CN202700653U - Discharge electrode of electrostatic precipitator - Google Patents

Abstract

The utility model discloses a discharge electrode of an electric precipitator, which comprises at least one discharge electrode trunk and at least one saw tooth distributed on the side of the discharge electrode trunk. Make the sawtooth of the discharge tip form a certain angle with the main plane of the discharge electrode, thereby increasing the current density and the uniformity of distribution. At the same time, the mechanical strength and economical efficiency of the discharge electrode are significantly improved, and the corona inception voltage is effectively reduced. The utility model can be used in the discharge structures of various electric precipitators and electric demisters, and can control pollutants such as water mist, smoke dust, sulfur trioxide aerosol and the like in the flue gas of various coal-fired boilers or incinerators.

Description

A discharge electrode of an electric precipitator

technical field

The utility model belongs to the technical field of environmental protection and waste gas purification, in particular to a discharge electrode for an electric dust collector.

Background technique

The flue gas contains a large amount of smoke and aerosol (water mist, acid mist, escaped ammonia, etc.), and the most commonly used technology is to remove fog and dust through the electrostatic precipitator (ESP). The principle is to charge the particles by discharge ionization. , so that it is adsorbed on the plate under the action of an electric field.

The discharge electrode is a part that generates corona current in the electric field. Due to the tip effect of the discharge electrode, the field strength near it is particularly high, so that the electrons gain enough kinetic energy and ionize the gas. The excited electrons and the electrons that have participated in the ionization are all It can continue to participate in ionization, and the number of charges increases rapidly. At the same time, positive ions will also participate in the ionization process, so the performance of the discharge electrode directly affects the efficiency of dust removal and mist removal.

For the discharge electrode, under the same working conditions, it should have the following characteristics: solid and reliable, high mechanical strength, no disconnection, no disconnection; good electrical performance, change the size and distribution of corona inception voltage, current and electric field intensity; The volt-ampere characteristic curve is ideal; the structure is simple, the manufacture is easy, and the cost is low.

Common discharge electrodes include tubular pricked wire, star wire, zigzag wire, fishbone needled wire, helical wire and angle steel pricked wire. Due to the low manufacturing cost and low corona inception voltage of the tubular pricked wire, it is currently used in It is the most widely used domestically, but the linear current density of this line is not uniform enough, which reduces the effective dust collection area. Changing two small thorns into four thorns at the root of the burr can partially solve its disadvantages; the application range is second only Tubular barbed wire is serrated wire, which has low corona inception voltage, good volt-ampere characteristics, easy manufacture, low cost, but high breakage rate.

Utility model content

The purpose of the utility model is to improve the structure of the existing discharge electrode, better realize the dedusting and demisting of the flue gas, and overcome the defects of high cost and low efficiency of the prior art products.

A discharge electrode of an electric precipitator comprises at least one discharge electrode trunk and at least one sawtooth distributed on the side of the discharge electrode trunk.

The discharge electrode may be a single discharge electrode trunk, or may be composed of multiple discharge electrode trunks plugged together. When using multiple discharge electrode trunks, there are installation grooves on the trunk surface of the discharge electrode trunks, the installation grooves are adapted to the thickness of the discharge electrode trunks, and the discharge electrodes are composed of two discharge electrode trunks. plugged into each other. This kind of plug-in method reduces the production cost of the main electrode of multiple discharge electrodes, maintains the mechanical strength of the original discharge electrodes, and can directly use the existing discharge electrodes for installation and assembly. The combination of multiple discharge electrodes is mainly used in the wire barrel structure. The electric field between the different electrodes is evenly distributed, which improves the effective dust removal area and also improves the effective utilization of the ground electrode.

Further, the two ends of the main body of the discharge electrode are provided with hanging devices, which have two purposes, one is to bear the load and mechanical load of the discharge machine system in the electric field, and the other is to insulate the discharge electrode system from the casing, and make the The discharge electrode system is in a high-voltage working state. The device is a bolt, a hole or a welded connecting pipe, which is fixed to the discharge electrode frame, connected with a sleeve or a pillar, and finally connected with a high-voltage power supply system.

Further, the front view shape of the sawtooth is triangular, located on both sides or one side of the main body of the discharge electrode, the distance between adjacent sawtooth is 10-100 mm, and the length of the sawtooth is 50 mm. ~500 mm, the width of the discharge electrode trunk is 20 ~ 200 mm.

Further, the sawtooth plane of the sawtooth coincides with the trunk plane of the discharge electrode trunk. When the sawtooth plane of the sawtooth does not coincide with the trunk plane of the discharge electrode trunk, the distribution of the sawtooth on the discharge electrode trunk can be staggered on different sides, that is, the sawtooth is located on both sides of the discharge electrode trunk On any one side, the orientation of two adjacent serrations is opposite; or it is bilateral and different sides, that is, on any side, all the serrations are facing the same direction, and the serrations on both sides of the main discharge electrode are facing opposite; or It is the same side on both sides, that is, on any side, all the serrations have the same orientation, and the serrations on both sides of the discharge electrode trunk have the same orientation.

In the existing discharge electrode structure, the corona initiation voltage ranges from 15 to 35 kV, and the line current density ranges from 0.87 to 2.02 mA/m. Among them, the corona inception voltage of tubular prickly wire is 15kV, the linear current density is 1.3mA/m, the corona inception voltage of zigzag wire is 20kV, and the linear current density is 1.88mA/m. The sawtooth structure of the sawtooth line can reduce the corona inception voltage and increase the effective corona power per unit time.

At the same time, since there is no discharge tip in the grounding cylinder area, corona discharge does not occur, and there is a dead zone where the current is zero on the grounding plate. The staggered curved sawtooth structure proposed by the utility model has a larger number of discharge tips pointing to the grounding cylinder, which is similar to the new tubular prickly wire structure, which avoids the current dead zone phenomenon, improves the uniformity of the line current density and the effective dust collection area, and increases The effective utilization of the anode plate is improved. This structure improves the efficiency of dust removal and mist removal without changing the distance between the original electrodes.

The discharge electrode structure of the electrostatic precipitator provided by the utility model can purify and control pollutants such as sulfur trioxide, ammonia mist, soot fine particles and aerosols in the flue gas, and has the advantages of simple production, low cost, high strength, high efficiency, It has the characteristics of high voltage on the discharge electrode per unit length and high current density per unit area.

Description of drawings

Fig. 1 a is the structure schematic diagram of discharge electrode of the present invention;

Fig. 1 b is a schematic diagram of the structure of the discharge electrode with perforated grooves of the present invention;

Fig. 1c is the discharge electrode schematic diagram of two discharge electrode trunk plugs of the utility model;

Fig. 2a is a schematic diagram of interlaced discharge electrodes on different sides of the utility model;

Figure 2b is a schematic diagram of bilateral discharge electrodes on different sides of the utility model;

Fig. 2c is a schematic diagram of bilateral discharge electrodes on the same side of the utility model;

Figure 2d is a schematic diagram of the serrated unbent discharge electrode of the present invention;

Fig. 3 is a schematic diagram of the layout of the discharge electrode and the different poles of the present invention;

Fig. 4 is a schematic structural diagram of an electrostatic precipitator according to an embodiment of the utility model.

Detailed ways

The technical solution of the utility model will be described in further detail below in conjunction with the accompanying drawings and embodiments, and the following embodiments do not constitute a limitation of the utility model.

As shown in FIG. 1 a , the discharge electrode 1 of the present invention includes a discharge electrode trunk 2 and sawtooth 3 located on the side of the discharge electrode trunk 2 . The discharge electrode 1 is generally stamped and formed. The discharge electrode 1 of the utility model is generally punched into shape with a steel plate with a thickness of about 2 to 10mm. 50-500mm, generally selected as 100mm, the width of the discharge electrode trunk 2 can be 20-200mm, generally selected as 100mm.

As shown in Figure 1b, there is an installation groove 4 on the main body surface of the discharge electrode trunk 2, and the installation groove 4 is adapted to the thickness of the discharge electrode trunk 2, so that the two discharge electrode trunks 2 are plugged together.

It should be noted that in practical applications, the discharge electrode 1 can use a single discharge electrode trunk 2, as shown in Figure 1a, or two discharge electrode trunks 2 can be plugged together to form a discharge electrode 1, as shown in Figure 1c. Show. It is also possible to increase the number of discharge electrode trunks 2 , such as three discharge electrode trunks 2 combined with one discharge electrode 1 . When stamping and forming, the installation groove 4 can be directly punched out, and the two discharge electrode trunks 2 are inserted in the opposite direction, so that the two discharge electrode trunks 2 can be vertically installed to form the discharge electrode 1 with 8 discharge tips.

It should be noted that the arrangement of the sawtooth 3 on the discharge electrode trunk 2 can be asymmetric on both sides, or symmetrical on both sides, or located only on one side of the discharge electrode trunk 2 . On one side of the main body of the discharge electrode 2, the distance between two adjacent saw teeth 3 can be 10-100 mm, generally 25-50 mm. When the two sides are arranged asymmetrically, they are generally distributed at intervals on both sides to obtain a better electric field distribution. .

Specifically, the front view shape of the sawtooth 3 is a triangle, specifically an isosceles triangle or a right triangle, or other triangles.

As shown in Figure 2, it is a schematic diagram of the distribution of the sawtooth orientation of the discharge electrode of the present invention, showing several situations of relative distribution between the trunk surface of the discharge electrode and the sawtooth surface. After the discharge electrode is punched and formed, the serrated surface can be kept coincident with the main surface of the discharge electrode, or the serrated surface can be bent by a special machine to form a certain angle with the main surface of the discharge electrode. The angle can be 0-360°, generally 135° or 225° °. For the sake of convenience, in this application document, the orientation of the sawtooth 3 is determined by the angle between the serrated surface and the main surface of the discharge electrode, and the orientation of the sawtooth with an angle of less than 180° between the serrated surface and the main surface of the discharge electrode is called outward. The zigzag orientation with the main surface angle of the discharge electrode greater than 180° is called inward, and the relationship between the two orientations is opposite.

Specifically, the orientation distribution of the sawtooth 3 on the discharge electrode trunk 2, as shown in Figure 2a, is staggered on different sides, and the staggered different sides refer to that the sawtooth 3 is distributed on both sides of the discharge electrode trunk 2, and on any side, two adjacent sawtooths 3 The direction is opposite; as shown in Figure 2b, it is the opposite side on both sides, which means that the sawtooth 1 is distributed on both sides of the discharge electrode trunk 2, and on any side, all the sawtooth 3 are facing the same direction, and the sawtooth 3 on both sides of the trunk 2 is facing opposite; as shown in Figure 2c It is shown as the same side on both sides, which means that the serrations 3 are distributed on both sides of the discharge electrode trunk 2. On any side, all the serrations 3 have the same orientation, and the serrations 3 on both sides of the trunk 2 have the same orientation; as shown in Figure 2d, different Curved, not curved means that the serrated surface coincides with the main surface of the discharge electrode.

It should be noted that, the present invention is not limited to the above-mentioned orientation distribution form, and may also be different sides at intervals, random different sides or one side, or any other combination. The different sides of the interval mean that the sawtooth 3 is distributed on both sides of the discharge electrode trunk 2. On any side, after m sawtooth 3 facing the same direction, there will be n sawtooth 3 opposite to the front direction (m, n are any natural numbers); random The opposite side means that the sawtooth 3 is distributed on both sides of the discharge electrode trunk 2, and on any side, the sawtooth 3 faces randomly; one side means that the sawtooth 3 is only distributed on one side of the discharge electrode trunk 2. In engineering use, three zigzag orientation distribution methods are mainly adopted: staggered different sides, bilateral different sides, and bilateral same sides.

Further, bolts, connecting pipes or openings can be welded on both ends of the discharge electrode 1 of the present invention to connect the suspension system and the high-voltage power supply system.

The discharge electrode 1 of the present utility model can be used in an electrostatic precipitator or an electrostatic precipitator in practical applications. Since an electric precipitator is actually a wet electrostatic precipitator, in this application document, an electric precipitator is unified Take as an example to further illustrate the application of the present utility model.

Figure 3 is a cross-sectional view of the utility model discharge electrode 1 and different poles 5 in various arrangements in the electrostatic precipitator, the solid line (——) in the figure is the discharge electrode 1, and the dotted line (---) is the different poles. Pole 5 (ground pole). The arrangement of the discharge electrode 1 and the different pole 5 can be a wire plate type and a wire drum type, and the wire drum type can be a circular tube, a square tube and a hexagonal tube, etc., and the number of the discharge electrodes can be one, two, three or More.

The following is an example of a wire barrel electrostatic precipitator composed of different poles 5 as a square, discharge electrode 1 as two discharge electrode trunks 2, and sawtooth 3 as an example to conduct experiments on flue gas dust removal and fog removal purification. illustrate.

As shown in Figure 4, it is a cross-sectional view and a schematic diagram of a vertical square electrostatic precipitator with different poles 5 (grounding electrodes) of the present utility model. The insulator 6 insulates the discharge electrode system from the casing 8, and is externally connected to the high-voltage power supply 7, so that the discharge electrode 1 is in a high-voltage working state. The insulator 6 is internally connected with the suspension device 9 to bear the load of the discharge electrode 1 in the electric field and other mechanical loads.

A plurality of square heteropoles 5 are located inside the casing 8, and the discharge electrode 1 is arranged in the center of the heteropoles 5 and connected to the hanging device 9 to obtain a high voltage state and a suspended and fixed state. The discharge electrode 1 is in the form of double discharge electrode trunks, and the zigzags are staggered to different sides, as shown in Figure 2a; the two discharge electrode trunks 2 are plugged into each other and are perpendicular to each other, as shown in Figure 1c.

Example 1:

A power plant uses the electric precipitator with double-discharge electrode wire barrels with extremely square grounding of the utility model to control the particulate matter and aerosol in the tail gas after desulfurization. After passing through the desulfurization tower, the flue gas volume before the inlet of the electrostatic precipitator is 102.93×10 ⁴ Nm ³ /h (wet basis), the flue gas temperature is ≤50°C, the SO ₃ concentration is 30mg/Nm ³ , and the fly ash concentration is 20mg/Nm ³ ( dry basis).

1. The high output voltage of the three-phase power supply that provides energy to the wet electrostatic precipitator is 100kV and the current is 2.0A;

2. The diameter of the electrostatic precipitator is 13m, the electrode length is 3.0m, and the grounding electrode is a square tube with a side length of 400mm and a gap of 100mm. The sawtooth length of the discharge electrode is 100mm, the spacing is 25mm, and the width of the discharge electrode trunk is 100mm.

3. The flue gas flow rate is 2.1m/s, and the residence time of the flue gas in the electrostatic precipitator is 1.4s. The total dust collecting area is 3980m ² ;

4. The above three-phase wet electrostatic precipitator has a specific dust collection area of 14.0m ² /(m ³ /s), and an ESP index of 420(kV/cm) ² m ² /(m ³ /s). The current density per unit area is 1.5mA/m ² , and the voltage per unit length is 6kV/cm;

After testing, under the above operating conditions, dust emission < 3mg/Nm ³ , SO ₃ emission < 3mg/Nm ³ , and required process cleaning water < 20m ³ /h can be achieved. The total dust removal efficiency is >95%. Among the classification dust collection efficiency, the dust collection efficiency of particles with a particle size of 0.04 μm is 100%, and the dust collection efficiency of particles with a particle size greater than 1 μm is >98%.

Example 2:

A power plant uses the electric precipitator with double-discharge electrode wire barrels with extremely square grounding of the utility model to control the particulate matter and aerosol in the tail gas after desulfurization. The discharge electrode, flue gas conditions, and the diameter of the three-phase wet electrostatic precipitator are the same as those of the actual embodiment 1. The side length of the ground electrode square tube is changed to 800mm.

1. The high voltage output by the three-phase power supply that provides energy to the wet electrostatic precipitator is changed to 120kV and the current is 1.8A;

2. The above three-phase wet electrostatic precipitator has a specific dust collection area of 7.0m ² /(m ³ /s), and an ESP index of 210(kV/cm) ² m ² /(m ³ /s);

After testing, under the above operating conditions, dust emission < 5mg/Nm ³ , SO ₃ emission < 5mg/Nm ³ , and required process cleaning water < 20m ³ /h can be achieved.

The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding solutions according to the present invention. Changes and deformations, but these corresponding changes and deformations should belong to the scope of protection of the appended claims of the utility model.

Claims (8)

1. A discharge electrode for an electrostatic precipitator, characterized in that the discharge electrode (1) includes at least one discharge electrode trunk (2), and at least one sawtooth ( 3), the main surface of the discharge electrode trunk (2) is provided with an installation groove (4), and the installation groove (4) is adapted to the thickness of the discharge electrode trunk (2). 2 . The discharge electrode according to claim 1 , characterized in that, the discharge electrode ( 1 ) is formed by inserting two discharge electrode trunks ( 2 ) into each other. 3 . 3. The discharge electrode according to claim 1, characterized in that, the two ends of the discharge electrode trunk (2) are provided with hanging devices (9), and the hanging devices (9) are bolts or holes or welding Connecting pipe. 4. The discharge electrode according to any one of claims 1-3, characterized in that, the sawtooth (3) has a triangular shape in front view and is located on both sides of the discharge electrode trunk (2) or On one side, the distance between adjacent sawtooths (3) is 10-100 mm, the length of said sawtooth (3) is 50-500 mm, and the width of said discharge electrode trunk (2) is 20-200 mm . 5. The discharge electrode according to claim 4, characterized in that, the sawtooth plane of the sawtooth (3) coincides with the trunk plane of the discharge electrode trunk (2). 6. The discharge electrode according to claim 4, characterized in that the sawtooth plane of the sawtooth (3) does not coincide with the trunk plane of the discharge electrode trunk (2), and the sawtooth (3) is located on the On both sides of the main body (2) of the discharge electrode, on any side, the orientations of two adjacent sawtooths (3) are opposite. 7. The discharge electrode according to claim 4, characterized in that the sawtooth plane of the sawtooth (3) does not coincide with the trunk plane of the discharge electrode trunk (2), and the sawtooth (3) is located on the On both sides of the discharge electrode trunk (2), on any side, all the serrations (3) face the same direction, and the serrations (3) on both sides of the discharge electrode trunk (2) face opposite. 8. The discharge electrode according to claim 4, characterized in that the sawtooth plane of the sawtooth (3) does not coincide with the trunk plane of the discharge electrode trunk (2), and the sawtooth (3) is located on the On both sides of the discharge electrode trunk (2), on any side, all the serrations (3) have the same orientation, and the serrations (3) on both sides of the discharge electrode trunk (2) have the same orientation. the

Images