Modification and optimization of furnace roll and bottom roll ring of CSP heating furnace
The CSP heating furnace roll is responsible for supporting and driving the slab in the soaking pit. In order to meet the needs of long-term continuous heavy load rotating operation of the furnace roll under high temperature and harsh environmental conditions, the furnace roll is designed as a water-cooled furnace roll, which is mainly composed of metal roll body, heat-resistant metal roll ring, refractory thermal insulation layer, exposed metal roll shaft, etc. The furnace roll is the most important and easily damaged key equipment in the mechanical equipment of the heating furnace, with large online quantity, high price and low service life. In order to solve the problem of spare parts supply of furnace rolls, prolong the service life of furnace rolls, improve the slab temperature uniformity and reduce the cost of enterprises, starting from the structural research of furnace rolls, improve the furnace roll structure, develop a new structure of furnace rolls with good high-temperature performance to replace the existing furnace rolls, and determine the reasonable layout of furnace rolls in the furnace to improve the slab temperature uniformity, which is of great significance to reduce the production cost of the steel plant. Specifically, aiming at the high temperature ablation of the furnace roll ring, the damage of the refractory layer, and the insufficient uniformity of the slab temperature, and taking improving the high temperature performance of the furnace roll and the uniformity of the slab surface temperature as the starting point, the distribution and layout characteristics of the furnace roll in the furnace and the radiation heat transfer characteristics are analyzed, and the finite element numerical simulation method is used to calculate the temperature and stress distribution of the furnace roll in the furnace and the influence of the furnace roll layout on the slab surface temperature uniformity, It provides a basis for improving the structure of furnace roll performance and slab temperature uniformity.
The main research contents of this paper are as follows: 1) A fluid solid coupled heat transfer model of furnace roll is established to calculate the temperature distribution of furnace roll under high temperature furnace gas. The radiation heat transfer of the furnace roll in its interior is analyzed, the heat absorption capacity of the outer surface of the furnace roll is obtained, and the temperature field distribution of the domestic furnace roll under the furnace gas of different temperatures is calculated. The calculated data are compared with the on-site monitoring, which proves the reliability of the simulation model of the water-cooled furnace roll. The maximum temperature of the furnace roll ring working face at 1300 ℃ has exceeded the limit service temperature of its material, and the furnace roll structure needs to be improved. 2) According to the structural characteristics of the furnace roll, the furnace roll is divided into roller shaft - roller ring substructure and roller shaft - anchor - refractory layer substructure for thermal stress calculation; The temperature distribution obtained from the temperature field simulation analysis is taken as the thermal boundary condition, and the structural constraints are imposed to calculate the thermal stress. The stress distribution of each part is obtained to provide data support for the improvement of the furnace roll structure. 3) In view of the insufficient cooling of the roll ring and the unreasonable structure of the anchor in the existing furnace roll temperature and stress field simulation, the cooling structure, roll ring structure and anchor structure of the furnace roll are improved respectively, and a furnace roll structure with direct cooling roll ring, V-shaped and double V-shaped anchor staggered and anchored is designed. The improved structure is simulated, and compared with the calculation and simulation results before and after the improvement, the improved structure can improve the high temperature performance of the furnace roll. 4) The temperature field in the heating process of slab transported by furnace roll is simulated to realize the analysis of influencing factors on slab temperature uniformity; In order to improve the uniformity, the slab surface temperature under different arrangement of furnace rollers is analyzed, and the optimal arrangement of furnace rollers with improved structure in the furnace is determined; In the case of typical rolling accident, determine the soaking time of slab in the furnace to be increased to meet the process requirements of slab temperature uniformity. Based on the structure of the furnace roll, this paper analyzes the influence of different structures on the temperature field and stress field of the furnace roll through numerical simulation, and the influence of different arrangement forms of the furnace roll on the slab uniformity, which has guiding significance for the structure improvement and arrangement of the furnace roll.
In CSP heating furnace, the roll ring is in direct contact with the slab. Therefore, the position, shape, material and performance of the roll ring have an important impact on the force on the furnace roll and the slab surface quality. At present, the main problems of CSP heating furnace furnace bottom roll ring are that the roll ring falls off quickly, burns, crusts, and rolls, causing the furnace roll and furnace bottom roll to bear uneven force and bend, and the pressed iron oxide scale on the slab surface, deviation, etc. will cause the surface quality and shape problems of hot rolled sheet, especially on the cold rolled base material. Therefore, under the requirements of implementing the consistent quality system, It is very necessary to reform and optimize the furnace roll ring.
CSP series water-cooled roll professional manufacturer has more than 20 years of professional manufacturing experience. CSP series water-cooled roll can be customized as required. Sinking roll and CSP series water-cooled roll are reliable in quality, reasonable in price and perfect in service
In view of the problems such as cracking and damage of CSP water-cooled furnace roll in a short period of time, the heat-insulating and fire-resistant castable for CSP furnace roll was prepared by using silica sol modified light mullite as the main aggregate, adding an appropriate amount of expansion additives and sintering agents, selecting cement, activated silica micro powder and alumina micro powder as the composite binder, and adding an appropriate amount of zirconium containing fire-resistant fiber to improve the toughening effect The physical property test and scanning electron microscope analysis showed that the silica sol immersion modification effectively improved the strength of lightweight aggregate, and enhanced the compactness of aggregate and matrix. The strengthening mechanism was studied The actual production application shows that the developed refractory castable has high strength, light volume weight and excellent thermal insulation performance. It has been successfully applied to the water-cooled furnace roll of CSP heating furnace. The service life of the thermal insulation lining has been extended from an average of 8 months to more than 18 months.