Hazardous waste incineration wet-process deacidification system

Abstract

The invention provides a hazardous waste incineration wet-process deacidification system, and belongs to the technical field of hazardous waste incineration, and the hazardous waste incineration wet-process deacidification system specifically comprises the steps that a first-stage tower is used for washing and purifying flue gas to be treated, and the purified flue gas is discharged from the top of the first-stage tower; the secondary tower is used for carrying out secondary washing purification on the flue gas treated by the primary tower, and the purified gas is discharged from the top of the secondary tower; the demister is used for demisting the flue gas subjected to secondary washing and purification and discharging the demisted flue gas into the atmosphere, the lower sections of the primary tower and the secondary tower are respectively provided with a circulating pool and a heat exchange device, the heat exchange devices are arranged in the circulating pools and are used for recovering part of heat in circulating liquid in the circulating pools, and an inlet pipeline of the circulating pump station is also provided with a medicament adding regulating valve. The pH value of circulating liquid is controlled, the water discharge amount is controlled through the salt concentration, and the aeration device prevents sediment and scaling from blocking a pipeline system and a nozzle. By means of the treatment scheme, heat energy of the system can be recycled, and meanwhile the moisture content in discharged flue gas and the water consumption of the system can be reduced on the basis that stable operation of the system is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of hazardous waste incineration, and in particular to a hazardous waste incineration wet deacidification system. Background Art

[0002] In the hazardous waste incineration industry, the commonly used flue gas deacidification systems are equipped with wet deacidification systems to adapt to the changing materials and working conditions.

[0003] However, the wet deacidification system has the following disadvantages: the temperature of the discharged saturated wet flue gas is about 70°C, and the temperature of the discharged wastewater is about 67°C, which causes a large amount of heat energy waste, and the chimney smoke plume tailing phenomenon is serious, affecting the environmental appearance; in order to ensure that the flue gas meets the emission standards, the secondary tower usually controls the pH to be higher and the salt concentration to be lower, resulting in waste of reagents, increased water consumption, and increased drainage; the pipes and nozzles are prone to scaling, affecting long-term operation, requiring manual intervention, and affecting production. Summary of the invention

[0004] Therefore, in order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a wet deacidification system for hazardous waste incineration, which can not only recover system heat energy, reduce chimney plume, and improve the surrounding environment, but also reduce system water consumption, save chemicals, and solve the scaling problem of deacidification system pipes and nozzles on the basis of achieving stable system operation.

[0005] In order to achieve the above object, the present invention provides a hazardous waste incineration wet deacidification system, comprising:

[0006] A first-stage tower, wherein a high-temperature flue gas inlet is provided in the middle section of the first-stage tower, and the first-stage tower washes and purifies the high-temperature flue gas to be treated, and the purified flue gas is discharged from the top of the first-stage tower;

[0007] A secondary tower, wherein the middle section of the secondary tower is provided with an inlet for the flue gas purified by the primary tower, and the secondary tower performs secondary washing and purification on the flue gas treated by the primary tower, and the purified flue gas is discharged from the top of the secondary tower;

[0008] The demister is arranged at the top of the secondary tower to demister the flue gas after the secondary washing and purification and then discharge it into the atmosphere.

[0009] The lower sections of the primary tower and the secondary tower are both provided with a circulation pool and a heat exchange device, the circulation pool is connected to a circulation pump station outside the tower, and the upper sections of the primary tower and the secondary tower are both provided with a washing device.

[0010] The circulating liquid enters the washing device through the circulating pump station to wash and purify the flue gas, and the washed circulating liquid falls back into the circulating pool;

[0011] The heat exchange device is arranged in the circulation pool and is used to recover part of the heat in the circulating liquid in the circulation pool.

[0012] The outlet of the circulation pool is connected to the inlet pipeline of the circulation pump station. The inlet pipeline of the circulation pump station is also provided with a reagent dosing pipeline. A reagent dosing regulating valve is provided upstream of the pipeline. The pH value of the circulation liquid is controlled by the reagent dosing regulating valve to ensure that the flue gas meets the emission standards.

[0013] A salt concentration detector is also provided at the inlet pipe of the circulation pump station to control the drainage of the circulation pool according to the salt concentration.

[0014] An aeration device is provided at the bottom of the circulation pool, and the aeration device is used to oxidize sulfite into sulfate to prevent precipitation and scaling from clogging the pipeline system and the nozzle.

[0015] In one of the embodiments, a pH meter and a salt concentration detector are provided at the inlet pipe of the circulation pump, and the reagent dosing regulating valve is provided between the salt concentration detector and the circulation pump station;

[0016] The liquid level of the circulation pool is monitored by a liquid level meter, the liquid level of the primary tower circulation pool is controlled by draining the secondary tower, and the liquid level of the secondary tower circulation pool is controlled by flushing the secondary tower demister to maintain normal operation of the system;

[0017] The inlet of the heat exchange device is provided with a regulating valve, and the outlet is provided with a thermometer;

[0018] The circulation pool is provided with an automatic drain valve;

[0019] Temperature and pressure online detection instruments are provided on the inlet and outlet flues of the first-stage tower and the second-stage tower.

[0020] In one of the embodiments, a regulating valve is provided at the low-temperature water inlet of the heat exchange device.

[0021] In one of the embodiments, the circulation pool of the primary tower is connected to the circulation pump station of the secondary tower, and the deacidification wastewater of the secondary tower is discharged into the primary tower for reuse.

[0022] In one embodiment, the pH value of the circulating liquid of the first tower is controlled to be in the range of 5-7 by a reagent dosing regulating valve; and the pH value of the circulating liquid of the second tower is controlled to be in the range of 6-8 by a reagent dosing regulating valve.

[0023] In one of the embodiments, the drainage of the secondary tower is controlled by the liquid level of the primary tower, and the liquid level of the secondary tower is controlled by the demister flushing water valve.

[0024] In one embodiment, the reagent added by the reagent adding regulating valve is liquid alkali with a concentration of about 30%.

[0025] Compared with the prior art, the advantages of the present invention are:

[0026] 1. Since an aeration device is installed at the bottom of the circulation pool, sulfite is oxidized into sulfate, which prevents precipitation and scaling from clogging the pipeline system and nozzles, which is conducive to the long-term operation of the system;

[0027] 2. The heat exchange device reduces the temperature of the circulating fluid and indirectly reduces the temperature of the flue gas, thereby reducing the moisture content in the flue gas, weakening the chimney plume, and improving the surrounding environment; the heat exchange device reduces the amount of water in the flue gas, and the water is discharged from the secondary tower into the primary tower for reuse, reducing the amount of water discharged and also reducing the water consumption of the system;

[0028] 3. The primary tower and the secondary tower are independently controlled. The secondary tower ensures that the flue gas meets the emission standards, controls the pH value to be higher and the salt concentration to be lower. The wastewater from the secondary tower is discharged into the primary tower for reuse, which optimizes the removal efficiency and reduces the dosage of reagents. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 is a schematic structural diagram of a hazardous waste incineration wet deacidification system in an embodiment of the present invention,

[0031] Among them, 1 is a first-stage tower, 2 is a first circulation pool, 3 is a first heat exchange device, 4 is a first aeration device, 5 is a first washing device, 6 is a first flue gas thermometer and pressure gauge, 7 is a first circulation pump station, 8 is a first pH meter and salt concentration detection instrument, 9 is a first liquid level meter, 10 is a first reagent dosing regulating valve, 11 is a first aeration control valve, 12 is a first heat exchange device inlet regulating valve, 13 is a first heat exchange device outlet thermometer, 14 is a first sewage valve, 15 is a second-stage tower, 16 is a second circulation pool, 17 is a second heat exchange device , 18 is the second aeration device, 19 is the second washing device, 20 is the demister, 21 is the second circulation pump station, 22 is the second pH meter and salt concentration detection instrument, 23 is the second liquid level meter, 24 is the second reagent addition regulating valve, 25 is the second aeration control valve, 26 is the second heat exchange device inlet regulating valve, 27 is the second heat exchange device outlet thermometer, 28 is the second sewage valve, 29 is the demister flushing valve, 30 is the first tower circulation pool water supply valve, 31 is the first flue gas thermometer and pressure gauge, 32 is the second flue gas thermometer and pressure gauge. DETAILED DESCRIPTION

[0032] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0033] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0034] It should be noted that various aspects of the embodiments within the scope of protection of the present invention are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspect described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0035] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0036] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects described may be practiced without these specific details.

[0037] like Figure 1 As shown, an embodiment of the present application provides a hazardous waste incineration wet deacidification system, including a primary tower 1, a secondary tower 15, and a demister 20 arranged in the secondary tower 15.

[0038] The middle section of the first-stage tower 1 is provided with an inlet for high-temperature flue gas. The first-stage tower washes and purifies the high-temperature flue gas to be treated, and the purified high-temperature flue gas is discharged from the top of the first-stage tower.

[0039] The middle section of the secondary tower 15 is provided with an inlet for the flue gas purified by the primary tower 1. The secondary tower performs secondary washing and purification on the flue gas treated by the primary tower, and the purified flue gas is discharged from the top of the secondary tower.

[0040] The demister 20 is disposed at the top of the secondary tower 15 to demister the high temperature flue gas purified by secondary washing before discharging it into the atmosphere.

[0041] The lower sections of the primary tower 1 and the secondary tower 15 are both provided with a circulation pool and a heat exchange device, the circulation pool is connected to the circulation pump station outside the tower, and the upper sections of the primary tower and the secondary tower are both provided with a washing device. In order to improve the deacidification efficiency, the circulating liquid of the secondary tower is weakly alkaline; the circulating liquid in the primary tower is weakly acidic, and the drainage of the secondary tower is sent to the primary tower for reuse, avoiding the waste of liquid alkali when the secondary tower is directly drained.

[0042] The circulating liquid enters the washing device through the circulating pump station to wash and purify the flue gas, and the circulating liquid after washing falls back into the circulating pool.

[0043] The heat exchange device is arranged in the circulation pool to recover part of the heat in the circulating fluid in the circulation pool. The recovered heat can be used for heating other devices or systems.

[0044] The outlet of the circulation pool is connected to the inlet pipeline of the circulation pump station. A reagent dosing pipeline is also provided at the inlet pipeline of the circulation pump station. A reagent dosing regulating valve is provided upstream of the pipeline. The pH value of the circulating liquid is controlled by the reagent dosing regulating valve to ensure that the flue gas meets the emission standards.

[0045] A salt concentration detector is also installed at the inlet pipe of the circulating pump station to control the discharge volume according to the salt concentration.

[0046] An aeration device is installed at the bottom of the circulation pool to oxidize sulfite into sulfate to prevent precipitation and scaling from clogging the pipeline system and nozzles. The aeration control valve is installed on the inlet pipeline of the aeration device, which is opened when aeration is needed and closed when it is not needed; for example, when there is less sulfur-containing material, aeration is not needed and it can be closed to save energy; it is opened when large-scale discharge and replenishment are required to reduce the sedimentation at the bottom of the tower.

[0047] In the above-mentioned device, an aeration device is arranged at the bottom of the circulation pool to oxidize sulfite into sulfate, so as to avoid precipitation and scaling that clogs the pipeline system and nozzles, which is beneficial to the long-term operation of the system; and the heat exchange device reduces the temperature of the circulating liquid, indirectly reduces the temperature of the flue gas, thereby reducing the moisture content in the exhaust flue gas, weakening the chimney plume, and improving the surrounding environment; the heat exchange device reduces the amount of water in the exhaust flue gas, and discharges water from the secondary tower into the primary tower for reuse to reduce the drainage volume, and also reduces the water consumption of the system; in addition, the primary tower and the secondary tower are independently controlled, and the secondary tower ensures that the flue gas meets the emission standards, controls the pH value to be higher and the salt concentration to be lower, and the wastewater from the secondary tower is discharged into the primary tower for reuse, thereby optimizing the removal efficiency and reducing the amount of reagents used.

[0048] In one embodiment, a pH meter and a salt concentration detector are provided at the inlet pipe of the circulation pump, and a reagent dosing regulating valve is provided between the pH meter, the salt concentration detector and the circulation pump station;

[0049] The liquid level of the circulation pool is monitored by a liquid level meter. The first tower controls the liquid level of the circulation pool by discharging the drainage water of the circulation pool of the second tower into the valve of the circulation pool of the first tower. The second tower controls the liquid level of the circulation pool of the second tower by the defogger flushing valve to maintain the normal operation of the system.

[0050] A regulating valve is provided at the inlet of the heat exchange device and a thermometer is provided at the outlet;

[0051] The circulating pool is equipped with an automatic drain valve;

[0052] Temperature and pressure online detection instruments are installed on the inlet and outlet flues of the first-level tower and the second-level tower.

[0053] In one of the embodiments, a regulating valve is provided at the low-temperature water inlet of the heat exchange device.

[0054] In one embodiment, the circulation pool of the secondary tower is connected to the circulation pump station of the primary tower, and the deacidification wastewater of the secondary tower is discharged into the primary tower for reuse.

[0055] In one embodiment, the pH value of the circulating liquid of the first tower is controlled to be in the range of 5-7 by the reagent dosing regulating valve; the pH value of the circulating liquid of the second tower is controlled to be in the range of 6-8 by the reagent dosing regulating valve.

[0056] In one of the embodiments, the drainage of the secondary tower is controlled by the liquid level of the primary tower, and the liquid level of the secondary tower is controlled by the demister flushing water valve.

[0057] In one embodiment, the reagent added by the reagent adding regulating valve is liquid caustic soda with a concentration of about 30%.

[0058] Embodiment 1

[0059] like Figure 1 As shown, an embodiment of the present application provides a hazardous waste incineration wet deacidification system, including a primary tower 1, a secondary tower 15, and a demister 20 arranged in the secondary tower 15.

[0060] A first circulation pool 2, a first heat exchange device 3, a first aeration device 4 and a first washing device 5 are arranged in the primary tower 1.

[0061] The first circulation pump station 7 is connected to the first circulation pool 2 through a pipeline, the first washing device 5 is connected to the first circulation pump station 7 through a pipeline, a pH meter and a salt concentration detection instrument 8 and a reagent adding pipeline are arranged on the pipeline between the first circulation pool 2 and the first circulation pump station 7, a reagent adding regulating valve 10 is arranged upstream of the pipeline, an inlet regulating valve 12 and an outlet thermometer 13 are arranged on the first heat exchange device 3, a liquid level meter 9 is arranged on the first circulation pool 2, and a first sewage valve 14 is arranged at the bottom of the first circulation pool 2.

[0062] The circulating liquid in the first circulation pool 2 enters the first washing device 5 through the first circulation pump station 7 to wash and purify the flue gas once, and the washed circulating liquid falls back into the first circulation pool 2. The pH meter and salt concentration detection instrument 8 control the opening of the reagent dosing valve 10 and the opening of the first sewage valve 14, and the outlet thermometer 13 of the first heat exchange device 3 controls the opening of the inlet regulating valve 12.

[0063] A second circulation pool 16 , a second heat exchange device 17 , a second aeration device 18 and a second washing device 19 are provided in the secondary tower 15 .

[0064] The second circulation pump station 21 is connected to the second circulation pool 16 through a pipeline, the second washing device 19 is connected to the second circulation pump station 21 through a pipeline, a pH meter and a salt concentration detection instrument 22 and a reagent adding pipeline are arranged on the pipeline between the second circulation pool 16 and the second circulation pump station 21, a reagent adding regulating valve 24 is arranged upstream of the pipeline, the second heat exchange device 17 is provided with an inlet regulating valve 26 and an outlet thermometer 27, the second circulation pool 16 is provided with a liquid level meter 23, the demister 20 is provided with a flushing water valve 27, and a second sewage valve 28 is arranged at the bottom of the second circulation pool 16.

[0065] The circulating liquid in the second circulation pool 16 enters the second washing device 19 through the second circulation pump station 21, performs secondary washing and purification on the flue gas, and the washed circulating liquid falls back into the second circulation pool 16. The pH meter and salt concentration detection instrument 22 include a pH meter and a salt concentration detection instrument connected in series, wherein the opening of the reagent dosing valve 24 is controlled according to the acidity and alkalinity detected by the pH meter, and the opening of the second sewage valve 28 is controlled according to the concentration detected by the salt concentration detection instrument. The outlet thermometer 27 of the second heat exchange device 17 controls the opening of the inlet regulating valve 26.

[0066] A drain valve 30 is provided on the pipeline between the second circulation pump station 21 and the second washing device 19 to drain water into the first circulation pool 2. A thermometer and a pressure gauge 6 are provided on the inlet flue of the first tower 1. A thermometer and a pressure gauge 31 are provided on the flue between the first tower 1 and the second tower 15. A second thermometer and a pressure gauge 32 are provided on the outlet flue of the second tower 15. The liquid level meter 9 controls the opening of the drain valve 30.

[0067] The drainage of the secondary tower is controlled by the liquid level of the primary tower, and the liquid level of the secondary tower is controlled by the demister flushing water valve. The control is simple and is conducive to the stable operation of the control system.

[0068] The drainage of the secondary tower 15 is controlled by the liquid level of the primary tower 1. When the liquid level of the primary tower 1 is low, the opening of the water replenishment valve 30 of the primary tower circulation pool is controlled to make the liquid level of the primary tower reach the normal level; when the liquid level of the primary tower is high and the salt concentration of the secondary tower is also high, the primary tower is drained first to lower the liquid level, and then the secondary tower continues to drain to the primary tower. If it is too late, the demister 20 can be opened for flushing to allow the secondary tower to overflow, thereby reducing the salt concentration of the secondary tower.

[0069] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed in the present application should be covered within the protection scope of the present application.

Claims

1. A hazardous waste incineration wet deacidification system, characterized in that: include: A first-stage tower, wherein a high-temperature flue gas inlet is provided in the middle section of the first-stage tower, and the first-stage tower washes and purifies the high-temperature flue gas to be treated, and the purified high-temperature flue gas is discharged from the top of the first-stage tower; A secondary tower, wherein the middle section of the secondary tower is provided with an inlet for the flue gas purified by the primary tower, and the secondary tower performs secondary washing and purification on the flue gas treated by the primary tower, and the purified flue gas is discharged from the top of the secondary tower; A demister is arranged at the top of the secondary tower to demister the flue gas purified by the secondary scrubbing and then discharge it into the atmosphere; Wherein, the lower sections of the primary tower and the secondary tower are both provided with a circulation pool and a heat exchange device, the circulation pool is connected to a circulation pump station outside the tower, and the upper sections of the primary tower and the secondary tower are both provided with a washing device; The circulating liquid enters the washing device through the circulating pump station to wash and purify the high-temperature flue gas, and the washed circulating liquid falls back into the circulating pool; The heat exchange device is arranged in the circulation pool and is used to recover part of the heat in the circulation liquid in the circulation pool; The outlet of the circulation pool is connected to the inlet pipeline of the circulation pump station. A reagent dosing regulating valve is also provided at the inlet pipeline of the circulation pump station. The pH value of the circulation liquid is controlled by the reagent dosing regulating valve to ensure that the flue gas meets the emission standards. A salt concentration detector is also provided at the inlet pipe of the circulation pump station to control the drainage of the circulation pool according to the salt concentration; An aeration device is provided at the bottom of the circulation pool, and the aeration device is used to oxidize sulfite into sulfate to prevent precipitation and scaling from clogging the pipeline system and the nozzle.

2. The hazardous waste incineration wet deacidification system according to claim 1, characterized in that: A pH meter and a salt concentration detector are arranged at the inlet pipe of the circulation pump, and the reagent dosing regulating valve is arranged between the salt concentration detector and the circulation pump station; Monitoring the liquid level of the circulation pool by means of a liquid level meter; The inlet of the heat exchange device is provided with a regulating valve, and the outlet is provided with a thermometer; The circulation pool is provided with an automatic drain valve; Temperature and pressure online detection instruments are provided on the inlet and outlet flues of the first-stage tower and the second-stage tower.

3. The hazardous waste incineration wet deacidification system according to claim 1, characterized in that: A regulating valve is provided at the low-temperature water inlet of the heat exchange device.

4. The hazardous waste incineration wet deacidification system according to claim 1, characterized in that: The circulation pool of the primary tower is connected to the circulation pump station of the secondary tower, and the deacidification wastewater of the secondary tower is discharged into the primary tower for reuse.

5. The hazardous waste incineration wet deacidification system according to claim 1, characterized in that: The pH value of the circulating liquid of the first tower is controlled to be in the range of 5-7 by a reagent dosing regulating valve; the pH value of the circulating liquid of the second tower is controlled to be in the range of 6-8 by a reagent dosing regulating valve.

6. The hazardous waste incineration wet deacidification system according to claim 1, characterized in that: The drainage of the secondary tower is controlled by the liquid level of the primary tower, and the liquid level of the secondary tower is controlled by the demister flushing water valve.

7. The hazardous waste incineration wet deacidification system according to claim 1, characterized in that: The reagent dosing regulating valve controls the dosing of the reagent to be liquid caustic soda with a concentration of about 30%.

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