JPS6157994B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In general, the present invention provides a method for producing carefully controlled compositions that are combusted and injected into the furnace through the apertures of a plurality of burners in the walls of a metal flake and refractory brick furnace. vertical shaft furnace (vertical blast furnace) by contacting the heat produced by the combustion of a fuel mixture with
The present invention relates to a method and apparatus for continuously and semi-continuously melting and refining metals in metals. The molten metal flows out to the bottom of the furnace and is sent for further processing.
It exits the furnace through the tap outlet in a substantially continuous stream.

Conventional vertical shaft furnaces for melting and refining metals such as copper are known, and numerous hearth configurations are used therefor for various reasons. Such vertical furnace and hearth structures are described in U.S. Pat.
No. 3,788,623 and some of the prior art cited therein. Generally, these furnaces are substantially cylindrical in shape and vertically elongated. The metal to be melted, such as the copper cathode pieces, is loaded into the furnace from an elevated position.
These charges fall towards the bottom of the furnace,
Here, a plurality of burners arranged on the walls of the furnace eject heat into the furnace to melt the metal.
Molten metal is continuously discharged from the furnace through a suitable tap outlet at the bottom of the furnace and then typically passed through a melting furnace or other process such as a continuous casting operation.

The refractory walls of conventional vertical axis furnaces generally increase in thickness from the upper portion of the furnace to the lower portion of the furnace. This often forms a funnel-shaped inner melting chamber that extends from the charge inlet to an area adjacent to the top of the hearth. The funnel-shaped refractory provides constant support as the charge melts, contracts, and travels down the axis of the furnace. This support usually works very well for large charges such as copper cathodes. However, when the charge body is first smaller than the smallest part of the funnel, e.g. copper pieces, foamed solids, consumable anodes, etc., or when the charge piece is repeatedly started and paused during continuous melting, When contracting to a smaller size during such problematic periods, the funnel support method is not effective. This results in non-molten metal being placed directly on the hearth, which can easily cause some problems in the melting and refining process.

One problem that arises with prior art vertical axis furnaces and their construction is that metal chips that reach the hearth before the burner apertures through which heat enters the furnace are completely melted can cause substantial damage to the furnace. It is possible for the system to become blocked. A blocked burner can misdirect heat generated by inefficient melting, leading to further blockage. A blocked burner burns black, which often results in malfunction and damage to the burner and its adjacent components. If a piece of metal
Mechanically blocking the burner can result in incomplete combustion. This seems particularly undesirable. This is because, especially in molten copper, the oxygen content is important. The burner ignites a mixture of fuel and oxygen-containing gas, so
Due to incomplete combustion, excessive oxygen is jetted into the furnace, thus raising the oxygen content within the molten metal above the desired or acceptable limits. Additionally, stagnant pools of molten metal can build up such that slag can form or condense, thereby creating a degraded product even if quickly remediated. This is because the slag particles cannot be uniformly dispersed again. In extreme cases,
Furnace closure, cold cleaning and double construction are required.

These problems, and the complications that arise from them, result in poor quality copper products, damaged manufacturing, and excessive expenditure of time and money to repair blocked and damaged furnaces. This results in significant economic losses.

The present invention solves these problems by providing a direct support, slightly above the hearth, for the charge pieces that reach the hearth area without melting.

A charge consisting of metal pieces, such as metal cathodes, copper pieces, foamed solids, consumable anodes, etc. or a combination of any or all of these, is continuously or semi-continuously placed in the upper part of a vertical axis furnace. can be placed in If possible, the metal should be charged irregularly, mismatched and mixed, in compact packages with spaces between the metal pieces to give an even distribution of heat and increase the rate of melting. admission must be provided. As the metal melts, it often breaks off solid pieces and flows down past the funnel-shaped internal refractory wall to the hearth, out the tap outlet, and continuously or semi-continuously into another It flows into the processing stage. At the same time, the metal pieces in the support funnel become smaller and gradually run down the funnel until they are completely melted or small enough to fall through the smallest part of the funnel. Metal pieces that have reached this size without completely melting then fall onto the novel multi-level hearth of the present invention.

Multi-level hearths are designed to separate molten solid metal. The molten metal flows to a lower level of the hearth leading to a tap outlet adjacent the lowest level of the hearth. The upper level of the hearth provides support for solid and semi-solid metal pieces.
The heat is thus evenly and reliably distributed around the supported pieces and quickly reduces them to a molten state. Thus, the present invention allows molten metal to flow down and out of the furnace substantially unrestricted by solid metal pieces. The tap outlet of the furnace is not blocked by solid metal pieces and the possibility of the burner being blocked by metal in the lower wall of the furnace is greatly reduced.

It is thus an object of the present invention to provide a method and apparatus for supporting metal pieces that reach the hearth area of a conventional vertical axis copper melting and smelting furnace without being completely melted.

Another object of the present invention is to melt irregular metal pieces such as copper pieces, foamed solids, consumable anodes, etc. without increasing the blockage problems normally associated with melting and refining small piece charges. The aim is to extend the utility of traditional vertical axis furnaces to include processing.

Another object of the invention is to distribute and distribute the heat evenly and completely over the entire circumference of the piece of metal reaching the hearth area without being melted, so as to achieve rapid melting. .

Yet another object of the invention is to ensure that metal residue can flow freely across the hearth and that the tap outlet does not become blocked by unmelted metal pieces. In particular, it is to avoid undue restriction of the gravity flow of molten metal from the vertical axis furnace to the next processing area.

Yet another object of the present invention is to prevent blockage of the lower burner of a vertical axis furnace, thus avoiding incomplete combustion of the fuel and oxygen-containing gas, and the resulting poor quality final product and misdirection. This is to avoid damage to the furnace due to heat generated by the burner or black smoke from the burner.

Another object of the invention is to provide a continuous and regular flow of molten metal which is essential in a continuous process where the metal is used for subsequent continuous operations such as continuous rod casting and rolling. To provide a more precise means of control over the amount of metal melted in a vertical axis furnace.

Yet another object of the present invention is to improve the chemical composition of the final product to provide more precise control by increasing the uniformity and predictability of the melting and refining process.

While the specification concludes with the claims particularly pointing out and distinctly claiming the subject matter regarded as the invention, it will be understood that the invention and its objects, features and advantages may be further understood from the accompanying drawings. associated with. It will become clearer from the description below. Like parts in the drawings are provided with like reference numerals.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described with reference to a preferred embodiment of the invention illustrated in the drawings. FIG. 1 shows a hearth 10 of a conventional vertical shaft furnace. The hearth 10 is usually sloped towards the tap outlet 11 and has a flat or slightly convex surface.
This hearth 10 provides support for any unmelted charge pieces that reach this area.
Has insufficient surface level variation. Some type of support is required to prevent undue restriction of the flow of molten copper and blockage of tap outlet 11.

As the following drawings show, there are several possible implementations of the invention. Combinations of basic design elements: domes, plates, smooth surfaces, and protrusions are used to construct various embodiments. In all variants, the top or upper level of the hearth is for the support of the charge, while the bottom or lower level is for the discharge of the molten metal.

FIG. 2 is a preferred embodiment of the invention adapted to a sloped hearth similar to that illustrated in FIG. This includes a multi-dome 20 and a dish element 21
These are formed by many level hearths. The unmolten metal piece is supported above the pan element 21 by the dome element 20. As the charge pieces melt due to the heat injected by the plurality of burners disposed in the refractory wall 24 of the vertical axis furnace, the molten metal flows around the dome 20; and through the recess 21 of the plate, the tap outlet 1
Flows to 1. Since the multi-level hearth is arranged horizontally on an uneven surface, the point 22 adjacent to the tap outlet 11 is at the lowest level of the multi-level hearth, so that molten metal does not accumulate in the furnace. make sure that.

FIG. 3 is another preferred embodiment of the invention. This is essentially a dish 30 shape with a variety of protruding charge supporting refractory elements 31.
When the solid pieces of the charge reach this multi-level hearth 32, the protruding charge support refractory elements 31
Their support above the dished surface 30 of the hearth 32 separates them from the molten metal. The protruding elements 31 obstruct the passage of these solid metal pieces down the slope of said pan 30, through the channel 33 and down to the tap outlet 11, so that large unmelted pieces reach the outlet and Avoid closing exits.

Naturally, these embodiments are merely illustrative of possible variations or variations. For a large number of modifications and different embodiments can be made within the scope of the inventive concept disclosed herein, and a large number of variations are hereby subject to the stated conditions of the Regulations. It will be appreciated that the details herein are to be regarded as illustrative and not in a limiting sense, as may be done in the embodiments described in detail.

[Brief explanation of the drawing]

1 is a cross-sectional view of the lower portion of a conventional vertical shaft furnace; FIG. 2 is a cross-sectional view of a first preferred embodiment of the present invention; and FIG. FIG. 3 is a cross-sectional view of a second preferred embodiment of the invention. (Explanation of symbols representing main parts of drawings), 1
0, 32: hearth, 11: tap outlet, 20: dome, 21, 30: dish, 24: refractory wall, 31: charge support refractory element, 33: channel.

Claims (1)

[Claims] 1. In a vertical blast furnace for melting and refining metal, an outer furnace wall surrounds an upright melting chamber, a charge body inlet opens at the top of the furnace, and heat is injected into the upright melting chamber to melt metal pieces. a plurality of burner openings in the inner surface of the wall for discharging the molten metal from the furnace; and a tap outlet at the bottom of the melting chamber for discharging the molten metal from the furnace; a multi-level hearth supporting a charge, the multi-level hearth having a plurality of dome-shaped protrusions offset from the center of the bottom of the vertical blast furnace; Recesses are formed between the plurality of projections, and these dome-shaped projections and recesses have relatively smooth surfaces. The closest part is the lowest level of the multi-level hearth, and the dome-shaped convex part and the furnace wall cooperate to support the unmolten metal that has reached the hearth, and the curved surface of the dome-shaped convex part supports the unmolten metal that has reached the hearth. The molten metal flows by gravity to the outer end of the dome-shaped protrusion, and the inclined intersection of the dome-shaped protrusion and the furnace wall causes the molten metal to flow under gravity around the dome-shaped protrusion. A vertical blast furnace with flow to the lowest level near the tap outlet.