TWI674400B - Suspended particle impact plate and suspended particle size sampler - Google Patents

Abstract

An suspended particle impact plate 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 disposed on the substrate and has a plurality of holes. The glass fiber filter paper is disposed 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 glass fiber filter paper and the holes of the porous metal sheet. The present invention also provides a suspended particle diameter sampling device, which includes a casing, a diversion tube, the suspended particle impact plate, and a diameter inlet. The outlet end of the deflector is disposed between the diameter-differing inlet and the suspended particle impact plate. The aerosol particle impact plate can provide the aerosol particle diameter sampler to maintain long-term sampling stability.

Description

Suspended particle impact plate and suspended particle diameter sampler

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

The existing suspended particle diameter sampler is suitable for collecting gas containing suspended particles in the surrounding environment, and using the impact plate therein to separate and collect suspended particles with different inertial masses (or aerodynamic particle sizes). However, due to the turbulence of the airflow inside the suspended particle diameter sampler, the collection efficiency is not ideal. Generally, the surface of the impact plate is coated with lubricant 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 subsequent gas entering the diameter sampler will no longer hit the impact plate, but will instead hit the particles deposited on it. As a result, the collection efficiency of suspended particles is significantly reduced, errors in sampling concentration, and the particle size distribution of particles are shifted to small particle diameters. Therefore, after continuous collection, it is often necessary to clean and rinse particles accumulated on the impact plate and recoat Cover with lubricant.

Therefore, an object of the present invention is to provide a suspended particle impact plate, which can overcome the disadvantages of the foregoing 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 disposed on the substrate and has a plurality of holes. The glass fiber filter paper is disposed 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 glass fiber filter paper and the holes of the porous metal sheet.

Therefore, another object of the present invention is to provide a suspended particle diameter sampling device which can overcome the disadvantages of the foregoing prior art.

Therefore, the aerosol particle diameter sampling device of the present invention includes a casing, a flow guiding tube, a aerosol particle impact plate as described above, and a diameter inlet. The casing defines a diameter-reducing chamber located inside, and includes a sampling port communicating with the outside. The diversion tube is disposed in the casing, and includes an inlet end communicating with the sampling port and an outlet end in the diameter chamber. The first silicone oil layer of the suspended particle impact plate is disposed in the diameter chamber and is spaced from the outlet end of the flow guide tube. The split-diameter inlet is disposed in the casing, and the outlet end of the deflector is disposed between the split-diameter 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 diameter sampler to maintain long-term sampling stability.

The following will describe the content of the present invention in detail:

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

Preferably, the thickness of the first silicone oil layer ranges from 0.9 to 1.1 mm.

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

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

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

Preferably, the opening direction of the split-diameter inlet is opposite to the opening direction of the outlet end of the diversion tube.

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

Preferably, the split-diameter inlet 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 described with reference to the following examples, but it should be understood that this example is for illustrative purposes only and should not be construed as a limitation on 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 thickness of the porous metal sheet 12 is 3.4 mm, and the material is stainless steel 316. The average diameter of the holes 120 is 100 μm.

The glass fiber filter paper 13 is disposed on the porous metal sheet 12. The glass fiber filter paper 13 has a thickness of 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 hole 120 of the porous metal sheet 12.

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

Referring to FIG. 2, an embodiment of the suspended particle diameter sampler 2 of the present invention includes a casing 21, a flow guide tube 22, a suspended particle impact plate 1 as described above, and a diameter inlet 23.

The casing 21 defines a diameter-reducing chamber 210 located inside, and includes a sampling port 211 communicating with the outside.

The diversion tube 22 is disposed in the casing 21 and includes an inlet end 221 communicating with the sampling port 211 and an outlet end 222 in the diameter chamber 210.

The first silicone oil layer 14 of the suspended particle impact plate 1 is disposed in the diameter chamber 210 and is spaced from the outlet end 222 of the flow guide tube 22. The diversion tube 22 is perpendicular to a horizontal plane of the first silicone oil layer 14.

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

The ambient gas can be collected through the sampling port 211 of the aerosol particle sampling device 2 of the above embodiment, and after being accelerated through the flow guide tube 22, it is blocked by the aerosol particle impact plate 1 and then diverted to the diameter inlet. twenty three. Suspended particles with large inertial mass in the gas will be collected (loaded) due to inertia impacting the suspended particle impact plate 1, and suspended particles with smaller inertial mass in the gas will be brought to the entrance of the diameter with the air flow 23, thereby achieving the diameter of the suspended particles.

The following test was performed using the suspended particle diameter sampler 2 of the above embodiment as an experimental group, and a particle sampler (model B2151250015, coated with lubricating oil) commercially available from FPI.

[ Sampling error test]

Calculate the sampling error using the following formula: Sampling error = × 100%

( I ) 96 hours of continuous collection, sampling every 6 hours, and taking the sample concentration C ₁ (clean impact surface) of the control group as a comparison benchmark. The average ambient PM ₁₀ concentration 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 during 0-60 hours is -3.74 ± 4.7%, and the average sampling error during 66-96 hours is + 6.6 ± 7.51%, and exceeds The highest sampling error after 60 hours was + 20.9%. It is shown that if the impact surface is not cleaned, the cumulative PM ₁₀ loaded on the impact surface will easily cause the suspended particles to bounce, which will cause a significant positive deviation in the sampling concentration.

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

( Ⅱ ) Collecting for 35 consecutive days, sampling on days 1, 2, 3, 4, 5, 12, 13, 14, 20, 21, 27, 28, 34, and 35, and taking the control group sampling concentration C ₁ ( Clean the impact surface) as a reference. The average ambient PM ₁₀ concentration was 21.28 ± 5.42 µg / m ³ , the ambient temperature was 29.28 ± 0.89 ℃, the relative humidity was 71.45 ± 4.61%, and the ambient wind speed was 1.84 ± 0.46 km / h.

The experimental group sampling concentration C ₂ (unclean impact surface) shows that the average sampling error is + 0.01 ± 2.99%, and it has a fairly high consistency compared with the control group's sampling concentration C ₁ (clean impact surface) (C The slope of the _2- C ₁ linear relationship is 1.007, the intercept is 0.13 µg / m ³ , and R ² is 0.989). It is shown 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 ) Collected continuously for 14 days, sampling was performed on the 14th day, and the sampling concentration C ₁ (clean impact surface) of the control group was used as a comparison benchmark. The average ambient PM ₁₀ concentration is 12.4 ± 7.11 µg / m ³ , the ambient temperature is 21.81 ± 1.5 ℃, the relative humidity is 79.66 ± 5.77%, and the ambient wind speed is 2.84 ± 0.92 m / s.

The suspended particle sampling sampler of the above embodiment is not provided with the suspended particles of the first silicone oil layer 14 and the second silicone oil layer 15 and the sample concentration C ₂ (the impact surface is not cleaned) shows that the average sampling error is + 10.03%. It shows 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, the long-term sampling will cause the suspended particles to bounce and cause a positive deviation in the concentration.

[ Collection efficiency test ]

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

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

The collection efficiency is plotted against the aerodynamic diameter, and the cleanliness impact surface CS ′ of the control group, the clean impact surface CS of the control group, the clean impact surface ES ′ of the experimental group, and the unclean impact surface of the experimental group are obtained. ES collection efficiency curve, and calculated d _pa50 (aerodynamic particle size corresponding to 50% collection efficiency) and GSD (geometric standard deviation, calculated using the following formula). 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 known 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 is shown that if the impact surface is not cleaned, the d _{pa50 of the} control group will decrease with the collection time, and 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 ′ in the control group were significantly different, while the GSD of the unclean impact surface ES and the clean impact surface ES ′ in the experimental group were closer. It is shown that if the impact surface is not cleaned, the GSD of the control group will significantly increase with the collection time and deviate significantly from 1, and 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 by day 3, and increased to 4.87 mg by the 16th day. The control group unclean impact surface CS (Ⅱ) by the 23rd day. The particle load reached 8.74 mg.

In summary, the suspended particle impact plate 1 of the present invention covers the collected suspended particles with a large inertial mass by the first silicone oil layer 14, and impregnates the first suspended particle with the glass fiber filter paper 13 and the porous metal sheet 12. The two silicone oil layers 15 make it difficult for the first silicone oil layer 14 to be 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 diameter 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 in this way, any simple equivalent changes and modifications made in accordance with the scope of the patent application and the content of the patent specification of the present invention are still Within the scope of the invention patent.

1‧‧‧ Suspended particle impact plate

11‧‧‧ substrate

12‧‧‧ porous metal sheet

120‧‧‧ Hole

13‧‧‧ glass fiber filter paper

14‧‧‧ the first silicone oil layer

15‧‧‧Second silicone oil layer

2‧‧‧ aerosol particle diameter sampler

21‧‧‧Shell

210‧‧‧ diameter chamber

211‧‧‧Sampling port

22‧‧‧ Diversion tube

221‧‧‧Import

222‧‧‧Export

23‧‧‧ entrance

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

Claims (10)

A suspended particle impact plate comprises: a substrate; a porous metal sheet disposed on the substrate, having a plurality of holes; a glass fiber filter paper disposed 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 holes of the glass fiber filter paper and the porous metal sheet. The aerosol impact plate according to claim 1, wherein the average diameter of the holes ranges from 50 to 150 μm. The suspended particle impact plate according to claim 1, wherein the thickness of the first silicone oil layer ranges from 0.9 to 1.1 mm. The suspended particle impact plate according to claim 1, wherein the thickness of the glass fiber filter paper is 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 a silicone oil having a viscosity in a range of 30-300 mm ² / s. The suspended particle impact plate according to claim 1, wherein the porous metal sheet is made of stainless steel. A suspended particle resampling sampler includes: a casing defining a resizing chamber located in the interior and including a sampling port communicating with the outside; a deflector disposed in the casing including a sampling port communicating with the sampling port An inlet end and an outlet end in the diameter chamber; a suspended particle impact plate as described in claim 1, the first silicone oil layer of the suspended particle impact plate is disposed in the diameter chamber, and The outlet ends of the deflector tube are spaced apart; and a diameter-division inlet provided in the casing, and the outlet end of the deflector tube is disposed between the diameter-dimension inlet and the suspended particle impact plate. The aerosol particle diameter sampler according to claim 7, wherein an opening direction of the diameter inlet is opposite to an opening direction of an outlet end of the flow guide tube. The aerosol particle diameter sampling device according to claim 7, wherein the diversion tube is perpendicular to a horizontal plane of the first silicone oil layer. The aerosol particle diameter sampling device according to claim 7, wherein the diameter inlet is a ring-shaped opening.