JPH0452682Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a method for measuring the concentration of volatile components in an aqueous solution that can measure the concentration of volatile components in an aqueous solution containing volatile components such as ethyl alcohol. Concerning a concentration measuring device, specifically, a gas sensor is disposed within the device main body, and volatile components in the liquid are permeated into the device main body through a gas permeable partition provided on a part or all of the outer wall of the device main body, and A device for measuring the concentration of volatile components in an aqueous solution, which allows a carrier gas to flow into the device body to mix volatile components with the carrier gas, and then leads the mixed gas to a gas sensor to measure the concentration of the volatile components. Regarding.

[Conventional technology]

Conventionally, as such a measuring device, for example,
The one disclosed in Japanese Patent No. 58-139054 has been proposed. In this configuration, a block member with a carrier gas flow groove formed on its lower surface is placed in the lower part of the main body of the device in contact with a gas permeable partition, and when the carrier gas sent through the inlet passage passes through the flow groove, This device is configured to guide the volatile components that have passed through the gas permeable partition wall together with the carrier gas into the sensor chamber, but as mentioned above, it is necessary to place a block member with a complicated structure at the bottom of the device main body, resulting in high costs. There are drawbacks to it.

Therefore, as disclosed in, for example, Japanese Utility Model Application Publication No. 61-206860, it has been proposed to use a cylindrical member with a relatively simple structure in place of the block member. The structure of this device is that an inner cylinder is placed inside a bottomed cylindrical device main body, and an inflow path and an outflow path for carrier gas are formed between the device main body and the inner cylinder and within the inner cylinder. A flow path is formed between the gas permeable partition provided at the bottom and the lower end of the inner cylinder, and when the carrier gas sent from between the device main body and the inner cylinder passes through the flow path on the upper surface of the gas permeable partition, The carrier gas and the volatile components are mixed in this part, and the mixed gas is then guided to the gas sensor side through the outflow path in the inner cylinder for measurement.

[Problem that the invention attempts to solve]

However, according to the above configuration, when gas flows from the outer inflow channel to the inner outlet channel through the upper surface of the gas permeable partition, the gas flows from the outer inflow channel directly across the lower end of the inner cylinder to the inner outlet channel. Some gases flow from the outside inflow path through the upper surface of the gas permeable partition wall to the outflow path, which tends to cause variations in the concentration of the mixed gas introduced to the sensor. Although the aqueous solution has the same concentration, the measurement results may vary, resulting in poor reproducibility. Moreover, in the above structure, if the inner cylinder is configured to have a long dimension as shown in the above publication in order to improve the gas mixability, the gas flow passing through the inner cylinder is It takes longer and becomes less responsive,
In addition, volatile components may condense on the inner surface of the inner cylinder, which may cause errors in measurement results.

The present invention was developed in view of the above-mentioned circumstances, and is a device for measuring the concentration of volatile components in an aqueous solution, which has a simple structure, is inexpensive, has good reproducibility, and has excellent responsiveness and reliability. The purpose is to provide

[Means for solving problems]

That is, the characteristic configuration of the present invention is that a gas mixing chamber into which the carrier gas is sent via an inflow path and a sensor chamber into which the gas in the gas mixing chamber is sent through an outflow path are formed in the device main body, and the gas A device for measuring the concentration of volatile components in an aqueous solution, wherein a gas permeable partition wall exposed to the outside of the device body is provided on the wall of the mixing chamber, and a gas sensor for detecting the concentration of the volatile component is arranged in the sensor chamber. The effective cross-sectional area of the gas mixing chamber is larger than the effective cross-sectional area of each of the inlet and outlet channels, and its functions and effects are as follows.

[Effect]

When the volatile component vapor that has passed through the gas permeable partition wall and flowed into the gas mixing chamber and the carrier gas that has flowed into the gas mixing chamber from the inflow path are mixed in the gas mixing chamber, as in the above configuration, Since the effective flow cross-sectional area of the gas mixing chamber is larger than the effective flow cross-sectional area of each of the inflow and outflow channels, the carrier gas that flows from the inflow channel does not directly flow to the outflow channel, and the capacity is reduced. When the mixed gas is mixed with the gas filling the large gas mixing chamber and flows out to the outlet side where the effective flow cross-sectional area is small, the flow is obstructed by the side wall of the gas mixing chamber on the outlet side. This causes turbulence, resulting in mixing in the gas mixing chamber, and only well-mixed gases are supplied to the sensor chamber via the outlet.

In addition, the concentration of the mixed gas in the sensor chamber is influenced by, in addition to the concentration of the aqueous solution, for example, the water temperature, the flow rate of the carrier gas, and the pressure difference between the inside and outside of the gas permeable partition. Since the cross-sectional area is large, even if each of the above factors fluctuates slightly, the gas mixing chamber can absorb the variation in each factor, and the sensor output can be stabilized.

[Effect of idea]

As a result, the sensor output can be stabilized and the reproducibility can be improved, and there is no need to form a long outflow path.As shown in the example below, the gas mixing chamber and the sensor chamber can be connected through a partition wall. This has the effect of providing a highly reliable concentration measuring device that can be placed in close proximity, has good responsiveness, and does not cause condensation of volatile components. Moreover,
There is no need to provide a block member or inner cylinder with a complicated structure as in the past, and it is only necessary to place a plate-shaped partition inside the main body of the device, so manufacturing costs can be reduced.
It also has the effect of extending the measurement life.

[Example 1] Hereinafter, an example of the present invention will be described based on the drawings.

As shown in FIG. 1, a gas permeable partition wall 6 made of a sintered polyethylene body is disposed at the lower end opening of a cylindrical device main body 1, and an O-ring 1
The upper end of the apparatus body 1 is open to the atmosphere. A partition wall 2 is attached to the lower part of the device main body 1 with a gap between the gas permeable partition wall 6 and the device main body 1.
A gas mixing chamber 3 is formed between the peripheral side wall of the gas permeable partition wall 6 and the partition wall 2 . A substrate 9 of a sensor 4 is attached to the device main body 1 at an interval above the gas mixing chamber 3, and is connected between the peripheral side wall of the device main body 1, the sensor substrate 9, and the partition wall 2. A sensor chamber 5 is formed in which the sensor 4 is housed.

An inflow pipe 7a through which a carrier gas such as air is sent into the mixing chamber 3 is disposed within the device main body 1, and the tip of the inflow pipe 7a connects to a hole 12 formed in the sensor substrate 9 and the partition wall 2. 13 and is disposed within the mixing chamber 3. The other end of the inflow pipe 7a is connected to a pump (not shown) to stably feed the carrier gas into the gas mixing chamber 3 at a constant flow rate. Further, the partition wall 2 is provided with an outlet passage 8 for sending gas from the mixing chamber 3 to the sensor chamber 5, and the sensor board 9 is provided with an outlet 14 for discharging gas to the outside of the device main body 1. has been done. The effective flow path cross-sectional area of the gas mixing chamber 3, that is, the cross-sectional area of the flow path of the gas moving within the gas mixing chamber 3 is the inflow path 7 of the inflow pipe 7a.
and the effective flow channel cross-sectional area of the outflow channel 8.

The gas-permeable partition wall 6 is water-repellent and porous, and water cannot pass through the gas-permeable partition wall 6, but volatile components dissolved or dispersed in water are mixed with gaseous molecules. It is something that can be penetrated.

Next, a method of operating the concentration measuring device A configured as described above when measuring the alcohol concentration in the brewing tank 18 of beer, whiskey, sake, etc. containing ethyl alcohol as a volatile component will be described.

Reference numeral 19 in FIG. 2 is an auxiliary tank, and the auxiliary tank 19 is connected to the brewing tank 18 through a supply pipe 16 equipped with a circulation pump 15 and a return pipe 17.
It is designed to circulate between 9 and 9. The lower part of the concentration measuring device A having the above structure is immersed in this auxiliary tank 19.

When the gas permeable partition wall 6 is brought into contact with an alcohol aqueous solution, the alcohol gas permeates through the gas permeable partition wall 6 due to the action of the gas permeable partition wall 6 and flows into the mixing chamber 3.
Come inside. Then, this alcohol gas is mixed with the carrier gas sent from the inflow pipe 7a to the mixing chamber 3, and is sent by the carrier gas to the sensor chamber 5 through the outflow path 8, and is detected by the gas sensor 4 in the mixed gas. of alcohol gas is detected, and the alcohol concentration contained in the alcohol aqueous solution can be measured. That is, in an equilibrium state where alcohol gas passes through the gas permeable partition wall 6 and enters the gas mixing chamber 3, while the carrier gas flows into the gas mixing chamber 3, the alcohol gas concentration in the mixed gas and the alcohol concentration in the aqueous solution are Since there is a proportional relationship, by guiding the alcohol gas in the mixed gas to the sensor chamber 5 and measuring it, the alcohol concentration in the aqueous solution can be measured continuously in a short time.

The sensor chamber 5 is surrounded by the peripheral wall of the device main body 1, the substrate 9 on which the sensor 4 is attached, and the partition wall 2, and the sensor chamber 4 is surrounded by the gas mixing chamber 3. Since the chamber is filled with the mixed gas sent from the mixing chamber 3, it is not affected by external air and more stable concentration measurement can be performed, and the mixed gas is sent directly from the mixing chamber 3 to the sensor chamber 4. It has good responsiveness and does not cause condensation. Furthermore, the gas sensor 4 is composed of a catalytic combustion type gas sensor, and since its output is approximately proportional to an increase in alcohol gas concentration, it also has the advantage of being able to accurately measure the concentration regardless of increases or decreases in the alcohol concentration in the aqueous solution. In addition, according to the above configuration, the gas permeable partition wall 6
The structure allows the carrier gas to come into contact with the carrier gas over a wide area, making it possible to detect highly sensitive alcohol solutions even at low concentrations.

Note that 20 in the figure is a thermistor for measuring the external liquid temperature and correcting the sensor output value, and is fitted into an opening 21 formed in the side wall of the device main body 1 with good sealing performance. A lead wire 22 is attached to the sensor board 9. Therefore,
There is no need to specially attach a mounting plate for the thermistor to the device body 1, and the structure of the device body 1 is simplified.
In addition, it can be made smaller, and the thermistor 2
The sensor 4 can be attached to the device body 1 at the same time as the sensor 4 is installed, improving productivity and reducing costs.

Furthermore, various materials can be used for the gas permeable partition wall 6 as long as they are water repellent and porous, such as polyethylene,
A porous material such as polypropylene, silicone resin, or fluorine resin, a sintered porous body of polypropylene, a porous body such as silicone resin, or fluororesin, or a hollow porous body can be used. Further, the volatile components include, in addition to gaseous components present in the liquid, liquid components dissolved or dispersed in the liquid, and are introduced into the mixing chamber 3 in a gaseous state through the gas permeable partition wall 6. It is transparent. Therefore,
In addition to the above-mentioned alcohols, the volatile components can include, for example, organic materials such as ketones, ethers, and aromatic hydrocarbons, and inorganic components such as hydrogen sulfide, carbon dioxide, and chlorine. moreover,
The type of gas sensor 4 is not limited in any way, and for example, a semiconductor gas sensor can also be used.

[Example 2] As shown in FIG. 3, in the gas mixing chamber 3,
For example, mixing of volatile components and carrier gas may be promoted by filling a mixing promoting member such as glass fibers 23 or glass beads to improve gas dispersibility.

[Embodiment 3] As shown in FIG. 4, adjustment chambers 24, 24 are provided between the gas mixing chamber 3 and the sensor chamber 5 via separation walls 25, 25, and the mixed gas flowing out from the outflow path 8 is The mixed gas may be further mixed in the adjustment chamber 24.

[Embodiment 4] As shown in FIG. 5, the sensor substrate 9 may also be used as the partition wall 2, which has the advantage of reducing the number of component parts.

[Embodiment 5] As shown in FIG. 6, the tip of the inflow pipe 7a may be formed into a trumped shape to protrude into the gas mixing chamber 3, and the carrier gas is diffused to the circumferential side and mixed with volatile components. It has the advantage of improving the mixability of

[Example 6] As shown in FIG. 7, the tip of the inflow pipe 7a may be closed and a large number of small holes may be bored at the tip of the inflow pipe 7a, similar to the above Example 5. There are advantages.

Note that although reference numerals are written in the claims section of the utility model registration for convenience of comparison with the drawings, the present invention is not limited to the structure of the attached drawings by such entry.

[Brief explanation of the drawing]

The drawings show an embodiment of the device for measuring the concentration of volatile components in an aqueous solution according to the present invention, FIG. 1 is a sectional view of the main part of the concentration measuring device, FIG. 2 is a schematic diagram showing the measuring method, and FIG. 3 7 to 7 are sectional views of main parts of concentration measuring devices of different embodiments, respectively. DESCRIPTION OF SYMBOLS 1... Apparatus body, 2... Partition wall, 3... Gas mixing chamber, 4... Gas sensor, 5... Sensor chamber, 6...
Gas permeable partition wall, 7...Inflow path, 8...Inflow path, 9
...Sensor board, A...Concentration measuring device.

Claims (1)

[Claims for Utility Model Registration] 1. A gas mixing chamber 3 into which a carrier gas is sent via an inflow path 7, and a sensor chamber 5 into which gas in the gas mixing chamber 3 is sent through an outflow path 8 are connected to an apparatus main body 1. A gas permeable partition wall 6 is formed on the wall of the gas mixing chamber 3 and is exposed to the outside of the apparatus main body 1, and a gas sensor 4 for detecting the concentration of volatile components is arranged in the sensor chamber 5. A device for measuring the concentration of volatile components in an aqueous solution,
An apparatus for measuring the concentration of volatile components in an aqueous solution, wherein the effective flow cross-sectional area of the gas mixing chamber 3 is larger than the effective flow cross-sectional area of each of the inflow passage 7 and the outflow passage 8. 2 The device main body 1 is formed into a cylindrical shape with a bottom, the gas permeable partition wall 6 is disposed at the bottom of the device main body 1, and the gas mixing chamber 3 is connected to the peripheral side wall of the device main body 1 and the gas permeable partition wall 6 is disposed at the bottom of the device main body 1. The device for measuring the concentration of a volatile component in an aqueous solution according to claim 1, which is surrounded by a partition wall 6 and a partition wall 2 disposed within the main body 1 of the device. 3. Utility model registration claim 2, wherein the sensor chamber 5 is surrounded by a peripheral side wall of the device main body 1, a substrate 9 on which the gas sensor 4 is attached, and the partition wall 2. An apparatus for measuring the concentration of a volatile component in an aqueous solution as described in 2. 4. The device for measuring the concentration of volatile components in an aqueous solution according to any one of claims 1 to 3, wherein the gas permeable partition wall 6 is formed of a water-repellent porous material. 5 Utility model registration claims 1 to 4, wherein the gas sensor 4 is a catalytic combustion type gas sensor
2. A device for measuring the concentration of volatile components in an aqueous solution according to any one of the above items. 6. The device for measuring the concentration of a volatile component in an aqueous solution according to any one of claims 1 to 5, wherein the volatile component is ethyl alcohol.