JPS6126731A - Method for measuring heat pattern during sintering - Google Patents

Abstract

PURPOSE:To obtain heat history during sintering by on-line measurement in a sintering process in a Dwight-Lloyd sintering apparatus by measuring a change in the surface position of a sintering bed in the direction of the height and estimating the position of the flame front at an arbitrary position. CONSTITUTION:In a sintering process in a Dwight-Lloyd sintering apparatus 1, a change in the surface position of a sintering bed 4' in the direction of the height is measured. A point D at which the height of the bed 4' is fixed in the ore discharge part is considered to be a position D at which the heat front HF reaches the surface of the grate. The heat front HF in the range from a position B at which the bed 4' is fired to the position D at which the heat front HF reaches the surface of the grate is estimated from the surface position of the bed 4'.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a method for measuring a heat pattern (thermal history) in a sintered layer of a Dwight Lloyd sintering machine for producing sintered ore as a blast furnace raw material. It is something.

[Prior art]

In general, the sintering heat pattern in the sintering process controls the quality and productivity of sintered ore, and its measurement is extremely important.

Therefore, various heat pattern measurement methods have been proposed in the past.

(2) A method of inserting a thermometer directly into the layer of the sintering machine and measuring the heat pattern.

(3) Method 1 of measuring the wind speed distribution in the lengthwise direction of the sintering machine and estimating the red heat necessity position by assuming that the heat front speed is proportional to the wind speed. (4) Cross section of the sinter cake in the sintering machine discharge section There are methods such as measuring the width of the red-hot layer zone and estimating the heat-behind position.

However, all of these conventional methods are insufficient for estimating the heat front position at any location in the sintering machine. That is, with method (1), no information in the longitudinal direction of the sintering machine can be obtained. The only information available is where the frame front reaches the grate surface of the sintering machine. Method (2) can only obtain information on the position of a few sintering points, and method (3) cannot accurately measure the wind speed passing through the sintering bed.The life of the thermocouple as a sensor is short. It is not easy to estimate the position of the heat front, and the accuracy of estimating the rotational speed is not good.

The method (4) has its own problems, such as not being able to obtain information in the machine length direction of the sintering machine.

[Summary of the invention]

The present invention was made in order to solve the problems in the conventional method as described above.The present invention has been made to measure the frame front position at any position of the Dwight Lloyd type sintering machine and measure the sintering heat pattern. This is the purpose.

The present inventors discovered that in the sintering process, most of the shrinkage of the sintering bed occurs during the process of melting and shrinking of the sintering raw material, which led to the present invention. Contraction behavior of tied bed (bed surface position &:
This figure shows the relationship between I), exhaust gas temperature (II), and exhaust gas air volume (2). After the sintering bed (the frontmost part in contact with the sintering part) reaches the grate surface (the surface of the sintering bed tY), the shrinkage does not proceed and becomes constant. In this case, the rearrangement of the raw material filling or the change in the position of the sintering bed surface is small compared to the shrinkage during melting and shrinkage and can be ignored.

Furthermore, Figure 2 shows the suction negative pressure as A ('-1300m)B (
-1100 degrees) C (-'800 degrees) This shows the shrinkage behavior of the bed surface position when changing K. This was done based on the knowledge of the contraction of these sintered beds. In the sintering process of the Dwight Lloyd sintering machine, the present invention measures the change in the height direction of the surface position of the sintering head of the sintering machine, and determines the position where the height change in the ore discharge area has disappeared. This is a sintering heat pattern measurement method characterized by estimating the heat front from the ignition start position of the sintering bed to the position where the heat front reaches the grate surface from the surface position, with the grate surface arrival position of the heat 7Cy/t. 0 Next, the present invention will be described based on examples.〇 [Example] FIG. 3 is a schematic diagram for explaining the heat pattern measurement method of the present invention.

In FIG. 3, reference numeral 1' denotes a sintering machine, a pallet body in which a plurality of pallets constituting the main body of the two-piece sintering machine are connected in a two-piece manner, and the pallet 2 moves in the direction of the arrow in the figure. 3
4 is a raw material charging hopper, 4 is a raw material, and 5 is a cut plate for making the raw material into a constant thickness.The raw material 4 is formed into a sintered bed 41 with a constant thickness on the grate of the pallet 2 by the cut plate 5. Numeral 6 is an ignition furnace, 6a is an ignition furnace burner, and 7 is arranged inside the pallet body 2, including immediately below the ignition furnace 6, and along the length of the machine on the downstream side thereof.

With this configuration, the surface of the sintering bed 4I on the grate of the pallet 2 being moved is ignited at position B directly below the ignition furnace, and as the pallet 2 is being moved, the surface of the sintering bed 4I on the grate is ignited, and as the pallet 2 is being moved, the wind box 7
The sintering bed 4r is
By sucking more air downward, the raw material on the grate is sintered and melted, falls from the ore discharge section at the most downstream of the sintering machine, and is then crushed by a crusher (not shown); then sieved, It is recovered as finished sintered ore.

The position of the surface of the sintering ped 4I in the longitudinal direction of the sintering machine is detected, and the position at which there is no change in the position of the ore discharge part is determined as the position where the heat front HF reaches the grate surface, and the ignition position 1B', The position of the heat front is defined as the starting position of descent of the heat front, and the intermediate heat front position (height from the HP nigerate surface) is the surface height of the bed 42 during sintering) II.
It is calculated from the following formula.

However, Ho is the surface position of the sintering bed at the time of ignition He is the surface position when the heat front is reached, that is, the layer thickness from the surface of the sintering bed 4I to the grate as the sintering machine moves as shown in FIG. Ho −+ H
It contracts as i −+ He. From this, HF is determined using the above formula.

The heat-behind (HB) position is the x'rvs and Img for imaging the red tropical position of the ore dumping area.
Once detected by the processing device 9, calculation can be made in proportion to the change in the heat front position.

For surface position detection, as shown in FIG. 4, the layer thickness of the sintering bed 4I can be measured in the machine length direction using a position detector 10 sliding on the surface of the sintering bed 4I. Note 1
1 is a fixed channel of the position detector 10.

FIG. 5 is a diagram showing another embodiment for surface position detection.

That is, in FIG. 5, a surface position meter 10' is fixed to the channel 11 of the pallet 2, and the layer thickness is measured by sliding the surface of the sintering bed 4' in the longitudinal direction as the pallet moves. .

〔Effect of the invention〕

The heat pattern measurement method according to the present invention is a simple method for estimating and measuring the frame front position at an arbitrary position in the machine length direction of the sintering machine, and obtains an on-line sintering heat pattern, thereby obtaining information that is effective as sintering process information. This is a very useful method.

[Brief explanation of drawings]

Figure 1 is a graph showing the relationship between the shrinkage behavior of the surface of the sintering bed and the exhaust gas temperature and exhaust gas flow rate. Figure 2 is a graph showing the shrinkage behavior of the sintering bed surface when the negative pressure is changed. FIG. 3 is a schematic diagram for explaining the present invention in detail, and FIG.
5 and 5 are explanatory diagrams of the surface position detection method, respectively. Note that the same reference numerals in each figure indicate the same or the same functions. 1-#-sintering machine, 2...pallet, 4...raw material 4
/... Sintering bed °, 6... Ignition furnace, 7... Wind box, 8... ITV9... Image processor, 10.10'
...Surface position needle agent Patent attorney Sanro Kimura Figure 1 Figure 2 Figure 1 Boundary hour leap 1rnll+summer

Claims (1)

[Claims] In the sintering process of the Dwight Lloyd sintering machine, measuring the change in the height direction of the surface position of the sintering bed of the sintering machine,
The position where there is no change in height at the ore discharge section is defined as the position where the heat front reaches the grate surface, and the heat front from the ignition start position of the sintered bed to the position where the heat front reaches the grate surface is estimated from the surface position. A sintering heat pattern measurement method characterized by: