Patent EA-000774-B1 (EA)
Title: Plant for transferring liquid metal and method of operation
Inventor: RICHARD FRANCOIS-NOEL
IPC: B22D41/36
Filed: 1997-10-15
Abstract: 1. Plant for transferring liquid metal from an upstream container (2) via a tapping spout (28) formed by a set of refractory assemblies, wherein each refractory assembly has at least one mating surface (22) forming a joint with a corresponding surface of an adjacent refractory assembly to a downstream container (10) comprising: a shroud channel (18; 40) placed around the tapping spout (28) and arranged at least partially at a level of the mating surface (22) and means (24) for introducing a sealing agent into the shroud channel (40; 18). 2. Plant according to claim 1, characterized in that a liquid carrier is used for transferring the sealing agent into the shroud channel (40; 18). 3. Plant for transferring liquid metal from an upstream container (2) via a tapping spout (28) formed by a set of refractory assemblies, wherein each refractory assembly has at least one mating surface (22) forming a joint with a corresponding surface of an adjacent refractory assembly to a downstream container (10) comprising: a shroud channel (18; 40) placed around the tapping spout (28) and arranged at least partially at a level of the mating surface (22) having an inlet (44) and the liquid carrier provides the delivery of the sealing agent into the shroud channel (40; 18) via the inlet. 4. Plant according to claim 2 or 3, characterized in that the liquid carrier comprises inert gas. 5. Plant according to any one of the preceding claims, characterized in that means (33, 34; 36) for introducing a sealing agent comprise a cartridge 33) mounted on a pipe (24) connected to the inlet (44) of the shroud channel (40; 18). 6. Plant for transferring liquid metal according to any one of the preceding claims, characterized in that means (33, 34; 36) for introducing a sealing agent comprises a cartridge 33 comprise means (34) enabling predetermined doses of sealing agent to be introduced into the shroud channel. 7. Plant according to any one of the preceding claims, characterized in that the shroud channel. (40) comprises an outlet (46) capable of allowing materials to escape. 8. Plant claim 7, characterized in that the inlet (44) of the shroud channel (40) is at one end of this channel and the outlet (46) is at the other end. 9. Plant according to either of claims 7 and 8, characterized in that the shroud channel (40) is continuous. 10. Plant according to any one of claims 7 to 9, characterized in that means capable of maintaining a pressure at the outlet (46) of the shroud channel (40) are connected to the outlet (46) of the shroud channel (40), while still allowing an excess of sealing agent to escape. 11. Plant according to claim 10, characterized in that the means capable of maintaining a pressure at the outlet (46) of the shroud channel (40), while still allowing an excess of sealing agent to escape are a calibrated head loss (51) terminated by a venting outlet (62). 12. Plant according to any one of the preceding claims, characterized in that the sealing agent is a pulverized product. 13. Plant according to any one of the preceding claims, characterized in that the pulverized product is a powder.  14. Plant according to any claim 1-3, 12, 13, characterized in that the power includes particles of various sizes. 15. Plant according to any one of the preceding claims, characterized in that the powder is a fusible product, enable to melt for sealing of leaks in the shroud channel (40; 16). 16. Plant according to any one of the preceding claims, characterized in that the sealing agent is a non-volatile product, chosen from salts and metals, which is liquid at the temperature of the shroud channel (18; 40). 17. Plant according to any one of the preceding claims, characterized in that the sealing agent comprises an inflammable material. 18. Plant claim 7, characterized in that the inflammable material comprises graphite. 19. Plant according to any one of the preceding claims, characterized in that the inner walls of the shroud channel (18; 40) are coated with an impermeable layer of the sealing agent. 20. Method for protection of the liquid metal flow in the tapping spout (28) formed by a set of refractory assemblies and in the shroud channel (18; 40) placed around the tapping spout (28), characterized in that the sealing agent is introduced into the tapping spout. 21. Method according to claim 20, characterized in that the sealing agent is introduced in the form of a wire which melts when it enters the shroud channel (40; 18). 22. Method according to any one of claims 10 to 18, characterized in that the sealing agent is produced by the reaction of at least two substances which are inactive at ambient temperature but which react together at the temperature of the shroud channel (18; 40). 23. Method according to any one of claims 20 to 22, characterized in that the sealing agent is introduced continuously. 24. Method according to any one of claims 20 to 22, characterized in that the sealing agent is introduced intermittently. 25. Method according to any one of claims 20 to 24, characterized in that the liquid carrier is used for transferring the sealing agent into the shroud channel (40; 18). 26. Method according to claim 25, characterized in that  the liquid carrier is introduced at a predetermined pressure; the flow rate of the liquid carrier flow is measured; the sealing agent is introduced when the value of the said flow rate exceeds a predetermined value. 27. Method according to claim 25, characterized in that the liquid carrier is introduced into the shroud channel (40; 18) at a predetermined flow rate; the pressure of the liquid carrier in the shroud channel (40; 18) is measured; the sealing agent is introduced when the value of the said flow rate falls below a predetermined value. 28. Method according to claim 25, characterized in that the liquid carrier is introduced into the shroud channel (40; 18) at a predetermined flow rate; the flow rate at the venting outlet (62) is determined; the set value is adjusted in such a way that the flow rate is always positive; the flow rate is determined by the difference between the flow rate at the inlet into the shroud channel (40) and the flow rate at the venting outlet (62); a sealing agent is introduced into the shroud channel (40) when the said flow rate exceeds a permitted limit.