FEEDING/DISTRIBUTION DEVICE OF A CONTINUOUS CASTING MACHINE

Abstract

 A feeding/distribution device of a continuous casting machine, including an upper shell joined to a lower shell so as to form a chamber which has an inlet and an outlet; the device is installed at casting rolls of the machine in order to feed liquid aluminum or zinc to the casting rolls; the device is characterized in that it is made of composite materials based on carbon, graphite, calcium silicate.

Description

[0001] The present invention relates to a feeding/distribution device of a continuous casting machine.

[0002] More particularly, the present invention relates to a feeding/distribution device, known as tip, installed in a continuous casting machine, known as caster, for the production of aluminum or zinc strips.

[0003] The tip is designed to feed the aluminum or zinc in liquid form to the casting rolls and is installed between the rolls on the inlet of the molten metal.

[0004] US2017106435A1 discloses a caster tip for a twin roll continuous strip caster for non-ferrous metals. The caster tip includes a caster tip body made primarily of a ceramic material, and an electric resistance heater thermally connected to the caster tip body for pre-heating the caster tip body to a predetermined temperature.

[0005] GB2524962 discloses a feed tip made from N17, a calcium silicate refractory material which is commonly used in TRC feed tips, in order to be non-conductive and non-magnetic so as to be transparent to the magnetic fields generated by the electromagnetic edge dam.

[0006] US2014367065 discloses a thin roll strip caster having delivery nozzles made of a refractory material such as zirconia graphite, alumina graphite.

[0007] US2013/089457 discloses a composite material suitable for use in a continuous casting nozzle and formed by a body and a filler. The body is formed by compression-molding silicon carbide fibers or carbon fibers into a compact and baking the compact. The form of carbon fibers may be staple fibers or filament fibers. The porous body may be a porous carbon substrate having an average pore size of about 5 µm, a C/C composite or a porous body composed of alumina or alumina fibers.

[0008] GB1287510 discloses a flat injection nozzle made of a highly refractory material such as graphite and having lateral cheeks also made of graphite or like highly refractory material.

[0009] US5259439 discloses a delivery nozzle formed as an elongate body made of a refractory material such as alumina graphite.

[0010] EP1867412 discloses a nozzle having a pouring port side main body formed of aluminum sintering compact and a pouring basin side main body formed of graphite. On the inner surface of the main body a coating layer is provided at a portion except the vicinity of a pouring port. The coating layer is made by preparing a boron nitride spray in which boron nitride powder is mixed in solvent (ethanol), and a graphite spray in which graphite powder is mixed in solvent (ethanol), by repeating ten times an operation of laminating the powders on the inner surface of the main body, except the vicinity of pouring port where masking is applied, using alternately the both sprays, and thereafter sintering the laminated powders at 300°C temperature. Alternatively, the pouring port side main body is formed of boron nitride sintering compact, and the pouring basin side main body is formed of graphite. On the inner surface of this main body a coating layer is provided partially on the inner surface of the pouring port side main body.

[0011] US4619309 discloses that nozzles for metal feeding have been developed wherein the parts of the nozzle which come into contact with the liquid metal are made of a refractory material made up of a mixture of 30% diatomaceous earth (almost pure silica in the form of microscopic cells), 30% asbestos fibers, 20% sodium silicate (dry weight) and 20% lime (to form calcium silicate).

[0012] Currently, in its normal use, the tip, made of ceramic fiber, has an average lifespan of approximately ten days of continuous casting of aluminum and approximately fifteen days for zinc.

[0013] The replacement of the tip obviously entails stopping the continuous casting apparatus in order to remove the depleted tip and install a new one.

[0014] The tip is constituted by two shells, an upper one and a lower one, and baffles, also made of ceramic material, are located inside it and have the purpose of conveying the flow of liquid metal.

[0015] The width and length (depth) of the tip are sized in relation to the width of the strip to be produced and to the diameter of the roll installed on the caster.

[0016] During continuous casting, the wear of the tip, which is made of ceramic fiber, generates a continuous degradation of the quality of the produced strip.

[0017] The causes of this deterioration are due to thermal stress, chemical aggression, and mechanical abrasion, for example due to an incorrect placement of the setback.

[0018] In addition to the loss of production time, the replacement of the tip also entails inconveniences for its maintenance (removal and assembly) and for its disposal.

[0019] The tip is in fact made of material that is considered carcinogenic.

[0020] Traditional ceramic tips have long been considered materials that are carcinogenic by inhalation, rated R49 according to the R-Phrase system, currently replaced by H-Phrases.

[0021] Therefore, at the end of the life of the ceramic tip it is necessary to provide for the special disposal of the tip, adding to the management costs for the company.

[0022] The aim of the present invention is to provide a feeding/distribution device of a continuous casting machine that overcomes the drawbacks of the cited prior art.

[0023] Within the scope of this aim, an object of the invention is to provide a feeding/distribution device of a continuous casting machine that ensures a substantially longer operating life with respect to the tips of the prior art.

[0024] A further object of the invention is to provide a feeding/distribution device of a continuous casting machine that allows to obtain a product with superior technical characteristics with respect to tips of the traditional type.

[0025] A further important object of the invention is to provide a feeding/distribution device of a continuous casting machine that eliminates the carcinogenic risk.

[0026] Another object of the present invention is to provide a device which, by virtue of its particular constructive characteristics, is capable of giving the greatest assurances of reliability and safety in use.

[0027] This aim and these and other objects which will become better apparent hereinafter are achieved by a feeding/distribution device of a continuous casting machine, comprising an upper shell joined to a lower shell so as to form a chamber which has an inlet and an outlet; said device being installed at casting rolls of a continuous casting machine in order to feed liquid aluminum or zinc to said casting rolls; said device being characterized in that it is made of composite materials based on carbon, graphite, calcium silicate.

[0028] Further characteristics and advantages will become better apparent from the description of preferred but not exclusive embodiments of the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a partially sectional schematic side view of the feeding/distribution device according to the present invention, installed at the casting rolls;

Figure 2 is a sectional side view of the feeding/distribution device according to the present invention;

Figure 3 is a transverse sectional view of the device of the preceding figure and in which the baffles inside of the device are visible;

Figure 4 is another transverse sectional view of the device of Figure 2;

Figure 5 is a perspective view of the device;

Figure 6 is a plan view of the upper shell of the device;

Figure 7 is a longitudinal sectional view of the upper shell of the device.

[0029] With reference to the cited figures, the feeding/distribution device of a continuous casting machine, according to the invention, globally designated by the reference numeral 1, includes an upper shell 2, which is joined to a lower shell 3 so as to form a chamber 4 which has an inlet 5 and an outlet 6.

[0030] The feeding/distribution device 1, commonly known as tip, is installed in a continuous casting machine, known as caster, for the production of aluminum or zinc strips.

[0031] The feeding/distribution device 1 feeds the liquid aluminum or zinc to the casting rolls 20 of the machine and is installed between the rolls 20, on the inlet of the molten metal, as shown schematically in Figure 1.

[0032] The width and length (depth) of the feeding/distribution device 1 are sized in relation to the width of the strip to be produced and to the diameter of the rolls 20.

[0033] Inside the feeding/distribution device 1 there are baffles 7 which have the task of conveying the flow of the liquid metal.

[0034] According to the present invention, the feeding/distribution device is made of composite materials based on carbon, graphite, calcium silicate.

[0035] The provision of the feeding/distribution device 1 with a new refractory material, without using ceramic materials, allows to obtain various and considerable advantages.

[0036] First of all, the feeding/distribution device according to the present invention eliminates the R49 carcinogenic inhalation danger.

[0037] A further advantage is constituted by the fact of using an environmentally friendly material, which is not classified as dangerous, with consequent elimination of the problem of the disposal of the material.

[0038] The feeding/distribution device according to the present invention ensures, by means of the innovative refractory composite material, an operating life that is extended substantially, up to approximately 300%, with respect to traditional ceramic materials.

[0039] The feeding/distribution device according to the present invention has resistance to wear and to high temperatures.

[0040] A further advantage is constituted by the fact that defects caused by thermal and chemical fatigue phenomena are eliminated.

[0041] A further important advantage of the feeding/distribution device according to the present invention is constituted by the reduction of the stops of the caster, with consequent productivity increase.

[0042] The increase in productivity is associated with a significant increase in the quality of the final product.

[0043] A further advantage, from the point of view of costs, is provided by the possibility to reuse the internal members, i.e., the baffles of the tip, for multiple casting campaigns.

[0044] In practice it has been found that the invention achieves the intended aim and objects, providing a feeding/distribution device, particularly studied for continuous casting machines for the production of strips of aluminum or zinc, that allows to improve the quality of the product and most of all eliminates the risks due to the use of ceramic materials according to the background art.

Claims

1. A feeding/distribution device of a continuous casting machine, comprising an upper shell joined to a lower shell so as to form a chamber which has an inlet and an outlet; said device being installed at casting rolls of a continuous casting machine in order to feed liquid aluminum or zinc to said casting rolls; said device being characterized in that it is made of composite materials based on carbon, graphite, calcium silicate.

2. The device according to claim 1, characterized in that the width and length or depth of said device are sized in relation to the width of the strip to be produced and to the diameter of said rolls.

3. The device according to claim 1, characterized in that it comprises baffles arranged in said chamber in order to convey the flow of the liquid metal.

Drawing