JP2001129338A - Dust collector of exhaust gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a dust collector of exhaust gas having a packed bed loaded with solid particles capable of keeping dust collecting efficiency high while reducing pressure loss as a filter medium. SOLUTION: A dust collector of an exhaust gas for removing dust from dust-containing high temperature exhaust gas by passing the exhaust gas through a filter medium is equipped with a particle packed furnace connected to the discharge part of an exhaust gas duct through which dust-containing high temperature exhaust gas flows at the lower side part thereof and having a discharge port at the upper part thereof, the particle packed bed 3 loaded with solid particles 10 as a filter medium formed in the particle packed furnace and the air permeable partition plate 5 arranged in the particle packed furnace in contact with the upper surface of the particle packed bed 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for removing dust contained in high-temperature corrosive exhaust gas discharged from a blast furnace, a direct reduction furnace, a smelting reduction furnace, a sintering furnace, an electric furnace, an incinerator, a combustion furnace, and the like. More particularly, the present invention relates to a dust collecting apparatus loaded with solid particles as a filtration medium.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional coal gasifier including a high-temperature exhaust gas dust collector filled with solid particles as a filtration medium disclosed in Japanese Patent Application Laid-Open No. 9-202887. FIG. In the figure, a shaft furnace 107 as a packed bed is connected to a spouted bed gasifier
06 is a dust collector with a counter-current moving packed bed filled with coke 110 for collecting scattered slag and unburned char contained in the high-temperature exhaust gas discharged through the filter medium. A certain coke replenishing device 111
A discharge device 112 for discharging scattered slag and unburned char collected together with the coke and coke is attached.

[0003]

In a conventional dust collector for high-temperature exhaust gas filled with solid particles as a filtration medium,
In order to maintain a high dust collection efficiency, it is conceivable to increase the gas superficial velocity, but if the gas superficial velocity is increased, the phenomenon of fluidization of the filter particles forming the packed bed occurs and adversely affects dust collection. However, since the dust collection efficiency decreases, the upper limit of the gas superficial velocity is restricted, and there is a problem that it is difficult to achieve good dust collection efficiency. In addition, it is conceivable to increase the diameter of the packed bed in order to increase the dust collection efficiency, but this causes a problem that it is not economical.

[0004] The inventors of the present invention have conducted intensive studies on the dust collecting function of a high-temperature exhaust gas dust collecting apparatus loaded with solid particles as a filtration medium in a packed bed. As a result, inertial collisions govern the dust collecting mechanism in the packed bed. Is considered relevant. Therefore, as the gas flow rate increases, the dust particles tend to separate from the airflow due to the inertial force,
The chance of contact with the filtration media increases, which increases the dust collection efficiency.However, as the gas flow rate increases, the kinetic energy of the dust particles also increases as the gas flow rate increases. The particles will rebound, and the kinetic energy of the air current will frequently cause the dust that has already adhered to re-scatter,
As a result, the dust collection efficiency decreases, and as a result, the dust collection efficiency takes the maximum value of the flow velocity that balances the effects of both inertial collision and re-dispersion.
It is necessary to set the fluidization start speed at the maximum.

The present invention has been made based on the above-mentioned research results, and an object of the present invention is to provide an exhaust gas dust collecting apparatus in which a solid particle capable of maintaining high dust collecting efficiency with a small pressure loss is loaded into a packed bed as a filtration medium. And

[0006]

According to a first aspect of the present invention, there is provided an exhaust gas dust collecting apparatus for removing high-temperature exhaust gas containing dust by passing the same through a filtration medium. A particle filling furnace having a lower side connected to the discharge side of an exhaust gas duct through which high-temperature exhaust gas flows, and having an outlet above, and particles formed by loading solid particles as a filtration medium into the particle filling furnace It is provided with a packed bed and a partition plate disposed in the particle packed furnace and capable of ventilating and contacting the upper surface of the particle packed bed.

The exhaust gas dust collecting apparatus according to a second aspect of the present invention is an exhaust gas dust collecting apparatus for removing high temperature exhaust gas containing dust by passing the same through a filtration medium. A particle filling furnace having a lower side connected to the discharge side of the flowing exhaust gas duct, having a discharge port on the upper side, and having a smaller diameter at the lower gas inlet portion and a larger diameter at the upper gas outlet portion; And a particle-packed layer in which the diameter on the lower gas inlet side is small and the diameter on the upper gas outlet side is large.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a schematic sectional view showing an exhaust gas dust collecting apparatus according to Embodiment 1 of the present invention, and FIG.
Is a graph showing a state in which the dust collection efficiency changes with respect to the gas superficial velocity of the bed packed with the filtered particles. In the figure, reference numeral 1 denotes an exhaust gas duct through which high-temperature exhaust gas including dust flows, and 2 denotes a particle-filling furnace having a lower side connected to the exhaust side of the exhaust gas duct 1 and having a tapered bottom portion. 10 (hereinafter, solid particles as filtration media
0). Reference numeral 3 denotes a particle packed bed of the filtered particles 10 formed in the particle packed furnace 2. here,
The particle-packed layer 3 is formed of the filtered particles 10 in the particle-filling furnace 2 and located between the lower gas inlet side and the upper gas-outlet side in the particle packed furnace 2. . Reference numeral 4 denotes a clean gas duct connected to the upper side of the particle filling furnace 2. Reference numeral 5 denotes a partition plate disposed above the inside of the particle filling furnace 2 for preventing fluidization of the air-permeable filter particles 10, which is constituted by a perforated plate, and has a hole diameter smaller than that of the filter particles. 6 is a particle supply pipe provided through the top wall of the particle filling furnace 2 and the partition plate 5 to supply filtered particles 10;
Is a particle cutting device provided at the bottom of the particle filling furnace 2 for discharging the filtered particles 10 to the outside.

Next, the operation of the exhaust gas dust collecting apparatus according to Embodiment 1 of the present invention will be described. The high-temperature dust-containing exhaust gas flowing in the exhaust gas duct 1 is filled in the particle packed bed 3 of the particle packed furnace 2.
And is discharged from the upper part through the particle packed bed 3. When the dust-containing exhaust gas passes through the particle-packed layer 3, the dust is adsorbed by the filter particles 10 to become a clean gas from which dust has been removed, and is discharged to the clean duct 5. Further, a fixed amount of the filtered particles 10 in which the dust is accumulated in the particle packed bed 3 of the particle packed furnace 2 is extracted by a particle extracting device 7.
At the same time, new filtration particles 10 are supplied to the upper part of the particle packed bed 3 from the particle supply pipe 6, so that the pressure loss is suppressed to a predetermined value or less.

In the first embodiment of the present invention, the partition plate 5 which is provided in the particle-filling furnace 2 and which can contact with the upper surface of the particle-packed layer 3 is provided in the particle-filled furnace 2. When the gas superficial velocity in 3 is increased to the fluidization start velocity or more, the filtration velocity exceeds the fluidization start velocity of the filtration particles 10 and the filtration particles 10 in the upper part of the particle packed bed 3 are fluidized.
This is because the partition plate 5 prevents fluidization of the filtered particles 10, so that the gas superficial velocity can be increased to be higher than the fluidization start velocity, and high dust collection efficiency can be secured.

Embodiment 1 As Embodiment 1 of the present invention, a case where the exhaust gas dust collecting apparatus of Embodiment 1 is used will be described. In Example 1, Table 1 shows the conditions of the high-temperature exhaust gas, and Table 2 shows the pressure loss and dust collection efficiency of the dust collector. The operating conditions of the dust collector were as follows: filter particles used: ceramic balls, particle size: 1 mm (minimum fluidization speed: 0.35 m / s, superficial velocity at maximum dust collection efficiency: 1)
m / s), density: 2000 kg / m 3, and particle cutting speed: 2500 kg / h.

On the other hand, it is obtained from another test result that under these conditions, the gas superficial velocity at which the maximum dust collection efficiency in the particle-packed layer 3 is 1.0 m / s. For this reason, the apparatus diameter of the particle packed bed 3 was determined so that the gas superficial velocity became 1.0 m / s. When the gas superficial velocity is increased to 1.0 m / s, since the fluidization start speed of the filtration particles is exceeded, the filtration particles are fluidized and the dust collection efficiency is reduced. Since the fluidization of the filtration particles 10 can be prevented by installing the partition plate 5 at the upper part, the gas superficial velocity can be increased to be higher than the fluidization start velocity as shown in FIG. Can be secured. This means that, as shown in Table 2, the dust collecting apparatus for high temperature exhaust gas of the present invention can increase the dust collecting efficiency by increasing the gas superficial velocity, and greatly reduce the pressure loss as compared with the conventional example. You can see that there is.

[0013]

[Table 1]

[0014]

[Table 2]

Embodiment 2 FIG. 3 is a schematic sectional view showing an exhaust gas dust collecting apparatus according to Embodiment 2 of the present invention. In the drawing, in the second embodiment of the present invention, the same components as those in the first embodiment are denoted by the same reference numerals, and the description of the same components will be omitted. In the second embodiment, the particle filling furnace 2 has a special shape instead of the partition plate 5 provided in the particle filling furnace 2 of the first embodiment. That is, in the second embodiment,
The side wall of the particle packed furnace 2 is inclined such that the diameter gradually increases from the lower gas inlet to the upper gas outlet, so that the diameter of the lower gas inlet side of the filtration particle packed bed 3 is smaller and the upper diameter is smaller. The diameter on the gas outlet side is increased.

As described above, the side wall of the particle-packing furnace 2 is inclined so that its diameter gradually increases from the lower gas inlet to the upper gas outlet, and the lower side of the particle-packed layer 3 is formed on the gas inlet side. The reason for reducing the diameter and increasing the diameter on the upper gas outlet side is that even if the gas superficial velocity in the particle packed bed 3 of the particle packed furnace 2 is increased to the fluidization start speed or more on the inlet side, the particle packed bed 3 There is no danger that the particles will be fluidized due to the lower part of the filter.
Since the fluidization start speed does not exceed the fluidization start speed, the gas superficial velocity can be imaged higher than the fluidization start speed in order to prevent the fluidization of the filtration particles 10, and high dust collection efficiency can be secured.

Embodiment 2 As Embodiment 2 of the present invention, a case where the exhaust gas dust collecting apparatus of Embodiment 2 is used will be described. In Example 2, Table 3 shows conditions of high-temperature exhaust gas, and Table 4 shows pressure loss and dust collection efficiency of the dust collector. The operating conditions of the dust collector were as follows: filter particles used: ceramic balls, particle size: 1 mm (fluidization start speed: 0.35 m / s), density: 2000 kg / m 3,
Particle cutting speed: 2500 kg / h. On the other hand, it is obtained from another test result that under this condition, the gas superficial velocity at which the maximum dust collection efficiency in the particle packed bed 3 is 1.0 m / s. Then, the gas flow rate set at the inlet of the particle-packed layer 3 is 1.0 m / s, and the gas flow rate set at the outlet of the particle-packed layer 3 is 0.3 m / s. 1.0 m, and the outlet diameter: 2.0 m.

Since dust mainly adheres to the filtered particles 10 at the dust-containing gas inlet side of the particle-packed bed 3 of the particle-packed furnace 2, the dust is collected in this region compared to the outlet side downstream of the particle-packed bed 3. The percentage increases. Therefore, in order to obtain high dust collection efficiency, the inlet diameter of the gas-filled layer 3 is determined so that the gas flow velocity at the gas inlet of the particle-filled layer 3 is 1.0 m / s. In this case, although the gas flow velocity is higher than the fluidization start velocity, there is no danger of the particles being fluidized due to the lower part of the gas-filled layer 3. On the other hand, dust is smaller on the gas outlet side of the gas-filled layer 3 than on the inlet side, but adheres to the filter particles 10 and determines the final dust collection efficiency. However, when the diameter of the gas-filled layer 3 on the gas outlet side is set to be the same as the diameter of the gas-filled layer 3 on the gas inlet side, the speed of the fluidized particle 10 exceeds the fluidization start speed. Dust re-scatters and the dust collection efficiency decreases. Therefore, the gas flow velocity at the outlet side is equal to or less than the fluidization start velocity (0.35 m / s or less)
The diameter on the outlet side of the gas-filled layer 3 is determined so that

In order to make the inlet and outlet sides of the gas packed bed 3 have different diameters, a method of making the side wall of the tower particle packed furnace 2 inclined as shown in FIG. 3 or a method of setting the diameter in two stages. There is. Thus, even if the gas superficial velocity in the particle packed bed 3 of the particle packed bed 2 is increased to 1.0 m / s on the inlet side, there is no possibility that the particles are fluidized due to the lower part of the particle packed bed 3. Since the diameter on the inlet side and the diameter on the outlet side of the filtration particle packed bed 3 are reduced, the fluidization start speed of the filtration particles 10 at the gas flow rate of 0.35 m / s or less on the exit side of the particle packed bed 3 is reduced. This is because the flow rate does not exceed the value, and in order to prevent fluidization of the filtration particles 10, the gas superficial velocity can be increased to be higher than the fluidization start velocity, and high dust collection efficiency can be secured. This means that, in Table 4, the dust collecting apparatus for high temperature exhaust gas of the present invention can increase the dust collecting efficiency by increasing the gas superficial velocity, and greatly reduce the pressure loss, as compared with the conventional example. You can see that there is.

[0020]

[Table 3]

[0021]

[Table 4]

In the first and second embodiments, specific numerical values have been described as dust collectors for high-temperature exhaust gas. However, the diameter and shape of the particle packed layer 3 and the particle size and shape of the filtration particles 10 are as follows. The present invention is not limited to this, and an optimal apparatus can be selected based on the gas amount of the high-temperature exhaust gas, the temperature, the dust content, the particle size distribution of the dust, the target dust collection efficiency, and the like. In the above description, the description regarding the filtration particles 10 is omitted, but specifically, ceramic balls, alumina balls,
Iron ore, coal, activated carbon, coke, silica sand, gravel, cement clinker, etc. can be used, and the particle size is 0.5 to 50 mm.
Some are used. In addition, the filter particles 10 in which the dust is accumulated and discharged may be used by removing the dust by means such as sieving or washing with water, or may be reused together with the dust, for example, when coke is used as the filter particle particles for another use. May be used as fuel for electric furnaces. Further, regarding the discharge and supply of the filtration particles, in the above description, the supply is performed after the filtration particles are discharged. However, it is needless to say that the filtration particles may be supplied while being discharged.

[0023]

As described above, according to the first aspect of the present invention, there is provided an exhaust gas collecting apparatus for removing high-temperature exhaust gas containing dust by passing the same through a filtration medium. The lower side is connected to the discharge side of the exhaust gas duct through which the gas flows, and solid particles as a filtration medium are loaded into a particle-filling furnace having a discharge port on the upper side to form a particle-packed layer, and high-temperature exhaust gas contacts the upper surface. Since dust is removed from exhaust gas by passing through a particle packed bed provided with a ventilable partition plate, the gas superficial velocity in the particle packed bed is increased to a predetermined value or more, and fluidization of the filtered particles is started. Even if the filtration particles at the top of the particle packed bed are fluidized beyond the speed, the partition plate prevents the fluidization of the filtration particles, so that the gas superficial velocity can be increased to ensure high dust collection efficiency, and the pressure loss is reduced. Significantly lower There is an effect of.

According to a second aspect of the present invention, there is provided an exhaust gas collecting apparatus for removing high-temperature exhaust gas containing dust by passing the same through a filtration medium, wherein the exhaust gas duct through which high-temperature exhaust gas containing dust flows. The lower side portion is connected to the discharge side, has a discharge port on the upper side, the diameter of the lower gas inlet portion is small, and the diameter of the upper gas outlet portion is large. A particle-packed layer is formed by loading, and high-temperature exhaust gas is passed through a particle-packed layer having a small diameter on the lower gas inlet side and a large diameter on the upper gas outlet side to remove dust from the exhaust gas. So
Even if the gas superficial velocity in the particle packed bed is increased to the fluidization start speed on the gas inlet side, the gas inlet side of the particle packed bed is at the lower part, so there is no risk of particles being fluidized, and the gas outlet of the particle packed bed On the side, the gas flow rate is equal to or less than the fluidization start speed, and does not exceed the fluidization start speed of the filtered particles, so that the fluidization of the filtered particles can be prevented, so that the gas superficial velocity can be increased to secure high dust collection efficiency, Moreover, there is an effect that the pressure loss is significantly reduced.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an exhaust gas dust collecting apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a graph showing a state in which the dust collection efficiency changes with respect to the gas superficial velocity of the particle packed bed.

FIG. 3 is a schematic sectional view of an exhaust gas dust collecting apparatus according to Embodiment 2 of the present invention.

FIG. 4 is an explanatory diagram showing a conventional coal gasifier including a flue gas dust collector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Exhaust gas duct 2 Particle filling furnace 3 Particle filling layer 5 Partition plate 10 Fixed particles

[Procedure amendment]

[Submission date] November 15, 1999 (1999.11.
15)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Exhaust gas dust collector

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for removing dust contained in high-temperature corrosive exhaust gas discharged from a blast furnace, a direct reduction furnace, a smelting reduction furnace, a sintering furnace, an electric furnace, an incinerator, a combustion furnace, and the like. More particularly, the present invention relates to a dust collecting apparatus loaded with solid particles as a filtration medium.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional coal gasifier including a high-temperature exhaust gas dust collector filled with solid particles as a filtration medium disclosed in Japanese Patent Application Laid-Open No. 9-202887. FIG. In the figure, a shaft furnace 107 as a packed bed is connected to a spouted bed gasifier
06 is a dust collector with a countercurrent moving packed bed filled with coke 110 for collecting scattered slag and unburned char contained in the high-temperature exhaust gas discharged through the filter medium. A certain coke replenishing device 111
A discharge device 112 for discharging scattered slag and unburned char collected together with the coke and coke is attached.

[0003]

In a conventional dust collector for high-temperature exhaust gas filled with solid particles as a filtration medium,
In order to maintain a high dust collection efficiency, it is conceivable to increase the gas superficial velocity, but if the gas superficial velocity is increased, the phenomenon of fluidization of the filter particles forming the packed bed occurs and adversely affects dust collection. However, since the dust collection efficiency decreases, the upper limit of the gas superficial velocity is restricted, and there is a problem that it is difficult to achieve good dust collection efficiency. In addition, it is conceivable to increase the diameter of the packed bed in order to increase the dust collection efficiency, but this causes a problem that it is not economical.

[0004] The inventors of the present invention have conducted intensive studies on the dust collecting function of a high-temperature exhaust gas dust collecting apparatus loaded with solid particles as a filtration medium in a packed bed. As a result, inertial collisions govern the dust collecting mechanism in the packed bed. Is considered relevant. Therefore, as the gas flow rate increases,
Dust particles tend to separate from the airflow due to their inertial force, increasing the chances of contact with the filtration medium and increasing dust collection efficiency.However, as the gas flow rate increases, the kinetic energy of the dust particles also increases Since it increases as the flow velocity increases, the dust particles rebound on the medium surface, and the kinetic energy of the air current frequently causes re-dispersion of the dust already attached,
As a result, the dust collection efficiency decreases, and as a result, the dust collection efficiency takes the maximum value of the flow velocity that balances the effects of both inertial collision and re-dispersion.
It is necessary to set the fluidization start speed at the maximum.

The present invention has been made based on the above-mentioned research results, and an object of the present invention is to provide an exhaust gas dust collecting apparatus in which a solid particle capable of maintaining high dust collecting efficiency with a small pressure loss is loaded into a packed bed as a filtration medium. And

[0006]

According to a first aspect of the present invention, there is provided an exhaust gas dust collecting apparatus for removing high-temperature exhaust gas containing dust by passing the same through a filtration medium. A particle filling furnace having a lower side connected to the discharge side of an exhaust gas duct through which high-temperature exhaust gas flows, and having an outlet above, and particles formed by loading solid particles as a filtration medium into the particle filling furnace It is provided with a packed bed and a partition plate disposed in the particle packed furnace and capable of ventilating and contacting the upper surface of the particle packed bed.

The exhaust gas dust collecting apparatus according to a second aspect of the present invention is an exhaust gas dust collecting apparatus for removing high temperature exhaust gas containing dust by passing the same through a filtration medium. A particle filling furnace having a lower side connected to the discharge side of the flowing exhaust gas duct, having a discharge port on the upper side, and having a smaller diameter at the lower gas inlet portion and a larger diameter at the upper gas outlet portion; And a particle-packed layer in which the diameter on the lower gas inlet side is small and the diameter on the upper gas outlet side is large.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a schematic sectional view showing an exhaust gas dust collecting apparatus according to Embodiment 1 of the present invention, and FIG.
Is a graph showing a state in which the dust collection efficiency changes with respect to the gas superficial velocity of the bed packed with the filtered particles. In the figure, reference numeral 1 denotes an exhaust gas duct through which high-temperature exhaust gas including dust flows, and 2 denotes a particle-filling furnace having a lower side connected to the exhaust side of the exhaust gas duct 1 and having a tapered bottom portion. 10 (hereinafter, solid particles as filtration media
0). Reference numeral 3 denotes a particle packed bed of the filtered particles 10 formed in the particle packed furnace 2. here,
The particle-packed layer 3 refers to a particle formed of the filtered particles 10 in the particle-filling furnace 2 that is between the lower gas inlet side and the upper gas-outlet side in the particle packed furnace 2. . Reference numeral 4 denotes a clean gas duct connected to the upper side of the particle filling furnace 2. Reference numeral 5 denotes a partition plate disposed above the inside of the particle filling furnace 2 for preventing fluidization of the air-permeable filter particles 10, which is constituted by a perforated plate, and has a hole diameter smaller than the filter particle diameter. 6 is a particle supply pipe provided through the top wall of the particle filling furnace 2 and the partition plate 5 to supply filtered particles 10;
Is a particle cutting device provided at the bottom of the particle filling furnace 2 for discharging the filtered particles 10 to the outside.

Next, the operation of the exhaust gas dust collecting apparatus according to Embodiment 1 of the present invention will be described. The high-temperature dust-containing exhaust gas flowing in the exhaust gas duct 1 is filled in the particle packed bed 3 of the particle packed furnace 2.
And is discharged from the upper part through the particle packed bed 3. When the dust-containing exhaust gas passes through the particle-packed layer 3, the dust is adsorbed by the filter particles 10 to become a clean gas from which dust has been removed, and is discharged to the clean duct 5. Further, a fixed amount of the filtered particles 10 in which the dust is accumulated in the particle packed bed 3 of the particle packed furnace 2 is extracted by a particle extracting device 7.
At the same time, new filtration particles 10 are supplied to the upper part of the particle packed bed 3 from the particle supply pipe 6, so that the pressure loss is suppressed to a predetermined value or less.

In the first embodiment of the present invention, the partition plate 5 which is provided in the particle-filling furnace 2 and which can contact with the upper surface of the particle-packed layer 3 is provided in the particle-filled furnace 2. When the gas superficial velocity in 3 is increased to the fluidization start velocity or more, the filtration velocity exceeds the fluidization start velocity of the filtration particles 10 and the filtration particles 10 in the upper part of the particle packed bed 3 are fluidized.
This is because the partition plate 5 prevents fluidization of the filtered particles 10, so that the gas superficial velocity can be increased to be higher than the fluidization start velocity, and high dust collection efficiency can be secured.

Embodiment 1 As Embodiment 1 of the present invention, a case where the exhaust gas dust collecting apparatus of Embodiment 1 is used will be described. In Example 1, Table 1 shows the conditions of the high-temperature exhaust gas, and Table 2 shows the pressure loss and dust collection efficiency of the dust collector. The operating conditions of the dust collector were as follows: filter particles used: ceramic balls, particle size: 1 mm (minimum fluidization speed: 0.35 m / s, superficial velocity at maximum dust collection efficiency: 1)
m / s), density: 2000 kg / m 3, and particle cutting speed: 2500 kg / h.

On the other hand, it is obtained from another test result that under these conditions, the gas superficial velocity at which the maximum dust collection efficiency in the particle-packed layer 3 is 1.0 m / s. For this reason, the apparatus diameter of the particle packed bed 3 was determined so that the gas superficial velocity became 1.0 m / s. When the gas superficial velocity is increased to 1.0 m / s, since the fluidization start speed of the filtration particles is exceeded, the filtration particles are fluidized and the dust collection efficiency is reduced. Since the fluidization of the filtration particles 10 can be prevented by installing the partition plate 5 at the upper part, the gas superficial velocity can be increased to be higher than the fluidization start velocity as shown in FIG. Can be secured. This means that, as shown in Table 2, the dust collecting apparatus for high temperature exhaust gas of the present invention can increase the dust collecting efficiency by increasing the gas superficial velocity, and greatly reduce the pressure loss as compared with the conventional example. You can see that there is.

[0013]

[Table 1]

[0014]

[Table 2]

Embodiment 2 FIG. 3 is a schematic sectional view showing an exhaust gas dust collecting apparatus according to Embodiment 2 of the present invention. In the drawing, in the second embodiment of the present invention, the same components as those in the first embodiment are denoted by the same reference numerals, and the description of the same components will be omitted. In the second embodiment, the particle filling furnace 2 has a special shape instead of the partition plate 5 provided in the particle filling furnace 2 of the first embodiment. That is, in the second embodiment,
The side wall of the particle packed furnace 2 is inclined such that the diameter gradually increases from the lower gas inlet to the upper gas outlet, so that the diameter of the lower gas inlet side of the filtration particle packed bed 3 is smaller and the upper diameter is smaller. The diameter on the gas outlet side is increased.

As described above, the side wall of the particle-packing furnace 2 is inclined so that its diameter gradually increases from the lower gas inlet to the upper gas outlet, and the lower side of the particle-packed layer 3 is formed on the gas inlet side. The reason for reducing the diameter and increasing the diameter on the upper gas outlet side is that even if the gas superficial velocity in the particle packed bed 3 of the particle packed furnace 2 is increased to the fluidization start speed or more on the inlet side, the particle packed bed 3 There is no danger that the particles will be fluidized due to the lower part of the filter.
Since the fluidization start speed does not exceed the fluidization start speed, the gas superficial velocity can be imaged higher than the fluidization start speed in order to prevent the fluidization of the filtration particles 10, and high dust collection efficiency can be secured.

Embodiment 2 As Embodiment 2 of the present invention, a case where the exhaust gas dust collecting apparatus of Embodiment 2 is used will be described. In Example 2, Table 3 shows conditions of high-temperature exhaust gas, and Table 4 shows pressure loss and dust collection efficiency of the dust collector. The operating conditions of the dust collector were as follows: filter particles used: ceramic balls, particle size: 1 mm (fluidization start speed: 0.35 m / s), density: 2000 kg / m 3,
Particle cutting speed: 2500 kg / h. On the other hand, it is obtained from another test result that under this condition, the gas superficial velocity at which the maximum dust collection efficiency in the particle packed bed 3 is 1.0 m / s. Then, the gas flow rate set at the inlet of the particle-packed layer 3 is 1.0 m / s, and the gas flow rate set at the outlet of the particle-packed layer 3 is 0.3 m / s. 1.0 m, and the outlet diameter: 2.0 m.

Since dust mainly adheres to the filtered particles 10 at the dust-containing gas inlet side of the particle-packed bed 3 of the particle-packed furnace 2, the dust is collected in this region compared to the outlet side downstream of the particle-packed bed 3. The percentage increases. Therefore, in order to obtain high dust collection efficiency, the inlet diameter of the gas-filled layer 3 is determined so that the gas flow velocity at the gas inlet of the particle-filled layer 3 is 1.0 m / s. In this case, although the gas flow velocity is higher than the fluidization start velocity, there is no danger of the particles being fluidized due to the lower part of the gas-filled layer 3. On the other hand, dust is smaller on the gas outlet side of the gas-filled layer 3 than on the inlet side, but adheres to the filter particles 10 and determines the final dust collection efficiency. However, when the diameter of the gas-filled layer 3 on the gas outlet side is set to be the same as the diameter of the gas-filled layer 3 on the gas inlet side, the speed of the fluidized particle 10 exceeds the fluidization start speed. Dust re-scatters and the dust collection efficiency decreases. Therefore, the gas flow velocity at the outlet side is equal to or less than the fluidization start velocity (0.35 m / s or less)
The diameter on the outlet side of the gas-filled layer 3 is determined so that

In order to make the inlet and outlet sides of the gas packed bed 3 have different diameters, a method of making the side wall of the tower particle packed furnace 2 inclined as shown in FIG. 3 or a method of setting the diameter in two stages. There is. Thus, even if the gas superficial velocity in the particle packed bed 3 of the particle packed bed 2 is increased to 1.0 m / s on the inlet side, there is no possibility that the particles are fluidized due to the lower part of the particle packed bed 3. Since the diameter on the inlet side and the diameter on the outlet side of the filtration particle packed bed 3 are reduced, the fluidization start speed of the filtration particles 10 at the gas flow rate of 0.35 m / s or less on the exit side of the particle packed bed 3 is reduced. This is because the flow rate does not exceed the value, and in order to prevent fluidization of the filtration particles 10, the gas superficial velocity can be increased to be higher than the fluidization start velocity, and high dust collection efficiency can be secured. This means that, in Table 4, the dust collecting apparatus for high temperature exhaust gas of the present invention can increase the dust collecting efficiency by increasing the gas superficial velocity, and greatly reduce the pressure loss, as compared with the conventional example. You can see that there is.

[0020]

[Table 3]

[0021]

[Table 4]

In the first and second embodiments, specific numerical values have been described as dust collectors for high-temperature exhaust gas. However, the diameter and shape of the particle packed layer 3 and the particle size and shape of the filtration particles 10 are as follows. The present invention is not limited to this, and an optimal apparatus can be selected based on the gas amount of the high-temperature exhaust gas, the temperature, the dust content, the particle size distribution of the dust, the target dust collection efficiency, and the like. In the above description, the description regarding the filtration particles 10 is omitted, but specifically, ceramic balls, alumina balls,
Iron ore, coal, activated carbon, coke, silica sand, gravel, cement clinker, etc. can be used, and the particle size is 0.5 to 50 mm.
Some are used. In addition, the filter particles 10 in which the dust is accumulated and discharged may be used by removing the dust by means such as sieving or washing with water, or may be reused together with the dust, for example, when coke is used as the filter particle particles for another use. May be used as fuel for electric furnaces. Further, regarding the discharge and supply of the filtration particles, in the above description, the supply is performed after the filtration particles are discharged. However, it is needless to say that the filtration particles may be supplied while being discharged.

[0023]

As described above, according to the first aspect of the present invention, there is provided an exhaust gas collecting apparatus for removing high-temperature exhaust gas containing dust by passing the same through a filtration medium. The lower side is connected to the discharge side of the exhaust gas duct through which the gas flows, and solid particles as a filtration medium are loaded into a particle-filling furnace having a discharge port on the upper side to form a particle-packed layer, and high-temperature exhaust gas contacts the upper surface. Since dust is removed from exhaust gas by passing through a particle packed bed provided with a ventilable partition plate, the gas superficial velocity in the particle packed bed is increased to a predetermined value or more, and fluidization of the filtered particles is started. Even if the filtration particles at the top of the particle packed bed are fluidized beyond the speed, the partition plate prevents the fluidization of the filtration particles, so that the gas superficial velocity can be increased to ensure high dust collection efficiency, and the pressure loss is reduced. Significantly lower There is an effect of.

According to a second aspect of the present invention, there is provided an exhaust gas collecting apparatus for removing high-temperature exhaust gas containing dust by passing the same through a filtration medium, wherein the exhaust gas duct through which high-temperature exhaust gas containing dust flows. The lower side portion is connected to the discharge side, has a discharge port on the upper side, the diameter of the lower gas inlet portion is small, and the diameter of the upper gas outlet portion is large. A particle-packed layer is formed by loading, and high-temperature exhaust gas is passed through a particle-packed layer having a small diameter on the lower gas inlet side and a large diameter on the upper gas outlet side to remove dust from the exhaust gas. So
Even if the gas superficial velocity in the particle packed bed is increased to the fluidization start speed on the gas inlet side, the gas inlet side of the particle packed bed is at the lower part, so there is no risk of particles being fluidized, and the gas outlet of the particle packed bed On the side, the gas flow rate is equal to or less than the fluidization start speed, and does not exceed the fluidization start speed of the filtered particles, so that the fluidization of the filtered particles can be prevented, so that the gas superficial velocity can be increased to secure high dust collection efficiency, Moreover, there is an effect that the pressure loss is significantly reduced.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an exhaust gas dust collecting apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a graph showing a state in which the dust collection efficiency changes with respect to the gas superficial velocity of the particle packed bed.

FIG. 3 is a schematic sectional view of an exhaust gas dust collecting apparatus according to Embodiment 2 of the present invention.

FIG. 4 is an explanatory diagram showing a conventional coal gasifier including a flue gas dust collector.

[Description of Signs] 1 Exhaust gas duct 2 Particle filling furnace 3 Particle filling layer 5 Partition plate 10 Fixed particles

Claims (2)

[Claims] An exhaust gas collecting device for removing high-temperature exhaust gas containing dust by passing the same through a filtration medium, wherein a lower side portion is connected to an exhaust side of an exhaust gas duct through which high-temperature exhaust gas containing dust flows. , A particle-filling furnace having an outlet above, a particle-filled bed formed by loading solid particles as a filtration medium into the particle-filling furnace, A dust collector for exhaust gas, comprising: a partition plate capable of contacting ventilation. 2. An exhaust gas collecting apparatus for removing high-temperature exhaust gas containing dust by passing the same through a filtration medium, wherein a lower side portion is connected to an exhaust side of an exhaust gas duct through which high-temperature exhaust gas containing dust flows. A particle-filling furnace having a discharge port at the top, a small diameter at the lower gas inlet, and a large diameter at the upper gas outlet; loading solid particles as a filtration medium into the particle-filling furnace; An exhaust gas dust collecting apparatus comprising: a particle packed layer having a small diameter on a gas inlet side and a large diameter on an upper gas outlet side.