Compact two-stage electrostatic aerosol particle removal device for high wind speeds

Abstract

The present invention discloses a compact two-stage electrostatic aerosol particle removal device for use at high wind speeds. The present invention includes a precharge stage device, a collection stage device, and a shell device. The present invention improves the precharge stage device by adding a grounding electrode while limiting the overall length to 400 mm, thereby increasing the minimum value of the space charge density, improving the distribution of the space charge, increasing the particle charge, and enhancing the dust removal efficiency of the two-stage electrostatic at a wind speed of 5 m / s. In summary, the present invention ensures that the two-stage electrostatic precipitator has a small volume while improving its dust removal efficiency at a wind speed of 5 m / s.

Description

Technical Field

[0001] The invention relates to the technical field of collecting and removing micron and submicron particles, and in particular to a compact two-stage electrostatic aerosol particle removal device applied to high wind speeds. Background Art

[0002] With the rapid development of China's economy and the improvement of residents' living standards, cooking fumes have become another source of air pollution. According to data from relevant Chinese departments, urban fumes contribute 5% of PM2.5 sources; and in recent years, the Ministry of Environment has launched the revision of relevant standards for restaurant fumes emissions, and will tighten the control standards for fumes emissions.

[0003] According to relevant research, the particle size distribution of oil fume particles is wide, but 30% are 0.5-5μm particles. Submicron particles can cause damage to the lungs through the respiratory tract and need to be collected by technical means.

[0004] Electrostatic precipitators are widely used, but there are two problems when applied to home environments: one is that they are too large, usually more than 1m in length, and cannot be used in the small environment of a home kitchen; the other is that in existing research on electrostatic precipitators, the wind speed is set below 2m / s. However, based on the position of the fan duct, the wind speed of the range hoods on the market is calculated to be 3-5m / s. In addition, the electrodes of conventional two-stage electrostatic precipitators are composed of only a simple single discharge electrode and a single grounding plate, which produces a small space charge density, resulting in a small amount of particle charge, which in turn causes the electric field force to be insufficient to deflect the particles to the collection-level grounding electrode and escape from the electrostatic precipitator, so its dust removal efficiency is poor at high wind speeds. If the electrostatic precipitator designed by existing research is used, it will be difficult to use in a home environment. In addition, as a two-stage electrostatic device for purifying oil fume particles, excessively high working voltage will bring safety hazards, limiting the method of improving the dust removal efficiency of the electrostatic precipitator. Summary of the invention

[0005] The purpose of the present invention is to solve the deficiencies of the prior art and to provide a compact two-stage electrostatic aerosol particle removal device for use under high wind speeds.

[0006] The technical solution of the present invention is:

[0007] One aspect of the present invention provides a compact two-stage electrostatic aerosol particle removal device for use under high wind speeds, comprising a pre-charge stage device, a collection stage device and a housing device.

[0008] A pre-charge level device generates negative ions to charge the particles;

[0009] a collecting stage device for collecting particles deflected to a ground electrode by the electric field force;

[0010] Enclosure device, providing insulation protection;

[0011] The precharge level device comprises a discharge electrode and a grounding electrode; the grounding electrode is arranged around the discharge electrode; the minimum value of the generated space charge density is reduced, and the distribution shape of the space charge is improved from an ellipse to a circle, thereby increasing the charge amount of the particles.

[0012] Furthermore, the collection stage device comprises a deflection electrode and a grounding electrode; the deflection electrode and the dust collecting plate are kept parallel and arranged alternately.

[0013] Furthermore, the shell device is made of insulating material, and integrally wraps the pre-charge stage device and the collection stage device, retaining the air inlet and the air outlet.

[0014] Furthermore, the discharge electrode in the precharge level device has a diameter of 0.2 mm, an operating voltage of -10 kV, and four grounding electrodes arranged in a rectangular shape with the discharge electrode as the center.

[0015] Furthermore, the operating voltage of the deflection electrodes in the collection stage device is -10kV.

[0016] Another aspect of the present invention provides application of the device in the wind speed of a fan duct of a range hood.

[0017] The beneficial effects of the present invention are:

[0018] 1. The overall length of the present invention is 400 mm, and the distance between the pre-charge stage device and the collection stage device is 20 mm to ensure that the mutual interference of the electric potential between the two stages is minimized, which not only ensures that the present invention has the advantage of small size, but also maximizes the dust removal efficiency of the present invention.

[0019] 2. The working voltage of the discharge electrode of the precharge level device in the present invention is -10kv, which reduces the risk of fire caused by accidents while ensuring the normal operation of the present invention.

[0020] 3. The working wind speed of the present invention can reach 5m / s, which can adapt to the wind speed of the fan duct of the range hood on the market.

[0021] 4. The present invention reduces the minimum value of the generated space charge density by increasing the number of grounding electrodes arranged around the discharge electrode, and improves the distribution shape of the space charge from an elliptical shape to a circular shape, thereby increasing the charge of the particles, allowing the particles to obtain a greater electric field force in the collection stage device and reach the grounding electrode of the collection stage device more quickly, thereby enhancing the dust removal efficiency of the present invention.

[0022] 5. The pre-charge level device and the collection level device in the present invention adopt a structured minimum design and can be expanded horizontally by stacking, thereby enhancing the ability of the present invention to adapt to different installation environment widths. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The figure is a schematic diagram of the appearance and structure of a compact two-stage electrostatic aerosol particle removal device used under high wind speed;

[0024] Figure 2 A schematic diagram of the internal structure of a compact two-stage electrostatic aerosol particle removal device for use at high wind speeds;

[0025] Figure 3 A comparison diagram of the minimum value of space charge density between the present invention and a common two-stage electrostatic precipitator without improvement in the pre-charge stage;

[0026] Figure 4 The figure is a comparison chart of the dust removal efficiency of the two-stage electrostatic precipitator of the present invention and that of the two-stage electrostatic precipitator without improvement in the pre-charge stage. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with the accompanying drawings and implementation modes.

[0028] like Figure 1 and Figure 2 As shown, the present invention includes an insulating shell 1, a first grounding electrode 2, a first discharge electrode 3, a second grounding electrode 4, a third grounding electrode 5, a fourth grounding electrode 6, a second discharge electrode 7, a fifth grounding electrode 8, a sixth grounding electrode 9, a seventh grounding electrode 10, an eighth grounding electrode 11, a first deflection electrode 12, a ninth grounding electrode 13, a second deflection electrode 14, a tenth grounding electrode 15, an eleventh grounding electrode 16, and a twelfth grounding electrode 17.

[0029] The precharge level device includes a first grounding electrode 2, a first discharge electrode 3, a second grounding electrode 4, a third grounding electrode 5, a fourth grounding electrode 6, a second discharge electrode 7, a fifth grounding electrode 8, a sixth grounding electrode 9, a seventh grounding electrode 10, an eighth grounding electrode 11, a tenth grounding electrode 15, an eleventh grounding electrode 16, and a twelfth grounding electrode 17.

[0030] The collection stage device includes a sixth grounding electrode 9 , a first deflection electrode 12 , a ninth grounding electrode 13 , a second deflection electrode 14 , and a twelfth grounding electrode 17 .

[0031] The sixth grounding electrode 9 and the twelfth grounding electrode 17 are common grounding electrodes for the pre-charge stage device and the collection stage device.

[0032] Furthermore, the diameter of the first discharge electrode 3 and the second discharge electrode 7 is 0.2 mm, and the spacing between the third grounding electrode 5, the sixth grounding electrode 9 and the twelfth grounding electrode 17 is 20 mm. The working voltage of the first discharge electrode 3 and the second discharge electrode 7 is fixed at -10 kV, while ensuring the normal corona discharge and ensuring safety.

[0033] Furthermore, the first discharge electrode 3 and the second discharge electrode 7 need to be arranged on the mid-perpendicular line of the third grounding electrode 5 to ensure the utilization of the grounding electrode by corona discharge.

[0034] Furthermore, the length of the third grounding electrode 5 is 60 mm, which needs to be 3 times the distance from the first discharge electrode 3 and the second discharge electrode 7 to the third grounding electrode 5 to ensure the best corona discharge configuration.

[0035] Furthermore, the diameters of the first grounding electrode 2, the second grounding electrode 4, the tenth grounding electrode 15, and the eleventh grounding electrode 16 are all 1 mm, and the distance between them and the first discharge electrode 3 is 25 mm. The distance between the first grounding electrode 2, the eleventh grounding electrode 16 and the twelfth grounding electrode 17 is 13 mm; the distance between the second grounding electrode 4, the tenth grounding electrode 15 and the third grounding electrode 5 is 13 mm. This arrangement distance can ensure the minimum impact on the flow field, while maximizing the improvement of the distribution of space charges.

[0036] Furthermore, the fourth grounding electrode 6, the fifth grounding electrode 8, the seventh grounding electrode 10, and the eighth grounding electrode 11 are all 1 mm in diameter, and are 25 mm apart from the second discharge electrode 7; the fourth grounding electrode 6, the eighth grounding electrode 11 are 13 mm apart from the third grounding electrode 5; the seventh grounding electrode 10, the eighth grounding electrode 11 are 13 mm apart from the sixth grounding electrode 9. This arrangement distance can ensure the minimum impact on the flow field, while maximizing the improvement of the distribution of space charges.

[0037] Furthermore, the working voltage of the first deflection electrode 12 and the second deflection electrode 14 is -10 kV to ensure uniform distribution of the electric field.

[0038] Furthermore, the sixth grounding electrode 9, the first deflection electrode 12, the ninth grounding electrode 13, and the second deflection electrode 14 have the same spacing to maintain a stable electric field.

[0039] Furthermore, all components are connected to the insulating housing 1, and the connection methods used include but are not limited to adhesion, screw connection, bolt connection, etc.

[0040] Furthermore, holes may be opened in the insulating housing 1 to facilitate the connection of power and ground wires.

[0041] The specific working process of the device is as follows:

[0042] The corona inception voltage of corona discharge (Pick's law) is:

[0043]

[0044] Wherein, δ is the environmental coefficient compared with that at normal temperature and pressure, r is the radius of the discharge electrode, and d is the distance from the discharge electrode to the ground electrode.

[0045] According to Pick's law, since the working voltage of the first discharge electrode 3 and the second discharge electrode 7 is greater than the corona inception voltage, a corona discharge phenomenon will occur. Corona discharge will generate a large number of negative ions around the discharge electrode, and move toward the ground electrode under the action of the electric field, thus forming a space charge field. After the airflow carrying particles enters the precharge level device, the negative ions will combine with the particles to form charged particles. Due to the increase in the number of ground electrodes, the space charge distribution changes from elliptical to circular, and the distribution range is wider. At the same time, the minimum value of the space charge density decreases, indicating that the number of negative ions in the space increases. Therefore, the charge of the particles will increase when passing through the precharge level device.

[0046] After the charged particles enter the collection stage device with the airflow, they will be affected by the electric field force. Since the direction of the electric field force is perpendicular to the flow direction of the airflow, the particles will move toward the sixth grounding electrode 9, the ninth grounding electrode 13, and the twelfth grounding electrode 17 and deposit on the electrodes. As the charge of the particles increases, the electric field force they are subjected to will also increase, and they can reach the grounding electrode in a shorter time, thereby better completing the particle removal work.

[0047] like Figure 3 As shown, under the test conditions of normal temperature and pressure, the minimum space charge density generated by the pre-charge level device in the present invention is 1.2 times that of the two-stage electrostatic precipitator without improved pre-charge level. A lower space charge density value indicates that more negative ions are generated. The more negative ions there are in the space, the higher the probability of particles colliding with them, and the more charged they are.

[0048] like Figure 4 As shown, the test conditions are normal temperature and pressure, and at a wind speed of 5m / s, the dust removal efficiency of the present invention is higher than that of the two-stage electrostatic precipitator without improvement in the pre-charge stage. Except for 0.8 micron particles, the particles of other particle sizes are improved. Among them, the dust removal efficiency of 2 micron particles is improved by 1.35%, and the dust removal efficiency of 4 micron particles is improved by 16.35%.

Claims

1. A compact two-stage electrostatic aerosol particle removal device for high wind speed, with a working wind speed of 5m / s, including a pre-charge stage device, a collection stage device and a housing device, characterized by: A pre-charge level device generates negative ions to charge the particles; a collecting stage device for collecting particles deflected to a ground electrode by the electric field force; Enclosure device, providing insulation protection; The pre-charge level device comprises a discharge electrode and a ground electrode; the ground electrode is arranged around the discharge electrode; the minimum value of the generated space charge density is reduced, and the distribution shape of the space charge is improved from an ellipse to a circle, thereby increasing the charge amount of the particles; The collecting stage device comprises a deflection electrode and a grounding electrode; the deflection electrode and the dust collecting plate are kept parallel and arranged alternately; The discharge electrode in the precharge level device has a diameter of 0.2mm, an operating voltage of -10kv, uses corona discharge, and has four grounding electrodes arranged in a rectangular shape with the discharge electrode as the center; The operating voltage of the deflection electrodes in the collection stage device is -10kV.

2. The compact two-stage electrostatic aerosol particle removal device for use at high wind speeds according to claim 1 is characterized in that: The shell device is made of insulating material, and integrally wraps the pre-charge stage device and the collection stage device, retaining the air inlet and the air outlet.

3. Application of the device according to claim 1 or 2 in the wind speed of a fan duct of a range hood.

Images