JPS6367853B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a solid electrolyte oxygen meter.

There are various types of solid electrolyte oxygen meters in practical use, but among them, direct insertion oxygen meters do not require a sampling device, so they have good response and are less likely to cause troubles due to dust or condensate. It has many advantages and has been attracting attention recently.

FIG. 1 is an explanatory diagram of the configuration of a detection section in a conventional oxygen meter of this type. In the figure, 21 is a probe installed on the furnace wall 23 by a flange 22 attached to the body by insert welding, and 24 is a test tube-shaped solid electrolyte made of zirconia, ceria, thoria, or the like. The solid electrolyte 24 is installed with the closed end facing the tip side of the probe 1, and forms a wall separating the tip side and the non-tip side of the probe 1. 2
Reference numerals 5 and 26 designate electrodes that are closely installed inside and outside the walls of the solid electrolyte, 27 a temperature sensor that detects the temperature of the solid electrolyte, and 28 a heater that heats the solid electrolyte. A temperature control system is configured by a temperature sensor 27, a heater 28, and a controller (not shown), and the solid electrolyte 24 is maintained at a predetermined temperature.
A signal corresponding to the difference in oxygen concentration between the inside and outside of the wall is transmitted via electrodes 25, 26 and lead wires (not shown). 29 is a filter for preventing dust from adhering to the wall surface of the solid electrolyte 24; 30 has one end located at the closed end (outside) of the solid electrolyte 24, and the other end located on the non-tip side of the probe 1; This is a conduit that introduces the solid electrolyte into the closed end of the solid electrolyte 24.

By the way, in this type of oxygen meter, it is necessary to occasionally replace the solid electrolyte 24 in order to maintain measurement accuracy. However, as described above, the conventional detection section has a complicated structure with various parts installed at the tip of the probe 1, making the replacement work cumbersome.

The present invention has been made in view of the above, and an object of the present invention is to provide a cell unit consisting of a test tube solid electrolyte and a flange integrated with the test tube solid electrolyte at its closed end in order to easily replace the solid electrolyte. To provide a solid electrolyte oxygen meter having a configuration in which the probe is inserted and fixed from the tip of the probe first, and the calibration gas introduction pipe can be easily separated.

The present invention, which has achieved the above object, includes a conduit installed in the probe with one end located near the tip of the probe and the other end protruding toward the non-tip side of the probe, a test tube-shaped solid electrolyte, and the solid electrolyte. It consists of a flange that is integrated with a cell unit that is installed in the probe by inserting the closed end of the solid electrolyte from the tip of the probe, and a cell unit that has one end inserted into the hollow part of the solid electrolyte and the other end located near the tip of the probe. It consists of a generally U-shaped conduit connected to the conduit, and a flange that supports the conduit and is joined to the flange of the cell unit, and fixes the cell unit to the tip of the probe by means of a fastening tool.

The present invention will be described below with reference to the drawings.

2 and 3 are explanatory diagrams of the configuration of an oxygen meter according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of the main part of the detection section, and FIG. 3 is an enlarged explanation of a part of the main part. It is a diagram.

In each figure, 1 is a probe installed on the furnace wall 3 by a flange 2 attached to the body by insert welding, 4 is a test tube-shaped zirconia 5 and a flange 6, and the probe 1 is attached to the tip of the probe 1. The installed cell unit 7 is a heater that heats the zirconia 5. Although not shown, zirconia 5
A platinum porous electrode film is formed on both sides of the tip (bottom of the test tube), and these electrodes create two chambers (inside and outside of probe 1) formed by walls of zirconia 3.
A signal corresponding to the difference in oxygen concentration is detected and output to the outside via a lead wire.
Further, a temperature sensor is installed at the tip of the zirconia 5, and the zirconia 5 is controlled to a predetermined temperature by a temperature control system consisting of this sensor, an adjustment section, and a heater 7. .

8 is a conduit consisting of a straight pipe 8a and a U-shaped portion 8b, 9 is a mesh filter installed at the open end of zirconia 5, and 10 is a flange. The flange 10 connects the U-shaped portion 8b of the conduit 8 to the bracket 1.
1 to support the cell unit 4 through the probe 1, and to fix the cell unit 4 to the tip of the probe 1 using a bolt 12. In this fixed state, the U of the pipe line 8
One end of the letter-shaped portion 8b is located in the hollow portion of the zirconia 5, and the other end is connected to one end of the straight pipe portion 8a of the conduit 8. Reference numeral 13 designates a partition plate that partitions the interior of the probe 1 chamber into upper and lower sections except for the vicinity of the zirconia 5, and 14 designates a bottomed cylindrical lid installed at the non-tip portion of the probe 1. The lid 14 is the partition plate 1
Each chamber of the probe 1 formed by the probe 3 is individually and independently communicated with the outside air.

In the detection section of the oxygen meter described above, during measurement, the tip of the probe 1 is in the flow of the measurement gas at 200 to 500°C, and the measurement gas enters the zirconia 5 through the filter 10 by diffusion and convection. It is always in contact with the inner wall of zirconia 5. On the other hand, zirconia 5
The gas in contact with the outer wall of the probe 1, that is, the air inside the probe 1, is heated by the heat of the measurement gas, heater 7, etc. and reaches a high temperature (700°C to 850°C). , atmosphere → chamber below probe 1 → tip of probe 1 (near zirconia 5)
→Chamber above probe 1→Atmospheric convection is formed. Therefore, the reference gas side of the zirconia 5 is always replaced with fresh air, and a stable output signal can be obtained. Incidentally, at the time of the above measurement, the pipe line 8 is normally in a sealed state, and the gas within the pipe line 8 does not flow. Therefore, the presence of the conduit 8 has no effect on the flow or composition of the measurement gas flowing into the zirconia 5, but the conduit 8 can be used to speed up the response. That is, by connecting one end of the conduit 8 to an inlet of an ejector or the like, the flow of the measurement gas into the zirconia 5 is accelerated and the gas replacement is accelerated.

Next, the calibration operation and cleaning operation will be explained.

Calibration is performed while a calibration gas having a slightly higher pressure than the measurement gas is introduced into the zirconia 5 through the pipe 8 while the measurement state is maintained. Since the calibration gas has a higher pressure than the measurement gas, the two gases are smoothly replaced within the zirconia 5, allowing accurate calibration.

If a large amount of cleaning gas, such as instrumentation air, is flowed in place of the above-mentioned calibration gas, dust adhering to the filter 10 and the zirconia 5 can be removed by blowback.

On the other hand, to replace the zirconia 5, the bolts 12 are unscrewed, and the straight pipe part 8a and the U-shaped part 8 of the conduit 8 are replaced.
b is separated and the cell unit 4 is pulled out from the tip of the probe 1. Therefore, the replacement work can be easily performed.

As explained above, according to the solid electrolyte oxygen meter of the present invention, a cell unit consisting of a test tube solid electrolyte and a flange integrated therein is fixed by further inserting the tip of the probe with its closed end first. Furthermore, the calibration gas introduction line can be separated near the tip of the probe, making the maintenance work of replacing the solid electrolyte extremely easy.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the configuration of a detection section of a conventional solid electrolyte oxygen meter, FIG. 2 is an explanatory diagram of the configuration of a detection section of a solid electrolyte oxygen meter according to an embodiment of the present invention, and FIG. 3 is an explanatory diagram of the configuration of a detection section of a solid electrolyte oxygen meter according to an embodiment of the present invention. FIG. 2 is an enlarged explanatory view of a main part of a detection section of a solid electrolyte oxygen meter according to an embodiment. DESCRIPTION OF SYMBOLS 1...Probe, 4...Cell unit, 5...Test tube solid electrolyte, 6...Flange, 7...Heater, 8...
Pipe line, 8a... Straight pipe part of the pipe line, 8b... U-shaped part of the pipe line, 9... Mesh filter, 10... Flange,
11... Bracket, 12... Bolt, 13... Partition plate.

Claims (1)

[Scope of Claims] 1. A solid electrolyte oxygen meter that has a partition made of a solid electrolyte at or near the tip of the probe and detects a signal corresponding to the difference in oxygen concentration between the inside and outside of the probe. , a conduit installed in the probe with one end located near the tip of the probe and the other end protruding toward the non-tip side of the probe, a test tube-shaped solid electrolyte, and a flange integrated with the solid electrolyte. a cell unit that is installed in the probe by inserting the closed end of the solid electrolyte from the tip of the probe;
A substantially U-shaped conduit whose one end is inserted into the hollow part of the solid electrolyte and whose other end is connected to a conduit located near the tip of the probe; A solid electrolyte oxygen meter comprising: a flange for fixing the cell unit to the tip of the probe with a tightening tool.