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EP-4598699-B1 - COOLING UNIT FOR A METALLURGICAL FURNACE

EP4598699B1EP 4598699 B1EP4598699 B1EP 4598699B1EP-4598699-B1

Inventors

  • ZIVANOVIC, BOJAN

Dates

Publication Date
20260513
Application Date
20231004

Claims (15)

  1. Cooling unit (1) for a metallurgical furnace, the cooling unit (1) comprising a cooling body (2) and at least one cooling conduit (3) leading through the cooling body (2), wherein a cooling liquid can be conducted via the at least one cooling conduit (3), characterized in that the cooling body (2) comprises a casing (20) and a core material (21), said casing (20) having an inner space (I) filled with said core material (21), said core material (21) at least partially embedding the at least one cooling conduit (3), wherein the material of the casing (20) has a melting point of at least 100°C higher, preferably of at least 200°C higher, than the core material (21).
  2. Cooling unit (1) according to claim 1, characterized in that the casing (20) comprises cast steel and/or cast iron and/or cast copper.
  3. Cooling unit (1) according to any one of claims 1 or 2, characterized in that the casing (20) comprises steel plates, preferably welded steel plates.
  4. Cooling unit (1) according to any one of claims 1 to 3, characterized in that the core material (21) has a boiling point above 900°C, preferably above 1650°C.
  5. Cooling unit (1) according to claim 4, characterized in that the core material (21) has a melting point from 200°C to 900°C.
  6. Cooling unit (1) according to any one of claims 1 to 5, characterized in that the core material (21) comprises one or more of the following materials: zinc, tin, aluminum.
  7. Cooling unit (1) according to any one of claims 1 to 6, characterized in that at least part of an outer surface (31) of the number of cooling conduits (3) is uncovered by the core material (21).
  8. Cooling unit (1) according to any one of claims 1 to 7, characterized in that the number of cooling conduits (3) are mainly covered by the core material (21).
  9. Cooling unit (1) according to any one of claims 1 to 8, characterized in that side walls (S) of the casing (20) comprise a number of apertures (A), wherein the core material (21) fills the inner space (I) up to an edge of said number of apertures (A) closest to a bottom (B) of the casing (20).
  10. Cooling unit (1) according to any one of claims 1 to 9, characterized in that side walls (S) of the casing (20) comprise mounting means (M) for mounting the cooling unit (1) at a furnace roof and/or a furnace wall.
  11. Cooling unit (1) according to any one of claims 1 to 10, characterized in that a bottom (B) of the casing (20) comprises a number of attaching means (5), preferably for connection to a refractory brick.
  12. Metallurgical furnace comprising a heat source, a furnace bottom, a furnace wall, a furnace roof and a cooling unit (1) according to one of claims 1 to 11 mounted on the furnace roof or the furnace wall.
  13. Method for manufacturing a cooling unit (1) for a metallurgical furnace, characterized in that a casing (20) comprising a bottom (B) and an inner space (I) is provided, wherein cooling conduits (3) are provided within the inner space (I), that liquid core material is cast into the inner space (I) to at least partly embed the cooling conduits (3), the material of the casing (20) having a melting point of at least 100°C higher, preferably of at least 200°C higher, than the core material (21), and that the liquid core material is cooled down to solidify representing the core material (21).
  14. Method according to claim 13, characterized in that a casing (20) having an upper opening (O) is provided, and that the liquid core material is cast into the inner space (I) through the upper opening (O).
  15. Method according to any one of claims 13 or 14, characterized in that the provided casing (20) comprises side walls (S) with a number of apertures (A), that the casing (20) is immersed into a bath of liquid bulk core material, and that the casing (20) is removed from the bath of liquid bulk core material, such that excess liquid bulk core material flows out of the inner space (I) through the apertures (A) and the remaining liquid bulk core material represents the liquid core material.

Description

The current disclosure relates to a cooling unit for a metallurgical furnace, the cooling unit comprising a cooling body and at least one cooling conduit leading through the cooling body, wherein a cooling liquid can be conducted via the at least one cooling conduit. Furthermore, the current disclosure relates to a metallurgical furnace comprising a heat source, a furnace wall, a furnace roof and a cooling unit and a method for manufacturing a cooling unit for a metallurgical furnace. Due to high operating temperatures and harsh chemical and mechanical conditions metallurgical furnaces are, in general, lined with refractory materials. In addition, furnace zones which experience particularly high refractory wear due to very high temperatures or chemical or mechanical stress, can be supplied with cooling units as described e.g. in DE 10 2015 001 190 A1. This can help to reduce said high refractory wear in those zones and thus helps to increase the total lifetime of the refractory lining and reduce furnace downtimes. A cooling unit comprises a cooling body for conducting heat away from the furnace and cooling lines. Cooling liquid flows through the cooling lines to dissipate the heat from the cooling body. Inexpensive cooling bodies can be made of welded steel, which leads to low material costs but considerable welding costs. If the cooling body comprises welded cooling body parts, cooling lines can be formed between said welded cooling body parts. So, the cooling lines are defined by said welded cooling body parts and cooling liquid flows directly within the cooling body without additional cooling conduits. However, the corresponding welding seams are potential weak spots, carrying the risk for cooling liquid leakage. Also, those cooling lines usually have a polygonal, e.g., rectangular, cross section which, compared to a circular cross section, has several potential disadvantages, such as pressure loss and inhomogeneous flow speed, flow turbulences and/or flow interruption of the cooling liquid. Also, often linear flow of the cooling liquid is not possible due to geometric limits of welded cooling lines. To prevent this, cooling lines in the form of cooling conduits can be provided, wherein copper cooling bodies can be cast around the (steel) cooling conduits. Cooling units comprising cast copper cooling bodies and cooling conduits within said cooling bodies are waterproof and have no limitations regarding the inside and outside design. Copper has a relatively high thermal conductivity compared to steel but is much more expensive. Also, cooling conduits can be drilled into solid copper cooling bodies, which still leads to high material costs. To drill cooling conduits into the copper cooling bodies drill holes in the surface of said copper cooling bodies are produced and have to be sealed by screws or by welding - which again are potential weak spots and might lead to cooling liquid leakage. Alternatively, cast steel or (grey) cast iron cooling bodies can be used instead but are difficult to manufacture due to the high melting point of steel or iron, which requires high energy effort and the use of refractory molds that can withstand those high temperatures. As the cooling conduits are usually also made of steel, cast steel or cast iron cannot easily be cast around said steel cooling conduits as said cooling conduits might melt without any additional refractory surface coating. It is therefore an object of the invention to provide a cooling unit which is inexpensive and waterproof. This object has been achieved by the cooling body comprising a casing and a core material, said casing having an inner space filled with said core material, said core material at least partially embedding the at least one cooling conduit, wherein the material of the casing has a melting point of at least 100°C higher, preferably of at least 200°C higher, than the core material. The cooling unit according to this disclosure in comparison to welded cooling lines prevents cooling liquid leakage as a number of cooling conduits is used, whose outside surface is at least partially embedded into the core material. The cooling unit according to this disclosure can be used with various furnaces, e.g., copper flash smelting furnaces, copper flash converting furnaces, FeTi Electric furnaces, Ilmenite DC furnaces, FeCr DC furnaces, TKSE DRI Smelter etc. A metallurgical furnace might comprise a heat source, a furnace bottom, a furnace wall and a furnace roof and a cooling unit according to this disclosure. The cooling unit as disclosed herein can be mounted on the furnace roof or the furnace wall. Heat generated by the heat source is conducted through the casing to the core material and further through the cooling conduits to the cooling liquid and is further dissipated by the cooling liquid flowing through the cooling conduits. All temperatures (e.g., melting points, boiling points etc.) in this disclosure are referred to as being under stand