Wastewater evaporator and waste heat evaporation type desulfurization wastewater zero discharge process

Abstract

The invention discloses a wastewater evaporator and a waste heat evaporation type desulfurization wastewater zero discharge process, and relates to the technical field of desulfurization wastewater treatment.The wastewater evaporator comprises a device body, a flue gas inlet is formed in the bottom end of the device body, and a flue gas outlet is formed in the top end of the device body; a first group of spray guns, a first-layer static mixer, a second group of spray guns, a second-layer static mixer and a third-layer static mixer are sequentially arranged on the device body from the flue gas inlet to the flue gas outlet; a first accelerator is arranged between the first group of spray guns and the flue gas inlet; and a second accelerator is arranged between the first-layer static mixer and the second group of spray guns. Water and soluble salt in the desulfurization wastewater can be completely separated, the zero discharge target of the wastewater is achieved, water in the wastewater can be rapidly evaporated in the waste heat evaporation process, soluble salt in the wastewater is rapidly crystallized and separated out, the treatment speed is relatively high, and the technology is high in adaptability to the wastewater and low in cost. Desulfurization wastewater with different water qualities, including wastewater with high salt content, high turbidity and high hardness, can be treated.

Description

Technical Field

[0001] The present invention relates to the technical field of desulfurization wastewater treatment, and in particular to a wastewater evaporator and a waste heat evaporation type desulfurization wastewater zero-discharge process. Background Art

[0002] Desulfurization wastewater is mainly the discharge water of the absorber during the wet desulfurization process of boiler flue gas, which is usually composed of wastewater after tailings treatment and process technology cleaning wastewater. The wet desulfurization process is a flue gas desulfurization technology that is widely used in the world. In this process, the desulfurization slurry washes the flue gas in the absorber to remove sulfur dioxide in the flue gas. This process will produce a certain amount of wastewater, but the desulfurization wastewater produced by this process has the characteristics of high salt content and high corrosiveness.

[0003] At the same time, the effluent treated by traditional chemical precipitation methods has saline water characteristics with high sulfate, high hardness (high calcium and high magnesium), and the chloride ions in the wastewater are even more difficult to treat. If discharged directly, it will cause soil salinization, affect the biological growth environment, and cause huge waste of energy.

[0004] Therefore, new technologies are needed to achieve harmless or resourceful treatment of desulfurization wastewater, reuse produced water, and achieve zero wastewater discharge.

[0005] Currently, no effective solution has been proposed for the problems in the related technologies. Summary of the invention

[0006] In view of the problems in the related technology, the present invention proposes a wastewater evaporator and a waste heat evaporation type desulfurization wastewater zero discharge process to overcome the above technical problems existing in the existing related technology.

[0007] The technical solution of the present invention is achieved in this way:

[0008] In one aspect, the present invention:

[0009] A wastewater evaporator comprises: a body, wherein the bottom of the body is provided with a smoke inlet, the top of the body is provided with a smoke outlet, and the body is provided with a first group of spray guns, a first layer of static mixers, a second group of spray guns, a second layer of static mixers and a third layer of static mixers in sequence from the smoke inlet to the smoke outlet, wherein;

[0010] A first accelerator is provided between the first group of spray guns and the smoke inlet, and a second accelerator is provided between the first layer of static mixer and the second group of spray guns;

[0011] The input ends of the first group of spray guns and the second group of spray guns are respectively connected to air compressors.

[0012] Furthermore, the smoke inlet and the smoke outlet are respectively provided with obliquely arranged guide plates, and the input end of the smoke inlet is connected to the production smoke.

[0013] Furthermore, the input ends of the first group of spray guns and the second group of spray guns are connected to the desulfurized wastewater through metering pumps, and the output ends of the first group of spray guns and the second group of spray guns are respectively arranged on both sides of the device body, and the desulfurized wastewater is atomized into droplets of different particle sizes under the action of compressed air from the air compressor.

[0014] Furthermore, a soot blower is provided on the side wall of the device body, and an ash conveying bin pump is provided at the bottom end of the flue gas inlet.

[0015] Another aspect of the present invention is:

[0016] A waste heat evaporation desulfurization wastewater zero discharge process, comprising the following steps:

[0017] The desulfurized wastewater is transported to the first and second spray guns by a metering pump in advance, and the desulfurized wastewater is atomized into droplets of different particle sizes in the first and second spray guns and under the action of compressed air from an air compressor and enters the device body;

[0018] The desulfurized wastewater droplets entering the body come into contact with the hot flue gas entering the body, and the two media, the fully atomized desulfurized wastewater droplets and the hot flue gas entering the evaporator, are fully mixed through the first layer of static mixers, the second layer of static mixers and the third layer of static mixers, and the water therein is fully evaporated to make the soluble salt crystallize, which is then carried out from the flue gas outlet and captured by the subsequent dust collector and mixed with the dust removal ash for unified treatment.

[0019] The following steps are also included:

[0020] Install soot blowers on the side wall of the vessel in advance and open them at preset intervals to prevent dust accumulation and scaling in the flue, the first and second groups of spray guns in the vessel;

[0021] The ash collected in the device body is transported to the ash storage through the ash bin pump.

[0022] The step of transporting the desulfurized wastewater to the first group of spray guns and the second group of spray guns via a metering pump in advance comprises the following steps:

[0023] Rated inlet desulfurization wastewater volume 1m per hour 3 The desulfurization wastewater temperature is 10°C, and is respectively input into the device body through the first and second spray guns, and the output of the first and second spray guns is 0-500L / h;

[0024] The interval between the first group of spray guns and the second group of spray guns is calibrated to be less than 1.5m.

[0025] The step of contacting the desulfurized wastewater droplets entering the body with the hot flue gas entering the body comprises the following steps:

[0026] The hot air volume at the smoke inlet of the calibration body is 165000Nm per hour 3 , flue gas temperature 120℃~150℃;

[0027] The residence time of hot flue gas in the device is calibrated to be >8S.

[0028] The step of fully mixing the two media of the fully atomized desulfurized wastewater droplets and the hot flue gas entering the evaporator comprises the following steps:

[0029] The mixing efficiency of the static mixer is calibrated to be ≥98%.

[0030] Beneficial effects of the present invention:

[0031] 1. The present invention utilizes the waste heat of production flue gas to evaporate the desulfurization wastewater, thereby achieving the effect of zero wastewater discharge, realizing energy recovery and utilization, and reducing treatment costs. Compared with the traditional treatment process that requires additional large amounts of energy consumption, it greatly reduces dependence on external energy, meets the requirements of energy conservation and emission reduction, and reduces greenhouse gas emissions. Since the demand for external energy is reduced, greenhouse gas emissions generated by energy production are also reduced accordingly, which plays a positive role in environmental protection.

[0032] 2. The present invention makes the desulfurization wastewater droplets in the device body contact with the hot flue gas entering the device body, and fully mixes the two media of the fully atomized desulfurization wastewater droplets and the hot flue gas entering the evaporator through the first layer static mixer, the second layer static mixer and the third layer static mixer, fully evaporates the water therein, makes the soluble salt crystallize, and is carried out from the flue gas outlet by the flue gas, which can completely separate the water and soluble salt in the desulfurization wastewater to achieve the goal of zero discharge of wastewater. The waste heat evaporation process can quickly evaporate the water in the wastewater, and make the soluble salt in the wastewater crystallize quickly. The processing speed is relatively fast. The process has strong adaptability to wastewater and can treat desulfurization wastewater of different water quality, including wastewater with high salt content, high turbidity and high hardness.

[0033] 3. The waste heat evaporation type desulfurization wastewater zero-discharge process of the present invention is simple, does not require complicated chemical agent addition and cumbersome operation process, relies on the full mixing of the two media of the fully atomized desulfurization wastewater droplets and the hot flue gas entering the evaporator, fully evaporates the water therein, and crystallizes the soluble salt to achieve wastewater treatment, making the operation of the equipment more stable and reliable, reducing equipment failures and poor treatment effects caused by improper use of chemicals or operating errors. At the same time, for desulfurization wastewater with large water quality fluctuations, the process can adapt better and has strong impact resistance. Even when the wastewater quality changes significantly, it can maintain a relatively stable treatment effect to ensure the continuous operation of the system.

[0034] 4. The water vapor evaporated in the present invention can be condensed and used as recycled water for the desulfurization system, thus realizing the recycling of water resources. At the same time, the crystallized salt substances can be captured by the dust collector and further processed with the mixed dust removal ash, which may have certain utilization value, for example, can be used as industrial raw materials or in other specific fields, thus realizing the recycling and reuse of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. 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.

[0036] Figure 1 It is a structural schematic diagram of a wastewater evaporator and a waste heat evaporation type desulfurization wastewater zero-discharge process according to an embodiment of the present invention.

[0037] In the figure:

[0038] 1. Device body; 2. Smoke inlet; 3. Smoke outlet; 4. First group of spray guns; 5. Second group of spray guns; 6. First layer of static mixer; 7. Second layer of static mixer; 8. Third layer of static mixer; 9. First accelerator; 10. Second accelerator; 11. Guide plate. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0040] According to an embodiment of the present invention, a wastewater evaporator is provided.

[0041] like Figure 1 As shown, the wastewater evaporator according to an embodiment of the present invention comprises: a body 1, a smoke inlet 2 is provided at the bottom of the body 1, a smoke outlet 3 is provided at the top of the body 1, and the body 1 is provided with a first group of spray guns 4, a first layer of static mixer 6, a second group of spray guns 5, a second layer of static mixer 7 and a third layer of static mixer 8 in sequence from the smoke inlet 2 to the smoke outlet 3, wherein;

[0042] A first accelerator 9 is provided between the first group of spray guns 4 and the smoke inlet 2, and a second accelerator 10 is provided between the first layer of static mixer 6 and the second group of spray guns 5;

[0043] The input ends of the first group of spray guns 4 and the second group of spray guns 5 are connected to air compressors respectively.

[0044] The smoke inlet 2 and the smoke outlet 3 are respectively provided with obliquely arranged guide plates 11, and the input end of the smoke inlet 2 is connected to the production smoke.

[0045] In addition, the input ends of the first group of spray guns 4 and the second group of spray guns 5 are connected to the desulfurized wastewater through a metering pump, and the output ends of the first group of spray guns 4 and the second group of spray guns 5 are respectively arranged on both sides of the device body 1, and the desulfurized wastewater is atomized into droplets of different particle sizes under the action of compressed air from the air compressor.

[0046] In this technical solution, after the desulfurization wastewater is initially treated to remove large particle impurities, it is sent to the first group of spray guns 4 and the second group of spray guns 5 through a metering pump. The inlet wastewater volume is 1m per hour. 3 , wastewater temperature 10℃.

[0047] At the same time, for the above-mentioned first group of spray guns 4 and second group of spray guns 5, they are arranged in two layers, arranged on the short side, and the interval between the two layers of spray guns is not more than 1.5m. Each group can use two spray guns distributed on both sides of the body 1, and the spray gun material is at least 316L dual-fluid spray gun. The spray gun must have anti-blocking measures, and the output of each spray gun is 0-500L / h.

[0048] In addition, the flue gas inlet 2 is 165000Nm per hour. 3 Considering that the flue gas temperature is 120℃-150℃, the flue gas residence time in the evaporator shall not be less than 8 seconds.

[0049] In addition, three layers of static mixers are arranged inside the body 1, namely, a first layer of static mixer 6, a second layer of static mixer 7 and a third layer of static mixer 8, and the mixing efficiency of the static mixers is ≥98%.

[0050] In addition, a soot blower is provided on the side wall of the body 1, and an ash conveying bin pump is provided at the bottom end of the flue gas inlet 2.

[0051] In this technical solution, the soot blower is installed on the side wall of the wastewater evaporator and is opened regularly to avoid ash accumulation and scaling in the flue, the first group of spray guns 4 and the second group of spray guns 5. At the same time, the ash silo pump is used to transport the ash collected by the wastewater evaporator to the ash storage for stirring and mixing to avoid excessive concentration of crystallized salt, which affects the quality and comprehensive utilization of the ash.

[0052] According to an embodiment of the present invention, a waste heat evaporation type desulfurization wastewater zero discharge process is provided.

[0053] like Figure 1 As shown, the waste heat evaporation desulfurization wastewater zero discharge process according to an embodiment of the present invention includes the following steps:

[0054] The desulfurized wastewater is transported to the first group of spray guns 4 and the second group of spray guns 5 by a metering pump in advance, and the desulfurized wastewater is atomized into droplets of different particle sizes in the first group of spray guns 4 and the second group of spray guns 5 and under the action of compressed air from an air compressor and enters the body 1;

[0055] The desulfurized wastewater droplets entering the body 1 come into contact with the hot flue gas entering the body 1, and the two media, the fully atomized desulfurized wastewater droplets and the hot flue gas entering the evaporator, are fully mixed through the first layer static mixer 6, the second layer static mixer 7 and the third layer static mixer 8, and the water therein is fully evaporated, so that the soluble salt is crystallized and is carried out from the flue gas outlet 3 by the flue gas.

[0056] The following steps are also included:

[0057] A soot blower is pre-installed on the side wall of the body 1 and opened at a preset period to prevent dust accumulation and scaling in the flue, the first group of spray guns 4 and the second group of spray guns 5 in the body 1;

[0058] The ash collected by the body 1 is transported to the ash storage by an ash conveying bin pump.

[0059] The step of pre-transporting the desulfurized wastewater to the first group of spray guns 4 and the second group of spray guns 5 via a metering pump comprises the following steps:

[0060] Rated inlet desulfurization wastewater volume 1m per hour 3 The desulfurization wastewater temperature is 10°C, and is respectively input into the body 1 through the first group of spray guns 4 and the second group of spray guns 5, and the output of the first group of spray guns 4 and the second group of spray guns 5 is 0-500L / h;

[0061] The interval between the first group of spray guns 4 and the second group of spray guns 5 is calibrated to be less than 1.5 m.

[0062] The step of contacting the desulfurized wastewater droplets entering the body 1 with the hot flue gas entering the body 1 comprises the following steps:

[0063] The hot air volume of the smoke inlet 2 of the calibration body 1 is 165000Nm per hour 3 , flue gas temperature 120℃~150℃;

[0064] The residence time of the hot flue gas in the device body 1 is calibrated to be greater than 8S.

[0065] The step of fully mixing the two media of the fully atomized desulfurized wastewater droplets and the hot flue gas entering the evaporator comprises the following steps:

[0066] The mixing efficiency of the static mixer is calibrated to be ≥98%.

[0067] In addition, it should be noted that the amount of water consumed depends on the flue gas temperature and flue layout conditions. In order to ensure the safe operation of the system, the amount of water evaporated by the system should be controlled at a low level. Its operation control needs to be considered comprehensively. On the premise of ensuring the safe and stable operation of the system, the amount of wastewater to be treated should be reduced to achieve energy saving and consumption reduction in system operation.

[0068] In summary, with the help of the above technical solution of the present invention, the following effects can be achieved:

[0069] 1. The present invention utilizes the waste heat of production flue gas to evaporate the desulfurization wastewater, thereby achieving the effect of zero wastewater discharge, realizing energy recovery and utilization, and reducing treatment costs. Compared with the traditional treatment process that requires additional large amounts of energy consumption, it greatly reduces dependence on external energy, meets the requirements of energy conservation and emission reduction, and reduces greenhouse gas emissions. Since the demand for external energy is reduced, greenhouse gas emissions generated by energy production are also reduced accordingly, which plays a positive role in environmental protection.

[0070] 2. The present invention makes the desulfurization wastewater droplets in the body 1 contact with the hot flue gas entering the body 1, and fully mixes the two media of the fully atomized desulfurization wastewater droplets and the hot flue gas entering the evaporator through the first layer static mixer 6, the second layer static mixer 7 and the third layer static mixer 8, fully evaporates the water therein, makes the soluble salt crystallize, and is carried out from the flue gas outlet 3 by the flue gas, which can completely separate the water and salt in the desulfurization wastewater to achieve the goal of zero discharge of wastewater. The waste heat evaporation process can quickly evaporate the water in the wastewater, and make the soluble salt in the wastewater quickly crystallize and precipitate. The processing speed is relatively fast. The process has strong adaptability to wastewater and can treat desulfurization wastewater of different water qualities, including wastewater with high salt content, high turbidity and high hardness.

[0071] 3. The waste heat evaporation type desulfurization wastewater zero-discharge process of the present invention is simple, does not require complicated chemical agent addition and cumbersome operation process, relies on the full mixing of the two media of the fully atomized desulfurization wastewater droplets and the hot flue gas entering the evaporator, fully evaporates the water therein, and crystallizes the soluble salt to achieve wastewater treatment, making the operation of the equipment more stable and reliable, reducing equipment failures and poor treatment effects caused by improper use of chemicals or operating errors. At the same time, for desulfurization wastewater with large water quality fluctuations, the process can adapt better and has strong impact resistance. Even when the wastewater quality changes significantly, it can maintain a relatively stable treatment effect to ensure the continuous operation of the system.

[0072] 4. The water vapor evaporated in the present invention can be condensed and used as recycled water for the desulfurization system, thus realizing the recycling of water resources. At the same time, the crystallized salt substances can be captured by the dust collector and further processed with the mixed dust removal ash, which may have certain utilization value, for example, can be used as industrial raw materials or in other specific fields, thus realizing the recycling and reuse of resources.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. After considering the disclosure of the specification and the examples, those skilled in the art will easily think of other embodiments of the present disclosure. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the art that are not disclosed in the present disclosure. The specification and the examples are only regarded as exemplary, and the true scope and spirit of the present disclosure are indicated by the claims.

[0074] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A wastewater evaporator, characterized in that: include: A body (1), wherein a smoke inlet (2) is provided at the bottom of the body (1), a smoke outlet (3) is provided at the top of the body (1), and the body (1) is provided with a first group of spray guns (4), a first layer of static mixer (6), a second group of spray guns (5), a second layer of static mixer (7) and a third layer of static mixer (8) in sequence from the smoke inlet (2) to the smoke outlet (3), wherein; A first accelerator (9) is provided between the first group of spray guns (4) and the smoke inlet (2), and a second accelerator (10) is provided between the first layer of static mixer (6) and the second group of spray guns (5); The input ends of the first group of spray guns (4) and the second group of spray guns (5) are respectively connected to air compressors.

2. The wastewater evaporator according to claim 1, characterized in that: The smoke inlet (2) and the smoke outlet (3) are respectively provided with obliquely arranged flow guide plates (11), and the input end of the smoke inlet (2) is connected to the production smoke.

3. The wastewater evaporator according to claim 2, characterized in that: The input ends of the first group of spray guns (4) and the second group of spray guns (5) are connected to the desulfurized wastewater through metering pumps, and the output ends of the first group of spray guns (4) and the second group of spray guns (5) are respectively arranged on both sides of the device body (1), and the desulfurized wastewater is atomized into droplets of different particle sizes under the action of compressed air from an air compressor.

4. The wastewater evaporator according to claim 1, characterized in that: A soot blower is also provided on the side wall of the device body (1), and an ash conveying bin pump is provided at the bottom end of the smoke inlet (2).

5. A waste heat evaporation type desulfurization wastewater zero discharge process, used for the waste water evaporator of any one of claims 1 to 4, comprising the following steps: The desulfurized wastewater is transported to the first group of spray guns (4) and the second group of spray guns (5) via a metering pump in advance, and the desulfurized wastewater is atomized into droplets of different particle sizes in the first group of spray guns (4) and the second group of spray guns (5) and under the action of compressed air from an air compressor and then enters the device body (1); The desulfurized wastewater droplets entering the vessel body (1) come into contact with the hot flue gas entering the vessel body (1), and the two media, the fully atomized desulfurized wastewater droplets and the hot flue gas entering the evaporator, are fully mixed through the first layer static mixer (6), the second layer static mixer (7) and the third layer static mixer (8), so that the water therein is fully evaporated, the soluble salt is crystallized, and is carried out by the flue gas from the flue gas outlet (3).

6. The waste heat evaporation desulfurization wastewater zero discharge process according to claim 5 is characterized in that: The following steps are also included: A soot blower is pre-installed on the side wall of the vessel body (1) and is opened at a preset period to prevent dust accumulation and scaling in the flue, the first group of spray guns (4) and the second group of spray guns (5) in the vessel body (1); The ash collected by the device body (1) is transported to the ash storage via an ash transport bin pump.

7. The waste heat evaporation desulfurization wastewater zero discharge process according to claim 5 is characterized in that: The step of transporting the desulfurized wastewater to the first group of spray guns (4) and the second group of spray guns (5) via a metering pump in advance comprises the following steps: Rated inlet desulfurization wastewater volume 1m per hour 3 The desulfurization wastewater has a temperature of 10°C and is fed into the device body (1) through a first group of spray guns (4) and a second group of spray guns (5), respectively, and the output of the first group of spray guns (4) and the second group of spray guns (5) is 0-500L / h; The interval between the first group of spray guns (4) and the second group of spray guns (5) is calibrated to be less than 1.5 m.

8. The waste heat evaporation desulfurization wastewater zero discharge process according to claim 5 is characterized in that: The step of contacting the desulfurized wastewater droplets entering the body (1) with the hot flue gas entering the body (1) comprises the following steps: The hot air volume of the smoke inlet (2) of the calibration device (1) is 165000Nm per hour. 3 , flue gas temperature 120℃~150℃; The residence time of the hot flue gas in the device body (1) is calibrated to be greater than 8 seconds.

9. The waste heat evaporation desulfurization wastewater zero discharge process according to claim 5 is characterized in that: The step of fully mixing the two media of the fully atomized desulfurized wastewater droplets and the hot flue gas entering the evaporator comprises the following steps: The mixing efficiency of the static mixer is calibrated to be ≥98%.

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