JPS5947054A - Method for preventing blockage of nozzle part for discharging molten metal - Google Patents

Abstract

PURPOSE:To prevent the sintering of packing materials in a lower layer and to smooth and stabilize the operation for treating molten metal by packing the granular packing material of a high m.p. in the lower layer of the closed nozzle in a charging nozzle part in the bottom of a vessel for molten metal and the granular packing material of a low m.p. in the upper part thereby forming a foamed and expanded heat insulation layer in the upper layer when the molten metal is contained in the vessel. CONSTITUTION:A granular packing material 5 of a high m.p. having m.p. exceeding the temp. of molten metal as a preventing material for clogging is packed in a sliding nozzle SN in a closed state up to the top end of the nozzle hole of the upper nozzle 3 theeof. A granular packing material 6 of a low m.p. which foams and melts at the temp. lower than the temp. of the molten metal is packed into the expansion nozzle hole of a nozzle rest brick 4 supporting the upper nozzle 3 up to the inlet thereof in succession to the above. The material 6 for which feldspar or the like is used is granulated to <=2.0mm. grain size and is put in a PE bag which is charged in the nozzle hole. Then a semi-molten film 7 and a foamed and expanded heat insulation layer 8 are formed on the surface of the packing material 6 by preheating or the heat of the molten metal, by which the sintering of the material 5 is prevented. When the upper nozzle 3 is opened, the unfoamed part 6 of the material 6 flows down then the layer 8 collapses and flows down, thus flowing from the nozzle hole together with the molten metal.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing blockage of a bath water pouring nozzle portion provided at the bottom of a molten metal container such as an unloader 41 or a tundish.

In general, the bath water pouring nozzle section installed in a ladle 1 or tundish, etc., is composed of a sliding nozzle device consisting of an upper nozzle, a fixed plate, and a sliding plate, and a lower nozzle, and a sliding nozzle unit consisting of an upper nozzle, a fixed plate, and a sliding plate. By doing so, the outflow of the bath melting area in the ladle can be adjusted or stopped. However, when installing a sliding nozzle device and press-fitting molten metal into a ladle or tactile nozzle, even if the inside of the container is preheated, it is not sufficient, so the temperature of the molten metal must be lower than this temperature in the upper nozzle of the device and the fixing device. It flows into the nozzle hole of the plate and is cooled and solidified. Therefore, even if the nozzle was opened by sliding the sliding plate, there was a problem in that the molten metal could not flow out.

For this reason, in the past, slitting, graphite with a melting point exceeding the bath water temperature, natural silica sand, wood shavings, iron oxide powder (
Prevents molten metal from entering the nozzle hole when the mill scale is filled with blockage, prevents molten metal from entering the nozzle hole, and prevents blockage when the nozzle opens, preventing the bath from falling with the molten metal. I was trying to do that. However, with the advancement of casting technology, when the time required for the molten metal to flow out from the ladle is long, or when the heating technique of the bath melting pot is still lacking, the conventional method is used. The group closure prevention phase 1 may float on top of the molten metal or sinter and solidify within the nozzle hole, making it impossible to fully absorb the effect.In such cases, an oxygen lance is used, which is extremely dangerous to work with. Then, the molten metal in the ladle had to be flowed out by melting the blockage prevention interest that was 1p3rl b'=1.

In order to improve this drawback, the applicant of VC1 previously published a Japanese Patent Publication No. 55-181.94 to improve the grain size from 0.5 to 2.511111.
1) and characterized in that the main component composition is 5i02i80-94% by mass, alkali, 2-12% stone, and 1)-- when the nozzle hole is clogged. did. However, when the melting point particulate sludge is charged, a part of the sludge is washed away by the bath water flow and floats on the top surface of the bath water, causing the molten metal to flow into the nozzle hole. If the bath water stagnates for a long time due to penetration solidification or waiting time for pouring out the bath, the light filling or sintering will solidify in the nozzle hole, resulting in Before starting to pour out bath water, press the sliding plate 1.
31. Even if the nozzle hole was opened, it became impossible to pour out the molten metal, and all the hole opening work was done by acid washing, etc.

This will all be explained with reference to FIG.

In the figure, the left half view is a side cross section showing the state immediately after filling, and the right half view is a side cross section (not shown) in state 4, immediately before the nozzle hole is opened, after a certain period of time has passed after charging the molten metal.

As shown in the left half figure, the high melting point granular filler 5 forms the nozzle hole on the sliding plate 2 in the closed state, and the two-part nozzle 3 and the nozzle receiver/gauge 4 that support this. Filled up to the top of the inlet. 7, and when the molten metal is charged, a part of the filling material is washed away by the 1♀ bath water, floats to the top surface of the bath water, and becomes the filling material 5 as shown in S○ in the right half figure.
The sum of decreases. In this state, if the water has been kept in IHJ for a long time due to waiting for pouring, etc., it will begin to sinter from the surface that comes into contact with the bath water, and a hard solidified layer will form inside the nozzle hole. Gr shadow formation and occlusion state. For this reason, I'm
Even if the nozzle hole is opened by opening the plate 2'tL, the unsintered part will only fall in the molten metal, and the collapse of the solidified layer G due to the static pressure of the molten metal will be delayed or impossible, and the enemy will be washed away. It is extremely difficult to pour out molten metal that requires .

The continuous uQ'ty, i-zukuri-Rinnobe direct connection process, which has been proposed in recent years and has been put into actual operation, is a series of continuous molten steel melts of several charges.
The aim is to stabilize the quality of the slab and save energy by continuously casting the slab and supplying it almost continuously at high temperatures to a number of uses. 14! Excluding I/C for changing the ladle: ・Nosurui L where the pouring point of the ladle is as above.1. &'1 If the start of production is delayed, the surface of the slab may be affected due to abnormalities such as a drop in molten metal and a drop in casting speed. And internal defective light will cause heartbreak. Father, the corresponding eye] The cancellation VC of the base state is! III Generally speaking, oxygen lance is used for sintering to prevent group closure, and the bath is melted and the bath is removed. I have lost a lot of money and my dignity has deteriorated.

In either case, the implementation rate of the direct process will be reduced. Therefore, in the direct connection process, it has been desired to develop a method for preventing clogging of the pouring nostle hole, which has an even higher instantaneous pore opening rate.

The present invention was made in response to the demands of this new era and to solve the above-mentioned drawbacks. □The present invention is characterized by the fact that it is installed at the bottom of the bath water container before pouring the bath water. 7 In the molten metal pouring nozzle part consisting of a nozzle brick and a slitting nozzle, the lower layer inside the nozzle hole of the upper nozzle brick above the sliding nozzle which is in the closed state is filled with a granular filler with an interval melting point having a melting point exceeding the temperature of Minatoyu. , the upper layer is filled with a tray of low-melting point granular filler that foams and melts at a temperature below the bath water temperature, the low-melting point granular filler is Δ and C is feldspar, and the particle size of the low-melting point granular filler is k2. ．． Oftun
Hereinafter, the process of VC is to place the low melting point M-shaped filler 4 in a polyethylene bag in advance and charge it upward into the nozzle hole.

That is, the low melting point filler in the &C of the present invention forms a semi-molten film on the surface layer when preheating the molten metal container or comes into contact with the charged molten metal, and is itself washed away by the molten metal. In addition, a heat-expanded heat insulating layer is formed directly under the semi-molten coating to reliably prevent the high melting point particulate filler from sintering and solidifying, and maintain its fluidity.

This allows the molten metal to be stored in the molten metal container, and when pouring out the molten metal,
By simply closing the sliding plate for opening and closing the nozzle hole, the entire amount of the high-melting point granular filler can be smoothly dropped and discharged, and at the same time, the fragile heat-insulating layer of the low-melting point granular filler that has been expanded by heating is easily removed by the static pressure of the molten metal. It disintegrates and falls and is discharged together with the molten metal, thereby ensuring instantaneous porosity of the nozzle hole. Therefore, the layer thickness of the low melting point granular filler is determined by the fact that the semi-molten film layer formed on the surface by contact with the molten metal melts away over time and ranks downward, and this turns into sweat and causes the heat insulation 51 to deteriorate. Due to the heat insulating effect of one body, it moves downward while maintaining r')r>l float. The layer may be filled and formed in advance on the high melting point granular filler layer with a thickness depending on the time and the rate of descent of each layer.

Hereinafter, the present invention will be explained in detail using FIG. 2.

In Fig. 2, the left half view is a side sectional view showing the state immediately after filling the anti-occlusion material before charging the bath water, and the right half view shows the state after the bath water is made.
It is a side view which shows the state before a nozzle hole opening surface after a certain period of time has passed.

In the left half diagram, the high melting point granular filler 5 as an anti-clogging material is filled in the nozzle hole at the upper end of the upper nozzle hole, and the upper nozzle hole upper end 1 of the upper nozzle 3 is filled with this, and the three upper nozzles are supported by this. The particulate filler 6ff with a low melting point is filled up to the artificial part' of the expanded nozzle hole of the nozzle receiver 4.

In the right half diagram, preheating before charging the bath water or heat of the molten metal at the time of charging softens the surface of the upper grain layer to form a semi-molten coating layer 7, which is different from the conventional method. This prevents the anti-occlusion material from being washed away due to the rσ flow. The melting point of the low-acid 1) point granular filling material 6 is about 300°C above the bath water temperature because it is necessary to instantly form a semi-melted odor layer due to the heat of the molten metal when charging the molten metal. Preferably low.

On the other hand, forming this semi-molten film in advance by preheating before charging the bath water is an effective means to prevent blockages caused by the flow of molten metal when charging the bath water, and to prevent leakage. In this case, the melting point of 1g'6 (low melting point granular filling) may be a temperature necessary and sufficient to form a semi-molten coating layer by preheating YM expansion. For example, when the preheating temperature is about 1200°C, the melting point of the low melting point particulate filler is about 1100°C, which is enough to form the semi-bath molten group layer. In addition, the low 1 carp point granular light filling 4) j6 is the lower side sound of the packed layer ^ Melting point granular filling phase 5
is in contact with the upper surface of the packed bed to inhibit heat transfer from the lower surface side.
Because it is illuminated, it depends only on heat transfer from the top side.
At the same time as the formation of the semi-melted coating layer, a heat-expanded thermal insulation layer 8 of a predetermined thickness is formed on one side of the semi-melted coating layer 7.
This suppresses the heating of the high melting point granular filler 5, reliably stops sintering, and maintains its fluidity. When the semi-molten coating of the low melting point granular filling layer 0 melts and floats over time and progresses to the heat insulating layer 8, the heat insulating effect corresponding to its thickness decreases, and the heat insulating layer 8 increases by that amount. Additional formation occurs below. For this reason, the heat insulating layer 8 does not reach the surface layer of the low melting point granular filling layer 6 through a deep groove and becomes extremely thick, but always maintains a thin thickness.
, the function of temporarily collapsing due to the static pressure V of the molten metal when the nozzle is opened when pouring out the molten metal as well as preventing sintering of the high melting point granular filling A-5? : To be maintained. Furthermore, the filling position of the low melting point granular filling layer t) into the nozzle hole on the finger plate 2 is the same as the heat insulating layer 8.
The upper nozzle 3 (/J J two ends and -) is formed in an upper wide shape in order to prevent the collapse of the nozzle easily and securely. It is preferable to increase the diameter of f thermal layer 8.

Therefore, even if the high-melting-point granular filling month 5 is stagnant for a long time due to waiting for pouring, etc., the state immediately before pouring the molten metal is as shown in the right-hand half diagram 1jC of FIG. ;H: Without sintering, it maintains the same flow inertia as shown in the left half of Figure 2 immediately after filling the tube ζ, and when the nozzle hole is opened by the opening operation of the sliding plate 2, it flows down instantly .

At the same time, the unfoamed portion of the low melting point granular packed bed 6 flows down.
Subsequently, the heat insulating layer 8 is exposed to the static pressure of the molten metal and collapses, causing the molten metal to be discharged from the nozzle hole at the mouth of the nozzle, making it clear that there are no blockages.

The high point granular filling materials used in Nejira Ming include well-known graphite, iron oxide (mill scale), and natural silica sand.

Alternatively, the particle size 05
~" 5nod, and the main component composition is 5i02 80-94% and alkali 2-12%.
- Is it possible to use a cheap light filler that contains a % temple?', If
'', kL, 1゜In addition, as for the low melting point granular packed bed, it is cheap - C easily manned 1 (for example, bath
13oC.

1 Feldspar (i'+a20.:5A1.203.BBIO2) which thermally expands when heated7 and forms a foam-like crow basin at a rate of 4 earthquakes/m-hr L. , barium feldspar (BaO-A4203.28102) Tsukasa J:
Feldspars such as feldspar (K2O.At203.6S i O2) and anorthite (Ca, 0-AI-203-28IO2) are preferred. Also, the roughness is preferably 2.0wn or less.

This is because when the nozzle hole VC is charged, the foam expands into the nozzle hole with a uniform thickness and has a good filling state, and the melting rate of the foaming bath is due to contact with the molten metal or preheating I/C. In order to advance uniformly toward the VC, it is possible to easily set the minimum required layer thickness of the low melting point granular packed bed according to the waiting time from the start of molten metal storage to the start of pouring. .In addition, when inserting the VC into the nozzle hole of the granular filler with a large melting point or low melting point, a film made of a burnable material such as polyethylene is prepared in advance.
In addition to the cost, it is packed in a bag or wrapped for ease of handling, and the three-way injection impact to the nozzle hole and heat reception from the surrounding area, etc.
(11 o'clock (') It is preferable to make it possible to open the grip naturally.

Next, an embodiment of the present invention will be described with reference to FIG.

Example 1 In order to prevent the nozzle hole Fjl from clogging in this example VL, first, silica stone with a particle size of 1.0 mm (weight ratio: 98 cm) was used.
'10% and particle size 1 length 'I:J30%,
Composition ratio is 1”-? S 10286 '36
r A 4034.5% + K200, '70%,
N201-5% r Fe2O30,6%, ca
o (Melting point of J3 thread, MgO 0.1% sword) 70
0℃ melting point granular packing material 9 with thickness of 0.05 unn
Prepared in a polyethylene bag with a melting point of 1100 °C.
, heat transfer coefficient 0.40 &al /rn -hr-℃, -
When heated at t, thermal expansion 11i <L' pin-shaped glass layer (insulating layer) sound formation'' grain size 1・01111+1 Put it in a polyethylene bag with 0.05111111 -
I prepared it.

Therefore, as shown in FIG.
Force Vc Sequentially installed fixed platen vertically 1. Sliding plate 2. Lower nozzle 1
The above aF is preliminarily inserted into the nozzle hole of the upper nozzle 3 of the slide inogutsle device S N and the fixed plate L.
fB point granular filling 9. Filling by three-way loading. Next, the above-mentioned low melting point granular filling paulownia 10 is filled into the expanded inlet of the nozzle receiving brick 4 in the second part by inserting the upper blade of a vinyl bag.

Next, the COG ladle preheating device preheats the ladle for 0 to 15 minutes until it is loaded into the bathtub. After that, molten Japanese maple at a temperature of 1620°C is poured into the pronged ladle RD at a temperature of 340°C.
Pour 110 minutes into the melting pot and leave for 10 minutes.
After opening the nozzle hole by moving the slide plate 1, we measured the instantaneous bid opening rate as shown in Table 1.
Excellent yield of 96%. (N=300ch)
The specific softness ν1 in Table 1 means that the above-mentioned still-melting-point granular filling phase 9 without using the low-melting-point optical filling layer 10 of this example is the fixed plate shown in FIG. 6') 77'1' Near (internal guest 'lj') i!Q I L, ) part nozzle 3 (7 nozzle hole and nozzle receiving brick 71L/) Fill inside the expansion inlet part 2, and other conditions 'Double-
This is a 1ll11 constant result when the condition is set, and 5%.
The instantaneous open area ratio was very low.

Example 2 As the nozzle blockage prevention phase in this example, glue f0, 5
~2.0 +l1%l natural silica sand (S i L129
B, CI 2 % 7 + Ip (J3 (upper 9 5
z + F'e2030.8 a %
, UaU Il, l 4 ya +R
20(,1,(i IJ %, melting point 1 'i' 80
+1% l+t'lt point granular filling month 9 consisting of U J
``Thickness is 111.1% as shown in ``Put it in a 105 mm horico resin bag and put it in the third container as in Example 1.''
-1 part of the nozzle hole of the nozzle 3 is filled, and then part of the nozzle receiver is filled with the melt in the expanded inlet part of the nozzle receiver 4
lf point 1200'C2 heat transfer 4i4' = 054 Va
/fn ・hr ・℃And when heated, it thermally expands and generates r
'The particle size that forms a film-like glass layer is 0. '7 nnn
+ Moisture 0.4 strength feldspar granular filling with low melting point 10 months
It was placed in a polyethylene bag with an ij speed of ○05 mm and filled by upward charging.

Next, under the same conditions as in Example 1, preheating and pouring into the bath 1 tank, and allowing it to accumulate for 20-11.0 minutes, the nozzle hole was opened by sliding the moving plate 1. When the instantaneous 1j1'' porosity sound was measured, favorable results of 100 to 95% were obtained as shown in Table 2. The specific soft seri 2 in Table 2 is the low-melting point granular filling material 10/- of this example, and the above-mentioned melting point granular filling material is not used, and only the filling material 9' is the hard-footed seri shown in FIG. 3. The nozzle hole of the two-part nozzle 3 and the nozzle receiving brick 4 are expanded to fill the inside part.
The result of '611 in case of shell-C was that the instantaneous pore opening rate was 94% or less. In addition, the relative softening 113 is shown in Figure 3.
：の、j11′□：(Zo%1.l in the inner mouth!、'：j：
l-,) surface plate] and the upper nozzle 3 (<J nozzle hole and nozzle receiving brick 4 expanded population 1jIi filled with By porosity, Tochi)/Electronic Table 2 In addition, this method 4 is applicable to the closing method of "Book 6". ■ Slip ink nozzle device &J, , shown in 7.
Sliding plate limited to J44 equipment or 1 piece complete set 111
etc.

Applicable to times, etc. -〇kiru.

As described above in detail, the present invention provides the nozzle hole 6-closed state V
In the nozzle hole of the controlled bed soil (ti), there is a granular light filling with a melting point exceeding the hot water temperature, and on the top of the warp, it melts at a temperature less than the hot water vorticity, and before melting, it has a foaming expansion jl length. A half-bath melting layer is formed on the surface of the low melting point granular filler during preheating depending on the filling process, or during storage in a bath. In addition, a foamed expansion heat insulating layer of a predetermined thickness is always generated under the membrane to prevent sintering of the high melting point granular filler in the nozzle hole during the waiting time for pouring out the stored bath water. It maintains good fluidity, and when the nozzle hole is opened, the filling material can be easily and instantaneously brought down together with the molten metal.Therefore, hazard 7+, oxygen lance operation noise is drastically reduced or eliminated, and the molten metal can be removed from the molten metal container. The molten metal can be poured into other containers or molds quickly, making the bath water treatment operation smooth and stable.For example, when continuous porcelain construction is carried out By using the ladle for pouring, it becomes viscous, and the surface and internal parts of the steel billet are excellent at commercial temperature during the rolling process. Therefore, the implementation rate of the continuous casting-rolling process will be reduced, and it will greatly contribute to energy saving and the production of high-quality steel materials, which are global issues in recent years.

[Brief explanation of drawings]

Fig. 1 is a side sectional explanatory view of the conventional method for preventing nozzle blockage; It is a 11 (II cross section M11) diagram showing a valley embodiment of the correct method. SN...Slighting nostle 3...
-1-, nozzle 5.9.9'...~'' 6.
10.10'...The first generation is used for contact point granular filling system New F1 Honura Rentai Shiki Company Zuf';IL'4 D Figure 2 1? n Figure 3 Ro 40 (10) Procedural Amendment (Method 〇 Showa) February 2, 1958 (, Indication of the case 1982 Special Plan Application No. 1593 '78 No. 2 Name of the invention Bath water pouring 7 nozzles Department's Obstruction Prevention Power Act 3, Relationship with the Ministry Case for Amendment Appointment of Patent Applicant J'I [Inu-FJJ'2-6-6-3
No. (665) and [Nippon Steel Corporation representative name] Takeshi Ibo 1) Yutaka 4゜Yoshihito “TlO2 24]-0444 19i
1-14i-12-5, Nihonbashi-honmachi, Chuo-ku, Tokyo, on the day of the Sodome Rei.] Monthly 25th, 1980 (first payment day), statement # (no change in content), detailed portrait J6 shell. , Pour the soil according to the attached sheet on page 1B.

Claims (4)

[Claims] (1) Before pouring the molten metal, in the bath water pouring nozzle part consisting of the upper nozzle brick and the sliding nozzle provided at the bottom of the molten metal container, the bath water It is characterized by filling a granular filler with a melting point that exceeds the temperature of the bath water, and filling the upper layer with a granular filler with a low melting point that melts in a foaming bath with a thickness below the bath water temperature. How to prevent it. (2) A method for preventing clogging of a molten metal pouring nozzle, characterized in that feldspar is used as a low melting point granular filler. (3) Particle size of low melting point granular filler ″f: 2.0 111
The first claim is characterized in that the number is less than or equal to m. Second. 11-bra method for preventing blockage of the molten metal pouring nozzle section described in (4) Claims 1 and 2 are characterized in that the low-melting point granular filler material is placed in a polyethylene bag in advance and introduced upward into the nozzle hole. 3. The method for preventing blockage of a molten metal pouring nozzle portion according to item 3.