CN108905485A - One kind streams and coagulation and cooperates with fine particle and heavy metals trapping device and method - Google Patents

Abstract

The invention relates to a device for trapping fine particles and heavy metals in cooperation with flow-around and electrocoagulation, comprising a casing (1), a baffle dust-collecting plate (2), a positive corona electrode (3), a negative corona electrode (4), A spoiler bar (5); a plurality of baffle dust-collecting plates (2) are arranged in the casing (1), and the flue gas passages in the casing (1) are separated into a plurality of shunt passages, and the adjacent shunt passages are respectively provided with positive The corona pole (3) and the negative corona pole (4) charge particles passing through the adjacent shunting channels with different electric charges, and a plurality of spoiler rods (5) are dispersedly arranged in each shunting channel. Compared with the prior art, the present invention can realize synchronous deep capture of fine particles and heavy metals through the combination of turbulence and electrocoagulation and cooperating devices, combined with subsequent high-efficiency dust collectors.

Description

A device and method for bypassing flow and electrocoagulation and synergistically collecting fine particles and heavy metals

technical field

The invention belongs to the non-ferrous metal smelting flue gas fine particle and heavy metal discharge control technology in the field of environmental protection, and in particular relates to a device and method for bypassing flow and electrocoagulation and coordinating fine particle and heavy metal capture.

Background technique

The output of non-ferrous metals in my country has ranked first in the world for many years, making important contributions to the national economy. However, the industrial flue gas and environmental flue gas collected in the non-ferrous metal smelting process will contain a large amount of dust and heavy metals, which will cause great harm to human health and the environment. At present, the direction of my country's air pollution control has changed from the electric power industry to the non-electric power industry. The Ministry of Environmental Protection has issued emission standards with special limits for the non-ferrous metal smelting industry, and put forward strict emission requirements for fine particles and heavy metals in the flue gas of non-ferrous metal smelting. Therefore, the flue gas pollutants in the non-ferrous metal smelting process need to be treated urgently.

Most non-ferrous smelting enterprises rely on dust removal devices to capture heavy metals and dust in the flue gas. However, heavy metals such as lead/mercury in non-ferrous metal smelting flue gas mostly exist in volatile form under high temperature conditions, and will be converted into fine particles during the cooling process. The existing flue gas dedusting device has relatively low treatment efficiency for fine particles and volatile heavy metals. There is an invention patent CN102125788A, which proposes a method for purifying lead fume and lead dust in the non-ferrous metal industry by using bag dust removal combined with wet jet atomization swirl plate absorption tower. CN102319531A proposes a classification filtering lead dust purification device. These methods can effectively remove most of the dust, but they also have poor treatment effects on fine particles and volatile heavy metals, and cannot meet the requirements of the special emission limits for flue gas in the non-ferrous smelting industry. Therefore, it is necessary to find a new process or method for simultaneous capture of fine particles and volatile heavy metals.

Contents of the invention

The purpose of the present invention is to provide a device and method for bypassing flow and electrocoagulation and cooperating with fine particles and heavy metals in order to overcome the above-mentioned defects in the prior art.

The purpose of the present invention can be achieved through the following technical solutions: a flow-around and electrocoagulation and cooperative fine particle and heavy metal trapping device, characterized in that it includes a casing (1), a baffle dust collecting plate (2), a positive electrode Corona pole (3), negative corona pole (4), spoiler rod (5); a plurality of baffle dust collecting plates (2) are arranged in the shell (1) to separate the flue gas passage in the shell (1) into a Multiple shunt channels, positive corona electrodes (3) and negative corona electrodes (4) are respectively arranged in adjacent shunt channels, and the particles passing through adjacent shunt channels are charged with different charges, and multiple shunt electrodes are scattered in each shunt channel Spoiler (5).

The device also includes a rapping ash removal device (6), a high-voltage power supply (7) and an ash hopper (8), and the rapping ash removal device (6) is arranged on the casing (1) and is connected to a baffle dust collecting plate (2), the high-voltage power supply (7) is respectively connected to the positive corona pole (3) and the negative corona pole (4), and the ash hopper (8) is arranged under each shunt channel, and the The rapping ash removal device (6) is a mechanical rapping device, through which the dust accumulated on the baffle dust collecting plate (2) is shaken down into the ash hopper (8).

The baffled dust-collecting plate (2) has a multi-segment concave-convex structure, including a parallel-section dust-collecting plate parallel to the flue gas flow direction and a baffle-section dust-collecting plate at a certain angle with the flue gas flow direction.

The heights of the two adjacent parallel sections of dust collection plates on the same baffle dust collection plate (2) are different, and are connected by the baffle section dust collection plates, and the parallel section dust collection plates on adjacent baffle dust collection plates (2) are opposite to each other. Setting, the narrowest distance between adjacent baffle dust collection plates is 50-200mm, the widest distance is 100-400mm, the length of the baffle section dust collection plate is 100-150mm, and the length of the parallel section dust collection plate is 300-600mm.

The baffle dust-collecting plate (2) is provided with a plurality of flue gas diversion holes (9), and the diameter of the flue gas diversion holes (9) is 40-100mm, and the adjacent flue gas diversion holes (9) The distance between centers is 40-100mm.

The height to width ratio of the shell (1) is 1:1-1.5:1.

The positive corona poles (3) and negative corona poles (4) are alternately arranged in the flue gas channel, wherein the positive corona poles (3) are located in the front row, connected to the positive pole of the high-voltage power supply (7), and the negative corona poles ( 4) It is located in the back row, connected to the negative pole of the high-voltage power supply (7), and the baffle dust collecting plate (2) is grounded.

The shape of the positive corona pole (3) and the negative corona pole (4) is one of the shapes of star wire, prickly wire, zigzag wire and twisted wire.

The spoiler rod (5) is a polytetrafluoroethylene rod or a polytetrafluoroethylene tube or a metal tube coated with an insulating layer, which reduces dust deposition and enhances coagulation through the same-sex charge repulsion and "back corona" effect. effect;

The short axis of the spoiler (5) is 20-100mm, and the long axis is 1.0-1.5 times of the short axis; the height is 1-5 meters, and the spoiler (5) is arranged on the positive corona pole (3) and the negative corona pole ( 4) Front end 100-500mm.

The high-voltage power supply (7) is a DC power supply with a voltage range of 20-100kV; the positive electrode is connected to the high-voltage pole of the positive high-voltage power supply, the negative pole is connected to the high-voltage pole of the negative power supply, and the baffle dust collecting plate (2) and The shell (1) is used as the ground electrode of the above two power supplies.

The device is installed in the flue section before the bag filter, electrostatic precipitator or electric bag composite dust collector, and the flue gas entering the device has been cooled, and the temperature of the flue gas is between 90-250 degrees. .

A method of using the above-mentioned device to flow around and electrocoagulate and cooperate with fine particles and heavy metals to capture, it is characterized in that it includes the following steps:

In the first step, the flue gas enters the device through the shunt channel formed by the baffle dust collecting plate (2). When passing through the positive corona area (3), some particles are positively charged; The smoke fine particles in the halo area (4) are negatively charged;

In the second step, part of the flue gas continues to advance in the respective shunt channels, and continues to be positively or negatively charged after passing through the spoiler rod (5) and the positive corona area (3) or negative corona area (4);

In the third step, the remaining flue gas enters the adjacent shunt channel through the flue gas guide hole (9) on the baffle dust collecting plate (2), and passes through the spoiler rod (5) and the electrode opposite to the previous stage. The electrodes are charged with different charges;

In the fourth step, the flue gas flows downstream through the gap between the spoiler rod (5) and the baffle integrated plate (2), and the degree of mixing of the airflow and the chance of collision and agglomeration between the fine particles are increased under the action of the turbulence. The particles are thus agglomerated into larger particles;

The fifth step, when the flue gas passes through different corona regions, the fine particles are charged with different charges, and the fine particles collide and agglomerate under the action of opposite sex attraction, and will also agglomerate into larger particles;

Step 6: After the above multiple sets of turbulence and electrocoagulation components, the fine particles are reunited through repeated turbulence and electric charge to form larger particles, and then the large particles are efficiently removed with the help of subsequent bagging or electrostatic precipitator;

In the seventh step, the dust accumulated on the baffle dust collecting plate (2) is vibrated into the ash hopper through the vibrating ash removal device (6).

Compared with prior art, the present invention has following advantages:

1. The present invention charges the fine particles in the flue gas positively or negatively with the help of positive electrodes and negative electrodes arranged in a staggered manner, so that they can be reunited under the action of opposite-sex attraction;

2. The present invention utilizes the turbulence and diversion effect of the spoiler bar and the diversion port on the baffle to strengthen the mixing degree of the flue gas and increase the chance of collision and reunion between fine particles;

3. The present invention uses electrocoagulation to strengthen the adsorption and capture of fine particles to heavy metals;

4. The present invention is also applicable to the cooperative emission control of flue gas fine particles, heavy metals and condensable substances in waste incinerators, metal smelting, cement production and other industries.

Description of drawings

Fig. 1 is the structural representation of device of the present invention;

Fig. 2 is another structural schematic diagram of the device of the present invention.

Detailed ways

The present invention will be further described below in conjunction with specific examples. This embodiment is implemented on the premise of the technical solution of the present invention, and the detailed implementation and specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

The present invention utilizes a pilot-scale flue gas purification device in a laboratory for experimental research. A rotary kiln roasts lead concentrate to provide lead smelting flue gas, and its flue gas volume is 300m ³ /h. After the flue gas is pre-dusted and cooled by the cyclone dust collector, the dust concentration in the flue gas is 8000mg/m ³ , the concentration of heavy metal mercury is 2mg/m ³ , and the temperature is 180°C. After the flue gas passes through a square flue (0.10m0.10m), it is further dedusted by the subsequent bag filter. The dust concentration in the flue gas is reduced to about 50mg/m ³ , and the concentration of heavy metal mercury is 0.50mg/m ³ .

Example 1

In the horizontal section of the flue in front of the bag filter, a small circumvention and electrocoagulation are installed to cooperate with the fine particle and heavy metal trapping device.

As shown in Figures 1 and 2, the circumvention and electrocoagulation cooperate with the fine particle and heavy metal trapping device, including the shell 1, the baffle dust collection plate 2, the positive corona electrode 3, the negative corona electrode 4, the spoiler rod 5, Vibration ash removal device 6, high-voltage power supply 7, ash hopper 8, flue gas guide hole 9; multiple baffle dust collecting plates 2 are arranged in the shell 1, and the flue gas channel in the shell 1 is divided into multiple shunt channels The positive corona electrodes 3 and the negative corona electrodes 4 are respectively arranged in the adjacent shunting channels, and the particles passing through the adjacent shunting channels are charged with different charges, and a plurality of spoiler rods 5 are scattered in each shunting channel. The rapping ash removal device 6 is arranged on the casing 1 and is connected to the baffle dust collecting plate 2, the high voltage power supply 7 is respectively connected to the positive corona pole 3 and the negative corona pole 4, and the ash hopper 8 is set Below each distribution channel, the rapping ash removal device 6 is a mechanical rapping device, through mechanical rapping, the dust accumulated on the baffle dust collecting plate 2 is vibrated into the ash hopper 8 .

The baffled dust-collecting plate 2 has a multi-segment concave-convex structure, including a parallel segment dust-collecting plate parallel to the direction of flue gas flow and a deflected segment dust-collecting plate at a certain angle with the direction of flue gas flow. The heights of two adjacent parallel sections of the same baffle dust collection plate 2 are different, and they are connected by the baffle section dust collection plates. The narrowest distance between the baffle dust collection plates is 100mm, the widest distance is 200mm, the length of the dust collection plate in the baffle section is 100mm, and the length of the dust collection plate in the parallel section is 300mm. A total of 4 rows of electrodes are set up, namely positive corona electrodes 3 (2), negative corona electrodes 4 (1), positive corona electrodes 3 (2) and negative corona electrodes 4 (1), which are located in adjacent baffles. The widest point between the dust collecting panels.

The baffled dust collection plate 2 is provided with a plurality of flue gas diversion holes 9, the diameter of the flue gas diversion holes 9 is 40 mm, and the distance between the centers of adjacent flue gas diversion holes 9 is 40 mm.

The shell 1 has a height of 500mm, a width of 500mm and a length of 1460mm.

The positive corona electrodes 3 and the negative corona electrodes 4 are interlacedly arranged in the flue gas channel, wherein the positive corona electrodes 3 are located in the front row, connected to the positive pole of the high voltage power supply 7, and the negative corona electrodes 4 are located in the rear row, connected to the high voltage power supply 7 negative pole, the baffle dust collecting plate 2 is grounded.

The type of the positive corona pole 3 and the negative corona pole 4 is a star line with a field of 500mm, and a corresponding spoiler 5 is set at the front 100mm of each electrode in the last three rows.

The spoiler rod 5 is a polytetrafluoroethylene rod or a polytetrafluoroethylene tube or a metal tube coated with an insulating layer, which reduces the deposition of dust and enhances the coagulation effect through the same-sex charge repulsion and the "reverse corona" effect;

The short axis of the spoiler 5 is 20mm, and the long axis is 1.5 times of the short axis; the height is 1 meter, and the spoiler 5 is arranged at the front end of the positive corona pole 3 and the negative corona pole 4 by 100mm.

The high-voltage power supply 7 is a DC power supply with a voltage range of 20-100kV; the positive electrode is connected to the high-voltage pole of the positive high-voltage power supply, and the negative pole is connected to the high-voltage pole of the negative power supply. The ground electrode of the two power supplies.

The device is installed in the flue section before the bag filter, electrostatic precipitator or electric bag composite dust collector, and the flue gas entering the device has been cooled, and the temperature of the flue gas is between 90-250 degrees. .

The steps of using the above-mentioned device to purify flue gas are as follows:

In the first step, the flue gas enters the device through the shunt channel formed by the baffle dust collection plate 2. When passing through the positive corona area 3, some particles are positively charged; the flue gas passing through the spoiler 5 and the negative corona area 4 Fine particles are negatively charged;

In the second step, part of the flue gas continues to advance in the respective shunt channels, and continues to be charged with positive or negative charges after passing through the spoiler rod 5 and the positive corona area 3 or the negative corona area 4;

In the third step, the remaining flue gas enters the adjacent shunt channel through the flue gas guide hole 9 on the baffle dust collecting plate 2, and is charged with a different charge after passing through the spoiler bar 5 and the electrode opposite to the previous electrode. ;

In the fourth step, the flue gas flows downstream through the gap between the spoiler bar 5 and the baffle integrated plate 2, and the degree of mixing of the airflow and the chance of collision and agglomeration between the fine particles are increased under the action of the turbulence, and the fine particles are thus agglomerated into larger particles;

The fifth step, when the flue gas passes through different corona regions, the fine particles are charged with different charges, and the fine particles collide and agglomerate under the action of opposite sex attraction, and will also agglomerate into larger particles;

Step 6: After the above multiple sets of turbulence and electrocoagulation components, the fine particles are reunited through repeated turbulence and electric charge to form larger particles, and then the large particles are efficiently removed with the help of subsequent bagging or electrostatic precipitator;

In the seventh step, the dust accumulated on the baffle dust collecting plate 2 is vibrated into the ash hopper through the vibrating ash removal device 6 .

After testing, when the bypass flow and electrocoagulation are installed together with the fine particle and heavy metal capture device, the dust concentration in the outlet flue gas of the bag filter is reduced to about 30mg/ ^m3 , and the concentration of heavy metal mercury is about 0.40mg/m3 ³ .

Example 2

In the horizontal section of the flue in front of the bag filter, a small circumvention and electrocoagulation are installed to cooperate with the fine particle and heavy metal trapping device. The main dimensions of the device are as follows: the height is 500mm, the width is 500mm, and the length is 1460mm. The narrowest width of the baffle dust collection plate is 100mm, and the widest width is 200mm. is 300mm, and the diameter of the diversion hole is 50mm. A total of 4 rows of electrodes are set up, which are positive electrodes (2), negative electrodes (1), positive electrodes (2) and negative electrodes (1). The electrodes are star-shaped, with a field of 500mm. A corresponding spoiler is set at 100mm, the short axis of the spoiler is 20mm, the long axis is 30mm of the short axis, and the length is 500mm. The distance between the flow rod and the center of the electrode and the wall of the baffle plate is 100 mm. Connect the first and third rows of electrodes to the positive pole of the high-voltage power supply; connect the second and fourth rows of electrodes to the negative pole of the high-voltage power supply; Adjust the positive supply voltage to 20kV and the negative supply voltage to 20kV. After testing, after the dual functions of charge coagulation, flow disturbance and flow diversion, the particle concentration at the outlet of the bag filter dropped to 15mg/m ³ , and the concentration of heavy metal mercury was about 0.20mg/m ³ .

Example 3

In the horizontal section of the flue in front of the bag filter, a small circumvention and electrocoagulation are installed to cooperate with the fine particle and heavy metal trapping device. The main dimensions of the device are as follows: the height is 500mm, the width is 500mm, and the length is 1460mm. The narrowest width of the baffle dust collection plate is 100mm, and the widest width is 200mm. is 300mm, and the diameter of the diversion hole is 50mm. A total of 4 rows of electrodes are set up, which are positive electrodes (2), negative electrodes (1), positive electrodes (2) and negative electrodes (1). The electrodes are star-shaped, with a field of 500mm. A corresponding spoiler is set at 100mm, the short axis of the spoiler is 20mm, the long axis is 30mm of the short axis, and the length is 500mm. The distance between the flow rod and the center of the electrode and the wall of the baffle plate is 100 mm. Connect the first and third rows of electrodes to the positive pole of the high-voltage power supply; connect the second and fourth rows of electrodes to the negative pole of the high-voltage power supply; Adjust the positive supply voltage to 40kV and the negative supply voltage to 40kV. After testing, after the dual effects of charge coagulation, flow disturbance and flow diversion, the concentration of particulate matter at the outlet of the bag filter dropped to 8mg/m ³ , and the concentration of heavy metal mercury was about 0.05mg/m ³ .

Claims (12)

1. A flow-around and electrocoagulation and synergistic fine particle and heavy metal trapping device are characterized in that, comprise shell (1), baffle dust-collecting plate (2), positive corona pole (3), negative corona pole ( 4), spoiler bar (5); a plurality of baffle dust collecting plates (2) are arranged in the shell (1), and the flue gas channel in the shell (1) is divided into a plurality of shunt channels, and the adjacent shunt channels Positive corona poles (3) and negative corona poles (4) are arranged respectively to charge particles passing through adjacent shunting channels with different electric charges, and a plurality of spoiler rods (5) are dispersedly arranged in each shunting channel. 2. A device for bypassing flow and electrocoagulation and cooperating with fine particles and heavy metals according to claim 1, characterized in that the device also includes a rapping ash removal device (6), a high-voltage power supply (7) and the ash hopper (8), the rapping ash removal device (6) is arranged on the casing (1), and connected to the baffle dust collecting plate (2), and the described high-voltage power supply (7) is respectively connected to the positive corona pole (3) and negative corona pole (4), the ash hopper (8) is arranged under each shunt channel, the rapping ash removal device (6) is a mechanical rapping device, and the rich The dust collected on the baffle dust collecting plate (2) vibrates and falls among the ash hopper (8). 3. A flow-around and electrocoagulation and cooperation fine particle and heavy metal trapping device according to claim 1, characterized in that, the baffle dust collecting plate (2) has a multi-stage concave-convex structure, including The dust collecting plate in the parallel section parallel to the air flow direction and the dust collecting plate in the baffle section forming a certain angle with the flow direction of the flue gas. 4. A kind of circumvention and electrocoagulation and cooperating fine particle and heavy metal trapping device according to claim 3, characterized in that, on the same baffle dust collection plate (2), two adjacent parallel section dust collection plates The heights are different, and they are connected by the dust-collecting plates of the baffle section, and the dust-collecting plates of the parallel sections on the adjacent baffle dust-collecting plates (2) are arranged opposite to each other. The narrowest distance between adjacent baffle dust-collecting plates is 50-200mm, and the widest The distance is 100-400mm, the length of the dust collection plate in the baffle section is 100-150mm, and the length of the dust collection plate in the parallel section is 300-600mm. 5. A flow-around and electrocoagulation and fine particle and heavy metal trapping device according to claim 3, characterized in that, the baffle dust-collecting plate (2) is provided with a plurality of flue gas guides Holes (9), the diameter of the flue gas diversion holes (9) is 40-100mm, and the distance between the centers of adjacent flue gas diversion holes (9) is 40-100mm. 6. A flow-around and electrocoagulation and cooperation fine particle and heavy metal trapping device according to claim 1, characterized in that, the height-to-width ratio of the housing (1) is 1:1-1.5:1 . 7. A flow-around and electrocoagulation and cooperating fine particle and heavy metal trapping device according to claim 2, characterized in that the positive corona poles (3) and negative corona poles (4) are alternately arranged at In the flue gas channel, the positive corona electrode (3) is located in the front row, connected to the positive electrode of the high-voltage power supply (7), the negative corona electrode (4) is located in the rear row, connected to the negative electrode of the high-voltage power supply (7), and the baffle dust collection plate (2) Grounding. 8. A device for bypassing flow and electrocoagulation and cooperating with fine particulate matter and heavy metal trapping according to claim 1, characterized in that, the types of the positive corona pole (3) and the negative corona pole (4) are: One of the shapes of star line, prickly line, zigzag line and twist line. 9. A device for bypassing flow and electrocoagulation and cooperating with fine particles and heavy metals according to claim 1, characterized in that, the spoiler rod (5) is a polytetrafluoroethylene rod or polytetrafluoroethylene Tubes or metal tubes coated with an insulating layer can reduce dust deposition and enhance coagulation through the same-sex charge repulsion and "reverse corona" effect; The short axis of the spoiler (5) is 20-100mm, and the long axis is 1.0-1.5 times of the short axis; the height is 1-5 meters, and the spoiler (5) is arranged on the positive corona pole (3) and the negative corona pole ( 4) Front end 100-500mm. 10. A flow-around and electrocoagulation and fine particle and heavy metal trapping device according to claim 2, characterized in that the high-voltage power supply (7) is a DC power supply with a voltage range of 20-100kV The positive electrode is connected to the high-voltage pole of the positive high-voltage power supply, and the negative pole is connected to the high-voltage pole of the negative power supply. 11. A flow-around and electrocoagulation combined fine particle and heavy metal trapping device according to claim 1, characterized in that the device is arranged before the bag filter, electrostatic precipitator or electric bag composite precipitator In the flue section, the flue gas entering the device has been cooled, and the temperature of the flue gas is between 90-250 degrees. 12. A method of using the device according to any one of claims 1-11 to flow around and electrocoagulate and cooperate with the capture of fine particles and heavy metals, characterized in that it comprises the following steps: In the first step, the flue gas enters the device through the shunt channel formed by the baffle dust collecting plate (2). When passing through the positive corona area (3), some particles are positively charged; The smoke fine particles in the halo area (4) are negatively charged; In the second step, part of the flue gas continues to advance in the respective shunt channels, and continues to be positively or negatively charged after passing through the spoiler rod (5) and the positive corona area (3) or negative corona area (4); In the third step, the remaining flue gas enters the adjacent shunt channel through the flue gas guide hole (9) on the baffle dust collecting plate (2), and passes through the spoiler rod (5) and the electrode opposite to the previous stage. The electrodes are charged with different charges; In the fourth step, the flue gas flows downstream through the gap between the spoiler rod (5) and the baffle integrated plate (2), and the degree of mixing of the airflow and the chance of collision and agglomeration between the fine particles are increased under the action of the turbulence. The particles are thus agglomerated into larger particles; The fifth step, when the flue gas passes through different corona regions, the fine particles are charged with different charges, and the fine particles collide and agglomerate under the action of opposite sex attraction, and will also agglomerate into larger particles; Step 6: After the above multiple sets of turbulence and electrocoagulation components, the fine particles are reunited through repeated turbulence and electric charge to form larger particles, and then the large particles are efficiently removed with the help of subsequent bagging or electrostatic precipitator; In the seventh step, the dust accumulated on the baffle dust collecting plate (2) is vibrated into the ash hopper through the vibrating ash removal device (6).