CN205019942U - Compound phase transition dust removal and desulfurization device of flue gas - Google Patents

Abstract

The utility model discloses a flue gas composite phase change dust removal and desulfurization device, which comprises a desulfurization tower (10). The lower part of the side wall of the desulfurization tower (10) is connected with an inlet flue (11), and the upper part of the side wall is connected with an outlet flue Road (12), the inlet flue (11) of the desulfurization tower (10) is provided with a vortex phase changer (13), and the vortex phase changer (13) includes multiple groups of atomizing nozzles (18), multiple groups of mist The atomizing nozzle (18) is symmetrically arranged on the side wall of the inlet flue (11), and the opening direction of the atomizing nozzle (18) faces the inside of the inlet flue (11) and is arranged eccentrically relative to the inlet flue (11), The spray water sprayed out by multiple sets of atomizing nozzles (18) in the vortex phase changer (13) can swirl the flue gas in the inlet flue (11). The utility model utilizes the principle of composite phase transition condensation to condense the supersaturated water vapor on the surface of the fine particles, thereby improving the collection efficiency of the desulfurization tower for the fine particles.

Description

Flue gas composite phase change dust removal and desulfurization device

technical field

The utility model relates to the technical field of air pollution control, in particular to a desulfurization and dust removal tower process and equipment capable of simultaneous efficient desulfurization and dust removal integration, which is suitable for the treatment of industrial flue gas pollutants such as thermal power plants, industrial kilns, and coal-fired boilers.

Background technique

At present, the soot emission of coal-fired boilers is the focus of air pollution control. The main pollutants of coal-fired boiler flue dust are particulate matter, S0 ₂ , NO _x and so on. Among them, particulate pollution, especially fine particulate matter, is the main culprit of atmospheric "smog". These fine particles float over the city for a long time, which not only seriously affects the visibility of the atmosphere, but also absorbs various pollutants (such as Hg, As, Pb and dioxin, etc.), and these particles are also important catalysts for photochemical smog, which seriously endangers human beings health.

The promulgation and implementation of the new "Boiler Air Pollutant Emission Standard" (GB13271-2013) requires that the concentration of boiler smoke and dust emission be reduced to less than 20 mg/Nm ³ , and the ultra-clean emission is required to be less than 5 mg/Nm ³ . Existing boiler flue gas dust removal The technology has been difficult to meet the requirements, and new technology must be adopted to improve the dust removal efficiency of boiler flue gas. The existing process of using phase change coagulation technology to improve dust removal efficiency mainly adopts convective heat transfer technology, that is, adding convective heat exchangers before or after the desulfurization tower to reduce the temperature of the flue gas and increase the water saturation, so that the water molecules in the flue gas from The gaseous state condenses into a liquid state and condenses on the surface of fine particles, increasing the particle size and improving the removal rate of particles.

The convective heat transfer technology is used to adjust the humidity of the flue gas. There are also some problems in this process: 1) The convective heat transfer can only increase the saturation of the moisture in the flue gas by simply reducing the temperature of the flue gas. The adjustment range of moisture saturation in medium is limited. In some special boiler tail gas, the moisture content is low. It is difficult to saturate the moisture simply by lowering the temperature, and the application range is limited; 2) The cooling efficiency of convective heat transfer to reduce the flue gas temperature is limited , because the heat exchange efficiency of this process is not only affected by the nature of the cold source, but also the characteristics of the heat exchange surface material also seriously affect the cooling range of the flue gas. The heat exchange efficiency of conventional heat exchange materials is not high, and a higher water saturation must be achieved 3) The convective heat transfer cooling process requires high heat transfer materials, not only requires a high heat transfer coefficient, but also requires high wear resistance and corrosion resistance, especially in the After the desulfurization tower, the temperature of the flue gas is lower, and the risk of low-temperature corrosion is higher. Special materials are required, and the equipment cost and engineering cost are higher.

Utility model content

The purpose of this utility model is to provide a method of using the principle of composite phase change condensation to condense supersaturated water vapor on the surface of fine particles, to promote the collision and condensation of dust-laden droplets, and to increase the particle size of fine particles in the flue gas. A flue gas composite phase change dust removal and desulfurization device that improves the collection efficiency of the desulfurization tower for fine particles.

In order to achieve the above purpose, the specific technical scheme of a flue gas composite phase change dust removal and desulfurization device of the present invention is as follows:

A flue gas composite phase change dedusting and desulfurization device, comprising a desulfurization tower, the lower part of the side wall of the desulfurization tower is connected with an inlet flue, the upper part of the side wall is connected with an outlet flue, and the inlet flue of the desulfurization tower is provided with a vortex phase changer, The vortex phase changer includes multiple groups of atomizing nozzles, and the multiple groups of atomizing nozzles are symmetrically arranged on the side wall of the inlet flue, and the opening direction of the atomizing nozzles faces the inside of the inlet flue and is arranged eccentrically relative to the inlet flue, The spray water sprayed by multiple groups of atomizing nozzles in the vortex phase changer can swirl the flue gas in the inlet flue.

The advantages of the flue gas composite phase change dust removal and desulfurization device of the present utility model are:

1) The process equipment is simple, the investment is small, the workload is small, the construction period is short, and it is more suitable for the transformation of the existing desulfurization tower;

2) Compared with the traditional convective heat exchange condensation process, the flue gas in this process can be directly humidified while cooling down, and the phase change effect of moisture condensation is more obvious;

3) The spray volume and spray angle of the vortex phase changer are adjustable, and the adjustment range of the moisture saturation in the flue gas is wider, and the adaptability to the characteristics and compounding of the flue gas is also stronger, and the operation control is more flexible and reliable;

4) The cooling water consumption is small, the system resistance increases very little, the operation economy is better, and the equipment is easy to maintain;

5) The process equipment is highly integrated, and it is easy to cooperate with the wet electrostatic precipitator to achieve ultra-low emission of flue gas.

Description of drawings

Fig. 1 is the structural representation of the flue gas composite phase change dedusting and desulfurization device of the present invention;

Fig. 2 is a schematic structural diagram of the vortex phase converter in the present invention.

detailed description

In order to better understand the purpose, structure and function of the utility model, a flue gas composite phase change dust removal and desulfurization device of the utility model will be further described in detail below in conjunction with the accompanying drawings.

As shown in Figures 1 and 2, the flue gas composite phase change dedusting and desulfurization device of the present invention includes a desulfurization tower 10, the lower part of the side wall of the desulfurization tower 10 is connected with an inlet flue 11, and the upper part of the side wall is connected with an outlet flue 12. Wherein, the inlet flue 11 of the desulfurization tower 10 is provided with a vortex phase changer 13, and the vortex phase changer 13 is connected with a clean water tank 14 through a clean water pump.

Further, the vortex phase changer 13 includes multiple groups of atomizing nozzles 18, and the multiple groups of atomizing nozzles 18 are symmetrically arranged on the side wall of the inlet flue 11, and the opening direction of the atomizing nozzles 18 faces the inside of the inlet flue 11 and Relative to the inlet flue 11 eccentrically arranged, the spray water sprayed by multiple groups of atomizing nozzles 18 in the vortex phase changer 13 can make the flue gas in the inlet flue 11 swirl. In addition, it should be noted that the vortex phase changer 13 in the utility model can be designed and installed in the inlet flue 11 of the desulfurization tower 10, and can also be refitted by using the original accident spray layer.

Further, the eccentric angle of the opening direction of the atomizing nozzle 18 in the vortex phase changer 13 relative to the inlet flue 11 is preferably 5-30 degrees, and the pre-spray amount and The eccentric angle of the nozzle is used to maintain the stability of the flue gas swirl and saturation. In addition, in this embodiment, the atomizing nozzle 18 in the vortex phase changer 13 is preferably a single-phase high-pressure nozzle or a two-phase high-pressure nozzle, and the high-pressure atomizing nozzle can improve the atomization effect of the cooling water to ensure the cooling of the flue gas humidify.

As a result, the flue gas generates a swirling flow under the action of the symmetrical eccentric high-pressure spray water, which promotes the contact and mixing of the high-temperature flue gas and the low-temperature atomized water, and strengthens the heat transfer and mass transfer process between the gas-liquid two phases. The collision and agglomeration among the small dusty droplets precipitated by the flow caused the phase change, and promoted the further growth of the particle size of the dusty droplets.

Further, a slurry tank 15 is provided at the bottom of the desulfurization tower 10 . Wherein, a stirring device and an oxidation device are provided in the slurry pool 15. It should be noted that the stirring device in the utility model can be selected but not limited to a side-entry agitator or a top-entry agitator, and the air oxidation device can be selected but not limited to Limited to distributed tube oxidation or oxidation lance oxidation devices.

Further, a desulfurization spray layer 16 is provided in the middle of the desulfurization tower 10 . Wherein, the desulfurization spray layer 16 is arranged above the slurry pool 15, is composed of mechanical nozzles, and is connected to the slurry pool 15 through a slurry pump. In addition, it should be noted that the desulfurization spray layer 16 in the utility model can be arranged in multiple layers according to the flue gas volume and desulfurization efficiency, and an auxiliary spray layer can also be added to reduce "side wall escape" and improve desulfurization and dust removal efficiency.

Further, a high-efficiency demister 17 is installed on the upper part of the desulfurization tower 10 . Among them, the high-efficiency demister 17 can be connected with the clean water tank 14 through a clean water pump. It should be noted that the utility model can adopt a tube type demister, a plate type demister, a roof demister, a fiber plate type, a bed type, etc. High-efficiency demisters or any combination of demisters to improve demisting efficiency.

Further, according to the dust removal efficiency and emission index, the outlet flue 12 of the desulfurization tower 10 can be directly connected to the chimney, so that the clean flue gas can be discharged directly through the chimney. Alternatively, the outlet flue 12 of the desulfurization tower 10 can also be connected to equipment such as a wet electrostatic precipitator to further finely remove dust and achieve ultra-low emission of flue gas.

Referring to Fig. 1 and Fig. 2 below, the working process of the flue gas composite phase change dedusting and desulfurization device of the present invention will be described:

First of all, after the high-temperature raw flue gas is introduced through the inlet flue 11, it first passes through the cooling water injected vertically and eccentrically in the vortex phase changer 13. The contact mixing of flue gas and low-temperature atomized water strengthens the heat transfer and mass transfer process between the gas-liquid two phases, the flue gas is cooled and humidified to reach saturation, and the phase change of water vapor precipitates on the surface of fine particles to form small dust-containing droplets; at the same time, the flue gas The swirling flow of the gas causes the collision and condensation between the small dusty droplets, which promotes the further growth of the particle size of the dusty droplets.

Then, the flue gas carrying the dusty droplets continues to enter the desulfurization tower 10, and is in reverse contact with the desulfurization slurry in the desulfurization spray layer area. During desulfurization, part of the dusty droplets with large particle sizes are captured and removed by the desulfurization slurry. The temperature of the flue gas passing through the desulfurization spray layer 16 continues to decrease, the saturation of the moisture in the flue gas continues to increase, the moisture continues to change and precipitate, and the particle size of the dust-containing droplets continues to increase. After passing through the high-efficiency demister 17, the dust-containing When the droplets are intercepted, the small-sized particles wrapped by the droplets are also removed.

Finally, the clean flue gas after desulfurization and dust removal enters the follow-up wet electrostatic precipitator through the outlet flue 12 of the desulfurization tower 10 for fine dust removal, or directly enters the chimney for discharge.

The flue gas composite phase change dust removal and desulfurization device of the utility model adds a vortex phase changer to the inlet flue of the desulfurization tower, and sprays atomized low-temperature water and high-temperature flue gas to perform mixed heat exchange, while the temperature of the flue gas decreases, As a cooling source, atomized water absorbs heat and turns into a gaseous state, which can directly increase the moisture content in the flue gas, which can not only reduce the temperature of the flue gas, but also increase the absolute moisture content of the flue gas, which can significantly increase the moisture in the flue gas The saturation degree can promote the gaseous water in the flue gas to condense and precipitate with fine particles as crystal nuclei, increase the particle size and quality of the particles, and improve the capture efficiency of the desulfurization tower and subsequent processes for fine particles.

The utility model has been further described above with the help of specific embodiments, but it should be understood that the specific description here should not be interpreted as limiting the essence and scope of the utility model. Various modifications made to the above-mentioned embodiments all belong to the protection scope of the present utility model.

Claims (8)

1. A flue gas composite phase change dedusting and desulfurization device, comprising a desulfurization tower (10), the lower part of the side wall of the desulfurization tower (10) is connected with an inlet flue (11), and the upper part of the side wall is connected with an outlet flue (12), It is characterized in that a vortex phase changer (13) is arranged on the inlet flue (11) of the desulfurization tower (10), and the vortex phase changer (13) includes multiple groups of atomizing nozzles (18), and multiple groups of atomizing nozzles (18) The nozzles (18) are arranged symmetrically on the sidewall of the inlet flue (11), and the opening direction of the atomizing nozzle (18) faces the inside of the inlet flue (11) and is arranged eccentrically relative to the inlet flue (11). The spray water sprayed out by multiple sets of atomizing nozzles (18) in the swirl phase converter (13) can swirl the flue gas in the inlet flue (11). 2. The flue gas composite phase change dust removal and desulfurization device according to claim 1, characterized in that, the opening direction of the atomizing nozzle (18) in the vortex phase changer (13) is relative to the opening direction of the inlet flue (11) The eccentric angle is 5-30 degrees. 3. The flue gas composite phase change dedusting and desulfurization device according to claim 2, characterized in that the atomizing nozzle (18) in the vortex phase changer (13) is a single-phase high-pressure nozzle or a two-phase high-pressure nozzle, and Link to each other with clear water tank (14) by clear water pump. 4. The flue gas composite phase change dedusting and desulfurization device according to claim 1, characterized in that a slurry pool (15) is provided at the bottom of the desulfurization tower (10), and a stirring device and an oxidation device are arranged in the slurry pool (15) . 5. The flue gas composite phase change dust removal and desulfurization device according to claim 4, characterized in that, the middle part of the desulfurization tower (10) is provided with a desulfurization spray layer (16), and the desulfurization spray layer (16) is connected with the The slurry pool (15) links to each other. 6. The flue gas composite phase-change dedusting and desulfurization device according to claim 5, characterized in that, the top of the desulfurization tower (10) is provided with a high-efficiency demister (17), and the high-efficiency demister (17) is connected with a clean water pump Clear water tank (14) links to each other. 7. The flue gas composite phase change dust removal and desulfurization device according to claim 6, characterized in that the outlet flue (12) of the desulfurization tower (10) is connected to a chimney to discharge the flue gas directly. 8. The flue gas composite phase change dust removal and desulfurization device according to claim 6, characterized in that the outlet flue (12) of the desulfurization tower (10) is connected with a wet electrostatic precipitator for fine dust removal of the flue gas.