JPH08299735A - Dust removal material for dust removal moving bed - Google Patents

Abstract

PURPOSE: To provide a dust removal material for a moving bed by which dust is removed with high efficiency and stably from gas generated from a sintering furnace, a coke oven and a blast furnace. CONSTITUTION: A dust removal material consists of a porous granular material of 1-10mm particle diameter and 20-60% porosity such as coke and/or water- crushed granulated slag powder. Into a moving bed of this dust removal material, soot containing gas is introduced from a moving bed gas inlet 8, and it is passed through a packed bed 2 of the dust removal material to remove dust. The gas from which dust has been removed is discharged from a moving bed gas outlet 5. In this way, high concentration soot containing gas generated from a sintering furnace, a coke oven and a blast furnace is subjected to stable dust removal treatment by a simple means and with a high dust removal rate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust-removing material for removing dust contained in exhaust gas from a sintering furnace, a blast furnace, a coke oven or the like in the steel industry and non-ferrous metal refining industry with a moving bed.

[0002]

2. Description of the Related Art Gas generated from a sintering furnace, a blast furnace, and a coke oven contains a high concentration of soot and dust, and the exhaust gas from the sintering furnace and the coke oven is discharged after removing the soot or desulfurization or denitration. Processed and discharged into the atmosphere. In the case of blast furnace gas, it is used as a fuel gas after dust removal processing.

As equipment for removing dust from these gases,
Dust removal equipment such as electric dust collectors, bag filters, and venturi scrubbers are installed. Further, a dust removing equipment using a moving bed (for example, Japanese Patent Laid-Open No. 53-136769) is known, and sand, crushed limestone, etc. have been used as dust removing materials.

[0004]

The electrostatic precipitator and the bag filter dust removal equipment have a high dust removal rate and a small stable operation range due to the characteristics such as the temperature and humidity of exhaust gas, the particle size of soot dust and the apparent electrical resistivity. . Especially, it is extremely difficult to remove the alkaline fine particles in the dust with a high dust removal rate and in a stable operating condition.

Further, the Venturi scrubber used for dust removal of blast furnace gas is an excellent dust removal equipment capable of operating with high efficiency and stability, but since it has a large pressure loss and a large decrease in gas temperature, a blast furnace gas turbine is used. It is economically disadvantageous in a system having equipment for rotating and generating electricity.

Further, the conventional moving bed cannot be reused because a large amount of soot dust is attached to the packing moved and discharged in the packed bed. Therefore, it is necessary to completely remove the adhering powder before discarding or reusing. Of the soot and dust in the gas, which is the object of the present invention, fine particles are adhering, and therefore a facility for completely removing them is very expensive.

In view of the above problems, the present invention provides a dust removing material for a moving bed for dust removal, which is capable of removing dust generated from a sintering furnace, a coke oven and a blast furnace with high efficiency and stability.

[0008]

[Means for Solving the Problems]

(1) The present invention which solves the above-mentioned problems, in a dust remover of a moving layer for removing dust contained in a gas, wherein the dust remover has a particle size of 1 to 10 mm and a porosity of 20 to 60%. A dust removing material for a moving layer for dust removal, which is made of a substance.

(2) Further, in the above-mentioned dust removing material of the moving layer for dust removal, the porous particulate matter is coke and / or water granulation.

[0010]

In the above-mentioned means (1), the dust is removed by the packed bed by soot particles in the gas flowing in the space of the packed bed colliding with the packed particles and adhering to and carried on the surfaces of the packed particles. Removed from gas. The removal efficiency is determined by the following formula (1) of the packing.

[0011]

[Equation 1]

In the above formula (1), E is the dust removal rate, ε is the ratio of voids between the packing particles, that is, the porosity, L is the thickness (m) of the packing layer, and D is the packing particle diameter ( m) and η are dust collection efficiencies.

The dust collection efficiency largely depends on the shape of the packing, especially the surface area per unit volume. Therefore, the porous substance having a large surface area per unit volume can trap a large amount of dust as compared with the particles having a smooth surface.

The porous material referred to here is JIS, K2.
It is a substance having a high porosity measured by the method specified in 151-1977. According to this method, the total porosity is measured, but this value is generally in a proportional relationship with the open porosity, and generally represents the magnitude of the surface area per unit volume.

The reason why the porosity must be 20% or more is that the particles having a particle size of 1 mm or more have a porosity of 20 or more.
If it is less than%, the dust collection efficiency is low and the dust collection equipment becomes large, which is economically disadvantageous.

The reason why the porosity must be 60% or less is that, generally, an inexpensive raw material having a porosity of 60% or more has low strength and is pulverized in the moving bed. Mixed with the clean gas, the concentration of soot and dust in the outlet gas rises, the powder is pulverized in the moving bed, and the pressure loss increases due to the clogging of the moving bed, which is unsuitable as an industrial facility for treating a large amount of gas.

The reason why the particle size of the dust removing material to be filled in the moving bed must be 1 mm or more is that when powder having a particle size of less than 1 mm is mixed in the bed, the pressure loss when the gas passes through the moving bed is reduced. This is because the size becomes extremely large, which is unsuitable as an industrial facility for processing a large amount of gas, and the mixed powder is scattered by the gas flow, and the dust concentration of the outlet gas increases.

The particle size of the dust removing material packed in the moving bed is 10 mm.
The reason why it should be set to the following is that the dust removal capability is insufficient if it exceeds 10 mm.

Next, in the above-mentioned means (2), the reason why powdered coke and water granulation are selected as the porous substance is that these substances can be directly used as sintering raw materials after being subjected to dust removal. That is, it is excellent in that it does not require treatment equipment or a dumping place. For water granulation, powder coke has a higher porosity and is therefore a better dust remover.

Sintered ore particles are a similar porous material, but a sintered ore having a size of 3 mm or more can be used as a blast furnace raw material, and it is necessary to remove a large amount of dust adhering to it. is necessary. On the other hand, the occurrence rate of sinter having a size of 1 mm or more and 3 mm or less is small, and it is not sufficient as a filler for the moving layer.

[0021]

Embodiments of the present invention will be described below with reference to FIGS.

FIG. 2 is an explanatory diagram showing an example of the structure of the moving layer. The gas containing soot and dust is introduced from the moving bed gas inlet 8, passes through the packed bed 2, is dedusted, and is discharged to the moving bed gas outlet 5. On the other hand, the filler 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 material is controlled by controlling the operation of the cutting device 6. The cut filler is discharged from the valve 7 to the outside of the system. 3 is a louver and 4 is a wire mesh.

FIG. 1 shows an example in which dust removal characteristics were investigated by using sinter, powdered coke, granulated blast furnace, iron ore produced in Australia and sand as the filling material of the packed bed. The target gas is exhaust gas from a sintering machine having a sintering area of 500 m ² .
The layer thickness was 100 mm, and the particle size was adjusted to a particle size of 3 to 5 mm by sieving with a sieve having openings of 3 mm and 5 mm.

Sintered ore, powder coke with porosity shown in Table 1,
Blast-furnace granulation shows a higher dust removal rate than iron ore and sand, and the dust removal rate does not decrease even when a large amount of soot dust is introduced compared to iron ore and sand. The reason for exhibiting such excellent properties is that sinter, powdered coke, and granulated blast furnace are porous substances and have a large surface area per unit volume.

[0025]

[Table 1]

[0026]

As described above, the dust removing material of the present invention is
Composed of coke with a particle size of 1-10 mm and porosity of 20-60% and / or porous granular material such as water granulation, thus originating from sintering furnaces, coke ovens and blast furnaces containing high concentrations of soot and dust. A stable dust removal process can be performed on gas by a simple means and at a high dust removal rate.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of measuring the dust removal performance of a moving bed according to the present invention.

FIG. 2 is an explanatory diagram showing a configuration example of a moving layer of the present invention.

[Explanation of symbols]

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

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Teruo Aono 20-1 Shintomi, Futtsu City Nippon Steel Corporation Technical Development Division

Claims (2)

[Claims] 1. A dust remover for a moving bed for removing dust contained in a gas, wherein the dust remover is made of a porous granular material having a particle size of 1 to 10 mm and a porosity of 20 to 60%. Dust removal material for moving layer for dust removal. 2. The dust removing material for a moving layer for dust removal according to claim 1, wherein the porous granular material is coke and / or water granulation.