Correct selection of wear-resistant thermocouple in cement metallurgy industry
In view of the temperature measurement characteristics of the three-stage cylinder, four-stage cylinder and five-stage cylinder cone temperature of the cement dry process rotary kiln production line, the temperature in the middle of the calciner, the kiln tail smoke and the kiln head cover, the ordinary wear-resistant thermocouple can not meet the special temperature measurement conditions of high temperature resistance and erosion resistance due to the material of the protective tube, resulting in short service life of the thermocouple, increased condition funds, frequent product replacement, no guarantee of transmission signal and long-term warning of the instrument, At the same time, it increases a lot of workload for instrument maintenance. This phenomenon is a common problem in the national cement industry.
After a number of textual research and research, combined with the characteristics of foreign cement production technology, the advent of special wear-resistant thermocouple in cement plant has not only solved a major problem of wear-resistant temperature measurement control in cement industry, but also brought considerable economic benefits to all users.
The special wear-resistant thermocouple for cement plant is mainly composed of junction box, junction tube, special protective tube, insulating sleeve, wiring terminal, special lining sleeve and Thermoelectrode. It is equipped with various installation components. The integrated temperature transmitter can be selected in the optional accessories.
The wall thickness of the special wear-resistant thermocouple protection tube for cement plant is generally 4-8mm (determined according to the temperature measurement site). The protective pipe is specially designed for the cement plant, and its function is to prolong the service life of thermocouples at the temperature measuring points of C3, C4, C5, calciner, tertiary air duct, kiln tail smoke and kiln head cover. When installing the product, according to the different industrial measurement and control points, leave blank or protective tube on the kiln in advance, and select the special thermocouple of corresponding specification.
In the design process of the product, the specifications and models installed in the running 1000-10000t / d cement production line are fully considered for use at each measurement and control point of the production line.
Selection of protective tube length: insertion depth in furnace + thickness of furnace wall + exposed part outside furnace = total length.
During the production and operation, when installing or replacing the thermocouple, please put the thermocouple into the furnace slowly and fix the connecting device.
When the long-term temperature measurement of the process measurement and control point is at 1100 ℃, the thermocouple works normally for about 60 working days. Due to the long-term high temperature state of the thermocouple wire, its accuracy will change slightly. The temperature measuring element of the thermocouple can be replaced according to the requirements of the process.
Where blanking or scouring is involved, the thermocouple shall be turned over and reinstalled at 90 ℃ after 60 working days of use, so as to double the service life of the special wear-resistant thermocouple.