JPH089740B2 - Operating method of sintering machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for operating a sintering machine in the iron manufacturing industry.

[Prior Art] In the operation of a conventional sintering machine, the temperature distribution in the machine length direction of the temperature of the exhaust gas flowing out to the lower surface of the zone to be sintered is investigated to find the firing completion point. The line speed is adjusted so that it stays close to the place (where the ore after firing is completed is discharged from the sintering machine). FIG. 2 is a graph showing a pattern of exhaust gas temperature distribution in the machine length direction. The horizontal axis represents the machine length direction, and the vertical axis represents the exhaust gas temperature. As shown in the figure, the exhaust gas temperature keeps a constant temperature because the fuel zone is on the upper surface of the sintered zone at the beginning, and as the combustion zone approaches the lower surface, the temperature starts rising and the combustion zone reaches the lower surface. The maximum temperature is reached at the above-mentioned position, that is, at the place where the sintering is completed, and then the temperature is lowered by natural cooling. This temperature pattern differs in the width direction, and for example, the sintering end point at the widthwise center of the sintered band and the sintering end point at the widthwise end do not necessarily coincide. In Japanese Patent Publication No. 54-11763, at a specific position in the machine length direction, a plurality of exhaust gas thermometers are arranged in the width direction, and the measured value is compared with a predetermined set value, and the width direction in the raw material supply is measured. Adjust the distribution,
Uniform sintering is performed in the width direction.

[Problems to be Solved by the Invention] However, the prior art has the following problems. That is, in the conventional technique, the widthwise distribution of the exhaust gas temperature is measured at a predetermined position in the machine length direction of the sintering machine, but in the temperature pattern as shown in FIG. There is a nature. FIG. 3 is a graph showing a temperature pattern q at the center in the width direction and a temperature pattern r at the end in the width direction. It is assumed that the temperature Q at the central portion is measured at the position P in the machine length direction and the temperature R at the end portion is obtained. The point R is on the right side of the highest point of the graph, that is, the end point of sintering, but the point Q is on the left side. Therefore, comparing these values should be confused with the temperature before and after the sintering. become. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide a method of operating a sintering machine that can accurately control the sintering reaction.

[Means for Solving the Problem] While moving the above-mentioned problem in the machine length direction and the horizontal direction,
In a method for operating a sintering machine, which has a burned zone in which a combustion zone moves from an upper surface to a lower surface and has means for passing air from an upper surface to a lower surface of the sintered zone, in a width direction of a lower surface of the sintered zone. And a plurality of exhaust gas thermometers arranged in the traveling direction are used to measure the exhaust gas temperature, and an exhaust gas temperature intermediate between the temperature of the zone in which the exhaust gas temperature is kept constant and the temperature at the maximum value is designated in advance. The length in the machine length direction that gives this temperature specified value is calculated at each position in the width direction, these are used as reference lengths, and the average value of these reference lengths is calculated to obtain the reference length at each position in the width direction. And the average value of the reference length are obtained, and the widthwise charging amount of the raw material is changed by adjusting the dividing charging gates in the width direction so that these deviations become predetermined values. Solve by the operation method of the conclusion.

[Operation] The exhaust gas temperature is measured by a plurality of exhaust gas thermometers arranged in the width direction and the advancing direction of the lower surface of the zone to be sintered, and the temperature of a zone where the exhaust gas temperature is kept constant (hereinafter, initial low temperature zone) is measured. The exhaust gas temperature in the middle of the temperature at the point showing the maximum value (hereinafter referred to as the sintering end point) is set in advance as a specified value, the reference length of each width direction position that gives the specified temperature value is determined, and the reference length Obtain the average value, find the deviation between the reference length and the average value of the reference length at each position in the width direction, and adjust the widthwise divided charging gate so that this deviation becomes a predetermined value. Since the direction charging amount is changed, the position where the zone to be sintered enters the cooling state is not mistakenly recognized beyond the sintering end point.

[Embodiment] FIG. 1A is an explanatory view showing an embodiment of the present invention. The amount of the raw material 2 discharged by the hopper 1 is controlled by the charging gates 3, 31, 32, 33, 34, and the thickness of the zone 5 to be sintered is determined by the cutoff gate 4. Since the zone to be sintered is transferred by a pallet conveyor (not shown), if the thickness is constant, if the charging amount is changed, the density changes and the transfer amount changes. The charging amount is measured by the level meter 6. The zone to be sintered is ignited on its upper surface by the igniter 7, and the horizontal zone advances the sintered zone from the upper surface to the lower surface.
Before the mine is mined, the bottom surface is reached and sintering is completed. During this time, the air passes through the zone to be sintered, becomes exhaust gas, and is introduced into the wind box. The total number of wind boxes is 23. The 18th of these wind boxes,
The 20th and 22nd wind box Q ₁ (i = 18,20,22) has a thermometer
S _{i, j} (i = represents the captain direction wind box number, j represents the width direction wind box number; for example, i = 18,20,22, j = 1,2,3,4,5) ing. FIG. 1 (b) is a view on arrow AA of FIG. 1 (a). As shown in the figure, five charging gates and thermometers are arranged in the width direction. In FIG. 1, the information of the thermometer is input to the calculator 8, and the controller 9 is based on this information.
Adjust charging gate. Specify the specified values of these thermometers as X _{i, j}
(I = 18,20,22, j = 1,2,3,4,5) and the temperature distribution in the machine length direction is approximated by a quadratic curve, the temperature X _{i, j} and the length L _{j in} the machine length direction are The relationship can be expressed as in equation (1).

_{L j = A j · X i} , j 2 + B j · X i, j + C j ... (1) _{However, A j, B j, C} j is a constant. That is, this constant corresponding to each division width is obtained from the position of the thermometer and the temperature indication value. Therefore, when the temperature designated value is given to the equation (1), the length in the machine length direction can be calculated for each division width, and this is used as the reference length. It is an essential point of the present invention to control this standard and the like for each width. As the unit of length, the length of the wind box in the machine length direction was used. That is, the lengths in the machine length direction of the wind boxes 18, 20, and 22 are 18, 20, and 22, respectively, when the unit length of the box wind is 1.

Table 1 shows reference lengths corresponding to the respective division widths thus obtained. In this case, the specified temperature is 250 ° C.
In the table, the reference length corresponding to each division width is obtained from the equation (1), and the deviation from the average value is obtained. As a control policy, if this deviation is set to zero, a value obtained by subtracting each deviation from zero is input to the controller from the arithmetic unit, and the controller adjusts the charging gate.

Table 2 shows the effects of the control in Table 1,
In the method of the present invention, the production efficiency is improved as compared with the conventional method, and there is no great difference in the rotational strength (JIS M8712) of the sintered ore and the firing yield.

Table 3 shows the case where the control target value when heat recovery from exhaust gas is prioritized is set as shown in the table as a control policy, and the value obtained by subtracting the widthwise deviation of the reference length from this value is controlled by the calculator. If the control target value in the charging width direction is set as shown in Table 3 by the controller, the shrinkage due to firing of the layer to be sintered causes a gap between the side wall and the firing layer in the width direction. Since the positions of the sintering completion points at both ends can be moved backward and the amount of sucked in cold air can be suppressed, the temperature of the exhaust gas can be raised to a high temperature.

Table 4 shows the effects of the control in Table 3,
Compared with the conventional method, in the method of the present invention, the recovery amount of steam generated by heat recovery of exhaust gas is improved.

As described above, in the present invention, the distribution of the reference length in the width direction can be changed according to the control policy.

[Effect of the Invention] As described above, in the present invention, by controlling the reference length distribution in the width direction, the efficiency of the sintering machine is improved, the quality is ensured, and the heat recovery is efficiently performed. is there.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the present invention, FIG. 2 is a graph showing a pattern of exhaust gas temperature distribution in the machine length direction, and FIG.
The figure is a graph showing a temperature pattern q at the center in the width direction and a temperature pattern r at the ends in the width direction. 1 ... Hopper, 2 ... Raw material, 3, 31, 32, 33, 34 ...
Charge gate, 4 ... Cut-off gate, 5 ... Sintered zone, 6 ... Level meter, 7 ... Ignition device, 8 ... Computing unit, 9 ... Controller, S _{i, j} (i = 18,20,22, j = 1,2,3,4,
5) ... thermometer, Q _i (i = 18, 20, 22) ... wind box.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Fukuyo 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Takashi Wada 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Asahi Nakamura Examiner, Nihon Kokan Co., Ltd.

Claims (1)

[Claims] 1. A sintered zone in which a combustion zone moves from an upper surface to a lower surface while moving in the machine direction and a horizontal direction, and means for ventilating air from the upper surface to the lower surface of the sintered zone. In the operating method of the sintering machine, the exhaust gas temperature is measured by a plurality of exhaust gas thermometers arranged in the width direction and the traveling direction of the lower surface of the zone to be sintered, and the temperature of the zone where the exhaust gas temperature is kept constant and the maximum The exhaust gas temperature in the middle of the temperature at the point indicating the value is set in advance as a specified value, and the length in the machine length direction that gives the specified temperature value is calculated at each position in the width direction. Obtain the average value of the lengths, find the deviation between the reference length at each position in the width direction and the average value of the reference lengths, and adjust the widthwise divided charging gate so that the deviation becomes a predetermined value. Sintering characterized by changing the widthwise charging amount of The method of operation.