JP2006189324A - Sampling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately measure the concentration of a semivolatile organic compound (SVOC) without causing a quartz filter to be clogged as it has been difficult to accurately measure the SVOC since the quartz filter is clogged with other suspended matter existing in high concentrations while long-time measurement is necessary because the concentration of the SVOC in the air is low. <P>SOLUTION: A piston 5 which is a shield body is moved by a suction pump that utilizes an air pressure difference between air 9 under measurement and the interior of an enclosure 1. By exposing a new collecting surface 4b of the cylindrical quartz filter 4 where no clogging is developed, the collecting area of the quartz filter 4 is automatically changed according to the amount of collected SVOC. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  This invention collects a substance to be measured such as SVOC (Semi Volatile Organic Compounds) floating in the atmosphere, which is a pollutant that causes environmental pollution, with a filter, and the substance to be measured adhered to the filter The present invention relates to a sampling device for extracting and measuring the concentration of these substances to be measured.

  In order to analyze the concentration of a substance to be measured such as SVOC in the atmosphere, in a sampling device for collecting the substance to be measured, a filter such as quartz or a polymer adsorbent is generally used as a filter for collecting these substances. (See, for example, Non-Patent Document 1). The substance to be measured such as SVOC collected by the quartz filter is extracted with a solvent, applied to a gas chromatograph mass spectrometer, and the concentration of the substance to be measured is identified from the collected volume of the atmosphere (for example, patent document) 1).

Journal of Indoor Environment Society Vol. 5, no. 1, pp. 13-22 JP 05-052717 A (2 pages, FIG. 1)

  In the analysis of SVOC or the like to be measured, in the conventional sampling device, the concentration is identified from the collected volume of the atmosphere, but the collection area of the filter is fixed, and the collection area of the filter is small. If the concentration of the substance to be measured or the suspended substance to be measured is high, the filter may be clogged, resulting in an error in the measurement result. Also, the concentration of the substance to be measured is low relative to the collection area of the filter. In this case, there is a problem that it is difficult to measure accurately due to the mixing of other suspended substances during the analysis.

  The present invention has been made to solve the above-described problems. Regardless of the concentration of a substance to be measured in the atmosphere that is a measurement target, the filter does not clog, and the collection area of the filter is reduced. The object is to provide a sampling device to be optimized.

  In order to solve the above-described problems, in the sampling device according to the present invention, the pressure difference between the air to be sucked and the air after passing through the filter is determined by the amount of suspended matter containing the substance to be measured collected by the filter. It is used to automatically change the collection area of the filter.

  The present invention automatically adjusts the collection area of the filter according to the amount of suspended matter containing the substance to be aspirated, so that the concentration can be accurately determined regardless of the substance concentration in the atmosphere to be measured. It becomes possible to identify.

Embodiment 1 FIG.
1 is a cross-sectional perspective view showing a sampling device according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional perspective view showing the operation of the sampling apparatus according to the first embodiment.
In FIG. 1, reference numeral 1 denotes a housing of a sampling device. A lid 2 of the housing 1 is provided with an air inlet 3, and a cylindrical quartz filter 4 made of quartz glass wool is connected to the air inlet 3. Removably fixed so that the outer periphery of one end thereof is in contact with the edge, the piston 5 as a shield is disposed so as to be inscribed in the cylindrical quartz filter 4, and the piston 5 is connected to the housing 1. Are connected by a spring 6 provided in the direction of arrow 7 so as to be movable in the direction of arrow 7. The housing 1 is provided with an exhaust port 8 for connection to an external suction pump (not shown). Reference numeral 9 denotes the collected atmosphere, 10 denotes the atmosphere that passes through the cylindrical quartz filter, and 11 denotes the atmosphere that is discharged from the exhaust port 8 by the suction pump.

Next, an operation of collecting SVOC by a filter in order to measure the SVOC concentration in the atmosphere using the sampling apparatus of the first embodiment will be described with reference to FIG.
In the sampling apparatus configured as described above, the atmosphere 9 in the housing 1 is sucked by an external suction pump (not shown), so that the air 9 is taken into the air inlet 3 of the housing 1 from the outside. However, the atmospheric quartz 10 that passes through the cylindrical quartz filter 4 by the cylindrical quartz filter 4 attached to the intake port 3 collects suspended substances including SVOC as a substance to be measured in the atmosphere, and then filters the atmospheric air 11. Is drawn out through the exhaust port 8 by a suction pump. As shown in FIG. 2 (a), at the start of suction, the collecting surface 4a of the cylindrical quartz filter 4 is not clogged, and the piston 5 is pushed upward by the spring 6, and the SVOC is discharged from the atmosphere 10. Contained suspended matter is collected. As shown in FIG. 2 (b), as the suspended substance containing SVOC in the atmosphere is collected by the cylindrical quartz filter 4, the collection surface 4 a of the cylindrical quartz filter 4 is clogged, and the flow rate of the atmosphere 10. Decreases. Thereby, the atmospheric pressure difference between the atmosphere 9 and the atmosphere 11 in the housing 1 becomes large, and the inside of the housing 1 becomes a negative pressure. In order to increase the flow rate of the atmosphere 10, the piston 5 moves down to the point where the suction force and the pushing-up force of the spring 6 balance, and the new collecting surface 4 b of the cylindrical quartz filter 4 is exposed. As a result, the flow rate of the atmosphere 10 is restored, and the suspended matter containing SVOC is again collected from the atmosphere 10 by the cylindrical quartz filter 4. This operation is continuously repeated, and the piston 5 moves downward. After collecting a predetermined fixed atmosphere, the cylindrical quartz filter 4 is removed, SVOC is extracted from the collected suspended matter with a solvent, and then the amount of SVOC is measured with a gas chromatography mass spectrometer. The concentration is identified from the volume of.

The collection area of the cylindrical quartz filter 4 is determined by the balance between the atmospheric pressure 9 and the pressure difference between the inside of the housing 1 and the pushing force of the spring 6. The ratio of the collection area of the exposed filter is the density of the filter eyes. The strength of the spring 6 and the suction capacity of the suction pump can be freely adjusted.
In this way, depending on the filter's collection capability, a new filter surface can be used, automatically depending on the amount of suspended matter containing SVOC collected without causing the filter to become clogged. In particular, by changing the collection area of the filter, it is possible to identify the SVOC concentration with high accuracy by making the collection amount per unit area of the filter constant.
Furthermore, even if the ratio of suspended substances other than SVOC is large and the amount of SVOC is small, it can be reliably collected by a filter, and there is an effect that the concentration of SVOC can be identified with high accuracy.

Embodiment 2. FIG.
FIG. 3 is a cross-sectional perspective view showing a sampling apparatus according to Embodiment 2 of the present invention.
In FIG. 3, in Embodiment 1, the piston 5 that is a shield is attached so as to be inscribed in the filter 4, but the piston 12 in Embodiment 2 is in contact with the outer periphery of the cylindrical quartz filter 4. It is attached. In the figure, reference numerals 1 to 4 and 6 to 11 denote the same or corresponding parts as in FIG. These functions, operations, etc. are the same as those in FIGS.
Also in the operation in the second embodiment, as in the first embodiment, as the suspended matter containing SVOC in the atmosphere is collected by the cylindrical quartz filter 4, the upper portion of the cylindrical quartz filter 4 is clogged and the atmosphere is The flow rate of 10 decreases. Thereby, the atmospheric pressure difference between the atmosphere 9 and the atmosphere 11 in the housing 1 becomes large, and the inside of the housing 1 becomes a negative pressure. The piston 12 descends as shown by the arrow 7 to the point where the suction force of the pump and the pushing-up force of the spring 6 are balanced to increase the flow rate of the atmosphere 10, and the new collection surface of the cylindrical quartz filter 4 is exposed. As a result, the flow rate of the atmosphere 10 is recovered, and the suspended matter is collected from the atmosphere 10 by the cylindrical quartz filter 4 again. After collecting a predetermined fixed atmosphere, the cylindrical quartz filter 4 is removed, SVOC is extracted with a solvent, the amount of SVOC is measured by a gas chromatography mass spectrometer, and the concentration is identified from the volume of the collected atmosphere. To do.

As described above, in the second embodiment, as in the first embodiment, a new collection surface of the filter can be used in accordance with the collection ability of the filter, and the filter is not clogged. By automatically changing the collection area of the filter according to the amount of suspended matter containing SVOC collected, the concentration per unit area of the filter is made constant, thereby identifying the SVOC concentration with high accuracy. It becomes possible.
In the second embodiment, since the piston 12 is configured to receive the cylindrical quartz filter 4, even if dust is contained in the collected air 9, the piston 12 accumulates on the piston 12 and becomes cylindrical quartz. At the time of replacement of the filter 4, these dusts are not scattered in the housing 1, and there is an effect that cleaning becomes easy.

Embodiment 3 FIG.
4 is a cross-sectional perspective view showing a sampling apparatus according to Embodiment 3 of the present invention.
In FIG. 4, reference numeral 13 denotes a cylinder which is a shielding body attached so that the outer periphery of one end thereof is in contact with the suction port 3 of the lid 2 of the housing 1, and the cylindrical quartz filter 14 is circumscribed on the outer periphery of the cylinder 13. The cylindrical quartz filter 14 is detachably attached to the disk 15. The disk 15 is connected to the housing 1 by a spring 6 and is movably attached in the direction of the arrow 7 and moves integrally with the cylindrical quartz filter 14. In the first embodiment, the piston 5 is movable, but in the third embodiment, the cylindrical quartz filter 14 is movably attached to the cylinder 13. In the figure, reference numerals 1 to 3 and 6 to 11 denote the same or corresponding parts as in FIG. These functions, operations, etc. are the same as those in FIGS.

  The operation in the third embodiment is the same as in the first embodiment, but as the suspended matter containing SVOC in the atmosphere is collected by the cylindrical quartz filter 14, the lower part of the cylindrical quartz filter 14 is clogged. And the flow rate of the atmosphere 10 decreases. Thereby, the atmospheric pressure difference between the atmosphere 9 and the atmosphere 11 in the housing 1 becomes large, and the inside of the housing 1 becomes a negative pressure. To increase the flow rate of the atmosphere 10, the cylindrical quartz filter 14 descends as shown by the arrow 7 to the point where the suction force of the pump and the pushing force of the spring 6 are balanced, and a new collection surface of the cylindrical quartz filter 14 is exposed. To do. As a result, the flow rate of the atmosphere 10 is recovered, and the suspended matter is collected from the atmosphere 10 by the cylindrical quartz filter 14 again. After collecting a predetermined fixed atmosphere, the cylindrical quartz filter 14 is removed, SVOC is extracted with a solvent, the amount of SVOC is measured by a gas chromatography mass spectrometer, and the concentration is identified from the volume of the collected atmosphere. .

As described above, in the third embodiment, as in the first embodiment, a new collection surface of the filter can be used according to the collection ability of the filter, and the filter is not clogged. By automatically changing the collection area of the filter according to the amount of suspended matter containing SVOC collected, the concentration per unit area of the filter is made constant, thereby identifying the SVOC concentration with high accuracy. It becomes possible.
Further, in the third embodiment, as in the second embodiment, the cylindrical quartz filter 14 and the disc 15 are configured to receive, so even if the collected air 9 contains dust, the disc When the cylindrical quartz filter 14 is deposited, the dust does not scatter in the housing 1 and the cleaning becomes easy.

Embodiment 4 FIG.
FIG. 5 is a cross-sectional perspective view showing a sampling apparatus according to Embodiment 4 of the present invention.
In FIG. 5, reference numeral 16 denotes a rectangular cylinder attached so that the outer periphery of one end thereof is in contact with the suction port 3 of the lid 2 of the casing 1, and the plate-like quartz filter 17 is provided on one surface of the rectangular cylinder 16. The plate-like quartz filter 17 is detachably attached to the rectangular tube 16. A piston 18 which is a shield is disposed so as to be inscribed in the rectangular cylinder 16, and the piston 18 is connected by a spring 6 provided between the casing 1 and is movable in the direction of an arrow 7. It is attached. In the first embodiment, the quartz filter 4 has a cylindrical shape, but in the fourth embodiment, the plate-like quartz filter 17 is used. In the figure, reference numerals 1 to 3 and 6 to 11 denote the same or corresponding parts as in FIG. These functions, operations, etc. are the same as those in FIGS.

  The operation in the fourth embodiment is the same as that in the first embodiment, but as the suspended matter containing SVOC in the atmosphere is collected by the plate-like quartz filter 17, the upper part of the plate-like quartz filter 17 is clogged. And the flow rate of the atmosphere 10 decreases. Thereby, the atmospheric pressure difference between the atmosphere 9 and the atmosphere 11 in the housing 1 becomes large, and the inside of the housing 1 becomes a negative pressure. To increase the flow rate of the atmosphere 10, the square cylinder 16 descends as shown by the arrow 7 to the point where the suction force of the pump and the pushing force of the spring 6 are balanced, and a new collection surface of the plate-like quartz filter 17 is exposed. As a result, the flow rate of the atmosphere 10 is recovered, and the suspended matter is collected from the atmosphere 10 by the plate-like quartz filter 17 again. After collecting a predetermined constant air, the plate-like quartz filter 17 is removed, SVOC is extracted with a solvent, the amount of SVOC is measured by a gas chromatography mass spectrometer, and the concentration is identified from the volume of the collected air. .

As described above, in the fourth embodiment, as in the first embodiment, a new collection surface of the filter can be used according to the collection ability of the filter, and the filter is not clogged. By automatically changing the collection area of the filter according to the amount of suspended matter containing SVOC collected, the concentration per unit area of the filter is made constant, thereby identifying the SVOC concentration with high accuracy. It becomes possible.
Further, in the fourth embodiment, the plate-like quartz filter 17 can be used, and replacement is easy, and there is an effect that an inexpensive filter can be used.
Further, in the fourth embodiment, the case where one plate-like quartz filter is attached to one surface of a rectangular cylinder has been described, but the same effect can be obtained even when two plate-like quartz filters are attached to two or more surfaces. Needless to say.

In the first to fourth embodiments, the casing 1, the pistons 5 and 12, the spring 6, and the disk 15 are prevented from adhering floating substances such as SVOC, and to avoid the influence of corrosive gas contained in the atmosphere. Stainless steel with less corrosion is desirable. As the material of the filter, the case where quartz glass wool containing no impurities is used has been described, but it may be other than quartz. For example, if it is made of fluororesin, water repellency is good and the humidity is high. It is effective in the atmosphere. Further, the spring may be replaced with one having an equivalent function.
In the above description of the first to fourth embodiments, the case where the sampling device is used vertically is described. However, the sampling device may be used sideways, and the position of the exhaust port is also opposite to the surface of the intake port. It may be attached. Although the case where the shielding area of the shield or the filter is automatically changed according to the pressure difference has been described, there is an effect even when the filter or the filter is manually changed every certain time.

  In the first to fourth embodiments, the sampling device for collecting SVOC has been described. However, it can be used for collecting other floating substances such as POM (Particulate Organic Matter). Nor.

1 is a cross-sectional perspective view showing a sampling device in Embodiment 1. FIG. FIG. 3 is a cross-sectional perspective view showing the operation of the sampling device in the first embodiment. FIG. 6 is a cross-sectional perspective view showing a sampling device in a second embodiment. FIG. 10 is a cross-sectional perspective view showing a sampling device in a third embodiment. FIG. 10 is a cross-sectional perspective view showing a sampling device in a fourth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Case 3 Intake port 4, 14 Cylindrical quartz filter 5, 12, 18 Piston 6 Spring 8 Exhaust port 13 Cylinder 16 Rectangular cylinder 17 Plate-like quartz filter

Claims (5)

A sealed housing having an inlet and an exhaust, and
A filter disposed in a housing for adsorbing suspended solids from the air taken in from the air inlet;
A shield that blocks a part of the collecting surface of the filter;
A sampling device characterized in that either the filter or the shield is movable. The sampling apparatus according to claim 1, wherein either the shield or the filter is moved in accordance with a pressure difference between the atmosphere and the inside of the housing. The sampling apparatus according to claim 1, wherein a spring is attached between the shield and the housing. The sampling apparatus according to claim 1, wherein a spring is attached between the filter and the housing. The sampling apparatus according to any one of claims 1 to 4, wherein the filter is made of quartz glass wool.

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