保护管材料的选用采用氮化硅结合碳化硅工艺，具有良好的导热性、抗热振性和耐磨性，抗冲刷，无污染，最高使用高温达1450℃，广泛用于铝液、铜液、锌液等有色金属液体的测温和加热保护。 The selection of wear-resistant thermocouple protection tube material adopts silicon nitride and silicon carbide process, which has good thermal conductivity, thermal shock resistance and wear resistance, erosion resistance, no pollution, the highest use temperature is up to 1450 ℃, widely used in aluminum Temperature, heating and protection of non-ferrous metal liquids such as liquid, copper and zinc. Such as chemical plants, smelting plants, power plants, cement plants, etc., ordinary thermocouples, thermal resistance can easily damage. Therefore, a wear-resistant thermocouple (resistance) must be used in these cases. The thermocouple (resistance) is especially suitable for the temperature measurement of sulfurized bed, coal mill export, primary and secondary coal and cement industries.
I. Instructions for use
主要由接线盒、接线管、专用保护管、绝缘套管、接线端子、专用内衬套管、热电极组成基本结构，并配有各种安装组件，在选配件中同时可选一体化温度变送器。 AOTS series metal silicon carbide (recrystallized) wear-resistant thermocouples are mainly composed of junction boxes, junction tubes, special protection tubes, insulation sleeves, terminal blocks, special lined sleeves and thermal electrodes, and are equipped with various installations. Component, and optional integrated temperature transmitter in optional accessories.
AOTS series metal silicon carbide (recrystallized) thermocouple protection tube generally has a wall thickness of 4-8 mm (determined according to the temperature measurement location). This protection tube is specially designed for cement plants, and its role is to extend the service life of thermocouples at the temperature measurement points of C3, C4, C5, decomposition furnace, tertiary air duct, kiln tail smoke, and kiln head cover.
When installing this product, you can leave empty or protective tubes on the kiln in advance according to the different industrial measurement and control points, and select the dedicated thermocouple of the corresponding specification.
In the design of this product, we have fully considered the specifications and models installed in the running 1000-10000T / D cement production line for use at various measurement and control points on your production line.
Selection of protective tube length: depth of furnace insertion + wall thickness + exposed part of the furnace = total length
During the production operation, when installing or replacing the thermocouple, slowly insert the thermocouple into the furnace and fix the connection device.
When the long-term temperature measurement at the process measurement and control point is at 1100 ° C, the K-type thermocouple works normally for about 60 working days. Due to the long-term high temperature of the wire, its accuracy will change slightly. The thermocouple can be replaced according to the requirements of the process Temperature measuring element. In the place where the blanking or scouring is involved, after the thermocouple is used for 60 working days, the thermocouple is turned over and reinstalled at 90 ° C, so that the life of the special wear-resistant thermocouple is doubled.
Improved thermocouple protection sleeve to extend the life of the thermocouple
The long-life thermocouple for measuring the temperature of corrosive media is an improvement on the existing thermocouples. The positive and negative electrodes of its thermocouple wire are respectively housed in a segmented insulated ceramic tube, and the two protective tubes are sheathed, that is, the inner layer is resistant to high temperatures. The white corundum protection tube and outer titanium protection tube have an improved long-life thermocouple life of one year or more, which is 15-20 times longer than the existing single-protection tube thermocouple, reducing frequent replacement. The troublesome and dangerous operation of temperature measuring thermocouples has great economic value and social benefits.
Measure the temperature of long-life thermocouples in the corrosive medium. The positive and negative electrodes of the thermocouple wire 5 are sheathed in the segmented insulated ceramic tube 4, respectively. The working ends of the thermocouple wire 4 are welded together. The positive and negative ends of the terminal are respectively connected to the terminal 6 in the terminal box housing 3, and the galvanic wire 5 and the insulating porcelain tube 4 cover the protective tube. The hot end of the protective tube is closed, and the cold end is connected to the terminal box housing 3. The end cap 9 is screwed to the junction box housing 3 through a threaded opening. It is characterized by two protective tubes, namely the galvanic wire 5 and the insulating porcelain tube 4. The inner protective tube is a high-temperature-resistant white corundum protective tube 2 and the outer protective tube. It is a titanium protection tube 1.
Thermocouples, as contact temperature measuring instruments, have the advantages of simplicity, accuracy, reliability, and low price. In the usual temperature measurement field, the use of outer casings such as stainless steel tubes or high aluminum tubes can meet production requirements, but because the aluminum liquid has strong corrosiveness, permeability, easy nodulation, and easy slagging, the service life of the thermocouple is greatly increased. shorten. Our aluminum alloy die-casting furnace has a working temperature of 680 ° C ± 20 ° C. Previously, thermocouples were made of stainless steel as a protective tube. Generally, about 10 Od needed to be replaced. If this continues, the economic loss will be astonishing.
To reduce production costs, we made improvements. The solution is to use double-layer protection for the thermocouple with stainless steel tube inside and SiC tube outside. Because SiC pipe has good properties such as good oxidation resistance, corrosion resistance, penetration resistance, thermal shock resistance, no nodulation and so on. The outer sleeve is fixed on the inner sleeve by three screws. When the outer sleeve is about to be used up, replace it with a new one, which greatly extends the service life of the thermocouple.
Practice shows that the effects of installing a protective tube are quite different: (1) The service life of a thermocouple is extended from about 10 d to about 3 months. Reduced economic losses; (2) no need to frequently replace the instrument once, improving work efficiency.
With the continuous improvement of automation, temperature measurement involves various fields of the national economy, such as industrial and agricultural production, national defense, scientific research, medical treatment, health, environmental protection, meteorology and aerospace. Thermocouples have become the most widely used temperature sensing elements in the fields of industrial production and scientific research due to their advantages such as stable performance, accuracy and reliability, simple structure, convenient use, wide temperature measurement range, and remote signal transmission. The long-term stability and service life of the thermocouple are closely related to the protection tube. According to relevant data statistics, the thermocouple's damage rate in the normal measurement range directly depends on the excellent performance of the protective tube material. 使用寿命的前提。 Therefore, the correct choice of protective tube in actual use is a prerequisite to extend the service life of wear-resistant thermocouples .