CN107344788B - Desulfurization wastewater treatment system - Google Patents
Desulfurization wastewater treatment system Download PDFInfo
- Publication number
- CN107344788B CN107344788B CN201710786674.2A CN201710786674A CN107344788B CN 107344788 B CN107344788 B CN 107344788B CN 201710786674 A CN201710786674 A CN 201710786674A CN 107344788 B CN107344788 B CN 107344788B
- Authority
- CN
- China
- Prior art keywords
- flue
- desulfurization wastewater
- bicarbonate
- treatment system
- desulfurization
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000006477 desulfuration reaction Methods 0.000 title claims abstract description 113
- 230000023556 desulfurization Effects 0.000 title claims abstract description 113
- 238000004065 wastewater treatment Methods 0.000 title claims abstract description 46
- 239000002351 wastewater Substances 0.000 claims abstract description 121
- 238000001704 evaporation Methods 0.000 claims abstract description 61
- 230000008020 evaporation Effects 0.000 claims abstract description 61
- BVKZGUZCCUSVTD-UHFFFAOYSA-M Bicarbonate Chemical compound OC([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-M 0.000 claims abstract description 59
- 239000000872 buffer Substances 0.000 claims abstract description 43
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 43
- 239000012530 fluid Substances 0.000 claims abstract description 35
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims abstract description 10
- JLVVSXFLKOJNIY-UHFFFAOYSA-N Magnesium ion Chemical compound [Mg+2] JLVVSXFLKOJNIY-UHFFFAOYSA-N 0.000 claims abstract description 10
- 239000011575 calcium Substances 0.000 claims abstract description 10
- 229910001424 calcium ion Inorganic materials 0.000 claims abstract description 10
- 229910001425 magnesium ion Inorganic materials 0.000 claims abstract description 10
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 claims description 28
- 238000001514 detection method Methods 0.000 claims description 16
- 229910000030 sodium bicarbonate Inorganic materials 0.000 claims description 14
- 235000017557 sodium bicarbonate Nutrition 0.000 claims description 14
- 238000004140 cleaning Methods 0.000 claims description 7
- 238000010907 mechanical stirring Methods 0.000 claims description 5
- 229910000028 potassium bicarbonate Inorganic materials 0.000 claims description 5
- 235000015497 potassium bicarbonate Nutrition 0.000 claims description 5
- 239000011736 potassium bicarbonate Substances 0.000 claims description 5
- TYJJADVDDVDEDZ-UHFFFAOYSA-M potassium hydrogencarbonate Chemical compound [K+].OC([O-])=O TYJJADVDDVDEDZ-UHFFFAOYSA-M 0.000 claims description 5
- 239000012716 precipitator Substances 0.000 claims description 5
- 239000002253 acid Substances 0.000 claims description 4
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 abstract description 31
- 239000003546 flue gas Substances 0.000 abstract description 31
- 238000006243 chemical reaction Methods 0.000 abstract description 14
- 239000002918 waste heat Substances 0.000 abstract description 14
- 238000000034 method Methods 0.000 abstract description 12
- 230000000694 effects Effects 0.000 abstract description 11
- 230000008569 process Effects 0.000 abstract description 11
- 230000009471 action Effects 0.000 abstract description 8
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 abstract description 6
- 239000007789 gas Substances 0.000 abstract description 6
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 abstract description 4
- 239000007788 liquid Substances 0.000 abstract description 4
- 239000001569 carbon dioxide Substances 0.000 abstract description 3
- 229910002092 carbon dioxide Inorganic materials 0.000 abstract description 3
- 239000007791 liquid phase Substances 0.000 abstract description 3
- 238000010438 heat treatment Methods 0.000 abstract description 2
- 238000000354 decomposition reaction Methods 0.000 abstract 1
- 239000000428 dust Substances 0.000 description 15
- 239000002245 particle Substances 0.000 description 9
- 230000009467 reduction Effects 0.000 description 7
- 238000000889 atomisation Methods 0.000 description 6
- 239000000243 solution Substances 0.000 description 6
- 239000010865 sewage Substances 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 4
- 238000005406 washing Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 239000003595 mist Substances 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 239000003245 coal Substances 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000011010 flushing procedure Methods 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000000779 smoke Substances 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000012265 solid product Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 description 1
- 229910000013 Ammonium bicarbonate Inorganic materials 0.000 description 1
- 235000012538 ammonium bicarbonate Nutrition 0.000 description 1
- 239000001099 ammonium carbonate Substances 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000005352 clarification Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000003009 desulfurizing effect Effects 0.000 description 1
- 238000000909 electrodialysis Methods 0.000 description 1
- 238000005189 flocculation Methods 0.000 description 1
- 230000016615 flocculation Effects 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 238000010979 pH adjustment Methods 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/02—Treatment of water, waste water, or sewage by heating
- C02F1/04—Treatment of water, waste water, or sewage by heating by distillation or evaporation
- C02F1/10—Treatment of water, waste water, or sewage by heating by distillation or evaporation by direct contact with a particulate solid or with a fluid, as a heat transfer medium
- C02F1/12—Spray evaporation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/46—Removing components of defined structure
- B01D53/48—Sulfur compounds
- B01D53/50—Sulfur oxides
- B01D53/501—Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound
- B01D53/504—Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound characterised by a specific device
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/46—Removing components of defined structure
- B01D53/48—Sulfur compounds
- B01D53/50—Sulfur oxides
- B01D53/501—Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound
- B01D53/505—Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound in a spray drying process
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/02—Treatment of water, waste water, or sewage by heating
- C02F1/04—Treatment of water, waste water, or sewage by heating by distillation or evaporation
- C02F1/16—Treatment of water, waste water, or sewage by heating by distillation or evaporation using waste heat from other processes
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
- C02F1/5236—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents
- C02F1/5245—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents using basic salts, e.g. of aluminium and iron
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/18—Nature of the water, waste water, sewage or sludge to be treated from the purification of gaseous effluents
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Organic Chemistry (AREA)
- Hydrology & Water Resources (AREA)
- Life Sciences & Earth Sciences (AREA)
- Water Supply & Treatment (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Health & Medical Sciences (AREA)
- Biomedical Technology (AREA)
- Analytical Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Inorganic Chemistry (AREA)
- Treating Waste Gases (AREA)
- Heat Treatment Of Water, Waste Water Or Sewage (AREA)
Abstract
The invention provides a desulfurization wastewater treatment system, which comprises a wastewater buffer tank; the pretreatment system is arranged at the inlet end of the wastewater buffer tank; bicarbonate dosing device for dosing bicarbonate into the wastewater buffer tank; the air inlet of the double-fluid atomizing nozzle is connected with an air compressor, and the water inlet is connected with the water outlet of the wastewater buffer tank through a water pump. After the desulfurization waste water enters the flue, the desulfurization waste water begins to evaporate under the action of the waste heat of the flue gas; the desulfurization wastewater can be mixed with SO in the flue gas 3 The reaction occurs; the desulfurization waste water is easy to generate decomposition reaction under the condition of heating; the carbon dioxide gas generated by the two reactions can further accelerate the disturbance of liquid drops, secondary fog drops are easy to form, and meanwhile, the reaction between gas and liquid phases inevitably accelerates the heat and mass transfer process of the fog drops and flue gas; in addition, the generated carbonate can react with a small amount of soluble calcium and magnesium ions in the desulfurization wastewater to nucleate rapidly and release heat, so that the evaporation time of fog drops can be effectively shortened, and the zero emission effect of the wastewater is improved.
Description
Technical Field
The invention relates to the technical field of waste water treatment of thermal power plants, in particular to a desulfurization waste water treatment system.
Background
The main sewage of the coal-fired power plant is as follows: domestic sewage, coal-containing wastewater, circulating water cooling tower sewage and desulfurization wastewater. The sewage of domestic sewage, coal-containing waste water, circulating water cooling tower, etc. is generally treated by simple physical and chemical treatment and reused as make-up water in desulfurizing tower. The desulfurization wastewater is used as the terminal wastewater of the coal-fired power plant, has the characteristics of poor water quality, complex components, high salinity, difficult recycling and the like, and is always a key problem of zero emission of wastewater of the whole coal-fired power plant.
The flue gas waste heat evaporation technology is used as a brand new, efficient and economic zero-emission technology of desulfurization waste water, and has great application potential in realizing zero emission of coal-fired power plants. The principle of the technology is that desulfurization waste water which is highly atomized by a gas-liquid double-fluid atomizer is sprayed into a flue between an air preheater and a dust remover, under the heating action of waste heat of flue gas, fog drop moisture is completely evaporated, salt is evaporated and crystallized into solid particles along with the moisture, and the solid particles are captured by the dust remover to enter dry ash, so that zero emission of the waste water is achieved.
For a unit with complex and changeable flue gas working conditions and large desulfurization wastewater discharge amount, in order to ensure the stability of the desulfurization wastewater flue gas waste heat evaporation treatment system, desulfurization wastewater needs to be subjected to reduction treatment.
For a flue gas waste heat evaporation system, the stability of the system can be ensured only if the actual evaporation time of fog drops is smaller than the allowable evaporation time of the fog drops. The actual evaporation time of the fog drops is determined by the grain diameter of the fog drops and the temperature of the smoke at which the fog drops are positioned, and the allowable evaporation time of the fog drops is determined by the ratio of the length of an evaporation flue to the flow rate of the smoke. Therefore, the evaporation time required by the complete evaporation of the larger atomized particle size is longer, and the limited evaporation flue length is easy to cause difficulty in meeting the evaporation time required by the complete evaporation of the larger atomized particle size; or the length of the evaporation flue is shorter, so that the evaporation time required by complete evaporation of the atomized particle size is difficult to meet, and the zero emission effect of the wastewater is influenced.
In summary, how to shorten the evaporation time of the mist droplets of the desulfurization wastewater in the evaporation flue so as to improve the zero emission effect of the wastewater is a technical problem to be solved by those skilled in the art.
Disclosure of Invention
Therefore, the invention aims to provide a desulfurization wastewater treatment system, which shortens the evaporation time of fog drops of desulfurization wastewater in an evaporation flue, thereby improving the zero emission effect of wastewater.
In order to achieve the above purpose, the present invention provides the following technical solutions:
a desulfurization wastewater treatment system comprising a wastewater buffer tank, further comprising:
the pretreatment system can remove calcium and magnesium ions in the desulfurization wastewater, and is arranged at the inlet end of the wastewater buffer tank;
bicarbonate dosing device for dosing bicarbonate into the wastewater buffer tank;
the double-fluid atomizing nozzle is characterized in that an air inlet of the double-fluid atomizing nozzle is connected with an air compressor, and a water inlet of the double-fluid atomizing nozzle is connected with a water outlet of the wastewater buffer tank through a water pump.
Preferably, in the desulfurization wastewater treatment system, the bicarbonate dosing device is a sodium bicarbonate dosing device or a potassium bicarbonate dosing device; the mass fraction of bicarbonate added by the bicarbonate adding device is 5% -20%.
Preferably, in the desulfurization wastewater treatment system, the bicarbonate dosing device is arranged above the wastewater buffer tank.
Preferably, the desulfurization wastewater treatment system further comprises a mechanical stirring device arranged in the wastewater buffer tank.
Preferably, in the desulfurization wastewater treatment system, a flue between an air preheater and an electric dust collector of the desulfurization wastewater treatment system comprises:
a main flue;
and the bypass flue is arranged in parallel with the main flue, the double-fluid atomizing nozzle of the desulfurization wastewater treatment system is positioned in the bypass flue and is close to the inlet end, the inlet end of the bypass flue is provided with an inlet valve, and the outlet end of the bypass flue is provided with an outlet valve.
Preferably, in the desulfurization wastewater treatment system, a centrifugal fan close to the outlet end is further arranged in the bypass flue, and the distance between the two-fluid atomizing nozzle and the centrifugal fan is greater than 20m.
Preferably, in the desulfurization wastewater treatment system, the bypass flue is a U-shaped flue, a middle straight flue section of the U-shaped flue is parallel to the main flue, and the two-fluid atomizing nozzle and the centrifugal fan are both arranged on the middle straight flue section.
Preferably, in the desulfurization wastewater treatment system, the desulfurization wastewater treatment system further includes a temperature detection device for detecting a temperature in the middle straight flue section, the temperature detection device includes:
and a plurality of temperature detection elements are uniformly arranged from the front 1m of the two-fluid atomizing nozzle to the rear 20m of the two-fluid atomizing nozzle along the length direction of the middle straight flue section, and the distance between two adjacent temperature detection elements is 1m.
Preferably, in the desulfurization wastewater treatment system, a reduction system is further arranged between the wastewater buffer tank and the pretreatment system.
Preferably, in the desulfurization wastewater treatment system, the desulfurization wastewater treatment system further comprises an evaporation pipeline cleaning device, wherein the evaporation pipeline cleaning device can sequentially carry out acid washing and clear water flushing on a pipeline through which desulfurization wastewater containing bicarbonate flows.
According to the technical scheme, the desulfurization wastewater treatment system provided by the invention comprises a wastewater buffer tank; the pretreatment system can remove calcium and magnesium ions in the desulfurization wastewater, and is arranged at the inlet end of the wastewater buffer tank; bicarbonate dosing device for dosing bicarbonate into the wastewater buffer tank; the double-fluid atomizing nozzle has air inlet connected to the air compressor and water inlet connected via water pump to the water outlet of the waste water buffering tank.
When the desulfurization wastewater treatment system is applied, desulfurization wastewater flowing out of the desulfurization tower enters a wastewater buffer box after calcium and magnesium ions in the desulfurization wastewater are removed by a pretreatment system; then adding a certain amount of bicarbonate into the wastewater buffer tank through a bicarbonate dosing device; then, under the action of air provided by an air compressor, the desulfurization wastewater containing bicarbonate pumped by a water pump is sprayed into a flue between the air preheater and the electric dust collector through a double-fluid atomizing nozzle, the desulfurization wastewater containing bicarbonate is evaporated by utilizing flue gas waste heat, and the evaporated solid product enters the electric dust collector and is collected and removed by the electric dust collector; the atomization degree of the double-fluid atomization nozzle is higher, and the evaporation efficiency is higher.
After the desulfurization wastewater containing bicarbonate enters a flue, the desulfurization wastewater begins to evaporate under the action of flue gas waste heat; a first partIn aspects, the desulfurization wastewater containing bicarbonate will react with SO in the flue gas 3 The following reactions occur:
2HCO 3 - +SO 3 →SO 4 2- +2CO 2 ↑+H 2 O ①
on the other hand, desulfurization wastewater containing bicarbonate is susceptible to the following reaction when heated:
2HCO 3 - →CO 3 2- +CO 2 ↑+H 2 O ②
the carbon dioxide gas generated by the two reactions can further accelerate the disturbance of liquid drops, secondary fog drops are easy to form, and meanwhile, the reaction between gas and liquid phases inevitably accelerates the heat and mass transfer process of the fog drops and flue gas; in addition, carbonate generated in the formula (2) can react with a small amount of soluble calcium and magnesium ions in the desulfurization wastewater to nucleate rapidly, and emit heat, so that the fog drop evaporation time can be effectively shortened, and further complete evaporation of the desulfurization wastewater can be still realized under the condition of larger atomization particle size or allowable shorter evaporation flue length. Therefore, the addition of bicarbonate can shorten the evaporation time of fog drops of desulfurization wastewater in the evaporation flue, thereby improving the zero emission effect of wastewater.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of a desulfurization wastewater treatment system according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of another embodiment of a desulfurization wastewater treatment system according to an embodiment of the present invention.
In FIG. 1-2, 1-boiler, 2-economizer, 3-air preheater, 4-bi-fluid atomizing nozzle, 5-electric precipitator, 6-desulfurizing tower, 7-pretreatment system, 8-reduction system, 9-wastewater buffer tank, 10-mechanical stirring device, 11-bicarbonate dosing device, 12-water pump, 13-air compressor, 14-temperature detection device, 15-bypass flue, 16-centrifugal fan.
Detailed Description
The embodiment of the invention provides a desulfurization wastewater treatment system, which shortens the evaporation time of fog drops of desulfurization wastewater in an evaporation flue, thereby improving the zero discharge effect of wastewater.
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Referring to fig. 1-2, a desulfurization wastewater treatment system provided by an embodiment of the present invention includes a wastewater buffer tank 9; the pretreatment system 7 can remove calcium and magnesium ions in the desulfurization wastewater, and the pretreatment system 7 is arranged at the inlet end of the wastewater buffer tank 9 and a bicarbonate dosing device 11 for dosing bicarbonate into the wastewater buffer tank 9; the double-fluid atomizing nozzle 4, the air inlet of the double-fluid atomizing nozzle 4 is connected with an air compressor 13, and the water inlet is connected with the water outlet of the wastewater buffer tank 9 through a water pump 12. In this embodiment, the water outlet of the wastewater buffer tank 9 is connected to a water pump 12, and the water outlet of the water pump 12 and the air provided by the air compressor 13 are converged in the two-fluid atomizing nozzle 4.
The desulfurization wastewater treatment system comprises a boiler 1, an economizer 2, an air preheater 3, an electric dust collector 5, a desulfurization tower 6 and a pretreatment system 7 which are sequentially connected, wherein the inlet of a wastewater buffer tank 9 is connected with the outlet of the pretreatment system 7; the desulfurization waste water treatment device further comprises a two-fluid atomizing nozzle 4 capable of atomizing desulfurization waste water, wherein an outlet of the two-fluid atomizing nozzle 4 is arranged in a flue between the air preheater 3 and the electric dust collector 5. The pretreatment system 7 refers to a traditional process treatment route of neutralization, precipitation, flocculation, clarification, softening, pH adjustment and the like, and mainly aims to remove heavy metals, suspended matters and calcium and magnesium ions in the desulfurization wastewater, and is a conventional treatment system.
When the desulfurization wastewater treatment system is applied, desulfurization wastewater flowing out of the desulfurization tower 6 enters a wastewater buffer box 9 after calcium and magnesium ions in the desulfurization wastewater are removed by a pretreatment system 7; then adding a certain amount of bicarbonate into the wastewater buffer tank 9 through a bicarbonate adding device 11; then, under the action of air provided by an air compressor 13, the desulfurization wastewater containing bicarbonate, which is pumped out by a water pump 12, is sprayed into a flue between the air preheater 3 and the electric dust collector 5 through a double-fluid atomizing nozzle 4, the desulfurization wastewater containing bicarbonate is evaporated by utilizing flue gas waste heat, and the solid product after evaporation enters the electric dust collector 5 and is further collected and removed by the electric dust collector 5; the two-fluid atomizing nozzle 4 has a higher atomization degree and a higher evaporation efficiency.
After the desulfurization wastewater containing bicarbonate enters a flue, the desulfurization wastewater begins to evaporate under the action of flue gas waste heat; on the one hand, desulfurization wastewater containing bicarbonate can be mixed with SO in flue gas 3 The following reactions occur:
2HCO 3 - +SO 3 →SO 4 2- +2CO 2 ↑+H 2 O ①
on the other hand, desulfurization wastewater containing bicarbonate is susceptible to the following reaction when heated:
2HCO 3 - →CO 3 2- +CO 2 ↑+H 2 O ②
the carbon dioxide gas generated by the two reactions can further accelerate the disturbance of liquid drops, secondary fog drops are easy to form, and meanwhile, the reaction between gas and liquid phases inevitably accelerates the heat and mass transfer process of the fog drops and flue gas; in addition, carbonate generated in the formula (2) can react with a small amount of soluble calcium and magnesium ions in the desulfurization wastewater to nucleate rapidly, and emit heat, so that the fog drop evaporation time can be effectively shortened, and further complete evaporation of the desulfurization wastewater can be still realized under the condition of larger atomization particle size or allowable shorter evaporation flue length. Therefore, the addition of bicarbonate can shorten the evaporation time of fog drops of desulfurization wastewater in the evaporation flue, thereby improving the zero emission effect of wastewater.
In addition, the invention can shorten the fog drop evaporation time without changing any flue structure and nozzle device, reduce the treatment cost and improve the adaptability of the whole desulfurization wastewater treatment system to various unit working conditions. And because the desulfurization wastewater containing bicarbonate can be mixed with SO in the flue gas 3 The reaction is carried out, SO that the SO is removed cooperatively 3 Is a target of (a).
Furthermore, after the desulfurization wastewater containing bicarbonate is evaporated, carbonate is generated, and the compound is used as a chemical conditioner to increase the particle conductivity, and after entering the electric dust collector 5, the dust collection efficiency of the electric dust collector 5 is improved. The invention has reliable technology, simple and convenient operation, enhances the atomization effect by utilizing chemical reaction, does not generate any harmful products in the reaction, is environment-friendly, and has good economic and social benefits.
In a specific embodiment, bicarbonate dosing device 11 is a sodium bicarbonate dosing device or a potassium bicarbonate dosing device. In the embodiment, sodium bicarbonate is added into the wastewater buffer tank 9 through a sodium bicarbonate dosing device, or potassium bicarbonate is added into the wastewater buffer tank 9 through a potassium bicarbonate dosing device, and sodium bicarbonate is preferably selected, so that the cost is low. Of course, the bicarbonate may be ammonium bicarbonate or the like.
Preferably, the bicarbonate adding device 11 adds 5% -20% of bicarbonate by mass, and can shorten the evaporation time of desulfurization wastewater on the premise of adding as little bicarbonate as possible, thereby reducing the cost. Of course, according to the desulfurization waste water with different components, the mass fraction of the bicarbonate can also be other values, such as 25%.
In order to facilitate the addition of bicarbonate, a bicarbonate dosing device 11 is arranged above the wastewater buffer tank 9. Thus, under the action of gravity, the bicarbonate at the outlet of the bicarbonate adding device 11 can enter the wastewater buffer tank 9, so that the structure is simple, and the cost is saved. The bicarbonate adding device 11 can also be arranged on one side of the wastewater buffer tank 9, and bicarbonate can be added by means of a spiral pushing device.
In order to make the mixing of bicarbonate and desulfurization wastewater more uniform, the desulfurization wastewater treatment system further includes a mechanical stirring device 10 provided in the wastewater buffer tank 9. According to the invention, bicarbonate added into desulfurization wastewater is uniformly stirred by a mechanical stirring device 10 to obtain desulfurization wastewater containing bicarbonate. Of course, the invention can also make the wastewater buffer tank 9 have stirring function by vibrating or rotating, so as to realize the same effect of uniformly mixing bicarbonate and desulfurization wastewater.
In a specific embodiment of the present invention, as shown in fig. 2, the flue between the air preheater 3 and the electric precipitator 5 of the desulfurization waste water treatment system comprises a main flue and a bypass flue 15 arranged in parallel with the main flue, and the two-fluid atomizing nozzle 4 of the desulfurization waste water treatment system is positioned in the bypass flue 15 and near the inlet end. According to the invention, a bypass flue 15 is led out between the electric precipitator 5 and the air preheater 3, and the flue gas waste heat in the bypass flue 15 is utilized to evaporate the desulfurization waste water containing bicarbonate, so that the flue gas finally returns to the front of the electric precipitator 5. Of course, the flue of the invention can also only comprise a main flue, namely the flue existing between the air preheater 3 and the electric dust collector 5 in the original structure, and as shown in fig. 1, the flue gas waste heat in the main flue is utilized to evaporate the desulfurization waste water containing bicarbonate.
In order to facilitate control of the on-off of the flue gas of the bypass flue 15, it is preferable that the inlet end of the bypass flue 15 is provided with an inlet valve, and the outlet end is provided with an outlet valve.
In a further technical scheme, a centrifugal fan 16 close to the outlet end is further arranged in the bypass flue 15, and the distance between the double-fluid atomizing nozzle 4 and the centrifugal fan 16 is more than 20m. The distance can ensure that fog drops are completely evaporated, and the zero emission effect of wastewater is ensured. When the atomized particle diameter of the mist droplets is small (less than 50 μm), the distance between the two-fluid atomizing nozzle 4 and the centrifugal fan 16 may be less than 20m, such as 18m, or the like.
Preferably, the bypass flue 15 is a U-shaped flue, a middle straight flue section of the U-shaped flue is parallel to the main flue, and the double-fluid atomizing nozzle 4 and the centrifugal fan 16 are both arranged on the middle straight flue section. The U-shaped flue comprises two end flue sections which are arranged in parallel and a middle straight flue section which is vertically connected between the two end flue sections, the flue gas flow of the middle straight flue section is more stable, and the evaporation effect is higher.
To further optimize the above technical solution, the desulfurization wastewater treatment system further comprises a temperature detection device 14 for detecting the temperature in the middle straight flue section. It should be noted that, due to the limitation of the actual working condition of the pipeline, the evaporation time cannot be directly measured, but when the fog drops are sprayed into the flue, the flue gas temperature has a steady trend after falling along with the flue, and the fog drops are evaporated when the steady trend is reached, the distance between the temperature balance point after falling and the nozzle is the evaporation distance of the fog drops. Therefore, the evaporation distance of the mist droplets can be determined by the temperature detection device 14 described above.
In this embodiment, the temperature detecting device 14 includes a plurality of temperature detecting elements uniformly arranged from the front 1m of the two-fluid atomizing nozzle 4 to the rear 20m of the two-fluid atomizing nozzle 4 along the length direction of the middle straight flue section, and the distance between two adjacent temperature detecting elements is 1m. The number of the temperature detection elements is 22, the temperature detection precision is high, and the obtained fog drop evaporation distance precision is high. Of course, the invention can also be provided with a temperature detection element every 1.5m or 2 m.
The invention is carried out by a test bench in a power plant using the embodiment shown in fig. 2. In order to enhance the stability of the test platform, the test directly adopts process water to replace desulfurization wastewater to examine the influence of water before and after adding bicarbonate on evaporation time. The method comprises the following specific steps:
1) According to the schematic diagram shown in fig. 2, the components of the pilot test platform are installed;
2) When the power plant boiler 1 stably runs, opening an inlet valve and an outlet valve, starting a centrifugal fan 16, maintaining a certain flue gas flow in a flue, and starting a temperature detection device 14;
3) Pumping process water into a wastewater buffer tank 9;
4) Starting a water pump 12 and an air compressor 13, controlling certain pressure and flow, spraying the process water sprayed by the water pump 12 into a bypass flue 15 through a double-fluid atomizing nozzle 4 under the action of air provided by the air compressor 13, and then observing the change of the flue temperature through a temperature detection device 14;
5) After the temperature in the flue is stable, finding the distance between the balance point and the nozzle after the temperature is reduced, wherein the distance is the evaporation distance of the process water without sodium bicarbonate;
6) Under the condition that the working condition is kept unchanged, adding a certain amount of sodium bicarbonate into the process water to prepare 10% sodium bicarbonate solution, repeating the steps 4 and 5, and finding the evaporation distance of the process water containing the sodium bicarbonate;
7) After the test is completed, the injection water pump 12, the air compressor 13, the centrifugal fan 16, the inlet valve and the outlet valve are sequentially closed.
The conditions and results of the test are shown in the following table:
| sequence number | Project | Unit (B) | Parameters (parameters) |
| 1 | Flow rate of flue gas | m 3 /h | 20000 |
| 2 | Flue gas temperature | ℃ | 122 |
| 3 | Flow rate of flue gas | m/s | 8.8 |
| 4 | Air compressor pressure | bar | 4 |
| 5 | Air compressor air quantity | Nm 3 /h | 93 |
| 6 | Pressure of water pump 12 | bar | 1.6 |
| 7 | Flow rate of water pump 12 | L/min | 1 |
| 8 | Evaporation distance without sodium bicarbonate | m | 14 |
| 9 | Evaporation distance in the presence of sodium bicarbonate | m | 12 |
The test results show that under the same working condition and test condition, the evaporation distance is reduced by 2m and the evaporation time is shortened by 15% after the sodium bicarbonate is added into the process water, and the evaporation time of fog drops is shortened after the sodium bicarbonate is added.
As shown in fig. 1, a reduction system 8 is further provided between the wastewater buffer tank 9 and the pretreatment system 7. For a unit with complex and changeable flue gas working conditions and large desulfurization waste water discharge amount, in order to ensure the stability of a desulfurization waste water flue gas waste heat evaporation treatment system, desulfurization waste water needs to be subjected to reduction treatment, and the desulfurization waste water flowing out of a desulfurization tower 6 enters a waste water buffer box 9 after being treated by a conventional pretreatment system 7 and a reduction system 8. The reduction system 8 is membrane treatment or electrodialysis treatment, the pH value of the effluent is 7-8, and the main purposes of the system are to reduce the amount of waste water evaporated by waste heat of flue gas, reduce the cost and improve the stability of the waste heat evaporation system of flue gas. The invention can also be provided with no reduction system 8, so that the desulfurization wastewater flowing out of the desulfurization tower 6 only enters the wastewater buffer box 9 after being treated by the pretreatment system 7.
The desulfurization wastewater treatment system further comprises an evaporation pipeline cleaning device, and the evaporation pipeline cleaning device can sequentially carry out acid washing and clear water flushing on a pipeline through which desulfurization wastewater containing bicarbonate flows. When the boiler 1 is to be stopped, the evaporation pipeline cleaning device uses low-concentration acid washing for the whole evaporation pipeline and then uses clear water for washing, so that the desulfurization wastewater containing bicarbonate can be prevented from depositing on the pipeline. The present invention may also not include an evaporation tube cleaning device.
In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A desulfurization wastewater treatment system comprising a wastewater buffer tank (9), characterized by further comprising:
the pretreatment system (7) can remove calcium and magnesium ions in the desulfurization wastewater, and the pretreatment system (7) is arranged at the inlet end of the wastewater buffer tank (9);
bicarbonate dosing means (11) for dosing bicarbonate into the wastewater buffer tank (9);
the double-fluid atomizing nozzle (4), an air inlet of the double-fluid atomizing nozzle (4) is connected with an air compressor (13), and a water inlet is connected with a water outlet of the wastewater buffer tank (9) through a water pump (12).
2. The desulfurization wastewater treatment system according to claim 1, characterized in that the bicarbonate dosing device (11) is a sodium bicarbonate dosing device or a potassium bicarbonate dosing device; the mass fraction of bicarbonate added into the bicarbonate adding device (11) is 5% -20%.
3. The desulfurization wastewater treatment system according to claim 1, characterized in that the bicarbonate dosing device (11) is arranged above the wastewater buffer tank (9).
4. The desulfurization wastewater treatment system according to claim 1, further comprising a mechanical stirring device (10) provided in the wastewater buffer tank (9).
5. The desulfurization wastewater treatment system according to claim 4, characterized in that a flue between an air preheater (3) and an electric precipitator (5) of the desulfurization wastewater treatment system comprises:
a main flue;
and the bypass flue (15) is arranged in parallel with the main flue, the two-fluid atomizing nozzle (4) is positioned in the bypass flue (15) and is close to the inlet end, the inlet end of the bypass flue (15) is provided with an inlet valve, and the outlet end of the bypass flue is provided with an outlet valve.
6. The desulfurization wastewater treatment system according to claim 5, characterized in that a centrifugal fan (16) close to the outlet end is further arranged in the bypass flue (15), and the distance between the two-fluid atomizing nozzle (4) and the centrifugal fan (16) is more than 20m.
7. The desulfurization wastewater treatment system according to claim 6, characterized in that the bypass flue (15) is a U-shaped flue, a middle straight flue section of the U-shaped flue is parallel to the main flue, and the two-fluid atomizing nozzle (4) and the centrifugal fan (16) are both arranged in the middle straight flue section.
8. The desulfurization wastewater treatment system of claim 7, further comprising a temperature detection device (14) for detecting a temperature within the middle straight flue section, the temperature detection device (14) comprising:
and a plurality of temperature detection elements are uniformly arranged from the front 1m of the two-fluid atomizing nozzle (4) to the rear 20m of the two-fluid atomizing nozzle (4) along the length direction of the middle straight flue section, and the distance between two adjacent temperature detection elements is 1m.
9. The desulfurization wastewater treatment system according to claim 1, characterized in that a abatement system (8) is further provided between the wastewater buffer tank (9) and the pretreatment system (7).
10. The desulfurization wastewater treatment system of any one of claims 1-9, further comprising an evaporation pipe cleaning device capable of sequentially performing an acid wash and a clear water rinse on a pipe through which desulfurization wastewater containing bicarbonate flows.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710786674.2A CN107344788B (en) | 2017-09-04 | 2017-09-04 | Desulfurization wastewater treatment system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710786674.2A CN107344788B (en) | 2017-09-04 | 2017-09-04 | Desulfurization wastewater treatment system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107344788A CN107344788A (en) | 2017-11-14 |
| CN107344788B true CN107344788B (en) | 2023-11-14 |
Family
ID=60258152
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710786674.2A Active CN107344788B (en) | 2017-09-04 | 2017-09-04 | Desulfurization wastewater treatment system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107344788B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108176202A (en) * | 2017-12-26 | 2018-06-19 | 北京亘源环保有限公司 | A kind of preparation method and application of desulfuration adsorbent |
| CN108751562A (en) * | 2018-08-29 | 2018-11-06 | 上海电气电站环保工程有限公司 | A kind of industrial wastewater treatment system |
| CN109557062A (en) * | 2018-12-10 | 2019-04-02 | 徐州工程学院 | A kind of desulfurization wastewater drop evaporation test device and test method |
| CN111747588A (en) * | 2020-05-29 | 2020-10-09 | 华电电力科学研究院有限公司 | Large-flow high-salinity wastewater full-load continuous flue gas evaporation zero-emission treatment process |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102380278A (en) * | 2011-09-22 | 2012-03-21 | 东南大学 | Method for cooperatively promoting agglomeration growth of PM (particulate matter) 2.5 and treating desulfuration wastewater in evaporation manner and device of method |
| CA2818271A1 (en) * | 2012-06-08 | 2013-12-08 | Alstom Technology Ltd. | Compact air quality control system compartment for aluminium production plant |
| WO2015154687A1 (en) * | 2014-04-09 | 2015-10-15 | 苏州鼎德电环保科技有限公司 | Gas-liquid-solid separator, gas-liquid separator and plasma desulphuration and denitration apparatus comprising same |
| CN105879542A (en) * | 2016-03-07 | 2016-08-24 | 上海龙净环保科技工程有限公司 | Power plant desulfurization wastewater bypass treatment system and method and flue gas treatment system and method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4489695B2 (en) * | 2005-12-08 | 2010-06-23 | 株式会社ジーシー | Extruding device for tooth restoration material mixed and kneaded in capsule |
-
2017
- 2017-09-04 CN CN201710786674.2A patent/CN107344788B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102380278A (en) * | 2011-09-22 | 2012-03-21 | 东南大学 | Method for cooperatively promoting agglomeration growth of PM (particulate matter) 2.5 and treating desulfuration wastewater in evaporation manner and device of method |
| CA2818271A1 (en) * | 2012-06-08 | 2013-12-08 | Alstom Technology Ltd. | Compact air quality control system compartment for aluminium production plant |
| WO2015154687A1 (en) * | 2014-04-09 | 2015-10-15 | 苏州鼎德电环保科技有限公司 | Gas-liquid-solid separator, gas-liquid separator and plasma desulphuration and denitration apparatus comprising same |
| CN105879542A (en) * | 2016-03-07 | 2016-08-24 | 上海龙净环保科技工程有限公司 | Power plant desulfurization wastewater bypass treatment system and method and flue gas treatment system and method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107344788A (en) | 2017-11-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107344788B (en) | Desulfurization wastewater treatment system | |
| CN109052526B (en) | High-salt-content wastewater zero discharge system for flue gas white elimination coupling high-temperature bypass flue evaporation | |
| CN107162084B (en) | Saline water treatment system with front heat exchanger and rear dust remover and method thereof | |
| CN103982903B (en) | System and method for treating tail end waste water by using smoke waste heat | |
| CN104724779B (en) | Neat stress recirculation type desulfurization wastewater spraying treatment system | |
| CN105417604B (en) | Utilize the method and device of fume afterheat processing desulfurization wastewater | |
| CN105457468B (en) | The technique that a kind of tower boiler flue gas recycled is atomized desulfurization wastewater | |
| CN106673101B (en) | Deep treatment method and system for high-salt-content desulfurization wastewater | |
| CN208008493U (en) | A kind of equipment that flue residue heat is used for Waste Water From Fire Power Plant zero discharge treatment | |
| CN204569462U (en) | Neat stress recirculation type desulfurization wastewater spraying treatment unit | |
| CN105668832A (en) | Desulfurization wastewater treatment system and method | |
| CN104150552A (en) | Distillation drying tower for treating desulfurized waste water in thermal power plant | |
| CN103058435A (en) | Method for circularly processing hot boiler flue gas and desulfurization wastewater | |
| CN205590344U (en) | Processing system of desulfurization waste water | |
| CN107827306A (en) | A kind of thermal power plant desulfurization wastewater zero-discharge treatment system | |
| CN207361979U (en) | A kind of desulfurization wastewater treatment system | |
| CN209383589U (en) | A kind of desulfurization wastewater multi-heat source coupled processing system | |
| CN205590492U (en) | Device of multistage evaporating treatment desulfurization waste water of flue | |
| CN104689676A (en) | Wet-process desulfurization wastewater utilization system and process | |
| CN205461708U (en) | Tower boiler is process units of recirculated flue gas atomizing desulfurization waste water again | |
| CN209759208U (en) | Desulfurization waste water evaporation concentration zero-discharge system | |
| CN205419832U (en) | Energy -efficient waste water evaporated crystallizer | |
| CN112679022B (en) | Low-temperature concentration desulfurization wastewater zero discharge system | |
| CN209952568U (en) | Wet flue desulfurization waste water flue sprays evaporation zero release processing system | |
| CN106986401A (en) | A kind of method for treating desulfurized wastewater |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |