JP2009202142A - Dust removal apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dust removal apparatus for removing dust from an exhaust gas which is space-saving, structually simple, and operable at a low cost. <P>SOLUTION: Provided is a dust removal apparatus for removing dust (such as, particulate matter of powdery dust, fly ash, or pulverized coal) from a duct 1 through which a gas containing the dust passes, wherein a baffle plate 2 is installed in that passage part of the inside duct wall which is situated downstream, in the gas flow direction, of a duct bent part 6 formed by an angle change or curving of the duct 1 and on which the gas flow exerts a centrifugal force, the dust moved to the side of the passage part is trapped by the baffle plate 2, and an openable and closable port 3 is formed in a position 4 where the trapped dust deposits. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a duct through which a gas containing particulate matter (hereinafter referred to as dust) such as dust, fly ash, and pulverized coal flows, such as an exhaust gas passage or flue of a combustion furnace, or pulverized coal mixed with air. The present invention relates to a dust removing device that removes dust from a duct that functions as a conveying path.

  Conventionally, exhaust gas containing particulate matter (hereinafter referred to as dust) such as dust, fly ash, and pulverized coal has been discharged in many cases, such as waste solid fuel conversion facilities, waste incinerators, and general incinerators. Since the surrounding environment deteriorates due to the dust, the dust is removed when exhausting in order to prevent the deterioration of the environment. Since the exhaust gas containing dust is high in temperature, it may ignite halfway and sent to a dust collector installed downstream. One device for removing this dust is a cyclone. A cyclone is a kind of dust removing device that centrifuges dust from a mixed phase flow of dust or solid particles and a gas body, that is, a dust-containing airflow, but it is difficult to secure an installation space and costs high.

  Therefore, Patent Document 1 (Japanese Patent Laid-Open No. 10-230116) that removes dust contained in exhaust gas by means other than a dust collector is disclosed as simpler dust removal. Patent Document 1 attempts to separate and remove dust by increasing the cross-sectional area of a flow path through which exhaust gas containing dust flows to reduce the exhaust gas flow velocity. Specifically, in an exhaust gas passage structure of a continuous melting furnace that melts powdered waste or ash at a high temperature, a tapered connection part connected to the upper part of the melting furnace is provided at the lower part, and dust removing means is provided. A dust separation chamber provided in the upper portion is provided, and a duct having a smaller diameter than the upper diameter of the separation chamber is connected above the dust separation chamber, and dust separation is promoted by reducing the flow velocity.

Further, in Patent Document 2 (Japanese Patent Laid-Open No. 10-183232), a lance having a nozzle for blowing a gas body toward the surface of the water pipe of the gas cooler is provided in the gas cooler of the vacuum degassing apparatus or its adjacent duct. An invention for removing dust is disclosed. In patent document 2, the dust adhering to the water pipe of the gas cooler in which exhaust gas flows is supplied to the lance and blown to remove dust attached to the surface of the water pipe. As the gas material used here, steam, nitrogen gas, air, inert gas or CO ₂ or the like, such as Ar and the like.

JP-A-10-230116 Japanese Patent Laid-Open No. 10-183232

However, in the invention disclosed in Patent Document 1, although it is a structure for dust removal that is structurally simple and can reduce installation space, a specific method for collecting and removing small particle size dust has not been proposed. However, even if dust having a relatively large particle size can be separated by reducing the exhaust gas flow rate, it is considered that it is insufficient for separating the small particle size dust.
Further, in the invention disclosed in Patent Document 2, when spraying is performed continuously, the consumption of the gas body increases and costs increase. Further, in order to solve the problem of cost, when spraying is performed at regular intervals, efficiency is lowered and dust accumulation proceeds.

  Therefore, in view of the above-described problems of the prior art, an object of the present invention is to provide a dust removing device that removes dust in exhaust gas that is space-saving, structurally simple and can be operated at low cost.

Therefore, in order to solve such a problem, the present invention provides a dust removing apparatus for removing dust from a duct through which a gas containing dust (flying ash), pulverized coal, etc. (hereinafter referred to as dust) flows.
A baffle plate is installed at a flow path portion where a centrifugal force due to gas flow acts on a duct inner wall portion located downstream of the duct bending portion formed by an angle turning or bending of the duct, Dust shaken by the baffle plate toward the flow path portion where the centrifugal force acts is collected, and an opening that can be opened and closed is provided at the collected dust accumulation position.

As a result, when the exhaust gas containing dust passes through the duct bend, dust having a large particle size among dust particles in the exhaust gas is shaken and accumulated outside the curve by centrifugal force. Dust with a small particle size that does not accumulate at the bent part of the duct is also a baffle plate installed in the flow path part where the centrifugal force due to the gas flow on the duct inner wall part located downstream of the duct bent part in the gas flow direction acts. By this, it can collide and drop by gravity and can be collected.
In addition, since an opening that can be opened and closed is provided at the dust accumulation position, the dust can be extracted and removed from the opening when dust accumulation becomes significant.

Further, in the present invention, the opening forming position is the angle turning position of the duct bending portion located at the upstream side in the gas flow direction from the baffle plate mounting position, the maximum curvature portion of the bending portion, or gravity at the inflection point. It is a position.
An opening is provided at a position where dust is accumulated as described above, and the accumulated dust is intermittently removed so that the dust separated from the exhaust gas does not return to the exhaust gas flow path again.

Furthermore, in a dust removing device that removes dust from a duct through which gas containing dust, fly ash, pulverized coal, etc. (hereinafter referred to as dust) flows,
A buffer portion that is widened in the direction of gravity is provided at a portion where the flow path is formed substantially linearly in the inclination direction or the horizontal direction of at least 45 ° or less, and downstream of the buffer portion in the gas flow direction A baffle plate is installed at a position (preferably the end side position), and the baffle plate is installed at a height higher than the baffle plate so that the baffle plate bypasses the gas in the direction of gravity and flows into the flow path located downstream from the buffer unit end. In addition to setting the height and width range, the dust is collected on the buffer bottom wall side by centrifugal force acting on the dust during the detour, and an opening that can be opened and closed is provided at the dust accumulation position on the buffer bottom wall side It is characterized by that.

By providing the buffer part in the gas flow path in this way, the flow is separated at the inlet part of the buffer part where the cross-sectional area of the gas flow path increases rapidly, and a stagnation part is formed and dust is easily collected, Dust is deposited on the buffer. In addition, dust that is not deposited in the above-described separation zone but remains on the gas flow path collides with a baffle plate installed at a downstream position in the gas flow direction of the buffer unit and is collected because it falls by gravity. it can.
Further, by providing an opening at the dust accumulation position, when dust accumulation becomes significant, the dust can be extracted and removed from the opening.

In addition, the baffle plate has a length extending downward from the upper wall of the buffer portion located downstream of the buffer portion in the gas flow direction so as to block the downstream flow path in the gas flow direction (projection direction). To do.
Thus, the baffle plate installed at the downstream position in the gas flow direction of the buffer portion closes the gas flow path and promotes the separation and removal of dust in the exhaust gas.

As described above, according to the present invention, when the exhaust gas containing dust passes through the duct bend, dust having a large particle size among the dust particles in the exhaust gas is shaken and accumulated outside the curve by centrifugal force. . Dust with a small particle size that does not accumulate at the bent part of the duct is also a baffle plate installed in the flow path part where the centrifugal force due to the gas flow on the duct inner wall part located downstream of the duct bent part in the gas flow direction acts. By this, it can collide and drop by gravity and can be collected.
Furthermore, by providing a buffer part in the gas flow path, the flow is separated at the inlet part of the buffer part where the cross-sectional area of the gas flow path suddenly increases, and a stagnation part is formed and dust is easily collected. Dust is deposited on the part. In addition, dust that is not deposited in the above-described separation zone but remains on the gas flow path collides with a baffle plate installed at a downstream position in the gas flow direction of the buffer unit and is collected because it falls by gravity. it can.
The dust collected and accumulated in this way can be removed by removing the dust from the opening when dust accumulation becomes significant by the openable / closable opening provided in the duct. .

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

FIG. 1 is a schematic side view showing the dust removing apparatus according to the first embodiment. In FIG. 1, 1 is a duct (gas flow path) through which a gas containing dust (dust particles such as dust, fly ash, and pulverized coal) flows, 2 is a baffle plate provided in the duct, and 3 is an opening. 4 is a dust accumulation position, and 6 is a bent part of the duct formed by an angle change or curvature of the duct 1.
The duct bent portion 6 is formed by changing the angle or bending of the duct 1, and here, for example, a bent portion formed by bending the duct 1 at a right angle is shown.

When the dust in the exhaust gas flowing through the duct 1 passes through the bent portion 6 of the duct, it is swung to the outside of the bend due to centrifugal force and accumulated at the dust accumulation position 4. The dust swung to the outside of the bend due to the centrifugal force has a relatively large particle size among the dusts contained in the exhaust gas, and therefore falls and settles without riding on the flow of the exhaust gas.
On the other hand, although dust with a small particle diameter is swung to the outside of the bend, it may be considered that it does not fall and settle and does not accumulate on the flow of exhaust gas, and a baffle plate 2 is provided to collect this. By causing the dust to collide with the baffle plate 2 that blocks the flow path of the exhaust gas containing dust, the dust falls and accumulates at the dust accumulation position 4, so that the separation can be promoted.

In addition, the baffle plate 2 is provided in the flow path part where the centrifugal force by the gas flow of the duct inner wall part located in the gas flow direction downstream of the duct bending part 6 acts. The installation position of the baffle plate 2 is such that the gas flow path diameter (gas flow path width) is D and the length from the duct bent portion 6 to the baffle plate installation position is L, so that the flow path is not blocked L ≦ 1D to 20D In particular, L ≦ 3D is more preferable from the relationship with the flow rate of exhaust gas.
The height H of the baffle plate 2 is preferably 1 / D or more, which is half of the gas flow path diameter D, and the area of the baffle plate 2 is preferably at least half of the flow path area of the duct 1.

  The dust accumulated at the dust accumulation position 4 is extracted and removed by the opening 3 formed in the duct. The opening 3 is normally closed, and is opened when dust accumulation at the dust accumulation position 4 becomes significant, and dust is intermittently removed. In this way, dust can be separated and removed from the exhaust gas containing dust.

  FIG. 2 is a schematic side view illustrating the dust removing apparatus according to the second embodiment. As in FIG. 1, 1 is a duct (gas flow path) through which a gas containing dust (dust particles such as dust, fly ash, pulverized coal) flows, 2 is a baffle plate provided in the duct, 3 1 is an opening, 4 is a dust accumulation position, and 6 is a duct bend formed by an angle change or curve of the duct 1, which has almost the same configuration as FIG. It differs in that it flows from top to bottom.

  As shown in FIG. 2, when the dust in the exhaust gas flowing through the duct 1 passes through the duct bending portion 6, it is shaken to the outside of the bending by centrifugal force and is accumulated at the dust accumulation position 4 by gravity. In the case of FIG. 2, dust having a small particle diameter is also swung to the outside of the bend and accumulated at the dust accumulation position 4 by gravity. Since the duct accumulation position 4 is on the baffle plate 2, the dust is intermittently removed by opening the opening 3 so that the dust separated from the exhaust gas does not return to the exhaust gas flow path again.

FIG. 3A is a schematic side view showing the dust removing apparatus according to the third embodiment, and FIG. 3B is a cross-sectional view taken along the line AA in FIG.
In FIG. 3, 1 is a duct (gas flow path) through which a gas containing dust (dust particles such as dust, fly ash and pulverized coal) flows, 2 is a baffle plate, 3 is an opening, 8 is a dust accumulation position, and 5 is a buffer formed by widening the duct 1.

In the exhaust gas flowing through the duct 1, the flow is separated at the inlet portion of the buffer 5 where the cross-sectional area of the gas flow path suddenly increases, and a stagnation portion is formed and dust is easily collected. Dust is deposited at the deposition position 7.
On the other hand, the dust (small particle size dust) that is not deposited in the separation zone but remains on the gas flow path collides with the baffle plate 2 installed downstream of the buffer 5 in the gas flow direction and falls by gravity. To do. For this reason, dust accumulates at the dust accumulation position 8 and can be collected. The dust accumulated in the dust accumulation positions 7 and 8 in this way is removed by opening the opening 3 when the accumulation becomes significant.

As shown in FIG. 3A, the baffle plate 2 is installed at a downstream position in the gas flow direction of the buffer 5 in order to collide with dust, and in the gas flow direction (projection direction) from the upper wall of the buffer 5. It is desirable to set the downward extension length so as to block the downstream channel. That is, the height H of the baffle plate 2 is larger than the gas flow path diameter D, and the cross-sectional area of the baffle plate 2 is larger than the cross-sectional area of the duct 1 (FIG. 3B).
Thus, by providing the baffle plate 2 together with the buffer 5, the dust in the exhaust gas is separated and removed.

  According to the present invention, a duct through which gas containing dust (dust, fly ash, pulverized coal, etc.) flows, such as an exhaust gas passage or flue of a combustion furnace, or pulverized coal is mixed with air or the like. It is useful as a dust removing device that removes dust from a duct that functions as a conveying path.

1 is a schematic side view showing a dust removing device according to Embodiment 1. FIG. It is a schematic side view which shows the dust removal apparatus which concerns on Example 2. FIG. (A) is a schematic side view which shows the dust removal apparatus which concerns on Example 3, (b) is sectional drawing which follows the AA line of Fig.3 (a).

Explanation of symbols

1 Duct (gas flow path)
2 Baffle plate 3 Opening 4 Dust accumulation position 5 Buffer 6 Duct bent part

Claims (4)

In a dust removal device that removes dust from a duct through which gas containing dust, fly ash, pulverized coal, etc. (hereinafter referred to as dust) flows,
A baffle plate is installed at a flow path portion where a centrifugal force due to gas flow acts on a duct inner wall portion located downstream of the duct bending portion formed by an angle turning or bending of the duct, A dust removing apparatus characterized by collecting dust shaken by a baffle plate toward a flow path portion where a centrifugal force acts, and providing an openable / closable opening at a position where the collected dust is accumulated.   The opening forming position is an angle turning position of a bent part of the duct positioned upstream of the baffle plate mounting position or a maximum curvature part of the bent part, or a position where gravity acts at the inflection point. The dust removing device according to claim 1, wherein In a dust removal device that removes dust from a duct through which gas containing dust, fly ash, pulverized coal, etc. (hereinafter referred to as dust) flows,
A buffer portion that is widened in the direction of gravity is provided at a portion where the flow path is formed substantially linearly in the inclination direction or the horizontal direction of at least 45 ° or less, and downstream of the buffer portion in the gas flow direction A baffle plate is installed at a position (preferably the end side position), and the baffle plate is installed at a height higher than the baffle plate so that the baffle plate bypasses the gas in the direction of gravity and flows into the flow path located downstream from the buffer unit end. In addition to setting the height and width range, the dust is collected on the buffer bottom wall side by centrifugal force acting on the dust during the detour, and an opening that can be opened and closed is provided at the dust accumulation position on the buffer bottom wall side A dust removing device characterized by that. The length of the baffle plate extending downward is set so as to block the downstream flow path in the gas flow direction (projection direction) from the upper wall of the buffer portion located downstream of the buffer portion in the gas flow direction. Item 4. A dust removing apparatus according to Item 3.

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