CERAMIC FILTERS AND FILTER SYSTEMS FOR CONTINUOUS METAL MELT FILTRATION

Abstract

With respect to ceramic filters and filter systems for continuous metal melt filtration, to be able to counter high throughputs of steel melt and also the limitations of filter capacities during continuous casting, an alternative technological approach involves the use of novel, replaceable, and/or rotatable filter bodies at positions in the distributor channel. In some cases, the replaceable and/or rotatable filter bodies may be inserted into the distributor channel for 10 seconds to 30 minutes before being replaced. The filter bodies may be configured as an open-celled foam ceramic or a honeycomb body or a spaghetti filter and serve as a filter geometry of the replaceable and/or rotatable filter bodies in the distributor channel.

Claims

1. A system comprising: a distributor channel; and ceramic filters or filter systems for continuous metal melt filtration, wherein replaceable and/or rotatable filter bodies are disposed at positions in the distributor channel.

2. The system of claim 1 wherein the ceramic filters or the filter systems are configured to contribute at least one of directly to removal of inclusions by generating in-situ layers on filter surfaces of the ceramic filters or the filter systems on which the inclusions deposit and lead via sintering processes to fastening on the filter surfaces, or indirectly to removal of inclusions by shortening a path for deposition of nonmetallic inclusions into a slag of the distributor channel by a design of filter geometries in combination with rotation of the filter bodies and flow of metal melt in the distributor channel.

3. The system of claim 2 wherein the filter bodies configured as an open-celled foam ceramic or a honeycomb body or a spaghetti filter serve as the filter geometries of the replaceable and/or rotatable filter bodies in the distributor channel.

4. The system of claim 2 wherein porous, replaceable and/or rotatable vessels in which stamped fibres or fibre fabrics or spheres or splintering particles are present serve as the filter geometries of the replaceable and/or rotatable filter bodies.

5. The system of claim 1 wherein at least one filter body is used in an end face of the distributor channel and/or in a vicinity of a shadow tube in the distributor channel.

6. The system of claim 1 further comprising foam ceramics or spaghetti structures with macrochannels and a minimum diameter of 10 mm.

7. A process that employs ceramic filters or filter systems for continuous metal melt filtration, wherein replaceable and/or rotatable filter bodies are disposed at positions in a distributor channel.

8. The process of claim 7 further comprising: dipping the ceramic filters or the filter systems into the distributor channel for 10 seconds to 30 minutes; and replacing the ceramic filters or the filter systems.

9. The process of claim 7 wherein the ceramic filters or the filter systems contribute at least one of directly to removal of inclusions by generating in-situ layers on filter surfaces of the ceramic filters or the filter systems on which the inclusions deposit and lead via sintering processes to fastening on the filter surfaces, or indirectly to removal of inclusions by shortening a path for deposition of nonmetallic inclusions into a slag of the distributor channel by a design of filter geometries in combination with rotation of the filter bodies and flow of metal melt in the distributor channel.

10. The process of claim 9 wherein the filter bodies configured as an open-celled foam ceramic or a honeycomb body or a spaghetti filter serve as the filter geometries of the replaceable and/or rotatable filter bodies in the distributor channel.

11. The process of claim 9 wherein porous, replaceable and/or rotatable vessels in which stamped fibres or fibre fabrics or spheres or splintering particles are present serve as the filter geometries of the replaceable and/or rotatable filter bodies.

12. The process of claim 7 wherein at least one filter body is used in an end face of the distributor channel and/or in a vicinity of a shadow tube in the distributor channel.

13. The process of claim 7 further comprising providing foam ceramics or spaghetti structures with macrochannels and a minimum diameter of 10 mm.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0008] FIG. 1, at left, is a sectional view of an example cylindrical filter body with macrochannels and an external diameter of 200 mm, and FIG. 1, at right, is a perspective view of an example “chaotic” spaghetti filter structure, which is 80 mm in height, includes a 120 in diameter, and has a spaghetti thickness of 2.5 mm.

DETAILED DESCRIPTION

[0009] To be able to counter the high throughputs of the steel melt and also the limitations of the filter capacities during continuous casting, an alternative technological approach using novel, replaceable and/or rotatable filter bodies at positions in the distributor channel is pursued according to the present disclosure. The filter bodies can, according to the present disclosure, contribute directly to removal of inclusions (generation of in-situ layers on their filter surfaces on which the inclusions deposit and lead via sintering processes to fastening to the filter surface) and/or indirectly by the path for deposition of the nonmetallic inclusions into the slag of the distributor being shortened by the design of the filter geometry and in combination with the rotation of the filter body and the flow of the steel melt in the distributor. In addition, larger agglomerates/clusters which owing to their size (additional contribution of buoyancy) move in the direction of the slag can be generated according to the present disclosure by targeted setting of the flow.

[0010] According to the present disclosure, filter bodies in the form of an open-celled foam ceramic, a honeycomb body or a spaghetti filter serve as replaceable and/or rotatable filter geometries in the distributor or distributor channel. According to the present disclosure, porous, replaceable and/or rotatable vessels in which stamped fibres or fibre fabrics or spheres or splintering particles are present serve as filter bodies.

[0011] According to the present disclosure, the filter bodies are, depending on the metal alloy and the preceding secondary metallurgy, dipped into the distributor channel for from 10 seconds to 30 minutes and then replaced. According to the present disclosure, at least one filter body is used in the distributor channel. According to the present disclosure, filter bodies are used in the end faces of the distributor channel. According to the present disclosure, four filter bodies can be used in the vicinity of the shadow tube in the distributor channel.

[0012] According to the present disclosure, refractory oxides and/or non-oxides in combination with or without carbon serve as filter materials. According to the present disclosure, cylindrical carbon-bonded filter bodies based on foam ceramics or spaghetti structures having macrochannels having a minimum diameter of 10 mm are used. According to the present disclosure, filter bodies having a minimum diameter of 100 mm and a height of 100 mm are employed. According to the present disclosure, carbon-bonded support materials can be coated with oxides on their surface in a manner analogous to the patent document DE 10 2011 109 681 B4.