JP2874269B2 - Alcohol concentration detector - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an apparatus for detecting an alcohol concentration, and more particularly, to measuring an alcohol concentration in a sample containing alcohol, for example, ethyl alcohol, isopropyl alcohol, etc., together with fine impurities. More particularly, the present invention relates to an alcohol concentration detecting device which is suitable for measuring the alcohol concentration in a squeezing solution used at the time of printing and which facilitates zero adjustment of a gas sensor.

[Prior Art] Conventionally, detection of an alcohol concentration in a liquor or mirin manufacturing process, or detection of an alcohol concentration in a shampoo used for offset printing or the like has been performed.

Such conventional detection of alcohol concentration is generally performed by extracting a sample containing alcohol,
The alcohol concentration was detected by the specific gravity of the aqueous solution.

However, if a conventional detection method is employed, it is necessary to pump out a sample containing alcohol every time detection is performed, which is extremely troublesome.

Therefore, as shown in FIG. 3, the sample 1 containing alcohol is covered with a box 3 provided with a pipe 2, and the concentration of the alcohol evaporated in the box 3 is measured by a gas sensor 6 provided on the box 3.
As a result, means for measuring the alcohol concentration in the sample 1 has been provided.

However, in such a measurement, the air is sent into the box 3 from one pipe 2 and the air in the box 3 is discharged from the other pipe 2 so that the alcohol is After a certain period of time, the alcohol concentration in the sample containing alcohol was measured by measuring the alcohol concentration in the box body 3 after a certain period of time.

Therefore, it was still impossible to measure the continuous concentration of alcohol.

At the same time, since the alcohol vapor pressure depends on the temperature of the sample 1, it is impossible to directly detect the alcohol concentration in the sample 1 containing the alcohol based on the concentration of the evaporated alcohol.

Therefore, by continuously detecting the concentration of alcohol evaporating from the sample containing alcohol with a gas sensor, and measuring the temperature of the sample containing alcohol and performing temperature correction, it is possible to measure the alcohol concentration of the aqueous solution containing alcohol. It has been done.

As such a measuring means, as shown in FIG. 4, a gas sensor 6 is provided in a part of a blower tube 5 connected to the blower pump 4, and the blower tube 5 on the blower side of the gas sensor 6 is provided.
Is provided with a gas sampling tube 7 formed by a gas-liquid separation membrane positioned in the sample 1 containing alcohol, a temperature sensor 8 is positioned in the sample 1, and the sample temperature output from the temperature sensor 8 There is a measuring unit formed so as to give a temperature correction to the alcohol concentration output from the gas sensor 6 and output the final output.

However, according to the conventional means as described above, alcohol which does not contain much impurities, such as alcohol for beverages, is suitable for measuring the concentration, but as in a squeezing solution used for printing, water and alcohol are used. When trying to measure the alcohol concentration in a sample in which insoluble matter such as ink residue or H solution for pH adjustment is present, these insoluble matter are clogged in the gas-liquid separation membrane. By use, even if the alcohol concentration is the same, the measured value is reduced by about 10%.

The same applicant has further provided an alcohol concentration detecting device as shown in FIG. 5 by Japanese Patent Application No. 63-267825.

This alcohol concentration detecting device has a measurement pipe 20 and a temperature sensor 30 which are located in a sample 10 containing alcohol.

Further, an air supply pipe 21 extending from above the measurement pipe 20 to slightly inside the lower end of the measurement pipe 20 is provided in the measurement pipe 20.
Is decorated. When the measurement pipe 20 is positioned in the sample 10 containing alcohol, the air supply pipe 21 is positioned in the sample 10 at the same time.

The measuring pipe 20 has a gas sensor
A gas sensor 23 is provided via a filter 22 as a protective material for 23. Further, around the filter 22, a blocking material 24 is provided.
Is provided, and the air that has risen inside the measurement pipe 20 is always discharged to the atmosphere via the gas sensor 23.

The air supply pipe 21 is provided with a blower pump 25 for sending air into the air supply pipe 21.

Further, in such an alcohol concentration measuring device, first, the measurement pipe 20 and the temperature sensor 30 are inserted into the sample 10. At this time, the air supply pipe 21 in the measurement pipe 20 is also positioned in the sample 10 at the same time.

Thereafter, air is blown from the blower pump 25 into the air blower pipe 21.

Then, this air is blown out from the lower end of the air supply pipe 21 into the sample 10, and the blown air turns into bubbles to form the measurement pipe 20.
It will rise inside.

At this time, in the measurement pipe 20, alcohol evaporated from the surface of the sample 10 in the measurement pipe 20 is present, and alcohol dissolved in bubbles rising in the sample 10 together rises in the measurement pipe 20. And the gas sensor 23.

Therefore, the alcohol concentration in the gas rising by the gas sensor 23 is measured.On the other hand, the temperature sensor 30 outputs the temperature information of the specimen 10, so that the temperature information based on the output temperature information is obtained. An output table from the gas sensor 23 that has been measured in advance is searched by a search unit (not shown), and the result is compared with the output from the gas sensor 23 by a comparison unit (not shown), and the alcohol concentration of the sample 10 is output by an output unit (not shown). Is output to

Therefore, in such an alcohol concentration detection device, the alcohol concentration is corrected by the temperature output from the temperature sensor 30, and even when insoluble matter is present in the sample 10 containing alcohol, the alcohol concentration is directly detected from the sample 10. It enables measurement and continuous measurement.

[Problems to be Solved by the Invention] However, since the gas sensor used in such an alcohol concentration measuring apparatus is deviated due to environmental conditions or changes over time, it is usually used while adjusting the zero point at appropriate intervals. It was needed to be.

In consideration of such zero point adjustment, in the alcohol concentration measuring apparatus as shown in FIG. 5, the measuring pipe and the temperature sensor are usually put in water before starting the use or during the use, and contain no alcohol. A complicated operation of adjusting the zero point by measuring air with a gas sensor has been required.

Therefore, the present invention improves the alcohol concentration measuring device shown in FIG. 5 so that the zero point can be adjusted while the measuring pipe and the temperature sensor are positioned in the sample, and the characteristics of the gas sensor are kept constant. It is an object of the present invention to provide an alcohol concentration measuring device that maintains the above-mentioned value and eliminates a complicated operation for zero point adjustment.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides a measuring pipe and a temperature sensor which are positioned in a sample containing alcohol, and the measuring pipe is provided with the measuring pipe. When placed inside, the air tube located in the sample at the same time,
A cleaning pipe that sends air to a position that does not reach the sample when the measurement pipe is placed in the sample is installed, and the gas sent from the air supply pipe returns to the measurement pipe through the sample in the gas. A gas sensor for measuring the alcohol concentration is provided.

[Operation] In the alcohol concentration detection device according to the present invention, the measurement pipe and the temperature sensor are placed in an aqueous solution containing alcohol as a sample, and the air supply pipe in the measurement pipe is also positioned in the sample.

Thereafter, by sending air into an air supply pipe located in the sample, the air sent into the air supply pipe is blown into the sample.

Then this air becomes bubbles and rises in the measuring pipe,
Eventually, the alcohol concentration is measured by the gas sensor and released into the atmosphere.

Further, the alcohol concentration measured in this way is corrected under the temperature condition measured by the temperature sensor to obtain the alcohol concentration in the sample.

Furthermore, in this alcohol concentration measurement device, when the air supply to the air supply pipe is stopped and air is supplied to the cleaning pipe, the air sent to the cleaning pipe reaches the gas sensor via the measurement pipe. Become.

Since the air that has reached the gas sensor does not contain alcohol gas from the sample, the gas concentration is zero.

Therefore, it is possible to extremely easily perform the zero point adjustment by stopping the air supply to the air supply pipe and setting the gas concentration detected by the gas sensor to zero when the air is supplied to the cleaning pipe.

Therefore, according to the present invention, continuous measurement can be performed, and not only can measurement not be impossible due to impurities in the sample during measurement, but also the zero point adjustment of the gas sensor can be performed at the gas concentration measurement position. It is.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing an apparatus according to the present invention. Also, in this figure, the same members as those in FIG.

In the figure, the alcohol concentration detecting device according to the present invention has a measurement pipe 20 and a temperature sensor 30 which are located in a sample 10 containing alcohol.

Further, an air supply pipe 21 extending from above the measurement pipe 20 to slightly inside the lower end of the measurement pipe 20 is provided in the measurement pipe 20.
And a washing pipe 26 for sending air into the inside of the measuring pipe 20 is provided.

Here, when the measurement pipe 20 is positioned in the sample 10 containing alcohol, the air supply pipe 21 is positioned in the sample 10 at the same time.

In addition, the cleaning pipe 26 is used to supply
When 20 is located in the sample 10 containing alcohol,
It is provided at a position that does not reach the sample 10.

Further, the air supply pipe 21 and the cleaning pipe 26 have a solenoid valve for switching.
A blower pump 25 is provided via 27, and by operating the blower pump 25, air can be sent out to the air supply pipe 21 or the cleaning pipe 26.

Further, the measurement pipe 20 is provided with a gas sensor 23 through a filter 22 as a protective material for the gas sensor 23 on the upper part thereof.
Is provided. In addition, around the filter 22, a blocking material
24 is provided, and the air that has risen inside the measurement pipe 20 is always discharged to the atmosphere via the gas sensor 23.

Here, the shape of the measurement pipe 20 and the air supply pipe 21 is not limited as long as they are pipe-shaped. Further, the material is required to be resistant to rust and not deteriorated by alcohol. Further, the length relationship between the measurement pipe 20 and the air supply pipe 21
Any length is acceptable as long as the gas from the sample becomes bubbles in the sample 10 and rises in the measurement pipe 20.

As the gas sensor 23, a contact combustion type gas sensor 23 or a semiconductor type gas sensor 23 is used.

The temperature sensor 30 can be used regardless of whether a semiconductor is used or not, as long as it can detect the temperature of the aqueous solution containing alcohol, which is the specimen 10.

Next, the operation of the alcohol concentration detecting device according to the present invention will be described.

First, the measurement pipe 20 and the temperature sensor 30 are inserted into the sample 10. At this time, the air supply pipe 21 in the measurement pipe 20 is located in the sample 10 at the same time, but the washing pipe 26 is located away from the sample 10.

After that, the electromagnetic valve 27 is switched to the air supply pipe 21 side, and air is blown into the air supply pipe 21 from the blower pump 25.

Then, this air is blown out from the lower end of the air supply pipe 21 into the sample 10, and the blown air turns into bubbles to form the measurement pipe 20.
It will rise inside.

At this time, in the measurement pipe 20, alcohol evaporated from the surface of the sample 10 in the measurement pipe 20 is present, and alcohol dissolved in bubbles rising in the sample 10 together rises in the measurement pipe 20. To the gas sensor 23.

Therefore, the alcohol concentration in the gas rising by the gas sensor 23 is measured.On the other hand, the temperature sensor 30 outputs the temperature information of the specimen 10, so that the temperature information based on the output temperature information is obtained. The output table from the gas sensor 23 that has been measured in advance is searched by a search unit (not shown), and the result is compared with the output from the gas sensor 23 by a comparison unit (not shown), and the alcohol concentration of the sample 10 is output to an output unit (not shown). Output.

It should be noted that the output here can be formed simply to display a numerical value, or an alarm can be issued when the concentration is outside a predetermined concentration range set in advance, or an instruction to add alcohol can be issued. it can.

Still further, the alcohol concentration measuring device according to the present invention,
By switching the electromagnetic valve 27, air from the blower pump 25 can be blown into the cleaning pipe 27.

In this way, the measuring pipe 20 is
Although the alcohol evaporated from the surface of the sample 10 in the sample 20 exists, the alcohol dissolved in the bubbles rising in the sample 10 does not exist.

Also, here, the alcohol evaporated from the surface of the sample 10 in the measurement pipe 20 is almost negligible with respect to the alcohol dissolved in the bubbles rising in the sample 10, so that the alcohol reaching the gas sensor 23 Has almost no alcohol.

Therefore, when the gas concentration is measured by operating the gas sensor 23 in this state, the alcohol gas concentration is measured in a state where there is no alcohol gas, that is, in the same state as in the air. Can be used for zero point adjustment of the gas sensor 23 with no alcohol gas present.

After the zero point adjustment of the gas sensor 23 is performed in this way, the solenoid valve 27 is switched again to
By blowing air into the air supply pipe 21 from above, the alcohol concentration in the sample 10 can be measured.

Further, the zero point adjustment of the gas sensor 23 is performed at the time of disclosure of use, 5 minutes, 10 minutes, 20 minutes, 30 minutes, 1 hour after the start of use, and 1 hour later, and thereafter, every other hour. Reliability can be ensured.

Such an alcohol concentration detection device according to the present invention,
Even if the insoluble matter is mixed in the specimen 10, there is no portion that is broken down by the insoluble matter, so that the sample 10 can be used stably for a long period of time.

In addition, compared to simply measuring the alcohol concentration by the alcohol evaporated from the surface of the sample 10, the alcohol dissolved in the bubbles from the air supply pipe 21 can be used for the measurement.
Even if the diameter of 20 is small, continuous measurement can be sufficiently performed.

Also, since the measurement pipe 20 is inserted into the sample 10, the sample 10
There is no measurement error caused by the flow of air.

Further, when the temperature of the sample 10 is different from the temperature of the air blown from the air blow pump 25, water droplets adhere to the air supply pipe 21 or the measurement pipe 20, and it is conceivable that accurate measurement of alcohol concentration cannot be performed due to the alcohol dissolved in the water droplets. But,
Since the temperature of the specimen 10 is measured by the temperature sensor 30, the above-mentioned adverse effects can be prevented by maintaining the air supply at the measured temperature.

Further, the alcohol concentration measuring apparatus according to this embodiment is
Since the zero point adjustment of the gas sensor 23 can be performed by simply switching the solenoid valve 27 while being kept in the center 10, the measurement under the optimum condition can be performed very easily.

In addition, the graph shown in FIG. 2 is a graph showing an experimental result when the zero point adjustment of the alcohol concentration detecting device according to the present invention is performed.

 This experiment shows the results obtained under the conditions of sample temperature; 22.7 ° C sample; alcohol; curve (A); sensor output curve at 200 mV / full; curve (B); 5 V / full This is the alcohol concentration output.

Further, in this graph, the Χ axis is a time axis, and the Y axis is a sensor output or an alcohol concentration output.

Further, point (C) in this graph shows a state where the alcohol concentration measuring device according to the present invention is pulled out from the sample 10. As described above, when drawing out from the sample 10, the air blow from the blower pump 25 is stopped before drawing out from the sample 10.

At the point (D), the measurement pipe 20 drawn out of the sample 10 and the temperature sensor 30 are put in water, and
This shows a state in which the blowing of air from is started. The reason why the alcohol gas concentration temporarily increases in this state is that
This is because the gas sensor 23 detects the alcohol gas remaining in the measurement pipe 20. Further, even when air is blown into the measurement pipe 20 by the blower pump 25 when it is drawn from the sample 10, it was difficult to completely remove the alcohol gas in the measurement pipe 20.

Further, the point (E) shows a state where the measurement pipe 20 and the temperature sensor 30 are immersed in water and measured without alcohol.

In the process from (C) to (E), the measurement pipe is actually
In the case where the sample 20 and the temperature sensor 30 are pulled out of the sample 10 and put in water, and the zero adjustment of the gas sensor 23 is to be performed, not only takes time to move from the sample 10 to the water, but also thereafter. However, the gas sensor 23 detects the alcohol gas remaining in the measurement pipe 20, and it takes a lot of time until a stable measurement state is obtained.

Compared with such a case, the point (F) is a part according to the gist of the present invention, and the electromagnetic valve 27 is switched while the measurement pipe 20 and the temperature sensor 30 are positioned in the sample 10 to blow air. This shows a state in which the air from the pump 25 is switched from the air supply pipe 21 to the cleaning pipe 26. As is clear from the experimental results, while the measurement pipe 20 and the temperature sensor 30 are positioned in the sample 10, the solenoid valve 27 is switched, and the air from the blower pump 25 is transferred from the air supply pipe 21 to the cleaning pipe 26. Just by switching, the alcohol gas in the measurement pipe 20 is instantaneously eliminated, and the same measurement result as in air can be obtained.

Further, the point (G) shows a state in which air is sent from the blower pump 25 only to the washing pipe 26. At this time, since the output is exactly the same as the point (E) described above, it can be confirmed that the same measurement result as that in the air is obtained. Therefore, in this state, the zero point of the gas sensor 23 can be confirmed.

In this experiment, the solenoid valve 27 was switched while the measurement pipe 20 and the temperature sensor 30 were positioned in the sample 10, and
The state in which the air from the blower pump 25 was switched from the air supply pipe 21 to the cleaning pipe 26 was repeated about every 5 minutes, but the values for zero confirmation were the same, and stable zero confirmation was performed. Was confirmed.

In the above description, ethyl alcohol and isopropyl alcohol have been described as examples of the alcohol in the sample 10, but it goes without saying that other alcohols can also be used.

Further, the air supply pipe 21 and the cleaning pipe 26 are provided with a blower pump 25 via a switching electromagnetic valve 27, and it has been described that air is sent to one of the blower pumps. A blower pump can be used by connecting each to the air supply pipe 21 and the washing pipe 26.

Further, between the blower pump 25 and the air supply pipe 21 and the cleaning pipe 26,
Directly connected via the solenoid valve 27, but if you want to reduce the amount of air blow, for example, provide an open valve between the blower pump 25 and the solenoid valve 27 to open part of the air blown into the air Thereby, it is possible to make it easy to adjust the air flow.

Further, when the gas sensor 23 is covered with a porous film that allows air to pass through but does not allow moisture to pass through and has high heat resistance, the gas sensor 23 is not damaged by moisture.

[Effects of the Invention] As described above, the present invention enables the zero point adjustment to be performed while the measurement pipe and the temperature sensor are positioned in the sample, and maintains the characteristics of the gas sensor constant. This eliminates a complicated operation for zero adjustment.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an alcohol concentration detecting device according to the present invention, FIG. 2 is a graph showing an experimental result when zero point adjustment of the alcohol concentration detecting device according to the present invention is performed, FIGS. FIG. 5 and FIG. 5 are schematic views showing a conventionally proposed alcohol concentration detecting device. 10 ………………………………………………………………………………………………………………………………………………………. Temperature sensor

Continuation of the front page (72) Inventor Yoshihiro Tsuruoka 1-5-1, Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd. (72) Inventor Toru Sudo 1-5-1-1, Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd. (56) References JP-A-58-158551 (JP, A) JP-A-3-2562 (JP, A) JP-A-3-61846 (JP, A) JP-A-3-273148 (JP, A) Kaihei 3-68848 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) G01N 27/00-27/12 G01N 1/22

Claims (1)

(57) [Claims] 1. A measuring pipe and a temperature sensor, which are located in a sample containing alcohol, and an air supply pipe which is simultaneously located in the sample when the measuring pipe is located in the sample. When the measurement pipe was placed in the sample, the washing pipe that sends out air to a position that did not reach the sample was installed, and the gas sent from the air supply pipe returned to the measurement pipe through the sample. An alcohol concentration detecting device provided with a gas sensor for measuring an alcohol concentration in a gas.