JPH06288686A - Operating method for moving layer - Google Patents

Abstract

PURPOSE:To efficiently and stably remove dusts of gas generated from a sintering furnace and a blast furnace by introducing exhaust gas of the sintering furnace or gas generated from the blast furnace, and passing it through a filling layer having sintering ore granulated into a special grain size range as filler to be discharged. CONSTITUTION:Gas containing smoke dust is introduced from a gas inlet 8, passed through a filling layer 2 to remove dusts, and discharged from a gas outlet 5. Louvers 3 are provided at an inlet side of the layer 2, and a metal gauze is provided at its outlet side. On the other hand, filler is charged from a valve 1 to the layer 2, and dropped through the layer from above downward. A dropping speed of the filler is controlled by controlling an operation of a filler cutter 6. The cut filler is discharged from a valve 7 out of a system. The filler is sintering ore granulated to a grain size range of 1 to 10mm. When powder having a grain size of less than 1mm is mixed, a pressure loss at the time of passing gas through the moving layer is increased. While when it is more than 10mm, a dust removing capacity is insufficient, and it is improper as a sintering raw material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving bed operation method most suitable for purifying gas discharged from sintering furnaces and blast furnaces in the steel and non-ferrous metal refining industries.

[0002]

2. Description of the Related Art Gas generated from a sintering furnace and a blast furnace contains a high concentration of soot and dust, and the exhaust gas from the sintering furnace is discharged after removing the soot or desulfurized or denitrated and discharged into the atmosphere. There is. In the case of blast furnace gas, it is used as a fuel gas after dust removal processing. As a facility for removing dust from these gases, dust collectors such as an electric dust collector, a bag filter, and a venturi scrubber are installed. In addition, a dust removing facility using a moving bed (for example, Japanese Patent Laid-Open No. 53-13676).
No. 9) is known.

[0003]

However, the electrostatic precipitator and the bag filter dedusting equipment have a high dedusting rate and a stable operation range depending on the characteristics such as temperature of exhaust gas, humidity, particle size of soot and apparent electric resistivity. Is small. In particular, it is extremely difficult to remove the alkaline fine particles in the dust with a high dust removal rate and a stable operating condition. In addition, the Venturi scrubber used for dust removal of blast furnace gas is an excellent dust removal facility that can be operated with high efficiency and stability,
Since the pressure loss is large and the gas temperature drop is large, it is economically disadvantageous in a system having equipment for rotating a turbine with blast furnace gas to generate electricity.

The conventional moving bed cannot be reused because a large amount of soot dust adheres to the packing moved and discharged in the packed bed. Therefore, it is necessary to completely remove the adhering powder before discarding or reusing. The particulate matter of the dust particles in the gas, which is the object of the present invention, has adhesiveness, and a facility for completely removing it requires a great deal of cost.

It is an object of the present invention to provide a method for operating a moving bed which is capable of stably removing dust generated from a sintering furnace and a blast furnace with high efficiency.

[0006]

The gist of the present invention is to introduce a sintering furnace exhaust gas or a blast furnace generated gas from an inlet to
A moving bed operation method is characterized in that a gas is passed through a packed bed in which a sinter ore sized in a particle size range of 10 mm or more and 10 mm or less is filled, and clean gas is discharged from an outlet.

[0007]

The operation and embodiment of the present invention will be described with reference to FIGS. 1 and 2.

[0008]

EXAMPLE FIG. 2 is an illustration of a moving layer. The gas containing soot and dust is introduced from the gas inlet 8, passes through the packed bed 2, is dedusted, and is discharged to the gas outlet 5. 3 is a louver and 4 is a wire mesh. On the other hand, the filling material is charged into the packed bed 2 from the valve 1 and descends from the upper side to the lower side in the packed bed. The descent rate of the filling is controlled by controlling the operation of the filling cutting device 6. The cut out filler is discharged from the valve 7 to the outside of the system.

FIG. 1 shows a sinter ore as a filling material for a packed bed,
This is an example of investigating dust removal characteristics using Australian iron ore and sand. The target gas is exhaust gas from a sintering machine having a sintering area of 500 m ² . Layer thickness is 100 mm, particle size is 3 mesh
mm and 5 mm sieves were used for sieving. Sintered ore is iron ore,
The dust removal rate is higher than that of sand, and the dust removal rate does not decrease even if a large amount of soot dust is introduced compared to iron ore and sand.
The reason for exhibiting such excellent properties is that sinter is a porous material and has a large surface area per unit deposition.

The dust removal by the packed bed is removed from the gas by the soot dust in the gas flowing in the space of the packed bed colliding with the packing particles and adhering to and carrying on the surfaces of the packing particles.
The efficiency of removal is determined by the number 1 of packings (I).

[0011]

[Equation 1] E: Dust removal ratio ε: Ratio of voids between packing particles, that is, void ratio L: Packing layer thickness (m) D: Packing particle diameter (m) η: Dust collection efficiency

The dust collection efficiency largely depends on the shape of the packing, especially the surface area per unit volume.

Table 1 shows the values of the open porosity and open porosity of the sintered ore used as a blast furnace raw material in the iron and steel industry, measured by the method disclosed in Japanese Patent Laid-Open No. 3-5480. According to the measurement, the open porosity of the sinter is 44% to 53%. That is, it is a porous material. The sintered ore used in the present invention is prepared by sizing and sieving the sintered ore, which is a porous material, and therefore has large irregularities except irregularities having a particle size of dust particles or less. Therefore, the surface area is much larger than that of particles having a smooth surface when viewed in a size larger than the dust particle size. That is, it means that η in the formula (I) is large, and a high dust removal rate can be obtained. The particle size of dust particles contained in the gas of the present invention is from 1 micron (μ) to 200 microns (μ)
99% or more is included in the range. In addition, it is possible to collect a large amount of soot dust because it is difficult for the soot dust collected from the gas to scatter due to the gas flow in the porous ore with a large unevenness with a radius of curvature of 1 micron (μ) or more Is.

[0014]

[Table 1]

The diameter of the particles of the sintered ore packed in the moving bed is 1
The reason why it must be more than mm is that if powder with a particle size of less than 1 mm is mixed in the bed, the pressure loss when the gas passes through the moving bed becomes extremely large, and as an industrial facility for processing a large amount of gas, This is because it is not suitable, and the mixed powder is scattered by the gas flow and the concentration of soot and dust in the outlet gas rises.

Another advantage of the sintered ore as a packing material for the moving bed for removing dust is that it can be used as it is as a sintering raw material after being subjected to dust removal. That is, it is excellent in that it does not require treatment equipment or a dumping place.

The diameter of the particles of the sintered ore packed in the moving bed is set to 1
The reason why it should be 0 mm or less is that if it exceeds 10 mm, the dust removal capability is insufficient, and if the sintering raw material exceeding 10 mm causes a decrease in yield, it is unsuitable as a sintering raw material. Although sinter having a diameter of more than 10 mm can be used as a blast furnace raw material, since a large amount of soot dust adheres to it, it is necessary to remove the adhering soot dust in order to use it as a blast furnace raw material. Removal equipment is required. Therefore, the advantage of using sinter is lost.

[0018]

According to the present invention, it is possible to perform a stable dust removal process with a high dust removal rate and a gas generated from a sintering furnace and a blast furnace containing a high concentration of soot dust.

[Brief description of drawings]

FIG. 1 is an example of the present invention, which is an example of measuring the dust removal performance of a moving bed.

FIG. 2 is an explanatory diagram of a moving layer.

[Explanation of symbols]

 1 Valve 2 Packed Bed 3 Louver 4 Wire Mesh 5 Gas Outlet 6 Packing Device 7 Valve 8 Gas Inlet

Front Page Continuation (72) Inventor Shiro Yoshitake 46-59 Nakahara, Tobata-ku, Kitakyushu, Fukuoka Prefecture Nippon Steel Corporation Machinery & Plant Division

Claims (1)

[Claims] 1. A sinter furnace exhaust gas or a blast furnace generated gas is introduced from an inlet to allow the gas to pass through a packed bed containing a sinter ore that has been sized to a particle size range of 1 mm or more and 10 mm or less, and from the outlet. A method of operating a moving bed, characterized by discharging clean gas.