JPS62170427A - Sintering method and vertical type sintering machine - Google Patents

Abstract

PURPOSE:To increase a sintering speed and to improve productivity by periodically changing the blast quantity per unit time of the sintering air to be supplied to the sintering raw material layer of a sintering machine body and supplying the sintering air in a pulsation state. CONSTITUTION:A program to periodically change the flow rate of the exhaust gas per unit time to be discharged by a main discharge pipe 21 (hence the blast quantity of the air to be sucked by a main air feed pipe 29) at a prescribed pattern is set in a programmer 34. The program is so set that the blast quantity is changed from the max. value V1 to the min. value V2 by periodically changing the opening degree of a flow rate regulating valve 25 at a period T and that the average value V0 thereof is made slightly larger than the limit air flow rate when the raw material layer begins to generate a fluid state. The period T is preferably set at about 20-30sec at the max. and about 1sec at the min. The productivity is thereby made higher than in the conventional case in which the air is blasted at a constant flow rate.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a sintering method and a vertical sintering machine for producing bulk sintered ore by sintering powdered ore.

"Prior Art" When producing sintered ore for blast furnaces by sintering powdered ore, for example, powdered iron ore, a vertical sinter 11B as shown in FIG. 4 is conventionally often used.

This conventional vertical sintering machine B consists of a sintering machine main body l, a charging device 2
, a crushing device 3, an air pipe 19, and a blower device 4 are the main components. The sintering machine main body l contains powdered sintering raw material 5.
An ignition device 7 is placed in the raw material layer 6 formed by filling the inside of the raw material layer 6.
．． 7 to ignite and sinter continuously. That is, once the raw material layer 6 is ignited, sintering using it as a fire source proceeds continuously at a position directly above the ignition devices 7, 7, and a sintered zone 8 is formed there. By crushing and taking out the sintered zone 9 in which sintering has already been completed at the bottom of the zone 8, the raw material layer 6 is continuously sintered while falling at a predetermined speed due to gravity. It has become.

The crushing device 3 crushes the lower part of the sintered zone 9 using hammers 11, 11 that reciprocate from side to side in FIG. The bread falls inside and is taken out by a bread conveyor 14. In addition, the charging device 2
The raw material 5 stored in the raw material hopper 15.
16 so that it is supplied into the sintering machine main body l.

Further, the blower device 4 is configured to discharge exhaust gas generated during sintering and to supply a predetermined amount of sintering air to the raw material layer 6.

That is, this blower device 4 directs exhaust gas to suction ports 17 and 17 provided on the side surfaces 1a and 1a of the sintering machine main body 1.
Therefore, the air is sucked and discharged through exhaust pipes 18, 18 by an exhaust fan (path shown). Along with the suction of the exhaust gas, sintering air is suctioned from air pipes 19 and 19 provided at the bottom of the product cooling hopper 13. In addition, there is a grate 2 in front of the suction port 17.17.
0.20 is attached.

The air for sintering sucked in by this blower device 4 first cools the finished product 12, and then passes through the sintering completion zone 9 and is also cooled before being guided to the sintering zone 8, so that the sintering air itself The temperature is raised, sintering is performed efficiently, and heat is recovered.

"Problems to be Solved by the Invention" By the way, when using the above-mentioned conventional vertical sintered fiB, its productivity, that is, the speed at which the raw material layer 6 is sintered depends on the speed at which the raw material layer 6 is supplied to the sintering zone 8 by the blower 4. It depends on the amount of sintering air blown, and the larger the amount of sintering air, the higher the sintering speed can be. Therefore, it is desirable to increase the amount of air blown as much as possible, that is, to make the speed of air blown as fast as possible, but in the past, it has been difficult to significantly improve productivity because of the problems described below.

That is, as shown in FIG. 5(A), when the sintering air is supplied at a predetermined air flow rate, that is, at a predetermined wind speed V, the sintering air smoothly flows through the sintering completion zone 9 and the sintering completion zone 9. Obi 8,
The sintering air passes through the raw material layer 6 and is discharged from the suction port 17.17. From this state, if the wind speed V is increased to increase the amount of air blown, as shown in Figure 5 (b), the sintering air A vortex is generated in the raw material layer 6, particularly at the corners, and the particles of the sintered raw material 5 in that portion are rotated by the vortex, resulting in a so-called fluid state. When the wind speed V is further increased, as shown in FIG.
and peel off, resulting in what is called a hanging condition.

If sintering is continued in such a fluidized state or suspended state, the continuity of sintering will stop and the operation will become unstable. In addition, the quality of the finished product would also deteriorate, so in the past, air was only supplied at an upper limit wind speed that would prevent the raw material layer 6 from becoming fluid, and therefore no further improvement in productivity could be expected. Met.

This invention was made in view of the above circumstances, and the purpose is to provide a sintering method and a vertical sintering machine that can further improve productivity without reducing the quality of finished products. do.

[Means for solving the problem] The sintering method of the first invention includes periodically changing the amount of sintering air blown per unit time when supplying sintering air to the raw material layer. The sintering air is supplied in a pulsating manner.

Further, the vertical sintering machine of the second invention includes a sintering machine main body that sinters a raw material layer made of powdered sintering raw material formed inside while moving downward, and a sintering machine body that sinters the raw material layer formed inside the raw material layer. A blower device for supplying air for sintering and passing the sintering air from below to above the raw material layer, and discharging exhaust gas generated during sintering; In a vertical sintering machine equipped with a charging device that charges raw materials to form the raw material layer and a crushing device that crushes the sintered product, the blower device is configured to supply a sintering device to the raw material layer. The sintering device is characterized in that it includes a blowing amount adjustment mechanism that adjusts the blowing amount of air, and a control mechanism that brings the sintering air into a pulsating state by controlling the blowing amount adjusting mechanism.

"Function" In the sintering method of the first invention, by periodically changing the amount of sintering air blown per unit time and blowing in a pulsating state, the sintering method is sufficient when the amount of sintering air is large, that is, when the wind speed is high. sintering is promoted, and the flow state of the raw material layer or the hanging state of the sintered zone that occurs at that time is eliminated when the amount of air blown is small, that is, when the wind speed is slow.

Further, in the vertical sintering machine of the second aspect of the invention, the control mechanism controls the blower 1111 adjustment mechanism to change the blowing amount of the sintering air at a predetermined period to create a pulsating state.

``Example'' Hereinafter, an example of the present invention will be described with reference to the drawings.

First, the vertical sintering machine A of this embodiment will be explained with reference to FIG. This vertical sintering machine A has the same structure as the conventional vertical sintering machine B described above except for the blower, so the same components are indicated by the same symbols in FIG. 1 as in FIG. 4. The explanation will be omitted.

FIG. 1 is a system diagram showing the configuration of this vertical sintering machine A, particularly the blower device 4. In the figure, solid lines with arrows indicate an exhaust pipe and an air supply pipe, and broken lines indicate control signal lines. This blower device 4
In this case, the exhaust pipes 18, 18 connected to the suction ports 17.degree. 17 are each connected to a main exhaust pipe 21, and an exhaust fan 22 is connected to one end of the main exhaust pipe 21.

The discharge side of this exhaust fan 22 is connected to a chimney 23, and a dust collector 24 is provided on the inlet side. Further, a flow rate regulating valve 25 such as a butterfly valve is attached to the main exhaust pipe 21, and a rotary damper 26 is attached to the inlet side of this flow rate regulating valve 25, respectively. The flow rate adjustment valve 25 and the rotary damper 26 constitute an air flow rate adjustment mechanism 27 that adjusts the flow rate of exhaust gas discharged from the main exhaust pipe 21.

On the other hand, air for sintering is taken in through an air intake port 28 equipped with a silencer and a filter, and the main air supply pipe 29
The air supply pipes 19 and 19 branch from this and are led to the lower part of the sintering machine main body l. A flow rate sensor 30 is attached to this main air supply pipe 29, and a detection signal from this flow rate sensor 30 is sent to an opening calculation unit 31.
is sent to the flow rate controller 32 via the flow rate controller 32.
The output signal is sent to the flow rate regulating valve 25 via the bonnon yoner 33.

Furthermore, the flow rate controller 32 is connected to a programmer 34, and the flow rate controller 32 controls the valve opening degree of the flow rate adjustment valve 25 according to an air volume control program preset in the programmer 34. As a result, the amount of exhaust gas tN exhausted from the main exhaust pipe 20 is changed, and as a result, the volume of sintering air sucked through the main air supply pipe 29 is controlled. That is, the programmer 34 and the flow rate controller 32
7. This constitutes a control mechanism 35 for controlling 7.

Above, the configuration of this vertical sintering machine A, especially the blower device 4, has been described, but the other configurations are the same as those of the vertical sintering machine 16B described above, so the following explanation will be omitted.

Next, a sintering method using the vertical sintering machine A equipped with the above-described air blower 4 will be described with reference to FIG. 2.

First, the programmer 34 is programmed with a flow rate of exhaust gas per unit time to be discharged from the main exhaust pipe 21 (therefore,
A program is set to periodically change the amount of air sucked in (from 0) in a pattern as shown in FIG. This program changes the air flow rate to the maximum value V1 by periodically changing the opening degree of the flow rate regulating valve 25 at the period T.
and the minimum value ■2, and the average value V. is the critical wind ff when the raw material layer starts to form a fluid state
Make it slightly larger than 1V. In addition, the period T
It is desirable that the maximum time is about 20 to 30 seconds, and the minimum time is about 1 second.

After that, while exhausting and supplying air with the above ventilation pattern, proceed to the sintering machine as before! The raw material layer charged into the chamber is continuously sintered while descending.

As a result, productivity can be increased compared to the conventional case of m-travel air blowing. That is, when the air flow rate is larger than the critical air flow rate V, the raw material layer 6 exhibits a fluid state or a suspended state as shown in FIG. Combustion and melting are promoted and the sintering rate is sufficiently increased. Then, when the subsequent air flow rate becomes smaller than the critical air flow rate V, the raw material layer 6 is
The stable state shown in FIG. 1 is reached and the fluid state is eliminated, and if the sintered zone 8 is in a hanging state, the sintered zone 8 quickly descends and becomes the sintered zone 9 again. can be melted and solidified without degrading the quality of the finished product. According to this method, since the average airflow ffi vo is made larger than the limit airflow V in the case of conventional constant airflow, the average sintering speed is accelerated, and therefore productivity is increased. .

FIG. 3 shows a comparison between the production rate in the case of pulsating air blowing and the production rate in the case of conventional constant air volume blowing in a range where the pseudo particle diameter of the raw material is 5.0 to 6.0 nua. As is clear from FIG. 3, the average production rate P1 of each particle size is 1.5 t/m'h in the conventional constant air volume blowing, whereas the average production rate P1 in the pulsating air blowing of this embodiment is 1.5 t/m'h. , is 2, Ot
/ m”h, and the production rate can be improved by more than 30%.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various configurations are possible for, for example, the air flow rate adjustment mechanism and control mechanism.

"Effects of the Invention" As explained in detail above, according to the sintering method of the present invention, since the sintering air is supplied in a pulsating state,
By increasing the average wind speed of the sintering air, the sintering speed can be increased, thereby improving productivity.

Further, according to the vertical sintering machine of the present invention, since it is equipped with an airflow rate adjustment mechanism and a control mechanism that controls the airflow rate adjustment mechanism to bring the sintering air into a pulsating state, it is easy to adjust the sintering air. It can be brought into a pulsating state, and is effective in implementing the above method.

[Brief explanation of drawings]

1 to 3 are diagrams showing an embodiment of the present invention, FIG. 1 is a system diagram showing the ventilation system in the vertical sintering machine of this embodiment, FIG. 2 is a diagram showing the ventilation pattern, FIG. 3 is a diagram for explaining the effect of the sintering method using this vertical sintering machine. Figures 4 and 5 are diagrams showing a conventional vertical sintering machine, with Figure 4 being a side sectional view, and Figures 5 (a) to (c) showing the results when the air flow rate gradually increases. It is a partial side sectional view showing each state. A... Vertical sintering machine, l... Sintering machine main body, 2... Charging device, 3... Crushing device,
4... Air blower, 5... Sintering raw material, 6
. . . Raw material layer, 27 . . . Air flow rate adjustment mechanism, 35 . . . Control mechanism. Applicant Ishikawajima-Harima Heavy Industries Co., Ltd. Kawasaki Steel Corporation T 2T 3T (Time) Figure 4 Figure 5

Claims (2)

[Claims] (1) Powdered sintering raw material is charged into the vertical sintering machine from above to form a raw material layer, and while this raw material layer is moved downward, air for sintering is introduced into this raw material layer. In the sintering method, the sintered product is crushed and taken out from below the vertical sintering machine after sintering while supplying the raw material and discharging the exhaust gas generated during sintering. A sintering method characterized by supplying sintering air in a pulsating manner by periodically changing the amount of sintering air blown per unit time. (2) A sintering machine body that sinters a raw material layer made of powdered sintering raw material formed inside while moving downward, and a sintering machine that supplies sintering air to the raw material layer and sintering air. The sintering raw material is charged into the sintering machine body to form the raw material layer. In the vertical sintering machine equipped with a charging device for crushing the sintered product and a crushing device for crushing the sintered product, the blower device includes an air blowing rate adjustment mechanism that adjusts the blowing rate of the sintering air supplied to the raw material layer. 1. A vertical sintering machine comprising: a control mechanism for controlling the air flow rate adjusting mechanism to bring the sintering air into a pulsating state.