JP2000282054A - Humidity control of coal fed into coke oven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for controlling the humidity of coal fed into a coke oven, capable of maintaining the excellent precision of humidity control even if ordinary coal and unordinary one are alternately subjected to humidity control. SOLUTION: In a method for controlling the humidity of coal fed into a coke oven in which the humidity control of a coal blend before being fed into the coke oven is carried out using a coal humidity-controlling equipment 10 employing a moisture meter 8 installed outside the exit of the equipment 10 as a moisture control means, working curves 21A and 21B for the moisture meter 8 are retained respectively for plural kinds of coal blends and the switchover of the working curves, in being applied, based on information learned through tracking the coal blends is carried out when feeding the plural kinds of mutually immiscible coal blends into the equipment 10 one after another in any order.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A conventional method for controlling the humidity of coal charged in a coke oven will be described with reference to the drawings. Fig. 2 (a) shows an example of the coal transport flow from the blending bed to the outlet of the humidification equipment (two upstream systems and one downstream system). This is a first- and second-system blended bed in which blended charcoal formed by laminating according to the blending ratio is arranged for each blending ratio. Conventionally, the blended coal of each system is composed of ordinary caking coal / fine caking coal which can be mixed with each other. This is called "normal coal". FIG. 3B shows the lamination form.

[0003] The coal blends of system 1 and system 2 are conveyed from these blending beds on a belt conveyor 3 and temporarily stored in a wet coal hopper 4, and a predetermined cut-out ratio is appropriately determined by a fixed amount cut-out device 5 attached to each wet coal hopper 4. The coal moisture is measured for each system by the moisture meter 6 on the hopper outlet side (equipment entrance side), and after mixing the first and second systems, it is weighed by the weighing device 7 and then charged into the humidified coal equipment 10. The moisture is conditioned (dried) so that the amount of moisture contained in the humidified coal facility 10 becomes a predetermined value, and the moisture content of the conditioned coal is measured by the moisture meter 8 on the outlet side of the facility. Not supplied to the coke oven.

As shown in FIG. 2B, for example, as shown in FIG. 2 (b), a humidifying coal facility 10 has a rotary kiln type dryer 11 that receives coal and indirectly heats and dries it. A driving device 13 for feeding the drying device 11, a steam input device 14 for inputting heating steam as an indirect heating source to the dryer 11, and a control device 12 for controlling the driving device 13 and the steam input device 14. Control device
Reference numeral 12 denotes a drive amount of the drive unit 13 (coal feed speed; rotation speed) such that the heat transfer area of the coal in the dryer is constant based on the cutout signal of the fixed amount cutout device 5 and the weighed value of the cutout amount measuring device 7, for example. A drive control unit 20 for controlling the
Using the measured value of the moisture meter 6 on the inlet side of the equipment as the initial moisture value, the amount of heat required for it to reach the target moisture value on the outlet side of the equipment, coal temperature (measured by thermometers on the inlet and outlet sides of the equipment not shown) and coal treatment The calculation is performed under the limitation of the 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 calculation result to correct the calculated steam pressure. (See JP-A-9-328689).

An infrared moisture meter (IR moisture meter) is used as the moisture meters 6 and 8. The IR moisture meter irradiates an object with infrared rays and measures and outputs the absorption rate.On the other hand, the humidity control controls the moisture value by JIS analysis.
It is necessary to convert the output value of the IR moisture analyzer to a JIS analysis value, and therefore a calibration curve as shown in FIG. 4 is used. However, since the output characteristics of the IR moisture analyzer depend on the particle size composition and color of the object to be measured, for example, periodically at a cycle of about one month or whenever the constituent brand of the coal blend is changed, etc. In addition, sampling of coal, correlation analysis with JIS analysis values were performed, and the calibration curve was reviewed to maintain the humidity control accuracy. In FIG. 2 (b), the calibration curve 21A expressed by the mathematical formula
Although the form stored in 1 is shown, it may be stored in each of the moisture meters 6 and 8 instead of the humidity control unit 21.

[0006]

By the way, as the coal charged to the coke oven, a blended coal mainly composed of a coal having a higher moisture content than the coal type of normal coal (coking coal / coking coal) is applied. There are cases. This blended coal cannot be mixed with normal coal because of its drastically different strength properties from ordinary coal. Such blended coal that cannot be mixed with ordinary coal is referred to herein as "unusual coal" for convenience. As shown in FIG. 3 (a), for example, as shown in FIG.
), And generally, the formulation bed is fixed to a particular system. On the other hand, depending on the operation plan of the coke oven, it is required that one regular humidified coal facility alternately processes normal coal and non-normal coal.

At this time, for example, assuming that one of the systems is normal coal and the other is non-normal coal in FIG. 2 (a), these are stored in the wet coal hopper 4 for each system, and the cutout ratio therefrom is determined by the destination. Depending on the coke oven, it is necessary to switch from system 1: system 2 = 100%: 0% or system 1: system 2 = 0%: 100%.
The switching cycle is much shorter (eg, about 20 minutes) than the calibration curve review cycle (eg, about one month).
Further, since the normal coal and the non-standard coal have different particle size configurations and colors, both calibration curves are different as shown in FIG. 5 (a: non-standard coal, b: normal coal), for example. In this example, even if both JIS analysis values are the same, the output value of the IR moisture meter is larger for non-standard coal.

Since the moisture meter 6 on the inlet side of the equipment is arranged for each system, there is no problem if a calibration curve suitable for the coal blend fixed to each system is provided, but there is no problem. Is 1
Since the system and the system are measured alternately, the use of a calibration curve suitable for one degrades the humidity control accuracy during the other process. Therefore, the moisture meter 8 on the outlet side of the equipment
Although a calibration curve that is a compromise of the calibration curve of unconventional coal is used, it is far from a sufficient level with some improvement in accuracy.

Accordingly, an object of the present invention is to provide a method of controlling the humidity of a coal charged into a coke oven, which can maintain good humidity control accuracy even when the normal coal and the non-normal coal are alternately conditioned.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a coke oven charging coal for humidifying blended coal before charging a coke oven by using a humidifying coal facility using at least a moisture meter on the outlet side of the facility for humidity control. In the humidity control method, when a plurality of immiscible blended coals are sequentially charged into the moisture conditioning facility in random order, the calibration curve of the moisture meter is held for each blended coal type, and these calibration curves are defined as blended coal. And a method for controlling the humidity of the coke oven charging coal characterized in that the method is switched based on information obtained by tracking the coal.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the present invention, various types of coals are provided by retaining calibration curves used for a moisture meter on the equipment outlet side for each type of blended coal and switching between them based on tracking information of blended coal. No matter how random the seeds are placed in the humidifying coal equipment and processed, it is possible to measure each coal type by linking it to a calibration curve suitable for that type. Can be maintained.

Hereinafter, tracking of blended coal will be described with reference to the drawings. FIG. 1 shows an example of an embodiment of the present invention in a situation where normal coal and non-normal coal allocated to the first and second blending beds 1 and 2 in FIG. 2 (a) are alternately humidified. 3A is a block diagram, and FIG.
A and 21B are provided, and (b) shows two moisture meters on the outlet side of the equipment.
This is an example in which two calibration curves 21A and 21B are divided into A and 8B. In FIG. 1, 30 is a tracking unit that tracks the coal blend and switches the calibration curves 21A and 21B in (a), and a tracking unit that switches the input data from the moisture meters 8A and 8B in (b) based on the information. A rotation speed measuring device 100 for measuring the rotation speed of the dryer 11 is a host computer, and the same or corresponding members as those in FIG.

The host computer 100 has information such as the type of coal and the processing amount of the blended coal from the blended bed to the wet coal hopper 4.
Command the cutout timing and cutout ratio. When the fixed amount extraction device 5 performs the extraction, it sends a signal to that effect (extraction signal) to the tracking unit 30. The tracking unit 30 constantly captures the rotation speed data of the rotation speed measuring device 31 and, when a cutout signal (in this case, it is not transmitted simultaneously from the two quantitative cutout devices) is received (tracking start point), At about the same time as starting the operation (tracking operation) for tracking the subsequent transport position of the cut coal from the transport speed corresponding to the several data, the coal type data of this coal is obtained from the host computer 100. When the result of the tracking operation reaches a value corresponding to the position (coordinate value) of the moisture meter on the equipment outlet side (tracking end point), the calibration curve is switched to the one corresponding to the obtained coal type data. In this way, the moisture meter on the outlet side of the equipment can always execute the measurement using the calibration curve suitable for the measured object, and the measurement accuracy of the coal moisture and the accuracy of the humidity control are reliably maintained.

Here, the case where two types of blended coals cannot be mixed with each other has been described as an example, but it goes without saying that the same effects can be obtained by the present invention even if there are three or more types of coal blends. In addition, if it is not general, but the moisture meter on the equipment entrance side is not assigned to each compound bed system, the moisture meter on the equipment entrance side and the moisture meter on the equipment exit side described above Taking measures similar to those taken will give equally good results. In this case, the calibration curve switching timing of the moisture meter on the equipment input side may be directly instructed from the host computer.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to the actual operation of a humidified coal facility incorporated in the coal conveying flow shown in FIG. 2A will be described. Non-conventional coal (coal A) and non-conventional coal (coal B) are alternately charged into the humidified coal facility at a pitch of about 20 minutes in response to a request from a coke oven. The humidity control is performed by the method described with reference to FIG. In this embodiment, the present invention was carried out in the form shown in FIG. The calibration curves are two types shown in Fig. 5 (a: unconventional charcoal, b: normal charcoal).
8B has b. Then, when the coal type at the tracking end point is the coal type A, the moisture meter 8A is selected, and when the coal type is the coal type, the moisture meter 8B is selected and used until the next tracking end point.

As a result, the variation (standard deviation) of coal moisture, which was 0.3% before application of the present invention, was reduced to 0.1% in the embodiment.
Reduced to

[0017]

As described above, according to the present invention, an excellent effect that the humidity control accuracy can be maintained satisfactorily even when the humidity of the normal coal and the non-standard coal are alternately controlled is exhibited.

[Brief description of the drawings]

FIG. 1 shows an example of an embodiment of the present invention ((a) is an example in which the controller has two types of calibration curves, and (b) is an example in which two types of calibration curves are separately provided in the two moisture meters on the equipment exit side. FIG.

FIG. 2 (a) is a block diagram showing an example of a coal conveying flow from a blending bed to the outlet of a humidifier, and FIG. 2 (b) is a block diagram showing an example of a humidifier.

FIG. 3 (a) is a schematic view showing a non-ordinary coal, and FIG. 3 (b) is a schematic view showing a laminated form of ordinary coal.

FIG. 4 is a schematic diagram showing a calibration curve of an IR moisture meter.

FIG. 5 is a graph showing an example of a calibration curve for non-normal coal (a) and normal coal (b).

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 Mixing bed of 1 system 2 Mixing bed of 2 system 3 Belt conveyor 4 Wet coal hopper 5 Quantitative cut-out device 6 Moisture meter at hopper outlet side (equipment inlet side) 7 Weighing device 8, 8A, 8B Moisture meter at equipment outlet side 10 Humidifying coal equipment 11 Dryer 12 Control unit 13 Drive unit 14 Steam input unit 20 Drive control unit 21 Humidity control unit 21A, 21B Calibration curve 30 Tracking unit 31 Revolution speed measuring instrument 100 Host computer

Claims (1)

[Claims] 1. A method of controlling the humidity of a coal charged into a coke oven, in which at least a moisture meter on the outlet side of the facility is used for humidity control to adjust the blended coal before charging the coke oven, the mixing cannot be performed. When charging plural types of blended coal into the conditioning coal facility sequentially and indefinitely, the calibration curve of the moisture meter is held for each blended coal type, and these calibration curves are obtained by tracking the blended coal. A method for controlling the humidity of a coal charged into a coke oven, wherein the method is switched and used based on the humidity.