TW202024595A - Suspended particle impact plate and suspended particle size-selective sampler including a substrate, a porous metal sheet, a glass fiber filter paper, a first silicon oil layer and a second silicon oil layer - Google Patents

Abstract

A suspended particle impact plate includes a substrate, a porous metal sheet, a glass fiber filter paper, a first silicon oil layer and a second silicon oil layer. The porous metal sheet is arranged on the substrate and provided with a plurality of holes. The glass fiber filter paper is arranged on the porous metal sheet. The first silicon oil layer is formed on the glass fiber filter paper. The second silicon oil layer is impregnated in the glass fiber filter paper and the holes of the porous metal sheet. The present invention also provides a suspended particle size-selective sampler, which includes an outer shell, a deflector, the suspended particle impact plate and a size-selective inlet. The outlet end of the deflector is arranged between the size-selective inlet and the suspended particle impact plate. The suspended particle impact plate can provide sampling stability for a long period to the suspended particle size-selective sampler.

Description

Suspended particle impact plate and suspended particle diameter sampler

The present invention relates to a suspended particle impact plate, in particular to a PM ₁₀ impact plate and a PM ₁₀ split-diameter sampler containing the suspended particle impact plate.

The existing suspended particle sampler is suitable for collecting air containing suspended particles in the surrounding environment, and the impact plate is used to separate and collect suspended particles with different inertial masses (or aerodynamic particle diameters). However, due to the turbulent flow of the airflow inside the suspended particle sampler, the collection efficiency is not ideal. Generally, lubricant is applied to the surface of the impact plate to improve the collection efficiency of suspended particles.

However, the cumulative load of particles on the surface of the impact plate will continue to increase with the collection time, so that the suspended particles in the gas entering the sub-diameter sampler no longer impact on the impact plate, but on the particles accumulated there. This results in a significant drop in the collection efficiency of suspended particles, errors in sampling concentration, and deviation of particle size distribution from small particle size intervals. Therefore, after continuous collection for a period of time, it is often necessary to clean and flush the particles accumulated on the impact plate and recoat. Cover with lubricant.

Therefore, the purpose of the present invention is to provide a suspended particle impact plate that can overcome the above-mentioned disadvantages of the prior art.

Therefore, the suspended particle impact plate of the present invention includes a substrate, a porous metal sheet, a glass fiber filter paper, a first silicone oil layer and a second silicone oil layer. The porous metal sheet is arranged on the substrate and has a plurality of holes. The glass fiber filter paper is arranged on the porous metal sheet. The first silicone oil layer is formed on the glass fiber filter paper. The second silicone oil layer is impregnated in the holes of the glass fiber filter paper and the porous metal sheet.

Therefore, another object of the present invention is to provide a suspended particle sampler that can overcome the above-mentioned disadvantages of the prior art.

Therefore, the aerosol sub-diameter sampler of the present invention includes a casing, a diversion tube, a suspended particle impact plate as described above, and a sub-diameter inlet. The shell defines a dividing chamber located inside and includes a sampling port communicating with the outside. The guide tube is arranged in the shell, and includes an inlet end connected to the sampling port and an outlet end in the dividing chamber. The first silicon oil layer of the suspended particle impact plate is arranged in the sub-diameter chamber and is arranged at intervals from the outlet end of the guide tube. The diameter-division inlet is arranged in the shell, and the outlet end of the flow guiding tube is arranged between the diameter-division inlet and the suspended particle impact plate.

The effect of the present invention is that the suspended particle impact plate can provide the suspended particle sampler to maintain the stability of long-term sampling.

The content of the present invention will be described in detail below:

Preferably, the average diameter of the holes is in the range of 50-150 μm.

Preferably, the thickness of the first silicone oil layer is in the range of 0.9-1.1 mm.

Preferably, the thickness of the glass fiber filter paper is in the range of 0.20-0.25 mm.

Preferably, the first silicone oil layer and the second silicone oil layer are formed of silicone oil with a viscosity range of 30-300 mm ² /s.

Preferably, the material of the porous metal sheet is stainless steel.

Preferably, the opening direction of the dividing inlet is opposite to the opening direction of the outlet end of the draft tube.

Preferably, the draft tube is perpendicular to the horizontal plane of the first silicone oil layer.

Preferably, the dividing entrance is a ring-shaped opening.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are represented by the same numbers.

The present invention will be further illustrated with the following examples, but it should be understood that the examples are only for illustrative purposes and should not be construed as limiting the implementation of the present invention.

Referring to FIG. 1, an embodiment of the suspended particle impact plate 1 of the present invention includes a substrate 11, a porous metal sheet 12, a glass fiber filter paper 13, a first silicone oil layer 14 and a second silicone oil layer 15.

The porous metal sheet 12 is disposed on the substrate 11 and has a plurality of holes 120. The porous metal sheet 12 has a thickness of 3.4 mm, and its material is stainless steel 316. The average diameter of the holes 120 is 100 μm.

The glass fiber filter paper 13 is arranged on the porous metal sheet 12. The thickness of the glass fiber filter paper 13 is 0.21 mm.

The first silicone oil layer 14 is formed on the glass fiber filter paper 13. The thickness of the first silicone oil layer 14 is 1 mm.

The second silicone oil layer 15 is impregnated in the glass fiber filter paper 13 and the holes 120 of the porous metal sheet 12.

The first silicone oil layer 14 and the second silicone oil layer 15 are formed of silicone oil with a viscosity of 100 mm ² /s.

Referring to FIG. 2, an embodiment of the aerosol fractional sampler 2 of the present invention includes a housing 21, a diversion tube 22, an aerosol impact plate 1 as described above, and a fractional inlet 23.

The housing 21 defines a dividing chamber 210 located inside, and includes a sampling port 211 communicating with the outside.

The flow guide tube 22 is disposed in the housing 21 and includes an inlet end 221 connected to the sampling port 211 and an outlet end 222 in the dividing chamber 210.

The first silicon oil layer 14 of the suspended particle impact plate 1 is arranged in the sub-diameter chamber 210 and is arranged at a distance from the outlet end 222 of the guide tube 22. The guide tube 22 is perpendicular to the horizontal plane of the first silicone oil layer 14.

The diameter-division inlet 23 is arranged in the housing 21, and the outlet end 222 of the flow guiding tube 22 is arranged between the diameter-division inlet 23 and the suspended particle impact plate 1. The opening direction of the dividing inlet 23 is opposite to the opening direction of the outlet end 222 of the guide tube 22. The dividing inlet 23 is a ring-shaped opening.

The ambient gas can be collected through the sampling port 211 of the aerosol sub-diameter sampler 2 of the above-mentioned embodiment, and after being accelerated by the guide tube 22, it is blocked by the aerosol impact plate 1 and diverted to the sub-diameter inlet twenty three. The suspended particles with larger inertial mass in the gas will be collected (loaded) due to the impact of the inertial effect on the suspended particle impact plate 1, and the suspended particles with smaller inertial mass in the gas will be brought to the divided diameter entrance along with the gas flow 23, to achieve the diameter of suspended particles.

Taking the aerosol sampler 2 of the above embodiment as the experimental group, and the commercial particle sampler (model B2151250015, coated with lubricating oil) sold by Concentration Technology (FPI) as the control group, the following tests were performed.

[ Sampling error test]

×100%Use the following formula to calculate the sampling error: sampling error =

×100%

( Ⅰ ) Continuous collection for 96 hours, sampling once every 6 hours, taking the sample concentration C ₁ (clean impact surface) of the control group as the comparison benchmark. The average concentration of ambient PM ₁₀ is 26.74±6.53 µg/m ³ , the ambient temperature is 28.61±2.07°C, the relative humidity is 73.41±6.07%, and the ambient wind speed is 1.89±1.00 km/h.

The results of the control group sampling concentration C ₂ (unclean impact surface) show that the average sampling error in 0-60 hours is -3.74±4.7%, and the average sampling error in 66-96 hours is +6.6±7.51%, and exceeds The highest sampling error after 60 hours is +20.9%. It shows that if the impact surface is not cleaned, the PM ₁₀ accumulated on the impact surface will easily cause the suspended particles to bounce, which will cause a significant positive deviation of the sampling concentration.

The results of the experimental group sampling concentration C ₂ (unclean impact surface) show that the average sampling error in 0-60 hours is -2.21±5.03%, and the average sampling error in 66-96 hours is +0.5±3.58%, and exceeds The highest sampling error after 60 hours is only +7.45%. It shows that if the impact surface is not cleaned, the PM ₁₀ accumulated on the impact surface is less likely to cause the suspended particles to bounce, and the positive deviation of the sampling error is lower.

( Ⅱ ) Collect continuously for 35 days, and sample on the 1, 2, 3, 4, 5, 12, 13, 14, 20, 21, 27, 28, 34, 35 days, with the sampling concentration of the control group C ₁ ( Clean the impact surface) as a benchmark for comparison. The average concentration of ambient PM ₁₀ is 21.28±5.42 µg/m ³ , the ambient temperature is 29.28±0.89°C, the relative humidity is 71.45±4.61%, and the ambient wind speed is 1.84±0.46 km/h.

The results of the sample concentration C ₂ (unclean impact surface) of the experimental group show that the average sampling error is +0.01±2.99%, and it has a fairly high consistency compared with the sample concentration C ₁ (clean impact surface) of the control group (C _The linear relationship between _2- C ₁ has a slope of 1.007, an intercept of 0.13 µg/m ³ , and R ² of 0.989). It shows that if the impact surface is not cleaned, it can still effectively avoid the problem of suspended particles bouncing, and the sampling error is quite close to zero.

( III ) Collecting for 14 consecutive days, and sampling on the 14th day, taking the sample concentration C ₁ (clean impact surface) of the control group as the comparison benchmark. The average concentration of ambient PM ₁₀ is 12.4±7.11 µg/m ³ , the ambient temperature is 21.81±1.5°C, the relative humidity is 79.66±5.77%, and the ambient wind speed is 2.84±0.92 m/s.

In the suspended particle sampler of the above embodiment, the suspended particle impact plate sampling concentration C ₂ (unclean impact surface) of the first silicone oil layer 14 and the second silicone oil layer 15 is not provided in the suspended particle sampler. The result shows that the average sampling error is + 10.03%. It is shown that for the sampler without the first silicone oil layer 14 and the second silicone oil layer 15, if the impact surface is not cleaned, long-term sampling will cause the suspended particles to bounce, causing a positive deviation in the concentration.

[ Collection efficiency test ]

( Ⅰ ) Continuous collection for 16 days, the average concentration of ambient PM ₁₀ is 21.74±3.82 µg/m ³ , the ambient temperature is 30.5±0.7℃, the relative humidity is 68.4±5%, and the ambient wind speed is 6.6±3 km/h.

( Ⅱ ) Continuous collection for 23 days, the average concentration of ambient PM ₁₀ is 30.85±19.99 µg/m ³ , the ambient temperature is 20.34±4.0℃, the relative humidity is 75.02±8.27%, and the ambient wind speed is 6.54±0.72 km/h.

【表1】   d_pa50 (µm) GSD CS′ 10.44 1.48 CS(Ⅰ) 10.19 1.57 CS(Ⅱ) 9.76 1.61 ES′ 10.42 1.39 ES(Ⅱ) 10.41 1.43 The collection efficiency is plotted against aerodynamic diameter, and the collection efficiency curves of the control group's clean impact surface CS', the control group's unclean impact surface CS, the experimental group's clean impact surface ES', and the experimental group's unclean impact surface are obtained respectively. ES collection efficiency curve, and calculate d _pa50 (aerodynamic particle size corresponding to 50% collection efficiency) and GSD (geometric standard deviation, calculated using the following formula), and the results are shown in Table 1 below. GSD=

【Table 1】 d _pa50 (µm) GSD CS′ 10.44 1.48 CS(Ⅰ) 10.19 1.57 CS(Ⅱ) 9.76 1.61 ES′ 10.42 1.39 ES(Ⅱ) 10.41 1.43

It can be clearly seen from Table 1 above:

(1) controls the cleaning dirty surfaces CS shock impact face CS _'d pa50 having a significant difference, while the experimental group and the cleaning dirty impact face impact face ES ES' _d pa50 is very close. It shows that if the impact surface is not cleaned, the d _{pa50 of the} control group will decrease with the collection time, while the d _{pa50 of} the experimental group is hardly affected by the collection time.

(2) The GSD of the unclean impact surface CS and the clean impact surface CS' of the control group are significantly different, while the GSD of the unclean impact surface ES and the clean impact surface ES' of the experimental group are close. It shows that if the impact surface is not cleaned, the GSD of the control group will increase significantly with the collection time and deviate significantly from 1. The GSD of the experimental group will be slightly affected by the collection time.

In addition, the unclean impact surface CS (Ⅰ) of the control group had a particle load of 0.93 mg on the 3rd day, which increased to 4.87 mg by the 16th day, and the unclean impact surface CS (Ⅱ) of the control group had reached the 23rd day. , The particle load reached 8.74 mg.

In summary, the aerosol impact plate 1 of the present invention covers the collected aerosols with larger inertial mass by the first silicone oil layer 14, and impregnates the first silicon oil layer with the glass fiber filter paper 13 and the porous metal sheet 12. The second silicone oil layer 15 can prevent the first silicone oil layer 14 from being blown away by the airflow and maintain its impact surface, which can effectively avoid the problem of suspended particles bouncing, and can make the sampling result of the suspended particle sampler 2 of the present invention less Affected by the collection time to maintain the stability of long-term sampling, it can indeed achieve the purpose of the invention.

However, the above are only examples of the present invention. When the scope of implementation of the present invention cannot be limited by this, all simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the patent specification still belong to This invention patent covers the scope.

1: Suspended particle impact board 11: substrate 12: porous metal sheet 120: Hole 13: Glass fiber filter paper 14: The first silicone oil layer 15: The second silicone oil layer 2: Suspended particulate sampler 21: Shell 210: Diameter chamber 211: sampling port 22: Draft tube 221: Import side 222: Exit 23: Divide entrance

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: [Figure 1] is a schematic cross-sectional view of an embodiment of the aerosol impact plate of the present invention; and [Figure 2] is A schematic cross-sectional view of an embodiment of the suspended particulate sampler of the present invention.

1: Suspended particle impact board

11: substrate

12: porous metal sheet

120: Hole

13: Glass fiber filter paper

14: The first silicone oil layer

15: The second silicone oil layer

Claims (10)

A suspended particle impact plate, comprising: a substrate; a porous metal sheet provided on the substrate with a plurality of holes; a glass fiber filter paper provided on the porous metal sheet; a first silicone oil formed on the glass fiber filter paper Layer; and a second silicone oil layer impregnated in the glass fiber filter paper and the holes of the porous metal sheet. The suspended particle impact plate according to claim 1, wherein the average diameter of the holes is in the range of 50-150 μm. The suspended particle impact plate according to claim 1, wherein the thickness of the first silicone oil layer is in the range of 0.9-1.1 mm. The suspended particle impact board according to claim 1, wherein the thickness of the glass fiber filter paper is in the range of 0.20-0.25 mm. The suspended particle impact plate according to claim 1, wherein the first silicone oil layer and the second silicone oil layer are formed of silicone oil with a viscosity range of 30-300 mm ² /s. The suspended particle impact plate according to claim 1, wherein the material of the porous metal sheet is stainless steel. An aerosol split-diameter sampler, comprising: a shell defining a split-diameter chamber located inside, and including a sampling port communicating with the outside; a draft tube arranged in the shell, including a sampling port communicating The inlet end of the aerosol and an outlet end in the sub-diameter chamber; the aerosol impact plate as described in claim 1, the first silicone oil layer of the aerosol impact plate is arranged in the sub-diameter chamber, and The outlet end of the flow guiding tube is arranged at intervals; and a divided inlet arranged in the shell, and the outlet end of the guiding tube is arranged between the dividing inlet and the suspended particle impact plate. The suspended particulate sampler according to claim 7, wherein the opening direction of the diameter dividing inlet is opposite to the opening direction of the outlet end of the guide tube. The suspended particulate sampler according to claim 7, wherein the draft tube is perpendicular to the horizontal plane of the first silicon oil layer. The suspended particle diameter dividing sampler according to claim 7, wherein the diameter dividing inlet is a ring-shaped opening.

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