JPS62200241A - Method and device for detecting or measuring liquid system component - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method and apparatus for measuring the concentration of volatile oxidizing components in a liquid system.

BACKGROUND OF THE INVENTION In many industries, particularly in the brewing industry, it is necessary to be able to measure the concentration of volatile oxidizing components in liquid systems, such as the ethanol concentration. There is, of course, a need for this in the wine and alcohol industry as well as in other areas including yeast, fruit storage and soft drinks. Until now, the main methods for detecting such volatile oxidizing components have been distillation, liquid hydrometer and gas-liquid chromatography. Furthermore, fuel cells are used in the field of breath alcohol testing. In practice, each method has a number of drawbacks: on the one hand, it is time-consuming; on the other hand, it requires very complex equipment and technical skill.

It has also been proposed to measure such components by static head space analysis, but this method requires considerable skill and time.

[Purpose of the invention]

An object of the present invention is to provide a method and apparatus for measuring volatile oxidizing components in a liquid system that can be used in a short time and does not require skill.

[Summary of the invention]

The present invention allows the generated gas to flow through or in contact with a dilute liquid solution, and introduces the generated gas, vapor mixture, or a sample thereof to an electric gas sensor to inspect and measure the concentration of components in the liquid system. be.

Preferably, the sample is introduced to the gas sensor, which is an electrochemical fuel cell, after reaching equilibrium.

In the method described above, the gas sensor is calibrated after obtaining an indication of the component concentration of the standard. In this case, measure the temperature difference between the standard solution and the measurement solution, and adjust the scale according to the temperature difference.

Advantageously, this gas bubbles through the liquid system. In that case, the bubble diameters are 0.25mm and 0.75mm
It is preferable to pass for 1.5 to 3 minutes at a rate of 250 to 350 cm' per minute.

To maintain linearity of gas sensor operation, the dilution of the liquid system is varied depending on the expected concentration, and the output of the gas sensor is amplified to compensate for the dilution. For example, if the gas component is ethanol and the volume of the diluted solution is 10
0 cm', then the volume of the liquid system in solution is
2cm when the expected concentration (of the liquid system) is 566v/v
, 1 cm3 for 10% v/v, 0.
At 5 cm3 and 40% v/v, it is 0.25 cm', and is proportional to this from now on.

Particularly in foaming liquid systems such as beer, it is desirable to add an antifoaming agent before the gas passes through the solution.

Another object of the present invention is an apparatus for detecting and measuring volatile oxidizing components in a liquid system. The apparatus includes a liquid container for receiving a diluted sample of the liquid system, a means for gas passing through or adjacent to the liquid system to appear in a gas space adjacent to the liquid system, and furthermore for determining the concentration of components in the generated gas vapor mixture. It consists of means including an electrical gas sensor for detecting and measuring.

The gas space consists of a head space defined at least in part by the liquid container, and the means for passing the gas through the liquid system includes an air pump to bubble the generated gas through the diluted sample. .

The device further comprises a container for the standard component, means for the gas passing through or in contact with the standard solution to appear in a gas space adjoining the liquid system, and means for delivering at least one sample of the evolved gas to an electrical gas sensor. Preferably, the method comprises means for adjusting the gas sensor according to the component concentration measured from the standard solution.

Additionally, the apparatus includes means for measuring the liquid temperature difference in the container and correcting the output of the gas sensor accordingly. Additionally or alternatively, the apparatus includes a variable amplifier for amplifying the output of the sensor and means for varying the amplification according to the dilution of the liquid system in solution.

The apparatus includes means for automatically proceeding to obtain multiple indications of the concentrations of components of the liquid system.

In that case, means are provided for indicating the average of the series of readings.

The device is portable and includes an air pump, an electric valve, and an electrical fuel source.

Although the invention has been defined above, it also includes combinations of the features mentioned above or below.

The present invention can be implemented in various fields.

[Embodiments of the invention]

As mentioned above, the device has many uses, but for the sake of simplicity, it will be described in detail with reference to the accompanying drawings with reference to the detection of ethanol in alcoholic beverages.

When a liquid sample is placed in a container with a gas space at the top, volatile substances evaporate and become gas, eventually reaching an equilibrium state. In this state, the concentration of volatile components in the liquid is directly proportional to the gas concentration. It has been found that if a gas bubbles through a liquid system, the system quickly reaches equilibrium, so head space measurements can be made quickly by this simple technique. An apparatus for measuring the ethanol concentration of a diluted sample of an alcoholic beverage is shown in FIG. 10. This device is a frame 11 that limits a room 12 near a door 13.
Consists of. Inside the chamber 12 is a container 14 with a head space as shown in detail in FIG. ．． 15 have been installed. The containers 14, 15 are actually the same, so for convenience only container 14 will be described.

As can be seen in FIG. 2, the container 14 has a bulbous reservoir 16 for receiving the diluted liquid sample, which is discarded after measurement through the liquid outlet valve 17. A tube 18 extends into the reservoir 16 and has an outlet 19 near the bottom of the container. This tube is the air inlet and leads the thermocouple into the solution. A neck 20 follows the reservoir, the upper end of which is closed with a plastic stopper, and an air outlet 21 on the side.
There is. A scale 22 is placed on the neck 20 and indicates a volume of 1100 C' when the reservoir is filled to this point.

Figure 3 shows the flow of operation of this device. Air pump 23 supplies air to air intake 24 at a rate of approximately 300 cm' per minute. This intake is regulated by a two-way cock 25, directing air to either branch 26, 27.

First, connect it to the air intake port 18 of the passenger device 14, then connect it to the container 1.
Connect to the air intake port No.5. The air outlet 21 of each container 14.15 is connected to a T-pipe 28 via a respective valve 29.30. The leg of the T tube becomes the air outlet 31, and the sampling needle 32 of the electrochemical fuel cell 33 is located at the intersection 34 of the T.

The output of the fuel cell 33 passes through an amplifier 35, a processing correction circuit 36, and a count display 37. The amplification of the amplifier can be adjusted by a plurality of switches 38. This regulation is desirable because it is difficult to provide fuel cells that operate linearly over a wide range of concentrations.

Therefore, it is desirable to adjust the dilution of the sample according to the expected ethanol concentration and adjust the amplification to compensate for the ethanol concentration.

In use, standard ethanol is pipetted into the water in container 14, but the entire container is first washed. After adding ethanol, add water up to mark 22. The same amount of the beverage to be tested, for example beer, is placed in the container 15 and similarly diluted with water. The switch 39 then turns on the air pump 23.
, and turn the cock 25 to move the air in the direction 26 to create bubbles and quickly establish an equilibrium state between the ethanol standard solution and the head space. After about 2 minutes, an equilibrium condition is established, then valve 29 is opened and a sample of the extracted bent space is collected at fuel cell 33 as it passes through T-tube 2B. The sample concentration is detected by an electric circuit 36 and compared with the set value of the standard solution. If there is any deviation, the fuel cell output is corrected. After cleaning the T-pipe 28 for a short time, the cock 25 is operated to send air into the container 15. Similar operation continues with the fuel cell receiving a sample of head space gas from vessel 15.

To check that the fuel cell is calibrated correctly,
It is desirable to run another correction cycle. If this adjustment is not made, the device will give an erroneous reading.

Headspace concentration is very temperature sensitive. Therefore, the temperature of the liquid sample is measured with a thermocouple, and the output signal of the fuel cell 33 is corrected in the electric circuit 36 according to the temperature difference.

The container is maintained at a constant temperature using a thermostatic heater.

When testing wine, a similar procedure is used except that switch 38 is placed in a different range due to the high alcohol content of the wine. In this case, a small amount of wine is placed in the container 15.

The dilution number corresponding to the predicted approximate concentration is as described above.

(Effects of the invention) This device is portable and allows quick and accurate concentration readings.
It is recognized that it can be obtained anywhere without the need for complicated techniques. For example, in Portugal, where boat wine is produced, concentrations can be measured on the backs of horses, even on remote farms where, to date, no scientific quality control has been carried out.

The rationale for the invention and the associated measurement technique is based on the fact that there is a constant ratio between the alcohol concentration of the vapor of the solution and the alcohol concentration in the solution. In other words, it follows Henry's law. The so-called distribution ratio depends, among other factors, on temperature and therefore requires precise temperature control or temperature measurement and correction.

The distribution rate is also affected by other substances in the fermented alcoholic beverage, such as sugars and other dissolved substances. but,
When diluting the alcoholic beverage, for example by a factor of 100, these effects are negligible. This is because the high sensitivity of the fuel cell sensor makes it possible to measure alcohol at low concentrations and is not affected by impurities.

The present invention also incorporates a system for accurately and automatically diluting samples taken continuously or semi-continuously.
Also, by continuously or semi-continuously feeding a diluted solution into an analysis container, experiments can be carried out to continuously measure the amount of alcohol in a liquid during processes such as fermentation or mutual mixing with other liquids. It can also be applied to equipment and technology.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an apparatus for measuring the concentration of volatile oxidizing components in a liquid system. FIG. 2 is an enlarged schematic diagram of a head spaced container for the present device. FIG. 3 is a schematic flowchart of the apparatus. 11...Frame 12...Room 13...
·door

Claims (1)

[Claims] 1. Flowing a gas through or contacting a gas stream into a dilute solution of a liquid system and contacting the resulting gas vapor mixture or a sample thereof with an electric gas sensor, A method for detecting or measuring a volatile oxidizing component in a liquid system, the method comprising obtaining an indication or a measured value of the concentration of the component in the liquid system. 2. The method according to claim 1, wherein the sample is brought into contact with a gas sensor when the sample is in an equilibrium state. 3. The method according to claim 1 or 2, which comprises correcting the gas sensor by obtaining a reading of a component concentration that serves as a component standard. 4. The method according to claim 3, which comprises measuring the temperature difference between the standard solution and the measurement solution and adjusting the scale according to the temperature difference. 5. The method according to any one of claims 1 to 4, wherein gas is bubbled through the liquid system. 6. The method according to claim 5, wherein the bubble diameter is between 0.25 mm and 0.75 mm. 7. The method according to claim 5 or 6, wherein the gas is bubbled for 1.5 to 3 minutes at a rate of 250 to 350 cm^3 per minute. 8. The method according to any of claims 1 to 7, wherein the dilution of the liquid system is varied according to its expected concentration, and the gas sensor output is amplified to compensate for the dilution. 9. The component of the liquid system is ethanol, the volume of the diluted solution is 100 cm^3, and the expected concentration of the liquid system is 5%.
When v/v, the volume of the liquid system in the solution is 2 cm^3,
When it is 10% v/v, it is 1 cm^3, when it is 20% v/v, it is 0.5 cm^3, and when it is 40% v/v, it is 0.2.
5cm^3, and the method according to claim 8, in which the same proportional relationship is applied thereafter. 10. A method according to any of claims 1 to 9, comprising adding an antifoam agent to the solution before passing the gas into the solution. 11. A container for receiving a diluted sample of a liquid system, means for passing a gas into or in contact with the liquid system and introducing it into a gas space in contact with the liquid, for determining the concentration of components in the generated gas vapor mixture. 1. A device for detecting and measuring volatile oxidizing components in a liquid system, comprising means including an electric gas sensor for detecting and measuring. 12. The apparatus of claim 11, wherein the gas space is a head space defined at least in part by the liquid container. 13. Apparatus according to claim 11 or 12, wherein the means for passing gas into the liquid system comprises an air pump for bubbling the gas through the diluted sample. 14. A second container for the standard component, means for passing or bringing the gas into contact with the standard solution and guiding it into the gas space in contact with the liquid system, means for sending at least a sample of the generated gas to the electric gas sensor, the standard component. 14. The apparatus according to any one of claims 11 to 13, comprising means for adjusting the gas sensor according to the concentration of a component measured or detected from the gas sensor. 15. Means for measuring the temperature difference of the liquid in the container;
and means for correcting the output of the gas sensor according to the temperature difference. 16. Apparatus according to any one of claims 11 to 15, comprising a variable amplifier for correcting the output of the sensor and means for varying its amplification according to the dilution of the liquid system in the solution. 17. Apparatus according to any one of claims 11 to 16, including means for automatically performing operations for obtaining a series of readings of the concentrations of components of the liquid system. 18. The apparatus of claim 17 including means for displaying the average of the readings. 19. The device according to any one of claims 11 to 18, wherein the device is portable and includes an air pump, an electric valve, and an electric fuel source.