阅读说明：本技术 一种具有耐高温搪瓷保护层的热电偶 (Thermocouple with high-temperature resistant enamel protective layer ) 是由 许涛 王奇才 汤永波 于 2020-05-28 设计创作，主要内容包括：本发明公开了一种具有耐高温搪瓷保护层的热电偶,包括铠装热电偶和在铠装热电偶外表面的搪瓷保护层,搪瓷保护层包括如下重量百分比的搪瓷釉料：二氧化硅28％～62％、氧化铝0～13％、氧化钙0～12％、氧化硼0～16％、氧化钠0～17％。本发明通过对搪瓷保护层的合理成分和技术设计,获得了一系列耐高温、抗氧化性能强的、耐酸耐碱的、能够适应多种环境的、且体积轻便的、反应迅速的热电偶产品。通过与现有的热电偶进行比较,能够极大的提高热电偶的使用寿命和性价比。(The invention discloses a thermocouple with a high-temperature resistant enamel protection layer, which comprises an armored thermocouple and an enamel protection layer on the outer surface of the armored thermocouple, wherein the enamel protection layer comprises the following enamel glaze materials in percentage by weight: 28-62% of silicon dioxide, 0-13% of aluminum oxide, 0-12% of calcium oxide, 0-16% of boron oxide and 0-17% of sodium oxide. Through reasonable components and technical design of the enamel protective layer, a series of thermocouple products which are high temperature resistant, strong in oxidation resistance, acid resistant, alkali resistant, capable of adapting to various environments, light in volume and fast in reaction are obtained. Compared with the existing thermocouple, the service life and cost performance of the thermocouple can be greatly improved.)

1. A thermocouple with a high-temperature resistant enamel protection layer is characterized by comprising an armored thermocouple and an enamel protection layer on the outer surface of the armored thermocouple, wherein the enamel protection layer comprises the following enamel glaze materials in percentage by weight: 28-62% of silicon dioxide, 0-13% of aluminum oxide, 0-12% of calcium oxide, 0-16% of boron oxide and 0-17% of sodium oxide.

2. The thermocouple with the high-temperature resistant enamel protection layer according to claim 1, wherein the thickness of the enamel protection layer is 15-650 μm.

3. The thermocouple with the high-temperature resistant enamel protection layer as claimed in claim 1, wherein the sintering temperature of the enamel protection layer is 673-1473K.

4. The thermocouple with the high temperature resistant enamel protection layer as claimed in claim 1, further comprising at least one protection structure.

5. Thermocouple with a high-temperature-resistant enamel covering according to claim 4, characterized in that the protective structure comprises a first protective structure at the outer surface of the enamel covering and/or a second protective structure between the armoured thermocouple and the enamel covering.

6. The thermocouple with the high-temperature resistant enamel protection layer as claimed in claim 1, wherein the armored thermocouple has a diameter of not less than 3 mm.

Technical Field

The invention relates to the technical field of thermocouples for industrial temperature measurement, in particular to a thermocouple with a high-temperature resistant enamel protective layer.

Background

The armored thermocouple is formed by integrally drawing a thermocouple core, insulating magnesium oxide powder and a protective shell for multiple times. In recent years, the armored thermocouple sensor is widely applied to industrial and scientific research by virtue of the characteristics of small thermal inertia, low cost, high stability and the like.

However, in the actual high temperature measurement process of metallurgy, chemical industry, electric power, nuclear energy, aerospace and the like, the armored thermocouple without the protective layer has the following problems in the use process of different environments: 1. the high temperature resistance and the oxidation resistance are poor: the protective shell of the armored thermocouple is generally thin and is usually made of an iron-based material, so that the protective shell is easily oxidized and damaged in a high-temperature and poor-oxidizing use environment, and the service life of the thermocouple is short; 2. poor corrosion resistance: the armored thermocouple without the protective layer is easy to react and corrode with a medium to be measured (such as Fe formed in high-temperature aluminum liquid) in temperature measurement of some media with stronger corrosivity₂Al₅) Failure is formed; 3. poor acid and alkali resistance: the protective shell made of iron-based materials for the armored thermocouple is easily corroded in acid and alkaline environments and cannot be used.

Therefore, in the actual use process, the assembly type thermocouple with the protective sleeve is used in part of scenes aiming at the above defects of the armored thermocouple, but the following problems are also existed: 1. the volume and the weight are large, the installation and the operation are complicated, and normal production and process equipment is easily interfered in certain use occasions with limited volume; 2. thermocouple response time is slow: because the protective sleeve obstructs the heat transfer process between the temperature sensing element and the medium to be measured, the assembled thermocouple has slow response time compared with an armored thermocouple; 3. poor accuracy: and the thermal resistance of the protective sleeve is poor in accuracy of assembling the thermocouple compared with an armored thermocouple, so that the protective sleeve is not suitable for being applied to some application occasions requiring high temperature measurement precision and high reaction speed.

Meanwhile, some technicians develop protective layers such as metal ceramics, oxide ceramics, electroplated nano coatings and the like on the surface of the armored thermocouple. But still the problem that the cost is high, thermocouple response time is slow, only adapt to some specific environment etc. still can appear in the in-service use process.

Disclosure of Invention

In view of the above, the present invention provides a thermocouple with a high temperature resistant enamel protection layer, so as to solve the above problems in the prior art, and compared with the existing thermocouple, the thermocouple is a thermocouple design scheme with simple structure, convenient manufacture, low cost, excellent use performance, and suitability for various application occasions.

The invention provides a thermocouple with a high-temperature resistant enamel protection layer, which comprises an armored thermocouple and an enamel protection layer on the outer surface of the armored thermocouple, wherein the enamel protection layer comprises the following enamel glaze materials in percentage by weight: 28-62% of silicon dioxide, 0-13% of aluminum oxide, 0-12% of calcium oxide, 0-16% of boron oxide and 0-17% of sodium oxide.

In the thermocouple with the high-temperature resistant enamel protection layer, the thickness of the enamel protection layer is 15-650 mu m.

In the thermocouple with the high-temperature resistant enamel protection layer, the sintering temperature of the enamel protection layer is 673-1473K.

The thermocouple with the high-temperature resistant enamel protection layer further comprises at least one protection structure.

In the thermocouple with the high-temperature resistant enamel cover layer, the protection structure comprises a first protection structure on the outer surface of the enamel cover layer and/or a second protection structure between the armored thermocouple and the enamel cover layer.

In the thermocouple with the high-temperature resistant enamel protection layer, the diameter of the armored thermocouple is not less than 3 mm.

The thermocouple with the high-temperature resistant enamel protection layer provided by the invention applies high-temperature enamel glass to the design of the armored thermocouple protection layer, and solves the production process problems of small diameter, large surface stress, high adhesion difficulty of the enamel protection layer, easy cracking of enamel and the like of the armored thermocouple through reasonable component and parameter design, and obtains the following effects by utilizing excellent use and protection performance of the enamel protection layer compared with the prior art:

(1) high acid and alkali resistance: by applying a coating to the enamel composition (e.g. SiO)₂) Equal reasonable adjustmentIn the whole process, a protective layer with high tolerance to acid environment or alkaline environment can be obtained, and the service life of the armored thermocouple in the acid environment and the alkaline environment is prolonged;

(2) high temperature resistance and oxidation resistance: by adjusting the initial softening temperature of the enamel, the enamel can obtain proper high temperature resistance, and the oxidative denaturation of the thermocouple in the use process is reduced;

(3) the response time is fast: the response time of the enamel armored thermocouple can reach within 1 minute due to the excellent heat-conducting property of the enamel glass component;

(4) the precision is accurate: the thickness of the enamel protective layer is thin, the maximum thickness is not more than 650 mu m, and the precision of the armored thermocouple is hardly influenced;

(5) the appearance is beautiful, and the use is light.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts:

FIG. 1 is a schematic structural diagram of a thermocouple with a high temperature resistant enamel protection layer according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a thermocouple having a high temperature resistant enamel protection layer according to another embodiment of the present invention;

in the figure: 1 is an armored thermocouple, 2 is an enamel protection layer, 3 is a first protection layer, and 4 is a second protection layer.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Exemplary embodiments of the invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

In order to better understand the technical solutions, the technical solutions will be described in detail below with reference to the drawings and the specific embodiments of the specification, and it should be understood that the embodiments and specific features of the embodiments of the present invention are detailed descriptions of the technical solutions of the present application, and are not limited to the technical solutions of the present application, and the technical features of the embodiments and examples of the present invention may be combined with each other without conflict.

The thermocouple with the high-temperature-resistant enamel protection layer comprises an armored thermocouple 1 and an enamel protection layer 2, wherein the enamel protection layer 2 is attached to the outer part of the armored thermocouple, and the main components of enamel protection layer 2 comprise, by weight, 28% -62% of silicon dioxide, 0% -13% of aluminum oxide, 0% -12% of calcium oxide, 0% -16% of boron oxide, 0% -17% of sodium oxide and the like. Further, the thickness t of the enamel protection layer is 15-650 mu m, and the diameter D of the armored thermocouple 1 is not less than 3 mm.

Specifically, in an embodiment according to the present invention, only the enamel protective layer 2 is included on the outer surface of the armored thermocouple 1. In another embodiment according to the present invention, the first protective structure 3 is included outside the armored thermocouple and the enamel protective layer (as shown in fig. 1), and the first protective structure 3 may include one protective layer or a plurality of protective layers, which is not limited by the present invention. The surface of the thermocouple is not adhered to the metal solution during the operation process through the first protection structure. It will be appreciated by those skilled in the art that the first protective structure may be comprised of one or more protective layers selected from the group consisting of a water-based paint protective layer, an alcohol-based paint protective layer, an oil-based paint protective layer, a metal oxide/hydroxide protective layer, a plating protective layer, and the like, and the present invention is not limited thereto. In another embodiment according to the present invention, a second protection structure is further included between the armored thermocouple and the enamel protection layer, and the second protection structure may include one or more protection layers, which is not limited in this respect. The second protection structure improves the adhesive strength of the enamel and improves the flushing resistance of the thermocouple in a medium to be measured. It will be understood by those skilled in the art that the second protective structure may be composed of one or more protective layers selected from a water-based paint protective layer, an alcohol-based paint protective layer, an oil-based paint protective layer, a metal oxide/hydroxide protective layer, a plating protective layer, and the like, and the present invention is not limited thereto. In yet another embodiment of the present invention, a first protective structure 3 (shown in FIG. 2) is included on the outside of the armored thermocouple and enamel cover, while a second protective structure 4 is included between the armored thermocouple and enamel cover. Here, the first protective structure and the second protective structure may include a protective layer or a plurality of protective layers, respectively, which is not limited in the present invention.