Dust collector

Abstract

A dust collector 1 comprises: a gas introduction part 10 which introduces a gas flow (F1) including a collection object in the gravity direction; a gas inversion part 20 which inverts the gas flow (F1) introduced from the gas introduction part 10 in a direction inverse to the gravity direction and has two or more gas flow division regions along the flow direction of the inverted gas flow; and a discharge part 30 which is provided below the gas introduction part 10 and / or below the gas inversion part 20 and discharges the collection object downward.

Description

Dust collection device

[0001] The present invention relates to a dust collection device. For example, it relates to a dust collection device for collecting dust (solid matter) in the exhaust gas discharged from a combustion furnace.

[0002] Patent Document 1 discloses an unburned ash classification facility using a multi - cyclone. Since a micro - cyclone is used, a locally high flow velocity occurs, resulting in a large pressure loss. Also, because solid matter is centrifugally separated, the wear of the device is severe and the maintenance cost is high.

[0003] Patent Document 2 discloses a wood pellet combustion device. Combustion air containing ash from the combustion exhaust port is guided to a suction fan and then supplied to a centrifugal separation device. The exhaust air is reversed on an arc surface, and the ash swirling along the arc surface migrates to an ash duct and accumulates in an ash collection container without ventilation to the outside. The combustion air from which ash is separated on the arc surface of the centrifugal separation device flows through an exhaust duct and is discharged outside the machine from an exhaust duct. Due to the ash hitting the arc surface of the centrifugal separation, the wear is severe.

[0004] Patent Document 3 discloses a white powder removal device. A collection plate for recovering white powder is arranged. The collection plate is arranged such that the plate surface is orthogonal to the flow direction of the atmosphere flowing in the suction duct portion, or the collection plate is inclined upstream with respect to the flow direction. That is, it aims to actively apply the white powder to the collection plate, resulting in a large pressure loss and severe wear between the upstream and the downstream.

[0005] Patent Document 4 discloses a rectifying device for an exhaust gas duct. A plurality of rectifying plates are arranged concentrically with the bend in the exhaust gas duct through which the exhaust gas discharged from a coal - fired boiler flows. Coal ash removal holes are drilled in the horizontal part and the inclined part close to the horizontal of the rectifying plate. The rectifying plate is arranged at a position where the flow of the exhaust gas changes from the vertical downward direction to the horizontal direction, and the configuration is such that coal ash is accumulated on the rectifying plate.

[0006] Patent Document 5 discloses a fly ash removal device. Adhesion plates of a predetermined size are erected vertically from the left and right side walls on the inner circumferential surface of the inlet pipe as obstruction plates that hinder the flow of high-temperature exhaust gas. The purpose is to actively bring fly ash onto the adhesion plates, but there is a large pressure loss between the upstream and downstream sides, and wear is severe.

[0007] Patent Document 6 discloses a dust collection device with variable collection efficiency. The dust collection device consists of a cylindrical body and a hopper section connected to the lower part of the cylindrical body. Inside the cylindrical body, a vertically movable damper (obstruction plate) for variable collection efficiency is provided. The damper for variable collection efficiency functions as an obstruction plate and is configured to actively bring unburned ash into the damper, resulting in significant wear.

[0008] Utility Model Publication No. 5-96735 Patent No. 4082617 Patent No. 6976381 Japanese Patent Application Publication No. 08-075138 Patent No. 3901453 Patent No. 2898625

[0009] However, the above-mentioned Patent Documents 1, 3, 5, and 6 all suffer from high pressure loss and severe wear. Patent Document 2 suffers from severe wear, and Patent Document 4 has a complex structure that accumulates coal ash on the rectifier plate.

[0010] Therefore, the purpose of this disclosure is to provide a dust collection device that does not use conventional multi-cyclone technology and can reduce pressure loss and wear of the device.

[0011] The dust collection device (1) of this disclosure includes a gas introduction unit (10; gas introduction region Ein) for introducing a gas flow (F1) containing the object to be collected (solid matter) in the direction of gravity (from top to bottom), a gas reversal unit (20) for reversing the gas flow (F1) introduced from the gas introduction unit (10) in the direction opposite to the direction of gravity (from bottom to top), and having two or more gas flow fractionation regions (Ei) along the flow direction of the reversed gas flow (along the direction that does not oppose the gas flow), and a discharge unit (30; collected material discharge region Eex) provided below the gas introduction unit (10) and / or below the gas reversal unit (20) for discharging the object to be collected downward.

[0012] The gas inlet (10) may have a rectangular cross-sectional shape in plan view. When the gas inlet (10) and the gas reversal section (20) are arranged side by side, the gas inlet (10) and the gas reversal section (20) may be arranged in a substantially Y-shape in a front view. When the gas inlet (10) and the gas reversal section (20) are arranged side by side, the shape in the depth direction from the front view may be rectangular. Similarly, the discharge section (30) may have a rectangular shape in the depth direction. The internal cross-sectional area (rectangular cross-sectional area) of the gas inlet (10) may be the same as, or larger than, the internal cross-sectional area (rectangular cross-sectional area) of the discharge section (30).

[0013] The two or more gas flow fractionation regions (Ei) may have regions at the boundary between adjacent gas flow fractionation regions through which gas flows flow in or out of each other. For example, a plate-shaped louver may have a penetration, through which the gas flow passes. The two or more gas flow fractionation regions (Ei) may be configured by arranging one or more plate-shaped louvers (kj), or by arranging hollow cylindrical bodies with rectangular, circular, or polygonal cross-sections. The two or more gas flow fractionation regions (Ei) may have the same or different sizes and gas flow angles. "j" is from 1 to n, and "i" is from 1 to n+1.

[0014] When the plate-shaped louvers (kj) form the two or more gas flow fractionation regions (Ei), the louvers (kj) are arranged in parallel, and the spacing between them (Di) may be equal or different at each stage, the length in the gas flow direction (Lj) and the length in the depth direction (Wj) of each louver (kj) may be the same or different, and the angle (αj) of each louver (kj) with respect to the horizontal may be the same or different. Each louver (kj) may be parallel to the direction that the gas reversal section (20) is directed diagonally upward.

[0015] The depth (width) of the dust collection device (1) should be greater than or equal to the length that does not affect the gas flow due to wall friction. If the width (depth) of the device is increased, a structure to support the louvers (kj), etc. (intermediate walls or support columns) may be provided, depending on the strength of the device, to the extent that it does not affect the gas flow.

[0016] The gas introduction section (10) may be connected to the gas reversal section (20) at an acute connection angle γ (15° to 60°). The gas introduction section (10) may have a side wall facing the gas reversal section (20) that extends vertically to the discharge section (30). The gas introduction section (10) may be inclined diagonally downward in a straight line overall and connected to the gas reversal section (20) at an acute angle (for example, connection angle γ = 15° to 60°).

[0017] The gas introduction section (10) may have a vertical side wall section (10a) that extends vertically downward and a side wall that faces the gas reversal section (20), and an inclined side wall section (10b) that slopes toward the gas reversal section (20). The inclined side wall section (10b) may extend from a starting point (101a) of the inclination starting from the lower end of the vertical side wall section (10a) to a ending point (101b) of the inclination toward the discharge section (30). The inclination angle (β) of the inclined side wall section (10b) is the angle from the horizontal line to the outer surface of the side wall, and is, for example, smaller than 90° (vertical with no inclination).

[0018] The starting point of the inclination of the inclined side wall (10b) (101a) may be located below the starting point of the upper connection of the gas reversal section (20) (202a).

[0019] The gas reversal section (20) may have a first space (21) formed diagonally upward from the gas introduction section (10), and a second space (22) extending upward or laterally from the first space (21). "Above the first space (21)" may include vertical and inclined at less than 45° from the vertical. "Laterally from the first space (21)" may include horizontal and inclined at less than 45° from the horizontal.

[0020] The first space (21) may extend diagonally upward from the upper connection start point (202a) and lower connection start point (201a), which are located where it connects to the gas introduction section (10), to the upper connection end point (202b) and lower connection end point (201b). The angle α between the downward sloping side wall (21a) extending from the lower connection start point (201a) to the lower connection end point (201b) and the horizontal line may be greater than 0° and less than 90°, and preferably 40° to 80°. The angle α between the upward sloping side wall (21b) extending from the upper connection start point (202a) to the upper connection end point (202b) and the horizontal line may be greater than 0° and less than 90°, and preferably 40° to 80°. The downward sloping side wall (21a) and the upward sloping side wall (21b) may be arranged parallel to each other vertically.

[0021] In the first space (21), the length of the upper inclined side wall (21b) from the upper connection start point (202a) to the upper connection end point (202b) may be the same as, or shorter than, the length of the lower inclined side wall (21a) from the lower connection start point (201a) to the lower connection end point (201b).

[0022] Each louver (kj) may be positioned within the first space (21) with respect to a first imaginary line drawn from the upper connection start point (202a) to the lower connection start point (201a). Each louver (kj) may be positioned between a second imaginary line drawn vertically downward from the upper connection start point (202a) and the first imaginary line.

[0023] (Effects) (1) Large-particle fly ash containing a large amount of unburned material as solid matter can be separated and recovered. (2) Compared to conventional technology (multi-cyclone), the pressure loss is very small, so the power of the gas flow generating device (e.g., induced draft fan) can be reduced, and the operating cost of the equipment can be reduced. (3) Compared to conventional technology (multi-cyclone), the device structure is simpler, so the manufacturing cost is lower. (4) Compared to conventional technology (multi-cyclone), the device structure is simpler, so it is easier to maintain and maintenance costs can be reduced. (5) Compared to conventional technology (multi-cyclone), the local flow velocity is lower, so wear on the equipment is reduced, the frequency of maintenance can be reduced, and maintenance costs can be reduced.

[0024] This figure shows a dust collector according to Embodiment 1. (a) is a three-dimensional external view of the dust collector. (b) is a front view of the dust collector. (c) is a diagram illustrating each inclination angle. HVL indicates a horizontal dashed line. (d) is a diagram illustrating the size of the louvers. L is the length in the gas flow direction, and W is the depth length. This figure shows a dust collector according to Embodiment 2. This figure shows an example of a louver from another embodiment. Examples of angles α = 60° in (a) and α = 70° in (b) are shown. This figure shows an example of a louver from another embodiment. An example where the length of 21a in (a) is shorter than the length of 21a in (b). An example where the length of 21b in (a) is shorter than the length of 21b in (b). This figure shows an example of a louver from another embodiment. An example showing the difference in the number of louvers and gas flow fractionation regions is shown. This figure shows an example of a louver from another embodiment. An example showing the same number of louvers and gas flow fractionation regions, but with a different louver spacing D is shown. This figure shows an example of a louver from another embodiment. This shows examples of different arrangement angles of louvers or gas flow fractionation regions. This figure shows an example of a louver in a different embodiment. This shows examples of different lengths of louvers or gas flow fractionation regions. This figure shows an example of a dust collector in a different embodiment. (a) shows an example of a straight-shaped gas inlet. (b) shows an example of an inclined gas inlet. This figure shows an example of a dust collector in a different embodiment. (a) shows a front view, (b) shows a left side view, and (c) shows a right side view.

[0025] Some embodiments of the present invention are described below. The embodiments described below illustrate just one example of the present invention. The present invention is not limited in any way to the embodiments described below, and includes various modifications that are implemented without changing the gist of the present invention.

[0026] (Embodiment 1) Figure 1 shows a dust collection device 1 of Embodiment 1. The dust collection device 1 includes a gas introduction section 10, a gas reversal section 20, and a discharge section 30.

[0027] The gas introduction section 10 introduces a gas flow F1 containing the object to be collected (solid matter) in the direction of gravity. The gas flow F1 flows downward in the gas introduction region Ein of the internal space. The gas introduction section 10 has vertical sidewall sections 10a and 10a' that extend vertically downward and a side wall section 10b that slopes toward the gas reversal section 20, facing the gas reversal section 20. The sloped sidewall section 10b extends from a starting point 101a that starts from the lower end of the vertical sidewall section 10a to a terminating point 101b on the discharge section 30 side.

[0028] The inclination angle β of the inclined side wall portion 10b is the angle from the horizontal line to the outer surface of the side wall, and is, for example, less than 90°. In this embodiment, the inclination angle β is 80°.

[0029] The gas reversal section 20 reverses the gas flow F1 introduced from the gas introduction section 10 in a direction opposite to the direction of gravity, and has two or more gas flow fractionation regions Ei along the flow direction of the reversed gas flow F1. The gas flow fractionation regions Ei are formed by arranging plate-shaped louvers kj. In Embodiment 1, there are five plate-shaped louvers k1 to k5, and six gas flow fractionation regions E1 to E6 are formed. The five plate-shaped louvers k1 to k5 are arranged parallel to each other, and the distance D between them is the same.

[0030] The gas reversal section 20 has a first space 21 formed diagonally upward from the gas introduction section 10, and a second space 22 extending vertically upward from the first space 21. The first space 21 extends diagonally upward from the upper connection start point 202a and the lower connection start point 201a, which are positions where it is connected to the gas introduction section 10 in a front view, to the upper connection end point 202b and the lower connection end point 201b. The second space 22 has side walls 22a and 22a' that extend vertically upward from the lower connection end point 201b and the upper connection end point 202b.

[0031] In this embodiment, the angle α between the downward-sloping side wall 21a extending from the lower connection start point 201a to the lower connection end point 201b and the horizontal line is 60°. The downward-sloping side wall 21a and the upward-sloping side wall 21b are arranged parallel to each other vertically. In the first space 21, the length of the upward-sloping side wall 21b from the upper connection start point 202a to the upper connection end point 202b is shorter than the length of the downward-sloping side wall 21a from the lower connection start point 201a to the lower connection end point 201b. Each louver kj is positioned between a first imaginary line drawn from the upper connection start point 202a to the lower connection start point 201a and a second imaginary line drawn vertically downward from the upper connection start point 202a. In a front view, the connection angle γ formed by the gas introduction section 10 and the gas reversal section 20 is between 20° and 45°.

[0032] The discharge section 30 is located below the gas inlet section 10 and below the gas reversal section 20, and discharges the collected material downward. The discharge section 30 has a collected material discharge area Eex. The internal cross-sectional area (rectangular cross-sectional area) of the discharge section 30 is smaller than the internal cross-sectional area (rectangular cross-sectional area) of the gas inlet section 10.

[0033] The dust collector 1 of this embodiment can be used to treat exhaust gas sent from a combustion furnace. The fly ash contained in the exhaust gas generated by the combustion of fuel has various particle sizes, but unburned material is distributed in areas with larger particle sizes, while completely burned ash has smaller particle sizes. According to the dust collector 1 of this embodiment, when the gas flow F1 is reversed in the gas reversal section 20, the fly ash particles deviate from the airflow due to the inertial force of the fly ash particles, collide with each louver kj, and lose their velocity, causing the particles to be sent to the discharge section 30 by gravity and discharged. Whether particles that have lost velocity are sent to the discharge section 30 below the gas inlet section 10 by gravity, or whether they are carried back to the gas reversal section 20 on the gas flow F1, mainly depends on the mass of the particles. Fly ash with a large mass (fly ash with a large particle size and a high distribution of unburned material) is discharged to the discharge section 30, while fly ash with a small mass (fly ash with a small particle size and a high distribution of ash material) flows to the gas reversal section 20. The particle recovery efficiency is influenced by the flow rate distribution of the gas flow F1 flowing through the gas flow fractionation regions Ei separated by each louver kj. It is considered that the recovery efficiency is better when the flow rates in each gas flow fractionation region Ei are as uniform as possible. Therefore, in this embodiment, each louver kj is arranged in parallel and the spacing D is the same so that the cross-sectional area of ​​each gas flow fractionation region Ei is the same. The inclined side wall section 10b with an inclination angle β rectifies the gas flow F1 when it is sent to each louver kj, taking into account the pressure loss.

[0034] (Embodiment 2) The dust collection device 1 of Embodiment 2, shown in Figure 2, differs from the dust collection device 1 of Embodiment 1 in the configuration of the second space 22, while the other components are the same. The second space 22 extends horizontally from the first space 21. The second space 22 includes side walls 22a and 22a' that extend horizontally from the lower connection end point 201b and the upper connection end point 202b.

[0035] (Another Embodiment) Figures 3A to 3E show louvers of an alternative embodiment. (1) Figure 3A shows that the angle α between the downward sloping side wall 21a and the horizontal line is 60° in the left figure (a) and a larger 70° in the right figure (b).

[0036] (2) Figure 3B shows that the length of the upper inclined side wall 21b and the length of the lower inclined side wall 21a in the left figure (a) are smaller than those in the right figure (b).

[0037] (3) Figure 3C shows the difference in the number of louvers or gas flow fractionation regions. Depending on the cross-sectional area or volume of the first space 21, it can be set considering the effect of pressure loss of the gas flow F1. (a) shows an example with 5 louvers, 6 gas flow fractionation regions, and the same louver spacing D in a parallel arrangement. (b) shows an example with 2 louvers, 3 gas flow fractionation regions, and the same louver spacing D in a parallel arrangement. (c) shows an example with 11 louvers, 12 gas flow fractionation regions, and the same louver spacing D in a parallel arrangement. (4) Figure 3D shows the difference in louver spacing D. The spacing D may differ in only a part, or the upper or lower spacing D may differ. (d) shows an example with 4 louvers, 5 gas flow fractionation regions, and a parallel arrangement where the louver spacing D is narrower at the top than at the bottom. (e) shows an example with 4 louvers, 5 gas flow fractionation regions, and a parallel arrangement where the louver spacing D is narrower at the bottom.

[0038] (5) Figure 3E shows the difference in the arrangement angle of the louvers or gas flow fractionation areas. In Embodiment 1, the inclination angle of each louver is the same as the inclination angle α of the gas reversal section 20. In another embodiment, the inclination angles of each louver may be different. In addition to fixed inclination angles of the louvers, a structure in which the angle can be varied like a damper may be used to change the fly ash collection rate even during operation of the device. Figure 3E shows an example in which there are 5 louvers, 6 gas flow fractionation areas, the angle α is larger below the louvers, and the louver spacing D is smaller with the difference in angle.

[0039] (6) Figure 3F shows the difference in length of the louvers or gas flow fractionation regions. In Embodiment 1, the length L of each louver was the same. (f) is an example with five louvers of shorter length than in Figure 3C(a), six gas flow fractionation regions, and the same louver spacing D in a parallel arrangement. (g) is an example with five louvers of shorter length at the bottom, six gas flow fractionation regions, and the same louver spacing D in a parallel arrangement. In (g), the length L of each louver may be configured to be different, with the lower louvers being shorter. (f) is a configuration with a shorter louver length L than in Embodiment 1.

[0040] (7) Figure 4(a) shows a configuration in which the gas introduction section 10 does not have an inclined side wall section 10b and extends to the discharge section 30. (8) Figure 4(b) shows a configuration in which the gas introduction section 10 is generally inclined diagonally downward in a straight line. The gas introduction section 10 has a first inclined side wall section 10c whose side wall facing the gas reversal section 20 is inclined downward from the vertical, and a second inclined side wall section 10d whose angle of inclination from the vertical is different from that of the first inclined side wall section 10c. The second inclined side wall section 10d extends from an inclination start point 101c that starts from the lower end of the first inclined side wall section 10b to an inclination end point 101d on the discharge section 30 side. At the inclination start point 101c, the angle θ1 from the horizontal to the first inclined side wall section 10c may be 0 degrees or more and less than 90 degrees. At the end point of the incline 101d, the angle θ2 from the horizontal to the second inclined side wall 10d may be 60 degrees or more and 90 degrees.

[0041] (9) In Figures 1 and 5, the planar cross-sectional shape of the second space 22 in a plan view is rectangular. (a) In a front view, the external shape of the gas introduction section 10 and the gas reversal section 20 (especially the first space section 21) is roughly Y-shaped. (b) (c) In the left and right side views, the external appearance of the gas introduction section 10 and the gas reversal section 20 are rectangular. As shown in Figure 5, a hopper-shaped constriction 34 may be provided below the discharge section 30 to concentrate the discharge points.

[0042] 1 Dust collector 10 Gas inlet 20 Gas inversion section 30 Discharge section

Claims

1. A dust collection device comprising: a gas introduction section for introducing a gas flow containing the object to be collected in the direction of gravity; a gas reversal section that reverses the gas flow introduced from the gas introduction section in a direction opposite to the direction of gravity and has two or more gas flow fractionation regions along the flow direction of the reversed gas flow; and a discharge section provided below the gas introduction section and / or below the gas reversal section for discharging the object to be collected downward.

2. The dust collection device according to claim 1, wherein the two or more gas flow fractionation regions are configured to have one or more plate-shaped louvers or to have hollow cylindrical bodies.

3. The dust collection device according to claim 1 or 2, wherein the gas introduction section has a vertical side wall portion that extends vertically downward and a side wall portion that slopes toward the gas reversal section, facing the gas reversal section.

4. The dust collection device according to any one of claims 1 to 3, wherein the gas reversal section has a first space formed diagonally upward from the gas introduction section and a second space extending upward or laterally from the first space.

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