THERMAL-CONDUCTIVITY MEASUREMENTS FOR FILLING MATERIALS FOR SLIDING GATES AND THEIR EFFECTS ON FREE- TAPPING PERFORMANCE OF STEEL LADLE

The thermal conductivities of different typical species filling materials for sliding gate systems for steel ladles were measured using a hot wire technique, and the relationships between thermal conductivity and temperature were regressed. The factors affecting thermal conductivity were analyzed by using variance analysis for a perpendicular experiment. The effects of thermal conductivity on sliding gate free tapping were studied, and it was revealed that decreasing the thermal conductivity of the filling materials is beneficial in enhancing the rate of free tapping for sliding gates.

Brief of the technology using sliding gate for slag stopping during converter tapping in the steelmaking plant of Baoshan Iron & Steel Co.,Ltd.

The sliding gate used to stop slag during converter tapping is similar to the control of slide gate in ladle,with the sliding gate device installed outside the BOF tapping hole tip.Owing to the quick opening and closing(in 0.5 s) of the sliding gate,it can not only effectively stop the pre - slag and post - slag during converter tapping but also automatically judge and stop slag with the help of AMEPA slag detecting and PLC control technology.Currently it is regarded as the best process to stop slag during converter tapping.

Influence of the Trends Robotics and Digitalisation on Ladle Slide Gate Development

The article focuses on the influence of operator and process safety and the trends of robotics and digitalisation on a ladle slide gate that was introduced to the market 6 years ago[1].After more than 50 installations,customer experience was gathered and new features were added to a system upgrade.These upgrades are related to safety,ease of operation,and low operational costs.Especially a newly introduced“open check”feature increases the confidence level of the operators and can boost performance.With growing requirements to increase safety for people and processes in the ladle preparation area and on the continuous casting floor,automation has become increasingly important in steel plants.A slide gate prototype is currently underway to launch an innovative new gate design striving for full automation.Several critical process steps are already available and successfully used in the steel plants,such as cylinder connection,slag detection integration,and ladle gate preparation area automation.Fully automated operation will be followed by digitalisation,allowing for tracking of performance,safety,and quality.This paper summarises new features available for slide gates and outlines individual initiatives towards fully automated operation and data acquisition examples of digitalisation.

Enhanced clean steel tapping on BOF vessels with the interstop converter gate type CG series

Trends in today' s steel production show increasing demands for highly-sophisticated steel grades. Therefore,the steel industry will eventually be required to install best performing technologies to meet governmental specifications designed to significantly reduce environmental emissions.Such efforts are supported by innovative new solutions in the entire steel making process.One process that will need to be addressed is the cleanliness of the steel in the liquid steel phase,especially during the BOF-tapping process. The new converter gate(CG)(Fig.1) best supports the slide gate tapping technology for converters in terms of clean steel,productivity,yield and availability-at reduced costs. The CG gate introduces a unique feature for converter slide gates:The bottom plate can be exchanged while the gate remains mounted on the converter.This new feature allows for an increased utilisation of the refractory parts and a significant reduction of the downtime of the converter.This 'designed efficiency' is achieved with a refractory set consisting of three identical plates-two bottom plates and one slider plate-and a nozzle.A number of other improvements such as automatic cylinder coupling using the Interstop SNAP technology and a two step tensioning system have also been implemented. The new system is designed to meet minimal space requirements and therefore will adapt to most BOF shops.To perform preparation,service and maintenance work the modular CG gate can be dismounted from the converter and simultaneously replaced by a ready-to-use unit.The degree of automation for dismounting and mounting as well as for off-line preparation has been enhanced and reduces manual efforts. This paper provides a solution to the obvious trend towards efficient and controlled production of clean steel,in general,and especially at BOF shops.Moreover,it specifically describes the operational results of this innovative BOF tapping equipment at Salzgitter Flachstahl GmbH,Germany.

Slide Gate Bricks

1 Scope This standard specifies the classification, shape, dimension, technical requirements, test methods, quality appraisal procedures, packing, marking, transportation, storage, and quality certificate of slide gate bricks.

Effects of Four Kinds of Alumina Micropowder on Properties of Al_(2)O_(3)-C Refractories

In order to further improve the strength and the thermal shock resistance of Al_(2)O_(3)-C materials for steel ladle slide gates,the effects of four kinds of alumina micropowders(unimodal activated alumina micropowder 07RAL,unimodal activated alumina micropowder 15RA,bimodal activated alumina micropowder 22RABL,and calcined alumina micropowder 40CA)on the density,the strength and the thermal shock resistance of Al_(2)O_(3)-C materials were studied.The results show that the density,the strength and the thermal shock resistance of Al_(2)O_(3)-C materials can be improved with the introduction of activated alumina micropowders.Among them,the specimen with bimodal activated alumina micropowder shows the best comprehensive performance,especially the hot modulus of rupture.Its actual application results in steel mills show that the average service life of the Al_(2)O_(3)-C slide plates prolongs,and the problems of cast hole reaming,plate oxidation,roughening and cracking during the use of slide plates are obviously improved.

Suppression of Effect of Uneven Velocity in Submerged Entry Nozzle in Round Billet Continuous Casting Process Using Electromagnetic Swirling Flow

Sliding gate control system is widely employed in continuous casting process of steel to control flow rate of molten steel.As molten steel passes through a sliding gate,uneven flow develops.This will cause asymmetrical distribution of flow and temperature field in mold consequently,formation of vortex near the nozzle and entrapment of CC powder into the molten steel.etc,which have negative effect on process productivity and product quality.To suppress the uneven flow,electromagnetic swirling flow has been proposed to impose on the flow in submerged entry nozzle below the sliding gate.In this study the uneven flow developed by incompletely open sliding gate and the suppression of this uneven flow using electromagnetic swirling flow are numerically studied in round billet continuous casting of steel process.The improvement of the flow and temperature filed in the submerged entry nozzle and mold are investigated.It is found that:The uneven velocity in nozzle can be suppressed by electromagnetic swirling flow,and the flow and temperature field in mold be improved obviously;With the increase of electromagnetic swirling intensity,the effect of uneven flow can be almost completely suppressed.