JP2008039634A - Gas quantity measuring device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas quantity measuring device capable of acquiring automatically a highly-reliable measurement result, while having a simple configuration. <P>SOLUTION: The device includes a water tank 3 storing water beforehand; a measuring cylinder 4 arranged at such a height that an opening part is dipped into water in the water tank with an inverted attitude wherein the opening is faced downward on the water tank, wherein liquid in the water tank is stored inside beforehand to a furthermore upper level than the opening; and a gas pipe 6 for supplying gas into the measuring cylinder. The device is characterized by including an electronic force balance 2 on which the water tank is placed, and a support stand 5 for supporting the measuring cylinder on the water tank in the state of the inverted attitude so that a mass applied onto the electronic force balance is increased as much as a mass portion of pushed-out water when the water is pushed out from the measuring cylinder into the water tank. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a gas amount measuring method for measuring a gas amount and a gas amount measuring apparatus suitable for carrying out the gas amount measuring method.

  FIG. 4 reproduces the main part of the gas amount measuring device disclosed in Patent Document 1. This device is arranged in a water tank 11 in which water is stored in advance, and in an inverted posture with the opening 12a facing downward on the water tank 11, at a height at which the portion of the opening 12a is immersed in the water in the water tank 11. Includes a graduated cylinder 12 in which water in the water tank 11 is accommodated in advance up to a level above the opening 12a, and a gas pipe 13 for supplying gas into the graduated cylinder 12. The measuring cylinder 12 is supported and fixed to the water tank 11 so as not to fall down.

  According to this gas amount measuring device, with the supply of gas from the gas pipe 13, the supplied gas is replaced with water in the measuring cylinder 12, and the replaced water is pushed out from the measuring cylinder 12 to the water tank 11. As a result, the liquid level of the measuring cylinder 12 is lowered. For this reason, the amount of gas supplied from the gas pipe 13 can be measured by visually reading the level of the liquid level of the graduated cylinder 12 from a scale provided in advance on the graduated cylinder 12.

  In addition to the gas amount measuring device, for example, Patent Literature 2 discloses a device that collects a gas to be measured by water replacement. In any of the apparatuses, the amount of gas collected in a container (for example, a graduated cylinder) by water replacement is measured by visually reading a scale attached to the container.

  However, in each of the above-described devices, the level of the liquid level is visually read, so that the scale may be read erroneously and the reading accuracy may vary depending on the measurer. In addition, when measuring temporal changes in the amount of gas generated from a sample, it is necessary to read and record the scale of the graduated cylinder at certain time intervals, so the operator must be restrained for a long time. .

Thus, for example, Patent Document 3 discloses an electrode that is caused by disposing a pair of electrodes facing a collection container that collects gas by a water displacement method, and the liquid level of the collection container decreases as the gas is collected. It is proposed to measure the amount of gas based on the change of capacitance between. The change in capacitance between the electrodes uses an oscillator that applies an AC signal between the electrodes, a counter that measures the frequency of the AC signal output from the oscillator, and a display device that outputs the detection result of the counter. Measured.
Japanese Patent Laid-Open No. 2-95446 (FIG. 2) Japanese Patent No. 3098608 (FIG. 2) JP-A-6-317446 (FIG. 1)

  According to the apparatus of Patent Document 3, since the gas amount can be automatically measured, it is not necessary to restrain the measurer for a long time, and the measurement result of the gas amount is displayed and output, so the level of the liquid level is read visually. Although there is an advantage that work is unnecessary, a collection container having a structure with electrodes attached is necessary, and in order to measure the capacitance between the electrodes, an oscillator, a frequency counter, and a display device In addition, since at least wiring for connecting them is necessary, there is a problem that the number of parts is large and the apparatus configuration is likely to be complicated.

  An object of the present invention is to provide a gas amount measurement technique capable of obtaining a measurement result with higher reliability than when the level of the liquid level is visually read while using an apparatus having a simple configuration. Another object of the present invention is to provide a gas amount measuring technique capable of automatically measuring a gas amount while using a device having a simple configuration.

  According to one aspect of the present invention, the apparatus includes a gas collection container (4) in which a liquid is previously stored, and a gas pipe (6) that supplies gas into the gas collection container. With the gas supply, the gas supplied is replaced with the liquid in the gas collection container, and the substituted liquid is pushed out of the gas collection container. A gas amount measuring device is provided, comprising a mass meter (2) for measuring the mass of the liquid pushed out of the gas collection container.

  According to another aspect of the present invention, a liquid tank (3) in which liquid is stored in advance, and an inverted posture with the opening directed downward on the liquid tank, at least a portion of the opening is the liquid in the liquid tank. A gas collection container (4) which is arranged so as to be immersed and in which the liquid in the liquid tank is stored in advance up to a level above the opening, and a gas which supplies gas into the gas collection container A pipe (6), and with the supply of the gas from the gas pipe, the supplied gas is replaced with the liquid in the gas collection container, and the substituted liquid is transferred from the gas collection container In the gas amount measuring device configured to be pushed out into the liquid tank, when the liquid is pushed out from the gas collecting container to the mass meter (2) on which the liquid tank is placed, The mass applied to the mass meter increases by the mass of the extruded liquid. Sea urchin, the support base for supporting the tank on the gas collecting container in the state of the inverted posture (5) and the gas amount measuring device characterized by comprising a are provided.

  It is possible to reflect the change in the supply amount of the gas to be measured in the change in the measurement value of the mass meter. When grasping the change in the gas supply amount from the output of the mass meter, it is not necessary to visually check the position of the liquid level and the position of the scale, so compared to the conventional technology that required such work, The possibility of erroneous reading and the possibility of variations in reading accuracy by the measurer can be reduced, and a highly reliable measurement result can be obtained. In addition, since the gas amount is measured based on the mass, an electrode, an oscillator, or the like is not required and the apparatus configuration is simplified as compared with the conventional technique in which the gas amount is measured based on the capacitance. .

  FIG. 1 shows a gas amount measuring apparatus according to an embodiment of the present invention. For example, a water tank 3 made of a beaker is placed on an electronic balance 2 connected to the personal computer 1 so as to be able to perform data communication with an RS232C cable. Water is stored in the water tank 3 in advance. On the water tank 3, the graduated cylinder 4 is disposed in an inverted posture with the opening 4 a directed downward, at least at a height at which the opening 4 a is immersed in the water in the water tank 3. In the graduated cylinder 4, the water in the water tank 3 is stored in advance up to a level above the opening 4a. The water in the measuring cylinder 4 and the water in the water tank 3 can freely flow through the opening 4 a of the measuring cylinder 4.

  A support base 5 supports the graduated cylinder 4. Specifically, the support base 5 has a pair of beams 5a and 5b that are wider than the diameter of the body portion of the graduated cylinder 4 and are spaced apart from the diameter of the bottom seat plate 4b of the graduated cylinder 4. The measuring cylinder 4 is fitted between the beams 5a and 5b with the bottom seat plate 4b placed on the beams 5a and 5b.

  A gas pipe 6 is inserted into the graduated cylinder 4 from the opening 4 a via the water tank 3. The gas pipe 6 is connected to a gas source 7 that generates a gas to be measured. The gas source 7 includes a sample 7a adjusted to generate gas, an airtight sample container 7b containing the sample 7a, and the sample container 7b. The temperature of the sample 7a is adjusted to a desired temperature. It comprises a temperature regulator 7c. A gas pipe 6 is connected to the sample container 7b. In addition, the temperature regulator 7c consists of a thermostat, for example. Needless to say, when the temperature control of the sample 7a is unnecessary, the temperature regulator 7c is unnecessary.

  The operation of the gas amount measuring apparatus described above is as follows. As a premise, the measurement result of the electronic balance 2 is output to the personal computer 1 in real time as mass data. When gas is generated by the gas source 7, the generated gas is discharged into the measuring cylinder 4 through the gas pipe 6. The gas discharged from the gas pipe 6 is collected in the graduated cylinder 4 by water replacement, and the water replaced with the collected gas is pushed out from the graduated cylinder 4 to the water tank 3. That is, each time gas is discharged from the gas pipe 6, a volume of water corresponding to the volume of the discharged gas is pushed out from the measuring cylinder 4 to the water tank 3.

  Since the support base 5 supports the graduated cylinder 4, in the state of FIG. 1, the mass of the graduated cylinder 4 and the water that is higher than the liquid level of the water tank 3 among the water accommodated in the graduated cylinder 4. The mass is not applied to the electronic balance 2, but each time water is pushed out from the graduated cylinder 4 to the water tank 3, the mass applied to the electronic balance 2 is increased by the amount of the pushed-out water. Since the volume of water corresponding to the volume of the gas discharged from the gas pipe 6 is pushed out from the measuring cylinder 4, the amount of gas discharged from the gas pipe 6 (from the time change of the measured value of the electronic balance 2) Change in volume) over time.

  The conventional apparatus shown in FIG. 4 is different from the apparatus of FIG. 1 in that it does not include a mass meter. However, even if the water tank 11 is placed on an electronic balance in FIG. Since the load of the measuring cylinder 12 is applied to the water tank 11, the measured value of the electronic balance does not change when water is pushed out from the measuring cylinder 12 to the water tank 11. The greatest feature of the gas amount measuring apparatus shown in FIG. 1 is that the change in the supply amount of the gas to be measured can be reflected in the change in the measurement value of the mass meter.

  In the apparatus of FIG. 1, when the measurement of the gas amount is started, the measured value of the electronic balance 2 at that time is set to the zero point, and thereafter, the relative mass with respect to the zero point is output. Thus, if the zero point setting operation is performed, the cumulative supply amount of gas at each time point can be known by dividing the measurement result of the electronic balance 2 by the density of water (mass per unit volume).

  In this case, if it is approximated that the volume of water pushed out from the graduated cylinder 4 is equal to the volume of gas discharged from the gas pipe 6 and the density of water is 1 [g / cc], the electronic balance In FIG. 2, the time-series data (mass data) of the numerical values output in the unit of [g] can be handled as they are as the cumulative supply amount of the gas expressed in the unit of [cc]. Furthermore, if the time series data (mass data) output from the electronic balance 2 is differentiated (differed) in the personal computer 1, the amount of gas generated in the gas source 7 at each time can also be known.

  However, the atmospheric pressure in the graduated cylinder 4 is different from the atmospheric pressure in the sample container 7b. That is, as shown in FIG. 1, when the liquid level of the graduated cylinder 4 is located above the liquid level of the water tank 3, the gas in the graduated cylinder 4 is depressurized (expanded) to a pressure lower than the atmospheric pressure. . On the other hand, although not shown, when the liquid level of the graduated cylinder 4 is located below the liquid level of the water tank 3, the gas in the graduated cylinder 4 is pressurized (compressed) to a pressure higher than the atmospheric pressure. . Thus, since the trapped gas is compressed or expanded from the atmospheric pressure in the graduated cylinder 4, strictly speaking, a volume of water equal to the volume of the gas discharged from the gas pipe 6 is present. It is not pushed out of the graduated cylinder 4. Therefore, correction calculation processing for correcting a measurement error of the gas amount caused by the gas being compressed or expanded in the graduated cylinder 4 may be performed on the mass data. Correction calculation and differentiation (difference) processing can be performed by the personal computer 1.

  In the apparatus of FIG. 1, the gas amount can be measured until the liquid level of the measuring cylinder 4 reaches the position of the opening 4a. In order to prevent the graduated cylinder 4 from being displaced upward due to the buoyancy of the gas collected in the graduated cylinder 4, the graduated cylinder 4 may be fixed to the support base 5 by a fixing means. Here, the fixing means is a concept including not only bolts and nuts but also gummed tape and the like.

  However, the maximum buoyancy that can act on the measuring cylinder 4 (the mass of water in the measuring cylinder 4 having a volume equal to the volume from the level of the opening 4 a of the measuring cylinder 4 to the level of the opening of the water tank 3) If the arrangement height of the graduated cylinder 4 with respect to the water tank 3 is determined so as to be less than the mass, the escalation of the graduated cylinder 4 can be avoided without using the fixing means.

  As described above, according to the gas amount measuring apparatus of the present embodiment, it is possible to reflect the change in the supply amount of the gas to be measured in the change in the measured value of the electronic balance 2. Since the change in the gas supply amount can be measured from the output of the electronic balance 2, it is possible to obtain a highly reliable measurement result as compared with the prior art that required reading the level of the liquid level visually. it can. In addition, the device can be configured using existing general-purpose graduated cylinders and beakers, and there is no need for electrodes, oscillators, etc., and wiring structures to connect them, which were necessary when measuring the amount of gas by capacitance. Therefore, an apparatus with a simple configuration can be realized.

  FIG. 2 shows a gas amount measuring apparatus according to another embodiment. This device includes a gas pipe 6 having one end connected to a gas source 7 and an airtight container 8 connected to the other end of the gas pipe 6 to collect gas discharged from the gas pipe 6. An airtight container 8 in which water is stored in advance, the gas from the gas pipe 6 is replaced with water and collected inside, and the replaced water is pushed outside, and a support base on which the airtight container 8 is placed 9 and a water pipe 10 that allows water in the airtight container 8 and water in the water tank 3 to flow. The point that the water tank 3 is mounted on the electronic balance 2 is the same as the apparatus of FIG.

  In short, this apparatus places an airtight container 8 in place of the graduated cylinder 4 of FIG. 1 on a support base 9, and when gas is introduced into the airtight container 8 through the gas pipe 6, the volume of the introduced gas. 1 is configured to be pushed out of the airtight container 8 into the water tank 3 through the water pipe 10, and the water replaced with the gas to be measured is pushed into the water tank 3 as in the apparatus of FIG. 1. Therefore, the amount of gas can be measured from the increasing tendency of the measurement result of the electronic balance 2.

  Moreover, since the airtight container 8 is arranged at a position higher than the water tank 3, it is possible to prevent a decrease in measurement accuracy due to the gas pressure in the airtight container 8 becoming too high. However, in this apparatus, it is necessary to make the connection part between the airtight container 8 and the gas pipe 6 and the water pipe 10 respectively as airtight structures 8a and 8b made of rubber plugs or the like, and the water pipe 10 is separately required. From the viewpoint of simplifying the device configuration and reducing the number of parts, the device of FIG. 1 is superior.

  FIG. 3 shows a gas amount measuring apparatus according to still another embodiment. In this apparatus, the support base 9 and the water tank 3 are omitted in the apparatus of FIG. 2, and the airtight container 8 is directly mounted on the electronic balance 2. Unlike the apparatus of FIGS. Is obtained from the decreasing tendency of the measurement result of the electronic balance 2. Since the water tank 3 is unnecessary, there is an advantage that the number of parts can be reduced. However, as in the case of the apparatus of FIG. 2, it is necessary that the connection portion between the airtight container 8 and the gas pipe 6 and the water pipe 10 be the airtight structures 8a and 8b. The device of 1 is superior.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this. In short, the present invention basically includes a gas source for supplying gas and a liquid previously stored therein, and replacing the gas supplied from the gas source with the liquid and collecting the liquid inside, while pushing the replaced liquid to the outside. In the gas measurement method using a gas collection container, the mass of the liquid pushed out from the gas collection container can be observed, and the change in the amount of gas supplied from the gas source is grasped based on the observation result The arrangement relationship between the gas collection container and the mass meter is not particularly limited to the relationship shown in FIGS.

  In each of the above embodiments, water is used as a liquid to be substituted for the gas to be measured in order to collect the gas to be measured. However, the gas and the liquid to be measured are either insoluble or difficult to dissolve in the liquid. There is no particular limitation as long as there is a relationship. When water is used as the liquid, carbon dioxide gas, hydrogen gas, oxygen gas, or the like can be measured. When the measurement object is methane gas, it is preferable to use saturated saline as the liquid. Mercury can also be used as the liquid.

  In each of the above embodiments, the electronic balance as a mass meter outputs the measurement result as digital data (mass data) to a personal computer, but the computer is not necessarily essential. In the mass meter, the measurement result may be displayed and output, and the display output may be read and recorded by the measurer. Even in this case, the reliability of the measurement result can be improved as compared with the conventional case where the operation of checking the position of the liquid level of the measuring cylinder with the position of the scale is required.

  In addition, temperature data representing the temperature of the sample 7a may be output from the temperature regulator 7c to the computer 1 so that the computer 1 can observe the change in the gas amount in association with the temperature. It will be apparent to those skilled in the art that other various design changes and combinations are possible.

1 is a schematic view of a gas amount measuring device according to an embodiment of the present invention. Schematic of the gas amount measuring apparatus by other embodiment of this invention. Schematic of the gas amount measuring apparatus by further another embodiment of this invention. Schematic which shows the principal part of the conventional gas amount measuring apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Personal computer (computer), 2 ... Electronic balance (mass meter), 3 ... Water tank (liquid tank), 4 ... Measuring cylinder (gas collection container), 4a ... Opening, 5 ... Support stand, 5a, 5b ... Beam , 6 ... gas pipe, 7 ... gas source, 7a ... sample, 7b ... sample container, 7c ... temperature regulator, 8 ... airtight container (gas collection container), 8a, 8b ... airtight structure, 9 ... support base, 10 ... water pipe, 11 ... water tank, 12 ... graduated cylinder, 12a ... opening, 13 ... gas pipe

Claims (4)

A gas collection container in which a liquid is previously stored;
A gas pipe for supplying gas into the gas collection container, and with the supply of gas from the gas pipe, the supplied gas is replaced with the liquid in the gas collection container. In the gas amount measuring device configured to push the liquid out of the gas collection container,
A gas amount measuring apparatus comprising a mass meter for measuring the mass of the liquid pushed out from the gas collection container. A liquid tank placed on the mass meter;
A support for supporting the gas collection container so that when the liquid is pushed out from the gas collection container into the liquid tank, the mass applied to the mass meter is increased by the mass of the pushed-out liquid; The gas amount measuring device according to claim 1, further comprising:   The gas amount measuring device according to claim 1 or 2, wherein the mass meter outputs the measurement result as mass data that can be acquired by a computer in real time.   A gas source for supplying a gas and a gas trap that previously stores the liquid and replaces the gas supplied from the gas source with the liquid and collects the liquid while pushing the replaced liquid to the outside. In the gas amount measuring method using a container, the mass of the liquid pushed out from the gas collection container is observed, and the change in the amount of gas supplied from the gas source is obtained based on the observation result. A characteristic gas amount measuring method.

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