RU201236U1 - SHORT NETWORK OF ORE-THERMAL ELECTRIC ARC FURNACE FOR MELTING OF OXIDE REFRACTORY MATERIALS - Google Patents

Abstract

The utility model relates to the refractory industry, namely to the construction of a short network of an ore-thermal electric arc furnace for melting various oxide refractory materials and obtaining fused materials that are used for the production of refractory products. A short network of an ore-thermal electric arc furnace for melting oxide refractory materials contains rigid sections, both vertical and horizontal, bridges, fixed shoes spaced in height for different phases, flexible strings and contact jaws of the electrode clamping device. The flexible string from the fixed shoes to the contact cheeks of the electrode clamping device is made horizontal. Reducing the inductance of a short network is provided, which makes it possible to increase the productivity of the furnace and reduce specific energy consumption, 8 silt.

Description

The utility model relates to the refractory industry, namely to the construction of a short network of an ore-thermal electric arc furnace for melting various oxide refractory materials and obtaining fused materials that are used for the production of refractory products.

In the refractory industry, tilting ore smelting furnaces for melting low-melting alumina-containing materials have been used relatively recently. In fact, steelmaking furnaces of medium power began to be used with minor alterations of the furnace bath and lining. Thus, the switching circuit "triangle on fixed shoes" and the design of a short network of steel-making furnaces passed to tilting ore-thermal furnaces for melting oxide refractory materials without any significant changes (1, p. 88-92), (3, p. 31-34 , 77-82).

Since the short circuit of the steelmaking furnace must ensure the limitation of the short circuit current during metal melting, it has an increased inductive resistance, which, when melting oxide refractory materials, where there is no short circuit mode, leads to increased power consumption.

For the melting of refractory magnesium-containing materials on the block, an OKB-616 furnace was initially used (1, p. 150-151), (2, p. 106-107), and then a universal ore-thermal furnace OKB-955 N, (4, p. 31 -35), subsequently RK3-1.2 in which the "triangle on fixed shoes" scheme was applied and the short network is made with vertical sections and has a bus bridge (jumpers) for switching on various circuits for connecting the windings of the low side of the furnace transformer. Such a switching scheme and versatility required an increase in the length of a short network and, as a consequence, an increase in electrical losses in it.

All ore-thermal furnaces for melting oxide refractory materials use the design of electrode holders in the form of "G", along the upper part of which there are pipelines through which current is supplied to the contact cheeks of the electrode clamping device.

Several schemes are known for switching on the windings of the low side of the furnace transformer,

- triangle on fixed shoes

- triangle on movable shoes

- a triangle on the electrodes.

For furnaces of different power, different switching schemes are used, it is generally accepted that for low-power furnaces up to 2 MVA, a simpler, but with increased inductive resistance, triangle circuit on fixed shoes is used, the more powerful the furnace, the more they try to use a circuit with a lower inductive resistance, up to 5 MVA- a triangle on movable shoes, over 5 MVA circuit with a minimum inductance - a triangle on the electrodes.

In the marketplace and with the ever-increasing price of electricity, the competitiveness of our fused refractory materials is a pressing issue. Therefore, reducing energy costs is very important for the refractory industry.

Simple use of the "triangle on electrodes" switching circuit, as it is done on high-power furnaces, for ore-heating furnaces of low and medium power is complicated by the design of "L" -shaped electrode holders, therefore such a scheme was rarely used.

In all switching schemes, the sections of flexible strings and pipelines have the largest inductive resistance, each 30% of the total inductance of a short network (5, p. 143, Table 3.11), while the inductance of the jumpers is not taken into account due to the great complexity of its calculation, therefore, reducing the inductance of these sections will significantly reduce the inductance of the entire short network.

The task of the utility model is to reduce the inductance of pipeline sections of a short network for any connection scheme.

The technical result is an increase in the productivity of the melting process and a decrease in specific energy consumption per ton of obtained fused materials.

To solve the problem and achieve the technical result, according to the formula of the utility model, a short network of an ore-thermal furnace containing rigid sections, both vertical and horizontal, jumpers, fixed shoes, flexible garlands, movable shoes and pipelines to the contact cheek of the electrode clamping device, differs in that , that in order to reduce the inductive resistance of the phases, it is made with a minimum height of vertical sections and a minimum length of horizontal sections, and instead of pipelines, a flexible garland is used from fixed shoes to contact cheeks of the electrode clamping device, made horizontally with a minimum sag at one level or spaced apart in height for different phases. An even better result is obtained when using a short network, which is made without jumpers, and their function is performed by a flexible garland made horizontally with minimal sag and spaced in height for different phases.

The essence of the utility model is that in 1 case a flexible string excludes a section of pipelines, and in 2 it combines sections of jumpers with a flexible string and excludes a section of pipelines.

This design allows to reduce the inductive resistance of the entire short network by 15-30%, which increases the productivity of the furnace and reduces specific energy consumption.

The utility model is illustrated by an example of performing a short network for melting to drain, shown in figure No. 1 A and B, for melting on a block - in figure No. 2 A and B, and by an example of performing a short network for melting to drain - in figure No. 3 A and B, for melting on the block - in figure No. 4 A and B. The furnace transformer is shown conventionally in the figures.

The claimed short network contains: a vertical section of rigid tires - 1; horizontal section of rigid tires - 2; jumpers - 3; fixed shoes, at the same level or spaced apart in height for different phases - 4; flexible garland excluding pipelines - 5; flexible garland simultaneously acting as jumpers and excluding pipelines - 6; contact cheeks of the electrode clamping device - 7; electrode holders - 8.

The short network of the ore smelting furnace is arranged as follows.

If the ore-smelting furnace is intended for melting low-melting alumina-based materials by the drain method, FIG. 1 and FIG. 3, then the flexible string is attached to the fixed shoe and the contact cheeks of the electrode clamping device as horizontally as possible and has a length sufficient to provide a minimum sag for moving the electrodes up and / or down, and to tilt the furnace bath to the required angle to drain the melt into mold.

If the ore smelting furnace is intended for block smelting of particularly refractory materials based on magnesium oxide, FIG. 2 and FIG. 4, then the flexible string is attached to the stationary shoe and the contact cheeks of the electrode clamping device as horizontally as possible and has a length sufficient to provide minimal slack for moving the electrodes only up and / or down.

In both cases, flexible strings are made with insulating washers and / or plates to prevent short circuits with each other.

As practice has shown, the proposed design of a short network of ore-thermal furnaces for melting oxide refractory materials makes it possible to increase the furnace productivity, reduce specific energy consumption and solve the problem.

1. Electric industrial ovens. Ed. HELL. Svenchansky. M. "Energoizdat" 1981 p. 88-92.

2. Industrial installations of electric arc heating and their parameters. Under total. ed. L.E. Nikolsky. M., "Energy", 1971, p. 106-107.

3. Fused refractory oxides. / Sokolov A.N., Ashimov U.B., Bolotov A.V. and others - M .: Metallurgy. 1988 .-- 232 p. S. 31-34, 77-82.

4. Magazine "Refractories", 1988, No. 7, p. 31-35.

5. Short networks and electrical parameters of electric arc furnaces. Ref. ed. / Dantis Ya.B., Katsevich L.S., Zhilov G.M. and others - M. Metallurgy, 1987 p. 143, tab. 3.11.

Claims (1)

A short network of an ore-thermal electric arc furnace for melting oxide refractory materials, containing rigid sections, both vertical and horizontal, bridges, fixed shoes spaced in height for different phases, flexible strings and contact jaws of an electrode clamping device, characterized in that a horizontal flexible string is used from fixed shoes to the contact cheeks of the electrode clamping device.

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