On 2018-08-08 14:48:54
vacuum annealing furnace development prospect
With the development of science and technology and the efforts of the majority of engineering and technical personnel, the annealing furnace day tends to the direction of high-yield and energy-saving development, the furnace structure is more compact and reasonable, the annealing process is becoming more perfect, and the annealing quality is constantly improving, which meets the different needs of users.
Development of vacuum annealing furnace
The recrystallization annealing temperature of metal is related to the deformation degree, chemical composition, heating speed, original metallographic structure and other factors during cold rolling. How to complete the recrystallization annealing in the production line can meet the recrystallization temperature requirements of each steel in different ways in production practice. However, it is the most effective way to change the heating and cooling time of strip in annealing furnace. In order to facilitate the operation and reduce the artificial interference, the annealing process chart and the annealing process curve should be drawn up to give full play to the guiding role of the annealing process curve in the production practice.
The control system realizes fully computerized operation of the continuous annealing furnace of modern hot dip galvanizing unit, including furnace tension control, plate shape control, deviation control, combustion control, temperature control, furnace pressure control, etc. The control system shall realize the following functions: adjust the executive system according to the field instrument detection; logic control of fan start and stop program, safety monitoring of gas system and water cooling system, burner ignition and other logic control; display and record of operation parameters, medium consumption and production statistics; communication between the upper computer display system and the operator; setting program and operator designation Mathematical model calculation of dynamic control and logical control of accident and production report; contact and exchange information with process computer. Connect field instruments to exchange digital and analog signals. According to the actual situation of strip steel and the target heating system, the set value of furnace parameters is automatically determined by mathematical model. The realization of the above control functions can give full play to the maximum effect of the furnace and reduce the unit consumption of the annealing furnace.
Although the combustion supporting air of the annealing furnace has been preheated to realize the comprehensive utilization of energy, due to the limitations of the material, pipe network and control elements of the conventional preheater, the air temperature cannot be effectively improved, and the flue gas emission temperature is still very high. Due to the low combustion efficiency of common radiant tube, the temperature of flue gas emission causes a lot of heat loss. In order to fully recover and utilize the waste heat of flue gas and realize the comprehensive utilization of energy, the following measures can be taken: install waste heat boiler in the flue of PHS section and the waste gas pipeline of rth section, these waste heat boilers are used to produce saturated steam, and the steam produced can be used as the heating and drying medium and heat source of galvanizing and other units.
With the improvement of the quality requirements of galvanized sheet and the expansion of the use of galvanized sheet, flameless heating will gradually replace the flamed heating. At present, 6 continuous annealing furnaces for hot galvanizing have been built in China, including 6 under construction. At present, in the metallurgical industry, regenerative combustion technology has been comprehensively promoted and applied, especially the newly built and rebuilt heating furnaces have all been built into regenerative heating furnaces. The application of regenerative combustion technology in continuous annealing furnace is the main development direction of heat treatment furnace in the future.
At present, the annealing furnace is gradually developing from horizontal to vertical. However, due to the advantages of low investment and convenient construction, people are constantly improving the horizontal annealing furnace, such as shortening the furnace length, adopting high-temperature annealing, high-efficiency heating and cooling, unsupported furnace roll, high-efficiency alloying and other measures to improve the annealing quality and production of strip steel Quantity. By optimizing the technological process and reasonable configuration, the faults can be reduced and the productivity can be increased.