Anti-secondary dust type plate

Abstract

The invention relates to an anti-secondary dust-raising type electrode plate for an electrostatic precipitator, which is characterized by: 3D structure, multi-layer coupling, constructing a channel with multiple turns for dust-containing airflow and one, two or three "safe havens" for dust to fall. Since the "safe havens" isolate the airflow, the dust is not affected by wind force in the process of falling in the "safe havens". Under the action of electric field force, the dust is charged and adheres to the inclined surface of the louver stem. The dust collected by the louver stem is continuously affected by the continuous electric field force, and the dust bouncing on the inclined surface of the louver stem due to the vibration force is pushed into the "safe haven" and poured down under the action of gravity. The electric lines form a "golden bell" on the outer surface of the louver to inhibit the dust in the "safe haven" from overflowing, so the electrode plate will not generate secondary dust when vibrated; since the dust collecting surface is a discontinuous metal structure of intermittent louvers, no large pieces of dust cakes will be formed, and no charge accumulation will be formed for high or low resistivity dust, which can effectively avoid the occurrence of back corona.

Description

Technical Field

[0001] The invention relates to the technical field of flue gas dust removal, in particular to an anti-secondary dust type plate for an electric precipitator. Background Art

[0002] Electrostatic precipitator is still the mainstream equipment for purifying large volume of smoke from industrial furnaces. Now, it has become a cost-effective technical route to utilize the internal space of the known electric field to superimpose other dust removal equipment and upgrade the known functional parts of the known electrostatic precipitator to improve its efficiency.

[0003] The known technical routes for improving the efficiency of electrostatic precipitators include: flue gas conditioning, electric bags, cloth bags, power supply modification, increasing the number of electric fields, raising and widening the electric field, and modifying the end electric field to a rotating pole plate for dust-free cleaning. These measures all have problems of one kind or another, and no substantial solution has been found to the problems.

[0004] The known selection calculation of electrostatic precipitator can solve the problem of dust collecting area, but cannot solve the problem of secondary dust. Secondary dust is an important factor affecting the efficiency of electrostatic precipitator. If the dust in the electrostatic precipitator is charged and captured, and is vibrated and peeled off without flying, the number, weight and investment of electric fields can be reduced. If the dust that is turbid due to vibration or back corona is not repeatedly charged, the energy consumption can be greatly reduced.

[0005] One of the problems of poor performance of currently known electrostatic precipitators is essentially caused by the anode plate structure. Although the currently known various forms of anode plates are also designed with windproof grooves with a height of no more than 50mm, the inhibitory effect on secondary dust is limited; the rotating pole plate has the function of overcoming secondary dust without dust brushing, but the rotating pole plate has a complex structure, there are many rotating parts in the dust, and the system failure rate is high. There are many cases in China where the rotating pole plates have been dismantled to restore the known electric field.

[0006] The present invention is aimed at the plate dust stress model (see attached Figure 1 ) analysis, it is concluded that the key force leading to secondary dust is the wind force of the smoke flow. If a "safe haven" is set for the falling dust, and the wind force of the smoke flow in the "safe haven" is zero, then secondary dust can be effectively suppressed or even avoided.

[0007] Based on this idea, the inventor studied and tested the "safe haven" structure created by dust falling, and the dust stress model on the dust collecting plate for preventing secondary dust emission is shown in Figure 2 , and have achieved relatively good application results after being tested in engineering practice. Summary of the invention

[0008] The arrangement of the device of the present invention is divided into two types: parallel airflow arrangement and vertical airflow arrangement. The structure is divided into four series: single-channel (mouth-shaped) transparent type, double-channel (sun-shaped) transparent type, double-channel non-transparent type, and three-channel (eye-shaped) transparent type.

[0009] The secondary dust prevention device arranged in vertical airflow is divided into cathode and anode in terms of polarity. The polarity of parallel airflow arrangement is anode. All structural types can be used as anode for parallel airflow. The vertical airflow arrangement can only be a transparent device.

[0010] The unit body of the device is a metal plate with 3D louver holes. The holes are diamond-shaped or hexagonal. The holes are connected by stems with a certain width and inclination angle. The two layers of louvered metal plates are relatively coupled to form a box shape. The airflow blows through the outside of the box, and there is no horizontal flow of smoke in the inner cavity of the box, thus creating a "safe haven" for the falling dust.

[0011] Although the plates arranged in parallel airflow and those arranged in vertical airflow are similar in structure, their dust removal methods are different.

[0012] For the anode device with parallel airflow arrangement, the dust is gathered on the inclined stems of the 3D louver metal plate under the action of the electric field force (see Figure 3 ), under the action of the vibration force, when the dust bounces on the louver stem, the dust is pushed into the "safe haven" along the inclined surface of the stem under the action of the electric field force and ion wind, and the dust pours down from the "safe haven" to form a "gray waterfall". At the same time, the charged dust in the subsequent flue gas rushes to the surface of the 3D louver metal plate. The "golden bell" formed by the power lines suppresses the dust falling in the "safe haven" from overflowing under the action of turbulence, thereby avoiding the secondary flying of dust on the surface of the plate after vibration. The vivid metaphor is: a group of people gather together and sit on a slide to bungee jump (see Figure 4 ), belongs to active dust collection, and the invented device can replace the known electrode plates.

[0013] For the secondary dust prevention type plate arranged vertically in the airflow, its suppression effect on secondary dust mainly depends on the centrifugal effect of airflow speed change, the collision and condensation of the changing direction, and the blocking of the dust by the staggered holes when it falls (see Figure 5 ), to achieve the purpose of collecting secondary dust with residual charge escaping from the electric field. The quality of the electric field function and the amount of charge of the escaping dust are key factors affecting the dust removal efficiency. The anti-secondary dust type plate arranged in vertical airflow belongs to passive dust collection, which is a supplementary transformation method to improve the efficiency of the known electric field.

[0014] The application fields of the anti-secondary dust type electrode plate involved in the present invention include mechanical dust collectors, dry electrostatic precipitators, and wet electrostatic precipitators. It can be used as dust collecting electrode parts for new construction projects, and is particularly suitable for improving the efficiency or upgrading and replacing existing inefficient equipment. The renovation project volume is small, the implementation cycle is short, and there is basically no additional maintenance workload. It is more energy-saving and does not increase system resistance. Compared with other renovation processes, it has a higher cost-effectiveness.

[0015] Compared with the known perforated mesh and woven wire mesh dust collecting devices, the device of the present invention has a different dust collecting mechanism and a different dust collecting area in the same spatial arrangement. The vibration acceleration transmission performance of the device of the present invention is better and the dust cleaning is more thorough. The dust removal efficiency of the present invention is superior.

[0016] The beneficial effects of the present invention are as follows: simple and novel structure, easy for mass production, convenient for handling and transportation, conducive to on-site installation, small occupation of space, large dust collecting surface area, and its surface area is several times the dust collecting area of ​​the known electric field, which can improve the overall electrostatic dust removal efficiency, and provide a cost-effective product and technical route for the efficiency improvement and transformation of the known electrostatic precipitator, which can be used for newly built electrostatic precipitator equipment to optimize the number of known electric fields and achieve the goal of ultra-low dust emissions in one step. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a known model of the forces acting on dust particles on the electrode plate.

[0018] Figure 2 Force model of dust on the device of the present invention.

[0019] Figure 3 A working principle diagram of the anti-secondary dust type plate dust capture in the parallel airflow arrangement of the device of the present invention.

[0020] Figure 4 A working principle diagram of dust-free cleaning of the anti-secondary dust type plate in the parallel airflow arrangement of the device of the present invention.

[0021] Figure 5 A working principle diagram of the secondary dust prevention type pole plate arranged in a vertical airflow arrangement of the device of the present invention.

[0022] Figure 6 A schematic plan view of the 3D louver metal plate of the present invention.

[0023] Figure 7 A two-dimensional schematic diagram of the 3D louver metal plate facade according to the present invention.

[0024] Figure 8 A three-dimensional schematic diagram of the 3D louver metal plate facade according to the present invention.

[0025] Fig. 9 A three-dimensional view of a single-channel (U-shaped) transparent device module in Example 1.

[0026] Fig.10 Schematic cross-sectional view of the dual-channel (H-shaped) transparent device in Example 2.

[0027] Fig.11 Schematic cross-sectional view of the dual-channel (H-shaped) non-transparent device in Example 3.

[0028] Fig.12 Schematic three-dimensional structure view of the dual-channel (H-shaped) non-transparent device in Example 3.

[0029] Fig.13 Schematic two-dimensional cross-sectional structure view of the triple-channel (eye-shaped) transparent device in Example 4.

[0030] Fig.14 Schematic three-dimensional view of the triple-channel (eye-shaped) transparent device in Example 4. Detailed implementation manners

[0031] Figure 1 Among them: The electric field force shown by F1, that is, the force for dust to adhere to the electrode plate. Affected by the power supply situation, especially during electric field flashover, the electric field force fluctuates greatly. In case of back corona, the direction of the electric field force F1 is reversed and is consistent with the rapping force F2, and the dust becomes the "popcorn" on the electrode plate, accelerating the dust to escape from the electrode plate, and the secondary dust emission is aggravated.

[0032] Figure 1 Among them: The rapping force shown by F2, that is, the force to strip the dust from the electrode plate. Once the parameters such as the weight of the rapping hammer and the radius of gyration (or stroke) are determined, this force is a constant.

[0033] Figure 1 Among them: The gravity shown by F3. The gravity of a single dust particle can be almost ignored, but when the dust agglomerates and condenses into clusters, flakes, blocks, or cakes, it has weight. The self-weight of the falling dust, the force moving from top to bottom is related to the particle size, volume, and density of the dust.

[0034] Figure 1 Among them: The wind force (or drag force) shown by F4 is the force generated by the gas flow from front to back inside the electric field, and the wind force varies with the load fluctuation of the unit.

[0035] Figure 1 Among them: For a single dust particle, F1, F2, F3, and F4 finally synthesize a resultant force downward and backward. Some dust can reach the ash hopper, while some dust drifts to the subsequent electric field or escapes. The escaping dust is the secondary dust emission.

[0036] Figure 2 Among them: For the anti-secondary-dust-emission type electrode plate arranged with parallel air flow, the dust particles agglomerate on the 3D louver inclined ribs, and the force acting on them is the same as that of Figure 1The force model of the dust particles on the plate is different. At this time, the airflow cannot enter the dust falling channel "safe haven", and the dust is not affected by the wind force F4. At this time, F4 is zero. Under the action of the electric field force, the dust is captured by the 3D shutter oblique stems (see Figure 3 ), when the device is vibrated and cleaned, it slides down from the inclined stem surface into the "safe haven" and jumps down, achieving dust-free cleaning (see Figure 4 ) and enters the ash hopper, so no secondary dust will be generated.

[0037] Figure 5 Middle: For the secondary dust prevention device arranged in vertical airflow, dust particles gather on the 3D louver stalk (02), and the force on it is similar to Figure 1 The force model of the dust particles on the plate is basically the same. At this time, the airflow passes horizontally into the dust falling channel "safe haven". When the dust-containing airflow passes through the 3D structural hole (03) to accelerate and turn (micro-cyclone gas-solid separation principle), the dust is retained on the 3D louver slant stem (02) due to the dust mass and viscosity as well as the residual charge. When the flue gas passes through the ash falling channel "safe haven" in a "V"-shaped trajectory, it will first accelerate and then decelerate, creating conditions for the dust that has been agglomerated and grown to fall. When the plate is cleaned by the vibration force F2, it slides from the surface of the 3D louver slant stem (02) into the ash falling channel "safe haven" and jumps down, rushing into the ash collecting hopper like a "ash waterfall". The anti-secondary dust type plate arranged in the vertical airflow adopts the method of shutting off the corresponding local airflow when it is locally vibrated (offline cleaning technology), which can also prevent the generation of secondary dust.

[0038] Figure 5 Middle: 3D louver metal plates (0) are generally arranged in 2 to 4 layers, and the holes (03) are arranged in a staggered manner. The vertical downward gravity F3 on the agglomerated and grown dust is greater than the horizontal wind force F4, so that the dust can fall faster under the turbulent effect in the "safe haven" of the dust falling channel.

[0039] Figure 6 , Figure 7 and Figure 8 They are respectively a two-dimensional main view, a two-dimensional side view and a three-dimensional side view of the structural unit of the dust collection function module 3D louver metal plate (0). The 3D louver metal plate (0) includes: an edge (01), a stem (02), and a hole (03). The embodiments all use the 3D louver metal plate (0) as a basic element and are composed of different numbers or different forms of skeleton carriers.

[0040] Each of the 3D louvered metal plates (0) is provided with through holes (03). On one side of each through hole (03), a louver rib (02) is evenly provided, and the louver ribs (02) are symmetrically distributed at intervals on the 3D louvered metal plate (0), thus forming the 3D louvered metal plate (0). The through holes (03) are 3D square or diamond-shaped, and all the through holes (03) are provided with louver ribs (02) inclined in the same direction. When installed, the inclination direction of the louver ribs (02) is the direction of the oncoming air flow. The mesh number of each 3D louvered metal plate (0) is 50 - 200 meshes, and its opening ratio is greater than 40% and less than 60%.

[0041] Fig. 9 Fig. is the three-dimensional view of the single-channel (square-shaped) permeable device module (1) in Embodiment 1. In the figure: The single-channel (square-shaped) permeable device module (1) includes a front 3D louvered metal plate (1-01), a reverse 3D louvered metal plate (1-02), an inner skeleton (1-1), an outer skeleton (1-2), fasteners (1-3). The U-shaped vertical edges of the front and reverse 3D louvers are clamped between the inner and outer skeletons (1-1) and (1-2), and the three parts are combined into the structural form of the single-channel (square-shaped) permeable device module (1) with fasteners (1-3).

[0042] Fig.10 Fig. shows the double-channel (H-shaped) permeable device (2-1) in Embodiment 2, which is composed of a front diaphragm (2-10), a reverse diaphragm (2-11), a front windbreak (2-12), and a reverse windbreak (2-13). This device can be arranged perpendicular to the air flow or parallel to the air flow.

[0043] Fig.11 and Fig.12 Fig. shows the two-dimensional cross-section and three-dimensional cross-section of the double-channel (H-shaped) non-permeable device in Embodiment 3. The double-channel (H-shaped) non-permeable device is composed of a single-channel (square-shaped) permeable device module (1), a front windbreak (2-12), a reverse windbreak (2-13), and a well-known anode plate (2-2). This device can only be arranged parallel to the air flow and cannot be arranged perpendicular to the air flow.

[0044] The beneficial effect of Embodiment 3 is to transform the known anode plate. Using the known anode plate as a framework, a 3D louvered metal plate (0) is coupled to each side of the known anode plate. The angle of the louver stems (02) inclines towards the "safe havens (3-01), (3-02), (3-03)". Under the action of the electric field force, the charged dust adheres to the inclined surfaces of the louver stems (02). Under the action of the rapping force, the dust slides along the inclined surfaces of the louver stems (02) towards the "safe havens (3-01), (3-02), (3-03)" formed by the electrode plate and the louvers. The ash pours down from the "safe havens (3-01), (3-02), (3-03)". Since the "safe havens (3-01), (3-02), (3-03)" isolate the air flow, the ash is not affected by the wind force during the falling process in the "safe havens (3-01), (3-02), (3-03)". The dust collected on the outer surface of the louver stems (02) that play the dust collection role is continuously affected by the electric field force, pushing the dust towards the ash-falling "safe havens (3-01), (3-02), (3-03)", and at the same time suppressing the overflow of dust in the "safe havens (3-01), (3-02), (3-03)". Therefore, no secondary dust generation will occur when the electrode plate is vibrated. Since the dust collection surface is a discontinuous louver non-continuous metal structure, no large ash cakes will be formed. For high or low specific resistance dust, no charge accumulation will occur, effectively avoiding back corona, achieving the one-way flow of dust, thereby reducing the dust emission concentration and improving the dust removal efficiency of the electrostatic precipitator.

[0045] Fig.13 and Fig.14 Figures 2D and 3D of the three-channel (eye-shaped) permeable device of Embodiment 4. The three-channel (eye-shaped) permeable device is constructed by two single-channel (square-shaped) permeable devices (1) and a connecting piece (3-1) to form three "safe havens (3-01), (3-02), (3-03)" for dust to fall. This embodiment can be arranged perpendicular to the air flow or parallel to the air flow and can be used as the cathode or anode of an electrostatic precipitator.

[0046] The invention is not limited to the above embodiments. Other structural designs obtained by adopting structures that are the same as or similar to the above design concept and implementation method examples of the present invention are all within the protection scope of the present invention.

Claims

1. An anti-secondary dust type plate for an electrostatic precipitator, characterized in that: It is composed of 3D louvered metal plates (0) as basic components, combined with different numbers or different forms of skeleton carriers; the 3D louvered metal plates (0) include: edges (01), louver ribs (02), and through holes (03). One louver rib (02) is evenly provided on one side of each through hole (03), and the louver ribs (02) are symmetrically distributed at intervals on the 3D louvered metal plates (0). The through holes (03) are 3D square or diamond-shaped, and all the through holes (03) are provided with louver ribs (02) inclined in the same direction. When installed, the inclination direction of the louver ribs (02) is the direction of the oncoming air flow and is inclined towards the direction of the gravity of the dust. Two layers of the 3D louvered metal plates (0) are coupled relatively to form a box shape, creating a safe haven for the falling dust.

2. The anti-secondary dust type electrode plate for an electrostatic precipitator according to claim 1, characterized in that: The mesh number of each 3D louvered metal plate (0) is 50 - 200 meshes, and its opening rate is greater than 40% and less than 60%.

3. The anti-secondary dust type electrode plate for an electrostatic precipitator according to claim 1, characterized in that: The single-channel mouth-shaped permeable device module (1) includes a positive 3D louvered metal plate (1-01), a negative 3D louvered metal plate (1-02), an inner skeleton (1-1), an outer skeleton (1-2), and fasteners (1-3). The U-shaped vertical edges of the positive and negative 3D louvers are clamped between the inner skeleton (1-1) and the outer skeleton (1-2), and the three parts are combined into the structural form of the single-channel mouth-shaped permeable device module (1) with fasteners (1-3).

4. The anti-secondary dust type electrode plate for an electrostatic precipitator according to claim 1, characterized in that: The double-channel day-shaped permeable device (2-1) is composed of a positive diaphragm (2-10), a negative diaphragm (2-11), a positive safe haven (2-12), and a negative safe haven (2-13). This device is arranged for vertical air flow or parallel air flow.

5. The anti-secondary dust type electrode plate for an electrostatic precipitator according to claim 1, characterized in that: The double-channel day-shaped non-permeable device is composed of a single-channel mouth-shaped permeable device module (1), a positive safe haven (2-12), a negative safe haven (2-13), and a well-known anode plate (2-2). This device can only be arranged for parallel air flow and cannot be arranged for vertical air flow.

6. The anti-secondary dust type electrode plate for an electrostatic precipitator according to claim 1, characterized in that: The three-channel mesh-shaped permeable device is constructed by two single-channel mouth-shaped permeable device modules (1) and a connector (3-1) to create three safe havens (3-01), (3-02), and (3-03) for the falling dust. This device is arranged for vertical air flow or parallel air flow and is used as the cathode or anode of an electrostatic precipitator.

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