Desulfurization wastewater discharge system and method

Abstract

The invention discloses a desulfurization wastewater discharge system and method, and relates to the technical field of desulfurization wastewater discharge, the desulfurization wastewater discharge system comprises a liquid inlet assembly, an evaporation assembly, a boiler, a reduction assembly and an evaporator, and the boiler is connected to the end of the reduction assembly through a first bypass; the reduction assembly is used for introducing boiler tail gas of waste heat reduced by the reduction assembly into the evaporator through a second pipeline; at least one group of introduction components; the dust removal assemblies are connected to the bottom of the evaporator. The device has the beneficial effects that waste water is directly evaporated to dryness by utilizing heat of boiler tail gas, solid particles generated by evaporation are captured by the dust remover and are discharged along with soot, no extra waste is generated, the moisture content of flue gas is increased by moisture entering the flue gas along with spray, the tail-end flue gas subjected to dust removal of the boiler is adopted as a concentration heat source, and the energy consumption is reduced. Other heat sources do not need to be consumed, and the purpose of treating waste with waste is achieved by heating and concentrating desulfurization waste water.

Description

Technical Field

[0001] The invention relates to the technical field of desulfurization wastewater discharge, and in particular to a desulfurization wastewater discharge system and method. Background Art

[0002] At present, the treatment method for desulfurization wastewater is generally to convert heavy metal pollutants in the wastewater into ammonium compounds through a series of chlorination reduction reactions, and then remove heavy metals and suspended solids through flocculation precipitation, and finally adjust the pH value to meet the discharge standards. Although the initially treated wastewater meets the discharge requirements of organic matter, harmful metal ions, etc., it is still high in chloride ions, high in salt, and contains trace amounts of heavy metals. The scope of reuse of the wastewater after meeting the standards is very limited. Therefore, desulfurization wastewater has problems such as small total amount, difficult to treat, and easy to cause secondary pollution. At present, the desulfurization wastewater of most power plants is directly discharged after conventional treatment. Although it can barely meet the discharge standards, the pollution is still very serious.

[0003] In view of this, the present invention utilizes direct contact heat exchange between flue gas and desulfurization wastewater without heat transfer components, thereby avoiding corrosion and scaling problems caused by heat transfer, that is, "zero emission" treatment of desulfurization wastewater. Summary of the invention

[0004] In view of the above problems existing in the prior art, the present invention is proposed.

[0005] Therefore, the first object of the present invention is to propose a desulfurization wastewater discharge system that can solve the above-mentioned technical problems.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a desulfurization wastewater discharge system, comprising a liquid inlet component, an evaporation component, a boiler, a reduction component, and an evaporator, wherein the boiler is connected to the end of the reduction component through a first bypass, and the reduction component passes the boiler tail gas with waste heat after reduction into the evaporator through a second pipeline;

[0007] At least one set of inlet components, including a desulfurization wastewater pipe, a concentration component, an atomization component, and a water addition component;

[0008] At least one set of dust removal components is connected to the bottom of the evaporator.

[0009] As a preferred solution of the desulfurization wastewater discharge system of the present invention, wherein: the reduction component comprises a catalytic reduction box connected to one side of the boiler;

[0010] The bottom of the boiler is connected to a first pipe to pass part of the tail gas into the dust removal component.

[0011] As a preferred solution of the desulfurization wastewater discharge system of the present invention, one side of the first pipeline is connected to the catalytic reduction box and is also connected to the evaporator.

[0012] As a preferred solution of the desulfurization wastewater discharge system of the present invention, wherein: the dust removal component includes a third pipeline connected to the first pipeline, and the evaporator and the catalytic reduction box are connected together at the end of the dust collector;

[0013] And the bottom of the evaporator is connected to the dust collector through a fourth pipeline.

[0014] As a preferred solution of the desulfurization wastewater discharge system of the present invention, the concentration assembly includes a reaction box connected to the desulfurization wastewater pipe, a pre-sedimentation tank connected to the rear end of the reaction box, and a slurry tank connected to the bottom of the pre-sedimentation tank;

[0015] Coagulant and coagulant aid can be added into the reaction box to concentrate the desulfurization wastewater.

[0016] As a preferred solution of the desulfurization wastewater discharge system of the present invention, the atomization assembly includes a spray water tank connected to the rear end of the pre-sedimentation tank and a first water valve arranged at the bottom of the spray water tank.

[0017] As a preferred solution of the desulfurization wastewater discharge system of the present invention, the water adding component includes a cleaning water tank arranged on one side of the spray water tank and a second water valve arranged on one side of the cleaning water tank.

[0018] As a preferred solution of the desulfurization wastewater discharge system of the present invention, the first water valve and the second water valve are connected to a fifth pipe together, and the other end of the fifth pipe is connected to one side of the evaporator;

[0019] The fifth pipeline is also connected with an instrument.

[0020] Another object of the present invention is to provide a method for discharging desulfurization wastewater, which comprises the following steps: high-temperature flue gas generated by the boiler is catalytically reduced in a catalytic reduction box;

[0021] Part of the exhaust gas is directed to the dust removal component and the evaporator respectively through the first pipeline;

[0022] The evaporator receives the hot flue gas as a heat source and evaporates the wastewater after contact;

[0023] The flue gas containing solid residue enters the dust collector through the fourth pipe and is discharged outside the system.

[0024] As a preferred solution of the desulfurization wastewater discharge method of the present invention, the evaporator receives hot flue gas, and the internal sprayers are arranged in a spiral with decreasing temperature, which can ensure that the wastewater is fully evaporated.

[0025] The beneficial effects of the present invention are: the wastewater is directly evaporated by the heat of the boiler tail gas, and the solid particles generated by evaporation are captured by the dust collector and discharged with the soot, without generating additional waste, and the water entering the flue gas with the spray increases the water content of the flue gas, which can reduce the amount of flue gas evaporated water in the subsequent wet desulfurization system and reduce the water consumption of the desulfurization system. The operating cost is low; the concentrated heat source uses the tail flue gas after the boiler dust removal, and does not need to consume other heat sources. It is used to heat the concentrated desulfurization wastewater to achieve the purpose of treating waste with waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 This is a schematic diagram of the desulfurization wastewater discharge system of the present invention.

[0028] Figure 2 The figure is a flow chart of the desulfurization wastewater discharge method of the present invention. DETAILED DESCRIPTION

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0030] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0031] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0032] Example 1

[0033] Reference Figure 1, which is the first embodiment of the present invention, and provides a desulfurization wastewater discharge system, including an evaporation component 100, including a boiler 101, a reduction component 102, and an evaporator 103, wherein the boiler 101 is connected to the end of the reduction component 102 through a first bypass 104, and the reduction component 102 passes the boiler tail gas with waste heat after reduction into the evaporator 103 through a second pipe 105;

[0034] At least one set of inlet components 200, including a desulfurization wastewater pipe 201, a concentration component 202, an atomization component 203, and a water adding component 204;

[0035] At least one set of dust removal components 300 is connected to the bottom of the evaporator 103.

[0036] It should be noted that the evaporation component 100 includes a boiler 101, a reduction component 102, namely an SCR selective catalytic reduction device, and an evaporator 103. The high-temperature flue gas generated by the boiler 101 passes through the SCR component 102, during which nitrogen oxides are effectively removed, thereby reducing the NOx content in the exhaust gas. Subsequently, the treated exhaust gas is guided to the evaporator 103 through the first bypass 104. The second pipeline 105 ensures that the waste heat exhaust gas output from the reduction component 102 can smoothly enter the evaporator 103 as the heat source required for the evaporation process.

[0037] The inlet assembly 200 is composed of a desulfurization wastewater pipe 201, a concentration assembly 202, an atomization assembly 203 and a water adding assembly 204. The desulfurization wastewater from the factory first enters the concentration assembly 202 for preliminary treatment, such as removing suspended solids, heavy metals and other harmful substances. Then, the pre-treated wastewater is sent to the atomization assembly 203, where the wastewater is subdivided into tiny droplets and sprayed into the evaporator 103. In order to maintain the water balance of the system, the water adding assembly 204 can add the necessary amount of water to the system.

[0038] A dust removal assembly 300 is provided at the bottom of the evaporator 103, which is used to capture and collect salt particles and other solid wastes formed during the evaporation process. These particles are mixed with smoke and dust, captured together, and finally discharged from the system in a solid form without generating additional liquid waste.

[0039] Workflow: Desulfurized wastewater first passes through the concentration component 202 to remove most of the pollutants. The treated wastewater is converted into fine droplets by the atomization component 203 and sprayed directly into the evaporator 103. In the evaporator 103, the hot flue gas from the boiler 101 and treated by the SCR component 102 provides heat, so that the wastewater evaporates rapidly to form steam and solid residue. The remaining solid residue after evaporation flows with the flue gas to the dust removal component 300, where it is captured and discharged together with the smoke.

[0040] In summary, the present invention not only achieves efficient and environmentally friendly desulfurization wastewater treatment, but also successfully avoids the corrosion and scaling problems existing in traditional methods, and also reduces the water consumption of the wet desulfurization system. The entire system has a simple structure, low investment and operating costs, and is suitable for thermal power plants and other industrial occasions that need to treat desulfurization wastewater.

[0041] Example 2

[0042] Reference Figure 1 , which is the second embodiment of the present invention, and which is different from the first embodiment in that: it also includes a reduction assembly 102 including a catalytic reduction box 102a connected to one side of the boiler 101;

[0043] The bottom of the boiler 101 is connected to a first pipe 401 to pass part of the tail gas into the dust removal assembly 300 .

[0044] Furthermore, one side of the first pipeline 401 is connected to the catalytic reduction box 102 a and is also connected to the evaporator 103 .

[0045] Further, the dust removal assembly 300 includes a third pipe 301 connected to the first pipe 401, and the evaporator 103 and the catalytic reduction box 102a are connected together at the end of the dust collector 302;

[0046] The bottom of the evaporator 103 is connected to the dust collector 302 through a fourth pipe 303 .

[0047] Further, the concentration assembly 202 includes a reaction box 202a connected to the desulfurization wastewater pipe 201, a pre-sedimentation tank 202b connected to the rear end of the reaction box 202a, and a slurry tank 202c connected to the bottom of the pre-sedimentation tank 202b;

[0048] Coagulants and coagulant aids may be added into the reaction box 202a to concentrate the desulfurization wastewater.

[0049] Furthermore, the atomizing assembly 203 includes a spray water tank 203a connected to the rear end of the pre-sedimentation tank 202b, and a first water valve 203b disposed at the bottom of the spray water tank 203a.

[0050] Furthermore, the water adding assembly 204 includes a cleaning water tank 204a disposed on one side of the spray water tank 203a and a second water valve 204b disposed on one side of the cleaning water tank 204a.

[0051] Furthermore, the first water valve 203b and the second water valve 204b are connected to the fifth pipe 402, and the other end of the fifth pipe 402 is connected to one side of the evaporator 103;

[0052] The fifth pipeline 402 is also connected to a meter 402a.

[0053] It should be noted that this system is a zero-emission treatment system for desulfurization wastewater based on a low-temperature flue gas evaporation process, which uses the waste heat of boiler tail gas to directly evaporate desulfurization wastewater, achieving the environmental protection goal of no additional waste generation. The system includes an evaporation component 100, at least one set of access components 200, and a dust removal component 300. Among them, the boiler 101 generates high-temperature flue gas as the main heat source. The bottom of the boiler 101 is directly connected to the reduction component 102. It includes a catalytic reduction box 102aSCR connected to one side of the boiler 101, which is used for selective catalytic reduction to reduce nitrogen oxides NOx in the tail gas. The first pipe 401 draws part of the tail gas from the bottom of the boiler 101, respectively leading to the dust removal component 300 and the evaporator 103, and is connected to the catalytic reduction box 102a to ensure that the waste heat tail gas can be fully utilized. The evaporator 103 receives hot flue gas from the catalytic reduction box 102a as a heat source. The evaporator 103 is internally arranged with a sprayer step arrangement, and is arranged in a spiral pattern according to the principle that the lower the injection point temperature, the larger the nozzle spacing, so that the concentrated wastewater entering can be fully evaporated. The bottom of the evaporator 103 is connected to the dust collector 302 through the fourth pipe 303, and the solid particles generated by evaporation enter the dust collector with the flue gas and are collected.

[0054] The reaction box 202a is used to add CaOH2, coagulant, coagulant aid, etc. to perform preliminary treatment on the desulfurization wastewater to remove suspended matter, heavy metals, calcium magnesium hardness and other impurities. An appropriate amount of Na2CO3 can be added to the reaction box 202a to adjust the pH value to ensure the best chemical reaction conditions. The pre-sedimentation tank 202b is located at the rear end of the reaction box 202a, and further precipitates and separates, reduces the solid content in the wastewater, and improves the efficiency of subsequent treatment. The slurry tank 202c discharges the concentrated precipitate, and stores the pre-treated wastewater, which is passed into the spray water tank 203a to prepare for the next step of atomization treatment. The spray water tank 203a is connected to the rear end of the pre-sedimentation tank 202b and is used to store the wastewater to be atomized. The spray water tank 203a is equipped with a pressure pump to pressurize the wastewater to an appropriate pressure level to ensure the spray effect. There is a first water valve 203b at the bottom of the spray water tank 203a to control the water flow into the evaporator 103. The cleaning water tank 204a is located on one side of the spray water tank 203a, and provides the system with supplementary water such as flushing water, pump sealing water, etc., to maintain the water balance in the system. The second water valve 204b controls the flow of the cleaning water to ensure the water balance in the system. The second water valve 204b is also equipped with a flow meter for accurately regulating the water volume.

[0055] The fifth pipeline 402 connects the first water valve 203b and the second water valve 204b, and finally connects to one side of the evaporator 103, so as to ensure that the waste water and the make-up water are smoothly introduced into the evaporator. In addition, the fifth pipeline 402 is provided with an instrument 402a to monitor the fluid state, including temperature, pressure and flow monitoring equipment, to ensure safe and reliable operation.

[0056] The third pipeline 301 is connected to the first pipeline 401, and guides part of the exhaust gas that has not passed through the evaporator to the dust collector 302, ensuring that the exhaust gas of the entire system is properly treated.

[0057] The dust collector 302 is located at one end where the evaporator 103 and the catalytic reduction box 102a are connected, and is responsible for collecting solid particles generated during the evaporation process to prevent secondary pollution. It receives solid residues from the bottom of the evaporator 103 through the fourth pipe 303 and discharges them out of the system.

[0058] The desulfurization wastewater first enters the reaction box 202a of the concentration component 202 through the desulfurization wastewater pipe 201. At this stage, CaOH2, coagulants, coagulant aids and other agents are added to remove most of the pollutants through physical and chemical reactions. The wastewater then flows into the pre-sedimentation tank 202b for further precipitation and purification, and is finally stored in the slurry tank 202c to prepare for the next step of atomization treatment. The wastewater in the slurry tank 202c is pumped to the spray water tank 203a and pressurized by a pressure pump. The first water valve 203b controls the injection amount according to the set parameters, forming fine droplets that are directly sprayed into the evaporator 103. At the same time, the water adding component 204 replenishes the necessary water to the system in a timely manner to maintain water balance. The make-up water provided by the cleaning water tank 204a is precisely regulated by the second water valve 204b, and then introduced into the evaporator 103 through the fifth pipe 402 together with the wastewater.

[0059] The evaporator 103 uses the hot flue gas from the boiler 101 and treated by SCR as a heat source to evaporate the wastewater quickly. The sprayers inside the evaporator 103 are arranged in a stepped manner, and are arranged in a spiral pattern according to the principle that the lower the injection point temperature, the larger the nozzle spacing, to ensure that the wastewater can be fully evaporated. The steam formed during the evaporation process flows with the flue gas, while the salt and other solid residues are attached to the flue gas, enter the dust collector 302, are captured and discharged out of the system. The solid residue remaining after evaporation flows with the flue gas to the dust collector 302 and is captured. The demister on the top of the dust collector 302 effectively intercepts possible corrosive droplets and protects the safety of subsequent equipment. The multi-layer filter and electrostatic adsorption device in the dust collector 302 enhance the capture effect and ensure the efficient removal of dust and other particulate matter. The solid waste is finally discharged out of the system through the fourth pipe 303, and no additional liquid waste is generated.

[0060] Part of the tail gas is directly introduced into the dust removal component 300 through the first pipe 401, ensuring that the exhaust gas of the entire system is properly treated to avoid environmental pollution. Another part of the tail gas also passes through the evaporator 103 to participate in the evaporation process before being discharged into the main flue, which does not affect the original dust collector inlet flue gas temperature. This part of the tail gas not only provides the heat required for evaporation, but also increases the moisture content of the flue gas, reducing the water consumption of the subsequent wet desulfurization system.

[0061] In summary, the present invention provides an efficient desulfurization wastewater discharge system, which uses the heat of boiler tail gas to directly evaporate the wastewater, and the solid particles generated by evaporation are captured by the dust collector and discharged with the ash, without generating additional waste, and the water entering the flue gas with the spray increases the water content of the flue gas, which can reduce the amount of flue gas evaporated water in the subsequent wet desulfurization system and reduce the water consumption of the desulfurization system. The operating cost is low; the concentrated heat source uses the tail flue gas after boiler dust removal, and no other heat sources are needed. Since the waste heat of the boiler tail flue gas is difficult to recycle, it is used to heat the concentrated desulfurization wastewater to achieve the purpose of treating waste with waste.

[0062] Example 3

[0063] Reference Figure 2 , which is the third embodiment of the present invention, and which is different from the first two embodiments in that: a desulfurization wastewater discharge system is also provided, which includes a high-temperature flue gas generated by a boiler that is catalytically reduced in a catalytic reduction box;

[0064] Part of the exhaust gas is directed to the dust removal component and the evaporator respectively through the first pipeline;

[0065] The evaporator receives the hot flue gas as a heat source and evaporates the wastewater after contact;

[0066] The flue gas containing solid residue enters the dust collector through the fourth pipe and is discharged outside the system.

[0067] Furthermore, the evaporator receives hot flue gas, and its internal atomizers are arranged in a spiral with decreasing temperature, which can ensure that the wastewater is fully evaporated.

[0068] It should be noted that the high-temperature flue gas generated by the boiler 101 is treated by the SCR catalytic reduction box 102a to reduce the nitrogen oxides NOx in the tail gas, and then part of the tail gas is passed to the dust removal component 300 and the evaporator 103 through the first pipe 401. The evaporator 103 receives the hot flue gas from the catalytic reduction box 102a as a heat source to evaporate the wastewater quickly. The sprayer is arranged in a stepped manner inside the evaporator 103, and is arranged in a spiral manner according to the principle that the lower the injection point temperature, the larger the nozzle spacing, to ensure that the wastewater can be fully evaporated. The steam formed during the evaporation process flows with the flue gas, while the salt and other solid residues are attached to the flue gas, enter the dust collector 302, are captured and discharged out of the system. In order to optimize the evaporation effect, a temperature and humidity sensor is set in the evaporator 103 to dynamically adjust the spray parameters to ensure the best evaporation conditions. The solid residue remaining after evaporation flows with the flue gas to the dust collector 302 and is captured. The demister at the top of the dust collector 302 effectively intercepts possible corrosive droplets and protects the safety of subsequent equipment. The multi-layer filter and electrostatic adsorption device in the dust collector 302 enhance the capture effect and ensure efficient removal of dust and other particulate matter. The solid waste is finally discharged out of the system through the fourth pipe 303 without generating additional liquid waste.

[0069] In summary, the wastewater is directly evaporated by using the heat of the boiler tail gas, and the solid particles generated by evaporation are captured by the dust collector and discharged with the ash, without generating additional waste. The water entering the flue gas with the spray increases the water content of the flue gas, which can reduce the amount of flue gas evaporated water in the subsequent wet desulfurization system and reduce the water consumption of the desulfurization system. The operating cost is low; the concentrated heat source uses the tail flue gas after the boiler dust removal, and no other heat sources are needed. Since the waste heat of the boiler tail flue gas is difficult to recycle, it is used to heat the concentrated desulfurization wastewater to achieve the purpose of treating waste with waste.

[0070] It is important to note that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A desulfurization wastewater discharge system, characterized in that: include, The evaporation component (100) comprises a boiler (101), a reduction component (102), and an evaporator (103), wherein the boiler (101) is connected to the end of the reduction component (102) via a first bypass (104), and the reduction component (102) passes the boiler tail gas with waste heat after reduction into the evaporator (103) via a second pipe (105); At least one set of inlet components (200), including a desulfurization wastewater pipe (201), a concentration component (202), an atomization component (203), and a water adding component (204); At least one set of dust removal components (300) connected to the bottom of the evaporator (103).

2. The desulfurization wastewater discharge system according to claim 1, characterized in that: The reduction assembly (102) comprises a catalytic reduction box (102a) connected to one side of the boiler (101); The bottom of the boiler (101) is connected to a first pipe (401) to pass part of the tail gas into the dust removal component (300).

3. The desulfurization wastewater discharge system according to claim 2, characterized in that: One side of the first pipeline (401) is connected to the catalytic reduction box (102a) and is also connected to the evaporator (103).

4. The desulfurization wastewater discharge system according to claim 3, characterized in that: The dust removal assembly (300) comprises a third pipe (301) connected to the first pipe (401), and the evaporator (103) and the catalytic reduction box (102a) are connected together at the end of the dust collector (302); The bottom of the evaporator (103) is connected to the dust collector (302) via a fourth pipe (303).

5. The desulfurization wastewater discharge system according to claim 4, characterized in that: The concentration assembly (202) comprises a reaction box (202a) connected to the desulfurization wastewater pipe (201), a pre-sedimentation tank (202b) connected to the rear end of the reaction box (202a), and a slurry tank (202c) connected to the bottom of the pre-sedimentation tank (202b); A coagulant and a coagulant aid may be added into the reaction box (202a) to concentrate the desulfurization wastewater.

6. The desulfurization wastewater discharge system according to claim 5, characterized in that: The atomizing assembly (203) comprises a spray water tank (203a) connected to the rear end of the pre-sedimentation tank (202b) and a first water valve (203b) arranged at the bottom of the spray water tank (203a).

7. The desulfurization wastewater discharge system according to claim 6, characterized in that: The water adding assembly (204) comprises a cleaning water tank (204a) arranged on one side of the spray water tank (203a) and a second water valve (204b) arranged on one side of the cleaning water tank (204a).

8. The desulfurization wastewater discharge system according to claim 7, characterized in that: The first water valve (203b) and the second water valve (204b) are connected together to a fifth pipe (402), and the other end of the fifth pipe (402) is connected to one side of the evaporator (103); Furthermore, the fifth pipeline (402) is also connected to a meter (402a).

9. A method for discharging desulfurization wastewater, characterized in that: The desulfurization wastewater discharge method comprises: The high-temperature flue gas generated by the boiler is catalytically reduced in the catalytic reduction box; Part of the exhaust gas is directed to the dust removal component and the evaporator respectively through the first pipeline; The evaporator receives the hot flue gas as a heat source and evaporates the wastewater after contact; The flue gas containing solid residue enters the dust collector through the fourth pipe and is discharged outside the system.

10. The desulfurization wastewater discharge method according to claim 9, characterized in that: The evaporator receives hot flue gas, and its internal sprayers are arranged in a spiral with decreasing temperature, which can ensure that the wastewater is fully evaporated.

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