JP2008030028A - Multi-stage type cyclone apparatus and method for classifying and collecting particulate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-stage type cyclone apparatus and a method for classifying and collecting nanoparticles. <P>SOLUTION: The apparatus and the method are provided for classifying and collecting nanoparticles containing various sizes of particulates. A stream containing a plurality of different sizes of particulates passes through at least a first stage cyclone of the multi-stage type cyclone apparatus. The first stage cyclone collects a first particulate group. The stream passes through at least a second stage cyclone of the multi-stage type cyclone apparatus. The second stage cyclone collects a second particulate group. The barometric pressure width of the multi-stage type cyclone apparatus is 20 to 760 torr. The first stage cyclone has a cut-off aerodynamic diameter of d<SB>pa 50,1, j</SB>, and the second stage cyclone has a cut-off aerodynamic diameter of d<SB>pa 50,2, j</SB>. The first stage cyclone and the second stage cyclone are connected in series. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a multistage cyclone apparatus and a granular material classification and collection method.

  Nanotechnology is an important technology in the future high-tech industry, and is applied to industries such as chemistry, optics, electronics, ceramics, and biotechnology to strengthen the industrial layer and competitiveness and create high added value. It has become the mainstay of the high-tech industry. However, in the granular material production process, nano-level microscopic materials cannot be collected by a general granular material processing mechanism. Therefore, the inventor of the present plan in Taiwan on October 9, 1992 (2003) An invention proposal (Application No. 092128213) of “Method of collecting nanoparticles and method of designing cyclone” has been submitted to solve the problem of collecting particulate matter.

  However, it is impossible to classify and collect the granular materials according to the particle size effectively and to collect the granular materials directly using the cyclone, and it is very fine particles with high economic value. Items are mixed with fine and coarse particles and sold at low prices. Taking a known cyclone as an example, only granular materials of 10 μm or more can be collected, so how to effectively separate and collect each granular material, and how to improve the economic value of ultrafine granular materials by the classification method However, this is a problem that this plan solves.

  In order to remedy the above-mentioned drawbacks, the present invention aims to provide a multistage cyclone apparatus and a method for collecting and collecting particulate matter.

The multistage cyclone apparatus of the present invention comprises at least one first stage cyclone and at least one second stage cyclone, the first stage cyclone having a cut-off aerodynamic diameter d _{pa50,1, j} . The second stage cyclone has a cut-off aerodynamic diameter d _{pa50,2, j} . The first stage cyclone and the second stage cyclone are connected in series, and the cut-off aerodynamic diameter d _{pa50,1, j} is determined by the following equation:

1 and j above denote the jth cyclone in the first stage; μ is the gas viscosity; N is the number of blades; w is the thickness of the blade; P is the distance between the blades; n is the number of blade rotations; r _max and r _min are the outer diameter and inner diameter of the blade, respectively; Q is the gas volumetric flow rate; ζ is the fitting constant; C is the particulate matter slip correction factor.

The cut-off aerodynamic diameter d _{pa50,2, j} is determined by the following equation:

2 and j above represent the jth cyclone in the second stage; μ is the gas viscosity; N is the number of blades; w is the blade thickness; P is the distance between the blades; n is the number of blade rotations; r _max and r _min are the outer diameter and inner diameter of the blade, respectively; Q is the gas volumetric flow rate; ζ is the fitting constant; C is the particulate matter slip correction factor.

  In the particulate matter classification and collection method, an air flow including a plurality of particulates having different sizes passes through at least one first-stage cyclone of the multistage cyclone apparatus. The first granular material group is collected by the first stage cyclone. The airflow including a plurality of differently sized particles passing through the first stage cyclone passes through at least one second stage cyclone of the multistage cyclone device. The second group of particulates is collected by a second stage cyclone. The pressure in the first stage cyclone and the second stage cyclone is 20 to 760 Torr.

  The multistage cyclone apparatus and the granular material collection method of the present invention solve the problem that a large amount and a granular material in the known technology cannot be effectively classified and collected by the particle size, and have a high economic value of ultrafine particles. Prevents the product from being sold at a low price due to the mixing of fine and coarse particles, and effectively classifies the particles by particle size to achieve high economic value.

  1 and 8 are diagrams showing the particulate matter classification and collection method of the present invention. An air stream containing a plurality of different sized particles passes through at least one first stage cyclone 11. b. The first granular material group is collected by the first-stage cyclone 11. c. The airflow including a plurality of particles having different sizes passing through the first stage cyclone 11 passes through at least one second stage cyclone 12. d. The second granular group is collected by the second stage cyclone 12. The pressure range in the first stage cyclone 11 and the second stage cyclone 12 is 20 to 760 Torr. Referring to FIG. 1, it should be noted that the multistage cyclone apparatus 10 of the present invention operates under conditions of moderate vacuum (20 torr) to atmospheric pressure (760 torr), and the multistage cyclone apparatus 10 is A plurality of first stage cyclones 11 and a second stage cyclone 12 are provided, the first stage cyclones 11 are arranged in parallel with each other, the second stage cyclones 12 are also arranged in parallel with each other, and the first stage cyclone 11 and the second stage cyclone are arranged in parallel. Cyclone 12 corresponds and is connected in series. FIG. 1 shows a design of a classification mold factory for collecting granular materials. An air flow including a plurality of different-sized granular materials is first transmitted by a feeder 20 into a known cyclone 21, and then by a known cyclone 21. Collect the granular material of maximum particle size. The airflow further flows into the multistage cyclone device 10, and the gas flowing into the multistage cyclone device 10 passes through the plurality of first cyclones 11, and these first stage cyclones 11 have a large particle size in the airflow. Of particles (first level granule group) are collected, and then the airflow flows into the second stage cyclone 12, where the second stage cyclone 12 collects small particle size particles (second level granule group). Then, the large particle size granule (first level granule group) in the first stage cyclone 11 is sent to the first collector 22 and the small particle size granule in the second stage cyclone 12 ( The second level particulate group) is sent into the second collector 23. Finally, the airflow that has passed through the multistage cyclone 10 is subjected to final processing while passing through the filter 24 and the blower 25. It should be noted that the multi-stage cyclone 10 of the present invention is coupled to a bag-type dust collection facility (not shown) or other collection facility to help collect particulate matter. The multi-stage cyclone device 10 of the present invention can be combined with a bag-type dust collecting equipment, a bag-house type, a bag-filter, a HEPA filter, and Combines with an electrostatic precipitator to help collect particulate matter. In addition, before the airflow passes through the multistage cyclone apparatus 10, the airflow passes through a T-type three-way pipe (not shown), and the particulate matter having a particle size of 10 μm or more is filtered by the T-type three-way pipe. Can pass through the multi-stage cyclone device 10 and directly collect particulates of 10 μm or less.

  As shown in FIGS. 2 and 3, the first stage cyclone 11 and the second stage cyclone 12 of the present invention are all axial wing type cyclones, and are composed of a cabin 111 and a cyclone structure 112. An air flow inlet 113 for introducing an air flow, an air flow outlet 114, and an inner wall 115, the cabin structure 112 is located in the cabin 111, and the cyclone structure 112 is interposed between the air flow inlet 113 and the air flow outlet 114. The inner wall 115 of the cabin 111 forms a channel 116. The channel 116 generates rotation when the airflow passes through the channel 116, and the particulate matter in the airflow collides with the inner wall 115 in the cabin 111 due to centrifugal force. The cyclone structure 112 has a cylindrical blade 117 and an axial center of the cylindrical body 117, and has a spiral blade 118 installed on the cylindrical body 117, and the channel 116 is close to the spiral blade 118 and the blade 118. Defined by cabin 111. It should be noted that in this embodiment, the gas inlet 113 is installed at the upper part of the cabin 111, and the airflow outlet 114 is installed below the cyclone structure 112, and extends from the radial direction of the cabin 111.

  FIG. 4 shows another embodiment of the first stage cyclone 11 and the second stage cyclone 12. The structure is substantially the same, except that the gas inlet 113a of this embodiment is located above the cabin 111. The design direction of the gas inlet 113a and the cut line direction of the cabin 111 are similar, and the air flow outlet 114a is installed below the cyclone structure 112 and extends in the radial direction of the cabin 111.

  FIG. 5 is a diagram showing another embodiment of the first-stage cyclone 11 and the second-stage cyclone 12 of the present plan, and the structure is almost the same, but the difference is that the gas inlet 113b of the present embodiment has a cabin. The design direction of the gas inlet 113b and the cut line direction of the cabin 111 are the same, and the air flow outlet 114b is installed above the cyclone structure 112 and extends in the axial direction of the cabin 111.

  It should be noted that the structure of the cyclone of the present invention (first-stage cyclone 11 and second-stage cyclone 12) and the inventor of the present proposal “the method of collecting nanoparticles by the cyclone and the design of the cyclone” Unlike the cyclone structure of the "Method" invention (application number 092128213), the present invention further differs from the cyclone structure in the various cyclones, such as the designs of FIGS. 2, 4, and 5, and The design position of the air flow outlet is provided. In addition, the cyclone of this plan adopts a multistage design, so the atmospheric pressure applied in the cyclone is 20 to 760 Torr, which is clearly different from the applicable atmospheric pressure (20 Torr or less) submitted by the applicant of this plan. Because the applied air pressure is different, the theoretical equation for calculating the cut-off aerodynamic diameter also varies.

The first stage cyclone 11 and the second stage cyclone 12 of the present invention each have a cut-off aerodynamic diameter (d _pa50 ), and the cut-off aerodynamic diameter (d _pa50 ) is Is calculated by:

I and j above denote the jth cyclone in the i stage; μ is the gas viscosity; N is the number of blades; w is the thickness of the blade; P is the distance between the blades; n is the number of blade rotations; r _max and r _min are the outer diameter and inner diameter of the blade, respectively, Q is the gas volume flow rate, ζ is the fitting constant, C is the granular material slip correction coefficient, and the theoretical efficiency and experimental data in the literature agree with each other. slip correction factor C _i of the j-number of cyclones of the i _{stage, j} is calculated in the following formula (Hinds, WC, 1999, Aerosol Technology, 2 nd Ed., Wiley & Sons, Inc., 99.49.) :

dp is the particle size, λ _{i, j} is the free average path length of gas molecules in the j-th cyclone in the i-th stage, and its value and gas pressure are inversely proportional and directly proportional to the gas temperature.

は正規化パラメータ（normalized parameter）；Ψ_i,j,50＝８^*１０⁴（ｎｍ−ｌｐｍ）は粒状物の収集効率η_i,j＝０．５のときの正規化パラメータの値；ｄｐ_i,j第ｉ段階の第ｊ個のサイクロン中の粒状物粒径；Ｑ_i,j第ｉ段階の第ｊ個のサイクロンの気体流量；ζ’は適合常数；であり、理論効率と文献上実験データは符合する。 In the process of producing a gas containing particulate matter according to the present invention, an apparatus and a method for classifying and collecting particulate matter are designed and tested under conditions of moderate hollow (20 torr) to normal pressure (760 torr). A laboratory experiment is performed, and the collection efficiency of the i-th jth cyclone granulate is calculated by the following formula:

Is the normalized parameter; Ψ _{i, j, 50} = 8 ^* 10 ⁴ (nm−lpm) is the value of the normalized parameter when the particulate collection efficiency η _{i, j} = 0.5; dp _{i , j} Particle size _{in j-} th cyclone in i-stage; Q _{i, j} gas flow rate in j-th cyclone in i-stage; ζ ′ is a compatible constant; experimental efficiency and literature The data matches.

に対する粒状物収集効率テスト結果は、図から分かるように、正規化パラメータがΨ_i,j,50＝８^*１０⁴ｓ（ｎｍ−ｌｐｍ）のとき、粒状物の収集効率はη_i,j＝０．５（すなわち、５０％）で、適当な流量と圧力下で操作するとき、粒径の大きさは１００（ｎｍ）に達する。 Referring to FIG. 6, the normalization parameters of the axial cyclone of the present invention:

As can be seen from the figure, when the normalization parameter is Ψ _{i, j, 50} = 8 ^* 10 ⁴ s (nm−lpm), the collection efficiency of the granular material is η _{i, j} = At 0.5 (ie 50%), the particle size reaches 100 (nm) when operating under appropriate flow rate and pressure.

As can be seen from the above, there is a fixed relationship between η _{i, j} and the particle size dp of the granular material. When the granular material is dense (non-porous), the particle size dp is determined by the BET specific surface area analysis method. The relationship between the specific surface area S and the particle size dp of the spherical granular material is represented by the following formula:

ρ _p is the density of the granular material, and FIG. 7 is a graph showing the relationship between the particle diameter dp and the specific surface area S of the granular material generated by taking the density ρ _p = 5.8 g / cm ³ of the granular material as an example. For example, when the specific surface area S is 10.3 m ² / g, the particle size at this time is 0.1 μm (that is, 100 nm), and it should be noted that the present embodiment analyzes using the BET specific surface area. When using a filter (not shown), the ratio of air body cloth to the filter cloth used for the filter (m ³ / min / m ² ; proportional to the amount of waste air per unit time flowing into the unit filter cloth area) is about 1 If the particulate collection efficiency η _{i, j} needs to be improved at 0.95, the air body cloth ratio is reduced to 1 or 1 or less.

When the granular material has another shape (not a spherical shape), the relationship between the specific surface area S and the particle size dp is corrected by adding the shape correction factor ζ, and is expressed as follows:

  The multistage cyclone apparatus and the granular material collection method of the present invention solve the problem that a large amount and a granular material in the known technology cannot be effectively classified and collected by the particle size, and have a high economic value of ultrafine particles. Prevents products from being sold at a low price due to the inclusion of fine or coarse particles. The multistage cyclone apparatus and the granular material collection method of the present invention effectively classify granular materials according to particle size and achieve high economic value.

  In the present invention, preferred embodiments have been disclosed as described above. However, the present invention is not limited to the present invention, and any person who is familiar with the technology can use various methods within the spirit and scope of the present invention. Variations and moist colors can be added, so the protection scope of the present invention is based on what is specified in the claims.

It is a design drawing of the classification mold factory of the granular material collection of the present invention. It is a figure which shows the cyclone of this invention. It is a cyclone structure figure of the present invention. It is a figure which shows another Example of the cyclone of this invention. It is a figure which shows another Example of the cyclone of this invention. FIG. 3 is a relationship diagram between collected particulate matter normalization parameters and collection efficiency of the multistage cyclone device of the present invention. When the density of the granular material is ρ _p = 5.8 g / cm ³ , it is a relationship diagram between the particle diameter dp of the granular material and the specific surface area S. FIG. It is process drawing of the granular material classification | category collection method of this invention.

Explanation of symbols

10 Multistage cyclone apparatus 11 First stage cyclone 111 Cabin 112 Cyclone structure 113, 113a, 113b Airflow inlet 114, 114a, 114b Airflow outlet 115 Inner wall 116 Channel 117 Cylindrical body 118 Spiral blade 12 Second stage cyclone 20 Feeder 21 Known Cyclone 22 first collector 23 second collector 24 filter 25 blower d _pa50 cut-off aerodynamic diameter

Claims (11)

A method for collecting and collecting particulate matter, the process comprising:
An air stream comprising a plurality of different sized particulates passes through at least one first stage cyclone;
Collecting the first granular material group by the first stage cyclone;
An air flow including a plurality of particles having different sizes that have passed through the first stage cyclone passes through at least one second stage cyclone;
Collecting the second granular group by the second stage cyclone,
The method according to claim 1, wherein a pressure width in the first stage cyclone and the second stage cyclone is 20 to 760 Torr. When the number of the first stage cyclones is plural, the first stage cyclones are installed in parallel with each other, and when the number of the second stage cyclones is plural, the second stage cyclones are installed in parallel with each other. The method according to claim 1. The method of claim 1, wherein the first stage cyclone and the second stage cyclone are connected in series. The first stage cyclone and the second stage cyclone are axial wing type cyclones, and the axial wing type cyclones have a cabin and a cyclone structure, and the cabin has an air flow inlet for introducing the air flow, an air flow outlet, And the inner wall of the cyclone structure is located between the airflow inlet and the airflow outlet, the inner wall of the cyclone structure forms a channel, and the airflow passes through the channel. The method according to claim 1, wherein a rotation is generated when the particulate matter in the airflow collides with an inner wall of the cabin by a centrifugal force. The cyclone structure includes a cylindrical body and a spiral blade installed on the cylindrical body, and the channel is defined by a spiral blade and a cabin adjacent to the blade. 5. The method of claim 4, wherein: The first stage cyclone and the second stage cyclone each have a cut-off aerodynamic diameter (d _pa50 ), and the cut-off aerodynamic diameter (d _pa50 ) is calculated by the following equation: ,

Above i and j the j-number of cyclones in the i-th stage, mu is the gas viscosity, N is the number of blades, w is the blade thickness, P is the blade distance, n represents flipping number of blades; r _max, and , R _min are the outer diameter and inner diameter of the blade, Q is the gas volume flow rate, ζ is the adaptive constant, and C is the particulate slip correction factor. The slip correction coefficient C _{i, j} of _{the j-th} cyclone in the i-th stage is calculated by the following formula:

The method according to claim 6, wherein dp is a particle size, and λ _{i, j} is a free average path length of gas molecules in the j-th cyclone in the i-th stage. A multistage cyclone device,
At least one first stage cyclone having at least one blade and a cut-off aerodynamic diameter d _{pa50,1, j} provided with said blade;
At least one second stage cyclone having at least one blade and a cut-off aerodynamic diameter d _{pa50,2, j} provided with said blade;
The first stage cyclone and the second stage cyclone are connected in series, and the cut-off aerodynamic diameter d _{pa50,1, j} is obtained by the following equation:

1 and j are the j-th cyclones in the first stage, μ is the gas viscosity, N is the number of blades, w is the thickness of the blade, P is the distance between the blades, n is the number of blade rotations, r _max , and , R _min are the outer diameter and inner diameter of the blade, Q is the gas volume flow rate, ζ is the adaptation constant, C is the granular material slip correction coefficient,
The cut-off aerodynamic diameter d _{pa50,2, j} is determined by the following equation:

2 and j above are the jth cyclone in the second stage, μ is the gas viscosity, N is the number of blades, w is the thickness of the blade, P is the distance between the blades, n is the number of blade rotations, r _max , and , R _min are the outer diameter and inner diameter of the blade, Q is the gas volume flow rate, ζ is a compatible constant, and C is a granular material slip correction coefficient. When the number of the first stage cyclones is plural, the first stage cyclones are installed in parallel with each other, and when the number of the second stage cyclones is plural, the second stage cyclones are installed in parallel with each other. The multistage cyclone device according to claim 8. The first stage cyclone and the second stage cyclone are axial wing type cyclones, and the axial wing type cyclones have a cabin and a cyclone structure, and the cabin has an air flow inlet for introducing the air flow, an air flow outlet, And the inner wall of the cyclone structure is located between the airflow inlet and the airflow outlet, the inner wall of the cyclone structure forms a channel, and the airflow passes through the channel. 9. The multistage cyclone apparatus according to claim 8, wherein a rotation is generated and the particulate matter in the airflow collides with an inner wall of the cabin by a centrifugal force. The cyclone structure includes a cylindrical body and a spiral blade installed on the cylindrical body, and the channel is defined by a spiral blade and a cabin adjacent to the blade. The multistage cyclone device according to claim 8.

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