JP3799501B2 - Quantitative sampling device - Google Patents

Description

The present invention relates to a quantitative sampling apparatus suitable air body is used in combination with a suitable air pollution measuring device was used to obtain such a concentration of atmospheric contaminants.

  Conventionally, as a measuring device that automatically measures the concentration of pollutants in the atmosphere, for example, a predetermined amount of a reagent (absorbing liquid) that absorbs pollutants is placed in a container, and the reagent in the container is placed in the liquid. Developed one that uses air sampling pumps to send air to measure the concentration of contamination, absorbs contaminants in the air, and monitors and measures the change state of the reagent (coloring state, etc.) Yes. According to such a measuring device, the amount of pollutant absorbed by the absorbing liquid can be determined from the change of the absorbing liquid and the amount of the absorbing liquid used, and if the amount of air pumped in can be determined, The concentration of pollutants in the air can be obtained from the ratio between the quantity and the quantity of pollutants.

  However, such a measuring apparatus has a disadvantage that there are many errors in the measured density data. That is, the air sampling pump has poor accuracy in the amount of air to be collected, and an error of about ± 7% is allowed with respect to the set air sampling amount. When an error of ± 7% occurs in the amount of air collected in this way, an error of about ± 7% occurs in the measured concentration value, and it is difficult to measure an accurate concentration. Here, if an accurate air sampling amount detector is attached to the air sampling pump, the measurement accuracy is improved. However, the accurate air sampling amount detector is complicated and very expensive. Yes, it was not used in this type of measuring device.

  In addition, if air is put into a container with a certain volume in advance and the measurement is performed, the amount of air used for measurement can be obtained accurately, but if the amount of air used for measurement is large, a large container is used. It is necessary and not practical.

  In addition, in order to automatically measure the concentration of pollutants, it is necessary to automatically replenish a certain amount after discharging the pollutant absorption liquid used for the measurement. The configuration for that was also complicated.

  In addition, in the case of such a measuring apparatus, there is a disadvantage that a large amount of an absorbing solution that absorbs contaminants is used. In other words, without a certain amount of absorbing liquid, it is not possible to take sufficient contact time between the air sent into the absorbing liquid by the pump and the absorbing liquid, and to completely absorb the pollutants in the air. Can not. Therefore, a certain amount of the absorbing liquid that absorbs the contaminant is required.

The purpose of the present invention is that the collection of a certain amount of gas such as air to provide a quantitative sampling device can be accurate.

  As shown in FIG. 2, for example, the gas sampling device of the present invention includes a pipe 5 arranged substantially vertically, and first and second repellents attached to the pipe 5 at a certain distance. Tubes partitioned by the aqueous porous membranes 11 and 12, the liquids 16 and 17 disposed on the respective water-repellent porous membranes 11 and 12, and the first and second water-repellent porous membranes 11 and 12. A reciprocating body 13 and 14 that sucks a predetermined amount of gas from the space inside the tube and then discharges the sucked gas to the tube. A predetermined amount is sucked from the lower side of the tube 5 by the movement of the reciprocating body 13 and 14. Then, it is discharged from the upper side.

  According to the gas quantitative sampling apparatus of the present invention, it is constituted by the first and second water-repellent porous membranes attached at a certain distance in the middle of the pipe arranged substantially vertically and the reciprocating moving body. Thus, quantitative gas sampling can be performed with a simple configuration.

  According to the gas quantitative sampling apparatus of the present invention, it is constituted by the first and second water-repellent porous membranes attached at a certain distance in the middle of the pipe arranged substantially vertically and the reciprocating moving body. Thus, quantitative gas sampling can be performed with a simple configuration.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a diagram showing the overall configuration of the air pollution measuring device of this example. In FIG. 1, reference numeral 1 denotes a pipe. Inside the pipe 1, a tube (hereinafter referred to as a Teflon tube) 2 made of Teflon, which is a water-repellent porous film, is disposed. This Teflon tube 2 uses a very thin tube having a diameter of about 1 to 2 mm, and the pipe 1 has a diameter of several mm so that a slight gap is generated between the tube 2 and the tube 2 when the Teflon tube 2 is stored. The pipe 1 containing the Teflon tube 2 is used in an upright state (or in a state where there is a height difference between one end and the other end even if it is not in an upright state). The length L of the pipe 1 is at least about 20 cm, preferably 50 cm or more, depending on the air flow rate. Although not shown, when it is difficult to hold the pipe 1 containing the Teflon tube 2 in a predetermined state such as an upright state, the position may be maintained by some auxiliary member.

  The absorbing liquid supply container 3 is connected to the Teflon tube 2 at the upper end of the pipe 1, and the quantitative sampling unit 20 is connected to the Teflon tube 2 at the lower end of the pipe 1. The absorption liquid supply container 3 stores a liquid containing a reagent that absorbs a predetermined air pollutant (hereinafter referred to as an absorption liquid) and supplies the absorption liquid into the connected Teflon tube 2.

  An air intake port 4 is provided at the lower end of the pipe 1, an air discharge pipe 5 is connected to the upper end, and an air suction unit 10 is attached in the middle of the air discharge pipe 5. And the front-end | tip part of this air exhaust pipe 5 becomes the air exhaust port 6. FIG.

  Here, when the details of the air suction unit 10 are shown in FIG. 2, the air discharge pipe 5 at the location where the air suction unit 10 is attached is installed in an upright state, and the pipes above and below the installation location of the air suction unit 10. 5, filters (hereinafter referred to as “Teflon filters”) 11 and 12 made of Teflon, which is a water-repellent porous film, are arranged. A small amount of liquid 16 or 17 that covers the surface of the filter (for example, a non-volatile liquid having a high surface tension) is injected on each of the Teflon filters 11 and 12.

  The air suction part 10 connected to the space in the air discharge pipe 5 partitioned by the Teflon filters 11 and 12 is composed of a cylinder part 13 and a piston part 14 inserted into the cylinder part 13. By extracting the piston portion 14 inserted into the cylinder portion 13 as shown by an arrow M1, a space 15 connected to the air discharge pipe 5 is created, and the air in the pipe 5 is sucked by the volume of the space 15. The Then, as shown by the arrow M2, the air in the space 15 is discharged into the pipe 5 by inserting the piston portion 14 in the reverse direction.

  The pipe 5 is provided with Teflon filters 11 and 12 which are water-repellent porous membranes that allow only gas to pass but not liquid, so that the pipe 5 is sucked from the lower side and discharged to the upper side. become. That is, suction is performed by extracting the piston portion 14 in the direction indicated by the arrow M1, but at this time, introduction of air from the upper side of the pipe 5 is blocked by the water 17 disposed on the upper Teflon filter 12. Is done. The water 16 is also disposed on the lower Teflon filter 11, but the water 16 separates from the surface of the Teflon filter 11 due to the force acting when sucked, as indicated by arrows a and b. Air is introduced from below the pipe 5.

  The sucked air is discharged by inserting the piston portion 14 in the direction indicated by the arrow M2. At this time, the water 16 disposed on the lower Teflon filter 11 is used to lower the pipe 5 below. Air discharge to the side is prevented. Then, the water 17 disposed on the lower Teflon filter 12 is separated from the surface of the Teflon filter 12 by the force acting when discharged, and from the upper side of the pipe 5 as indicated by arrows c and d. Air is exhausted.

  Therefore, by reciprocating the piston portion 14, the air sucked from the lower side of the pipe 5 is discharged from the upper side of the pipe 5, and there is no air flow in the opposite direction. Then, air is sucked and discharged by the volume of the space 15 generated by the stroke for reciprocating the piston portion 14. Here, it is set as the capacity | capacitance which can attract | suck the air in the pipe 1 by attraction | suction by one movement of the piston part 14. FIG.

  Since the air discharge pipe 5 is connected to the upper end of the pipe 1, the air discharge pipe 5 acts to suck the air inside the pipe 5, and the air taken in from the air intake 4 at the lower end of the pipe 1 is 1 is discharged from an air discharge port 6 at the tip of the air discharge pipe 5.

  Next, the details of the quantitative sampling device 20 connected to the lower end of the Teflon tube 2 are shown in FIG. This fixed quantity collection part 20 is comprised by the container of predetermined volume (it is set as the capacity | capacitance which can accommodate the liquid in the Teflon tube 2 here), The liquid intake 21 is in the upper part, The valve 22 is provided in this liquid intake 21. Is provided. Then, by opening the valve 22, the liquid (absorbing liquid) in the Teflon tube 2 from the liquid intake port 21 can be taken into the quantitative sampling unit 20. In addition, a liquid discharge port 23 is provided on the lower side, and a valve 24 is also provided in the liquid discharge port 23. Then, by opening the valve 24, the liquid in the quantitative sampling unit 20 can be discharged.

  In addition, a Teflon filter 26 that is a water-repellent porous film that allows only gas to pass and does not allow liquid to pass therethrough is attached to a predetermined portion 25 at the upper portion of the quantitative sampling unit 20, and the quantitative sampling unit is provided via the Teflon filter 26. Air can be conducted between the inside and the outside of the container 20.

  Here, with reference to FIG. 4, the operation | movement which collect | recovers fixed quantity liquid with this fixed quantity collection part 20 is demonstrated. First, as shown in FIG. 4A, when the upper valve 22 is opened while the lower valve 24 is closed, the liquid in the Teflon tube 2 accumulates in the space 27 in the quantitative sampling unit 20. At this time, the air in the space 27 in the quantitative sampling unit 20 passes through the Teflon filter 26 and escapes outside the container. Therefore, finally, as shown in FIG. 4B, the space 27 in the quantitative sampling unit 20 is completely filled with the liquid, and the upper valve 22 is closed in this state.

  Then, when discharging the liquid collected in the space 27 in the quantitative collection unit 20, only the lower valve 24 is opened. In this way, as shown in FIG. 4C, external air can enter the space 27 through the Teflon filter 26, and the internal liquid can be completely discharged from the liquid discharge port 23.

Next, the operation of measuring the air pollution by the air pollution measuring apparatus having the configuration of the present embodiment described above will be described. First, an absorbing liquid containing a reagent that absorbs the pollutant to be measured is put into the absorbing liquid supply container 3. At this time, the valves 22 and 24 of the quantitative sampling unit 20 are closed.

  By putting this absorbing liquid, the Teflon tube 2 in the pipe 1 is filled with the absorbing liquid. Since the Teflon tube 2 has a property of allowing air to pass through, the air in the tube 2 can escape to the outside, and the tube 2 can be completely filled with the absorbing solution.

  In this state, the air suction part 10 is moved in the direction in which the biston part 14 is extracted to suck a predetermined amount of air. The suction amount at this time is set to an amount sufficient to extract air from the pipe 1. By performing this suction, the air taken in from the air intake 4 at the lower end of the pipe 1 is filled in the pipe 1. Then, the air filled in the pipe 1 and the absorbing liquid come into contact with each other through the Teflon tube 2, and contaminants in the air are absorbed by the absorbing liquid.

  Then, the valve 22 of the quantitative sampling unit 20 is opened, and the absorption liquid in the Teflon tube 2 is sampled in the quantitative sampling unit 20. Then, the state of the absorption liquid collected in the quantitative collection unit 20 is detected, and the amount of contaminants collected is measured. At this time, conventionally known measurements such as colorimetric measurement, electrical characteristic measurement, and light scattering state measurement are performed. Note that this measurement may be performed inside the container constituting the quantitative sampling unit 20, or the quantitative value collected by opening the valve 24 of the quantitative sampling unit 20 is discharged to another measurement container and measured. You may make it do.

By measuring in this way, the amount of contaminants collected can be determined, and the amount of air sucked by the air suction unit 10 and the amount of absorption liquid collected by the quantitative sampling unit 20 can also be determined. The concentration of can be accurately determined. In this case, in this example, the pipe 1 which is the place where the air and the absorbing liquid are brought into contact with each other is made sufficiently long. Can be absorbed. Figure 5 is a diagram showing the pipe 1 and the length L and the collecting state of the contaminants, almost completely it can be collected contaminants in the air at a predetermined length L ₁ or more, the pipe By setting the length of ₁ to L ₁ or more, accurate measurement is possible. As an example of this length L ₁ , for example, to measure nitrogen oxide NO ₂ as a pollutant, a Zarman liquid is filled into a Teflon tube 2 having an inner diameter of 1 mm and sucked using an absorbing liquid. When the air flow rate was 12 ml per minute, most of the sample was absorbed into the absorbent at 20 cm and almost completely absorbed at 50 cm. The amount of the absorbing liquid at this time is about 0.4 ml.

  Therefore, according to the measuring apparatus of this example, measurement can be performed with a very small amount of the absorbing liquid. Compared with the conventional measuring apparatus, the measurement can be performed in an amount of 1/10 or less, and the absorption liquid can be saved accordingly. In addition, the amount of air sucked by the air suction unit 10 can be accurately determined by the stroke in which the piston unit 14 is moved, and the amount of absorption liquid sampled by the quantitative sampling unit 20 can also be accurately determined by the volume of the sampling unit 20. The concentration can be detected with very high accuracy. The amount of air sucked by the air suction unit 10 having the configuration of this example can be detected with an accuracy of 0.1% or more, and the amount of the absorbing liquid collected by the quantitative sampling unit 20 can also be detected with the same accuracy.

  It should be noted that the absorption liquid exchange (ie, opening / closing control of the valves 22 and 24) by the quantitative sampling unit 20 and the suction by the air suction unit 10 (ie, the reciprocating movement of the piston unit 14) are continuously and automatically performed every predetermined time. Therefore, continuous measurement for a long time can be performed continuously.

  FIG. 6 is a diagram showing another configuration of the air suction unit. In the figure, 30 indicates a container having a volume corresponding to the amount of air to be sucked, and the container 30 has a lid 31. The air discharge pipe 5 connected to the pipe 1 shown in FIG. 1 is penetrated, and the tip 5 a of the pipe 5 is set inside the container 30. Further, a very thin tube 33 having a diameter of about 1 mm is passed through the lid 31. In this case, the tip 33 a of the tube 33 on the inside 32 side of the container 30 is extended to the bottom of the container 30. Furthermore, the tip 33 b of the tube 33 outside the container 30 is set at a position lower than the bottom of the container 30.

  In the initial state, the interior 32 of the container 30 is completely filled with some liquid such as water. When the measurement is started, the liquid in the inside 32 of the container 30 is sucked from the distal end portion 33 b of the tube 33 outside the container 30, and the liquid is sequentially discharged to the outside through the tube 33. At this time, once draining is started for the first time, the tip 33b is lower than the bottom of the container 30, and thereafter the liquid is automatically drained until the liquid in the interior 32 of the container 30 is almost completely removed. Since the diameter of 33 is made very thin, it takes time (for example, 1 hour) until it is completely drained.

  Then, according to this drainage, air is sucked into the interior 32 of the container 30 from the air discharge pipe 5 side, and the liquid in the interior 32 of the container 30 is almost completely drained, so that the air proportional to the amount of drainage is pipe 1. It is sucked from the side.

  By using the air suction section having the structure shown in FIG. 6, air can be automatically sucked continuously for a relatively long time without using any power, and accurate measurement can be performed even in a place without a power source. It becomes possible.

  In the above-described embodiment, the liquid is used for absorbing the pollutant. However, the absorbing liquid may be used by soaking it in some substance. For example, as shown in FIG. 7, a glass fiber supply unit 41 is connected to the upper part of the pipe 1, a glass fiber winding unit 42 is connected to the lower part, and a strip-shaped glass fiber 43 drawn out from the glass fiber supply unit 41. May be wound by the glass fiber winder 42. In this case, the glass fiber 43 is preliminarily impregnated with an absorbing solution so that the glass fiber comes into contact with air in the pipe 1. The glass fiber 43 is automatically fed by the length of the pipe 1 every predetermined time by a predetermined feeding mechanism 44 and wound. Other parts are configured in the same manner as the measuring apparatus shown in FIG.

  Even in such a configuration, it is possible to accurately measure the concentration of the pollutant as in the above-described embodiment. Although glass fiber is used here, the absorbent may be soaked in another substance as long as it has chemical resistance. Moreover, the spherical object which rolls easily may be sufficient.

Further, it is possible to detect the amount of contaminants in the air using only the air suction unit 10 described above. That is, in the above-described embodiment, a liquid such as water is arranged on the Teflon filters 11 and 12 provided in two places in the air suction portion 10 shown in FIG. The amount of pollutant can be detected by inserting an absorbing solution that absorbs. That is, the absorbing liquid disposed on the lower filter 11 is defined as the first absorbing liquid, and the absorbing liquid disposed on the upper filter 12 is defined as the second absorbing liquid, and the contaminants absorbed in the first absorbing liquid. Q ₁ , and the amount of contaminants absorbed in the second absorption liquid as q ₂ , the total amount q _{0 of} contaminants contained in the air can be obtained by the following equation [Equation 1].

Then, the concentration can be detected from the total amount q ₀ obtained and the amount of air sucked by the suction portion.

  In addition, since an accurate amount of air can be collected by the air suction unit described above, a so-called differential pollutant measuring device can be configured. FIG. 8 is a diagram showing an example of this case. In the figure, reference numeral 50 denotes an air suction part 50, which is partitioned by a movable film 51 driven by some driving means (not shown). Each of the movable film 51 moves between the first air chamber 52 and the second air chamber 53 as indicated by a broken line. The amount of air in the air chambers 52 and 53 changes. The pipe 71 connected to the first air chamber 52 side is provided with Teflon filters 54 and 55 up and down, and the pipe 72 connected to the second air chamber 53 side is arranged up and down. Teflon filters 56 and 57 are arranged. A small amount of liquid 61, 62, 63, 64 is disposed on each Teflon filter 54, 55, 56, 57, and the amount of air in each air chamber 52, 53 changes as the movable film 51 moves. As a result, air is collected above the pipes 71 and 72 by an amount corresponding to the change in the air amount in the air chambers 52 and 53.

  In addition, an ozone decomposing machine 73 and an air pollution measuring device 74 are connected to the lower side of one pipe 71 from which air is collected in this way, and the air is sucked by the air sucking unit 50, so that this suction is performed. After the generated atmosphere is decomposed by the ozonolysis device 73, it is supplied to an air pollution measuring device 74 that measures nitrogen oxides and the like. An air pollution measuring device 75 for measuring nitrogen oxides is connected to the lower side of the other pipe 72 from which air is collected.

With this configuration, the ozone O ₃ air is determined by the difference between the amount of pollutants detected by one air pollution measuring device 74 and the amount of pollutants detected by the other air pollution measuring device 75. The amount inside can be measured accurately. That is, in the past, when measuring ozone O ₃ , nitrogen oxides NO _{2 and} NO acted as interfering substances, resulting in errors in the measured values. In the example of FIG. From the difference between the detected value including the substance and the substance to be measured and the detected value of only the interfering substance, the amount and concentration of ozone O ₃ that is the substance to be measured can be accurately measured. Also, one air pollution measuring device 74 can accurately measure the amount of only nitrogen oxides. In the case of this example, the amount of air used for detection by one nitrogen oxide detector 74 and the amount of air used for detection by the other nitrogen oxide detector 75 are exactly equal. Therefore, the differential concentration measurement can be performed accurately.

  In addition, the shape and size of each part shown in the above-described embodiments are merely examples, and are not limited to these examples. For example, the air suction unit shown in FIG. 2 is configured to be sucked by the reciprocating movement of the piston, but may be formed of another substance that functions in the same manner (for example, the reciprocating movement of the bellows-like member).

  In addition, the means for quantitatively sucking air described as the air suction section and the means for quantitatively collecting liquid described as the quantitative sampling section of the absorbing liquid are the same as the quantitative sampling means of gas and the quantitative sampling of liquid, respectively. Of course, it can also be used as a means.

It is a block diagram which shows one Example of the air pollution measuring apparatus of this invention. It is sectional drawing which shows the air suction part of one Example. It is sectional drawing which shows the reagent fixed quantity collection part of one Example. It is explanatory drawing which shows collection operation | movement of the reagent fixed quantity collection part of one Example. It is a characteristic view which shows the contaminant collection state by the reagent fixed quantity collection part of one Example. It is sectional drawing which shows the air suction part by the other Example of the air pollution measuring apparatus of this invention. It is a block diagram which shows the further another Example of the air pollution measuring apparatus of this invention. It is a block diagram which shows the example which applied the quantitative air sampling apparatus of this invention to the differential type | formula measuring apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pipe 2 Teflon tube 3 Absorption liquid supply container 4 Air intake port 5 Air exhaust pipe 6 Air exhaust port 10,50 Air suction part 11,12,26,54,55,56,57 Teflon filter 20 Fixed amount sampling part 21 Liquid intake Mouth 22, 24 Valve 23 Liquid outlet 43 Glass fiber

Claims (1)

  Tubes arranged substantially vertically, first and second water-repellent porous membranes attached at a certain distance in the middle of the tubes, and liquid disposed on each of the water-repellent porous membranes And a reciprocating moving body that sucks a predetermined amount of gas from the space inside the tube partitioned by the first and second water-repellent porous membranes, and then discharges the sucked gas to the tube. A quantitative sampling device for gas, wherein a predetermined amount is sucked from the lower side of the tube and discharged from the upper side by moving the moving body.

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