JPS5920736B2 - Method for detecting sintering progress inside the sintered layer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting the progress of sintering inside a sintered layer on a pallet of a biwitroid sintering machine, and more specifically, the present invention relates to a method for detecting the progress of sintering inside a sintered layer on a pallet of a biwitroid sintering machine, and more specifically, the distribution shape of the combustion zone in the longitudinal direction of the sintering machine and the ventilation resistance index. This relates to a method of providing operational information such as.

The inside of the sintered layer in the DL sintering machine is as shown in Figure 1.
It consists of a raw material zone 1 which is an unsintered part, a combustion zone 2 where coke combustion and ore melting are occurring, and a sintered zone 3 where sintering is completed.

The distribution shape of combustion zone 2 in the longitudinal direction and its ventilation resistance index are:
Each shows the progress of sintering, the combustion effect of coke, and the melting state of ore, which are important factors in sintering operations.

In other words, when the sintering of the sintered layer progresses and it is discharged from the pallet, the combustion must be almost complete and the sintering must be completed. It is not possible to accurately judge from observation alone whether or not the progress of combustion inside the subsequent sintered layer, that is, the progress of ignition of raw materials and combustion in the sintering process, is appropriate.

Therefore, the amount of coke in the charge on the pallet,
In order to know whether the raw material mixture, amount of water added, etc. are appropriate, it is important to accurately understand the distribution shape of the combustion zone in the longitudinal direction and the ventilation resistance index.

Generally, the distribution shape of the combustion zone in the sintered layer is estimated by embedding several thermocouples in the height direction within the sintered layer and measuring the temperature change as the pallet advances. @) Temperature measurement location or local.

(b) The lifespan of thermocouples is very short, about 1 to 2 days, and cannot be measured continuously.

(c) It is necessary to stop the sintering machine when attaching and detaching the thermocouple.

There are many problems with thermocouple measurements, and this is only being done on a trial basis.

On the other hand, the measured value of the ventilation resistance index in the raw material zone is often reported because it is easy to measure.
It was not possible to measure the combustion zone directly because the temperature was so high that it was difficult to grasp and identify the exact location of the combustion zone during operation.

The sintering models that have been published to date try to faithfully represent the reactions within the sintered layer, so they have too many parameters and the model formulas themselves are complicated, so they have not been applied to actual operations. Therefore, proposals are being made for methods that can accurately determine the progress of sintering inside the sintered layer using a sintering model that can actually be applied to sintering operations.

The present invention has responded to such demands in the technical field and proposed a method for determining the progress state of sintering inside the sintered layer. It is designed to be applicable to operations.

In other words, the gist is that the wind speed measurements obtained by installing anemometers at four or more locations in the machine length direction on the wind box part of the sintering machine or on the top surface of the sintered layer, along with the suction negative pressure and pallet speed layer thickness, are applied to the sintering model. The system continuously detects the input combustion zone distribution shape in the longitudinal direction of the machine, the ventilation resistance index of the raw material zone and the combustion zone, and the wind speed distribution in the longitudinal direction, and provides the information to operators as daily operation information.

Next, the method of the present invention will be explained in detail.

The flow of the sintering model of the present invention is as follows.

(1) Derivation of the wind speed distribution function according to the present invention in the longitudinal direction of the sintering machine.

(11) Derive the ventilation/resistance index of the raw material zone and combustion zone, which are the constituent parameters of the wind speed distribution function, from the wind speed measurements at four points in the longitudinal direction of the aircraft.

An outline of the sintered model of the present invention is shown below.

As shown in Figure 1, the sintered layer consists of a raw material zone 1, a combustion zone 2,
The airflow resistance index is defined as the following equation (g).

R=JP/ΔH/Qn --------(]) Also yB/VF-KB/KF...
・(2) dyB/dx=KB −Q/PS ・・・・・
-(3) The following equation (4) is obtained from the above equation (1).

yB'R8HO+(yF yB)・RNEN+(
HYv)・F? Gwn-ΔP/Q0...
...(4) Substituting equations (2) and (4) above into equation (3) and solving the following HFP 4. HBP
A distribution function of 5 and a wind speed distribution function in the longitudinal direction of the sintering machine are obtained.

Additionally, empirically, ΔP/ΔH-RQ 1゛4 (n = 1.
4) is said to hold true, and also in actual operation of a sintering machine, n=1. ．． Since it has been confirmed that the case of 4 is actually encoded best, a solution of n-14 will be shown below.

Equation (4) is obtained from Equation (1), and by substituting Equation (2) and (4) into Equation (3) and solving, the following HFP 4 is obtained.
．． The distribution function of HBP 5 and the wind speed distribution function in the longitudinal direction of the sintering machine are obtained.

When X≦Lo■-yB'KF/KB ・・・・・・
...(6) XL.

Then, B=H' Rcgrq ・--(13)C2R8
HORNE N”-・(14) D=H-RNF, N
・・・・・・・・・・・・(15) yB: Distance from the sintered layer surface to HBP 5 (m) yF: Distance from the sintered layer surface to HFP 4 (m) Q: Sintered layer Passing wind speed (m/min) PS: Pallet speed (m/m1n) ΔP: Negative suction pressure (rnmH20) Thickness (m) RGF, N' Airflow resistance index of raw material zone (mIIIH20・
min'°4/m2°4) RNEN' Airflow resistance index of the combustion zone R8HO: Airflow resistance index of the sintered zone KF: Wind speed coefficient of HFP 4 KB: Wind speed coefficient of HBP 5 Lo: HFP 4 and the lower surface of the sintered layer This shows the distance (m) at the intersection point 1 with .

Furthermore, the following equation (16) holds true as an empirical equation.

R5Ho =RNEN/20 -・------(
16) From the above explanation, the following can be said.

(7L The wind speed distribution function passing through the sintered layer in equation (9) is R6°,
.

It consists of five unknowns: RNF, N, R8HO'KF' KB, and by substituting the measured wind speed values at two points each into (7) and (9X), a five-element simultaneous equation is obtained along with equation (16), By solving this, we can derive all the unknowns.

This makes it possible to estimate the distribution shape of the combustion zone in the longitudinal direction and the wind speed distribution in the longitudinal direction.

FIG. 2 shows a comparison between the distribution shape of the combustion zone 2 obtained by the method of the present invention and the in-bed temperature distribution 9 actually measured by a thermocouple.

The graphs a and b of the temperature distribution in the layer 9 were measured at two locations, 10 CrrL and 20 cIrL, respectively, from the bottom of the sintered layer, and the movement path of the thermoelectric lamp is shown by a solid line on the combustion zone distribution map.

The actually measured high-temperature portion of the temperature distribution in the layer and the position and shape of the combustion zone 2 show relatively good agreement.

Next, examples of the method of the present invention will be described.

Sintering factory A, 3.7, 10.13 Wind box 7
A Venturi airflow meter is installed in each of the wind legs 8 (see Figure 1), and the wind speed measurements obtained at the four points are input into the computer along with the suction negative pressure, pallet speed, and layer thickness, as shown in Figure 3. Combustion zone distribution map and wind speed distribution map 1
0, the ventilation resistance index of raw material zone 1, the ventilation resistance index of combustion zone 2, etc. are displayed on the CRT screen.

This allows operators to constantly monitor the progress of sintering inside the sintered layer.

As a result, if an abnormality is observed on the CRT screen showing the sintering progress, it is possible to immediately take measures such as adjusting the amount of water added to the raw material or the amount of coke, and any changes that appear in the sintered model can be taken. It has now become possible to accurately determine the cause and countermeasures and implement them.

The marks in the same wind speed distribution map 10 indicate the measured wind speed values,
A curve connecting these landmarks is a wind speed (air volume) distribution curve detected by the method of the present invention.

According to the present invention, it has become possible to continuously detect the distribution shape of the combustion zone in the longitudinal direction, the ventilation resistance index of the raw material zone and the combustion zone, and the wind speed distribution in the longitudinal direction and provide them as operational information.

It goes without saying that this provision of information is applied not only to daily operations, but also when determining or changing conditions by examining the overall operating conditions of the DL sintering machine.

The fact that the sintering conditions can be adjusted accurately based on this information is remarkable.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram showing the composition of the raw material zone, combustion zone, and sintering zone in the sintered layer, and Figure 2 is the combustion zone distribution shape estimated by the present invention and the actual temperature inside the sintered layer measured by a thermocouple. FIG. 3 is a drawing showing the relationship with the distribution, and is a drawing showing an example of displaying various information obtained by the present invention on a CRT screen. 1... Raw material zone, 2... Combustion zone, 3... Sintering zone, 4
... HFP, 5... HBP, 6... Ignition furnace, 7... Wind box, 8... Wind leg, 9... Actual temperature distribution in the layer, 10... Wind speed distribution map.

Claims (1)

[Claims] 1. Wind speed measurements and pallet speed obtained from anemometers installed at four or more locations in the machine length direction on the wind box part of the Dwight Lloyd sintering machine or on the top surface of the sintering machine,
The layer thickness and suction wind pressure are input into the sintering model and calculated, and the ventilation resistance index of the raw material zone and combustion zone inside the sintered layer, the suction wind speed distribution in the longitudinal direction of the sintering machine, and the longitudinal direction of the combustion zone are calculated. A method for detecting the progress of sintering inside a sintered layer, which is characterized by continuously detecting the distribution shape.