JPH06287647A - Operation of sintering machine - Google Patents

Abstract

PURPOSE:To stabilize a calcination in the advancing direction of sintering by calculating an exhaust gas temp. pattern from the exhaust gas temp. measured value in a wind box and adjusting pallet velocity in the case of deviating from the aim temp. CONSTITUTION:The exhaust gas temp. measured with a thermocouple 10 in each wind box 8 is inputted in a calcination distance device 20. The calcinating point is detected from the variation in the exhaust gas temp. and the average calcination distance in the width direction of the pallet is calculated and outputted to an exhaust gas temp. predicted value arithmetic unit 19. The exhaust gas temp. predicted value arithmetic unit 19 corrects the calcination distance based on the exhaust gas predicted value and the corrected calcination distance is outputted to a calcinating point control arithmetic unit 21. The calcinating point control arithmetic unit 21 finds the pallet velocity for obtaining the aimed calcination distance from the corrected calcination distance, the calcination distance aimed value inputted from a manual setter 22, the packing layer thickness value inputted from a packing layer thickness meter 18, the pallet velocity measured value inputted from a pallet velocity detected adjusting device 23 and the main exhaust gas vol. measured value. This pallet velocity is given to the pallet velocity detected adjusting device 23 to adjust the setting value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of operating a DL type sintering machine, and more particularly, by dramatically stabilizing firing in the sintering progressing direction, improving productivity and quality of sintered ore. The present invention relates to a sintering operation method for stabilizing the temperature.

[0002]

2. Description of the Related Art As a method for controlling the firing point of a DL type sintering machine, for example, (a) the firing point in each width direction is detected from the exhaust air temperature of the wind box of the sintering machine and based on the average value thereof. To adjust pallet speed (Japanese Patent Laid-Open No. 60-13
No. 032), and (b) a method of comparing the change in the exhaust air temperature pattern of the sintering machine with a set value and adjusting the pallet speed based on the difference (see JP-A-57-125254).
Etc. are known.

[0003]

However, in (a) of the conventional example, since the firing point is detected directly from the exhaust air temperature pattern for each pallet width direction, when uneven firing or the like occurs for each pallet width direction. However, there is a problem that the firing cannot be sufficiently stabilized when the exhaust air temperature pattern in the sintering progressing direction changes.

Further, in view of the problem of the conventional example (a), the conventional example (b) compares the exhaust air temperature pattern with the set value thereof, and although some firing stability is achieved, the raw material is conveyed. Since the change in the exhaust air temperature pattern due to is not taken into consideration and the exhaust air temperature pattern measured at the same timing is compared with the set value, the firing state of the raw material at each position in the sintering progress direction fluctuates. There is a problem that sufficient control accuracy cannot be obtained in the state.

In view of the above problems of the prior art, the present invention predicts the exhaust air temperature when the raw material corresponding to the latest detected firing point passes through each wind box, and fires it from the predicted value. By correcting the points and dramatically stabilizing the firing in the sintering progress direction, we will propose a method of operating a sintering machine that can increase the production amount and stabilize the quality without deteriorating the yield. To do.

[0006]

The present invention provides a method for operating a sintering machine, which detects a firing point from the exhaust air temperature of the sintering machine and adjusts the pallet speed so that the detected value becomes a predetermined value. An exhaust temperature pattern is calculated from the measured exhaust temperature of each wind box, and if the exhaust temperature pattern deviates from the target exhaust temperature pattern, the actually measured exhaust temperature pattern of each wind box and the target exhaust temperature. Using the pattern as a parameter, the detected firing point is corrected, and the pallet speed is adjusted so that the corrected firing point becomes the target firing point. In this method, by tracking the raw material in the sintering progress direction, the latest The method is to predict the future exhaust air temperature of the raw material corresponding to the detected firing point and to use the predicted value to correct the firing point.

[0007]

The method of detecting the firing point and the method of calculating the pallet speed for controlling the firing point according to the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view showing the relationship between the firing point and the exhaust air temperature of each wind box, and FIG. 2 is a plan view showing the arrangement of the above wind boxes and the exhaust air temperature measuring thermocouples arranged therein. Is. That is, the raw material 4 cut out from each raw material tank (not shown) and supplied to the surge hopper 2 is continuously rotated by the rotation of the roll feeder 3 so that the measured value of the raw material charging bulk height meter 1 becomes a predetermined value. Will be supplied on Great 5 of the pallet. The raw material supplied to the ore is conveyed to the ore discharge section by moving the pallet while forming the packed bed 6 having a predetermined layer thickness. Ignition furnace 7 installed during this period near the mining site
The surface of the packed bed 6 is ignited by.

On the other hand, a wind box 8 for sucking the combustion gas generated in the packed bed 6 by the main air blower 9 is installed at the lower part of the transport path of the pallet, and the thermoelectric box arranged in each wind box is installed. The pair 10 measures the temperature of the combustion gas, that is, the exhaust air temperature. Exhaust air temperature is the combustion front 12
-1, 12-2 is almost constant until reaching the pallet grade 5, but the reaching position, that is, the firing point 13-1,
It begins to rise before and after 13-2. The rise of the exhaust air temperature is as shown in the exhaust air temperature transition curves 14-1 and 14-2 of each wind box 8 measured in the pallet width direction according to the movement of the raw material, and the rising points 15-1 and 15- thereof. 2 can be regarded as a firing point in each portion in the width direction.

By the firing point thus detected,
Width average firing distance (distance from firing furnace to firing point)
Is calculated by the following equation (1). The second term on the right side of the equation (1) is a term for correcting an error caused by the fact that the exhaust air temperature measurement in the width direction can be measured at only two points.

[0010] Lffp: Average firing distance in width direction (m) Lffp ₁ , Lffp ₂ : Firing distance (m) obtained from firing points in each width direction α: Correction coefficient (-)

Next, from the firing point and the preset exhaust air temperature of the predetermined air box, the exhaust air temperature predicted value when the raw material corresponding to the latest detected firing point passes through the predetermined air box is as follows ( Calculated by the formula 2), the exhaust temperature target value and the calculated predicted exhaust temperature value are compared, and the corrected firing distance is obtained by the following formula (3). Here, the expression (2) is obtained by tracking the raw material in the sintering progressing direction and using the difference between the most recent firing point detected value of the raw material corresponding to the latest actual exhaust air temperature and the most recent firing point detected value. , Predict the exhaust air temperature of the raw material corresponding to the latest detected firing point. FIG. 3 is a diagram comparing the firing point detected from the exhaust temperature and the estimated value of the exhaust temperature of each wind box at the firing point, where 25 is the predicted exhaust temperature based on the latest (current) firing point, and 26 is Is the actual exhaust temperature, 27
Is the most recent (current) firing point, and 28 is the firing point when the raw material was present at the firing point position when the actual exhaust air temperature was measured.

WBY = 1 / β {Lffp (T ₁ ) −Lffp (0)} + TWB (2) Formula WBY: Exhaust air temperature predicted value (° C.) at current firing distance β: Correction coefficient (m / ° C.) TWB: Exhaust air temperature actual value (° C) T ₁ : Time required to move between firing point detection position and TWB measurement wind box
(min) Lffp (-t): Corrected firing distance detection value (t) before t minutes

LFfp = Lffp−β · (WBA−WBY) (3) Formula LFfp: Firing distance corrected by exhaust air temperature (m) WBA: Exhaust air temperature target value (° C.)

[0014] LWB: Distance from ignition furnace to TWB measurement wind box (m) Ps (-t): Pallet speed measurement value (m / min) t minutes before L ₁₁ : Until firing point detection value changes due to pallet speed change Dead time (min)

The average actual firing rate Vf between firing distances can be calculated from the relationship between the firing rate and the pallet speed in the steady state shown in FIG.
It can be obtained by the equation and the equation (6).

Vf (O) = PsB (O) · h (−L ₁₂ ) / LFfp (O) (5) Formula Vf (−t): Actual firing rate value t minutes before (m / min) PsB (-t): average pallet velocity between t minutes before firing distance (m / min) L _12: dead time before firing point detection value by the filling layer thickness change is changed (min) h (t): t min Previous measured value of packed bed thickness (m)

[0017] Ps (-t): Measured value of pallet speed (t / minute) (m / min) L ₁₁ : Dead time until the detected value of firing point changes due to change of pallet speed (min) Tt: Time required for movement between firing distances ( min) (Tt is a value that satisfies equation (7))

[0018]

If there is no other disturbance, the firing rate changes substantially in proportion to the main exhaust air amount shown in the following equation (8).

[0020] K: Proportional coefficient Q: Main exhaust air volume (Nm ³ / min)

Therefore, the firing rate is, for example, (9) below.
It can be predicted by the formula.

[0022] VfY (-t): t min before firing rate estimated value (m / min) Qs (-t ): t minutes before the main exhaust air volume set value ^(m 3 / mi
n) Q (-t): Measured value of main exhaust air amount before t minutes (m ³ / min) L ₂ : Dead time (min) until the firing point detection value changes due to change of main exhaust air amount

Therefore, the pallet speed Psc for obtaining the target firing distance can be calculated, for example, by the following equation (10) when the target firing distance is given.

[0024] Psc: Pallet speed (m / min) LffpA: Firing distance target value

As described above, the same effect can be obtained by correcting the firing point not by the exhaust air temperature of the specific air box but by the rising gradient of the exhaust air temperature pattern, for example, the method of the following formula (11). .

ΔT = {TWB−TB} / {LWB−Lffp (T ₁ )} (11) Formula ΔT: Ascending slope (° C./m) TB: Base temperature for detecting firing point (° C.)

[0027]

EXAMPLE FIG. 5 is a schematic view showing an example of the apparatus configuration for carrying out the method of the present invention. 18 is a packed bed thickness gauge, 19 is an exhaust air temperature predicted value calculation device, 20 is a firing distance calculation device, and 21 is A baking point control calculation device, 22 is a manual setting device, 23 is a pallet speed detection adjustment device, and 24 is a main exhaust air amount detection adjustment device.

That is, in the present invention, the exhaust air temperature measured by the thermocouple 10 of each wind box 8 is input to the firing distance calculation device 20, and the firing point is detected from the transition of the exhaust air temperature. ), The average firing distance Lffp in the pallet width direction is calculated, and is output to the exhaust air temperature predicted value calculation device 19. In the exhaust air temperature predicted value calculation device 19, the above (2)
The firing distance is corrected by the equation (3) based on the exhaust air temperature predicted value calculated by the equation, and the corrected firing distance L
The ffp is output to the firing point control arithmetic unit 21.

In the firing point control computing device 21, the corrected firing distance LFfp input from the firing distance computing device 20, the firing distance target value LffpA input from the manual setting device 22,
The packed bed thickness measurement value h input from the packed bed thickness gauge 18, the pallet speed measurement value Ps input from the pallet speed detection and adjustment apparatus 23, and the main exhaust air quantity measurement value Q input from the main exhaust air quantity detection and adjustment apparatus 24 and According to the main exhaust air flow rate setting value Qs, according to the equations (5), (6), (9), and (10),
It is adjusted by giving the pallet speed Psc for obtaining the target firing distance as the set value Pss of the pallet speed detection adjusting device 23.

Example 1 The method of the present invention was actually applied to a DL type sintering machine while keeping other conditions such as the capacity of the main air exhauster constant, and the result of operation was applied only to the firing point detected from the exhaust air temperature. Table 1 shows a comparison with the conventional method in which the pallet speed is adjusted based on the above. As is clear from the results in Table 1, the method of the present invention improved the variation in the firing distance, improved productivity and yield, and stabilized quality.

[0031]

[Table 1]

[0032]

As described above, according to the method of the present invention, it is possible to dramatically stabilize the sintering in the sintering direction in the sintering machine, so that the production amount can be increased without deteriorating the yield. With this, there is a great effect that the quality can be stabilized.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram showing a relationship between a firing point in a DL type sintering machine and an exhaust air temperature of each air box.

FIG. 2 is a schematic view showing an arrangement of exhaust air temperature measuring thermocouples in a state where a part of a wind box in the same sintering machine is viewed from above.

FIG. 3 is a diagram comparing a firing point detected from an exhaust air temperature in the present invention with a predicted value of the exhaust air temperature of each air box at the firing point.

FIG. 4 is an explanatory diagram showing a relationship between a combustion speed and a pallet speed in a steady state of a DL type sintering machine.

FIG. 5 is a schematic explanatory view showing an example of a device configuration for carrying out the method of the present invention.

[Explanation of symbols]

1 Raw material charging bulk height meter 2 Surge hopper 3 Roll feeder 4 Raw material 5 Pallet crate 6 Packed bed 7 Ignition furnace 8 Wind box 9 Main blower 10 Thermocouple 12-1, 12-2 Combustion front 13-1, 13-2 Firing point 14-1, 14-2 Exhaust air temperature transition 15-1, 15-2 Exhaust air temperature rising point 18 Packed bed thickness gauge 19 Exhaust air temperature predicted value calculation device 20 Firing distance calculation device 21 Firing point control calculation device 22 Manual setting device 23 Pallet speed detection and adjustment device 24 Main exhaust air amount detection and adjustment device 25 Predicted exhaust air temperature based on the latest (current) firing point 26 Actual exhaust air temperature 27 Latest (current) firing point 28 Measured actual exhaust air temperature Burning point when the raw material of is present at the burning point position Vf Burning speed (m / min) Pf Pallet speed (m / min) h Packed bed thickness (m) Lffp Burning distance (m)

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Katsunari Hamada 4-53-3 Kitahama, Chuo-ku, Osaka City Sumitomo Metal Industries, Ltd.

Claims (2)

[Claims] 1. A firing point is detected from an exhaust air temperature of a sintering machine,
In the operating method of the sintering machine, which adjusts the pallet speed so that the detected value becomes a predetermined value, the exhaust temperature pattern is calculated from the exhaust temperature measurement value of each wind box, and the exhaust temperature pattern is the target exhaust temperature. If there is a deviation from the temperature pattern, the detected firing point is corrected using the measured exhaust air temperature pattern of each wind box and the target exhaust air temperature pattern as parameters, and the pallet speed is adjusted so that the corrected firing point becomes the target firing point. A method for operating a sintering machine, which comprises adjusting the temperature. 2. The method according to claim 1, wherein by tracking the raw material in the sintering progressing direction, the future exhaust air temperature of the raw material corresponding to the latest detected firing point is predicted, and the predicted value is used as the correction of the firing point. A method of operating a sintering machine, which is characterized by being used.