JPS6049849A - Device for supplying mold cooling water for horizontal continuous casting - Google Patents

Abstract

PURPOSE:To prevent the danger of dew condensation by using two lines, a supply line for hot water and a supply line for cooling water for supplying the cooling water to a mold and changing over automatically the supply of the hot water to the supply of the cold water according to the temp. detected with a temp. detector provided in the wall part of the mold. CONSTITUTION:Electricity is conducted to a heater 24 which heats the water in a hot water tank 25 to 40-100 deg.C. The hot water is circulated into a mold 1 by opening valves 29, 32, closing valves 20, 14 and starting a pump 27. The heating up in the mold 1 is checked with a temp. detector 38, then the installation of a break ring 4, connection of the mold 1 to a tundish 2 and insertion of a dummy bar are performed. A molten metal is then poured into the tundish 2 and the inflow into the mold 1 is detected with the detector 38. The valve 32 is closed and the valve 20, 14 are opened by the signal from said detector to circulate and pass the cooling water from a cooling water tank 12. Continuous casting is thus executed in the stable condition.

Description

[Detailed Description of the Invention] The present invention is a mold for preventing explosion phenomena and other types of tofu caused by the reaction between molten steel flowing into the mold at the start of casting and condensate water in a horizontal continuous casting equipment R. Gate to cooling water control supply system.

In horizontal continuous casting, a mold with a water-cooling jacket is directly connected to the side of the kundish, and the molten steel flowing into the nozzle 'tip mold of the tundish from one end is indirectly cooled to form a solidified shell and converted into a slab at the other end. In order to accomplish this process, the molten steel flows from the inlet end of the mold to the desired position of the flow into a solidified shell shape bj! ,'t-It is a formality to start.

It is desirable that the mold has a water cooling capacity of 1J (a large L car with good controllability).

By the way, in order to cast +11[]Db, the tundish is preheated and a dummy bar with a tip of the slab IJI is inserted from the other end of the mold. In horizontal continuous casting, the inside of the mold is closed, and the water vapor in the tundish preheating exhaust gas flows through the water-cooled mold and the mold.

The cold rL condenses and remains as water due to the mee bar,
When the molten I4 flows in, the VC molten steel and anti-SL may cause an explosion phenomenon, blowing up the molten steel in the tundish. As one of the measures in Section 7, it has been proposed to allow cooling water to flow through the mold when preheating the tanditsu.
The timing with the start of fi must be made at a very delicate η timing, and this is accompanied by a sudden change in temperature, so there is a high risk of an accident.

The present invention has been developed to solve these problems, and is a mold cooling water supply device for horizontal continuous casting that does not cause water condensation in the mold during preheating of the tundish. Directly from the ML tundish, the nozzle provided on the side wall is bent to cool the melt in the mold.
In a horizontal continuous casting machine that horizontally pulls out 1 clJ+ of slabs that form shadows, cooling water is supplied to the mold from a hot water tank equipped with a temperature raising device, and a hot water supply system with a temperature of 40°C or more and less than 100°C and a low temperature one. There are two lines for the cooling water supply system, and a temperature control device is installed on the mold wall so that the mixed water supply can be automatically switched from the mixed water supply to the cold water supply depending on the detected temperature. Features.

For the same purpose, heating the mold externally is
In general, the jacket and needle cooling channels in the mold of horizontal continuous casting are constructed in a complicated manner, and because of the horizontal arrangement, it is extremely difficult to ensure that there is no accumulation of cooling water. There is a risk of a steam explosion as it is necessary to provide a mold pulley that can withstand the generation of heat.Furthermore, QIJ rings with a heat resistance of around 100°C are often used as seals inside the mold, so they are susceptible to burnout due to external heating. Water leaked inside the mold! There is also a risk of an explosion occurring.

Hereinafter, the present invention will be specifically explained in detail with reference to the accompanying drawings. FIG. 1 rI'i An embodiment of the present invention is shown in a system diagram.

The horizontal continuous casting mold (1) is Tanditshu (2)
The feed nozzle (3) enclosed in the side wall of the tundish (2) is directly and fixedly connected via the break ring (4), and is injected from the ladle (5) into the tundish (2).
(6) passes from the nozzle (3) through the plate ring (4) to the mold (within 1 inch). Mold (1) I'i
In order to start solidification by indirect heat exchange and water cooling heat removal from molten steel and make it into a slab (7) that can be drawn, a water cooling jacket (8) is provided. As a source of cooling water that is designed to carry out circulation circulation, a relatively Yamato cooling water source is used because it enables rapid and continuous heat removal of a large amount of heat from the copper in the mold (1). The hot water from the outlet αQ of Kumold's water cooling jacket, which is generally used for the cold water receiving tank (b) of the heat exchanger, is supplied by stop pulp □□□ and electric fishing pipes. The water returns to the cooling tower QvK through the Shun flow tube 10 having α~, where it dissipates heat and becomes low-temperature cooling water, which collects the cold water m(b)K, from which it passes through the filter 4.

Stonpa Pulp α's It & Water Pump (7), Nagetsu Total 4.

KL so that cooling water is fed to the inlet (9) K through a supply pipe line having a check valve φV and a stop valve □□□ and circulated through the jacket (8).

It will be used as a supply line for low temperature cooling water.

In the present invention, in addition to the cooling water supply line, a temperature raising device Q4 is provided.
Equipped with a hot water tank (with a relatively small amount of water), from there to a filter), a water supply pump), rl1m
Meter (to), electric 17J exchange valve 4, check valve -.

(8) K supply pipe 745 to cool leakage water of 40C or more and 100℃ through the above-mentioned stop valve.
t81) is provided. From the outflow opening to the stop valve), branch from the pipe (to) L 11 #J VJ exchange (to the hot water tank via 82) K return pipe lIi!
1CAB).

(34) is the cooling water supply route for IP Tomikawa, and the pressure drop (81) occurs in the water supply route to either mold. pressure switch (85) in the event of a power outage.

The emergency cooling water pulp (
87) Open it so that cooling water can be supplied to the mold from an elevated tank (not shown).

In the present invention, a temperature detector (88) consisting of a temperature measuring thermocouple is provided on the mold wall, and the seven detection signals are sent to a converter (39).
vc send C, -tt'LK! Riden'flJ Yukan Valve α0I (
82). The converter (89) also serves as a temperature indicator. (40X41X42) indicates a thermometer.

The apparatus of the present invention having the above configuration is operated in the following order.

(+) Energize the temperature raising device (c) to raise the temperature of the water in the hot water tank to 40°C or higher and lower than 100°C. The temperature and level of the certificate in the hot water tank are automatically controlled to maintain a constant level.

(1) Electric switching valve @ C82) is enclosed, Trout) 1.1I
tl is closed and the water supply pump @ is started to circulate and warm the hot water inside the mold (1).

(2) Temperature detector (88) After confirming the temperature rise status of mold and de from K, disconnect plate ring (4), connect mold (1) to evening/dish (2), and insert dummy par. The dummy par is heated by hot water circulating through the mold (1).The preheating of the tundish continues during this time, and dew condensation inside the heated mold (1) is completely prevented.

It is preferable that the dummy par is heated beforehand outside the mold (1) to absorb the force; however, in the case of a small cross section, it may be left as is.

([V) After completing the casting preparations as described above, ideally after 5 minutes after installing the dummy par, pour the molten steel from the ladle (5) into the tundish (2)09) Molten steel mold (
1) The temperature sensor (88) automatically detects the inflow into the interior, and the electric switching valve 0!1 (82) 't is activated based on the signal.
- Close the power supply 11IJ switching valve) and open the cold water 1W (
2) Perform continuous casting in a stable state by circulating low-source cooling water from 2) As a result of experiments, 60 to 80 degrees Celsius is a good setting temperature for hot water due to the risk of condensation and cavitation problems in the water supply pump. I understand.

In Figure 3 0), the horizontal axis shows the time opening and the vertical axis shows the flow rate.

Change in flow rate of hot water (force and change in flow rate of low-temperature cooling water (Y)).As shown in the figure, the supply of low-temperature cooling water is started 5 to 10 seconds before the hot water flow is stopped, and the hot water flow is stopped. If the water flow is overlapped so that the low-temperature cooling water reaches the full IJtl flow state, the water flow temperature to the mold jaunt will change as shown in Figure 3 (b) with temperature on the vertical axis and time on the horizontal axis. As for the balance between the pressure and water volume of hot water and low-temperature cooling water, if the pressure is the same, the Ef! Vc for easy and smooth switching.

As described above, according to the present invention, hot water of 40°C to 100°C is poured into the mold jacket until the start of casting to raise the temperature of the mold. It also prevents condensation. Furthermore, since there is no sudden temperature change in the PC when the molten M is inserted, the strain that occurs in the mold can be reduced, so the chances of water leakage due to mold distortion can be reduced. In addition, by raising the temperature of the mold to an appropriate temperature before storing it, it is possible to reduce the amount of pressing ii of plaque rings, etc., making it easier to manage them. Furthermore, by providing a temperature detector on the mold wall to detect when molten steel flows in, it is possible to easily switch between hot water and low-temperature cooling water.

The present invention can also be operated to maintain the temperature of the cooling water supplied to the mold during continuous casting at a desired separation by merging hot water with low temperature cooling water. A system diagram of the embodiment is shown, and parts equivalent to those of the embodiment of FIG. In the embodiment shown in FIG. 2, in addition to the humidity IRm detector (88) on the mold wall, a low-temperature cooling water sensor (48) is provided in correspondence with the hot water humidity detector (40).
X43XD detection water temperature signal converter and calculator (39A)
By inputting the input into It can be controlled to force.

These temperatures are detected by a temperature detector (4υ (42)) and input as control data to a conversion and calculation m (89A).

The cooling water inlet temperature can be controlled to be always constant at an optimum value of, for example, 80°C as a set value, and this optimum temperature is determined by the temperature from the molten steel temperature sensor (44) and mold wall temperature sensor (88) in the tundish (2). It can be determined by converting the detected temperature ## as data and inputting it into the calculator (89A). In continuous casting, as mentioned above, in many cases, cold water from a water cooling tower is used as cooling water for the mold. Since a water cooling tower cools most of the hot water using the large latent heat generated by the evaporation of a portion of the hot water, the temperature of the cold water changes depending on the humidity of the outside air. In general, cooling towers are equipped with R under outside air conditions in the summer, and there is a tendency for excessive cooling to occur in the fourth period, so if the mold cooling water humidity becomes too low, there are many cases of 2.Especially during long-term cold weather or after holidays, Temperature is low. kot'
For LVc, in the example shown in Figure 2, convert the data of the hot water temperature in the hot water tank and the low temperature cooling #iA degrees from the water cooling tower, and input the VC to the calculator (89A), -1
Here, by controlling the mold cooling water inlet temperature R to a specified value, it is possible to carry out continuous manufacturing under fixed conditions.

If the temperature of the molten steel inside the tundish and the temperature of the mold wall are controlled so that the inlet and outlet temperatures of the cooling water are kept constant, the continuous casting situation will be stabilized and slabs of excellent quality will be produced. Obtainable.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of one embodiment of the device of the present invention. FIG. 2 is a system diagram of another embodiment of the device of the present invention. Fig. 8 (/4) is a diagram showing changes in the amount of water rlIL, Fig. 8 (b) shows ... feed nosing, and (4) ... plate ring. (5) - Life - dollar, (6) - Molten steel, (7) - Slab, (8) - Fist water cooling jacket, (9) - Inlet, a
n・-Outlet, C1l・・Water cooling tower, (B)・φ cold water tank, 0α force (4)・・Stop pulp, 114011
@ (82)... Electric # switching valve, OQ... Return flow pipe, Q
I (c)...7 ri~, (to) ni)...Water pump, (
6) (c)...Flowmeter, Qηso...check valve, @...supply pipe line, (c)...temperature raising device, (c)...hot water tank, (
81)... Supply pipe line, (8B)... Return pipe line, (8
4)...Emergency pipe, (85)...Pressure switch y+, (8
6)...<40t valve, (87)...Emergency n+ pulp, (88)...Mold wall temperature detector, (89)...Converter, (89A) --Conversion and computing unit, ( 40)
(41) (42) (4B) (44) --M degree detector, (X) (Y) --@ii curve.

Claims (2)

[Claims] (1) Directly connect the mold to the side wall of the tanditsh, and pass the V inside the mold from the tanditsh to the nozzle provided on the side wall.
In horizontal continuous casting rAVC, in which the cast R formed by cooling the inflowing awn melt F14 is pulled out horizontally, cooling water is supplied to the mold from a hot water tank equipped with a temperature raising device.
There are two lines: a hot water supply line with a humidity level of 100℃ above ℃ and a low temperature cooling water supply A W6, and a temperature sensor is installed on the mold wall to automatically switch from hot water supply to cold water supply according to the detected temperature. A mold cooling water supply device for horizontal continuous casting, which is characterized by being able to supply water by switching VC. (2) The water in the hot water supply system and the low temperature cooling water supply system can be combined to supply water to the mold. A mud water humidity detector 2 and a low-temperature cooling water temperature detector are arranged together with the mold wall qML temperature detector, and depending on the detected temperature, each of the bush water supply system line and the low-temperature cooling water supply system line 11111 is connected via a converter. The mold cooling water supply device for horizontal continuous casting according to claim 1, characterized in that the humidity of the combined water at the cooling water inlet of the mold is adjusted to a desired value by adjusting k IIJ it'.