JPS61283444A - Heating element embedded gate of continuous casting machine for thin sheet - Google Patents

Abstract

PURPOSE:To eliminate the shell to be generated on the inside surface of a gate body and to permit smooth casting by using a detecting element and control device in such a manner that the heating elements consisting of graphite embedded in the gate body generate heat and executing temp. control. CONSTITUTION:The heating elements 13 consisting of graphite and a thermocouple 19 to detect the temp. of the heating elements 13 and near the inside wall surface of the gate body 2 are embedded into the bottom of the gate body 2. The thermocouple 19 inputs the detected temp. signal to the control device 24. The control device 24 automatically controls the quantity of the electric power to be supplied to the heating elements 13 by the signal form the thermocouple 19 to prevent the shell to be formed on the inside surface of the gate body 2 by local heating.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a weir in a continuous thin plate casting machine that continuously casts thin plates such as by-products.

Conventional technology In a weir where conventional thin plate continuous casting is also possible, in order to prevent shells from growing on the inner surface of the weir body, electromagnetic induction coils μ are installed around the weir body to increase the temperature of the water and melt it. There were some that rectified the current, or simply made the weir itself insulated.

Problems to be Solved by the Invention However, in the above-mentioned conventional configuration, high temperature or complete insulation in a local area was achieved through an internal cone, and the cost also tended to increase.

The present invention relates to a weir with a heating element embedded in a thin plate continuous casting machine which eliminates the above-mentioned conventional problems.

Means for Solving the Problems In order to solve the above problems, the heating element embedded weir in the thin plate continuous casting machine of the present invention has a fully heated body made of graphite at least at the bottom of the weir body, and a fully heated body made of graphite and the above-mentioned fully heated body. A detection element for detecting the temperature near the inner surface of the weir body is embedded, and a control device is provided to supply power to the penalty button heating element based on a signal from the detection element.

Function According to the above configuration, the temperature of the heating element made of graphite buried inside the weir body and near the basic IF surface is detected by the detection element, and the control device thereby controls the power supply to the ripe body. Therefore, the inner surface of the weir body is locally heated to a temperature higher than the solidification starting point of the melt (1519 degrees Celsius), and furthermore, for the sake of taste, an amount of heat greater than the amount of heat flowing into the weir body is supplied to a predetermined area. It is possible to perform smooth casting without causing irregularities in the flow of molten steel at the other end, and by eliminating shells generated on the inner surface of the weir body.

EXAMPLES Hereinafter, practical examples of the present invention will be explained based on FIGS. 1 to 12.

Figure M1 is a plan view of the main parts of a continuous thin plate casting machine equipped with a weir in which a heating element is embedded in a practical example of the present invention, and Figure 2 is a schematic longitudinal sectional side view of the same, in which (1) shows the weir, (2) ) is the weir body, (A) is the pouring nozzle μ that supplies the melt m (4) to the weir body (2), and (6) is the endless pot μ driven by the rollers (6) and (7).
This belt is made of metal such as copper. (8) (9) is a presser roller, (1
0 is the cooling box, and (b) is the 0 bend main body (jM′w4).
As shown in detail in Figs. 8 to 5, it is made of refractory material (b), and a heating element made of graphite is embedded inside. This heating element (goods) consists of eight rod-shaped parts (18a), two contact parts (18b) that connect these rod-shaped parts (18a), and an external part from the outer surface of the d-shaped main body (2). Two drawer parts (18c) protruding from the outside are connected in series, and the rod-shaped part +Lea) is housed inside the quartz glass W. This rod-shaped part (Hlm
) is the bottom of the weir body (2), and /@ a (4
), this inner surface C is located near the inner surface of the weir body (2a)
2a), and the quartz glass part 04 is arranged along
1! , approximately half of the weir near the outer surface of the weir body (2) is covered with fiber f.
It is covered with an A-quality heat insulating material 4, and approximately half of the side near the inner surface of the weir body (2) is covered with a monolithic refractory Me. A gas supply pipe for supplying argon gas is connected to the quartz glass pipe.This quartz glass pipe is sealed with a seal material made of powdered graphite. A plurality of thermocouples as detection elements are buried inside the ff1l weir main body (2), and the tips of these thermocouples are connected to the heating element 0 and the weir main body (2).
It is located near the box (2a). 91 is an adhesive.

The inner surface of the Buki weir body (2) has a small surface roughness and is easy to peel off even if a thin layer is formed. A gap is provided to prevent heat from flowing from the refractory (b) of the weir body (2) to the pipe (5). As shown in detail in Fig. 6, the terminal (2) is connected to each drawer (18c), and this terminal is connected via a relay terminal by a conductor (2). It is connected to the power output terminal of the control device t-.

This control device has an AC power supply (E) connected to its input terminal via a conductor (to), and the thermocouple α is connected to its signal input terminal. This control device (foundation) can automatically control the power supply to the heating element (6) based on the signal from the thermocouple a, and at the same time, although not shown in the figure, the control device can automatically control the power supply to the heating element (6). It is equipped with a display and allows manual control.

To raise the temperature of the inner surface of the weir body (2a), as shown in Figure 7, first start preheating at point A, gradually heat the burner (not shown) for several tens of minutes, and then turn on the burner at point B. Heating at the maximum capacity of the preheater and increasing the rate of temperature rise.At this time, the temperature is constantly monitored using the thermocouple (2).Next, when the temperature rise during this preheating begins to asymptotically approach, that is, at point 6. energize the heating element (2) and gradually raise the monitored temperature.When the monitored temperature reaches about 1600℃, start pouring at point D and adjust the temperature accordingly. After an hour,
Start casting drawing.

By the way, low voltage, Ai, is applied to the heating element made of graphite.
When a current is supplied, the temperature at the center reaches a maximum of approximately 2600°C.
, the surface temperature is raised to about 1800°C or more. The temperature of this heating element (2) [! The field is controlled by a thermocouple. Graphite is oxidized and consumed at high temperatures, so cover the rod-shaped part (IJla) of the heating element with quartz glass WQ41, seal both ends of it with sealant (18a), and seal the rod-shaped part (18a). An inert gas such as argon is appropriately supplied through the gas supply pipe (b) to such an extent that the surface temperature does not drop. The rod-shaped part (18a) has a very small cross-sectional area compared to other parts (ζ), so it has a large resistance and becomes high temperature.The thermoelectricity generated on the heating element side is thus transferred to the weir body (2) of the rod-shaped part (18a). ) Approximately half of the side near the outer surface number ζ is covered with heat insulating material (to), so the inner surface of the weir body (
Most of the refractory material (2) flows to the 2a) side, and the refractory material (2) in this part is heated uniformly to a high temperature quickly.

In this way, after pouring the metal into the weir body (2), by keeping the surface temperature of the refractory (6) above the melting temperature and further supplying heat to the weir body (Fig. 8 (A)). As shown in FIG.
As shown in Fig. 8 (C), there is no occurrence of constraint shells), so stable continuous casting can be performed, and at the same time, the shell thickness at the beginning of the shell can be suppressed, so the slab The depth of surface cracks is suppressed and quality is improved. In addition, since the target area to which heat should be supplied is local, the absolute amount of heat to be supplied is small, and the energy density of graphite, which constitutes 1aIII4, is high, so it is easy to increase the temperature of refractories. can bring. Furthermore, the device is compact and can be used to shorten preheating time using a burner or the like.

Figures 9 to 1 show another embodiment, and this embodiment is an example of a twin roll type thin plate continuous casting machine, in which Figure 9 is a plan view, Figure 10 is a hemostatic diagram, 11 is a sectional view taken along line MM in FIG. 9, and FIG. 12 is a sectional view taken along line ``-■'' in FIG. 9. In Figs. 9 to 12, (b) and (to) are rolls, so is the weir body, and (to) is a heating element made of graphite. A force S1 (not shown) and each heating element (2) are controlled by conductive wires. connected to the power output end of the Furthermore, a thermocouple is embedded in the weir body (in the weir body), and the two thermocouples are connected to the signal input terminal of the control device. In this embodiment as well, the same effects as in the previous embodiment can be obtained. Note that the steel strip is pulled out downward from the gap between both rolls (b) q.

In each of the above embodiments, a thermocouple was used as the sensing element, but it goes without saying that other temperature sensing elements may be used.

Effects of the Invention As described above, according to the present invention, the heating element made of graphite embedded in the weir body is made to generate heat and its temperature is controlled using the detection element and the auxiliary device. It is possible to prevent shells from forming on the inner surface of the weir body due to heating, thereby achieving energy savings, compactness, and long life, and allowing stable continuous casting over a long period of time. Furthermore, since the thickness of the shell at the time of birth can be suppressed, the depth of cracks on the slab surface can be suppressed and quality can be improved.

[Brief explanation of drawings]

1 is a sectional view taken along the d-α line in FIG. 8, and FIG. 5 is a sectional view taken along the Y-VAI line 8 in FIG. Figure 6 is a schematic overall configuration diagram of the weir with embedded heating element, Figure 7 is an explanatory diagram of the temperature rise curve of the inner surface of the weir with embedded heating element, and Figures 8 (A) to (C) are the weir with embedded heating element and An explanatory diagram of the growth state of shear μ in a conventional weir circle ml, FIG. 9 is a plan view of a thin plate continuous casting machine equipped with a heating element embedded weir in another embodiment 1, and FIG. 10 is a front view of the same. , FIG. 11 is a sectional view taken along the Xia-M line in FIG. 9, and FIG. 12 is a sectional view taken along the Xl-31 line in FIG. (2) (To)...Weir body, ring (B)...Heating element, 4...Thermocouple, (Foundation)..., [-device

Claims (1)

[Claims] 1. A heating element made of graphite and a sensing element for detecting the temperature near the heating element and the inner surface of the weir body are buried in at least the bottom of the weir body, and a signal from this sensing element is used to supply power to the heating element. A weir embedded with a heating element in a continuous thin plate casting machine, characterized by being equipped with a control device for controlling supply.