CN205055798U - Modular wet -type flue gas desulfurization dust collector - Google Patents

Abstract

The utility model proposes a combined wet flue gas desulfurization and dust removal device. The upper part is a tubular electrostatic precipitator, and the lower part is an alkaline desulfurization device. The device includes a cylinder, and a flue gas inlet channel is opened on one side of the bottom. The space at the bottom of the cylinder is a buffer pool. The upper part of the lower spray pipe is equipped with an air flow uniform distribution plate, and the upper part of the air flow uniform distribution plate is an electrostatic precipitator area. The lower spray pipe and the upper spray pipe are respectively connected to the outlet of the booster pump through pipes, and the inlet of the booster pump is connected to the neutralizer. The bottom of the tank and the top of the neutralization tank are provided with lye dosing pipelines, the top of the neutralization tank is connected to the outlet pipe of the booster pump b, the inlet pipe of the booster pump b is connected to the middle of the sedimentation tank, the bottom of the sedimentation tank is connected to the waste liquid outlet, and the sedimentation tank The top is connected to the outlet of the booster pump a, and the inlet pipe of the booster pump a is connected to the bottom of the buffer pool. It mainly solves the problems of low efficiency of flue gas desulfurization and dust removal at the tail of industrial boilers, high energy consumption, and low utilization rate of wastewater.

Description

Combined wet flue gas desulfurization and dust removal device

Technical field:

The utility model relates to the field of air pollution control, in particular to a combined wet flue gas desulfurization and dust removal device.

Background technique:

In recent years, with the occurrence of smog, more and more people have paid attention to air quality and air pollutant emissions, especially boiler flue gas pollutant emissions; power plant boiler flue gas treatment started earlier, in In the country's strict implementation of standards, flue gas treatment and transformation have been carried out in a large area, but the flue gas pollution of industrial boilers is not optimistic. At present, the emission of flue gas pollutants from industrial boilers has exceeded that of power station boilers, becoming the first in the national industrial industry. Large pollution sources, in-depth treatment of industrial boiler flue gas pollution has become inevitable;

The "Boiler Air Pollutant Emission Standard (GB13271-2014)" implemented on July 1, 2014 requires special emission limits for air pollutants: soot particles ≤ 30mg/Nm ³ , SO ₂ ≤ 200mg/Nm ³ , nitrogen oxides ≤200mg/Nm ³ , while the emission limits in key areas and parts of the eastern region have already required soot particles ≤5mg/Nm ³ and SO ₂ ≤100mg/Nm ³ . More than 90%, and the desulfurization efficiency must reach more than 90%. The increasingly stringent emission requirements have made more industrial boiler manufacturers enter the ranks of tail flue gas environmental protection transformation;

The desulfurization of industrial boilers is divided into two methods: dry desulfurization and wet desulfurization. Dry desulfurization generally uses lime (limestone) as a desulfurizing agent, and there are methods such as spraying calcium in the furnace. The utilization rate of desulfurizing agent is low, and the desulfurization efficiency is low. Cannot reach the national limit standard for boiler flue gas emission; wet desulfurization methods include limestone method, double alkali method, magnesium oxide method, sodium alkali method or ammonia method, etc., due to the complexity of the system, the limestone method has high pollution in the operation process and is easy to cause Problems such as system blockage are not commonly used in general industrial boilers; other desulfurization methods, due to the strong alkalinity of the absorbent, have a fast reaction speed with SO ₂ , a high absorption rate, and a high utilization rate of the desulfurizer. Generally, the desulfurization efficiency can reach more than 90%. However, there are also complex wastewater treatment, large initial investment, and high operating costs;

The dust removal methods commonly used in industrial boiler dust removal are also divided into dry type and wet type. The most commonly used dry methods are electric dust removal and bag dust removal. These two methods have huge equipment, high investment and operating costs, and low dust removal efficiency. Can not meet the current national emission standards, water bath type dust collector and stone water film dust collector and wet electrostatic precipitator commonly used in wet dust removal, water bath and stone water film dust removal methods have higher dust removal efficiency, but consume more water , the cost of sewage treatment is high, and the wet electrostatic precipitator is small in size. Due to the existence of electric field force, the dust removal efficiency is very high, and it can reach the emission concentration of flue gas ≤ 5mg/Nm ³ . It has been widely used in power plant boilers.

Invention content:

The utility model patent provides a combined wet flue gas desulfurization and dust removal device, which mainly solves the problems of low efficiency of flue gas desulfurization and dust removal at the tail of industrial boilers, high energy consumption, and low utilization rate of waste water.

The technical solution of the utility model is: a combined wet flue gas desulfurization and dust removal device, which is composed of an upper tubular electrostatic dust removal device and a lower alkaline desulfurization device, wherein the device includes a cylinder, which is an upright cylinder , there is a flue gas inlet channel on one side of the bottom, and the bottom space of the cylinder below the flue gas inlet channel is a buffer pool. Evenly distributed plate, the upper part of the airflow evenly distributed plate is the electrostatic precipitator area, and a number of honeycomb inner hexagonal anode tubes are suspended in the cylinder of the electrostatic precipitator area. The upper space of each anode tube is equipped with nozzles, and several nozzles are connected in parallel through pipes to form the upper part. Spray pipe, the upper part of the cylinder is equipped with a flue gas outlet, the lower spray pipe and the upper spray pipe are respectively connected to the outlet of the booster pump through pipes, the inlet of the booster pump is connected to the bottom of the neutralization tank, and the top of the neutralization tank is equipped with a lye dropper. Add pipelines, the top of the neutralization tank is connected to the outlet pipe of the booster pump b, the inlet pipe of the booster pump b is connected to the middle of the sedimentation tank, the bottom of the sedimentation tank is connected to the waste liquid outlet, the top of the sedimentation tank is connected to the outlet of the booster pump a, and the booster pump a The inlet pipe connects to the bottom of the buffer tank;

The combined wet flue gas desulfurization and dust removal method includes the following steps. The flue gas enters the device through the flue gas inlet pipe. The bottom of the device is a buffer pool for waste liquid after desulfurization. The water in the buffer pool is pumped into the sedimentation tank through the booster pump a, The supernatant liquid of the settling tank is pumped into the neutralization tank through the booster pump b. In the neutralization tank, the absorption liquid after adding lye to adjust the pH through the lye dosing pipeline is circulated into the lower spray pipe and the upper spray In the pipe, the water in the lower part of the sedimentation tank is discharged to the sewage treatment unit; the absorption liquid is atomized and sprayed into the cylinder through the nozzles in the two layers of lower spray pipes, dispersed into fine droplets and covers the entire section of the cylinder, these liquids The lye in the drop contacts with the flue gas in the cylinder countercurrently, the flue gas flow rate is maintained at 3.2-4m/s, and the mass transfer and SO2 absorption reaction occurs. _The absorption liquid is sodium hydroxide alkaline solution, sodium carbonate solution or magnesium oxide dissolved in Magnesium hydroxide solution formed after water digestion; the desulfurized gas flows upward after passing through the air distribution plate, and the flue gas flow rate is between 3 and 4m/s, enters the upper electrostatic dust removal area, and flows through the honeycomb inner hexagon The center of the anode tube is the cathode line matched with the pole, the flue gas flows from bottom to top, the flue gas flow rate is 3-4m/s, the cathode line is discharged under the action of the external high-voltage power supply, and the dust in the flue gas flowing in the tube Particles and water move towards the anode tube under the action of the electric field and adhere to the anode tube. The purified flue gas is discharged from the top, and the anode tube is under the action of the absorption liquid sprayed intermittently from the nozzle on the upper spray pipe. Get cleaned, and the cleaned liquid enters the buffer tank at the bottom of the device.

The utility model has the following beneficial effects: the integrated wet desulfurization and dedusting device and method are formed by combining the tubular electrostatic dust removal and alkaline desulfurization, firstly, a set of water circulation system can be shared, saving investment; secondly, the processing capacity of circulating water is reduced , the operating cost is greatly reduced; again, the interaction of desulfurization and dust removal makes the desulfurization and dust removal efficiency of the device greatly improved, and the emission concentration of the flue gas outlet is reduced. The application mainly solves the problems of low efficiency of desulfurization and dust removal of flue gas at the tail of industrial boilers, high energy consumption, low utilization rate of waste water and the like.

Description of drawings:

Accompanying drawing 1 is the structural representation of the utility model;

Accompanying drawing 2 is A-A view of accompanying drawing 1.

In the figure 1-buffer tank, 2-flue gas inlet channel, 3-cylinder body, 4-electrostatic precipitator area, 5-upper spray pipe, 6-lower spray pipe, 7-flue gas outlet, 8-boost pump , 9-neutralization tank, 10-sedimentation tank, 11-waste liquid outlet, 12-alkali dosing pipeline, 13-anode tube, 14-nozzle, 15-air distribution plate, 16-boost pump a, 17 - booster pump b.

detailed description:

Below in conjunction with accompanying drawing, the utility model is further described:

As shown in Figure 1 combined with Figure 2, the upper part of the combined wet flue gas desulfurization and dust removal device is a tubular electrostatic precipitator, and the lower part is an alkaline desulfurization device. The device includes a cylinder 3, which is an upright cylinder. There is a flue gas inlet channel 2, and the bottom space of the cylinder body 3 at the lower part of the flue gas inlet channel 2 is a buffer pool 1. The upper part of the flue gas inlet channel 2 is provided with two lower spray pipes 6, and the upper part of the lower spray pipe 6 It is the air distribution plate 15, which has the effect of equalizing the air flow of the flue gas. The flue gas after the flow equalization is conducive to electrostatic dust removal and lye sulfur removal. The upper part of the air distribution plate 15 is the electrostatic dust removal area 4 A number of honeycomb-shaped hexagonal anode tubes 13 are suspended in the cylinder body 3 of the electrostatic precipitator area 4, and the center of the anode tube 13 is a cathode line matched with its pole. Under the action of an electric field, the anode tube 13 is used to absorb dust particles in the flue gas , water and part SO ₂ material, the upper space of each anode tube 13 is provided with shower nozzle 14, and several shower nozzles 14 are connected into upper shower pipe 5 in parallel by pipeline, shower nozzle 14 and upper shower pipe 5 are used for cleaning anode tube 13, The upper part of the cylinder body 3 is provided with a flue gas outlet 7, the lower spray pipe 6 and the upper spray pipe 5 are respectively connected to the outlet of the booster pump 8 through pipelines, the inlet of the booster pump 8 is connected to the bottom of the neutralization tank 9, and the top of the neutralization tank 9 is provided with There is a lye dosing pipeline 12, the top of the neutralization tank 9 is connected to the outlet pipe of the booster pump b17, the inlet pipe of the booster pump b17 is connected to the middle of the sedimentation tank 10, the bottom of the sedimentation tank 10 is connected to the waste liquid outlet 11, and the top of the sedimentation tank 10 is connected to The outlet of the booster pump a16, the inlet pipe of the booster pump a16 is connected to the bottom of the buffer pool 1;

The combined wet flue gas desulfurization and dust removal method includes the following steps. The flue gas enters the device through the flue gas inlet pipe 2. The bottom of the device is a buffer pool 1 for waste liquid after desulfurization. The water in the buffer pool 1 is pumped into the sedimentation through the booster pump a16 In the tank 10, the water in the lower part of the settling tank 10 is discharged to the sewage treatment unit; the supernatant of the settling tank 10 is pumped into the neutralization tank 9 through the booster pump b17, and in the neutralization tank 9, through the lye dosing pipeline 12 After adding lye to adjust the pH, the absorption liquid circulates into the lower spray pipe 6 and the upper spray pipe 5, and the absorption liquid is atomized and sprayed into the cylinder 3 through the nozzles in the two-layer upper spray pipe 6, and dispersed into fine particles. The liquid droplets cover the entire section of the cylinder 3. The lye in these droplets is in countercurrent contact with the flue gas in the cylinder 3. The flue gas velocity is maintained at 3.2-4m/s, and the reaction of mass transfer and absorption of SO ₂ occurs, and the absorption liquid Generally, it is an alkaline solution such as sodium hydroxide solution, sodium carbonate solution or magnesium hydroxide solution formed by dissolving magnesium oxide in water and digesting. The desulfurized gas flows upwards after passing through the air flow uniform distribution plate 15. The flue gas flow rate is between 3 and 4m/s, enters the upper electrostatic dust removal area 4, and flows through the honeycomb inner hexagonal anode tube 13, the anode tube 13 The center is the cathode line matched with it, the flue gas flows from bottom to top, the flue gas flow rate is 3-4m/s, the cathode line is discharged under the action of an external high-voltage power supply, and the dust particles and water in the flue gas flowing in the tube are discharged Under the action of the electric field, it moves to the anode tube 13 and adheres to the anode tube 13. The purified flue gas is discharged from the top, and the anode tube 13 is under the action of the absorption liquid sprayed intermittently from the nozzle 14 on the upper spray tube 5. The bottom is cleaned, and the cleaned liquid enters the buffer tank 1 at the bottom of the device.

As an efficient flue gas desulfurization method, the alkali absorption method has a small liquid-to-gas ratio and low energy consumption. The desulfurization absorption liquid is generally an alkaline solution such as sodium hydroxide solution, sodium carbonate solution or magnesium oxide dissolved in water for digestion The resulting magnesium hydroxide solution. The alkaline absorption method has the advantages of high desulfurization efficiency; stable and reliable system operation; less waste water and almost no secondary pollution.

The absorption principle of the alkaline absorption method is as follows: the absorption liquid is atomized and sprayed into the cylinder 3 through the nozzle, dispersed into fine droplets and covers the entire section of the cylinder 3 . The lye in these droplets is in countercurrent contact with the flue gas in the barrel 3 (the flue gas velocity is maintained at 3.2-4m/s), and the reaction of mass transfer and absorption of SO ₂ and SO ₃ occurs. After absorbing SO2, SO3, etc. in the flue gas, it enters the circulation pool. The desulfurization liquid in the circulation pool is re-entered into the circulation pump after the pH value is adjusted by the lye, and is sprayed into the desulfurization cylinder 3 as the absorption liquid.

The principle of wet electrostatic precipitator is as follows: the honeycomb inner hexagonal anode tube is vertically suspended on the fixed channel steel on the top of the precipitator, and the center of the anode tube is the cathode line matched with it. The flue gas flows from bottom to top (flue gas flow rate is 3-4m/s), the cathode line is discharged under the action of an external high-voltage power supply, and the dust particles and water in the flue gas flowing in the tube move to the anode tube under the action of the electric field , and adhere to the anode tube, the purified flue gas is discharged from the top of the dust collector into the chimney, and the anode tube is cleaned under the action of intermittent water spray. The tubular electrostatic precipitator has the advantages of small size, simple system and high dust removal efficiency.

The flue gas enters the device from the bottom of the combined wet desulfurization and dust removal device and flows upwards. The flue gas flow rate is between 3 and 4m/s. Contact, SO ₂ is absorbed by the lye, the flue gas is desulfurized and purified, and in the process, large dust particles are also removed. The temperature of the desulfurized flue gas drops to 50°C and continues to flow upwards. After passing through the air distribution plate 15 in the middle layer, it enters the dust removal area, and the flue gas flow is more uniform. Under the action of the electric field force, the liquid droplets and dust particles in the flue gas Moving to the wall of the anode tube and adhering to the wall of the FRP anode tube, the flue gas is further purified by dedusting and mist removal, and in the process, part of SO ₂ is also removed. The flue gas continues to flow upwards into the chimney and is discharged. The intermittent spray water required by the upper dust removal part is taken from the neutralization tank 9, and after spraying, it goes down through the dust removal and desulfurization parts into the buffer tank at the bottom of the device and then enters the water circulation system.

The supplemented lye is added to the neutralization tank 9, the pH in the tank is adjusted to a suitable value, and it is pumped into the lower spray pipe 6 and the upper spray pipe 5 through the booster pump 8, and the sprayed water from the lower spray pipe 6 is The liquid droplets are mainly used for flue gas desulfurization, and the water sprayed from the upper spray pipe 5 is mainly used for washing the anode tube in the dust removal area. The spray water flows downwards, reaches the buffer tank 1, and is pumped into the settling tank 7, the supernatant liquid is pumped into the neutralization tank 9 to complete the cycle, and the waste liquid in the lower layer is discharged into the wastewater treatment system.

The device and method can achieve a flue gas desulfurization efficiency of more than 90%, a flue gas concentration at the dust removal outlet of ≤5mg/Nm ³ , and meet the current most stringent emission standards in terms of emission; it can realize the reuse of dust removal waste water and greatly reduce the waste water in the operation process Emissions; it can reduce the initial investment of desulfurization and dust removal, and can reduce the energy consumption during operation, so as to achieve the purpose of energy saving and efficiency increase.

Claims (1)

1. A combined wet flue gas desulfurization and dust removal device, characterized in that: it is composed of an upper tubular electrostatic precipitator and a lower alkaline desulfurization device, wherein the device includes a cylinder (3), a cylinder (3) It is an upright cylinder with a flue gas inlet channel (2) on one side of the bottom, the bottom space of the cylinder body (3) below the flue gas inlet channel (2) is a buffer pool (1), and the flue gas inlet channel (2) ) is provided with two lower spray pipes (6), and above the lower spray pipe (6) is provided with an air flow uniform distribution plate (15), and the upper part of the air flow uniform distribution plate (15) is an electrostatic dust removal area (4), Some honeycomb inner hexagonal anode tubes (13) are suspended in the cylinder body (3) of the electrostatic dust removal area (4). The upper space of each anode tube (13) is provided with a nozzle (14), and several nozzles (14) The upper spray pipe (5) is connected in parallel through the pipeline, the upper part of the cylinder (3) is provided with a flue gas outlet (7), and the lower spray pipe (6) and the upper spray pipe (5) are respectively connected to the booster pump ( 8) The outlet and the inlet of the booster pump (8) are connected to the bottom of the neutralization tank (9), the top of the neutralization tank (9) is provided with a lye dosing pipeline (12), and the top of the neutralization tank (9) is connected to the booster pump b (17) outlet pipeline, booster pump b (17) inlet pipeline is connected to the middle part of the sedimentation tank (10), the bottom of the sedimentation tank (10) has a pipeline connected to the waste liquid outlet (11), and the top of the sedimentation tank (10) is connected to the booster pump a (16) outlet, the booster pump a (16) inlet pipeline connects the bottom of buffer pool (1).