JPH0121208B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a vertical sintering machine for producing lumpy sintered ore by baking and solidifying powdery ore. [Prior art] As a device for manufacturing sintered ore for blast furnaces by sintering powdered ore, such as powdered iron ore, a mixture of powdered ore, coke powder, and auxiliary raw materials is placed on an endless grate, and the mixture is horizontally The so-called Dwight Lloyd type sintering equipment, which sinters while moving, is common, but it has problems such as high firing energy, large amount of air leakage and waste gas, and difficulty in recovering the sensible heat of the finished product. To solve these problems, an exhaust gas circulation sintering method, an on-strand cooling method, etc. have been proposed, but there are problems such as a decrease in the quality of the sintered ore and a large amount of capital investment. For this reason, a vertical type sintering device that generally has high thermal efficiency has also been proposed. As a conventional rigid sintering furnace, for example, a device as shown in Fig. 7 has been proposed (Stahl u. Eisen 81 (1961) No. 7 S404~
407). This device is a vertical sintering machine equipped with a raw material supply hopper 1 and a ventilation zone raw material hopper 3 at the top, and an ignition device 15 and an air inlet 11 are provided in the middle part to form a sintered zone 5. The raw material hopper 3 is used as an exhaust gas suction port. This device has the following problems. Since it is an air blowing method, the sintering zone must be located in front of the blowing port, and since outside air (cold air) is used, the sensible heat of the product cannot be effectively used as combustion heat. The raw material layer 6 fluidizes and pops out due to the blowing pressure, making it impossible to form a stable raw material layer and causing environmental problems such as dust scattering. Furthermore, a new product cooling device or product sensible heat recovery device is required. Figure 8 is an example of another vertical sintering machine, but the present endless type sintering machine is simply rotated 90 degrees, except that the raw material is lowered by gravity, and it does not have the various problems mentioned above. Not resolved. In addition, various other ideas have been proposed, but all of them are merely possibilities; none have been technically developed, and none have been realized. [Problems to be Solved by the Invention] The present invention provides a vertical sintering machine with high thermal efficiency, and aims to solve the above-mentioned problems. In other words, the sensible heat of the product is utilized as a heat source for combustion, and the pressure of combustion air is not received by the raw material layer, but is received by the product layer, which prevents the raw material powder from fluidizing or flying out, and also allows the product to be cooled and combusted. The purpose of the present invention is to provide a device that completely recovers heat and also overcomes the problems faced by current endless sintering machines. According to the apparatus of the present invention, the sensible heat of the finished product, which could not be used in the past, can be used as a heat source for combustion, and the crushing of the finished product and heat exchange can be carried out in a series of processes, so the firing energy can be reduced. becomes. Further, in the conventional vertical furnace shown in FIG. 7, fluidization and scattering due to exhaust gas at the upper end of the raw material bed are unavoidable, but this can be prevented with the present invention. [Means for Solving the Problems] The structure of the present invention will be explained with reference to the drawings shown in FIGS. 1 to 6. FIG. 1 is an overall vertical sectional view of the vertical sintering machine. The vertical sintering machine of the present invention is applied to the process of producing bulk sintered ore by sintering powdered ore. The case of manufacturing ore will be explained as an example. As shown in FIG. 1, the vertical sintering machine of the present invention is equipped with a device for supplying sintering raw materials and aerated zone raw materials at the upper end, and below it is sequentially a raw material layer 6, a sintered zone 5, and a sintered completed layer. 7. Primary product cooling layer 7a, crushing chamber 14, 2
It is constructed by connecting the secondary product cooling layer 10 and the product discharge port 13, and air is introduced from near the lower end of the secondary product cooling layer 10, the ventilation zone 16, 1
The entire structure is such that the exhaust gas is sucked through the suction port 4 through the product cooling layer 7a and the sintering zone 5. The raw material supply device includes a device for supplying sintering raw materials and a device for supplying aeration zone raw materials. For example, as shown in a perspective view in FIG. 3, the device for supplying the sintering raw material includes a raw material supply hopper 1, a rotating cylindrical raw material supply drum feeder 2, and a cut gate 1a, and supplies a fixed amount of the sintering raw material to the raw material layer 6. . This sintering raw material is mixed with powdered iron ore, auxiliary raw materials, and a predetermined amount of coke powder in a pre-stage step (not shown), and the water content is adjusted to form pseudo particles, which are then supplied to the raw material layer 6. The aeration zone raw material supply device is a device for supplying aeration zone raw material for forming the aeration zone 16 at the center of the cross section of the sintered raw material layer, and for example, the aeration zone raw material supplying device as shown in a perspective view in FIG. Equipped with hopper 3. The aeration zone raw material corresponds to bedding ore in a Dwight Lloyd type sintering machine, and forms the aeration zone 16 for efficiently supplying the sintering air introduced from the bottom of the device of the present invention to the sintering zone 5. It is. The raw material for the vadose zone is
Particles having a coarser particle size than the sintering raw material, for example, particles generated in the process of sizing sintered products are used. The average particle size is desirably 1.5 to 5 times the average particle size of the sintered raw material in view of the relationship between the height of the ventilation zone and the sealing function described below. The aerated zone raw material supply hopper 3 extends its lower part downward to penetrate deeply into the raw material layer 6, and is formed so that its lower end determines the upper end position of the sintering zone 5, so that the sintered zone does not move further upwards. Position it so that it does not stretch. Moreover, this height is configured to have the height of the packed bed necessary to prevent air from entering from above through the aerated zone raw material in the hopper, and has a so-called raw material sealing function. Separate sealing devices can also be provided if necessary. FIG. 2 is an example, and the shape is not necessarily limited to this shape. Any device that can supply the aerated zone raw material to the center of the cross section of the sintered raw material layer 6 and regulate the position of the sintered zone can be used. Regardless of shape or structure. The raw material layer 6 is a packed bed filled with sintering raw materials supplied from above and moved downward by gravity.
This raw material layer 6 ensures a layer height so that air is not sucked through this raw material layer. A suction port is provided at the lower end of the raw material layer 6 to suck in exhaust gas in the horizontal and lateral directions. A sintered zone 5 is formed at approximately the same level as this suction port. The sintering zone 5 is a zone in which a predetermined amount of coke powder mixed in the sintering raw material is combusted by high-temperature air that has exchanged heat with the finished product, and the iron ore powder is sintered. A sintered completed layer 7 and a primary product cooling layer 7a are connected below the sintered zone. Sintered layers 7 and 1
The sintered ore sintered in the sintered layer 5 moves downward into the product cooling layer 7a, and rising air rises from below to exchange heat in a countercurrent manner. A crushing chamber 14 is provided below the primary product cooling layer 7a, and a crusher 8 is disposed therein. This crusher 8 is equipped with a hammer-shaped block on a shaft that reciprocates in the horizontal direction perpendicular to the moving direction of the primary product cooling layer 7a, that is, in the left-right direction (indicated by arrows) in FIG. The sintered ore descending from the product cooling layer 7a is roughly crushed by the impact force and compression force of the hammer block. The plane of the crushing chamber 14 is illustrated in FIG. In FIG. 4, three crushers 8 are arranged, and the direction of their reciprocating motion is indicated by an arrow. A secondary product cooling layer 10 is provided below the crushing chamber 14 . The secondary product cooling layer 10 is a packed bed of coarsely crushed finished sintered ore, and a cooling air introduction pipe 11 is attached to the lower end thereof. In the secondary product cooling layer 10, the high-temperature sintered ore is further cooled by the introduced cooling air, while the cooling air is heated and rises to be used as sintering air. Since this heat exchange is performed in a packed bed format, high heat exchange efficiency can be obtained. Therefore, the sensible heat possessed by the high-temperature sintered ore is effectively utilized in the sintering process. The secondary product cooling layer 10 has a product discharge port 1 at its lower end.
3, and the entire product cooling layer forms a product cooling hopper. A conveying device, such as a product belt conveyor 17, for transporting the product is disposed below the product discharge port 13. The belt conveyor 17 transports the product to a sizing device for the next step (not shown). The sintering device sizes the sintered ore to an appropriate particle size for charging the coarsely crushed product into the blast furnace. FIG. 5 shows the shape of a portion 4a of the suction port 4 which sucks the gas discharged from the sintering zone 5, which comes into contact with the sintering raw material. This suction port portion 4a has several horizontal slits stacked one on top of the other in consideration of dispersion of exhaust gas. FIG. 6 shows a cooling air inlet provided at the side of the lower end of the product cooling hopper 9. Swash plates are provided in several stages, and a slit-shaped air inlet is provided between each swash plate. Once the sintering machine of the present invention is ignited, the ignition progresses continuously using the ignition as a fire source, and theoretically no ignition device is required. , an ignition device 15 is installed for backup. The sintering operation of the sintering machine of the present invention is started as follows. At the start of the sintering operation, an inert substance, such as already sintered lump ore, is filled with air permeability from the lower end to the upper level of the igniter 15, and the raw material layer 6 above it is filled.
is filled with normal sintering raw materials mixed with coke powder. After that, while sucking air, the ignition device 15
ignition occurs, the crusher 8 is operated, the inert material layer is lowered at a predetermined speed, and normal sintering work begins. Once ignited by the igniter to form the combustion zone 5, the coke breeze in the falling sintering raw material is sequentially ignited, and normal sintering operations can be continued. At this stage, the ignition device 15 does not need to be operated. Further, if a combustion zone is partially missing or disappears for some reason during continuous operation, the ignition device can be operated to form a combustion zone. [Function] The sintering machine of the present invention has a vertical structure as a whole, and the sintering raw material is moved down in the furnace using gravity, and the combustion air is exchanged with the finished sintered ore from below in a countercurrent manner. Sensible heat is recovered and used for sintering. In addition, there are no sliding parts or moving parts, so there is no leakage loss, etc., and in conjunction with the above structure, thermal efficiency is extremely high, and low energy can be achieved without the need for ignition. [Example] Next, examples of the present invention will be given to explain the effects thereof. In the apparatus shown in FIG. 1, the air necessary for sintering is first heated in the product cooling hopper 9, and then
The exhaust gas is further preheated in the primary product cooling layer 7a, and after burning the coke powder in the raw material and forming the sintered zone 5, the exhaust gas is discharged from the suction port 4. As described above, in the apparatus of the present invention, the sensible heat of the finished product can be effectively utilized, so that the firing energy can be significantly reduced. Table 1 shows this in comparison with a conventional sintering machine.

[Table] As is clear from Table 1, the amount of sensible heat carried away as exhaust gas decreases as the amount of combustion air decreases. In addition, since the product sufficiently exchanges heat with air in the product cooling layer and product cooling hopper, the sensible heat taken out of the product is significantly reduced. Therefore, the amount of coke introduced into the sintering raw material can be reduced to about 2/3 of the conventional amount. Next, FIG. 9 illustrates the relationship between the passing air volume and suction pressure with respect to the raw material layer density in the conventional vertical sintering furnace without a ventilation zone and the vertical sintering furnace provided with the ventilation zone of the present invention. be. In the present invention, since the ventilation zone 16 is formed, the suction pressure is low and the amount of passing air can be increased, and the raw material layer can also descend smoothly, allowing stable operation. [Effects of the Invention] According to the apparatus of the present invention, the sensible heat of the product can be easily recovered and used directly for sintering, eliminating the need for continuous combustion in an ignition furnace, and significantly improving the thermal economy. Can be done. In addition, stable operation is possible without fluidization of the raw material layer unlike in conventional vertical furnaces.

[Brief explanation of drawings]

FIG. 1 is an overall sectional view of a vertical sintering machine showing the overall configuration of an embodiment of the present invention, FIGS. 2 to 6 are partial detailed views thereof, and FIG. FIG. 3 is a perspective view of the raw material supply hopper, FIG. 4 is a plan view of the product crushing device, FIG. 5 is a perspective view showing the shape of the suction port, and FIG. 6 is the shape of the cooling air port. The perspective view, FIGS. 7 and 8 are longitudinal sectional views of a conventional vertical sintering machine, and FIG. 9 is a graph showing a comparison between the conventional vertical sintering machine and the sintering machine of the present invention. 1... Raw material hopper, 2... Raw material supply drum feeder, 3... Ventilated zone raw material supply hopper, 4... Suction port, 5
... Sintered zone, 6... Sintered raw material layer, 7... Sintered completed layer, 7
a... Primary product cooling layer, 8... Crusher, 9... Product cooling hopper, 10... Secondary product cooling layer, 11... Cooling air pipe, 12... Air inlet, 13... Product discharge port, 1
4... Crushing chamber, 15... Ignition device, 16... Ventilation zone, 1
7... Finished product belt conveyor.

Claims (1)

[Claims] 1 Equipped with a device for supplying sintering raw material and aeration zone raw material at the upper end, and a raw material layer provided below,
The lower end portion of the aeration zone raw material hopper is inserted from the upper end into the center of the cross section of the raw material layer, extending downward, and a sintered zone is formed below the sintered zone. A primary product cooling layer, a crushing chamber, a secondary product cooling layer, and a product discharge port are sequentially installed in the vertical direction, and the above-mentioned 2
An air inlet is provided at the bottom end of the cooling layer for the next product, and an exhaust gas suction port is provided in the lateral direction of the sintering zone, and above the sintering zone, a layer of sintering raw material and ventilating material seals the suction air. A vertical sintering machine characterized by being given a height of