JPH0245815B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring the water concentration in hydrous oil. More specifically, the present invention relates to a method for measuring the water concentration in hydrous oil, and more specifically, the hydrous oil is locally heated using a heating element, and thereby the heating element and the hydrous oil are heated. This invention relates to a method for determining the water concentration in hydrous oil by observing evaporation bubbles of water generated on a contact surface.

Conventionally, there have been few simple methods for measuring the water concentration in water-containing oil, and only a few known methods include the Karl Fischer method and a measuring method based on resistance change of a heated resistor. The former method requires complicated pretreatment, requires time and effort for measurement, and has problems such as not being able to perform continuous measurements and having a limited range of application. In the latter method, a heating resistor is immersed in water-containing oil, and the resistance change that occurs when the water in the oil evaporates on the surface of the heating resistor is measured as an output, and that output is used as a guide for the water content. There is something to do.
Measuring instruments using this method are well known and commercially available, but they have the drawback of large errors due to electrical noise.

In the course of various studies on moisture content research using the latter method, the inventor of the present application discovered that when a heating body is brought into contact with hydrous oil and the hydrous oil near the heating element is heated to a temperature higher than the boiling point of water, the hydrous oil The present invention was completed based on the knowledge that there is a certain relationship between the number of bubbles due to evaporation of water generated at the contact surface between the oil and the heating element and the water concentration in the water-containing oil. The purpose is to provide a method for easily and accurately measuring the water concentration in hydrous oil. In this case, in the present invention, the correlation between the number of bubbles and the moisture concentration at a specific heating temperature of the hydrous oil to be measured is investigated in advance, and the moisture concentration is determined based on this correlation. For example, when measuring oil with a low water concentration, it is necessary to heat the surface of the heating element to around 120°C and heat the oil near the heating element to a high temperature of around 120°C in order to generate many bubbles. In this case, the correlation between the number of bubbles and the water concentration when the oil is heated to 120°C is investigated in advance. Also, when measuring oil with a high moisture concentration, it is sufficient to heat the surface of the heating element to about 110°C and then heat the oil near the heating element to about 110°C.
In this case, the correlation between the number of bubbles and the water concentration when the oil is heated to 110°C is investigated in advance. Therefore, according to the present invention, the moisture content can be immediately determined from the number of bubbles by simply observing the number of bubbles.

Hereinafter, one embodiment of the present invention will be described with reference to FIG.

Figure 1 shows an example of a water-containing oil measuring device used in carrying out the present invention.
This is a measurement tank that satisfies the following conditions. Inside the tank 1, a detector holder 4 and a hollow sound receiving tube 5 are vertically arranged and fixed in parallel by arms 3a and 3b attached to the inner wall of the tank. At the lower end of the holder 4, a heating element 8 is mounted which has a filament 7 built into a cladding tube 6 made of glass, metal, or other material.
A lead wire 9 drawn out from this heating body 8 passes through the inside of the holder 4 and is connected to an electric section 10, and a predetermined electric power is supplied from the electric section 10 to the filament 7 via this lead wire 9. As a result, the heating element 8 is heated to about 110°C.

The lower side of the sound receiving tube 5 is bent at approximately 90 degrees at a predetermined point, and a sound receiving portion 11 with a slightly larger diameter is formed at the end thereof, so that an open end 12 of the sound receiving portion 11 is formed. is arranged facing the heating element 8.
Further, a sound receiving element 13 such as a microphone that detects sound and sends out an electrical signal corresponding to the volume is attached to the upper part of the sound receiving tube 5, and the sound received by the sound receiving section 11 is The sound receiving element 1 passes through the sound tube 5.
3, where it is converted into an electrical signal and sent to the electrical section 10. The signals thus sent to the electrical section 10 are processed here, and sent to the recorder 14, where the results are recorded. Note that 15 is a cable that transmits the electrical signal from the sound receiving element 13 to the electrical section 10.

When measuring the water concentration in water-containing oil using this device, first, water-containing oil 2, which is a sample to be measured, is placed in measurement tank 1. As the water-containing oil 2, various oils such as engine oil, cutting oil, quenching oil, cooking oil, etc., in which water at a low concentration of ppm order is dispersed or dissolved, can also be measured. Next, a predetermined electric power is supplied from the electric section 10 to the filament 7, whereby the filament 7 generates heat and the temperature of the heating element 8 reaches about 110°C. Then,
The hydrous oil near the heating element 8 is heated to a temperature higher than the boiling point of water, and as a result, bubbles 16 are generated at the contact surface between the heating element 8 and the hydrous oil 2 due to evaporation of the water in the hydrous oil 2.
However, the amount of bubbles 16 generated (number of bubbles generated) has a correlation with the water concentration in the hydrous oil 2. Then, when the bubble 16 is generated, the bubble 16
This generated sound is guided into the sound receiving tube 5 through the open end 12 of the sound receiving section 11 disposed opposite the heating body 8, and is guided into the sound receiving tube 5. The sound reaches the sound receiving element 13, where it is converted into an electrical signal corresponding to the generated sound volume and sent to the electrical section 10, where the signal is processed and then sent to the recorder 14.
This displays the water concentration in the hydrous oil.

According to this embodiment, the hydrous oil 2 is locally heated by the heating element 8, and the bubbles 16 generated thereby.
When observing the number of bubbles 16, the sound produced by the bubbles 16 is measured, so even if the hydrous oil 2 is colored or contains floating objects, etc., the hydrous oil 2 can be measured without being affected by these. The moisture concentration inside can be measured accurately and with high sensitivity. Furthermore, the heating body 8 and the sound receiving section 11
Since it can be made compact, it is convenient and easy to incorporate into various devices.

Further, as shown in FIG. 2, a filament 7 is buried in one side wall of the measuring tank 1, and a part of the side wall is used as a heating element 8, and air bubbles 16 are generated at the contact surface between the heating element 8 and the water-containing oil 2. In order to observe the generated sound, it is sufficient to immerse only the sound receiving tube 5 in the water-containing oil 2, resulting in a simple structure.

FIG. 3 shows an apparatus for measuring water concentration in hydrous oil used in another embodiment of the present invention. The parts 18 are mounted facing each other, and when the bubbles 16 generated by the heating of the heating element 8 pass between the light emitting part 17 and the light receiving part 18 and rise, the light emitted from the light emitting part 17 to prevent this light from reaching the light receiving section 18,
The number of bubbles 16 is observed by measuring the change in the amount of arriving light caused by this with the light receiving section 18 and sending the obtained electrical signal to the electrical section 10.
The rest of the configuration is the same as the measurement device described above, so
Identical parts will be given the same reference numerals and their explanations will be omitted.

In this example, since the number of generated bubbles is optically observed, by blocking incident light from the outside, it is possible to completely prevent the intrusion of noise from the outside, and to detect moisture with high sensitivity. Concentration can be measured. Furthermore, by using inexpensive and highly sensitive semiconductor elements for the light emitting section 17 and the light receiving section 18, the structure can be simplified. Furthermore, it is also possible to use a method such as using laser light as the light and measuring the scattered light.

Note that in the explanation of FIG. 3, the light emitting section 17 and the light receiving section 1 are
Although the scattering of incident light by bubbles has been explained in principle in Section 8, in practice, it goes without saying that general optical techniques can be used, such as using a lens system to focus the incident light on the bubble generation area.

FIG. 4 shows an apparatus for measuring water concentration in hydrous oil used in still another embodiment of the present invention.
A pair of electrodes 19 and 20 are placed above and immersed in hydrous oil 2, and air bubbles 16 generated by heating by filament 7 penetrate these electrodes 1.
The number of bubbles is observed by detecting the change in the dielectric constant between the electrodes 19 and 20 as they rise between the electrodes 9 and 20, and the other configurations are the same as the device described above.

In the various embodiments described above, the bubbles 16
Since the number of bubbles is directly observed, the structure is simple, and the number of large and small bubbles can be counted.
Essential digital measurements are possible. Furthermore, the correspondence between counting and moisture is clear, and the physical content of the measured values is clear, so future development can be expected.

In each of the above embodiments, electric power is used to heat the heating element 8; however, the heating element 8 is not limited to this, and various heat sources such as high-temperature steam can be used. It is not necessary, and for example, a heating element and a bubble observation part integrated may be directly immersed in the measurement place for measurement, and various other modifications may be made without departing from the gist of the present invention.

Thus, the present invention brings a heating element into contact with hydrous oil and heats the hydrous oil near the heating element to a temperature higher than the boiling point of water, thereby generating evaporation bubbles of water at the contact surface between the hydrous oil and the heating element. At the same time, the water concentration is determined by observing the number of bubbles generated. Therefore, the water concentration in water-containing oil can be measured in an extremely short time and easily, and the measured value is accurate. It is something. Furthermore, according to this method, the measurement is a non-destructive analysis and no reagents or the like are added, so there is no possibility of contaminating the water-containing oil. It also has the advantage of being able to carry out continuous measurements and can be used in various fields such as process control.

[Brief explanation of drawings]

FIGS. 1 to 4 are side sectional views each showing an apparatus for measuring water concentration in hydrous oil used in carrying out the present invention. 2... Water-containing oil, 8... Heating body, 10... Electric part, 13... Sound receiving element, 16... Bubbles, 17...
Light emitting part, 18... Light receiving part, 19, 20... Electrode.

Claims (1)

[Claims] 1. By bringing a heating body into contact with hydrous oil and heating the hydrous oil near the heating body to a temperature higher than the boiling point of water, evaporation bubbles of water are created at the contact surface between the hydrous oil and the heating element. In a water-containing oil, the water concentration in the water-containing oil is determined from the correlation between the number of evaporated bubbles and the water concentration in the water-containing oil at the heating temperature. Moisture concentration measurement method. 2. The measuring method according to claim 1, wherein the number of bubbles is observed by detecting the sound of bubbles. 3. The measuring method according to claim 1, wherein the number of bubbles is observed by detecting changes in the amount of light transmitted or scattering by the bubbles. 4. The measuring method according to claim 1, wherein the number of bubbles is observed by detecting a change in the dielectric constant of hydrous oil due to the bubbles.