CN204684801U - A swirl plate dust and fog removal device - Google Patents

Abstract

The utility model discloses a kind of spiral board dedusting demister, comprise multiple dedusting demisting unit, described dedusting demisting unit comprises the overcurrent cylindrical shell of hollow, overcurrent inner barrel is provided with eddy flow, the sub-bottom of described eddy flow is connected with flue gas flow guiding device, described flue gas flow guiding device is fixedly connected with overcurrent cylindrical shell, and described flue gas flow guiding device is provided with purge hole, and described overcurrent cylinder inboard wall is provided with mudhole; Described flue gas flow guiding device is the variable cross-section truncated cone-shaped hollow cylinder of sectional area continuity change, the upper surface of truncated cone-shaped hollow cylinder and eddy flow sub-connection.Flue gas flow guiding device achieves the continuity change of air motion state, and the stability achieving the liquid film of formation is better, effectively prevent the generation of drop reentrainment.Compared with the dedusting demister not having guiding device, distribution of gas state is more even, and effectively reduce the local dip of air-flow through eddy flow, make air flow state more stable, the stability of the liquid film of formation is better.

Description

A swirl plate dust and fog removal device

technical field

The utility model belongs to the field of flue gas purification equipment, in particular to a swirl plate dust and mist removal device.

Background technique

At present, the wet flue gas after limestone wet desulfurization carries more insoluble gypsum and limestone particles in the second time, and the droplet concentration at the outlet of the conventional demister is 75mg/Nm ³ . The soot concentration in the outlet flue gas cannot meet the requirements of the current environmental protection regulations that the soot emission concentration of coal-fired units in key areas is not higher than 20mg/m ³ , let alone meet the requirements of the current ultra-clean emission regulations that the soot content is ≤5mg/Nm ³ requirements.

At present, most of the existing large-scale coal-fired units in China adopt the limestone-gypsum desulfurization process. The dust and fog removal process route of wet desulfurization and clean flue gas that is often used at present is "mist eliminator + wet electrostatic". Using this process route, it can reach The flue gas and dust content at the outlet of the desulfurization tower is less than or equal to 5mg/Nm ³ , but the wet electrostatic precipitator is expensive, consumes a lot of power, and is complicated to operate and maintain. When the main body is arranged separately, it is independent of the wet desulfurization tower body, and a certain site needs to be provided on site. Therefore, for power plants with limited space or compact layout, installation, layout, and maintenance are more difficult.

Chinese patent CN 204208428U discloses a deep dedusting and demisting device, in which there is no flue gas guide device in front of the cyclone, so that when the flue gas flow passes through the secondary cyclone, the flow field is prone to sudden changes and the flow state changes Inhomogeneity can easily affect the stability of the formed liquid film, and it is easy to cause secondary entrainment of droplets, which in turn affects the effect of dust removal and fog removal.

Utility model content

The purpose of this utility model is to overcome the above-mentioned deficiencies in the prior art, to provide a flue gas flow state that is more stable, and the secondary carrying capacity of the liquid droplets is less, which can better realize the saturated humidity containing a large number of liquid droplets after desulfurization. A device for deep dust removal and mist removal of flue gas.

In order to achieve the above object, the utility model adopts the following technical solutions:

A swirl plate dedusting and demisting device, comprising a plurality of dedusting and demisting units, the dedusting and defogging units comprise a hollow flow-through cylinder, a swirl is arranged inside the flow-through cylinder, and the lower part of the swirl is connected to There is a flue gas diversion device, the flue gas diversion device is fixedly connected with the overflow cylinder, the flue gas diversion device is provided with a purge hole, and the inner wall of the overflow cylinder is provided with a sewage hole; The flue gas guiding device is a variable-section frustum-shaped hollow cylinder whose cross-sectional area continuously changes, and the upper end surface of the frustum-shaped hollow cylinder is connected with the swirler.

The swirler includes a central fixed cylinder, a plurality of guide vanes and an outer surrounding plate, and the guide vanes are radially and vertically distributed in the annular area between the outer wall of the central fixed cylinder and the inner wall of the outer surrounding plate according to a set elevation angle.

The central fixing cylinder is a cylindrical cylinder with a closed end and a hollow interior.

The outer surrounding plate is a hollow cylindrical structure.

The diameter of the upper surface of the flue gas guiding device is the same as the outer diameter of the outer surrounding plate of the swirler, and the bottom of the outer surrounding plate is fixedly connected to the upper part of the flue gas guiding device.

The diameter of the lower end cylinder of the smoke guide device is 3-5mm smaller than the inner diameter of the flow-through cylinder, and a 3-5mm annular groove is formed between the root of the smoke guide device and the flow-through cylinder. The liquid film formed on the inner wall of the overflow cylinder flows into the annular groove by gravity and is discharged through the drain hole, which maintains the stability of the liquid film thickness.

The lower end of the flue gas diversion device is connected with the connecting flange of the diversion device, through which the connecting flange of the diversion device is welded together with the overflow cylinder; the upper end of the overflow cylinder is connected with the reverse flange of the overflow cylinder , the flow-through cylinder connecting anti-flange between adjacent dust and mist removal units and the connecting flange of the flow guiding device are connected together.

The drain holes are divided into upper drain holes and lower drain holes. The opening direction of the upper drain holes is tangent to the inner wall of the flow-through cylinder and is the same as the swirling direction of the flue gas. The opening of the lower drain holes is located at In the annular groove between the root of the flue gas diversion device and the overflow cylinder, the lower drain hole is perpendicular to the overflow cylinder wall, and the liquid film formed on the inner wall of the overflow cylinder is continuously discharged through the upper and lower layers of drain holes.

The upper drain hole and the lower drain hole are evenly arranged on the wall of the overflow cylinder along the circumferential direction.

The purge holes are arranged at the root of the flue gas diversion device, and the purge holes are concentric with the sewage discharge holes of the lower layer, and are evenly distributed along the circumference of the flue gas diversion device.

The number of the purge holes can be adjusted according to the dust concentration of the flue gas at the inlet of the dust and mist eliminator, and the number is generally 12-18. The aperture of the purging hole should not be too large, preferably 5 mm.

There is a liquid retaining groove at the upper drain hole on the inner wall of the overflow cylinder, and the upper drain hole is located in the liquid retaining groove; the liquid retaining groove is a groove with a set height and a set depth, and its parameters such as height and depth It is determined according to the flue gas flow rate and flow rate, so as to obtain the maximum liquid holding capacity.

The installation setting elevation angle of the guide vanes is 25°-45°.

The working principle of the swirl plate dedusting and mist removal device of the utility model is: when the saturated wet flue gas passes through the swirl from bottom to top, the flue gas diversion device realizes the continuous change of the airflow movement state and the gas distribution state. Excessive stability, the horizontally moving saturated wet flue gas transforms into a high-speed rotating state, during which, the fine droplets reunite and grow into larger droplets during the turbulent collision process, using the separation inertia of the liquid droplets and smoke carried in the flue gas The difference is that the grown liquid droplets and dust particles in the flue gas are thrown onto the liquid film on the inner wall of the cyclone flue to capture the liquid droplets and smoke dust. The height and thickness of the liquid film are maintained by the liquid retaining tank and the sewage hole.

The beneficial effects of the utility model are:

1. The effect of dust removal and fog removal is good; under normal operating conditions, the fog droplet content at the outlet of the desulfurization tower can be ≤10mg/Nm ³ , and the total concentration of smoke at the inlet (including gypsum and limestone particles carried by the secondary) ≤30mg/Nm ³ , the outlet The soot concentration can be reduced to less than 10mg/Nm ³ , combined with high-efficiency nozzle and tray technology, the outlet soot concentration can be reduced to less than 5mg/Nm ³ , meeting the current ultra-low emission requirements. Low energy consumption, the single-layer running resistance of the device is ≤60pa, and the double-layer running resistance is ≤120pa. The dust and fog removal method of this device can replace the conventional "mist eliminator + wet electrostatic" process.

2. The flue gas diversion device realizes the continuous change of the airflow movement state, realizes better stability of the formed liquid film, and effectively prevents the secondary entrainment of liquid droplets. Compared with the dust and mist eliminator without flow guide device, the gas distribution state is more uniform, which effectively reduces the local disturbance of the air flow passing through the swirler, makes the flow state of the air flow more stable, and the stability of the formed liquid film is better.

3. Low investment cost, good operation stability, no risk of fouling and blockage, and achieve deep dedusting and demisting of saturated wet flue gas after desulfurization at low investment and operating costs.

4. There is no additional installation space requirement, and the demister can be removed and installed directly.

5. The purge hole set by the flue gas diversion device can continuously purge the bottom drain hole, which effectively solves the problem of blockage of the drain hole during operation.

Description of drawings

Fig. 1 is the structural schematic diagram of the swirl plate dedusting and demisting device of the present invention;

Fig. 2 is a structural schematic diagram of the swirler of the swirl plate dust removal and mist removal device of the present invention;

Fig. 3 is A-A direction sectional view in Fig. 1;

In the figure, 1 is the overflow cylinder, 2 is the swirl, 3 is the flue gas diversion device, 4 is the lower drain hole, 5 is the connecting flange of the diversion device, and 6 is the reverse flange connected to the overflow cylinder. 7 is a liquid retaining tank, 8 is an upper drain hole, 9 is a central fixed cylinder, 10 is a guide vane, 11 is an outer surrounding plate, and 12 is a purge hole.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

The swirl plate dedusting and demisting device of the utility model is installed above the spray layer in the desulfurization absorption tower, and the saturated wet flue gas after desulfurization containing a large number of liquid droplets passes through the flow guide device from bottom to top through the flow section of the swirl. The diversion effect can realize the stability of flue gas flow state. Then the small droplets reunite and grow into larger droplets during the collision process in the swirl. Using the separation inertia of the droplets and dust carried in the flue gas and the flue gas is different, the grown droplets are different from the particles in the flue gas. Dust particles are thrown onto the liquid film flowing on the inner wall of the cylinder to capture liquid droplets and smoke. The flue gas velocity before entering the swirl plate dedusting and demister is 3.5m/s-5m/s, and the average residence time of the flue gas in the swirling plate dedusting and demister is 0.08-0.42s.

The overflow cylinder body of the device of the utility model is a flue gas flow passage part of the dust removal and mist removal device, and a non-metallic cylindrical hollow cylinder body with smooth walls and no closed ends placed along the flow direction of the flue gas.

The flue gas diversion device of the utility model is a diversion device arranged at the lower part of the swirler to maintain a suitable air flow distribution state, realize a smooth transition of the air flow movement state, further maintain a suitable liquid film stability, and prevent liquid droplets secondary carry.

The swirl of the utility model is an air flow guiding part that converts the horizontal motion of the flue gas flow into a high-speed rotary motion, and the swirl is composed of a central fixed cylinder, guide vanes, and an outer surrounding plate. The guide vanes in the vortex are vertically installed radially and vertically in the annular area between the outer wall of the central fixed cylinder and the inner wall of the outer surrounding plate according to a certain elevation angle.

As shown in Figures 1-2, the swirl plate dust and fog removal device includes multiple dust and fog removal units, and each dust and fog removal unit includes at least one overflow cylinder 1, a first-stage swirler 2, a first-stage The flue gas diversion device 3, one layer of liquid retaining tank 7 and two upper and lower layers of sewage outlets.

A liquid retaining tank 7 is arranged on the overflow cylinder, and a liquid film with a stable liquid holding capacity is formed on the inner wall of the overflow cylinder 1 through the liquid retaining tank 7. The liquid retaining tank 7 is a liquid film holding capacity control device for dust and mist removal devices. It is a groove-shaped device with a certain depth and height. The parameters such as height and depth are determined according to the flow rate and flow rate of the flue gas, so as to obtain the maximum liquid holding capacity.

According to parameters such as flue gas volume, dust removal and mist removal efficiency, one to three layers of swirlers 2 are selected inside the overflow cylinder 1, and the swirlers are composed of a central fixed cylinder 9, guide vanes 10, and outer surrounding plates 11. The guide vanes 10 are vertically installed radially and vertically on the annular area between the outer wall of the central fixed cylinder 9 and the inner wall of the outer surrounding plate 11 according to a certain elevation angle. The outer surrounding plate 11 and the guide vane 10 are connected by welding. The number and inclination angle of the guide vanes 10 are adjusted according to parameters such as flue gas volume, dust and mist removal efficiency, and the like. The central fixed cylinder 9 is a cylindrical cylinder with a closed end and a hollow interior. The installation elevation angle of the guide vanes in the swirler is 25-45°, and the number and installation elevation angle of the swirl sub-blades are 8.5-12.5m/s to meet the particle velocity of the airflow at the outlet of the swirler.

A layer of flue gas guiding device 3 is arranged on the lower part of the swirler 2 , and the upper part of the flue gas guiding device 3 is welded to the outer surrounding plate 11 of the swirler 2 . The height of the flue gas guiding device 3 is determined according to the resistance requirements of the system, the size of the top end surface of the flue gas guiding device 3 is determined according to the size of the swirler, and the diameter of the cylindrical surface at the bottom of the flue gas guiding device The inner diameter is 3-5mm smaller, and a 3-5mm annular groove is formed between the root of the flue gas guide device and the overflow cylinder, and the liquid film formed on the inner wall of the overflow cylinder flows into the annular groove by gravity and passes through the sewage. Hole discharge maintains the stability of the liquid film thickness. The lower end of the flue gas diversion device 3 is connected to the connecting flange 5 of the diversion device, and the connecting flange 5 of the diversion device is welded together with the overflow cylinder 1; the upper end of the overflow cylinder 1 is connected to the reverse method Lan 6, the flow-through cylinder connection between adjacent dedusting and mist removal units, the anti-flange 6 and the flow guide device connecting flange 5 are connected together.

The flue gas diversion device 3 is a variable-section frustum-shaped cylinder with a continuous change in cross-sectional area. The swirling radius of the airflow gradually decreases. According to the centripetal force formula: f=mv/r, f remains unchanged, m remains unchanged, r decreases, and v increases, so the particle velocity of the airflow also increases accordingly. The smoke guide device The continuous change of the airflow movement state is realized, the excessive stability of the gas distribution state is realized, and the occurrence of local eddies is avoided. Compared with the dust and mist eliminator without flow guide device, the airflow distribution state is more uniform.

In order to ensure the thickness of the liquid film in the dust and mist removal device, two upper and lower layers of drain holes are also provided. The upper layer of drain holes 8 are opened inside the liquid retaining tank 7, and the direction of the holes is tangent to the inner wall of the overflow cylinder 1 and swirls with the flue gas. The same direction. The drain holes 4 in the lower layer are opened in the annular groove between the root of the flue gas diversion device 3 and the overflow cylinder 1, and are perpendicular to the wall of the overflow cylinder 1. Flow tube wall.

In order to effectively solve the problem of clogging of the dust and mist eliminator during operation, purge holes 12 are also set at the root of the flue gas guide device 3. The purge holes 12 are concentric with the drain holes in the lower layer of the overflow cylinder, and are evenly distributed along the circumference of the guide device. The lower drain hole can be continuously purged. The number of purge holes can be adjusted according to the dust concentration of the flue gas at the inlet of the dust and mist eliminator, and the number is generally 12-18. The diameter of the purge hole should not be too large, preferably 5mm.

Although the specific implementation of the utility model has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the utility model. Those skilled in the art should understand that on the basis of the technical solution of the utility model, those skilled in the art do not need to Various modifications or deformations that can be made with creative efforts are still within the protection scope of the present utility model.

Claims (10)

1. A swirl plate dedusting and demisting device is characterized in that it comprises a plurality of dedusting and demisting units, and said dedusting and demisting unit comprises a hollow overflow cylinder, and the inside of the overflow cylinder is provided with a swirl, so The lower part of the swirler is connected with a flue gas guiding device, and the flue gas guiding device is fixedly connected with the overflow cylinder, and the flue gas guiding device is provided with a purge hole, and the inner wall of the overflow cylinder is provided with There are sewage holes; the flue gas diversion device is a variable cross-section frustum-shaped hollow cylinder whose cross-sectional area continuously changes, and the upper end surface of the frustum-shaped hollow cylinder is connected with the swirl. 2. The swirl plate dust and mist removal device according to claim 1, wherein the swirl includes a central fixed cylinder, a plurality of guide vanes and an outer surrounding plate, and the guide vanes are arranged according to a set elevation angle Radially and vertically distributed in the annular area between the outer wall of the central fixed cylinder and the inner wall of the outer surrounding plate. 3. The swirl plate dedusting and demisting device according to claim 2, characterized in that, the central fixed cylinder is a cylindrical cylinder with a closed end and a hollow interior, and the installation setting elevation angle of the guide vanes is 25° °-45°. 4. The swirl plate dust and mist removal device according to claim 2, wherein the outer surrounding plate is a hollow cylindrical structure. 5. The swirling plate dedusting and demisting device according to claim 1, wherein the diameter of the upper end surface of the flue gas guiding device is the same as the outer diameter of the outer surrounding plate of the swirler, and the outer surrounding The bottom of the plate is fixedly connected with the upper part of the flue gas guiding device. 6. The swirl plate dedusting and demisting device according to claim 1, characterized in that, the diameter of the cylinder body at the lower end surface of the flue gas guiding device is 3-5mm smaller than the inner diameter of the overflow cylinder body, and in the flue gas A 3-5mm annular groove is formed between the root of the deflector and the flow-passing cylinder. 7. The swirl plate dust and mist removal device according to claim 1, characterized in that, the lower end of the flue gas guide device is connected with a guide device connecting flange, through which the guide device connects the flange and the overflow cylinder welded together; the upper end of the overflow cylinder is connected with an overflow cylinder connection anti-flange, and the overflow cylinder connection anti-flange between adjacent dust and mist removal units is connected with the flow guide device connection flange. 8. The swirl plate dedusting and mist removal device according to claim 1, wherein the drain hole is divided into an upper drain hole and a lower drain hole, and the opening direction of the upper drain hole is in line with the inner wall of the overflow cylinder. Tangential to and in the same direction as the swirling flow of the flue gas, the opening of the lower drain hole is set in the annular groove between the root of the flue gas guide device and the overflow cylinder, and the lower drain hole is perpendicular to the wall of the overflow cylinder. 9. The swirl plate dedusting and demisting device according to claim 8, characterized in that, the upper drain hole and the lower drain hole are evenly arranged on the wall of the overflow cylinder along the circumferential direction; the inner wall of the overflow cylinder The upper drain hole is provided with a liquid retaining groove, and the upper drain hole is located in the liquid retaining groove; the liquid retaining groove is a groove with a set height and a set depth. 10. The swirl plate dedusting and mist removal device according to claim 8, characterized in that, the purge hole is arranged at the root of the flue gas guide device, and the purge hole is concentric with the lower drain hole, along the direction of the flue gas guide device. Circumferentially evenly distributed.