Dust collection device

Abstract

To provide a dust collection device that does not use a multi-cyclone and reduces pressure loss and wear on the device. [Solution] The dust collection device 1 includes a gas introduction unit 10 that introduces a gas flow F1 containing the material to be collected in the direction of gravity, a gas reversal unit 20 that reverses the gas flow F1 introduced from the gas introduction unit 10 in the 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 unit 30 provided below the gas introduction unit 10 and / or below the gas reversal unit 20 that discharges the material to be collected downward.

Description

[Technical Field]

[0001] This invention relates to a dust collection device. For example, it relates to a dust collection device for capturing dust (solid matter) in exhaust gas emitted from a combustion furnace. [Background technology]

[0002] Patent Document 1 discloses an unburned ash classification system using a multi-cyclone. Because it uses a microcyclone, high flow velocities are generated locally, resulting in significant pressure loss, and because solid materials are centrifuged, the equipment wears down quickly, leading to high maintenance costs.

[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 separator, where the exhaust air is reversed by an arc-shaped surface. The ash, which swirls along the arc-shaped surface, is transferred to an ash duct and accumulated in an ash collection container that has no ventilation to the outside. The combustion air, from which the ash has been separated by the arc-shaped surface of the centrifugal separator, flows through an exhaust duct and is discharged outside the machine from the exhaust duct. The ash comes into contact with the arc-shaped surface of the centrifugal separator, resulting in severe wear.

[0004] Patent Document 3 discloses a white powder removal device. It discloses a collection plate for collecting white powder, and the collection plate is arranged so that its surface is perpendicular to the flow direction of the atmosphere flowing through the intake duct, or so that the collection plate is inclined upstream relative to the flow direction. In other words, the aim is to actively bring the white powder into contact with the collection plate, resulting in a large pressure loss between the upstream and downstream sides and severe wear.

[0005] Patent Document 4 discloses a flow straightening device for exhaust gas ducts. Multiple flow straightening plates are arranged concentrically with the curve in the exhaust gas duct through which exhaust gas discharged from a coal-fired boiler flows, and coal ash removal holes are drilled in the horizontal and nearly horizontal inclined portions of the flow straightening plates. The flow straightening plates are positioned at the point where the exhaust gas flow changes from vertical downwards to a horizontal direction, and coal ash is accumulated on the flow straightening plates.

[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 adjustable collection efficiency damper (obstruction plate) is provided so as to be movable up and down. The adjustable collection efficiency damper functions as an obstruction plate and is configured to actively bring unburned ash into the adjustable collection efficiency damper, resulting in significant wear. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Utility Model Publication No. 5-96735 [Patent Document 2] Patent No. 4082617 [Patent Document 3] Patent No. 6976381 [Patent Document 4] Japanese Patent Application Publication No. 08-075138 [Patent Document 5] Patent No. 3901453 [Patent Document 6] Patent No. 2898625 [Overview of the project] [Problems that the invention aims to solve]

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

[0010] Therefore, an object of the present disclosure is to provide a dust collecting device that can reduce pressure loss and wear of the device without using a conventional multicyclone.

Means for Solving the Problems

[0011] The dust collecting device (1) of the present disclosure is a gas introduction part (10; gas introduction region E) that introduces a gas flow (F1) containing a collection target (solid matter) in the gravity direction (from top to bottom), in ) and a gas inversion part (20) that inverts the gas flow (F1) introduced from the gas introduction part (10) in a direction opposite to the gravity direction (from bottom to top) and has two or more gas flow fractionation regions (E i ) along the flow direction of the inverted gas flow (along a direction not against the gas flow), a discharge part (30; collection object discharge region E) provided below the gas introduction part (10) and / or below the gas inversion part (20) that discharges the collection target downward, ex ) and is provided.

[0012] The gas introduction part (10) may have a rectangular cross-sectional shape in a plan view. When the gas introduction part (10) and the gas inversion part (20) are arranged side by side, they may have a substantially Y-shaped arrangement configuration in a front view. When the gas introduction part (10) and the gas inversion part (20) are arranged side by side, the shape in the depth direction may be rectangular in a front view. Similarly, the discharge part (3) may have a rectangular shape in the depth direction. The internal space cross-sectional area (rectangular cross-sectional area) of the gas introduction part (10) may be the same as or larger than the internal space cross-sectional area (rectangular cross-sectional area) of the discharge part (30).

[0013] The two or more gas flow fractionation regions (E i) A region where gas flows into or out of each other may be provided at the boundary of adjacent gas flow fractionation regions. For example, a through-hole may be formed in a plate-shaped louver, and the gas flow may pass through the through-hole. The two or more gas flow fractionation regions (E i ) may be configured by arranging one or more plate-shaped louvers (k j ), or by arranging hollow cylindrical bodies with a rectangular, circular, or polygonal cross-section. The two or more gas flow fractionation regions (E i ) may have the same or different sizes and gas flow angles. “j” ranges from 1 to n, and “i” ranges from 1 to n + 1.

[0014] When forming the two or more gas flow fractionation regions (E j ) with the plate-shaped louvers (k i ), each louver (k j ) may be arranged in parallel, and the interval (D i ) may be equally spaced or may vary at each stage. The length (L j ) of each louver (k j ) in the gas flow direction and the depth direction length (W j ) may be the same or different. The angle (α j ) of each louver (k j ) with respect to the horizontal may be the same or different. Each louver (k j ) may be parallel to the direction facing obliquely upward of the gas reversing portion (20).

[0015] The depth direction length (width) of the dust collecting device (1) should be at least as long as the length where the influence of wall friction on the gas flow does not occur. When increasing the device width (depth length), a structure (intermediate wall or support column) for supporting the louvers (k j ) etc. may be provided within the range that does not affect the gas flow according to the device strength.

[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, a 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 section (10b) that is inclined toward the gas reversal section (20), facing the gas reversal section (20). The inclined side wall portion (10b) may extend from an inclination start point (101a) that begins at the lower end of the vertical side wall portion (10a) to an inclination end point (101b) on the discharge portion (30) side. 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, smaller than 90° (vertical and uninclined).

[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 angles of less than 45° from the vertical. "Laterally from the first space (21)" may include the horizontal direction and the inclined direction 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 is connected 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 is preferably 40° or more and 80° or less. 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 is preferably between 40° and 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] Using the first imaginary line drawn from the upper connection start point (202a) to the lower connection start point (201a) as a reference, each of the louvers (k j One end of the ) may be positioned within the first space (21). Between the second virtual line drawn vertically downward from the upper connection starting point (202a) and the first virtual line, each of the louvers (k j ) may be placed there.

[0023] (effect) (1) As a solid, for example, fly ash with a large particle size containing a large amount of unburned material can be separated and recovered. (2) Compared to conventional technology (multi-cyclone), the pressure loss is very small, so the power required for the gas flow generating device (e.g., induced draft fan) can be reduced, and the operating costs of the equipment can be reduced. (3) Compared to conventional technology (multi-cyclone), the device structure is simpler, resulting in lower manufacturing costs. (4) Compared to conventional technology (multi-cyclone), the device structure is simpler, resulting in better maintainability and reduced maintenance costs. (5) Compared to conventional technology (multi-cyclone), the local flow velocity is lower, which reduces wear on the equipment, decreases the frequency of maintenance, and lowers maintenance costs. [Brief explanation of the drawing]

[0024] [Figure 1] This is a diagram showing the dust collection device of Embodiment 1. [Figure 2] This is a diagram showing the dust collection device of Embodiment 2. [Figure 3A] This figure shows an example of a louver in a different embodiment. [Figure 3B] This figure shows an example of a louver in a different embodiment. [Figure 3C] This figure shows an example of a louver in a different embodiment. [Figure 3D] This figure shows an example of a louver in a different embodiment. [Figure 3E] This figure shows an example of a louver in a different embodiment. [Figure 3F] This figure shows an example of a louver in a different embodiment. [Figure 4] This figure shows an example of a dust collection device according to another embodiment. [Figure 5] This figure shows an example of a dust collection device according to another embodiment. [Modes for carrying out the invention]

[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 unit 10 introduces a gas flow F1 containing the object to be collected (solid matter) in the direction of gravity. The gas flow F1 enters the gas introduction region E in the internal space. in In this configuration, the gas inlet section 10 has vertical side wall sections 10a and 10a' that extend vertically downward, and an inclined side wall section 10b that slopes toward the gas reversal section 20, with the side wall facing the gas reversal section 20 being vertical side wall sections 10a and 10a' that slopes toward the gas reversal section 20. The inclined side wall section 10b extends from a starting point 101a that begins at the lower end of the vertical side wall section 10a to a ending point 101b that ends toward the discharge section 30.

[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 unit 20 reverses the gas flow F1 introduced from the gas inlet unit 10 in the direction opposite to the direction of gravity, and creates two or more gas flow fractionation regions E along the flow direction of the reversed gas flow F1. i It has. Gas flow fractionation region E i This is a plate-shaped louver k j It is composed of arranging the following. Embodiment 1 has 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°. Also, the downward-sloping side wall 21a and the upward-sloping side wall 21b are arranged parallel to each other vertically. Furthermore, 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. In addition, each louver k is located between the first imaginary line drawn from the upper connection start point 202a to the lower connection start point 201a and the second imaginary line drawn vertically downward from the upper connection start point 202a. j These are arranged. Also, in a front view, the connecting 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 introduction section 10 and below the gas reversal section 20, and discharges the collected material downward. The discharge section 30 is located in the collected material discharge area E ex 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 introduction 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 ash is distributed in areas with larger particle sizes, while completely burned ash has smaller particle sizes. According to the dust collection device 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, and each louver k j Upon collision, the particle loses its velocity, and is then 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 proportion 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 proportion of ash material) flows to the gas reversal section 20. The particle recovery efficiency is determined by each louver k j gas flow fractionation region E demarcated by i It is influenced by the flow rate distribution of the gas flow F1 flowing through each gas flow fractionation region E. i It is believed that the closer the flow rate is to uniform, the better the recovery efficiency. Therefore, in this embodiment, each gas flow fractionation region E i Each louver k j They are arranged in parallel, and the spacing D is the same. Then, each louver k is formed by the inclined side wall portion 10b with an inclination angle β. j Considering the pressure loss when the gas is sent to the source, the gas flow F1 is rectified and sent downwards.

[0034] (Embodiment 2) The dust collector 1 of Embodiment 2, shown in Figure 2, differs from the dust collector 1 of Embodiment 1 in the configuration of the second space 22, while 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 another 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 partitioning regions. Depending on the cross-sectional area or volume of the first space 21, it can be set taking into account the effect of pressure loss in the gas flow F1. (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.

[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.

[0039] (6) Figure 3F shows the differences in the length of the louvers or gas flow fractionation regions. In Embodiment 1, the length L of each louver was the same. In Figure 3(b) on the right, the length L of each louver is configured to be different, and the length of the lower louver may be shorter. In Figure 3(a) on the left, the louver length L is shorter than that of Embodiment 1.

[0040] (7) In Figure 4(a), the gas inlet section 10 does not have an inclined side wall section 10b and extends to the discharge section 30. (8) In Figure 4(b), the gas inlet section 10 is generally inclined diagonally downward in a straight line. The gas inlet section 10 has a first inclined side wall section 10c that extends downward from the vertical, facing the gas reversal section 20, 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 inclination end point 101d, the angle θ2 from the horizontal to the second inclined side wall section 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. 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. In 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. [Explanation of Symbols]

[0042] 1. Dust collection device 10 Gas inlet 20 Gas reversal section 30 Discharge section

Claims

1. A gas inlet that introduces the gas flow containing the object to be collected in the direction of gravity, The gas flow introduced from the gas inlet is reversed in a direction opposite to the direction of gravity, and the gas reversal unit has two or more gas flow fractionation regions along the flow direction of the reversed gas flow, A discharge section is provided below the gas inlet and / or below the gas reversal section, and discharges the object to be collected downward, A dust collection device equipped with [a specific feature].

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

3. The aforementioned gas introduction section is The side wall facing the gas reversal section has a vertical side wall portion extending vertically downward and an inclined side wall portion inclined toward the gas reversal section. The dust collection device according to claim 1.

4. The aforementioned gas reversal section is A first space formed diagonally upward from the gas introduction section, It has a second space extending upward or laterally from the first space, The dust collection device according to claim 1.

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