JPH0361846A - Alcohol concentration detector - Google Patents

Abstract

PURPOSE:To blow air into a specimen stably and to make it possible to measure the concentration of alcohol from the specimen directly and continuously by blowing the air into the specimen through an inner tube having a branching part provided with an opening regulating valve, and measuring the concentration of the alcohol in the air rising up as bubbles. CONSTITUTION:Air is blown into a specimen 30 containing alcohol through an inner tube 20 having a branching part 24 provided with a blowing regulating valve 25 stably with a air blowing pump 21. The sample 30 is surrounded with an outer tube 10. The air containing alcohol rises up in the form of bubbles from the specimen 30. The air reaches a sensor 40. Thus, the concentration of the alcohol contained in the specimen can be detected directly, continuously and accurately.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to an alcohol concentration detection device, and more particularly, to detecting alcohol, such as ethyl alcohol, along with fine impurities.
The present invention relates to an apparatus for measuring the alcohol concentration in a sample containing isopropyl alcohol, etc., and is particularly suitable for measuring the alcohol concentration in a dye solution used during printing. [Prior Art] Conventionally, alcohol concentration has been detected in the manufacturing process of sake and mirin, or in a dye solution used for offset printing or the like. Such conventional detection of alcohol concentration generally involved pumping out a sample containing alcohol and detecting the alcohol concentration based on the specific gravity of the aqueous solution. However, with conventional detection methods, it is necessary to pump out a sample containing alcohol each time detection is performed, which is extremely troublesome. Therefore, as shown in Figure 4, sample l containing alcohol
A means is provided for measuring the alcohol concentration in the sample l by covering the box body 3 provided with the pipe 2 and measuring the alcohol concentration evaporated in the box body 3 with a gas sensor 6 provided on the box body 3. It came to be. However, in such a measurement, air is introduced into the box 3 from one pipe 2, and the air inside the box 3 is discharged from the other pipe 2, so that alcohol does not enter the box 3. The alcohol concentration in the sample containing alcohol was measured by measuring the alcohol concentration in the box 3 after a certain period of time had elapsed. Therefore, continuous measurement of alcohol concentration has not yet been possible. At the same time, since the alcohol vapor pressure depends on the temperature of the sample 1, it has been impossible to directly detect the alcohol concentration in the sample 1 containing alcohol based on the concentration of evaporated alcohol. Therefore, it is possible to measure the alcohol concentration of an aqueous solution containing alcohol by continuously detecting the alcohol concentration that evaporates from the alcohol-containing sample using a gas sensor, and by measuring the temperature of the alcohol-containing sample and performing temperature correction. It has come to be carried out. As shown in Fig. 5, such measurement means include:
A gas sensor 6 is installed in a part of the air pipe 5 connected to the ventilation pump 4.
is installed in the ventilation pipe 5 on the ventilation side of the gas sensor 6,
A gas sampling tube 7 formed by a gas-liquid separation membrane is placed in the sample l containing alcohol, and a temperature sensor 8 is placed in the sample 1, and the sample temperature output from the temperature sensor 8 causes the gas sensor 6 to There was a measuring means configured to give a temperature correction to the alcohol concentration output from the alcohol concentration output and output it as a final output. [Problems to be Solved by the Invention] However, although the conventional means described above are suitable for measuring the concentration of alcohol that does not contain many impurities, such as drinking alcohol, When attempting to measure the alcohol concentration in a sample where insoluble matter such as ink scum or H solution for pH adjustment is present in water and alcohol, these insoluble matter clog the gas-liquid separation membrane, causing the experiment to be interrupted. According to the results, after about 40 days of use, the measured value decreased by about 10% even at the same alcohol concentration. Therefore, the present invention provides direct measurement from the sample and continuous measurement even when insoluble matter is present by blowing air into a sample containing alcohol and measuring the alcohol concentration in the air that rises as bubbles. It is an object of the present invention to provide an alcohol concentration detection device that enables measurement and, in particular, allows stable blowing of air into a sample. Means for Solving Problem F] In order to achieve the above-mentioned object, the present invention comprises an outer cylinder, an inner cylinder as an air supply pipe located inside the outer cylinder, and an outer water-filled inner cylinder. The gas sensor is placed in a sample containing alcohol, and the air bubbles that blow out from the inner cylinder into the sample are captured inside the outer cylinder, and the gas sensor measures the alcohol concentration in the air. The present invention is characterized in that air is blown into the inner cylinder from a blower pump that sends air through a blow-off adjustment valve, and the air can be discharged from a branched portion through an opening adjustment valve.

[Effect]

In the alcohol concentration detection device according to the present invention, the outer cylinder is placed in an aqueous solution containing alcohol as a sample. Then, the inner cylinder inside this outer cylinder will also be located in the specimen. Thereafter, by sending air into the inner cylinder located within the sample, the air sent into the inner cylinder is blown out into the sample. This air then becomes bubbles and rises up the outer cylinder, and is eventually released into the atmosphere while the alcohol concentration is measured by a gas sensor. When blowing air into the inner cylinder like this. In the present invention, air is blown into the inner cylinder from a blower pump that sends air into the inner cylinder through a blow-off adjustment valve, and the branch part is configured to allow air to be released through an open adjustment valve. be. Therefore, there is no need to suddenly throttle the air supplied from the blower pump with a blow-out regulating valve to maintain a predetermined amount of air.
Not only does the blow-out regulating valve not become clogged, but there is no load placed on the blower pump. [Example] An example of the present invention will be described below according to an illustrated example. FIG. 1 is a schematic diagram showing an apparatus according to the invention. In the figure, the alcohol concentration detection device according to the present invention is
An outer cylinder 10, an inner cylinder 20 as an air pipe located inside the outer cylinder 10, and a sample 30 containing alcohol by placing the outer cylinder 10 and the inner cylinder 20 in a sample 30 containing alcohol.
It is formed from a gas sensor 40 that captures air that is blown into the air and becomes bubbles inside the outer cylinder 10 and measures the alcohol concentration in the air. The outer cylinder 10 is used to capture air bubbles containing alcohol vapor blown into the specimen 30 from the inner cylinder 20, and is used by being inserted into the specimen 30. In addition to the inner cylinder 20, a temperature sensor 50 is located inside the outer cylinder 10. Moreover, the temperature sensor 50 can be used regardless of whether a semiconductor is used as long as it can detect the temperature of the aqueous solution containing alcohol, which is the sample 30. The inner cylinder 20 is used to adjust the flow rate of air from the blower pump 21 to an appropriate flow rate using a blow-off adjustment valve 22 and blow it out into the specimen 30, and the air outlet 23 at its tip is located within the cylinder of the outer cylinder 10. It is long enough to Also, the air from the blower pump 21 is divided into two types: air that is sent into the inner cylinder 20 via the blowout adjustment valve 22 by the first branch portion 24, and air that is sent to the open port via the opening adjustment valve 25 and released into the air. Furthermore, the material of the outer cylinder 10 and the inner cylinder 20 is required to be rust-resistant and not deteriorated by alcohol. It is for measuring the alcohol concentration inside the outer cylinder 10, and is located between the capture port 41 opened inside the outer cylinder 10 and the outlet port 42 communicating with the outside. Further, a coarse filter 43, for example, an open-cell sponge, is positioned between the capture port 41 and the gas sensor 40. Furthermore, the gas sensor 40 used here not only has an explosion-proof structure covered with a double wire mesh to measure the alcohol concentration, but also has a fine porous membrane between the inner wire mesh 44 and the outer wire mesh 45. 46 is the arrangement. Specifically, as the gas sensor 40, a catalytic combustion gas sensor 40, a semiconductor gas sensor 40, or the like is used. Next, the operation of the alcohol concentration detection device according to the present invention will be explained. First, the outer cylinder 1O is inserted into the specimen 30, and at this time, the inner cylinder 20 in the outer cylinder 10 and the temperature sensor 50 are also positioned in the specimen 30 at the same time. Thereafter, air is blown into the inner cylinder 20 from the blower pump 21. At this time, the air sent from the blower pump 21 is blown into the specimen 30 from the air outlet 23 via the air outlet 23 through the air outlet 23 by the required flow rate by adjusting the air outlet adjustment valve 22 and the open adjustment valve 25. Air is open adjustment valve 2
5 directly into the air. Then, this air is blown out from the outlet 23 of the inner cylinder 20 into the specimen 30, and the blown air turns into bubbles and rises inside the outer cylinder 10. At this time, alcohol that has evaporated from the surface of the specimen 30 in the outer cylinder 10 is present in the outer cylinder 10, and alcohol dissolved in the bubbles rising inside the specimen 30 is also present in the outer cylinder 10.
It will rise between 0 and 0. The alcohol-containing air rising in the outer cylinder lO in this manner reaches the gas sensor 40 via the filter 43. Here, the air sent out from the inner cylinder 20 into the specimen 30 is
It becomes a bubble and rises inside the specimen 30 corresponding to the inside of the cylinder of the outer cylinder lO, and when it eventually reaches the upper surface of the specimen 30, the bubble bursts and is located inside the outer cylinder lO, and reaches the gas sensor 40 via the filter 43. That will happen. Therefore, the air immediately after the bubble bursts becomes a pulsating flow due to bubbling caused by the bursting of the bubble, but when the air reaches the gas sensor 40, this pulsating flow is suppressed by the filter 43. This means that it can be measured as a laminar flow. In this way, the alcohol concentration in the rising gas is measured by the gas sensor 40, while the temperature sensor 50 outputs the temperature information of the sample 30 in the outer cylinder 10. The gas sensor 40 that has previously measured the temperature information
A search section (not shown) searches the output table from the gas sensor 40, and a comparing section (not shown) compares the results with the output from the gas sensor 40, and outputs the alcohol concentration of the sample 30 to an output section (not shown). Note that instead of taking such a means, it is also possible to obtain coefficients corresponding to each temperature in advance, perform a certain calculation based on the measurement result by the temperature sensor 50, and output the result to the output section. Note that the output here can be configured to simply display a numerical value, or to issue an alarm when the concentration exceeds a preset constant range. Alternatively, it is also possible to issue an instruction to add alcohol. The alcohol concentration detection device according to this embodiment can be used stably for a long period of time because even if insoluble matter is present in the sample 30, there is no part that will malfunction due to the insoluble matter. In addition, compared to simply measuring the alcohol concentration using evaporated alcohol from the surface of the specimen 30, alcohol dissolved in air bubbles can also be used for measurement, so even if the diameter of the outer cylinder 10 is small, sufficient continuous measurement can be performed. It is. Furthermore, since the outer tube 10 is inserted into the specimen 30, measurement errors do not occur due to the flow of the specimen 30, etc. In this embodiment, the air from the blower pump 21 is divided into air that is sent into the inner cylinder 20 via the blowout regulating valve 22 by the branch section 24, and air that is sent to the open port via the open regulating valve 25 and released into the air. It is divided into air and air. This means that the total amount of air blown from the air blowing pump 21 is controlled by the blowing adjustment valve 22.
If you try to squeeze the air with a chisel and send it out to the inner cylinder 20, the orifice of the blow-out adjustment valve 22 will have to be narrowed down considerably, and it will get clogged with dirt. This is to prevent the blow-out regulating valve 22 from clogging by opening it. Specifically, when using an air blowing pump 21 with a performance of 1,517 min, and sending the air into the specimen 30 with the air volume reduced to 0.5 AC/min, the same adjustment is made as shown in No. 21il. When the valve was used alone, it was measured that the air flow rate decreased by about 20% after 5 days of use, but when the open adjustment valve 25 was provided in addition to the blow-off adjustment valve 22 as in the example, the amount decreased by 20%. There was almost no decrease in air flow rate even after daily use, and the device could be used without maintenance for 2 to 3 months. Furthermore, with this embodiment, the amount of air blown from the air pump 21 is not extremely restricted, so there is no burden on the air pump 21, and the service life of the air pump 21 can be extended. . Further, in this embodiment, a capture port 41 provided inside the outer cylinder 10
and the gas sensor 40-, a coarse filter 43,
For example, since an open-cell sponge is positioned, the air flow becomes a pulsating flow due to bubbling caused by the bursting of air bubbles, but before it reaches the gas sensor 40, this pulsating flow is suppressed by the filter 43 and can be measured as a laminar flow. becomes. Therefore, if the flow remains pulsating, the alcohol concentration will be measured non-uniformly, but since the flow at the time of measurement is laminar, the concentration can always be measured as a uniform concentration. Further, the filter 43 used here is preferably a filter 43 having a porosity of about 20 to 80%, although it is sufficient if the pulsating flow can be suppressed. Furthermore, in this embodiment, the gas sensor 40 not only has an explosion-proof structure covered with a double wire mesh to measure the alcohol concentration, but also has a fine porous material 1146 between the inner wire mesh 44 and the outer wire mesh 45. It is an impressive arrangement. Therefore, even if water splashes onto the gas sensor 40 for some reason, this porous! I46 prevents water from entering the interior, and the porous membrane 46 used here allows air containing alcohol to pass through.
It is sufficient if it can prevent the passage of water, but 0.
The porosity is about 5 to 5 ILm, and the gas sensor 40
It is desirable to use a porous membrane 46 made of a material with excellent heat resistance, such as Teflon resin, since it is heated. Furthermore, in this embodiment, a temperature sensor 50 for temperature compensation is located inside the outer cylinder IO. This temperature sensor 50 can be installed outside the outer cylinder 10, but since bubbles burst inside the outer cylinder 10 and the temperature decreases due to the heat of vaporization accompanying the bursting, the temperature sensor 50 can be installed outside the outer cylinder 10, which is the place where the actual measurement is performed. lO
It is preferable to measure the temperature of the specimen 30 inside the outer cylinder 10 using the temperature sensor 50. According to actual measurements, the temperature of the specimen 30 inside the outer cylinder 10 is about 1 to 2 times higher than that of the specimen 30 outside the outer cylinder 10. It was measured that the temperature was low. Furthermore, if the temperature of the specimen 30 and the temperature of the air blown from the air pump 21 are different, water droplets may adhere to the air pipe or the outer cylinder 10, and the alcohol dissolved in these water droplets may make it impossible to measure the alcohol concentration correctly. Since the temperature of the specimen 30 is measured by the temperature sensor 50, the above-mentioned adverse effects do not occur by maintaining the air blowing at the measured temperature. The graph shown in FIG. 3 compares the changes in characteristics over time between the alcohol concentration detection device according to the present invention and the conventional alcohol concentration detection device shown in FIG. The results of this experiment were conducted under the following conditions: Sample 30 temperature: 15±℃ Sample 30 pH: 5-7. 0: Alcohol concentration detection device according to the present invention Port: Shown as a conventional alcohol concentration detection device. This graph shows that the characteristics of conventional alcohol concentration detection devices decrease by approximately 10% over the course of 4 days;
It can be seen that the alcohol concentration detection device according to the present invention can be used stably for a long period of time, with the detection results hardly changing over time. In the above description, ethyl alcohol and inpropyl alcohol were used as examples of the alcohol in the sample 30, but it goes without saying that other alcohols can also be used. [Effects of the Invention] As explained above, the present invention detects the presence of insoluble matter by blowing air into a sample containing alcohol and measuring the alcohol concentration in the air that rises in the form of bubbles. This makes it possible to perform direct and continuous measurements from the specimen, and in particular, to stably blow air into the specimen.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an alcohol concentration detection device according to the present invention, FIG. 2 is a graph showing the temporal characteristics when a blower pump is provided with a blow-off adjustment valve and an open adjustment valve, and FIG.
The figure is a graph showing changes over time in the characteristics of the alcohol concentration detection device according to the present invention in comparison with a conventional alcohol concentration detection device. Figures 4 and 5 show conventionally proposed alcohol filtration detection devices. It is a schematic diagram.

Claims (1)

[Scope of Claims] 1. An outer cylinder, an inner cylinder as an air pipe located inside the outer cylinder, and an outer cylinder and an inner cylinder placed in a sample containing alcohol, and a sample from the inner cylinder. It is formed by a gas sensor that captures the air that blows out and becomes bubbles inside the outer cylinder, and measures the alcohol concentration in the air.A blower pump sends air into the inner cylinder, and a blow-off adjustment valve is installed in the inner cylinder. 1. An alcohol concentration detection device characterized by being formed so that air can be blown through the alcohol concentration detection device, and air can be released from the branch portion through an opening adjustment valve.