JPS6035028B2 - oxygen analyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention applies to nitrogen gas, which is used as a shielding gas for oxygen prevention in the textile and glass industries, etc.
This invention relates to the improvement of an analyzer for detecting the amount of oxygen contained in various gases such as inert gases such as argon gas and other gases such as hydrogen gas, which are used as atmospheric gas during various heat treatments of metals.

Generally, this type of oxygen analyzer uses the principle of a galvanic cell, which uses noble metals such as platinum or silver for the cathode, metals such as cadmium or lead for the anode, and alkaline electrolytes such as caustic potash or caustic soda as the electrolyte. It is configured.

A typical oxygen analyzer using the principle of a galvanic cell employs a method in which a sample gas is blown into an electrolytic solution, humidified, mixed, and brought into contact with an electrode in the form of bubbles. However, if the sample gas is not sufficiently humidified and mixed into homogenized bubbles, contact with the electrode is unstable, resulting in unstable electrode current values and poor reproducibility. SUMMARY OF THE INVENTION An object of the present invention is to provide a signature oxygen analyzer that improves the above-mentioned drawbacks. That is, the present invention provides a galvanic cell having an anode in the form of a cylindrical elongated rod whose electrode portion is immersed in an electrolyte and made of, for example, cadmium or lead, and a disc of, for example, silver or platinum, which is not immersed in the electrolyte, inside the anode. In an oxygen analyzer, a cathode arranged spirally in the center of the cell is provided, and a porous humidifying tube made of an inert material whose lower end is immersed in the electrolyte is provided between the two electrodes, {a) Two or more partition plates having small holes at positions that are not immersed in the electrolytic solution in the porous humidifying tube are spaced apart from each other. The present invention is characterized in that both the pongee hole plate and the partition plate are provided in the porous humidifying pipe.

The present invention will be explained with reference to the drawings.

For convenience, an oxygen analyzer is shown that is provided with both a pongee hole plate and a partition plate, but it may be provided with only one of them as described above.

FIG. 1 is a sectional view showing an embodiment of the present invention, in which a sample gas is blown into an electrolytic solution through a sample gas inlet 2 provided at the bottom of a galvanic cell body 1.

3 is a porous humidifying tube made of an inert material, and a porous plate 4 is provided in the humidifying tube 3 at a position such that it is immersed in the electrolytic solution.

The sample gas injected from the inlet 2 passes through the holes in the hole plate 4 and is diffused over the entire surface of the electrolyte on the top of the hole plate 4, resulting in sufficient humidification and mixing. The electrolyte reaches the surface of the electrolyte as homogenized bubbles.

In this case, a layered portion of the sample gas is formed under the perforated plate, and uniform humidification and mixing is performed during the layered portion. Providing one pongee hole plate is enough to achieve the purpose. The appropriate size of the pongee hole is 0.05 to 0.5 skin. The number of pongee holes is arbitrary. Also, instead of providing the pongee hole plate, for example, a hole plate with a diameter of 0 is placed in a position that will not be submerged in the electrolyte.
．． It is preferable that two or more partition plates 5 made of epoxy resin, for example, each having one small hole on the 05 to 0.5 side, be provided, and the positions of the small holes should be as far away from each other as possible on the upper and lower partition plates. Most preferably, the small holes in the partition plate have a phase angle of 1800 degrees with respect to the center of the partition plate.

At this time, in the chamber 6 formed between the partition plates, the sample gas is effectively spread and further homogenized by the turbulent action. When two to four partition plates 5 are provided, there is no pressure loss and the sample gas is most effectively homogenized. It is preferable to provide the pongee hole plate and two or more partition plates at the same time. In this way, the sample gas is humidified, mixed and homogenized, and then passes through the spiral space of the cathode 7, which has 6 to 8 stages of spiral silver plates inscribed in the porous humidifying tube 3. It reaches the surface of the cathode 7.

On this surface, oxygen in proportion to the oxygen partial pressure in the sample gas reacts with moisture in the scale liquid sucked up by capillary action in the porous humidifying tube 3 to form hydroxyl ions. (Silver cathode) 02
The hydroxide ions pass through the porous humidifying tube 3 on the 12th, 20th, and 40th, dissolve into the electrolyte, and move toward the anode 8 made of cadmium (cadmium anode). Cadmium is oxidized to cadmium hydroxide as shown in the formula in the 20th history.

When the hydroxide ion loses its negative charge in this way,
A current proportional to the oxygen concentration in the sample gas flows from the cathode 7 to the anode 8 in an external circuit. Therefore, by measuring this current with the indicator 9, the oxygen concentration of the sample gas can be measured. Further, the sample gas after measuring the oxygen concentration is discharged to the outside from the exhaust port 10. Next, FIG. 2 is a measurement graph when a sample gas is blown into a conventional porous humidifying tube.

Moreover, FIG. 3 is a measurement graph in which only a pongee hole plate is provided in the porous humidifying tube. FIG. 4 shows a measurement graph when the pongee hole plate and the spacing plate are provided according to the embodiment of the present invention. When neither a pouch plate nor a partition plate is provided in the porous humidifying tube, the time from passage of the sample gas to the response is long, and the obtained data varies widely. However, by providing the pongee hole plate, the time from the passage of the sample gas to the response is considerably shortened, and the variation in the obtained data is also small. Both are further improved when a pore plate and a partition plate are provided within the porous humidifying tube. As is clear from the drawings, the present invention provides a porous humidifying tube made of an inert material with a porous plate and/or a partition plate at a position where the tube is immersed in the electrolyte, so that the electrolyte and the sample gas are sufficiently mixed. The sample gas is humidified and further homogenized due to turbulent flow in the chamber formed between the partition plates provided in a position where it is not immersed in the electrolyte. The contact is extremely stable. Therefore, it is clear that the electrode current is stable and the response speed is long. Note that the shapes of the pongee hole plate and the partition plate are not limited to the above embodiments.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of an oxygen analyzer equipped with a pore plate and a partition plate, Figure 2 is a graph showing the time and amount of oxygen present when sample gas is blown into a conventional oxygen analyzer, Figure 3 is a similar graph for an oxygen analyzer of the present invention equipped with a hole plate, and FIG. 4 is a similar graph for an oxygen analyzer equipped with a hole plate and a partition plate. 1... Galvanic cell main body, 2... Sample gas inlet, 3... Porous humidifying tube, 4...
... Pore plate, 5 ... Partition plate, 6 ... Chamber, 7 ... Spiral cathode, 8 ... Anode, 9
...Indicator, 10...Gas exhaust port. Figure l Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] 1. In an oxygen analyzer using a galvanic cell, an electrode whose lower end is immersed in the electrolyte is provided between an anode immersed in an electrolyte and a cathode not immersed in the electrolyte. A porous humidifying tube made of an active material is provided, a pore plate is provided at a position immersed in the electrolyte in the porous humidifying tube, and the sample gas is mixed and humidified with the electrolyte in the porous tube to homogenize the sample gas. An oxygen analyzer characterized by: 2. In an oxygen analyzer using a galvanic cell, a porous humidifier made of an inert material whose lower end is immersed in the electrolyte is placed between an anode immersed in an electrolyte and a cathode not immersed in the electrolyte. A tube is provided, two or more partition plates having small holes are provided at positions that are not immersed in the electrolyte in the porous humidifying tube, and are spaced apart from each other, and the sample gas is mixed and humidified with the electrolyte in the porous tube. An oxygen analyzer characterized in that the sample gas is homogenized. 3. The oxygen analyzer according to claim 2, further comprising a pore plate provided in the porous humidifying tube at a position where the tube is immersed in the electrolytic solution.