JPH025269B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water content measuring device in oil using an electrically insulated platinum filament as a detection end.

Conventionally, there have been few simple methods for measuring the water concentration in water-containing oil, and only the Karl Fischer method and a measuring method using a heated resistor are known. The Karl Fischer method requires complicated pretreatment, requires time and effort for measurement, cannot be measured continuously, and is limited in scope of application. In addition, the measurement method using a resistor is to immerse a heating resistor in water-containing oil and measure the change in resistance of the heating resistor as an output, which is used as a guide to the moisture concentration.Measurements using this method The vessels are commercially available as well known ones. However, this measuring device has problems in terms of accuracy and sensitivity, and is often impractical.

In the course of various studies on methods for measuring the water concentration in hydrous oil, the present inventors formed protrusions or recesses on the detection end made of a heating resistor, and also tilted the detection end into the hydrous oil. When the water-containing oil near the protrusions or recesses is heated to a temperature higher than the boiling point of water, bubbles will be concentrated in the protrusions or recesses, and the grown bubbles will rise along the detection end surface and separate. The present invention was completed by learning how to efficiently change the temperature of the detection end.The purpose of this invention is to easily and accurately measure the water concentration in water-containing oil with high sensitivity. The object of the present invention is to provide an apparatus for measuring water content concentration in oil.

1 and 2 for one embodiment of the present invention.
This will be explained with reference to the figures.

1 is a base on which a support column 2 is erected;
A first arm 3 and a second arm 4 are connected to the upper part of the holder so as to be able to rotate freely in sequence. A clamp 5 is attached to the tip of the second arm 4, and the upper side of the detection end holder 6, which has a cylindrical shape with a bottom, is clamped by the clamp 5. The upper side of an insulator 9a made of glass and having a protrusion 8 formed on the lower side is inserted into the bottom wall 7 of the holder 6, passing through the bottom wall 7. A platinum wire filament 10 is melt-sealed inside the insulator 9a, and the insulator 9a and the platinum filament 10 constitute the detection end 9, and the lead wire 11 of the filament 10 extends from the upper end of the detection end 9. drawn into the holder 6, passed through the holder 6, and guided to the outside from its upper end;
It is further connected to the electrical section 12. Note that 13 is a recorder connected to the electrical section 12, and the measurement results are displayed here.

Furthermore, a protection tube 14 is attached to the lower part of the holder 6, with the detection end 9 housed therein. This protective cylinder 14 has two communication holes 15, 15 formed along the axial direction in the cylinder wall, and the protrusion 8 and one of the two communication holes 15, 15 are connected to each other. are mounted on the holder 6 facing each other.

Next, using the measuring device with the above configuration, the beaker 1
To explain the case of measuring the water concentration in the water-containing oil 17 in the water-containing oil 17 in the water-containing oil 17, first, the second arm 4 is tilted,
The detection end 9 is set at 30 degrees with respect to the perpendicular direction (θ=
30 degrees) and adjust the holder 6 by rotating it around the axis so that the protrusion 8 is positioned above the detection end 9. In this state, the detection end 9 is exposed to the hydrous oil
Soak in 7. Next, electric power is supplied from the electric section 12 to the filament 10, which causes the filament 10 to generate heat and the detection end 9 to be heated to about 110°C. Then, the hydrous oil 17 near the detection end 9 is locally heated without heating the entire hydrous oil 17, and bubbles 18 are formed on the contact surface between the detection end 9 and the hydrous oil 17 due to evaporation of water in the hydrous oil 17. occurs and grows, but this tendency is particularly strong in protrusion 8,
Air bubbles 18 are generated substantially only from the protrusions 8. During the generation and growth period of the bubbles 18, heat is radiated from the detection tip 9 through a temperature boundary layer formed near the surface of the detection tip 9, and the amount of heat generated and the amount of heat radiation are balanced at the detection tip 9. It is maintained at a constant temperature. When the bubble 18 grows to a size larger than a certain diameter, a large buoyant force acts on the bubble 18, which causes the bubble 18 to move diagonally upward along the side wall of the detection end 9, and finally from the detection end 9. Detach and protect tube 1
After being released into the water-containing oil 17 from the communication hole 15 of 4, the bubble floats upward in the water-containing oil 17, and as the bubble moves obliquely upward along the side wall of the detection end 9, it is detected. The temperature boundary layer formed near the side wall of end 9 is stirred. Therefore, the detection end 9 is temporarily cooled by the low-temperature water-containing oil 17 located far from the detection end 9 (outside the temperature boundary layer).
This temperature change is transmitted to the filament 10 and its resistance value is temporarily reduced. after that,
When the bubbles are removed and the temperature boundary layer is no longer stirred by the bubbles, the filament 10 is raised to the above-mentioned constant temperature again, and a temperature boundary layer is formed near the surface of the detection end 9, and the bubbles 18 are moved to the surface of the protrusion 8. It regenerates from the part and grows repeatedly. Then, the temperature change of the filament 10 is reflected in the electric part 1 as a change in the resistance value of the filament 10.
2 and recorder 13 as a pulse output.
In this case, the sum of pulse heights or pulse areas within a unit time displayed on the recorder 13 has a correlation with the water concentration in the hydrous oil, and these pulse heights or pulses By measuring the total area within a unit time, the water concentration in hydrous oil can be measured with high accuracy.

In this embodiment, the filament 10 is sealed and insulated in the glass insulator 9a, thereby forming the detection end 9. Therefore, the detection end 9 can be easily heated by supplying electric power to the filament 10. At the same time, the temperature change at the detection end 9 is detected by measuring the resistance value of the filament 10. Therefore, the structure of the detection end 9 is simple, and it is extremely compact and easy to handle. Not only that, but the response speed is also fast. Also,
Since the detection end 9 is arranged at an angle of 30 degrees with respect to the perpendicular direction, the bubbles 18 move obliquely upward along the upper wall of the detection end 9, and sufficiently stir the temperature boundary layer.
Therefore, the temperature change at the detection end 9 becomes large, and the detection sensitivity is improved. In addition, since the protrusion 8 is formed near the lower end of the detection end 9, the distance that the bubbles 18 generated with the protrusion 8 as a nucleus moves diagonally upward along the detection end 9 is increased, and the temperature change at the detection end 9 is also increased. Therefore, the detection sensitivity is improved, and since the moving distance of each bubble 18 moving along the detection end 9 becomes equal, the variation in the temperature change of the detection end 9 due to each bubble 18 is reduced, and therefore the measurement accuracy is improved. will improve. Furthermore, since the protective tube 14 is installed to cover the detection end 9, external disturbances are less likely to be applied, and the S/
This improves the N ratio.

In this embodiment, the detection end 9 is arranged at an angle of 30 degrees with respect to the perpendicular line, but the present invention is not limited to this.
Although it can be arranged at any angle, in general, θ in FIG.
= 30 to 50 degrees is preferable. Further, although the detection end 9 is formed by enclosing the filament 10 in the glass insulator 9a, the present invention is not limited to this, and any suitable structure, shape, and material may be adopted. Further, although the protrusion 8 is formed at the detection end as a nucleus for generating the bubble 18, a recess may be formed, and other modifications may be made without departing from the gist of the present invention.

Accordingly, the present invention provides a detection end in which the surface of a platinum filament is coated with an insulator, a protrusion or a recess is formed in the insulator, a predetermined electric power is supplied to the filament, and an electric part that electrically detects and outputs changes in electrical resistance, and supplies a predetermined power to the filament while immersing the filament in water-containing oil with the detection end tilted with respect to the vertical direction. The detection end generates heat, thereby heating the water-containing oil near the protrusion or recess to a temperature higher than the boiling point of water, generating evaporation bubbles of water at the contact surface between the protrusion or recess and the water-containing oil, and causing the bubbles to evaporate. When the bubbles grow and rise along the surface of the sensing end from the protrusion or recess and leave, the filament changes the temperature of the sensing end caused by the bubbles stirring the temperature boundary layer formed near the peripheral wall of the sensing end. Since the structure is configured so that the electrical part electrically detects and outputs the change in resistance value, 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.
Furthermore, even if the water-containing oil is colored or has high turbidity, the measured values obtained will not be affected by these conditions. can be easily measured, and since the measurement is performed using non-fractured pocket spectroscopy and no reagents are added, there is no possibility of contaminating the water-containing oil with reagents or the like. Furthermore, since it can perform continuous measurements, it has the advantage of being useful in various fields such as process control.

Example The water concentration in engine oil was measured using the above device. In this case, the insulator 9a of the detection end 9 was made of glass with an outer diameter of 1.6 mm and a length of 13 mm, a platinum filament was melt-sealed therein, and a current of about 65 mA was passed through it. In addition, samples were prepared by using commercially available engine oils (10W-30, 20W-40, manufactured by Etsuo Corporation) by adding a calculated amount of water to each, and shaking thoroughly.

The measurement results are shown in FIGS. 3 and 4.

[Brief explanation of drawings]

FIG. 1 is a side view showing an example of an oil water content measuring device used in carrying out the present invention, FIG. 2 is a partially enlarged cross-sectional side view showing the detection end of the same example, and FIGS. 3 and 4 are 3 is a graph showing the relationship between the water concentration in hydrous oil and the response output, each measured using the same device. 9...Detection end, 9a...Insulator, 10...Filament, 12...Electrical part, 17...Hydrous oil, 1
8...Bubbles.

Claims (1)

[Scope of Claims] 1. A detection end formed by coating the surface of a platinum filament with an insulator and forming a protrusion or a recess in the insulator, and supplying a predetermined electric power to the filament and an electric resistance of the filament. and an electric part that electrically detects a value change and outputs it, and the detecting end is immersed in water-containing oil at an angle with respect to the vertical direction while supplying a predetermined power to the filament. generates heat, thereby heating the hydrous oil near the protrusion or recess above the boiling point of water, generating evaporation bubbles of water at the contact surface between the protrusion or recess and the hydrous oil, and causing the bubbles to grow. The temperature change at the sensing end caused by the bubbles stirring the temperature boundary layer formed near the peripheral wall of the sensing end when rising and leaving the protrusion or recess along the sensing end surface is expressed as the resistance value of the filament. 1. A water content measuring device in oil, characterized in that the change is electrically detected by an electric section and outputted. 2. The device according to claim 1, wherein the detection end is inclined at 30 to 50 degrees with respect to the vertical direction. 3. The device according to claim 1 or 2, wherein the detection end is housed in a protective cylinder.