An ejector-type fly ash separation device for the ash hopper of a power station boiler economizer

Abstract

The invention relates to the field of coal-fired steam boilers, and specifically to an induced-type fly ash separation device for an ash hopper of a power station boiler economizer, comprising a vertical flue, an ash hopper, a horizontal flue and an ascending flue connected in sequence, wherein an induced-type fly ash separation device is arranged in the vertical flue above the ash hopper, the induced-type fly ash separation device comprises a vertical flue, an ash hopper, a horizontal flue and a rising flue, wherein an induced-type fly ash separation device is arranged in the vertical flue above the ash hopper, the induced-type fly ash separation device comprises a plurality of spoiler brackets, a plurality of induced-type fly ash nozzles are provided at the bottom of each spoiler bracket, a one-way through groove is provided on the inner side of the spoiler bracket, the open end of the one-way channel is connected to an exhaust mechanism, and a first negative suction hole is formed in the spoiler bracket. The invention extracts part of the flue gas from the front flue, sends it into the induced-type fly ash separation device and ejects it, and drives the flue gas near the jet airflow to approach and collide with the ash hopper together by means of the negative pressure effect generated by the jet, so that the particles are more easily separated from the flue gas by wall collision with the spoiler bracket and collected, and the surrounding flue gas is continuously inhaled by the first negative suction hole and the second negative suction hole by means of the jet, thereby improving the fly ash collection efficiency.

Description

Technical Field

[0001] The invention relates to the field of coal-fired steam boilers, and in particular to an ejector-type fly ash separation device for an ash hopper of a power station boiler economizer. Background Art

[0002] Burning low-quality coal in W-shaped flame boilers effectively addresses energy supply challenges, but coal combustion also produces significant amounts of pollutants, such as NOx and fly ash dust. Selective catalytic reduction (SCR) denitrification systems are widely used in coal-fired power plants to reduce NOx emissions. Due to the required flue gas temperature for denitrification, SCR reactors are often located in the flue between the economizer and the air preheater. Flue gas in this flue carries a significant amount of fly ash particles. Large fly ash particles in the flue gas can cause wear on the SCR catalyst, catalyst clogging due to fly ash deposition, and catalytic poisoning caused by alkali metals in the fly ash, leading to significant degradation of SCR catalyst performance. The catalyst is the core of the SCR denitrification process, and degraded SCR catalyst performance can lead to reduced system denitrification efficiency and increased ammonia slip. Therefore, efficient ash removal, particularly the capture of large fly ash particles, before the flue gas enters the SCR denitrification reactor is crucial for preventing catalyst clogging and wear, and ultimately for the economical and safe operation of the entire boiler unit. Summary of the Invention

[0003] Based on this, it is necessary to provide an ejection type fly ash separation device for the ash hopper of the economizer of a power station boiler in response to the existing technical problems.

[0004] In order to solve the problems of the prior art, the technical solution adopted by the present invention is:

[0005] An ejector-type fly ash separation device for a power station boiler economizer ash hopper, which is arranged between the economizer and the air preheater, comprises:

[0006] The flue body is composed of a vertical flue, a horizontal flue and an ascending flue connected in sequence, with the two ends of the horizontal flue connected to the lower ends of the vertical flue and the ascending flue respectively;

[0007] An ash hopper is located at the lower end of the vertical flue and is set lower than the horizontal flue;

[0008] An ejection mechanism is provided in the vertical flue above the ash hopper, the ejection mechanism being composed of a plurality of spoiler brackets arranged linearly and equidistantly, the arrangement direction of all the spoiler brackets being perpendicular to the flue gas flow direction, a plurality of ejection nozzles distributed at equal intervals being provided at the bottom of each of the spoiler brackets, the jet direction of the ejection nozzles being arranged obliquely downward toward the horizontal flue, a one-way groove being provided on the inner side of the spoiler bracket, the groove being in the same direction as its own length direction and intersecting with the upper ends of all the ejection nozzles within its length coverage range, the open end of the one-way groove being connected to an exhaust mechanism, the exhaust mechanism being used to extract a portion of the flue gas from the economizer into the one-way groove and eject it from the ejection nozzle;

[0009] Among them, the spoiler bracket is also formed with first negative suction holes of the same number as the injection nozzle. The lower end of each first negative suction hole is connected to the upper end of the corresponding injection nozzle, and the upper end of the first negative suction hole is connected to the space above the spoiler bracket. The first negative suction hole is connected to the corresponding injection nozzle in a "Y" shape.

[0010] Preferably, the jet direction of the ejector nozzle is set at an angle of 45° to the horizontal plane, and the ejector nozzle is facing the inner wall of the ash hopper. The cross-section of the spoiler bracket is a right triangle, and the inclined surface of the spoiler bracket is set towards the vertical flue.

[0011] Preferably, a collecting extension tube is provided at the lower end of each of the ejection nozzles, and the length direction of the collecting extension tube is consistent with the jet direction of the ejection nozzle.

[0012] Preferably, a Tesla one-way valve structure is provided on the inner side of the collecting extension pipe, and the air outlet of the Tesla one-way valve structure is arranged toward the ash hopper.

[0013] Preferably, a plurality of second negative suction holes communicating with the outside are respectively provided on both side walls of the Tesla one-way valve structure.

[0014] Preferably, a number of guide plates for dispersing the smoke are evenly spaced on the inner side of the top entrance of the vertical flue, and a number of groups of airflow dispersion mechanisms are provided in the horizontal flue and the ascending flue, and each group of airflow dispersion mechanisms is composed of a number of guide plates evenly spaced and dispersed in the flue.

[0015] Preferably, the guide blade has a V-shaped louver structure, and its tip faces the direction of smoke flow.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] Firstly, the present invention reduces the kinetic energy of the ash-containing flue gas and, by virtue of the centrifugal force and gravity of the particles, makes it easier for the particles to collide with the wall of the spoiler bracket, thereby being separated from the flue gas and collected;

[0018] Secondly, the present invention provides an ejector mechanism at the bend of the flue above the ash hopper. The ejector mechanism tilts downward to cause the ash-containing flue gas to collide with the inner wall of the ash hopper, thereby improving the fly ash collection efficiency.

[0019] Thirdly, the present invention extracts part of the flue gas from the front flue and sends it into the ejector mechanism for ejection. At the same time, the negative pressure effect generated by the jet flow drives the flue gas near the jet flow to collide with the ash hopper, further improving the fly ash collection efficiency.

[0020] Fourthly, the present invention uses the first negative suction hole on the top of the spoiler bracket and the second negative suction hole on the side wall of the collection extension tube to continuously inhale the surrounding smoke with the help of the jet, thereby further improving the fly ash collection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the planar structure of the present invention;

[0022] Figure 2 is a schematic cross-sectional view of the spoiler bracket located at the jet nozzle and the first negative suction hole;

[0023] Figure 3 yes Figure 2 The plane section view along line AA;

[0024] Figure 4 It is a planar cross-sectional view of the radiation extension tube;

[0025] Figure 5 This is a planar schematic diagram of the coordination principle between the Tesla one-way valve structure and the second negative suction hole;

[0026] The numbers in the figure are: 1-vertical flue; 2-horizontal flue; 3-ascending flue; 4-ash hopper; 5-spoiler bracket; 6-injection nozzle; 7-one-way groove; 8-guide plate; 9-first negative suction hole; 10-collecting extension pipe; 11-Tesla one-way valve structure; 12-second negative suction hole; 13-guide leaf; 14-air flow dispersion mechanism. DETAILED DESCRIPTION

[0027] In order to further understand the features, technical means, specific objectives and functions achieved by the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Reference Figures 1 to 5 As shown, an ejector-type fly ash separation device for the ash hopper of a power station boiler economizer is provided between the economizer and the air preheater, comprising:

[0029] The flue body is composed of a vertical flue 1, a horizontal flue 2 and an ascending flue 3 connected in sequence, with the two ends of the horizontal flue 2 connected to the lower ends of the vertical flue 1 and the ascending flue 3 respectively;

[0030] The ash hopper 4 is located at the lower end of the vertical flue 1 and is arranged below the horizontal flue 2;

[0031] An ejection mechanism is provided in the vertical flue 1 above the ash hopper 4. The ejection mechanism is composed of a number of linearly and equidistantly arranged spoiler brackets 5. The arrangement direction of all the spoiler brackets 5 is perpendicular to the flow direction of the flue gas. A number of equally spaced ejection nozzles 6 are provided at the bottom of each spoiler bracket 5. The jet direction of the ejection nozzles 6 is inclined downward toward the horizontal flue 2. A one-way groove 7 is provided on the inner side of the spoiler bracket 5, which is in the same direction as its own length direction and intersects with the upper ends of all the ejection nozzles 6 within its length coverage. The open end of the one-way groove 7 is connected to an exhaust mechanism, which is used to extract a portion of the flue gas from the economizer into the one-way groove 7 and eject it from the ejection nozzle 6.

[0032] Among them, the spoiler bracket 5 is also formed with the same number of first negative suction holes 9 as the injection nozzle 6. The lower end of each first negative suction hole 9 is connected to the upper end of the corresponding injection nozzle 6, and the upper end of the first negative suction hole 9 is connected to the space above the spoiler bracket 5. The first negative suction hole 9 is connected to the corresponding injection nozzle 6 in a "Y" shape.

[0033] The jet direction of the ejector nozzle 6 is set at an angle of 45° to the horizontal plane, and the ejector nozzle 6 is facing the inner wall of the ash hopper 4. The cross-section of the spoiler bracket 5 is a right triangle, and the inclined surface of the spoiler bracket 5 is set toward the vertical flue 1. After the flue gas enters the vertical flue 1, it hits the inclined surface of the spoiler bracket 5, which greatly reduces the kinetic energy of the flue gas.

[0034] When the flue gas containing particles enters the horizontal flue 2 from the top of the vertical pipe and turns downward, the particles in the flue gas will be separated due to the action of centrifugal force and gravity, so that some particles enter the ash hopper 4 and are collected by the ash hopper 4. At the same time, when the flue gas flows through the spoiler brackets 5 evenly distributed above the ash hopper 4, it collides with the wall surface of the spoiler bracket 5, further causing the movement direction of the particles to change and the kinetic energy to decrease, so that the particles are more likely to enter the ash hopper 4 and be collected, effectively improving the fly ash capture rate;

[0035] In order to further improve the fly ash collection effect, a number of jet nozzles opened on the bottom surface of each spoiler bracket 5 spray jets at a 45° angle downward toward the inner wall of the ash hopper 4. On the one hand, the flue gas containing particles is blown toward and hits the inner wall of the ash hopper 4, so that the particles are intercepted in the ash hopper 4 and collected. On the other hand, after the jet flows through the area below the spoiler bracket 5, a negative pressure area is formed around the jet path, so that the flue gas scattered around is sucked into the jet path under the action of the negative pressure, so that this part of the flue gas is also ejected toward the inner wall of the ash hopper 4 for collection, thereby further improving the fly ash particle collection efficiency.

[0036] In order to speed up and further improve the fly ash collection effect, a first negative suction hole 9 is provided on one side of each ejection nozzle 6 in a "Y"-shaped distribution therewith, and the first negative suction hole 9 is connected to the space above the spoiler bracket 5. In the process of the exhaust mechanism extracting part of the flue gas in the front flue and sending it into all the ejection nozzles 6 through the one-way groove 7 for downward ejection, the high-pressure airflow will take away the air in the first negative suction hole 9, thereby generating a negative pressure in the first negative suction hole 9, and then the flue gas in the space above the spoiler bracket 5 is caused to enter from the first negative suction hole 9 and from the one-way groove 7 through the jet nozzle together to be collected on the inner wall of the ash hopper 4, thereby further improving the collection efficiency of the fly ash particles.

[0037] In order not to waste the energy of the exhaust mechanism, the inlet of the exhaust mechanism is connected to the flue in front of the device through a pipe, and part of the flue gas coming out of the economizer is extracted and sent into the spoiler bracket 5. Compared with directly extracting air from the outside for jetting, this method can further improve efficiency by directly extracting flue gas.

[0038] A collecting extension tube 10 is installed at the lower end of each ejection nozzle 6. The length of the collecting extension tube 10 is aligned with the jet direction of the ejection nozzle 6. To further increase the velocity of the airflow ejected from the ejection nozzle 6 and improve the fly ash impaction effect, a collecting extension tube 10 for pressurization is installed at the outlet of the ejection nozzle 6. The cross-sectional area of ​​the through hole of the collecting extension tube 10 is gradually narrowed, thereby increasing the velocity and pressure of the flue gas exiting the small opening, and the flue gas ejection effect after passing through the collecting extension tube 10 is improved.

[0039] A Tesla one-way valve structure 11 is provided on the inner side of the collecting and ejecting extension pipe 10, and the gas outlet of the Tesla one-way valve structure 11 is arranged toward the ash hopper 4. The collecting and ejecting extension pipe 10 can adopt the Tesla one-way valve structure 11. After the flue gas enters the Tesla one-way valve structure 11 from the ejection nozzle 6 and is pressurized and accelerated, it is rapidly ejected and ejected toward the wall of the ash hopper 4. While the Tesla one-way valve structure 11 accelerates the ejection of the flue gas from the ejection nozzle 6, it further strengthens the negative pressure suction effect of the first negative suction hole 9, thereby strengthening the absorption effect of the flue gas in the space above the spoiler bracket 5. This process has a double effect of improving the fly ash capture rate.

[0040] A plurality of second negative suction holes 12 communicating with the outside are respectively provided on the two side walls of the Tesla one-way valve structure 11. In order to further accelerate the absorption efficiency of the flue gas floating in the space below the spoiler bracket 5, a plurality of second negative suction holes 12 are provided on both sides of the Tesla one-way valve structure 11. When the flue gas passes through the Tesla one-way valve structure 11 at high speed, negative pressure is also generated in the second negative suction holes 12, thereby causing the flue gas in the surrounding environment to be sucked into the Tesla one-way valve structure 11. This portion of the flue gas is then combined with the main flue gas passing through the Tesla one-way valve structure 11 to form a stream of air that is jointly emitted toward the inner wall of the ash hopper 4. The second negative suction holes 12 enhance the absorption effect of the flue gas floating in the space below the spoiler bracket 5.

[0041] A plurality of guide blades 13 for dispersing the flue gas are evenly spaced on the inner side of the top entrance of the vertical flue 1. The horizontal flue 2 and the ascending flue 3 are both provided with a plurality of groups of airflow dispersion mechanisms 14. Each group of airflow dispersion mechanisms 14 is composed of a plurality of guide plates 8 evenly spaced and dispersed in the flue. The guide blades 13 are in a V-shaped louver structure, and their tips face the direction of flue gas flow. The guide blades 13 are used to evenly disperse the flue gas entering the vertical flue 1 in the flue, thereby reducing the kinetic energy of the incoming flue gas to facilitate the subsequent fly ash collection process. The horizontal flue 2 and the ascending flue 3 are segmented and provided with a plurality of guide plates 8 at intervals, so that the flue gas can pass through in an evenly dispersed state. The spacing of the airflow channels between the guide plates 8 can be changed by changing the V angle of the guide plates 8, thereby adjusting different flue gas entry flow rates.

[0042] The above embodiments merely represent one or several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. An ejector-type fly ash separation device for a power station boiler economizer ash hopper, which is arranged between the economizer and the air preheater, characterized in that: include: A flue body, the flue body consisting of a vertical flue (1), a horizontal flue (2) and an ascending flue (3) connected in sequence, with both ends of the horizontal flue (2) being connected to the lower ends of the vertical flue (1) and the ascending flue (3) respectively; An ash hopper (4) is located at the lower end of the vertical flue (1) and is arranged below the horizontal flue (2); An ejection mechanism is provided in a vertical flue (1) above an ash hopper (4), the ejection mechanism being composed of a plurality of linearly equidistantly arranged spoiler brackets (5), the arrangement direction of all the spoiler brackets (5) being perpendicular to the flue gas flow direction, a plurality of equally spaced ejection nozzles (6) being provided at the bottom of each spoiler bracket (5), the jet direction of the ejection nozzles (6) being inclined downward in the direction of the horizontal flue (2), a one-way slot (7) being provided on the inner side of the spoiler bracket (5) being in the same direction as its own length direction and intersecting with the upper ends of all the ejection nozzles (6) within its length coverage, the open end of the one-way slot (7) being connected to an exhaust mechanism, the exhaust mechanism being used to extract a portion of the flue gas from the economizer to the one-way slot (7) and eject the gas from the ejection nozzles (6); The spoiler bracket (5) is further formed with first negative suction holes (9) of the same number as the ejection nozzle (6), the lower end of each first negative suction hole (9) is connected to the upper end of the corresponding ejection nozzle (6), the upper end of the first negative suction hole (9) is connected to the upper space of the spoiler bracket (5), and the first negative suction hole (9) is connected to the corresponding ejection nozzle (6) in a "Y" shape.

2. The ejection type fly ash separation device for the ash hopper of a power station boiler economizer according to claim 1, characterized in that: The jet direction of the ejection nozzle (6) is set at an angle of 45 degrees to the horizontal plane, and the ejection nozzle (6) is directly opposite the inner wall of the ash hopper (4). The cross section of the spoiler bracket (5) is a right triangle, and the inclined surface of the spoiler bracket (5) is set toward the vertical flue (1).

3. The ejection type fly ash separation device for the ash hopper of a power station boiler economizer according to claim 1, characterized in that: A collection extension tube (10) is provided at the lower end of each of the ejection nozzles (6), and the length direction of the collection extension tube (10) is consistent with the jet direction of the ejection nozzle (6).

4. The ejector-type fly ash separation device for the ash hopper of a power station boiler economizer according to claim 3, characterized in that: A Tesla one-way valve structure (11) is provided on the inner side of the collecting extension pipe (10), and the gas outlet of the Tesla one-way valve structure (11) is arranged toward the ash hopper (4).

5. The ejection type fly ash separation device for the ash hopper of a power station boiler economizer according to claim 4, characterized in that: A plurality of second negative suction holes (12) communicating with the outside are respectively provided on both side walls of the Tesla one-way valve structure (11).

6. The ejection type fly ash separation device for the ash hopper of a power station boiler economizer according to claim 1, characterized in that: A plurality of guide plates (13) for dispersing smoke are arranged at equal intervals on the inner side of the top entrance of the vertical flue (1), and a plurality of groups of airflow dispersing mechanisms (14) are arranged in the horizontal flue (2) and the ascending flue (3), and each group of airflow dispersing mechanisms (14) is composed of a plurality of guide plates (8) dispersedly arranged at equal intervals in the flue.

7. The ejection type fly ash separation device for the ash hopper of a power station boiler economizer according to claim 6, characterized in that: The guide blade (13) has a V-shaped louver structure, and its tip faces the direction of smoke flow.

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