JPS61198047A - Structure for insertion type oxigen detector - Google Patents

Abstract

PURPOSE:To improve the durability by covering a copper wire with a heat resisting and corrosion-resistant metal, with regard to a signal conductor and a heater conductor in an insertion type oxygen detector which is inserted into a measuring gas and measures an oxygen density. CONSTITUTION:An insertion type oxygen detector is constituted by placing a heater bobbin 4, a heating element 5 and a thermocouple 6 through ceramics supporting bodies 2, 3 in a probe case 1, and also holding an fixing an oxygen detecting element 9 by a cap 10 and containing it in the end part. In this case, a conductor 7 from the detecting element 9 and the thermocouple 6 is formed by inserting a copper wire 15 into a heat resisting and corrosion-resistant metallic pipe 14 of stainless steel, etc., and sealing both ends, and also a heater conductor 8 is also formed by inserting a copper wire 12 into a heat resisting and corrosion-resistant metallic pipe 13 and sealing it. Accordingly, a sufficient heat and corrosion resisting property is obtained at a low cost without using a platinum wire, etc., and also a titled detector can be made small in size and light in weight by a simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an oxygen detector structure for measuring oxygen concentration by inserting a probe into a sample gas.

Currently, in various industrial fields such as steel and ceramics, cement, petrochemical and electronic materials, it is necessary to measure the oxygen concentration in various gases. For example, heating furnace, soaking furnace, annealing furnace,
Typical examples include combustion exhaust gas from carburizing furnaces, incinerators, etc. Measuring oxygen concentration and controlling combustion in these combustion applications is extremely important from an economical and pollution prevention perspective. Measurement of oxygen concentration is also indispensable in industrial growth control, residential environment management, biochemistry, medical fields, etc.

Among these, an insertion type oxygen detector is advantageous in terms of responsiveness and reliability when controlling the oxygen concentration in the measurement gas.

[Conventional technology]

General insertion type oxygen detector structure: 2. Platinum wire is used for the high temperature part as the lead wire for the element signal.

Therefore, the cost is extremely high.

Heater built-in structure 6: In some cases, it is difficult to avoid heat corrosion of the heater wires, but a raft structure has been proposed as a countermeasure. A method of pulling out a long heater wire and connecting it to the copper wire at a place where the temperature is slightly lower than that of the heater.
or.

Insulators, etc. (There is a method of using thick copper wire in anticipation of heat corrosion when setting up a two-layer wooden terminal, but it is difficult to make it smaller and lighter. Both methods can be used for a certain period of time, but 1
Corrosion of copper wires due to heat rather than essential countermeasures is unavoidable and causes trouble.

There is also a method of using heat-corrosion resistant stainless steel wire, but the electrical resistance of stainless steel is approximately 50 times greater than that of copper, so it must be made considerably thicker in order to be used as a conductor, which is not practical.

[Problem that the invention seeks to solve]

Conventional insert-type oxygen detector structures have several drawbacks.

f inside the rope (- The installed elements, signal conductors, and heater conductors are corroded by the heat of the measurement exhaust gas and the heat C2 of the heater, resulting in increased resistance of the conductors, poor contact, or even disconnection. This causes inconvenience and there is a problem with the durability of the conductor.

Insulating materials are often used to protect the conductors from heat sources, making the structure complex and large.

Platinum wire is used as the signal lead wire of the element, but it is expensive and it is not possible to use a thick wire with sufficient strength. As a result, sufficient care must be taken to fix the element as there is a risk of element rattling and vibration (there is a risk of wire breakage).As a result, not only is reliability insufficient, but the structure is also larger and more complex.

The purpose of the present invention is to provide a structure for an insertion-type oxygen detector that is small and lightweight and can be stably used for a long period of time, using heat-resistant corrosion-resistant conductors for element signal lead wires and heater wires in order to solve these conventional drawbacks. It is something to do.

[Means for solving problems]

In the structure of the insertion type oxygen detector of the present invention, in which the element and the heating device are housed in the probe, the element signal conductor and the heater conductor are coated with a heat-resistant and corrosion-resistant copper wire, that is, stainless steel, which is heat-resistant and corrosion-resistant. It is characterized by the use of a conductor wire that combines the two properties of copper and copper as good electrical conductors, and has low electrical resistance and excellent heat and corrosion resistance.

〔Example〕

More details will be explained based on the embodiments of the present invention shown in the drawings.

In the glove case 1, there is a ceramic insulating support 2.3.
A heater fixed to the heater is composed of a heater 4, a heating element 5, a thermocouple 6, an element signal conductor 7°, and a heater conductor 8. The element 9 is inserted into the heater from the tip of the prosthesis, and is held and fixed with a cap 10 and a cooker material 11.

The heater wire 8 is made by passing a copper wire 12 through a heat-resistant, corrosion-resistant metal tube 131, such as 5US310S or Inconel, and joining the heater wire. At this time, seal the joint by welding or brazing to prevent air from entering the limb canal. At the other end, the joint between the limb tube and the copper wire is similarly sealed.

Similarly, for the signal conductor 7, a copper wire 15 is inserted into a heat-resistant and corrosion-resistant metal tube 14, and both ends are sealed. Then, it is connected to a platinum printed wire 16 drawn out from the element 9.

〔Effect of the invention〕

The insertion type oxygen detector structure of the present invention is as described above,
The conductor structure has an extremely simple structure in which the steel wire is covered and protected with heat-resistant metal, making it possible to reduce the size and weight, and improve heat corrosion resistance without impairing electrical properties, so it can last for a long time. Can be used stably.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view showing an embodiment of the present invention. 7...Element signal conductor wire, 8...Heater conductor wire, 12°14...Copper wire, 13.15...Heat-resistant metal tube.

Claims (1)

[Claims] In the insertion type oxygen detector structure, which measures the oxygen concentration by inserting the oxygen detector into the sample gas, the oxygen detection element, the signal conductor wire, and the heater conductor wire are protected by coating the copper wire with a heat-resistant metal. An insertion type oxygen detector structure characterized by a conductor.