JPS5839749A - Operating method for dl sintering machine - Google Patents

Abstract

PURPOSE:To effectively control the operation of a DL sintering machine by measuring the amount of air passed through a layer during sintering on the pallet in the longitudinal direction with a measuring device installed movably over the layer and by estimating the distribution of a red-hot zone in accordance with the measured amount of air. CONSTITUTION:A measuring device 12 for the amount of passed air supports a wind box 14 by means of a carriage 13 which moves in the moving direction of a pallet 7 and can be lifted up and down. While moving the carriage 13, the amount of air sucked in a layer 15 during sintering, that is, the amount of air passed through the layer is obtd. from the speed of sucked air flowing through the wind box 14. The distribution of a red-hot zone in the layer can be estimated from the distribution of the amount of passed air obtd. by the measurement. The average high temp. holding time is calculated according to the distribution of the red-hot zone, and the sintering machine is controlled so as to regulate the holding time to a set proper value range obtd. from the quality of a product.

Description

[Detailed description of the invention] This invention relates to a method of operating a DL type sintering machine,
In particular, by measuring the air volume during sintering and passing through, which sensitively reflects the sintering process, we can estimate the red tropical distribution based on the measured air volume, and based on this estimate, we can ensure stable sintered ore quality. This is a proposal for a method of operating a sintering machine that is distinctive in that it is controlled.

In general sintering equipment, after charging coke powder and ore powder onto a pallet using a raw material charging device, the surface of the charged raw material 1- is ignited, and as sintering progresses from the upper layer to the lower layer. ,
The pallet is directed toward the ore discharge section, and at the same time as the pallet is ignited, a wind box and main exhaust fan valve are used from below the pallet to suck the air passing through the raw material layer. Drying, combustion, and combustion of coke
After the process of sintering and cooling, agglomerated sintered ore is produced. This process will be explained using diagram #c1.
Raw materials such as fine ore, coke, and limestone cut from In! After passing through the merrick 2 and being injected and mixed by the mixer 3, the ore is stored in the feed hopper 1, and then charged onto the pallet 7 by the feeder 6. The coke in the raw material l- charged on the pallet 7 is ignited by the ignition furnace l to burn it and burn the fine ore. On the other hand, there are wind boxes lO1 to 10n under the pallet 7, which are connected to the main blower. // is connected to b. This main pool a~l/
Since air is sucked downward through the raw material layer, red-hot zone (FFP) %1i%m progresses sequentially from the upper layer to the lower layer of the fine raw material layer, and when it reaches the ore discharge area for 1 year, it is fired. is now complete.

The operation of the sintering machine is carried out by detecting the point BTP at which sintering is completed by measuring 1 Mf of exhaust gas with a thermocouple installed in the wind box or from the value of 1 Mf of exhaust gas, and then determining the point BTP at which sintering is completed.
Pallet speed, sintered layer thickness,
It is controlled by adjusting the opening and opening of the main blower suction damper. When such conventional control methods are adopted, the quality of the produced sintered ore can only be detected by sampling the sintered ore after production. Delays are a major problem.

As explained above, sintering agglomeration, drying, combustion, sintering,
The cooling ring process is carried out, and if the sintered layer on the pallet 7 is roughly divided into a raw material zone, a red zone, and a sintering completion zone, the residence time of the raw material in the red zone during the completion of these zones is as follows: That is, it is known that the time during which the coke is kept at a high temperature during coke combustion does not have a significant effect on the quality of the sintered mineral product. Therefore, by adjusting the above-mentioned high temperature holding time, it becomes possible to control the quality of the sintered ore product during the manufacturing process. However, conventional methods for directly controlling the high temperature holding time have not been used.

It is t that measures the high temperature holding time in the actual machine.
(This was because there was no other suitable measurement method other than inserting a thermocouple directly into the sintered layer, and it was considered impossible due to the difficulty of maintaining the thermocouple.

In addition, the coke sintering rate and cooling rate in the sintered layer are td
It is also a well-known fact that the rate of air passing through the layer is limited and has a great effect on the quality and productivity of sintered ore. In this sense, if the amount of air passing through the layer during the sintering process can be detected, the situation within the layer can be detected.

This invention is a method developed to solve the above-mentioned problem of the prior art, and by measuring the amount of air passing through the sintered layer, the red heat distribution is estimated, and each sintered raw material is exposed to red heat. By appropriately controlling the residence time in the zone, a predetermined quality of sintered ore was obtained, and sintered ore of stable quality was ensured. The configuration of the present invention will be described in detail below in conjunction with the explanation of the drawings.

Figure 2 of the drawings shows the I passing through the layer during the sintering operation process.
This figure shows an outline of a device that continuously measures L in the machine length direction.This passing air flow measurement device is made by TL Co., Ltd., and is made by supporting a wind box L on a trolley/J that is transferred in the direction of pallet 7 movement. This trolley/Jti moves up and down as well as reciprocates in the longitudinal direction of the pallet 7, and during this movement, sintering rd/! According to this device, the amount of air passing through the layer in the longitudinal direction of the sintering machine (the amount of air passing through the layer in the longitudinal direction of the sintering machine) is Figure 3-(a') shows an example of measurement taken using the above-mentioned air volume measuring device. A plot of measured values and an approximate curve thereof are shown.

This measured passing air volume value is the sintered layer l! It depends on the ventilation resistance inside. Therefore, from the passing air volume distribution obtained by the measurement, the red tropical distribution within the layer in the longitudinal direction of the sintering machine can be determined by using the ventilation resistance index of each sintered zone and the passing air volume index.

The first feature of this invention lies in estimating the distribution of the red tropics from this wind volume.

The method of estimating the red tropical distribution from the passing air volume adopted in the present invention will be described below. Now, as shown in Figure 6 inside the sintered j-, the combustion front (R
FP) 5F and m before sintering (HBP) If the point where the edge intersects with the pallet surface is RFP, then equations (1) to (5) hold true, and the width of each plane is Δλ)
1. R2H3 is calculated by the following formula (
4), (5), and (6).

In other words, the pressure loss of the sintered layer is proportional to the exponential power of the passing air volume, and the pressure loss at any position is expressed by the following formula: α ΔP = (R, H, + R2H2 + R, H,) G
Also, the no thickness is expressed by the following formula: H#+H2+Hs(2) RFP height.

From the above formulas (1) to (5), the heights H1 to H3 of each sintered zone are expressed by the following formula.

F(,=H-Hl-)(2(d) H: Layer thickness (rrL) ΔP: Suction negative pressure (VWL2) in the captain's direction
: Suction air volume at any point in the longitudinal direction (Iw/2.□1o)
θ: Elapsed time from the ore feed end (mini R1 to R5: more than the pressure loss resistance coefficient of the raw material zone, red tropical zone, and instant bonding completion zone), wind M(), wind box pressure ΔP% layer thickness l (, HFPo, the point where the clam ware front (HFP) intersects with the pallet surface.

Ventilation resistance coefficient hole in each zone, ~R5, and 4% wind passing through the layer
If the index α is determined, it is possible to estimate the red tropical distribution in the longitudinal direction of the sintering machine.

In this respect, it is possible to detect IjT by the change in exhaust gas m1ff measured by each RFPolfi window box. That is, each wind box 1
0. When measuring the exhaust gas temperature with thermocouples installed every ~10n, the exhaust gas temperature remains approximately constant until H1'P reaches the pallet surface. By performing correction using , it is possible to reduce R.

HFPo of this invention is tlc41! As shown in the figure, the point at which the temperature reaches 100°C is detected from the exhaust gas @ temperature pattern measured by the wind box IO1~1Otl, the time from the feed end to reach that point is determined, and the value at that value is determined. The added value was defined as HFPo. The value to be added here (θT
) is determined by the consistency of the temperature in the red tropics, and is determined in advance from the results obtained by inserting a thermocouple into the sintered layer II and measuring the tort pattern. For example, it has been confirmed that the temperature in the layer during the heating process increases approximately linearly as shown in Fig. A specific example of the present invention in which the red tropical izb distribution is estimated from the passing air volume distribution using equations (4) to (6) in the 0th order where rmln is adopted as θ1 is shown below.
It is shown in IJ diagram false 1. This figure shows the red tropical l9 distribution calculated using the approximate curve of the passing air volume distribution corresponding to Fig. 3-(1). The shaded box in the figure represents the Red Tropical/jb distribution obtained from the simultaneously measured sheet pattern.
The two companies agree well, demonstrating the validity of the Red Tropical distribution model of the present invention. In short, by using Figure 3-(b), the Red Tropical region izb can be adjusted to any sintered layer height. By cutting at , the cut line segment is the pot temperature retention time at that height. That is, the average high temperature retention time can be determined from the red zone width (H2) at any position of the flash setting strand using the following equation.

Here, HT: average high temperature holding time (plin) H: sintering j-
Thickness 071) H2: Red zone width (fi) θ: Elapsed time from the strand feeding end (minl) There is a correlation between this HT and the strength of the sintered ore product (8I) as shown in Figure 7. There is also a correlation between pallet speed and coke placement ratio as shown in Figure 1.Therefore, based on operational experience, an appropriate HT value that guarantees the target sintered ore product strength (sr) is observed. W shown in Fig. 7 is set in advance, and the average high temperature holding time HT obtained by calculating from the koji filtration amount distribution obtained as described above is calculated, and the pallet speed is adjusted so that it falls within the range of the set value. etc., if you control it,
Local supply ore of specified quality can be obtained. Figure 2 is a diagram of the control flow.

As shown in FIG. 1, this control method uses data obtained from the air volume measuring device and each wind box 10. ~lO
The red tropical distribution is estimated from the temperature of n, and the average high temperature retention time is determined. By comparing the obtained average high-temperature retention time with a high-temperature retention time in an appropriate range set in advance, it is possible to determine whether or not to take an action and control the process.

Note that the combustion front HFP can be not only a straight line but also a curved line depending on the amount of passing air. In addition, the ventilation resistance index R1 to approximately 5 of each zone may be determined by the index α x m of the passing wind cover, or it may be determined by calculation, but in the actual example of the present invention, the basic formula is A P/H = Using RO, we calculated the pressure loss formula at several points along the length of the aircraft.

Example: Ordinary sintering raw material (coke-containing bell, rose, water content: 6%)
Use layer thickness! 30 mm, for bullet speed, 7
Sintering operation was started at m/min. During this sintering operation, after the ignition furnace, the amount of suction was measured by running a suction device that passed through the bed in the discharge direction.

At this time, HFPo was the sintering machine manager Nakataka! Since an increase in exhaust gas @ temperature was detected at the thermocouple part located in the wind box, the red tropical boundary temperature was set to 1000°C, and correction was made to θ,♂min.

Wind box pressure Δ corresponding to the measurement time of the above passing airflow measuring device
P is 11130mt'ILH20, and its value and each air permeability of the sintered layer R4 to R5, here each 1 determined by the pot test.
．． 61. H2f using the value of J da, j6.3.0 hiro
, Numbness, -8 Self The average high temperature holding time HT determined by the pallet speed is ko,! It was min. Since we were aiming for a sintered product quality SI of 9% or higher, we decided to change the pallet speed to 2.3 m/min and carry out the sintering operation based on the relationship between Figures 7 and 1. Quality of the product obtained in 1. I am very disappointed, and it was exactly as I expected.

As described above, according to the present invention, the following effects can be expected. In other words, the quality of sintered ore can be estimated online and appropriate actions can be taken quickly, reducing the variation in sintered ore quality and making it possible to obtain high-quality sintered ore.

[Brief explanation of the drawing]

Figure 7 of the drawings is a route map of the sintering equipment, Figure 1 is a perspective view of the air flow measuring device passing through the layer, and Figure 3 is the distribution of suction air volume (passing air volume) in the longitudinal direction of the sintering machine (,) and its distribution. A line diagram showing the distribution of the red tropics (b) estimated from the distribution, Figure V is the exhaust gas temperature distribution diagram, Figure ! Figure 84 is a diagram showing the relationship between each zone boundary temperature and correction coefficient θ, Figure 84 is a diagram of the sintered layer division model, and Figure 7 is the relationship between high temperature holding time (HT) and product strength 8I. Figure F is a diagram showing the relationship between pallet speed and average high temperature holding time, and Figure F is a control flow diagram of an embodiment of the present invention.

Claims (1)

[Claims] 1. Measure the airflow passing through the sintered layer in the longitudinal direction using an airflow measuring device movably installed on the sintered layer of the pallet, and estimate the Red Tropical distribution within the sintered layer from the measured airflow passing through the layer. Then, the average high temperature retention time is calculated based on the estimated red tropical distribution, and the sintering machine is controlled so that the average high temperature retention time is within a preset appropriate value range determined from the product quality. Characteristics of DI and sintering machine operating methods.