecture Kurashiki City Mizushima Kawasaki Dori (No address) Kawasaki Steel Corporation Mizushima Works F-term (reference) 4H012 RA01

Claims (2)

[Claims] When a coke oven charged coal is humidified using a humidified coal facility prior to charging the coke oven into a coke oven, the method of supplying the blended coal to the humidified coal facility includes a method for controlling the moisture content of the coal. When switching between different types of coal blends, the amount of coal blended from the wet coal hopper is determined and supplied according to the moisture content of the coal blend before and after the switching. How to charge blended coal into wet coal equipment. 2. When the moisture value of the blended coal before switching is high but the moisture value of the blended coal after switching is low, the blending coal after switching is changed under the condition that the initial heating steam pressure in the dryer is kept constant. If the moisture content of the blended coal before switching is low but the moisture value of the blended coal after switching is high, while the cutout amount of the blended coal with low moisture value is increased, the initial heating steam pressure in the dryer is constant. Under the condition of reducing the cut-out amount of the high moisture value blended coal after switching,
The method for supplying blended coal according to claim 1, wherein: