JPH0275694A - Method for controlling rate of cutting and discharging coke in coke dry quenching equipment - Google Patents

Abstract

PURPOSE:To greatly reduce the change in the rape of cutting and discharging coke to thereby stabilize the operation of coke dry quenching equipment and improve the heat recovery efficiency by utilizing a specified control method for controlling the rate of cutting and discharging coke in the coke dry quenching equipment. CONSTITUTION:A method for controlling the rate of cutting and discharging coke in coke by quenching equipment, which comprises establishing a rate of charging red-hot coke into a cooling tower 1 at a prescribed time as a rate of cutting and discharging cooled coke by a cutting and discharging device 4 based on the schedule of the coke push-out operation in a coke oven; estimating at the same time the stocks of red-hot coke in a prechamber 2 during a prescribed period of time when the coke is continuously cut and discharged at the above-mentioned rate; and automatically correcting the set value of the rate of cutting and discharging coke when the estimated stock value is outside a preestablished target range, thus controlling the rate of cutting and discharging coke.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for automatically controlling the amount of coke cut out in a coke dry extinguishing facility (hereinafter referred to as CDQ).

<Prior Art> Red-hot coke extruded from a coke oven is treated with wet or dry extinguishing equipment to become cooled coke.

When red-hot coke is treated with CDQ, the red-hot coke is first charged into the brie chamber at the top of the cooling tower through a packet, and cooling gas is supplied upward from the bottom of the cooling tower to remove the red-hot coke. The coke descends within the tower while being cooled and reaches the cooling chamber at the bottom of the cooling tower, after which it is cut out in predetermined amounts by a cutter provided at the bottom of the cooling chamber and discharged outside the cooling chamber.

The weight of this cooled coke discharged per hour is called the cutout amount, and this cutout amount is usually set empirically by the CDQ operator by checking the progress of coke extrusion work in the coke oven and the amount of coke stock in the prechamber. Therefore, a method was adopted in which the set value of the cutting amount was changed as needed according to changes in these conditions.

However, such operations by an operator have their own limitations, and there are problems such as frequent changes in set values, resulting in a lack of thermal balance.

For this purpose, we set the amount of red hot coke charged and cut out into the cooling tower of CDQ, and then measured the level of the red hot coke layer in the cooling tower at any point during CDQ operation and the level of red hot coke in the coke extruder from this point onwards. For example, Japanese Patent Laid-Open No. 53-57201 proposes a method of automatically correcting the cutting amount based on the operating time until the scheduled stoppage.

<Problems to be Solved by the Invention> The purpose of the above method is to continue cutting out the cooled coke in the CDQ even when the coke extrusion operation of the coke oven is suspended. Automation of settings is achieved, but the inventory level of red-hot coke in the pre-chamber immediately before the extrusion operation stop is set as a control target, and each time coke is charged into the pre-chamber, the weight of charged coke (tons/time) and the pre-chamber are Since the cutting amount is set based on the inventory amount of internal coke, the cutting amount is inevitably set to a certain level due to measurement errors in the weight of charged coke and errors in detecting the inventory level of coke, which is a mixture of powdered coke. It will fluctuate significantly from cycle to cycle. This causes problems in that the thermal balance within the CDQ system is disturbed, which promotes fluctuations in the amount of generated steam and a decrease in heat recovery efficiency.

Also, although it depends on the target value of the inventory level in the pre-chamber just before the extrusion operation is stopped, if charging into the CDQ is concentrated just before the extrusion operation is stopped due to variations in the extrusion operation time, the throughput in the CDQ may be exceeded. There is also the risk of interruptions in coke extrusion operations.

An object of the present invention is to solve the above-mentioned problems in CDQ operation and provide an automatic control method for the amount of coke cut out with less fluctuation in the cutout amount and high heat recovery efficiency.

<Means for Solving the Problems> According to the present invention, in order to achieve the above object, in a coke cutting amount control method of a coke dry extinguishing equipment, red-hot coke is controlled in a predetermined time based on a coke extrusion work schedule of a coke oven. The cooling tower charging speed is set as the amount of cooled coke to be cut out, and the amount of red hot coke in stock in the brie chamber within a predetermined time is predicted when continuous cutting is performed at this amount of cut out. Provided is a method for controlling the amount of cut-out of coke dry extinguishing equipment, characterized in that the set value of the cut-out amount is automatically corrected when the set value of the cut-out amount is out of a preset target range.

The present invention will be explained in more detail below.

FIG. 1 is an explanatory diagram of the main part of CDQ to which the present invention is applied.

Red-hot coke is charged into a pre-chamber 2 at the top of the cooling tower 1, cooled while descending inside the cooling chamber 3 at the bottom of the cooling tower 1, and discharged to the next process via a cutting device 4 and a discharge device 5. . 6 is a level meter installed on the top of prechamber 2 for detecting the inventory level of charged coke, and can be selected from commonly known methods, such as continuous measurement using a sensor using microwaves. It is supposed to be done.

The present invention is a method for automatically controlling the amount of cut-out CDQ, which calculates the coke charging speed to the CDQ within a predetermined time based on the extrusion operation time of the coke oven,
This charging speed is set as the amount of cooled coke cut out, and an equal amount is cut out, and the amount of red hot coke present in the pre-chamber within a predetermined time from the present to the future when continuous cutting is performed at the said cut-out amount is calculated. predict, and automatically correct the cut-out amount set value when the predicted inventory amount falls outside the target range of the pre-chamber inventory management level set in advance;
The number of operations of the cutting device is controlled.

By selecting the predetermined time and the target range of the inventory control level in the pre-chamber, the number of times the cutting amount is corrected is extremely small, and stable CDQ operation can be performed.

The method of calculating the cutting amount set value will be explained below.

Figure 2 shows an example of a coke oven extrusion work schedule, but coke oven operations generally operate in blocks with about an hour of down time between operations. From the extrusion work schedule planned in advance in this manner, the planned amount of coke to be charged to the CDQ at a predetermined time t is determined, and the coke charging rate x (tons/h) to the CDQ is roughly determined. Note that the predetermined time t may be arbitrarily determined, but generally if it is less than 8 hours, as shown in FIG.
This is not desirable because the accuracy of the amount of coke charged into the CDQ is poor due to delays in coke oven work.

The planned amount of coke to be charged is determined by multiplying the number of coke extrusions by the most recent actual value of the average coke weight per extrusion.

Next, the set value y (tons/h) of the amount of cooled coke cut out is determined from the coke charging rate X obtained by the above method as y=x. That is, this means that the coke is cut out at the same cutting rate as the coke charging speed into the CDQ.

However, if this cutout amount set value is used as is, problems will occur in the following cases. For example, the fourth
As shown in the figure, if the current inventory amount is large, if the cutout amount set value determined by y=x is used as is, the inventory amount in the pre-chamber will exceed the upper limit value, causing a problem in coke oven operation.

Therefore, as a countermeasure to this, a target range is determined in advance for the amount of inventory in the pre-chamber, and a predicted value of the amount of inventory at a predetermined time t is calculated based on the coke charging schedule to the CDQ, the cutout amount setting value y, and the current storage amount Q. Qt is calculated, and if the predicted value Qt of the inventory amount is outside the target range, the cutout amount setting value y is corrected.

Here, instead of setting a target value for the inventory amount at a certain point in time and controlling the inventory amount as in JP-A No. 53-57201, a method is adopted in which a target range is set and the inventory amount is maintained within that range. The reason is that coke is a powder mixture, and level detection sensors such as microwaves have a large error in detecting the inventory amount.
This is because if the target value is controlled based on this value, the cutting amount will vary greatly.

FIG. 5 shows the changes in the set value of the cooled coke cutting amount and the red hot coke inventory amount in the present invention.

Now, when CDQ is operated at y=x, the inventory amount transition shown by the solid line in Figure 5 is predicted, and t.

The predicted value Qt+ of the inventory amount at the time of elapsed time is within the target range (QH ~ QL
), 1. Until the elapsed time, y=x+ (Q
By correcting the cutout amount setting value as t+-Qo (orQL) ) /l+ and setting the cutout amount as y=x after t1, the inventory amount changes within the target range as shown by the broken line. Can be done.

Of course, if the predicted value Qt is within the target range from the beginning, the cutting amount is set as y=x.

The target range for the inventory amount may be set, for example, at 20 to 80% of the capacity of the chamber. Furthermore, a commonly used sensor such as a microwave sensor may be used to measure the inventory amount.

Next, a method for automatically controlling the cutting amount of the present invention in CDQ will be explained.

FIG. 6 is a cutout amount control system diagram of the present invention in CDQ, and FIG. 7 is an example of a calculation flow diagram.

First, when the coke extrusion work schedule of the coke oven for the current day and the next day is registered in advance in the furnace schedule setting device 7, the charging speed calculator 8 calculates the charging speed of coke to be charged into the CDQ.

Next, the cutting device drive control device 11 controls the number of operations of the cutting device 4 via the cutting amount calculator 9 and the cutting amount setting device 10. The cutting amount is always maintained at the same amount.

Reference numeral 12 denotes an inventory amount prediction calculator, which uses the setting value determined by the cutting amount calculator 9, the extrusion work schedule from the furnace schedule setting device 7, and the current stock amount from the inventory amount level detector 13, to A predicted inventory amount for a predetermined period of time from the present to the future, for example 8 hours, is calculated.

The obtained value is compared with the target range value set in the target range setter 14 in advance, and if there is a point t8 that exceeds this target range, this 1. A correction value for the cutting amount is calculated by the cutting amount corrector 15 from the predicted value Qtx of the inventory amount at that time, and the corrected value is input to the cutting amount setting device 10. Reference numeral 16 denotes a correction value cancellation timer, and after seven hours have elapsed, the correction of the cutting amount is canceled, and the result from the cutting amount calculator 9 is directly input to the cutting amount setting device 10.

As described above, the set value of the cutting amount is automatically calculated and set, and automatic control of the cutting amount is achieved.

<Example> The present invention will be specifically explained below based on Examples.

(Example 1, Comparative Example 1) Red-hot coke extruded from a coke oven operated according to the extrusion schedule shown in Fig. 2 is controlled by the method of the present invention to control the amount of cooled coke cut out using the CDQ shown in Fig. 1. Dry fire extinguishing work was carried out. The target range of red hot coke inventory in the pre-chamber is 20 to 8 of the pre-chamber capacity.
0%, the predetermined time is 8 hours, and the amount of coke cut out per time is 2
0 tons (Example 1).

The changes in the amount of red hot coke in stock in the prechamber, the amount of cooled coke cut out, and the heat recovery efficiency were as shown in FIG. 8a.

For comparison, in the same CDQ as in the above example, instead of the target range of red hot coke inventory, the red hot coke inventory level in the pre-chamber immediately before the stoppage of coke extrusion work was set at 150 tons, and the amount of coke cut out at one time was set as 150 tons. 20 tons, and dry extinguishing of coke was carried out using the automatic control method disclosed in Japanese Patent Application Laid-open No. 53-57201 (Comparative Example 1).

The changes in the amount of red hot coke in stock in the pre-chamber, the amount of cooled coke cut out, and the heat recovery efficiency were as shown in Figure 8b.

This figure shows that in Comparative Example 1, in order to control the inventory level just before the coke extruder stops to the target level, the cutout amount must be changed frequently, which causes the red-hot coke to not be cooled uniformly. It can be seen that the heat recovery efficiency is low and fluctuations are large.

On the other hand, Example 1 predicts the inventory level within a predetermined time (8 hours) from the present to the future,
The set value of the cut amount, that is, the number of times of cutting, can be changed so that the predicted level is within the target range, and the set value of the cut amount can be corrected only when it is about to go out of the target range.
As shown in Figure 8a, the number of changes in the cutting amount setting is small,
It can be seen that the red-hot coke is also cooled uniformly, so the heat recovery efficiency is high and stable.

<Effects of the Invention> Since the present invention is configured as described above, the amount of cooled coke cut out in CDQ is set from the extrusion work schedule of the coke oven, and the amount of pre-cooled coke is controlled using the cutout amount. This method predicts the chamber inventory amount and automatically corrects the cutout amount when it falls outside of a preset target range, so changes in the cutout amount can be significantly reduced, reducing COQ operation. Heat recovery efficiency can be improved by stabilizing .

Further, the present invention is a control method that is safe because it can predict the amount of inventory and automatically take action, and does not require operator intervention, which solves all the problems of the conventional method at once.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the main parts of CDQ. FIG. 2 is a diagram showing a coke oven extrusion work schedule. FIG. 3 is a graph showing the relationship between actual coke charging amount, planned ratio, and charging work time. FIG. 4 is a graph showing the relationship between the coke charging speed to the CDQ and the inventory amount transition. FIG. 5 is a graph showing the relationship between the cooled coke cutting amount set value and the red hot coke inventory amount transition. FIG. 6 is a control system diagram of the present invention. FIG. 7 is a calculation flow. FIG. 8a is a graph showing the changes in the stock amount of red hot coke, the amount of cooled coke cut out, and the heat recovery efficiency in the method of the present invention and FIG. 8b in the conventional method. Explanation of symbols 1...Cooling tower, 2...Brie chamber, 3...Cooling room, 4...Cutting device, 5...Discharge device, 6...Inventory level meter, 7... - Furnace schedule setting device, 8... Charging speed calculator, 9... Cutting amount computing device, 10... Cutting amount setting device, 11... Cutting device drive control device, 12...・Inventory amount prediction calculator, 13... Level detector, 14... Target range setter, 15... Cutting amount corrector, 16... Timer

Claims (1)

[Claims] (1) In a method for controlling the amount of coke cut out of coke dry extinguishing equipment, the charging rate of red hot coke to the cooling tower in a predetermined time is set as the amount of cooled coke cut out based on the coke extrusion work schedule of the coke oven, and the The amount of red hot coke stocked in the pre-chamber within a predetermined time when continuous cutting is performed at the output amount is predicted, and when this predicted inventory amount is outside a preset target range, the set value of the cutout amount is automatically changed. A method for controlling the cutout amount of coke dry extinguishing equipment, which is characterized by making corrections.