CN109939530B - Particle coagulation device for low-temperature plasma charged ultrasonic atomized liquid drops - Google Patents

Abstract

The present invention is a particle agglomeration device for low-temperature plasma charged ultrasonic atomized droplets, comprising an inlet gradually expanding section, an atomizing charging section and a turbulent condensing section arranged in sequence along the flue gas flow direction; the atomizing charging section includes an atomizing charging section Charge tube; the atomization charge tube includes an intermediate pipe with an ultrasonic atomization droplet inlet and a plurality of branch pipes connected to both sides of the intermediate pipe; the branch pipe includes a charging shell inserted in the intermediate pipe , a flow plug set at the connection end of the charging shell, a fixed end cover set at the free end; a plurality of charged droplet nozzles are arranged above the charging shell along the flue gas flow direction, and a blocking medium is coaxially arranged in the charging shell , the two ends of the blocking medium are respectively fixed on the flow plug and the fixed end cover, and the blocking medium is provided with a high-voltage electrode inserted through the fixed end cover; the charging shell is connected with the ground wire to form a discharge high-voltage circuit; the blocking medium and the The gap between the charged shells for the circulation of atomized droplets; the turbulent condensation section includes the shell and the vortex-generating element.

Description

A particle agglomeration device for low temperature plasma charged ultrasonic atomized droplets

technical field

The invention relates to the technical field of emission control of particulate matter in coal-fired industries, in particular to a particle agglomeration device for low-temperature plasma charged ultrasonic atomized droplets.

Background technique

The fine particulate matter PM _2.5 (particles with a kinetic diameter of less than 2.5 μm) emitted by the coal-burning industry has an important impact on the atmospheric environment and human health. Traditional industrial dust removal equipment (such as electrostatic precipitator, bag filter, wet electrostatic precipitator, etc.) has a penetration window in the range of 0.1 to 2 μm due to different dust removal mechanisms for particles with different particle sizes. The low efficiency causes a large amount of fine particles to be emitted. The addition of a particle coagulation pretreatment device based on the traditional dust removal technology is a new technical means that can effectively solve the difficult removal of fine particles. Coagulation and turbulent coagulation, etc. Different agglomeration methods have certain agglomeration effects on fine particles, but only a single agglomeration technology still has the shortcomings of limited removal of fine particles and insufficient reliability. Particulate matter has important value in scientific research and development and industrial application.

Patent document with publication number CN1121908C discloses a dust removal device based on bipolar charging to promote particle agglomeration. The device is composed of an air inlet channel, a discharge coagulation section, an air outlet channel and a dust removal component connected in sequence. The discharge channel includes at least one set of discharge channel pairs, and each pair of discharge channels can generate charges of opposite polarities to the particles, thereby promoting The particles collide and agglomerate and intensify the effective removal in the dedusting component. The device has a clear principle and a simple structure, but only uses electrocoagulation to promote particle agglomeration without considering the power discharge characteristics and complex structure processing, so the agglomeration effect is limited.

The patent document with the publication number of CN108412534A discloses a coal mine dust removal device based on ultrasonic atomization and condensation. Its main components are an ultrasonic atomizer and a condensation chamber arranged with an ultrasonic oscillator. A certain range, and then the collision and agglomeration of particles and droplets are promoted in the agglomeration chamber through ultrasonic vibration, and then the particles are removed in the dust collector. The device is mainly used in coal mine dust removal, the purpose is to reduce the gas dust concentration below the limit concentration of dust explosion, but the mixed flow of ultrasonic atomized droplets and high concentration dust gas can easily cause pipeline deposition and blockage, so long-term operation is difficult Stable and effective agglomeration of particulate matter.

SUMMARY OF THE INVENTION

Aiming at the problems existing in the prior art, the present invention provides a particle agglomeration device for low-temperature plasma charged ultrasonic atomized droplets. Effectively improve the removal efficiency of dust removal device for fine particles.

The present invention is achieved through the following technical solutions:

A particle agglomeration device for low-temperature plasma charged ultrasonic atomized droplets, comprising an inlet gradually expanding section, an atomizing charging section and a turbulent condensing section arranged in sequence along the flue gas flow direction;

The atomization charge section includes an atomization charge tube; the atomization charge tube includes an intermediate pipe with an ultrasonic atomization droplet inlet and a plurality of branch pipes connected to both sides of the intermediate pipe; the branch pipes include The charging shell plugged into the intermediate pipe, the flow plug set at the connecting end of the charging shell, and the fixed end cover set at the free end; a plurality of charging droplet nozzles are arranged above the charging shell along the flue gas flow direction , a blocking medium is coaxially arranged in the charging shell, the two ends of the blocking medium are respectively fixed on the flow plug and the fixed end cover, and the blocking medium is provided with a high-voltage electrode inserted through the fixed end cover; the charging shell is connected to the ground Line connection to form a discharge high-voltage circuit; a gap between the blocking medium and the charged shell for the circulation of atomized droplets;

The turbulent condensing section includes a casing and a vortex-generating element fixedly arranged in the casing.

Preferably, an anti-wear tile is provided on the windward side of the atomizing charge tube.

Preferably, the charging case is provided with a ground wire hole for connecting the ground wire, and the fixed end cover is provided with a high voltage wire hole for the wire of the high voltage electrode to pass through.

Preferably, a mesh electrode is sleeved on the blocking medium, and there is an air gap between the blocking medium and the mesh electrode for the circulation of atomized droplets; the mesh electrode is connected to the ground wire to form a discharge high-voltage circuit.

Preferably, the two ends of the flow plug are respectively fixed in the charging case, and the middle is used to support the blocking medium, and the maximum cross-sectional area along the radial direction at this section accounts for 40-60% of the flow cross-sectional area.

Preferably, the branch pipes are symmetrically arranged on both sides of the intermediate pipe; the intermediate pipe and each branch pipe respectively form an inclination angle of 5-15° with the horizontal plane.

Preferably, the particle size of the charged atomized droplets is 1-10 μm; the atomization amount in each branch pipe is 0.05-1 kg/h.

Preferably, the flow plug and the fixed end cap are both made of an insulating material selected from polytetrafluoroethylene, epoxy resin, quartz and ceramics.

Preferably, the blocking medium is made of polytetrafluoroethylene, epoxy resin, quartz or ceramics to make an insulating circular tube, and the thickness of the tube wall is 5-15 mm; the high-voltage electrode is a metal circular tube made of stainless steel or copper The rod has a diameter of 5-10 mm, and the applied voltage is 5-20 kV alternating current.

Preferably, the radial dimension of the gap between the blocking medium and the charged housing for the atomized droplets to circulate is 5-20 mm.

Preferably, the vortex generating elements are arranged in a staggered array; their cross-sectional shape is a triangle, a semicircle or a T shape, one corner of the triangle is set downward, the arc of the semicircle is downward, or the vertical end of the T shape is set downward, and the A polytetrafluoroethylene film is attached to the leeward side along the flue gas flow direction.

Compared with the prior art, the present invention has the following beneficial technical effects:

The invention is based on the principle of multi-field synergistic agglomeration of fine particles by electrocoagulation, atomization agglomeration and turbulent agglomeration, and has essential enhancement and improvement for the agglomeration effect of fine particles. The device innovatively applies low-temperature plasma to ultrasonically atomized droplets, which can effectively avoid the abrasion and contamination of the charged device by flue gas particles, and at the same time avoid the damage to the charged electrode caused by the adhesion and agglomeration of droplets and particles. The low-temperature plasma atomization charged electrode is based on the principle of dielectric barrier discharge, the ingenious design of the single-dielectric high-voltage electrode, the spacing arrangement of the atomizing nozzles, the flow plugs and fixed end caps at both ends of the electrode, and the inclined arrangement of the tubular electrode, etc. It solves various problems such as surface flashover, electrode fixation, insulation protection, and fluid drainage, and further ensures the droplet charging effect and the fine particle agglomeration effect while ensuring the stability of operation. The device is compact in structure, low in cost, has distinct theoretical innovation and good cohesion effect, can be operated in industrial sites for a long time, and has great application and promotion value.

Description of drawings

FIG. 1 is a schematic diagram of the overall structure of the particle agglomeration device according to the present invention.

FIG. 2 is a schematic diagram of the overall structure of the atomized charging section according to the present invention.

FIG. 3 is a schematic structural diagram of the atomized charged electrode according to the present invention.

FIG. 4 is a schematic structural diagram of the atomized charged electrode (including the mesh electrode) according to the present invention.

FIG. 5 is a schematic diagram of the discharge corona effect of the atomized charged electrode according to the present invention.

In the figure: air inlet gradually expanding section 1, atomizing charging section 2, turbulent agglomeration section 3, vortex generating element 31, atomizing charging electrode 21, anti-wear shoe 22, intermediate pipe 211, flow plug 212, Charged droplet nozzle 213 , blocking medium 214 , high voltage electrode 215 , ground wire hole 216 , fixed end cap 217 , high voltage wire hole 218 , charging shell 219 , mesh electrode 220 .

Detailed ways

The present invention will be further described in detail below in conjunction with specific embodiments, which are to explain rather than limit the present invention.

The present invention is a particle agglomeration device for low-temperature plasma charged ultrasonic atomized droplets, which is sequentially arranged with an inlet gradually expanding section 1, an atomizing charging section 2 and a turbulent condensing section 3 along the flue gas flow direction. The atomizing charging section 2 includes an atomizing charging tube 21 and an anti-wear tile 22, which can be used to perform low-temperature plasma charging on the atomized droplets generated by ultrasonic atomization, and the charging voltage is 5-20 kV. The particle size of the charged atomized droplets is 1 to 20 μm; the atomized charge tube is in a tree-like branched tubular structure, and the charged area is, from inside to outside, the high-voltage electrode 215, the blocking medium 214, the charge gap, The mesh electrode 220 and the charging shell 219; the high voltage electrode 215 is a metal round rod with a diameter of 5-10 mm, the blocking medium 214 is an insulating round tube with a wall thickness of 5-15 mm, and the charging gap is 5-20 mm in radial dimension. The turbulent condensing section 3 includes a series of vortex-generating elements 31 arranged in the casing, and its cross-sectional shape is a triangle, a semicircle, a T-shape, etc., and a polytetrafluoroethylene film is attached to the leeward surface to promote the flue gas. Disturbance and synergistic atomization of charged agglomerated particulate matter. The invention has good effect on particle agglomeration, strong stability and low cost, can be used for particulate matter discharged from coal-fired boilers, industrial furnaces and the like, and is suitable for industrial sites.

The present invention is a particle agglomeration device for low-temperature plasma charged ultrasonic atomized droplets. The inlet gradually expanding section 1, the atomizing charging section 2 and the turbulent condensing section 3 are sequentially arranged along the flue gas flow direction; The electric section 2 is composed of an atomizing charge tube 21 and an anti-wear tile 22; the atomizing charge tube 21 includes an intermediate pipe 211, a flow plug 212, a charged droplet nozzle 213, a blocking medium 214, a high voltage The electrode 215, the ground wire hole 216, the fixed end cover 217, the high voltage wire hole 218, the charging shell 219 and the mesh electrode 220; The housing of the vortex generating element 31 is fixed.

Among them, the atomization charging section 2 is used to perform low-temperature plasma charging on the atomized droplets at the inlet of the ultrasonic atomized droplets, and the charged atomized droplets have a particle size of 1-10 μm; The charging tube 21 is a tree-like branched tubular structure arranged at a certain interval. The intermediate joint tube 211 and each branched branch tube respectively have an inclination angle α of 5-15° with the horizontal plane, all of which are upwards along the flow direction of the ultrasonic atomized droplets inside the tube. Inclined, that is, the end of each pipe is higher than the beginning; the amount of atomization through each branch pipe is 0.05-1kg/h.

The material of the flow plug 212 and the fixed end cover 217 is an insulating material such as polytetrafluoroethylene, epoxy resin, quartz or ceramic, etc., and the function is to fix the blocking medium 214 and the high voltage electrode 215; The head 212 is fixed to the charging shell 219, and its maximum cross-sectional area in the radial direction accounts for 40-60% of the flow cross-sectional area, and does not affect the normal flow of the atomized droplets.

The material of the blocking medium 214 is a kind of insulating round tube in polytetrafluoroethylene, epoxy resin, quartz or ceramics, and the thickness of the tube wall is 5-15mm; the material of the high-voltage electrode 215 is one of stainless steel or copper. A metal round bar with a diameter of 5-10mm and an applied voltage of 5-20kV alternating current.

There is a gap between the blocking medium 214 and the charging shell 219 for the atomized droplets to circulate, and the radial dimension of the gap is 5-20 mm.

When the mesh electrode 220 does not exist, the charging shell 219 is made of metal materials such as stainless steel or copper, and is connected to the ground wire through the ground wire hole 216 to form a discharge high-voltage circuit; when the mesh electrode 220 exists, The material of the charging shell 219 can be a metal material or a non-metal material, and the mesh electrode 220 is connected to the ground wire through the ground wire hole 216 to form a discharge high-voltage circuit.

The vortex generating element 3 has a cross-sectional shape of a triangle, a semicircle, a T shape, etc., and the leeward surface along the flue gas flow direction is attached with a polytetrafluoroethylene film, in order to promote flue gas disturbance and strengthen the aggregation of fine particles. deposited on the surface of the vortex-generating element.

Specifically, as shown in Figure 1, the device of the present invention is used for the coagulation and removal of fine particles in front of a kiln head dust bag filter in a 3800t/d cement plant. Turbulent Condensation Section 3. The gradually expanding section 1 is used to control the flow rate of the flue gas in the coagulator, so that the mixing effect of the particles and the ultrasonic atomized droplets charged by the low-temperature plasma is the best within a certain flow rate range. Best results. The fine particles mentioned in the present invention specifically refer to 0.1-1 μm, that is, the particle size range in which the removal efficiency of particles is low due to the different removal mechanisms of the bag filter for different particle sizes.

The overall structure of the atomizing charging section 2 is shown in FIG. 2 , which is composed of an atomizing charging tube 21 and an anti-wear tile 22 , which is used to perform low-temperature plasma charging on the ultrasonic atomized liquid droplets. The atomization charge tube is composed of 8 branch pipes and 1 intermediate pipe. Both the branch pipe and the intermediate pipe are at an included angle of 6° with the horizontal plane, which is used to remove the effusion generated by the atomized droplets; The amount of atomization is controlled at 0.1-0.2kg/h to avoid a large amount of liquid accumulation due to excessive atomization. The atomizing charge tube 21 includes an intermediate pipe 211, a flow plug 212, a charged droplet nozzle 213, a blocking medium 214, a high-voltage electrode 215, a ground wire hole 216, a fixed end cap 217, a high-voltage wire hole 218, and a charging shell body 219 and mesh electrode 220.

In this embodiment, as shown in FIG. 4, the mesh electrode 220 is used as the grounding low-voltage terminal, and the temperature of the dust-laden flue gas is 95°C. Therefore, epoxy resin with a temperature resistance of 180°C is used as the flow plug 212 and the fixed end cap. 217 and the processing material of the charging case 219. The mesh electrode 220 is made of 304 stainless steel, with a mesh number of 20 and a wire diameter of 1 mm, and is closely attached to the inner wall of the charging case 219 . The blocking medium 214 is made of a ceramic tube with a wall thickness of 8 mm, which can withstand the local high temperature formed during the low-temperature plasma discharge process; there is an air gap between the blocking medium 214 and the mesh electrode 220 for the circulation of atomized droplets, and the gap distance is 8mm. The high-voltage electrode 215 is made of 304 stainless steel bar, the diameter is 6mm, the charging voltage is 8-20kV alternating current, and the discharge power of a single branch tube is 50-300W. The two ends of the flow plug 212 are fixed to the charging shell 219, and the blocking medium 214 and the high-voltage electrode 215 are supported in the middle. The maximum cross-sectional area along the radial direction at this section accounts for 50% of the flow cross-sectional area, which can ensure the ultrasonic wave. Liquefied droplets circulate normally.

During use, the particle agglomeration device sprays the ultrasonic atomized droplets charged by the low-temperature plasma into the flue. The liquid droplets undergo turbulent collision and agglomeration in the turbulent agglomeration section 3 . A triangular vortex-generating element 31 is used in the turbulent agglomeration section 3, and a 2mm fluoroplastic film is attached to the leeward surface to strengthen the agglomeration effect of fine particles. The stable discharge power of the single-branch atomizing charged electrode is 200W, and the discharge corona effect is shown in Figure 5; the preliminary experimental results show that when the atomizing charging section 2 is not running, only the vortex generating element 31 is used to agglomerate PM _2.5 . The efficiency is about 12%, while the agglomeration efficiency of the particle agglomeration device for PM _2.5 increases to about 35% when the atomizing charge section 2 is operating normally.

Claims (9)

1. A particle coagulation device for low-temperature plasma charged ultrasonic atomized liquid droplets is characterized in that: comprises an inlet divergent section (1), an atomization charge section (2) and a turbulent flow condensation section (3) which are sequentially arranged along the flow direction of flue gas;

the atomization charging section (2) comprises an atomization charging pipe (21); the atomization charging pipe (21) comprises a middle connecting pipe (211) provided with an ultrasonic atomization dropping liquid inlet and a plurality of branch pipes communicated with the two sides of the middle connecting pipe (211); the branch pipe comprises a charged shell (219) inserted in the middle connecting pipe (211), a through-flow plug (212) arranged at the connecting end of the charged shell (219), and a fixed end cover (217) arranged at the free end; a plurality of charged liquid drop nozzles (213) are arranged above the charged shell (219) along the flow direction of flue gas, a blocking medium (214) is coaxially arranged in the charged shell (219), two ends of the blocking medium (214) are respectively fixed on the through-flow plug (212) and the fixed end cover (217), and a high-voltage electrode (215) inserted through the fixed end cover (217) is arranged in the blocking medium (214); the charging shell (219) is connected with the ground wire to form a discharging high-voltage loop; a gap through which atomized liquid droplets can flow is formed between the blocking medium (214) and the charged shell (219);

the turbulent condensation section (3) comprises a shell and a vortex generating element (31) fixedly arranged in the shell.

2. The apparatus according to claim 1, wherein the apparatus comprises: the charging shell (219) is provided with a grounding wire hole (216) for connecting a ground wire, and the fixed end cover (217) is provided with a high-voltage wire hole (218) for a lead of the high-voltage electrode (215) to pass through.

3. The apparatus according to claim 1, wherein the apparatus comprises: the branch pipes are symmetrically arranged at two sides of the middle connecting pipe (211); the intermediate connecting pipe (211) and each branch pipe form an inclination angle of 5-15 degrees with the horizontal plane respectively.

4. The apparatus according to claim 1, wherein the apparatus comprises: the particle size of the charged atomized liquid drops is 1-10 mu m; the atomization amount in each branch pipe is 0.05-1 kg/h.

5. The apparatus according to claim 1, wherein the apparatus comprises: the through-flow plug (212) and the fixed end cover (217) are both made of an insulating material selected from polytetrafluoroethylene, epoxy resin, quartz and ceramic.

6. The apparatus according to claim 1, wherein the apparatus comprises: the barrier medium (214) is an insulating circular tube made of polytetrafluoroethylene, epoxy resin, quartz or ceramic, and the thickness of the tube wall is 5-15 mm; the high-voltage electrode (215) is a metal round bar made of stainless steel or copper, the diameter of the metal round bar is 5-10 mm, and the applied voltage is 5-20 kV alternating current.

7. The apparatus according to claim 1, wherein the apparatus comprises: the size of a gap between the blocking medium (214) and the charged shell (219) for the atomized liquid droplets to flow is 5-20 mm along the radial direction.

8. The apparatus according to claim 1, wherein the apparatus comprises: the vortex generating elements (31) are arranged in a staggered array; the section of the smoke-absorbing plate is triangular, semicircular or T-shaped, one angle of the triangle is arranged downwards, the cambered surface of the semicircle is arranged downwards or the vertical end of the T-shaped is arranged downwards, and a polytetrafluoroethylene film is attached to the lee side of the smoke-absorbing plate along the flow direction of smoke.

9. A particle coagulation device for low-temperature plasma charged ultrasonic atomized liquid droplets is characterized in that: comprises an inlet divergent section (1), an atomization charge section (2) and a turbulent flow condensation section (3) which are sequentially arranged along the flow direction of flue gas;

the atomization charging section (2) comprises an atomization charging pipe (21); the atomization charging pipe (21) comprises a middle connecting pipe (211) provided with an ultrasonic atomization dropping liquid inlet and a plurality of branch pipes communicated with the two sides of the middle connecting pipe (211); the branch pipe comprises a charged shell (219) inserted in the middle connecting pipe (211), a through-flow plug (212) arranged at the connecting end of the charged shell (219), and a fixed end cover (217) arranged at the free end; a plurality of charged liquid drop nozzles (213) are arranged above the charged shell (219) along the flow direction of flue gas, a blocking medium (214) is coaxially arranged in the charged shell (219), two ends of the blocking medium (214) are respectively fixed on the through-flow plug (212) and the fixed end cover (217), and a high-voltage electrode (215) inserted through the fixed end cover (217) is arranged in the blocking medium (214);

the barrier medium (214) is sleeved with a mesh electrode (220), and an air gap for atomized liquid to flow through is formed between the barrier medium (214) and the mesh electrode (220); the mesh electrode (220) is connected with the ground wire to form a discharge high-voltage loop;

the turbulent condensation section (3) comprises a shell and a vortex generating element (31) fixedly arranged in the shell.

Images