JPS58136978A - Method of preheating and melting material to be melted - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of preheating a material #+ to be melted, such as scrap or ferroalloy, using high-temperature gas in a melting furnace or smelting furnace.

In the conventional technology, as shown in a typical example shown in FIG. 1, a material 2 to be melted such as scrap or ferroalloy is completely charged into a container 1, and the combustion gas of a burner 5 or exhaust gas is introduced through an inlet pipe 4. Pre-heating gas such as high-temperature exhaust gas generated in a melting furnace (not shown) was passed through the inside of the waste material to be melted.

In this case, the upper opening of the container 1 is covered with a lid 6, and the gas outlet 6 of the high-temperature gas is connected to the container in order to flow the hot gas so as to distribute it evenly within the material to be melted and to obtain the best heat transfer condition. 6, and a high-temperature gas 'f for preheating was uniformly passed from the upper surface of the material to be melted into the interior without stagnation.

According to this method, high heat transfer efficiency can be obtained, so that it is useful for saving heat sources, but on the other hand, it has the following various problems.

Due to the necessity of providing the gas outlet 6 at the bottom, the container 1 uses a charging basket or a preheating cage or the like.

Therefore, in the next process of melting, the preheated material to be melted is
It is necessary to transport it from the preheating place to a melting furnace such as an arc furnace or a smelting furnace, and to transfer it there. First, this causes cooling during transportation and heat dissipation into the air during exchange, resulting in a large amount of heat loss in the material to be melted.

Secondly, when the material to be melted is transferred to the melting furnace, the material to be melted in a molten state may spill out from the bottom gap of the charging basket or the like, which is dangerous. Third, the fuming dust generated from the charging basket during transportation has a negative impact on the indoor environment.

The present invention is a method for preheating a material to be melted that eliminates all of the problems of the prior art as described above, and its feature lies in efficiently preheating the material to be melted in a melting furnace.

Embodiments of the present invention are shown in FIGS. 2 and 3.

A material 2 to be melted, such as scrap, is charged into a melting furnace 10 made of, for example, an electric furnace via a charging basket or a charging box Z. After charging the material, the entire bow melting furnace 10 is tilted about the horizontal direction with respect to the vertical direction by the rotation shaft 9 or other means.

In this case, the melting furnace 10 is tilted so that the side wall opening 11 provided above the hearth line is positioned downward, and the material 2 to be melted in the furnace is moved toward the furnace top opening 16. Melting furnace 10
The slope is adjusted so that the high temperature gas flows from the furnace top port 16 via the material 2 to be melted, between the side wall ports 11, and uniformly flows through the gaps between the material 2 to be melted. Depending on various conditions such as the shape of the melting furnace 10 or the material 2 to be melted, the melting furnace 10 may be tilted more greatly than that shown in FIG.
The melting furnace 10 is horizontally oriented, and the furnace top opening 16 is
As long as it is not completely blocked by solution material 2,
Tilt it so that it faces downward.

Next, the burner 5 or the high-temperature gas supply pipe 14 equipped with the high-temperature exhaust gas introduction pipe 4 is connected to the furnace lid 3, and the side wall port 11
The exhaust gas duct 12 is fully connected to the burner 5 or the high temperature exhaust gas introduction pipe 4 to supply the high temperature gas into the full melting furnace 10, and the exhaust gas duct 12 is connected to the furnace side wall port 11, and the exhaust gas is sucked from the exhaust gas duct 12. By doing so, high-temperature gas is passed through the material to be melted 2 to heat it to a desired temperature.

After preheating, the melting furnace body 10 is rotated to return to an upright state, and an arc melting electrode (not shown) is inserted from the furnace top port 13 to perform melting.

It should be noted that whether or not the flow of high-temperature gas in the material to be melted 2 is in a favorable state with no drift etc. can be confirmed by checking the furnace top port 13.
This is done by detecting the transition of the pressure loss that occurs between the side wall port 11 and the side wall port 11.

The method of the present invention has the following advantages: (1) The soil area of the material to be melted, that is, the area that comes into contact with the high-temperature gas, can be increased, and the material can receive high-temperature radiant heat transfer from the opposing furnace side wall. Therefore, heating efficiency is very good.

(2) Since the preheated material to be melted can be melted as is in the melting furnace, there is no heat loss due to replacement, and no replacement work is required.

As described above, the present invention completely eliminates various drawbacks of the prior art, and achieves higher heat utilization and improvements in safety, workability, and indoor environment.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the conventional method, and FIGS. 2 and 3 are explanatory diagrams of the present invention method. 1: Melting furnace 4; Exhaust gas pipe 7; Charging box 9; Rotating shaft 11; Side wall port 12; Waste gas duct 16; Furnace port

Claims (1)

[Claims] Preheating of the material to be melted, characterized in that the melting furnace containing the material to be melted is tilted, and preheating is performed by connecting a high temperature gas supply pipe to the top of the melting furnace and a waste gas duct to the furnace side wall port. Method.