Deacidification system with alkali reuse function

Abstract

This utility model relates to a deacidification system with alkali reuse function, including a deacidification tower. The internal space of the deacidification tower, from top to bottom, includes a flue gas outlet layer, a spray layer, a flue gas inlet layer, and a collection tank. It also includes a sedimentation tank and a liquid collection tank. The spray layer includes an upper spray layer and a lower spray layer. The upper spray layer is equipped with an upper spray mechanism that sprays high-concentration alkali solution from the alkali source. The lower spray layer is equipped with a lower spray mechanism. A circulation pipe is provided between the collection tank and the sedimentation tank, and the circulation pipe is equipped with a circulation pump. The sedimentation tank and the liquid collection tank are arranged side by side, and a transfer pipe is provided between the sedimentation tank and the liquid collection tank, and the transfer pipe is equipped with a transfer pump. A recovery pipe is provided between the liquid collection tank and the lower spray mechanism, and the recovery pipe is equipped with a recovery pump and a filter. The lower spray mechanism sprays low-concentration alkali solution. By adopting the above scheme, this utility model provides a deacidification system that fully utilizes alkali solution and has an alkali reuse function.

Description

Technical Field

[0001] This utility model relates to the field of waste incineration equipment, specifically to a deacidification system with alkali reuse function. Background Technology

[0002] The flue gas produced by waste incineration contains a variety of high concentrations of acidic pollutants. If it is emitted directly without treatment, it will cause catastrophic environmental pollution. Therefore, during the waste incineration process, it is often necessary to equip the flue gas with a deacidification system to treat the acidic pollutants in the flue gas.

[0003] Existing deacidification systems generally include a deacidification tower. The internal space of the deacidification tower, from top to bottom, includes a flue gas outlet layer, a spray layer, a flue gas inlet layer, and a collection tank. The flue gas generated by boiler combustion enters the flue gas inlet layer from the side. After being sprayed with alkaline solution by the spray layer, the alkaline solution leaves the deacidification tower through the flue gas outlet layer, while the alkaline solution sprayed by the spray layer falls into the collection tank.

[0004] To ensure the deacidification effect, high-concentration alkaline solution is often sprayed. When sprayed, the high-concentration alkaline solution produces large droplets, which can adsorb the trace amounts of acidic gases remaining in the surrounding flue gas, making the deacidification of the flue gas more complete. However, it is easy to produce "surface passivation" (a solid salt shell forms on the surface during deacidification to prevent the internal alkaline solution from continuing to deacidify), which leads to a decrease in the utilization rate of the alkaline solution and thus waste of the alkaline solution. Utility Model Content

[0005] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a deacidification system that makes full use of alkaline solution and has the function of reusing alkaline solution.

[0006] To achieve the above objectives, this utility model provides the following technical solution: It includes a deacidification tower, the internal space of which, from top to bottom, includes a flue gas outlet layer, a spray layer, a flue gas inlet layer, and a collection tank. The flue gas inlet layer has a flue gas inlet on its side, and the flue gas outlet layer has a flue gas outlet on its side. It also includes a sedimentation tank and a liquid collection tank. The spray layer includes an upper spray layer and a lower spray layer. The upper spray layer is equipped with an upper spray mechanism connected to an alkali source and spraying high-concentration alkali solution from the alkali source. The lower spray layer is equipped with a lower spray mechanism. A connection is provided between the collection tank and the sedimentation tank. The system includes a circulation pipeline equipped with a circulation pump that transfers the low-concentration alkaline solution collected in the collection tank to the sedimentation tank. The sedimentation tank and the liquid collection tank are arranged side by side, and a transfer pipeline is provided between them. The transfer pipeline is equipped with a transfer pump that transfers the precipitated low-concentration alkaline solution from the sedimentation tank to the liquid collection tank. A recovery pipeline is provided between the liquid collection tank and the lower spraying mechanism. The recovery pipeline is equipped with a recovery pump that transfers the stored low-concentration alkaline solution from the liquid collection tank to the lower spraying mechanism and a filter that filters the low-concentration alkaline solution. The lower spraying mechanism sprays the low-concentration alkaline solution from the liquid collection tank.

[0007] By adopting the above technical solution, the upper spraying mechanism sprays the high-concentration alkaline solution from the alkaline source and completely adsorbs the acidic gases in the flue gas. The excess alkaline solution falls and is collected in the collection tank. Since most of the alkaline solution is consumed, the concentration is greatly reduced. Then, the circulation pump transfers the low-concentration alkaline solution and the solid substances generated during the deacidification process to the sedimentation tank for sedimentation through the circulation pipeline. Then, the transfer pump transfers the sedimented low-concentration alkaline solution to the liquid collection tank through the transfer pipeline. Finally, the recovery pump transfers the stored low-concentration alkaline solution to the lower spraying mechanism located below the upper spraying mechanism through the recovery pipeline, and the lower spraying mechanism sprays the low-concentration alkaline solution. The above system has the following advantages: ① The low-concentration alkaline solution collected in the collection tank is circulated to the lower spraying mechanism below the upper spraying mechanism for spraying high-concentration alkaline solution. This serves as a pre-spraying stage before the upper spraying mechanism. Because the low-concentration alkaline solution has a low concentration and carries a certain amount of heat, it can form fine droplets during spraying. These fine droplets can quickly and completely react with the nearby acidic gases, making full use of the unused alkaline solution in the large droplets sprayed by the upper spraying mechanism. The total amount of alkaline solution will not gradually accumulate in the collection tank, forming a virtuous cycle and improving the utilization rate of the alkaline solution; ② The upper and lower spraying mechanisms are combined... The combined multiple deacidification process optimizes the deacidification effect; ③ Since solid substances are generated during the deacidification process, the low-concentration alkaline solution is completely filtered out after sedimentation in the sedimentation tank and filtration in the filter, avoiding clogging of the lower spray mechanism. At the same time, the filter is mainly used to filter floating fine solid substances, and the sedimentation tank can effectively reduce its filtration burden and extend its service life; ④ A liquid collection tank is added between the sedimentation tank and the lower spray mechanism, which can balance the flow fluctuation, avoid intermittent spraying of the lower spray mechanism, and provide a mixing place for the low-concentration alkaline solution, making the concentration and temperature of the low-concentration alkaline solution sprayed by the lower spray mechanism more uniform.

[0008] The present invention is further configured such that: a flow-blocking layer is provided between the upper spray layer and the lower spray layer, and the flow-blocking layer is surrounded by a plurality of gas nozzles connected to an inert gas source and intermittently spraying inert gas toward the center.

[0009] By adopting the above technical solution and adding a flow-blocking layer, gas nozzles arranged in a ring around the flow-blocking layer intermittently spray gas, forming a gas barrier between the upper and lower spray layers. First, this reduces the rising rate of the flue gas, prolongs the contact time between the flue gas and the sprayed alkaline solution, and ensures the deacidification effect. Second, the impact generated by the gas can separate the solid salt shell on the surface of some large droplets from the large droplets, improving the utilization rate of the alkaline solution.

[0010] The present invention is further configured such that: an airflow distribution plate is provided between the lower spray layer and the flue gas inlet layer; the airflow distribution plate is provided with multiple diversion holes that evenly distribute the airflow through it vertically; and the airflow distribution plate is provided with a flow-guiding ramp along its edge that gradually decreases in height as it approaches the center.

[0011] By adopting the above technical solution, the flue gas entering from the side of the flue gas inlet layer tends to gather on one side. The airflow distribution plate makes the distribution of flue gas more uniform, thereby fully consuming the low-concentration alkaline solution sprayed by the lower spraying mechanism. At the same time, the distribution plate can also reduce the rising rate of flue gas, prolong the contact time between flue gas and sprayed alkaline solution, and ensure the deacidification effect. Secondly, the gathered alkaline solution can fully contact the flue gas when passing through the diversion hole, further optimizing the deacidification effect. In addition, in order to avoid the accumulation of gathered alkaline solution at the corner formed by the edge of the deacidification tower and the airflow distribution plate, a diversion ramp is added at the edge of the airflow distribution plate to guide the alkaline solution back to the diversion hole.

[0012] The present invention is further configured such that: a tower lifting support is provided below the deacidification tower to raise the bottom height; a connection port connected to the circulation pipeline is provided at the center of the bottom of the collection tank; and the bottom of the collection tank gradually decreases in height towards the connection port from the edge.

[0013] By adopting the above technical solution, when there is too much sediment at the bottom of the collection tank, it is necessary to stop the machine and open the deacidification tower to clean the sediment. This process will undoubtedly reduce the processing efficiency of the waste incineration equipment. Therefore, the bottom structure of the collection tank is adjusted to be funnel-shaped so that most of the sediment will gather towards the connection port and reach the sedimentation tank from the connection port-circulation pipeline. This reduces the number of times the sediment in the deacidification tower needs to be cleaned, thereby improving the processing efficiency of the waste incineration equipment and achieving the sealed transfer of sediment in the deacidification tower.

[0014] The present invention is further configured such that: a tank lifting support is provided below the sedimentation tank to raise the bottom height; a waste discharge port is provided at the center of the bottom of the sedimentation tank; and a waste discharge pipe is provided at the waste discharge port to discharge the sediment and alkaline solution from the bottom of the sedimentation tank.

[0015] By adopting the above technical solution, as the deacidification reaction proceeds, the liquid level in the sedimentation tank and the liquid collection tank will become higher and higher. Therefore, the bottom of the sedimentation tank is adjusted to be funnel-shaped so that the excess low concentration carries a large amount of sediment and is discharged in a unified manner through the waste discharge pipeline, ensuring the stable operation of the system.

[0016] The present invention is further configured such that: the liquid collection tank is equipped with a pH sensor for detecting the pH value of the alkaline solution and a liquid level sensor for detecting the liquid level height; and the liquid collection tank is equipped with a water supply pipe that is connected to a water source and replenishes water to the liquid collection tank.

[0017] By adopting the above technical solution, the pH value sensor and the liquid level sensor are used to monitor the pH value and liquid level of the liquid collection tank in real time, making the system control more intelligent. When the alkali utilization rate is insufficient and the pH value is too high, water can be added to the liquid collection tank through the water replenishment pipe to reduce the alkali concentration and ensure that the droplets formed during spraying are small.

[0018] The present invention is further provided with an insulation layer on the outside of the circulating pipeline, sedimentation tank, transfer pipeline, liquid extraction tank and recovery pipeline.

[0019] By adopting the above technical solution and adding an insulation layer, the heat loss of low-concentration alkaline solution during the recycling process is reduced, ensuring that the droplets formed during spraying are smaller. Attached Figure Description

[0020] Figure 1 This is a structural schematic diagram of a specific embodiment of the present utility model; Figure 2 for Figure 1 A magnified view of A in the middle. Detailed Implementation

[0021] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0022] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] like Figure 1 — Figure 2As shown, this utility model discloses a deacidification system with alkali reuse function, including a deacidification tower 1. The internal space of the deacidification tower 1 includes, from top to bottom, a flue gas outlet layer 11, a spray layer, a flue gas inlet layer 14, and a collection tank 15. The flue gas inlet layer 14 is provided with a flue gas inlet 141 on its side, and the flue gas outlet layer 11 is provided with a flue gas outlet 111 on its side. It also includes a sedimentation tank 3 and a liquid collection tank 4. The spray layer includes an upper spray layer 12 and a lower spray layer 13. The upper spray layer 12 is provided with an upper spray mechanism, which is connected to an alkali source and sprays high-concentration alkali from the alkali source. The upper spray mechanism includes an upper spray seat 121 fixed to the side wall of the deacidification tower 1, and the upper spray seat 121 is provided with a liquid inlet pipe 1 connected to the alkali source. 22. The upper spray seat 121 distributes the high-concentration alkaline solution to multiple upper spray pipes 123 located in the upper spray layer 12. Each upper spray pipe 123 is equipped with multiple upper alkaline solution nozzles 124. The lower spray layer 13 is equipped with a lower spray mechanism. A circulation pipe 2 is provided between the collection tank 15 and the sedimentation tank 3. The circulation pipe 2 is equipped with a circulation pump 21 that transfers the low-concentration alkaline solution collected in the collection tank 15 to the sedimentation tank 3. The rear end of the circulation pipe 2 is above the liquid surface of the sedimentation tank 3. The sedimentation tank 3 and the liquid extraction tank 4 are arranged side by side. A transfer pipe 5 is provided between the sedimentation tank 3 and the liquid extraction tank 4. The transfer pipe 5 is located above the sedimentation tank 3 and the liquid extraction tank 4. The front end of the transfer pipe 5 is below the liquid surface near the top of the sedimentation tank 3, and the rear end is below the liquid surface near the top of the sedimentation tank 3. Above the liquid level in the liquid collection tank 4, a transfer pipe 5 is equipped with a transfer pump 51 that transfers the precipitated low-concentration alkaline solution from the sedimentation tank 3 to the liquid collection tank 4. A recovery pipe 6 is provided between the liquid collection tank 4 and the lower spraying mechanism. The recovery pipe 6 is equipped with a recovery pump 61 that transfers the stored low-concentration alkaline solution from the liquid collection tank 4 to the lower spraying mechanism and a filter 62 that filters the low-concentration alkaline solution. The front end of the recovery pipe 6 extends to a position near the bottom of the liquid collection tank 4. The lower spraying mechanism sprays the low-concentration alkaline solution from the liquid collection tank 4. The lower spraying mechanism includes a lower spray seat 131 fixed to the side wall of the deacidification tower 1. The lower spray seat 131 is connected to the recovery pipe 6. The lower spray seat 131 distributes the low-concentration alkaline solution to multiple lower spray pipes located in the lower spraying layer 13. Each of the lower spray pipes 132 is equipped with multiple lower alkali spray nozzles 133. The upper spray mechanism sprays the high-concentration alkali solution from the alkali source to completely adsorb the acidic gases in the flue gas. The excess alkali solution falls and is collected by the collection tank 15. Since most of the alkali solution is consumed, the concentration is greatly reduced. Then, the circulation pump 21 transfers the low-concentration alkali solution and the solids generated during the deacidification process to the sedimentation tank 3 for sedimentation through the circulation pipe 2. Then, the transfer pump 51 transfers the sedimented low-concentration alkali solution to the liquid collection tank 4 through the transfer pipe 5. Finally, the recovery pump 61 transfers the stored low-concentration alkali solution to the lower spray mechanism located below the upper spray mechanism through the recovery pipe 6, and the lower spray mechanism sprays the low-concentration alkali solution.The above system has the following advantages: ① The low-concentration alkaline solution collected in collection tank 15 is circulated to the lower spraying mechanism below the upper spraying mechanism for spraying high-concentration alkaline solution, serving as a pre-spraying stage before the upper spraying mechanism. Because the low-concentration alkaline solution has a low concentration and carries a certain amount of heat, it can form fine droplets during spraying. These fine droplets can quickly and completely react with the nearby acidic gases, fully utilizing the unused alkaline solution in the large droplets sprayed by the upper spraying mechanism. The total amount of alkaline solution will not gradually accumulate in collection tank 15, forming a virtuous cycle and improving the utilization rate of the alkaline solution; ② The combination of the upper and lower spraying mechanisms forms a... The process involves multiple deacidification steps to optimize the deacidification effect; ③ Since solid substances are generated during the deacidification process, the low-concentration alkaline solution is completely filtered out after sedimentation in the sedimentation tank 3 and filtration in the filter 62, avoiding clogging of the lower spray mechanism. At the same time, the filter 62 is mainly used to filter floating fine solid substances, and the sedimentation tank 3 can effectively reduce its filtration burden and extend its service life; ④ A liquid collection tank 4 is added between the sedimentation tank 3 and the lower spray mechanism, which can balance the flow fluctuation, avoid intermittent spraying of the lower spray mechanism, and provide a mixing place for the low-concentration alkaline solution, making the concentration and temperature of the low-concentration alkaline solution sprayed by the lower spray mechanism more uniform.

[0024] A flow-blocking layer 16 is provided between the upper spray layer 12 and the lower spray layer 13. The flow-blocking layer 16 is surrounded by multiple gas nozzles 161 connected to an inert gas source and intermittently spraying inert gas toward the center. A gas distribution seat 162 is arranged around the outside of the deacidification tower 1. The gas distribution seat 162 is provided with an inlet pipe 163 connected to the inert gas source. The gas distribution seat 162 distributes the inert gas to each gas nozzle 161. The addition of the flow-blocking layer 16 and the intermittent jetting of the gas nozzles arranged in a ring on the flow-blocking layer 16 form a gas barrier between the upper spray layer 12 and the lower spray layer 13. First, it can reduce the rising rate of the flue gas and prolong the contact time between the flue gas and the sprayed alkaline solution, ensuring the deacidification effect. Second, the impact generated by the gas can separate the solid salt shell on the surface of some large droplets from the large droplets, improving the utilization rate of the alkaline solution.

[0025] An airflow equalization disk 17 is provided between the lower spray layer 13 and the flue gas inlet layer 14. The airflow equalization disk 17 is vertically perforated with multiple diversion holes 171 that evenly distribute the airflow. The airflow equalization disk 17 is provided with a guide ramp 172 along its edge, which gradually decreases in height as it approaches the center. Flue gas entering from the side of the flue gas inlet layer 14 tends to gather on one side. The airflow equalization disk 17 makes the distribution of flue gas more uniform, thereby fully consuming the low-concentration alkaline solution sprayed by the lower spray mechanism. At the same time, the equalization disk can also reduce the rising rate of flue gas, prolong the contact time between flue gas and sprayed alkaline solution, and ensure the deacidification effect. Secondly, the gathered alkaline solution can fully contact the flue gas when passing through the diversion holes 171, further optimizing the deacidification effect. In addition, in order to avoid the accumulation of gathered alkaline solution at the corner formed by the edge of the deacidification tower 1 and the airflow equalization disk 17, a guide ramp 172 is added to the edge of the airflow equalization disk 17 to guide the alkaline solution back to the diversion holes 171.

[0026] A tower lifting support 18 is installed below the deacidification tower 1 to raise the bottom height. A connection port 151 connected to the circulation pipe 2 is set at the center of the bottom of the collection tank 15. The bottom of the collection tank 15 gradually decreases in height towards the connection port 151 from the edge. When there is too much sediment at the bottom of the collection tank 15, it is necessary to stop the machine and open the deacidification tower 1 to clean the sediment. This process will undoubtedly reduce the processing efficiency of the waste incineration equipment. Therefore, the bottom structure of the collection tank 15 is adjusted to a funnel shape so that most of the sediment will gather towards the connection port 151 and reach the sedimentation tank 3 from the connection port 151 through the circulation pipe 2. This reduces the number of sediment cleaning times of the deacidification tower 1 and improves the processing efficiency of the waste incineration equipment, realizing the sealed transfer of sediment in the deacidification tower 1.

[0027] A tank lifting support 31 is installed below the sedimentation tank 3 to raise the bottom height. A waste discharge port 32 is set at the center of the bottom of the sedimentation tank 3. The waste discharge port 32 is equipped with a waste discharge pipe 33 to discharge the sediment and alkaline solution at the bottom of the sedimentation tank 3. As the deacidification reaction proceeds, the liquid level in the sedimentation tank 3 and the liquid taking tank 4 will become higher and higher. Therefore, the bottom of the sedimentation tank 3 is adjusted to be funnel-shaped so that the excess low concentration carrying a large amount of sediment is discharged uniformly through the waste discharge pipe 33 to ensure the stable operation of the system.

[0028] The liquid collection tank 4 is equipped with a pH sensor 41 for detecting the pH value of the alkali solution and a liquid level sensor 42 for detecting the liquid level. The liquid collection tank 4 is also equipped with a water supply pipe 43 that connects to a water source and replenishes water to the liquid collection tank 4. The pH sensor 41 and the liquid level sensor 42 work together to monitor the pH value and liquid level of the liquid collection tank 4 in real time, making the system control more intelligent. When the alkali utilization rate is insufficient and the pH value is too high, water can be added to the liquid collection tank 4 through the water supply pipe 43 to reduce the alkali concentration and ensure that the droplets formed during spraying are small.

[0029] The outer sides of the circulation pipe 2, sedimentation tank 3, transfer pipe 5, liquid collection tank 4, and recovery pipe 6 are all equipped with insulation layers. The addition of insulation layers reduces heat loss of low-concentration alkaline solution during the recycling process and ensures that the droplets formed during spraying are small. Existing commercially available insulation materials can be used for the insulation layer, and rock wool is generally selected.

Claims

1. A deacidification system with alkali reuse function, comprising a deacidification tower, wherein the internal space of the deacidification tower comprises, from top to bottom, a flue gas outlet layer, a spray layer, a flue gas inlet layer, and a collection tank, wherein a flue gas inlet is provided on the side of the flue gas inlet layer, and a flue gas outlet is provided on the side of the flue gas outlet layer, characterized in that: It also includes a sedimentation tank and a liquid collection tank. The spray layer includes an upper spray layer and a lower spray layer. The upper spray layer is equipped with an upper spray mechanism, which is connected to the alkali source and sprays the high-concentration alkali from the alkali source. The lower spray layer is equipped with a lower spray mechanism. A circulation pipe is provided between the collection tank and the sedimentation tank. The circulation pipe is equipped with a circulation pump that transfers the low-concentration alkali collected in the collection tank to the sedimentation tank. The sedimentation tank and the liquid collection tank are arranged side by side. A transfer pipe is provided between the sedimentation tank and the liquid collection tank. The transfer pipe is equipped with a transfer pump that transfers the precipitated low-concentration alkali from the sedimentation tank to the liquid collection tank. A recovery pipe is provided between the liquid collection tank and the lower spray mechanism. The recovery pipe is equipped with a recovery pump that transfers the stored low-concentration alkali from the liquid collection tank to the lower spray mechanism and a filter that filters the low-concentration alkali. The lower spray mechanism sprays the low-concentration alkali from the liquid collection tank.

2. The deacidification system with alkali reuse function according to claim 1, characterized in that: A flow-blocking layer is provided between the upper and lower spray layers, and multiple gas nozzles connected to an inert gas source are arranged around the flow-blocking layer to intermittently spray inert gas toward the center.

3. The deacidification system with alkali solution reuse function according to claim 1, characterized in that: An airflow distribution plate is provided between the lower spray layer and the flue gas inlet layer. The airflow distribution plate is provided with multiple diversion holes that evenly distribute the airflow through it vertically. The airflow distribution plate is provided with a flow ramp along its edge that gradually decreases in height as it approaches the center.

4. The deacidification system with alkali solution reuse function according to claim 1, characterized in that: The deacidification tower is equipped with a tower lifting support to raise the bottom height. The bottom of the collection tank is provided with a connection port connected to the circulation pipeline at the center. The bottom of the collection tank gradually decreases in height towards the connection port from the edge.

5. The deacidification system with alkali reuse function according to claim 1, characterized in that: The sedimentation tank is equipped with a tank lifting support at the bottom to raise the bottom height. A waste discharge port is provided at the center of the bottom of the sedimentation tank, and a waste discharge pipe is provided at the waste discharge port to discharge the sediment and alkaline solution from the bottom of the sedimentation tank.

6. The deacidification system with alkali reuse function according to claim 1, characterized in that: The liquid collection tank is equipped with a pH sensor to detect the pH value of the alkali solution and a liquid level sensor to detect the liquid level height. The liquid collection tank is also equipped with a water supply pipe that connects to a water source and replenishes the liquid collection tank with water.

7. The deacidification system with alkali reuse function according to claim 1, characterized in that: The circulating pipeline, sedimentation tank, transfer pipeline, liquid extraction tank, and recovery pipeline are all equipped with an insulation layer on the outside.

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