Steam mixing water washing type tail gas treatment system

Abstract

The invention discloses a steam mixing water washing type tail gas treatment system which comprises a transverse gas guiding water washing chamber, and tail gas decomposed by a plasma reaction cavity sequentially penetrates through the water washing chamber and a spray tower and then is discharged; the water washing chamber comprises a mixing cavity, and double water curtains surrounding the air inlet pipe are formed in the mixing cavity; a mixing area is formed between two water curtains of the double water curtains, the mixing area is filled with water vapor, tail gas transversely penetrates through the double water curtains to form mixed tail gas, the mixed tail gas enters a cooling channel, the cooling channel can conduct multi-stage cooling on the mixed tail gas, and the mixed tail gas is distributed into a convection cavity in a rime fog state; longitudinal water spraying areas which are evenly distributed are formed in the convection cavity, and the mixed tail gas in the rime fog state rises in the convection cavity and evenly penetrates through the longitudinal water spraying areas to form harmless tail gas. And the harmless tail gas continuously rises to enter the spray tower. According to the invention, soluble harmful products generated after plasma decomposition of tail gas can be fully absorbed.

Description

Technical Field

[0001] The present invention relates to the technical field of plasma waste gas treatment, and particularly to a vapor mixed water washing type tail gas treatment system. Background Art

[0002] Plasma waste gas treatment devices are commonly used for the pretreatment of toxic tail gas emissions. They can generate powders or substances soluble in water through high-temperature reactions of the waste gas, and then separate the generated powders and substances from the gas through water washing and filtration. Finally, the washed tail gas is discharged. This usually requires a large amount of water consumption. Moreover, due to the differences in the water solubility and the ease of dissolution of different tail gas decomposition products, when dealing with different tail gases, the absorption and treatment effects produced are different. It may lead to the emission of some toxic substances with the tail gas due to insufficient water washing and absorption. Summary of the Invention

[0003] Object of the Invention: In order to overcome the deficiencies existing in the prior art, the present invention provides a vapor mixed water washing type tail gas treatment system, which can fully wash and absorb the decomposition products in the tail gas treatment.

[0004] Technical Solution: To achieve the above object, a vapor mixed water washing type tail gas treatment system of the present invention includes a water washing chamber for horizontal gas guiding. The upper part of the water washing chamber is connected and installed with a plasma reaction chamber and a spray tower for vertical gas guiding. The tail gas decomposed by the plasma reaction chamber sequentially passes through the water washing chamber and the spray tower and then is discharged;

[0005] The water washing chamber includes a mixing chamber, and a double water curtain is formed in the chamber around the intake pipe; the double water curtain includes two longitudinal water curtains, and a mixing area is formed between the two water curtains. The mixing area is filled with water vapor. The tail gas horizontally passes through the double water curtain and then forms a mixed tail gas and enters a cooling channel. The cooling channel can perform multi-stage cooling on the mixed tail gas and make the mixed tail gas be arranged in the convection chamber in a white mist state;

[0006] A uniformly distributed longitudinal water spraying area is formed in the convection chamber. The mixed tail gas in the white mist state rises in the convection chamber and uniformly passes through the longitudinal water spraying area to form harmless tail gas; the harmless tail gas continues to rise and enters the spray tower.

[0007] Further, the cooling channel includes a plurality of cooling intervals arranged horizontally, and the mixed tail gas can rise to the convection chamber after horizontally passing through each cooling interval, and a longitudinally rising wind field is formed on the gas outlet side of each cooling interval (61).

[0008] Further, the intake pipe longitudinally extends into the mixing chamber, and a set of water curtain nozzles are respectively arranged on both sides of the intake pipe. The water curtain nozzles can eject refined droplets and droplets larger than the droplets, and simultaneously spray them on the outer wall of the intake pipe and the inner wall of the mixing chamber. The droplets sprayed on the two walls can converge to form the double water curtain. The spraying position of the droplets is on the upper side of the spraying position of the droplets, for generating water vapor.

[0009] Further, a temperature sensor is arranged in the convection chamber, and the temperature sensor is electrically connected to the flow electric control valve of the water curtain nozzle through a controller.

[0010] Further, a water network evenly covering the ventilation cross-section is formed within the cooling range. The water network is composed of evenly dispersed droplets. The water network can cool the water vapor in the mixed exhaust gas to form flowing water mist mixed with the exhaust gas. The flowing water mist can absorb and dissolve the gas products easily soluble in water in the exhaust gas together with the water network. The flowing water mist dissolved with the gas products forms the mixed exhaust gas in a white mist state.

[0011] Further, the water network is composed of the overlap of two sets of conical water mist sprayed horizontally. Each set includes several conical water mist, and they are arranged along the length direction of the ventilation cross-section, and there is an overlap in the edge area of two adjacent conical water mist; the two sets of conical water mist are parallel to each other in the ventilation direction, and in the perspective of the ventilation cross-section, a plurality of the conical water mist of the two are arranged in a staggered manner in their own arrangement direction.

[0012] Further, a water baffle is arranged on the upper side of the cooling channel. The water baffle is provided with an upward ventilation port on the exhaust gas passing-through side of the water network; a gas distribution grid plate is arranged at an interval on the upper side of the water baffle.

[0013] Further, a high-density aerosol area is formed at the connection port between the upper part of the convection chamber and the lower end of the spray tower, which can form an inhibitory force on the upward diffusion trend of the mixed exhaust gas in the white mist state.

[0014] Further, a water collecting tank is arranged at the lower part of the water washing chamber, which can collect the water falling in the water washing chamber and the spray tower, and can supply water to the multiple water networks in a cycle by pumping through a water pump;

[0015] The water collecting tank is provided with a substance concentration detection sensor and a water level monitoring sensor, and both are electrically connected to the opening and closing control module of the drainage pump through a controller.

[0016] Furthermore, a plurality of spray heads arranged longitudinally are provided in the spray tower, and a packing area is provided below each layer of the spray heads. The spray water can uniformly pass through the packing area under the action of gravity and uniformly drip from the lower port of the spray tower, so as to form the longitudinal water spraying area in the convection cavity.

[0017] Beneficial effects: In a vapor mixed water washing type tail gas treatment system of the present invention, the tail gas containing a large amount of powder and soluble substances after decomposition is first subjected to a large amount of dust removal and mixed with water vapor to improve the ability to dissolve and capture soluble substances during the gas flow process, and by controlling the temperature of the main dissolution area, the dissolution efficiency and solubility are improved. Finally, the interception rate of harmful soluble substances is increased in the form of longitudinal impact, ensuring the purification degree of the discharged tail gas. Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of an embodiment of a vapor mixed water washing type tail gas treatment system of the present invention;

[0019] Figure 2 It is a schematic diagram of the formation of a water network within a single temperature reduction interval. Detailed Embodiments

[0020] The present invention will be further described in detail below with reference to the drawings.

[0021] As shown in the attached Figure 1-2 The described vapor mixed water washing type tail gas treatment system includes a water washing chamber 1 for transverse gas guiding. The upper part of the water washing chamber 1 is connected and installed with a plasma reaction chamber 2 for longitudinal gas guiding and a spray tower 3. The tail gas decomposed by the plasma reaction chamber 2 sequentially passes through the water washing chamber 1 and the spray tower 3 and then is discharged. The tail gas is decomposed into powder and soluble substances in the plasma reaction chamber, and is fully washed and absorbed in the water washing chamber to remove most of the powder and completely absorb the soluble substances. Finally, the remaining powder is washed off in the spray tower and cooled to a reasonable temperature, and is discharged after gas-liquid separation, without the overflow of harmful substances, reducing the pollution to the working environment.

[0022] The washing chamber 1 includes a mixing chamber, in which a double water curtain is formed around the intake pipe 11; the double water curtain includes two longitudinal water curtains 4, and a mixing area 5 is formed between the two water curtains 4. The mixing area 5 is filled with water vapor, and the tail gas passes through the double water curtain horizontally and then forms a mixed tail gas and enters the cooling channel 6; when the tail gas after reaction decomposition passes through the first longitudinal water curtain, relatively sparse and larger water droplets accelerate through the air flow under the action of gravity, taking most of the powder particles out of the air flow and falling into the water tank below. Subsequently, the air flow is fully mixed with water vapor in the mixing area, and with the help of the disturbance of the remaining powder particles in the air flow, the mixing efficiency is accelerated to form a mixed tail gas. When the mixed tail gas passes through the second water curtain, a large amount of powder is further removed, and only a small amount of fine powder particles remain and enter the cooling channel with the air flow.

[0023] The cooling channel 6 can perform multi-stage cooling on the mixed tail gas and distribute the mixed tail gas into the convection chamber 7 in a white mist state; through the cooling effect of the cooling channel, the water vapor mixed in the tail gas is quickly liquefied and condensed into small droplets with the remaining powder in the gas as the core. Due to the full mixing of water vapor and the tail gas, the formed small droplets can fully contact and absorb the soluble substances in the tail gas, and then form small droplets in a state of dissolved decomposition products, showing a white mist state. And the cooling channel can reduce the temperature of the tail gas to the optimal water solubility temperature range of the soluble substances in the tail gas, ensuring that most of the soluble substances are dissolved in the small fog droplets. If there are multiple water-soluble substances in the tail gas, the tail gas passing through the cooling channel will be cooled to the lowest optimal dissolution temperature of the multiple substances.

[0024] A uniformly distributed longitudinal water spraying area is formed in the convection chamber 7. The mixed tail gas in the white mist state rises in the convection chamber 7 and evenly passes through the longitudinal water spraying area to form harmless tail gas; the longitudinal convection relationship between the white mist air flow and the sprayed water flow can increase the collision probability of the white mist droplets and the purified water droplets, and can carry most of the droplets dissolved with substances to fall into the water tank below. At the same time, the temperature of the rising tail gas is further reduced, so that the temperature of the tail gas is reduced below the boiling point of the dissolved substances, avoiding the re-volatilization of the already dissolved substances.

[0025] Based on the mixing reaction of water vapor and the control of the optimal dissolution temperature range of the cooling channel, almost all soluble substances are dissolved and absorbed. Even if there are a small amount of undissolved substances, under the action of the dense water spraying area, they can also be fully dissolved and absorbed.

[0026] The harmless tail gas continues to rise and enters the spray tower 3, which can finally remove dust, cool down and dehydrate the tail gas that has removed harmful substances, ensuring that the discharged tail gas is clean and relatively dry.

[0027] The cooling channel 6 includes a plurality of laterally arranged cooling intervals 61. After the mixed tail gas passes through each cooling interval 61 horizontally, it can rise into the convection chamber 7. A longitudinally rising wind field is formed on the gas outlet side of each cooling interval (61). By adjusting the number of cooling intervals through which the tail gas passes, the temperature of the tail gas when it enters the convection chamber through the cooling channel can be controlled, ensuring that the water-soluble substances in the tail gas are just in the optimal dissolution temperature when they are located in the cooling channel. The wind fields at the rear of each cooling interval are controlled to open and close independently, and only a single wind field is controlled to open each time, depending on the number of cooling intervals that the tail gas needs to pass through, which helps to form a lateral resistance, enabling the tail gas to quickly turn upward and enter the convection chamber after passing through the expected cooling intervals, thereby improving the treatment efficiency of the tail gas. Correspondingly, according to the number of cooling intervals that the tail gas needs to pass through, several cooling intervals on the side of the wind field away from the tail gas input side can be temporarily stopped from working. For example, if water network cooling is used, the water supply can be stopped to save water consumption.

[0028] Preferably, a layer of mesh plate can be arranged on the lower side of the cooling channel for uniform air distribution, and a movable air outlet can be arranged under the mesh plate for blowing upward through the mesh plate to form a uniform longitudinal wind field. The air outlet can move to the gas outlet side of the corresponding cooling interval according to the number of cooling intervals preset for the tail gas to pass through. Thus, the installation position can be freely selected according to the temperature control requirements. Moreover, the upward wind field is beneficial to enhancing the upward speed of the tail gas, strengthening the convection effect with the water spraying area, and further enhancing the interception effect on the dissolved substances, ensuring that harmful substances remain inside the equipment.

[0029] On this basis, the double water curtain can increase the flow rate, further increasing the resistance to the lateral gas transmission of the mixed tail gas. This enables the tail gas passing through the cooling channel to freely select the number of cooling intervals to pass through and enter the convection chamber 7 after passing through any cooling interval, accelerating the interception of harmful substances.

[0030] When the optimal dissolution temperature of the soluble substances in the tail gas is relatively high, the flow rate of the double water curtain can be appropriately increased, and vice versa. More precisely, a temperature sensor can be arranged in the bottom area of the convection chamber for controlling the flow rate of the double water curtain, selecting and controlling the opening and closing of the longitudinal wind field, and controlling the opening and closing of the cooling intervals.

[0031] The air inlet pipe 11 extends longitudinally into the mixing chamber, and a group of water curtain nozzles 41 are respectively provided on both sides of the air inlet pipe 11. The water curtain nozzles 41 are capable of spraying fine droplets and relatively larger droplets, and spraying them simultaneously on the outer wall of the air inlet pipe 11 and the inner wall of the mixing chamber. The droplets sprayed on the two walls can converge to form the double water curtain. The droplet spraying position is above the droplet spraying position, which is used to generate water vapor. Due to the high temperature of the air inlet pipe, a waterfall-like water curtain is formed on the outer wall of the air inlet pipe, which can first cool the lower section of the air inlet pipe. The water curtain nozzles 41 can simultaneously act on the two side walls by spraying an annular water mist upward. The relatively larger droplets will fall on the lower wall to form a water curtain, while the relatively smaller droplets are lighter and sprayed higher, contacting the relatively higher temperature pipe wall on the upper side, and quickly evaporate to form water vapor.

[0032] A temperature sensor is provided in the convection chamber 7 , and the temperature sensor is electrically connected to the flow electric control valve of the water curtain nozzle 41 through a controller.

[0033] A water net 62 that evenly covers the ventilation cross section is formed in the cooling zone 61. The water net 62 is composed of evenly scattered mist droplets. The water net 62 can cool the water vapor in the mixed exhaust gas to form a flowing water mist mixed with the exhaust gas. The flowing water mist can absorb and dissolve the gas products that are easily soluble in water in the exhaust gas together with the water net 62. The flowing water mist with dissolved gas products forms the mixed exhaust gas in a white mist state. After the exhaust gas mixes with water vapor, it passes through the water network formed by fog droplets. Compared with passing through the water network directly, soluble substances are more easily captured. Since the water network formed by fog droplets is relatively dense, there are still gaps between the fog droplets, and the gaps are quite large for gas molecules, so it is difficult to achieve 100% capture and absorption. Water vapor is first mixed with the exhaust gas in gaseous form, and then passes through the water network. The water droplets formed by condensation can fill this part of the gap, thereby more fully capturing and absorbing water-soluble substances, allowing most of the substances to float into the convection cavity in a dissolved state. The white mist droplets formed by the dissolution are larger than the gas molecules, and the probability of colliding with the falling water droplets is greater, and the resulting interception effect is better.

[0034] In addition, considering temperature control, when the number of water networks that the air flow passes through horizontally is smaller, the dissolution time is shorter. Although most of the easily soluble substances are dissolved due to the improved dissolution efficiency, the small amount of remaining undissolved part is relatively high compared to the tail gas passing through multiple water networks. Then, the requirement for the dissolution and absorption capacity of the convection chamber increases. And in this solution, the horizontal resistance of the air flow is controlled by adjusting the size of the water curtain flow rate. While reducing the temperature adjustment amount by increasing the resistance, the water curtain with an increased flow rate will enhance the dissolution and interception effect of the easily soluble substances to a certain extent, so as to shift the possible increased treatment load of the convection chamber to the double water curtain in advance, ensuring that the harmful and easily soluble substances can be completely separated from the exhausted tail gas after passing through the convection chamber.

[0035] The water network 62 is composed of the overlap of two groups of conical water mists 621 ejected horizontally. Each group includes several of the conical water mists 621, and they are arranged along the length direction of the ventilation cross-section, and there is an overlap in the edge area of two adjacent conical water mists 621; the two groups of conical water mists 621 are parallel to each other in the ventilation direction, and in the perspective of the ventilation cross-section, a plurality of the conical water mists 621 of the two are arranged in a staggered manner in their own arrangement direction. Common nozzles that can eject conical water mists, and the water mist in the outer circle is relatively very small and thinner than that in the inner circle, and the gap is larger. By overlapping the outer circle parts of two adjacent conical water mists, the density degree of the whole water mist can be made more uniform. However, there may still be a certain difference between the overlapping area and the separate inner circle area. Then, through the staggered arrangement between two progressive water networks, the air flow can alternately pass through the overlapping area and the inner circle area, so as to obtain the best dissolution and capture effect.

[0036] A water baffle 8 is arranged on the upper side of the cooling channel 6, and the water baffle 8 is provided with an upward ventilation opening on the side where the tail gas of the water network 62 passes through; a gas distribution grid plate 9 is arranged at an interval above the water baffle 8. A laterally connected gas distribution space is formed between the water baffle 8 and the gas distribution grid plate 9. No matter which ventilation opening the tail gas enters the gas distribution space from, it can first fill the gas distribution space, and then pass through the gas distribution grid plate and be evenly distributed into the convection chamber, so as to fully contact the water pouring down and obtain the best interception effect.

[0037] A high-density aerosol area is formed at the connection port between the upper part of the convection chamber 7 and the lower end of the spray tower 3, which can form an inhibitory force on the upward diffusion trend of the mixed tail gas in the white mist state. Through a plurality of aerosol nozzles around the connection port spraying water mist upward, an overlapping aerosol area is formed below the connection port. First, it can increase the resistance of the tail gas to move upward, making the relative pressure in the convection chamber rise. In a high-pressure environment, it is helpful for the dissolution of the remaining tail gas, and by extending the residence time of the tail gas in the convection chamber, the full absorption of harmful substances is ensured.

[0038] A water collecting tank 10 is provided at the lower part of the water washing chamber 1, which can collect the water falling from the water washing chamber 1 and the spray tower 3, and can supply water to the plurality of water meshes 62 in a circulating manner by means of a water pump; the water collecting tank 10 is the above-mentioned water tank, and the water collecting tank 10 can be divided into two parts, one part is located below the double water curtain, such as Figure 1 the left water tank, and the other part is located below the cooling channel and the convection chamber, such as Figure 1 the right water tank. The water in the left water tank is pumped to supply water to the mesh 62, and the left and right water tanks are connected at a high water level. Substance concentration detection sensors and water level monitoring sensors are arranged in both parts of the water collecting tank 10, and are electrically connected to the opening and closing control module of the drain pump through a controller. The water level on the left side remains relatively stable due to stable pumping, while the water level in the right water tank gradually rises. When it reaches the connection height, it overflows to the left water tank. When the liquid concentration in the right water tank does not exceed the standard, part of the water dissolved with substances can be overflowed to the left and diluted by the water curtain inlet, and then introduced into the water supply pipeline of the water mesh until the concentration of harmful substances in the right water body exceeds the standard, and then the water in the right water tank is pumped and discharged to the corresponding plant utility treatment. The substance concentration detection sensor in the left water tank is used to detect the concentration of solid particles in the water body. Similarly, when it exceeds the standard, a certain amount of water is pumped and discharged, and a part is reserved for the water supply of the water mesh, and the water layer with a higher concentration of solid particles is preferentially pumped and discharged. The water level monitoring sensor is arranged above the connection height of the left and right water tanks. When the water levels in both water tanks reach a relatively high level, both sides are pumped and discharged simultaneously.

[0039] A plurality of longitudinally arranged spray heads 31 are provided in the spray tower 3, and a packing area is provided below each layer of the spray heads 31. The spray water can uniformly pass through the packing area under the action of gravity and uniformly drip at the lower port of the spray tower 3, so as to form the longitudinal water spraying area in the convection chamber 7.

[0040] The above description is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the above principles of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. A vapor mixing and water washing type tail gas treatment system, characterized in that: It includes a water washing chamber (1) with horizontal gas conduction. The upper part of the water washing chamber (1) is connected and installed with a plasma reaction chamber (2) and a spray tower (3) with vertical gas conduction. The tail gas decomposed by the plasma reaction chamber (2) passes through the water washing chamber (1) and the spray tower (3) in sequence and then is discharged. The water washing chamber (1) includes a mixing chamber, and a double water curtain is formed in the chamber around the air inlet pipe (11). The double water curtain includes two longitudinal water curtains (4), and a mixing area (5) is formed between the two water curtains (4). The mixing area (5) is filled with water vapor. The tail gas passes through the double water curtain horizontally and then forms a mixed tail gas and enters the cooling channel (6). The cooling channel (6) can cool the mixed tail gas in multiple stages and make the mixed tail gas be distributed into the convection chamber (7) in a white fog state. A uniformly distributed longitudinal water spraying area is formed in the convection chamber (7). The mixed tail gas in the white fog state rises in the convection chamber (7) and uniformly passes through the longitudinal water spraying area to form harmless tail gas. The harmless tail gas continues to rise and enters the spray tower (3).

2. The vapor mixing and water washing type tail gas treatment system according to claim 1, characterized in that: The cooling channel (6) includes a plurality of cooling intervals (61) arranged horizontally. The mixed tail gas can rise into the convection chamber (7) after passing through each cooling interval (61) horizontally. And a longitudinally rising wind field is formed on the gas outlet side of each cooling interval (61).

3. The vapor mixing and water washing type tail gas treatment system according to claim 2, characterized in that: The air inlet pipe (11) extends longitudinally into the mixing chamber. A group of water curtain nozzles (41) are respectively arranged on both sides of the air inlet pipe (11). The water curtain nozzles (41) can spray refined mist droplets and droplets larger than the mist droplets, and spray them on the outer wall of the air inlet pipe (11) and the inner wall of the mixing chamber at the same time. The droplets can converge on the two wall bodies to form the double water curtain. The spraying position of the mist droplets is on the upper side of the spraying position of the droplets, which is used to generate water vapor.

4. The vapor mixing and water washing type tail gas treatment system according to claim 3, characterized in that: A temperature sensor is arranged in the convection chamber (7). The temperature sensor is electrically connected to the flow electric control valve of the water curtain nozzle (41) through a controller.

5. The vapor mixing and water washing type tail gas treatment system according to claim 2, characterized in that: A water net (62) evenly covering the ventilation cross-section is formed in the cooling interval (61). The water net (62) is composed of uniformly dispersed mist droplets. The water net (62) can cool the water vapor in the mixed tail gas to form flowing water mist mixed with the tail gas. The flowing water mist can absorb and dissolve the gas products easily soluble in water in the tail gas together with the water net (62). The flowing water mist dissolved with gas products forms the mixed tail gas in a white fog state.

6. The vapor mixing and water washing type tail gas treatment system according to claim 5, wherein: The water net (62) is composed of the overlapping of two groups of conical water mist (621) sprayed horizontally. Each group includes several conical water mist (621) and is arranged along the length direction of the ventilation cross-section. And there is an overlap in the edge area of two adjacent conical water mist (621). The two groups of conical water mist (621) are parallel to each other in the ventilation direction. And in the perspective of the ventilation cross-section, multiple conical water mist (621) of the two are arranged in a staggered manner in their own arrangement directions.

7. The vapor mixing and water washing type tail gas treatment system according to claim 6, characterized in that: A water baffle (8) is arranged above the cooling channel (6). The water baffle (8) is provided with an upward ventilation opening on the exhaust gas passing-through side of the water network (62); a gas distribution grid plate (9) is arranged at a distance above the water baffle (8).

8. The vapor mixing and water washing type tail gas treatment system according to claim 5, characterized in that: A high-density aerosol area is formed at the connection port of the upper part of the convection chamber (7) and the lower end of the spray tower (3), which can form an inhibitory force on the upward diffusion trend of the mixed exhaust gas in the white mist state.

9. The vapor mixing and water washing type tail gas treatment system according to claim 8, characterized in that: A water collecting tank (10) is arranged at the lower part of the water washing chamber (1), which can collect the water falling in the water washing chamber (1) and the spray tower (3), and can supply water to the plurality of water networks (62) in a circulating manner by pumping through a water pump; The water collecting tank (10) is provided with a substance concentration detection sensor and a water level monitoring sensor, and both are electrically connected to the opening and closing control module of the drainage pump through a controller.

10. A vapor mixing and water washing type tail gas treatment system according to claim 9, characterized in that: A plurality of layers of spray heads (31) arranged longitudinally are arranged in the spray tower (3), and a packing area is arranged below each layer of the spray heads (31). The spray water can uniformly pass through the packing area under the action of gravity and uniformly drip at the lower port of the spray tower (3) to form the longitudinal water spraying area in the convection chamber (7).

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