CN204502785U - A kind of flue gas device for deep cleaning for efficient desulfurizing and dust collecting - Google Patents

Abstract

The utility model relates to a flue gas deep purification device for high-efficiency desulfurization and dust removal, comprising an absorption tower, a slurry pool and a flue gas absorption area above the slurry pool are arranged in the absorption tower, and a circulating slurry spray device is arranged at the flue gas inlet The flue gas absorption area is divided into the first absorption area and the second absorption area located on the side of the first absorption area with a partition, and the flue gas flowing from the first absorption area to the second absorption area is set between the partition and the slurry pool. Channel, the first slurry spraying layer is set in the first absorption area, the second slurry spraying layer is set in the second absorption area, the first slurry spraying layer, the second slurry spraying layer and the circulating slurry spraying device are all passed through the slurry circulating pump It is connected with the slurry tank, and above the second slurry spray layer, a mist eliminator, a dust collector and a flue gas outlet are arranged in sequence from bottom to top. The device simultaneously realizes the deep purification of flue gas desulfurization and dust removal in one device, reduces the height of the absorption tower, reduces the resistance of flue gas flow, saves construction costs and reduces its operating costs.

Description

A flue gas deep purification device for efficient desulfurization and dust removal

technical field

The utility model relates to a flue gas deep purification device for desulfurization and dust removal.

Background technique

With the development of China's economy, environmental pollution is becoming more and more serious, and large-scale haze weather occurs from time to time. In order to improve the environment, at present, more than 80% of international and domestic flue gas desulfurization processes use limestone-gypsum wet desulfurization process, flue gas limestone ——The gypsum wet desulfurization process generally adopts a single absorption tower. With the continuous improvement of environmental protection requirements, the emission limit of pollutants in the flue gas of coal-fired power plants in economically developed areas and some urban agglomerations in China is required to meet the emission requirements of gas turbine units, that is, The so-called "ultra-clean emission" requires that the NOx concentration in the exhaust gas be ≤50mg/Nm ³ , the SO ₂ concentration be ≤35mg/Nm ³ , and the soot concentration be ≤5mg/Nm ³ . According to this new requirement, the actual desulfurization efficiency of many coal-fired power plants should reach more than 99%. It is already difficult to meet this new requirement with the single-tower process in the past. Therefore, there are now two-tower double-cycle processes and single-tower double-cycle processes. Among them, the double-tower double-circulation process is to connect two absorption towers in series and install a wet electrostatic precipitator behind the second absorption tower. This process has complex flue, large flue gas resistance, large floor space, and high power consumption for operation. . The single-tower double-circulation process is actually a variation of the double-tower double-circulation process, that is, the spray layers of the two towers are superimposed and arranged up and down, and a liquid-receiving tray is set between the spray layers of the tower and the tower to make the spray of the previous absorption tower The shower liquid is not sprayed into the next absorption tower, and the slurry pool of the upper absorption tower is arranged outside the absorption tower. The disadvantage of this process is that the absorption tower is very high, and the wet electrostatic precipitator cannot be installed on it, and the wet electrostatic precipitator can only be horizontal. The layout increases the complexity of the flue and increases the resistance of the flue gas. There are two slurry tanks, the operation control is complicated, the operation cost is high, and the investment cost is high.

Utility model content

The technical problem solved by the utility model is to simplify the flue gas treatment device for desulfurization and dust removal, and use a flue gas absorption tower to simultaneously realize double-cycle absorption of flue gas, remove fine particle dust, and reduce the height of the absorption tower.

The technical scheme of the utility model is to provide a flue gas treatment device for desulfurization and dust removal, including an absorption tower, a slurry pool and a flue gas absorption area above the slurry pool are arranged in the absorption tower, and a circulating slurry is arranged at the flue gas inlet. The spray device uses a partition to divide the smoke absorption area into the first absorption area and the second absorption area located on the side of the first absorption area. The flue gas return channel, the first slurry spraying layer is set in the first absorption area, the second slurry spraying layer is set in the second absorption area, the first slurry spraying layer, the second slurry spraying layer and the circulating slurry spraying device all pass through The slurry circulation pump is connected with the slurry pool, and the mist eliminator, dust collector and flue gas outlet are arranged sequentially above the second slurry spray layer from bottom to top.

Further, a cooling spray protection device is also provided at the entrance of the flue gas, and the cooling spray protection device is connected to the water source through the automatic control valve; a flow detector is installed between the slurry circulating pump and the circulating slurry spray device, and the flow detector Connect with automatic control valve.

Further, a stirring device and an oxidizing air distribution device are installed in the slurry pool.

Further, the dust collector is a wet electrostatic precipitator.

Further, the position of the flue gas outlet is higher than the position of the flue gas inlet.

Further, the inner wall of the absorption tower is provided with a rubber-lined or glass flake-lined anti-corrosion layer.

The flue gas enters from the flue gas inlet, and first sprays the slurry through the circulating slurry spraying device (including spray pipes and nozzles) to cool down the flue gas; when the circulating slurry spraying device or the slurry circulation pump connected to it fails, the cooling system will The spray protection device sprays water to cool down the flue gas. The cooling spray protection device is connected to the standing water source, and an automatic control valve is installed on the water source pipeline; the automatic control valve and the flow detector, the flow detector can detect the circulating slurry spray When there is no slurry flow in the shower device, the automatic control valve is opened, and the cooling spray protection device sprays water to the inlet flue gas to cool down to protect the inner lining of the absorption tower and the slurry spray layer; after the flue gas enters the first absorption zone, it flows from top to bottom , spray the slurry through the first slurry spray layer to absorb sulfur dioxide and dust in the flue gas; then enter the second absorption zone through the flue gas return channel, flow from bottom to top, and then spray the slurry through the second slurry spray layer to further absorb the flue gas The sulfur dioxide and dust in the gas are discharged through the mist eliminator, dust collector and flue gas outlet.

The wet electrostatic precipitator is directly installed on the upper part of the first absorption area and the second absorption area, supported by the lower absorption tower, so as to solve the problem that the flue gas velocity of the existing vertical wet electrostatic precipitator is slower than that in the absorption tower and the single absorption The installation position on the top of the tower is not enough. Compared with the wet electrostatic precipitator installed on the horizontal flue, this installation makes the flue very short, with few elbows, and no need to design brackets.

The lower part of the absorption tower is a slurry tank, the first absorption zone and the second absorption zone share a slurry tank, and the slurry tank is designed as other desulfurization devices, with structures such as a slurry stirring device and an oxidation air distribution device.

This device is used for the removal of sulfur dioxide, soot and other PM2.5 in the flue gas. When the sulfur dioxide content at the flue gas inlet is 7000 mg/Nm ³ and the dust is 50 mg/Nm ³ , the treatment of this device can make the removal of sulfur dioxide The efficiency reaches over 99.5%, the outlet SO ₂ <35mg/Nm ³ , and the smoke concentration <5mg/Nm ³ . This method adopts the commonly used limestone-gypsum wet flue gas desulfurization method. The difference is that the device and method use an absorption tower including two absorption tower areas combined into one whole, and a single slurry tank to achieve a desulfurization efficiency of over 99.5%. Ground and wet electrostatic precipitator in one. The device improves the effect of flue gas desulfurization and dust removal, reduces the height of the absorption tower, reduces the resistance of flue gas flow, and saves construction investment and device operation cost. It is superior to the existing ultra-clean emission technologies such as double-tower double-cycle process or single-tower double-cycle process in terms of energy saving, site saving, and investment cost reduction.

Description of drawings

Fig. 1 shows the schematic diagram of the structure and principle of the flue gas treatment device provided by the utility model;

In the figure 1: flue gas inlet; 2: circulating slurry spraying device; 3: first slurry spraying layer; 4: flue gas return channel; 5: second slurry spraying layer; 6: slurry circulating pump; 7: slurry pool; 8: mist eliminator; 9: dust collector; 10: water source; 11: flow detector; 12: automatic control valve; 13: cooling spray protection device; 14: clapboard; 15: flue gas outlet.

Detailed ways

The utility model is described in detail below according to the accompanying drawings and embodiments.

The flue gas purification device provided in this embodiment includes an absorption tower, a slurry pool 7 and a flue gas absorption area located above the slurry pool 7 are arranged in the absorption tower, a circulating slurry spraying device 2 is set at the flue gas inlet 1, and a separator 14 The smoke absorption area is divided into the first absorption area and the second absorption area located on the side of the first absorption area, and the flue gas return channel flowing from the first absorption area to the second absorption area is set between the separator 14 and the slurry pool 7 4. Set the first slurry spray layer 3 in the first absorption zone, set the second slurry spray layer 5 in the second absorption zone, the first slurry spray layer 3, the second slurry spray layer 5 and the circulating slurry spray device 2 Both are connected to the slurry tank 7 through the slurry circulation pump 6, and the mist eliminator 8, the dust collector 9 and the flue gas outlet 15 are sequentially arranged above the second slurry spray layer 5 from bottom to top. A cooling spray protection device 13 is also provided at the flue gas inlet 1, and the cooling spray protection device 13 is connected to the water source 10 through the automatic control valve 12; a flow detection is set between the slurry circulating pump 6 and the circulating slurry spray device 2 Instrument 11, flow detector 11 is connected with automatic control valve 12.

The flue gas to be purified enters the absorption tower of the flue gas treatment device from the flue gas inlet 1 at the top of the side of the device. The flue at the inlet is lined with wear-resistant and corrosion-resistant alloy, and a circulating slurry spray device 2 is installed at the flue inlet. , to cool down the flue gas to protect the anti-corrosion lining material and internal parts of the absorption tower from being damaged by the impact of high temperature, and at the same time to wash the flue gas for the first time. In order to save investment, the inner wall of the absorption tower is anti-corrosion with rubber lining or glass flake lining. The slurry spray pipe is made of FRP material. The rubber lining and glass flake lining material can withstand a temperature of 90 ° C. The flue gas that the FRP pipeline can withstand The temperature is 80°C, and the flue gas temperature is generally above 100°C. The inlet section is equipped with a circulating spray device 2, which can reduce the flue gas temperature to 70°C without damaging the above-mentioned materials. In order to prevent the sudden failure of the circulating slurry spraying device 2 in the flue inlet 1 and stop spraying, a cooling spraying protection device 13 is installed behind the circulating spraying device 2 in the inlet section, and the cooling spraying protection device 13 is connected to the standing water source 10. An automatic control valve 12 is installed on the water inlet pipe. When the circulation spraying device in the inlet section is in normal operation, the automatic control valve 12 is closed. 12 is opened, and the cooling spray protection device 13 sprays water to cool down the flue gas spray. A flow detector 11 is installed on the water inlet pipe of the circulating spray device, and the flow detector 11 is connected with the automatic control valve 12 to control the opening and closing of the automatic control valve 12. Then the flue gas enters the flue gas absorption area, which is divided into two left and right absorption areas by the partition plate 14, which are respectively the first absorption area and the second absorption area. The partition plate 14 is arranged vertically or substantially vertically. The lower end of the plate does not contact the liquid surface of the slurry pool 7 to form a flue gas return channel; the flue gas enters the first absorption zone after preliminary cooling, flows from top to bottom, and sprays with the first slurry set in the middle of the first absorption zone The slurry sprayed from layer 3 contacts, and the pollutants SO ₂ , dust, HCl, HF, etc. in the flue gas are washed by the slurry, and the washed flue gas continues to descend, and enters through the flue gas return channel 4 after reaching the liquid level of the slurry pool at the bottom of the tower. In the second absorption zone, the flue gas turns back to flow upwards and contacts again with the slurry sprayed from the second slurry spray layer 5 in the middle of the second absorption zone, and the pollutants SO ₂ , dust, HCl, HF, etc. in the flue gas are The slurry is further washed off. The washed flue gas continues to rise, passes through the mist eliminator 8 installed on the upper part to remove mist droplets, and then enters the electrostatic precipitator 9 through the flue gas flow field adjustment section to capture fine dust and SO ₃ and other pollution in the flue gas After the material is discharged from the flue gas outlet 15. The slurry sprayed by the first slurry spray layer 3 and the second slurry spray layer 5 all come from the public slurry pool 7 at the lower part of the tower, contact with the flue gas and wash the pollutants in the flue gas, and then fall into the slurry pool 7, the slurry pool Containing a large amount of limestone and gypsum solution, the slurry tank 7 is equipped with a stirring device to prevent the precipitation of limestone and gypsum; _SO2 is dissolved in water after being absorbed by the slurry to generate sulfurous acid, and air is filled into the slurry tank to oxidize the sulfurous acid into sulfuric acid, which is combined with the slurry Calcium carbonate reacts to form gypsum.

The flue gas treatment device occupies a small area, has good desulfurization and dust removal effects, small flue gas circulation resistance, and low construction and operation costs.

Claims (6)

1. the flue gas device for deep cleaning for efficient desulfurizing and dust collecting, comprise absorption tower, establish slurry pool (7) in absorption tower and be positioned at the smoke absorption district above slurry pool (7), circulating slurry sprinkling device (2) is established at smoke inlet (1) place, it is characterized in that, with dividing plate (14), smoke absorption is separated into the first uptake zone and the second uptake zone being positioned at the first side, uptake zone, the flue gas reentrant pathway (4) being flowed to the second uptake zone by the first uptake zone is established between dividing plate (14) and slurry pool (7), the first slurries spraying layer (3) is established in first uptake zone, the second slurries spraying layer (5) is established in second uptake zone, first slurries spraying layer (3), second slurries spraying layer (5) is all connected with slurry pool (7) by slurry circulating pump (6) with circulating slurry sprinkling device (2), second slurries spraying layer (5) top establishes demister (8) from bottom to top successively, deduster (9) and exhanst gas outlet (15).

2. device as claimed in claim 1, it is characterized in that, also be provided with chilling spray protective device (13) at smoke inlet (1) place, chilling spray protective device (13) is connected with water source (10) by autocontrol valve (12); Between slurry circulating pump (6) and circulating slurry sprinkling device (2), establish flow detector (11), flow detector (11) is connected with autocontrol valve (12).

3. device as claimed in claim 1 or 2, is characterized in that, establish agitating device and oxidation air distribution device in described slurry pool (7).

4. device as claimed in claim 1 or 2, it is characterized in that, described deduster (9) is wet electrical dust precipitator.

5. device as claimed in claim 1 or 2, is characterized in that, the position of described exhanst gas outlet (15) is higher than the position of described smoke inlet (1).

6. device as claimed in claim 1 or 2, is characterized in that, the inwall on described absorption tower establishes line with rubber or lining glass flake anticorrosive coat.