CN205786028U - A kind of PM2.5 screening plant based on particle diameter - Google Patents

Abstract

The utility model discloses a particle size-based PM2.5 screening device, which screens fine particles according to the size of the fine particles, and includes a closed container and more than two trays, the trays are placed inside the closed container, and the trays have different A uniformly distributed array of pits with a diameter size, the pits are blind holes; there are through holes coaxial with the pits in the pits; the pits and the through holes form a two-layer structure, and the diameters of the pits and through holes are selected according to The particle size of the fine particles is determined, the blind hole is used to collect the fine particles of the corresponding particle size, and the through hole is used to discharge the fine particles smaller than the corresponding particle size. The utility model has high collection precision, controllable collection quantity, and the fine particles will not stick and agglomerate, so that extraction and detection are convenient.

Description

A PM2.5 screening device based on particle size

technical field

The utility model relates to the field of chemical analysis, in particular to a particle size-based PM2.5 screening device.

Background technique

PM2.5 is fine particulate matter, which refers to particulate matter with an aerodynamic diameter less than or equal to 2.5 μm in the atmospheric environment. Although PM2.5 is a very small part of the earth's atmospheric air, it has a great impact on the environment and human health. Inhalable particles of different particle sizes staying in different parts of the respiratory tract will cause different respiratory diseases, and PM2.5 Seriously affect air quality and visibility. Therefore, the separation of PM2.5 based on particle size can be used to specifically analyze the impact of PM2.5 on human health and the environment.

At present, the main methods for separating particulate matter in the air based on particle size are: (1) filter membrane weighing method, which is to extract a certain volume of air at a constant rate through a sampler, and the particulate matter in the air is trapped on the filter membrane. The weight change before and after sampling and the sampled air volume are used to calculate the concentration; however, some extremely fine particles can still pass through the filter membrane, resulting in a low result, and other substances may also be absorbed by the filter membrane, resulting in a high result. (2) Light scattering method, because the relationship between light scattering and particle concentration is affected by the chemical composition, shape, specific gravity and other factors of the particle in the actual process, the accuracy of this technology is not high. (3) The β-ray method, whose basic principle is to measure the change in the amount of atmospheric particulate matter by using the change in the attenuation of the β-ray released by the particulate matter accumulated on the adaptive filter membrane to carbon-14, but the measurement data generally has deviations, and in humid High temperature areas have a high failure rate. (4) Micro oscillating balance method mainly uses the principle of micro oscillating balance with conical elements, but the current technology cannot solve the loss of volatile and semi-volatile substances after the sample is heated, resulting in low measurement results. Moreover, the above-mentioned methods are particle separation methods at the particle size range level, and the separation results are relatively rough, and PM2.5 cannot be accurately separated according to its particle size, which will affect the detection and subsequent analysis of PM2.5.

Contents of the invention

The purpose of the utility model is to overcome the shortcomings in the prior art, and provide a PM2.5 screening device based on particle size, which can accurately separate PM2.5, and has simple process and convenient operation.

The purpose of this utility model is achieved through the following technical solutions:

A PM2.5 screening device based on particle size, which screens fine particles according to their size, includes a closed container 1 and more than two trays, and the trays are placed inside the closed container 1 .

A PM2.5 screening method based on particle size is to screen the fine particles according to the size of the fine particles, including the following steps:

(1) Pass a certain amount of dried air to be tested into the airtight container 1, and place two or more pallets in the airtight container 1;

(2) Then seal the airtight container 1 and let it stand for 10 to 30 minutes, so that the fine particles 5 in the air to be tested are fully deposited into the array pits 6 of corresponding sizes on each tray;

(3) All the trays are taken out from the airtight container 1, and the fine particles 5 with corresponding particle sizes are extracted from the arrayed pits 6 of different sizes, and then detected and analyzed.

The size of the tray is: length and width 1-500mm, thickness 1-5mm, and the shape is not limited, it can be square or round; the preferred size is 100*100*1mm.

The tray has uniformly distributed array pits with different diameters and sizes, and the pits are blind holes; there are through holes coaxial with the pits in the pits; the pits and the through holes form a two-layer structure, and the pits and the through holes The diameter of the hole is determined according to the particle size of the screened fine particles. The blind hole is used to collect the fine particles of the corresponding particle size, and the through hole is used to discharge the fine particles smaller than the corresponding particle size; the more the number of pits, the more fine particles are collected. more.

The number of pits in the tray is 10000-108, the distance between the pits is ^0.1-0.5um , and the pits are in a rectangular array and centered on the tray. Moreover, the shape, size, pit pitch, quantity and array of the tray can be changed and optimized according to specific needs.

The material of the tray is a material with a smooth surface and easy microfabrication such as metal, polymer or glass.

The pits and through-holes on the tray are processed by micro-manufacturing technology, and the shape accuracy is controllable; the bottom of the pits can be processed into a hemispherical shape, which facilitates the discharge of fine particles smaller than or equal to the diameter of the through-hole and prevents them from remaining in the In the pit.

There are 3 trays, including tray one 2, tray two 3, and tray three 4.

The pit 6 of the tray 1 2 has a diameter of 0.5um and a depth of 0.5um, and is used to collect fine particles 5 with a diameter less than or equal to 0.5um.

The pit 6 of tray 2 3 has a diameter of 1.5um and a depth of 1.5um, and a through hole 7 with a diameter of 0.5um coaxial with the pit is opened in the pit for collecting particles with a diameter between 0.5-1.5um The fine particles 5 whose particle size is less than or equal to 0.5um will be discharged through the through hole 7 of the tray two 3 and will not remain in the pit 6 thereof.

The pit 6 of tray three 4 has a diameter of 2.5um and a depth of 2.5um, and a through hole 7 with a diameter of 1.5um coaxial with the pit is opened in the pit for collecting particles with a diameter between 1.5-2.5um The fine particles 5 whose particle size is less than or equal to 1.5um will be discharged through the through hole 7 of the tray three 4 and will not remain in the pit 6 thereof.

The collection of fine particles with different particle sizes can also be realized by preparing array pits with different diameters.

In step 3, the particle size of the fine particles 5 collected by tray one 2 is less than or equal to 0.5um; the particle size of the fine particles 5 collected by tray two 3 is between 0.5-1.5um; the particle size of the fine particles 5 collected by tray three 4 is Between 1.5-2.5um.

The principle of this device is the principle of filtration. In theory, the fine particles are regarded as a sphere, and the diameter and depth of a single pit determine the size and number of collected fine particles; among them, the pits on the tray 1 and 2 are used to collect particles with a diameter less than or equal to 0.5 For fine particles of um, one pit holds one fine particle; the pit of tray 2 3 is used to collect fine particles with a particle size between 0.5-1.5um, and the fine particles with a particle size of 0.5um or less will be discharged through the through hole ;The pits of tray 3 and 4 are used to collect fine particles with a particle size of 1.5-2.5um, and the fine particles with a particle size of 1.5um or less will be discharged through the through holes; the diameter and depth of a single pit determine the fine particles contained The size and quantity of particles. In theory, a single pit can accommodate a single fine particle of the corresponding particle size. The more the number of array pits, the more fine particles will be collected; and the air to be tested will be passed in after drying to prevent fine particles from sticking Accompanying and agglomerating; fine particles are accommodated in pits after standing, which is convenient for extraction and detection.

Compared with the prior art, the utility model has the following advantages and effects:

(1) The utility model collects fine particles based on particle size, and the collection precision is high, and the collection quantity is controllable.

(2) The utility model carries out drying treatment on the air to be tested, so that the fine particles will not adhere and agglomerate, and the extraction and detection are convenient.

(3) The utility model is realized by adopting micro-manufacturing technology to prepare uniformly distributed array pits with different sizes on the tray, and the diameter and depth of the pits are controllable.

Description of drawings

Fig. 1 is a structural schematic diagram of an airtight container and a tray.

Figure 2 is a schematic diagram of the deposition process of fine particles.

Figure 3 is a schematic diagram of the deposition of fine particles on the tray.

In the figure, 1: airtight container; 2, tray one; 3, tray two; 4, tray three; 5, fine particles; 6, pit; 7, through hole.

detailed description

The utility model will be further described in detail below in conjunction with the examples, but the implementation of the utility model is not limited thereto.

Example

A PM2.5 screening device based on particle size, which screens fine particles according to the size of the fine particles, including an airtight container 1 and tray one 2, tray two 3, and tray three 4, and the three trays are placed in the airtight container internal.

A PM2.5 screening method based on particle size is to screen the fine particles according to the size of the fine particles, including the following steps:

(1) A certain amount of dried air to be tested is passed into the airtight container 1, and three trays are laid flat in the airtight container 1: including tray one 2, tray two 3, and tray three 4, as shown in Figure 1;

(2) Then seal the airtight container 1 and let it stand for 10 to 30 minutes, so that the fine particles 5 in the air to be tested are fully deposited in the array pits 6 of corresponding sizes on each tray, as shown in Figure 2;

(3) Take out all trays from the airtight container 1, extract the fine particles 5 of corresponding particle diameters from the array pits 6 of different sizes respectively, and carry out detection and analysis, as shown in Figure 3, wherein, tray one 2 collects The particle size of fine particles 5 is less than or equal to 0.5um; the particle size of fine particles 5 collected by tray two 3 is between 0.5-1.5um; the particle size of fine particles 5 collected by tray three 4 is between 1.5-2.5um.

The pit 6 of the tray 1 2 has a diameter of 0.5um and a depth of 0.5um, and is used to collect fine particles 5 with a diameter less than or equal to 0.5um.

The pit 6 of tray 2 3 has a diameter of 1.5um and a depth of 1.5um, and a through hole 7 with a diameter of 0.5um coaxial with the pit is opened in the pit for collecting particles with a diameter between 0.5-1.5um. Among them, the fine particles 5 with a particle size less than or equal to 0.5um will be discharged through the through holes 7 of the tray two 3 and will not remain in the pit 6.

The pit 6 of tray three 4 has a diameter of 2.5um and a depth of 2.5um, and a through hole 7 with a diameter of 1.5um coaxial with the pit is opened in the pit for collecting particles with a diameter between 1.5-2.5um. Among them, the fine particles 5 whose particle size is less than or equal to 1.5um will be discharged through the through hole 7 of the tray three 4, and will not remain in the pit 6.

Claims (8)

1. A PM2.5 screening device based on particle size, characterized in that: it includes an airtight container and more than two trays, and the tray is placed inside the airtight container; the size of the tray is: length and width 1 ~ 500mm, thickness 1 ~5mm; the tray has uniformly distributed array pits of different diameters, and the pits are blind holes; there are through holes coaxial with the pits in the pits; the pits and the through holes form a two-layer structure, and the pits The diameters of the pits and through holes are determined according to the particle size of the screened fine particles, the blind holes are used to collect fine particles of the corresponding particle size, and the through holes are used to discharge the fine particles smaller than the corresponding particle size. 2. The PM2.5 screening device based on particle size according to claim 1, characterized in that: the number of pits in the tray is 10,000 to ¹⁰⁸ , and the distance between the pits is 0.1 to 0.5um. Centered on the tray in a rectangular array. 3. The PM2.5 screening device based on particle size according to claim 1, characterized in that: the material of the tray is metal, polymer or glass. 4. The PM2.5 screening device based on particle size according to claim 1, characterized in that: the bottom of the pit is hemispherical. 5. The PM2.5 screening device based on particle size according to claim 1, characterized in that: there are three trays, including tray one (2), tray two (3), and tray three (4). 6. The PM2.5 screening device based on particle size according to claim 5, characterized in that: the pit diameter of tray one (2) is 0.5um, the depth is 0.5um, and is used to collect particle diameters less than or equal to 0.5um of fine particles. 7. PM2.5 screening device based on particle size according to claim 5, is characterized in that: the diameter of the pit of tray two (3) is 1.5um, and depth is 1.5um, has the same diameter as the pit in the pit. A through hole with a diameter of 0.5um in the center of the shaft is used to collect fine particles with a diameter between 0.5-1.5um. 8. PM2.5 screening device based on particle size according to claim 5, is characterized in that: the pit diameter of tray three (4) is 2.5um, and depth is 2.5um, has the same diameter as pit in the pit. The shaft center has a through hole with a diameter of 1.5um, which is used to collect fine particles with a diameter between 1.5-2.5um.