Spray Cooled Funnel Mold

Abstract

A funnel shaped mold for casting slabs of steel which is configured to be cooled by a fine spray of a cooling liquid on the outside of the mold.

Claims

1. A funnel mold system comprising: a funnel mold comprising: an upper end: a lower end; an interior comprising a funnel section proximate the upper end of the mold and a narrow face section adjacent to the funnel section and extending to the lower end of the mold: and mold walls which enclose four sides of the interior section; and a spray cooling system comprising: a plurality of liquid spray nozzles configured to spray cooling liquid on the entirety of the mold walls.

2. The funnel mold as defined in claim 1 wherein the spray nozzles are further configured to spray three to five times the volume of cooling liquid on the funnel wall than the remaining portions of the mold walls.

3. The funnel mold as defined in claim 1 wherein the liquid spray nozzles are configured to spray cooling liquid with a droplet size between 0.008 in. and 0.210 in. and a droplet density between 250 and 460 droplets per square inch.

4. The funnel mold as defined in claim 3 wherein the spray nozzles are further configured to spray three to five times the volume of cooling liquid on the funnel wall than the remaining portions of the mold walls.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In the following drawings, which form a part of the specification and which are to be construed in conjunction therewith, and in which like reference numerals have been employed throughout wherever possible to indicate like parts in the various views:

[0036] FIG. 1 is an isometric view of the design of the conventional slab mold;

[0037] FIG. 2 is a top view of the conventional slab mold;

[0038] FIG. 3 is an isometric view of the funnel mold which illustrates the funnel section and narrow face section; and

[0039] FIG. 4 is an isometric view of the funnel mold with a spray cooling system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] Referring more specifically to the drawings, typical prior art systems for casting slabs are indicated generally in FIGS. 1 and 2. Prior art molds 10 utilize exterior walls 11 of uniform thickness and an interior 12 with a uniform cross section which matches the size of the steel slab being produced. In operation, molten steel 13 is placed in the top of the mold 10 and a solid steel slab 14 is continuously withdrawn from the bottom of the mold.

[0041] Referring to the drawings FIG. 3 shows the configuration of the funnel mold 20. The funnel mold comprises an interior section 21 and mold walls 22. The funnel mold has an upper end 23 and a lower end 24. The interior section 21 is open and goes through the entirety of the mold 20 such that it is open continuously from end to end. At the upper end 23 of the mold, the interior section 21 has a funnel section 25 configured such that molten steel may be poured into it. The funnel section 25 is shaped generally as an elongated bowl and tapers inward as depicted in FIG. 3. The interior section 21 also features a narrow face section 26 which is dimensioned the same as the desired slab width and thickness and is generally less thick than the funnel section. The narrow face section 26 is located in the interior section 21 in all areas where the funnel section 25 is not. Preferably, the narrow face section is located below the funnel section and extends to the lower end 24 of the funnel mold as well as laterally to the sides of the funnel section 25 proximate the upper end 23. The funnel mold is preferably made of copper.

[0042] The walls 22 of the funnel mold 20 are preferably made of copper and form a complete enclosure around four sides of the interior section 21 of the mold. The walls are generally a uniform thickness, but may be thinner adjacent to the funnel section 25 of the interior as depicted in FIG. 3. This section adjacent to the funnel section is referred to as the funnel wall 27. The walls may also be configured such that the walls are of complete uniform thickness and follow the contour of the funnel section 25 to produce walls with an irregular exterior shape and uniform thickness.

[0043] To help reduce the sliding frictional forces encountered when casting steel slabs, high temperature melting point casting powders may be employed to form a lubricating barrier between the solidifying steel and the copper mold wall. Due to the differential ferrostatic pressures encountered within the funnel design, significant differential sliding frictional forces within the slab mold may be encountered. The result of these frictional forces also affects the metallurgical properties of the solidifying steel slab.

[0044] To overcome the detrimental effects of the frictional forces a spray cooling system 30 is utilized. The cooling system comprises a plurality of high pressure, high flow rate nozzles allocated at strategic locations conforming to the irregular shape of the funnel section of the slab mold indicated in FIG. 4. The nozzles 31 are configured such that the entire surface of the mold walls 22 are reached by the spray for cooling. The nozzles 31 are further configures such that the funnel wall 27 receives a spray with a flow of three to five times the volume of water sprayed on the rest of the walls 22. Although the spray nozzles are depicted in a vertical position in FIG. 4, it is understood that they may also be configured in a horizontal array.

[0045] The invention results in superior quality of the cast steel slab, increased productivity, and reduction, or, for some grades of steel cast, elimination of, the requirement for the application of high temperature casting powders to reduce the sliding frictional forces encountered.