JPH0227594B2 - HYOKAIZAIRYONOYONETSUYOKAIHOHO - Google Patents

Description

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

In the conventional technology, as shown in a typical example shown in FIG.
A material to be melted 2 such as scrap or ferroalloy is charged into the inside of the furnace, and the combustion gas of the burner 5 or high-temperature exhaust gas generated in another melting furnace (not shown) is introduced via the exhaust gas introduction pipe 4. Preheating was performed by circulating high-temperature preheating gas inside the material to be melted.

In this case, the upper opening of the container 1 is covered with a lid 3, and the gas outlet 6 of the hot gas is connected to the container in order to flow the hot gas evenly distributed within the material to be melted and to obtain the best heat transfer condition. 3, to allow the preheating high-temperature gas to pass uniformly from the top surface of the material to be melted into the interior without stagnation.

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

Because it is necessary to provide the gas outlet 6 at the bottom, the container 1
In this case, charging baskets or preheating cages may be used. Therefore, in the next step of melting, it is necessary to transport the once preheated material to be melted 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, leading to 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 molten material to be melted may spill out from the bottom gap of the charging basket or the like, which is dangerous. Thirdly, the smoke and dust generated from the charging basket during transport adversely affect the indoor environment.

The present invention is a method for preheating a material to be melted that solves the problems of the prior art as described above, and its feature is that the material to be melted is efficiently preheated 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, such as an electric furnace, via a charging basket or a charging box 7. Melting furnace 1 after charging material
0 is tilted with respect to the vertical direction with the horizontal direction as the axis 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 inside the furnace is moved toward the furnace top opening 13. The inclination of the melting furnace 10 is such that high-temperature gas flows from the furnace top port 13 through the material 2 to be melted and then to the side wall port 1.
1, and the material to be melted 2 flows uniformly through the gaps.

Depending on various conditions such as the shape of the melting furnace 10 or the material to be melted 2, the melting furnace 10 may be tilted even more than that shown in FIG.
Further, the furnace top opening 13 is tilted downward as long as it is not completely blocked by the material 2 to be melted.

Next, connect the burner 5 or the high-temperature gas supply pipe 14 equipped with the high-temperature exhaust gas introduction pipe 4 to the furnace lid 3,
In addition, a waste gas duct 12 is connected to the side wall port 11,
High-temperature gas is supplied into the melting furnace 10 from the burner 5 or the high-temperature exhaust gas introduction pipe 4, and a waste gas duct 12 is connected to the furnace side wall port 11, and by suctioning from the waste gas duct 12, the gas is introduced into the material 2 to be melted. A high-temperature gas is passed through and heated 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 without drifting or the like can be confirmed by detecting the change in pressure loss that occurs between the furnace top port 13 and the side wall port 11. conduct.

The method of the present invention has the following advantages.

(1) The upper area of the material to be melted, that is, the area that comes into contact with the high-temperature gas, is large, and the heating efficiency is very high because it receives high-temperature radiant heat from the opposing furnace side wall.

(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 there is no need for replacement work.

As described above, the present invention 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 introduction pipe, 7; Charging box,
9; Rotating shaft; 11; Side wall port; 12; Waste gas duct; 13; Furnace port.

Claims (1)

[Claims] 1 Tilt the melting furnace containing the material to be melted,
A method for preheating a material to be melted, characterized in that 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.