Plasma water washing type tail gas treatment device and method

Abstract

This invention discloses a plasma water-washing exhaust gas treatment device and method, including a water curtain chamber and a water washing tower installed on a circulating water tank. The water curtain chamber is circumferentially rotatable and contains an axial water curtain assembly and a circumferential water curtain assembly. The axial water curtain assembly guides water downward to form an axial water curtain with a length along the axial direction of the water curtain chamber and a width along the radial direction of the water curtain chamber. The circumferential water curtain assembly sprays water towards the center of the circumference to form a circumferential water curtain along the radial direction of the water curtain chamber. The water washing tower contains a vertically movable filter dust suppression plate. The filter dust suppression plate has openable and closable water holes and is densely covered with microfiltration pores. When the filter dust suppression plate moves downward, the water holes close, and the dust is pressed down and confined in the dust discharge cavity between the filter dust suppression plate and the bottom of the circulating water tank through water permeation through the microfiltration pores. By performing water curtain cooling and dust suppression and water filtration operations on the exhaust gas, the dust contained in the exhaust gas is removed more efficiently and promptly, avoiding excessive dust from affecting the exhaust gas treatment.

Description

Technical Field

[0001] This invention belongs to the field of exhaust gas treatment technology in industrial production, and particularly relates to a plasma water washing exhaust gas treatment device and method. Background Technology

[0002] Plasma water washing technology is a commonly used technique for purifying exhaust gases generated in industrial production, such as semiconductor and photovoltaic manufacturing. Specifically, nitrogen is ionized into plasma under a strong current, and the resulting high temperature decomposes the exhaust gas. The gas is then sequentially cooled by a water curtain and washed by spray, and finally discharged after meeting standards. Dust in the exhaust gas can easily clog equipment, severely impacting treatment efficiency. Existing water curtain cooling systems use static water curtains, which are easily dispersed by the exhaust gas flow. Due to the limited contact area, dust removal is insufficient, leading to subsequent input of dust-laden exhaust gas into the water washing tower for washing. Furthermore, the dust is not concentrated in the water tank, making removal difficult. The dust dispersed in the water is circulated back to the water curtain cooling and washing processes by a circulating pump, resulting in difficult dust removal and reintroduction into the production process. Summary of the Invention

[0003] Purpose of the invention: In order to overcome the shortcomings of the existing technology, the present invention provides a plasma water washing type exhaust gas treatment device and method, which performs water curtain cooling and dust reduction and water filtration and dust suppression operations on the exhaust gas, thereby removing the dust contained in the exhaust gas more efficiently and in a more timely manner, and avoiding the impact of excessive dust on exhaust gas treatment.

[0004] Technical solution: To achieve the above objectives, the present invention provides a plasma water washing type exhaust gas treatment device, which includes a water curtain chamber and a water washing tower that are respectively connected to a circulating water tank. A gas pipe group and a combustion chamber are arranged sequentially on the water curtain chamber along the exhaust gas input direction, and a plasma torch is installed in the direction corresponding to the central axis of the combustion chamber.

[0005] The water curtain chamber is circumferentially rotatable and contains an axial water curtain assembly and a circumferential water curtain assembly. The axial water curtain assembly guides water downward to form an axial water curtain with a length along the axial direction of the water curtain chamber and a width along the radial direction of the water curtain chamber. The circumferential water curtain assembly sprays water towards the center of the circumference to form a circumferential water curtain along the radial direction of the water curtain chamber. When the water curtain chamber rotates circumferentially, it simultaneously drives the axial water curtain to cover the cooling cavity of the water curtain chamber in a circumferential rotational posture, and simultaneously drives the circumferential water curtain to cover the air inlet of the cooling cavity in a circumferential rotational posture.

[0006] The washing tower is equipped with a vertically movable filter and dust suppression plate. The filter and dust suppression plate is provided with openable and closable water holes and densely distributed microfiltration pores. When the filter and dust suppression plate moves up, the water holes open to allow water to flow through. When the filter and dust suppression plate moves down, the water holes close. The dust is pressed down and limited in the dust discharge bottom cavity between the filter and dust suppression plate and the bottom of the circulating water tank by the water seepage and dust filtration through the microfiltration pores.

[0007] Furthermore, the axial water curtain assembly includes an upper spray pipe and a lower suction pipe; the upper spray pipe and the lower suction pipe are installed radially through the center of the water curtain chamber, and the upper spray hole of the upper spray pipe and the lower suction hole of the lower suction pipe are vertically aligned. The axial water curtain is formed by the water spraying power of the upper spray hole and the water suction power of the lower suction hole.

[0008] Furthermore, the axial water curtain assembly also includes an annular water spray pipe; the annular water spray pipe is connected to the outside of the upper water spray pipe, and the inner ring of the annular water spray pipe has radial water spray holes. The water spray holes impact the upper water spray pipe to form the circumferential water curtain, and the rotating circumferential water curtain forms a cutting action on the exhaust gas flow entering the cooling chamber.

[0009] Furthermore, it includes a support arm corresponding to the water curtain chamber and a rotary drive mechanism; the water curtain chamber is rotatably mounted on the support arm connecting the chassis, and is driven by the rotary drive mechanism to achieve alternating forward and reverse rotation, and the rotation progress in each direction shall not exceed one revolution.

[0010] Furthermore, the circulating water tank is equipped with a circulating water supply pump and a return water pump. The circulating water supply pump supplies water to the upper spray pipe and the annular spray pipe in the water curtain chamber, as well as the spray assembly in the water washing tower. The return water pump provides the suction power to the lower suction pipe in the water curtain chamber.

[0011] Furthermore, the water holes of the filter dust suppression plate are respectively provided with elastic water-driven valves that perform opening and closing actions; the elastic water-driven valve includes a bracket located at the top of the water hole, a valve cover located at the bottom of the water hole, and an elastic component that elastically connects the bracket and the valve cover through the water hole; when the filter dust suppression plate moves up and down, it is driven to perform opening and closing actions by the resistance of the water in the circulating water tank.

[0012] Furthermore, a dust collection plate is provided at the bottom of the circulating water tank, and the space between the filter dust pressing plate and the dust collection plate is the dust discharge bottom cavity; the dust collection plate has a dust collection chamber inside, and dust collection holes that connect to the dust collection chamber are evenly distributed on the top surface of the dust collection plate, and a dust discharge pipe that connects to the dust discharge pump is also connected to the dust collection chamber.

[0013] Furthermore, it includes a lifting drive mechanism corresponding to the water filter and dust suppression plate; the outer periphery of the water filter and dust suppression plate is provided with a plug frame that slides in contact with the inner wall of the circulating water tank, and the lifting drive mechanism drives the water filter and dust suppression plate to lift and lower to realize the water inlet and outlet action.

[0014] Furthermore, the water washing tower consists of a primary water washing tower supplied with water by a circulating water pump and a secondary water washing tower supplied with municipal water.

[0015] A method for treating exhaust gas using a plasma water-washing exhaust gas treatment device includes the following steps:

[0016] Step 1: The plasma torch uses a DC power supply to excite high-purity N2 to generate plasma and high temperature;

[0017] Step 2: Combining the processes of high-temperature plasma decomposition and water dissolution, the exhaust gas generated in the industrial production process is treated at high temperature in the combustion chamber and reacted into powder or water-soluble substances.

[0018] Step 3: Byproducts and dust are cooled by a water curtain in a water curtain chamber;

[0019] Step 4: The byproducts and dust after water curtain cooling are treated by water washing tower spraying to remove them by rinsing or water dissolution, and the gas is sprayed to cool it down.

[0020] Beneficial effects: This invention improves the static water curtain in the water curtain cooling step into a dynamic water curtain, namely an axial water curtain and a circumferential water curtain. The dynamic axial and circumferential water curtains can fully contact the exhaust gas guided through the water curtain chamber, thereby achieving better and more efficient cooling and dust suppression. When the filter dust suppression plate moves down, the water holes close, and the dust is pressed down and limited in the dust discharge bottom cavity between the filter dust suppression plate and the bottom of the circulating water tank through the water seepage of the microfiltration pores. This facilitates the timely removal of the dust already collected in the water and prevents the water circulation containing dust from being introduced into the treatment industry. Attached Figure Description

[0021] Appendix Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0022] Appendix Figure 2 This is a schematic diagram of the internal structure of the equipment in the chassis;

[0023] Appendix Figure 3 This is a schematic diagram of a half-section of the water curtain chamber;

[0024] Appendix Figure 4 This is a schematic diagram of a half-section of the circulating water tank;

[0025] Appendix Figure 5 This is a schematic diagram of the structure of the water filter dust suppression plate and the dust collection plate. Detailed Implementation

[0026] The invention will now be further described with reference to the accompanying drawings.

[0027] As attached Figure 2 As shown, a plasma water-washing exhaust gas treatment device includes a water curtain chamber 4 and a water washing tower 9 respectively connected to a circulating water tank 2. A gas pipe assembly 6 and a combustion chamber 3 are sequentially arranged on the water curtain chamber 4 along the exhaust gas input direction. A plasma torch 5 is installed corresponding to the central axis of the combustion chamber 3. (See attached diagram.) Figure 1 As shown, the inlet 1a of the air pipe group 6 and the outlet 1b of the water washing tower 9 extend from the top of the casing 1.

[0028] As attached Figure 3 As shown, the water curtain chamber 4 is circumferentially rotatable and contains an axial water curtain assembly and a circumferential water curtain assembly. The axial water curtain assembly guides water downward to form an axial water curtain 100 with a length along the axial direction of the water curtain chamber 4 and a width along the radial direction of the water curtain chamber 4. The circumferential water curtain assembly sprays water towards the circumferential center to form a circumferential water curtain 200 along the radial direction of the water curtain chamber 4. When the water curtain chamber 4 rotates circumferentially, it simultaneously drives the axial water curtain 100 to cover the cooling cavity of the water curtain chamber 4 in a circumferential rotational posture, and simultaneously drives the circumferential water curtain 200 to cover the air inlet of the cooling cavity in a circumferential rotational posture. This invention improves the static water curtain in the water curtain cooling step into a dynamic water curtain, namely the axial water curtain 100 and the circumferential water curtain 200. The dynamic axial water curtain 100 and the circumferential water curtain 200 can fully contact the exhaust gas guided by the water curtain chamber 4, thereby achieving better and more efficient cooling and dust suppression.

[0029] In the appendix Figure 2 In this invention, the water curtain chamber 4 and the combustion chamber 3 are connected by an upper rotating connector 7, and the water curtain chamber 4 and the circulating water tank 2 are connected by a lower rotating connector 8. Both the upper rotating connector 7 and the lower rotating connector 8 are rotating connectors.

[0030] As attached Figure 4 As shown, the water washing tower 9 is equipped with a vertically movable filter and dust suppression plate 21. The filter and dust suppression plate 21 is provided with openable and closable water holes 210 and densely packed microfiltration holes 211. When the filter and dust suppression plate 21 moves upward, the water holes 210 open to allow water to pass through. When the filter and dust suppression plate 21 moves downward, the water holes 210 close. The dust is pressed down and limited in the dust discharge bottom cavity 23 between the filter and dust suppression plate 21 and the bottom of the circulating water tank 2 through the water seepage and dust filtration of the microfiltration holes 211. This facilitates the timely removal of the dust collected in the water and prevents the water containing dust from being introduced into the treatment industry.

[0031] As attached Figure 3As shown, the axial water curtain assembly includes an upper spray pipe 18 and a lower suction pipe 17. The upper spray pipe 18 and the lower suction pipe 17 are installed radially through the center of the water curtain chamber 4. The upper spray hole 180 of the upper spray pipe 18 and the lower suction hole 170 on the lower suction pipe 17 are vertically aligned. The water spraying power of the upper spray hole 180 and the water suction power of the lower suction hole 170 work together to form the axial water curtain 100. Therefore, the axial water curtain 100 is structurally strengthened, making it less likely to be dispersed by the exhaust gas flow, ensuring that the deformation of the water curtain is minimized, and making it more conducive to the full contact cooling and dust reduction of the water curtain and exhaust gas.

[0032] As attached Figure 3 As shown, the axial water curtain assembly also includes an annular water spray pipe 19; the annular water spray pipe 19 is connected to the outside of the upper water spray pipe 18, and the inner ring of the annular water spray pipe 19 has radial water spray holes 190. The radial water spray holes 190 impact the upper water spray pipe 18 to form the circumferential water curtain 200. The rotating circumferential water curtain 200 forms a cutting action on the exhaust gas entering the cooling chamber. After the exhaust gas passes through the circumferential water curtain 200 and enters the water curtain chamber 4, it comes into contact with the axial water curtain 100 for cooling. During the process of passing through the circumferential water curtain 200, the circumferential water curtain 200 is also in a rotating state, so that the water jet constituting the circumferential water curtain 200 forms a cutting effect on the exhaust gas in the guiding state, so that the exhaust gas comes into more sufficient contact with the circumferential water curtain 200.

[0033] As attached Figure 3 As shown, the present invention includes a support arm 16 corresponding to the water curtain chamber 4 and a rotary drive mechanism 12. The rotary drive mechanism 12 includes a gear ring 121, a gear 122, and a first servo motor 123. The gear ring 121 is coaxially fixed to the water curtain chamber 4, the gear 122 meshes with the gear ring 121, and the first servo motor 123 is driven by the gear 122. The water curtain chamber 4 is rotatably mounted on the support arm 16 connecting the housing 1, and is driven by the rotary drive mechanism 12 to achieve alternating forward and reverse rotation. The rotation progress in each direction must not exceed one revolution to avoid excessive entanglement of the water guide pipes connecting the axial water curtain components.

[0034] like Figure 2 As shown, the circulating water tank 2 is equipped with a circulating water supply pump 13 and a return water pump 31. The circulating water supply pump 13 supplies water to the upper spray pipe 18 and the annular spray pipe 19 in the water curtain chamber 4, as well as the spray assembly in the water washing tower 9. The return water pump 31 provides the suction power to the lower suction pipe 17 in the water curtain chamber 4. The annular spray pipe 19 has a water inlet 18b, which is connected to the circulating water supply pump 13 through a water supply guide pipe. The lower suction pipe 17 has a water outlet 17a, which is connected to the return water pump 31 through a return water guide pipe.

[0035] As attached Figure 4 As shown, the water holes 210 of the filter dust suppression plate 21 are respectively provided with elastic water-driven valves 26 that perform opening and closing actions; the elastic water-driven valve 26 includes a bracket 261 located at the top of the water hole 210, a valve cover 262 located at the bottom of the water hole 210, and an elastic component 263 that elastically connects the bracket 261 and the valve cover 262 through the water hole 210; when the filter dust suppression plate 21 moves up and down, it is driven to perform opening and closing actions by the resistance of the water in the circulating water tank 2. The elastic component 263 is preferably an elastic telescopic structure rod, which has the directional elastic telescopic property to prevent the valve cover 262 from tilting when it moves.

[0036] More specifically, a dust collection plate 22 is provided at the bottom of the circulating water tank 2, and the space between the filter dust pressing plate 21 and the dust collection plate 22 forms the dust discharge bottom cavity 23. The dust collection plate 22 has a dust collection chamber 220 inside, and dust collection holes 221 are evenly distributed on the top surface of the dust collection plate 22, which are connected to the dust collection chamber 220 and a dust discharge pipe 14 that docks with the dust discharge pump 15. The dust is compressed in the dust discharge bottom cavity 23, which facilitates the use of the dust discharge pump 15 to provide power for rapid and wide-range dust collection and discharge through the dust collection plate 22, resulting in thorough dust removal and high efficiency.

[0037] The present invention includes a lifting drive mechanism 24 corresponding to the water filter and dust suppression plate 21; a plug frame 25 is provided on the outer periphery of the water filter and dust suppression plate 21 to slide in contact with the inner wall of the circulating water tank 2; the lifting drive mechanism 24 drives the water filter and dust suppression plate 21 to lift and lower to realize the water inlet and outlet action. The lifting drive mechanism 24 is composed of a drive screw 241, a guide rod 242, and a second servo motor 243.

[0038] The water washing tower 9 consists of a primary water washing tower 10 supplied with water by a circulating water pump 13 and a secondary water washing tower 11 supplied with municipal water.

[0039] A method for treating exhaust gas using a plasma water-washing exhaust gas treatment device includes the following steps:

[0040] Step 1: Plasma torch 5 generates plasma and high temperature by exciting high-purity N2 with a DC power supply;

[0041] Step 2: Combining the high-temperature plasma decomposition and water dissolution process, the exhaust gas generated by the industrial production process is treated at high temperature in combustion chamber 3 and reacted into powder or water-soluble substances.

[0042] Step 3: Byproducts and dust are cooled by a water curtain in water curtain chamber 4;

[0043] Step 4: The byproducts and dust after water curtain cooling are treated by water washing tower spraying to remove them by rinsing or water dissolution, and the gas is sprayed to cool it down.

[0044] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A plasma water-washing exhaust gas treatment device, comprising a water curtain chamber (4) and a water washing tower (9) respectively connected to a circulating water tank (2), wherein a gas pipe group (6) and a combustion chamber (3) are arranged sequentially on the water curtain chamber (4) along the exhaust gas input direction, and a plasma torch (5) is installed in the direction of the central axis of the combustion chamber (3). Its features are: The water curtain chamber (4) is circumferentially rotatable and is equipped with an axial water curtain assembly and a circumferential water curtain assembly. The axial water curtain assembly guides water downward to form an axial water curtain (100) with a length along the axial direction of the water curtain chamber (4) and a width along the radial direction of the water curtain chamber (4). The circumferential water curtain assembly sprays water towards the center of the circumference to form a circumferential water curtain (200) along the radial direction of the water curtain chamber (4). When the water curtain chamber (4) rotates circumferentially, the axial water curtain (100) is simultaneously driven to cover the cooling cavity of the water curtain chamber (4) in a circumferential rotation posture, and the circumferential water curtain (200) is simultaneously driven to cover the air inlet of the cooling cavity in a circumferential rotation posture. The water washing tower (9) is equipped with a vertically lifting water and dust suppression plate (21). The water and dust suppression plate (21) is provided with openable and closable water holes (210) and densely packed microfiltration holes (211). When the water and dust suppression plate (21) moves upward, the water holes (210) open to allow water to pass through. When the water and dust suppression plate (21) moves downward, the water holes (210) close. The dust is pressed down and limited in the dust discharge bottom cavity (23) between the water and dust suppression plate (21) and the bottom of the circulating water tank (2) by the water seepage and dust filtration through the microfiltration holes (211). The axial water curtain assembly includes an upper spray pipe (18) and a lower suction pipe (17); the upper spray pipe (18) and the lower suction pipe (17) are installed radially through the center of the water curtain chamber (4), and the upper spray hole (180) of the upper spray pipe (18) and the lower suction hole (170) on the lower suction pipe (17) are vertically aligned. The axial water curtain (100) is formed by the water spraying power of the upper spray hole (180) and the water suction power of the lower suction hole (170). The axial water curtain assembly also includes an annular water spray pipe (19); the annular water spray pipe (19) is connected to the outside of the upper water spray pipe (18), and the inner ring of the annular water spray pipe (19) has radial water spray holes (190). The water spray holes (190) impact the upper water spray pipe (18) to form the circumferential water curtain (200), and the circumferential water curtain (200) in the rotating state forms a cutting action on the exhaust gas flow entering the cooling chamber.

2. The plasma water washing type exhaust gas treatment device according to claim 1, characterized in that: It includes a support arm (16) corresponding to the water curtain chamber (4) and a rotary drive mechanism (12); the water curtain chamber (4) is rotatably mounted on the support arm (16) connecting the housing (1), and is driven by the rotary drive mechanism (12) to achieve alternating forward and reverse rotation, and the rotation progress in each direction shall not exceed one revolution.

3. The plasma water washing type exhaust gas treatment device according to claim 2, characterized in that: The circulating water tank (2) is equipped with a circulating water supply pump (13) and a return water pump (31). The circulating water supply pump (13) supplies water to the upper spray pipe (18) and the annular spray pipe (19) in the water curtain chamber (4) and the spray assembly in the water washing tower (9). The return water pump (31) provides water suction power to the lower suction pipe (17) in the water curtain chamber (4).

4. The plasma water washing type exhaust gas treatment device according to claim 3, characterized in that: The water holes (210) of the filter dust suppression plate (21) are respectively provided with elastic water-driven valves (26) that perform opening and closing actions; the elastic water-driven valve (26) includes a bracket (261) located at the top of the water hole (210), a valve cover (262) located at the bottom of the water hole (210), and an elastic component (263) that elastically connects the bracket (261) and the valve cover (262) through the water hole (210); when the filter dust suppression plate (21) moves up and down, it is driven to perform opening and closing actions by the resistance of the water in the circulating water tank (2).

5. The plasma water washing type exhaust gas treatment device according to claim 4, characterized in that: The bottom of the circulating water tank (2) is provided with a dust collection plate (22), and the space between the filter dust pressing plate (21) and the dust collection plate (22) is the dust discharge bottom cavity (23). The dust collection plate (22) has a dust collection cavity (220) inside, and the top surface of the dust collection plate (22) is evenly distributed with dust collection holes (221) that connect to the dust collection cavity (220). The dust collection cavity (220) is also connected to a dust discharge pipe (14) that connects to the dust discharge pump (15).

6. The plasma water-washing exhaust gas treatment device according to claim 5, characterized in that: It includes a lifting drive mechanism (24) corresponding to the water filter and dust suppression plate (21); the outer periphery of the water filter and dust suppression plate (21) is provided with a plug frame (25) that slides in contact with the inner wall of the circulating water tank (2); the lifting drive mechanism (24) drives the water filter and dust suppression plate (21) to lift and lower to realize the water inlet and outlet action.

7. The plasma water-washing exhaust gas treatment device according to claim 6, characterized in that: The water washing tower (9) consists of a primary water washing tower (10) supplied with water by a circulating water pump (13) and a secondary water washing tower (11) supplied with municipal water.

8. A tail gas treatment method based on the plasma water washing tail gas treatment device according to any one of claims 1 to 7, characterized in that: The steps are as follows: Step 1: The plasma torch (5) generates plasma and high temperature by exciting high-purity N2 with a DC power supply; Step 2: Combining the process of high-temperature plasma decomposition and water dissolution, the exhaust gas generated by the industrial production process is treated at high temperature in the combustion chamber (3) and reacted into powder or substances that are soluble in water; Step 3: Byproducts and dust are cooled by a water curtain in the water curtain chamber (4); Step 4: The byproducts and dust after water curtain cooling are treated by water washing tower spraying to remove them by rinsing or water dissolution, and the gas is sprayed to cool it down.

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