JPS6041337Y2 - Pour construction frame for monolithic refractories - Google Patents

Description

[Detailed description of the invention] This invention is used in the steel industry to store high-temperature molten metals such as molten steel in order to move or react them, especially circular or nearly circular containers such as ladles, hot metal ladle, vacuum degassing This invention relates to improvements in construction frames used when pouring monolithic refractories into the side walls of high-temperature processing furnaces such as containers.

In recent years, the construction of refractory linings for high-temperature treatment furnaces has increasingly been carried out using a casting method using monolithic refractories.

For example, when constructing the side wall work lining of a ladle, as shown in the longitudinal cross-sectional view in Fig. 1 and the second factorial view, the work should be done approximately at the center of the ladle 1, with a gap corresponding to the construction thickness of the side wall work lining 2. A method is used in which a cylindrical construction frame 3 is installed at the position where the side wall work lining 2 is formed by pouring a monolithic refractory for pouring into the gap from the upper part of the waist.

Problems in construction using such a conventional construction frame will be described, for example, regarding a ladle.

l The state of erosion of the side wall due to the use of the ladle is not uniform;
For example, the side wall work lining 2, which is constructed using the construction frame 3 as shown in Fig. 1, is completely damaged due to deformation damage, where the sludge side is rapidly eroded and the anti-slag side is less eroded. Since the circumferential surface has the same thickness, the life of the ladle lining is short, forcing it to be discontinued due to the progression of erosion on the slag side.

To prevent this, as shown in Figures 3 and 4, the construction frame 3 is shifted in an eccentric position so that the wall thickness on the slag drainage side is 2.
′ and thinner the wall thickness 2″ on the anti-slag drainage side, but this only requires extremely complicated work for positioning by moving the heavy construction frame a predetermined distance to one side. Rather, if the side wall on one side is made thicker, the wall thickness on the other side will inevitably become thinner, which is not a fundamental solution and cannot be used for a long time.

2 Molten steel and molten slag seep into the contact area between the bottom of the side wall work lining 2 and the outer periphery of the side work lining 4 in Fig. 1, the so-called corner part 5, and with repeated use, the corner part becomes large and hollow. This will lead to melting and damage, causing premature repair.

As a preventive measure against this, a method has been taken in which several steps of side wall protection brickwork 6 are constructed over the entire circumference of the lower inner side of the side wall work lining 2 to protect a portion of the entire circumference of the corner, as shown in Fig. 5. When the ladle is used several times, a gap is formed in the contact wall surface between the side wall lining 2 and the protective brickwork 6, and molten steel and molten slag permeate there, causing a part of the brickwork to be pushed inward.

When one part of the brickwork falls off, the joints open in the circumferential direction, which causes the brickwork to lose tension and easily fall off as a whole.

Even so, as the refractory lining was used repeatedly, the contact surface between the side wall 2 and the lining 4 expanded, and it functioned as temporary protection until the contact surface between the side wall 2 and the lining 4 became familiar and firmly bonded. When the harsh conditions of use such as stirring increase, the flow of molten steel especially at the corner portion 5 is intense, so that it is difficult to prevent abnormal melting damage at the corner portion with the protective brickwork 6 described above.

3 Next, when the pouring construction is completed, wait for the constructed lining structure to harden and then remove the construction frame (remove the frame).

At that time, a bond strength that does not collapse even if the frame is removed is required, but cast monolithic refractories require binding materials such as alumina cement or finely powdered fireclay, or chemical hardening agents such as calcium hydroxide. Therefore, it takes 10-30B to reach the required hardness at room temperature.

In order to shorten this time, measures were taken to increase the amount of binding material and hardening material, but this resulted in a decrease in the durability of the refractory lining.

Particularly in the winter, the hardening effect is slow, which in the case of ladles causes problems in so-called ladle rolling, which has a negative impact on the entire steelmaking process.

In addition, heating the refractory lining to around 50°C will accelerate its hardening, so raising the temperature inside the construction stone form to 200-300°C was considered, but this would not only result in larger equipment, but would also require a wider wall surface. It is difficult to heat evenly, so it has not been put to practical use.

In particular, chemical curing agents that have recently been used are particularly problematic because their curing reactions are greatly affected by the environmental temperature.

4 Another problem with conventional construction frames is that in order to increase the degree of filling of the poured monolithic refractory and form a homogeneous refractory lining, a vibrator is inserted into the poured material as shown in Figure 1. 7 had to be buried to give vibration to the poured material.

However, as the falling surface of the poured material rises, the vibrator 7 must be moved upward one by one, and two to four vibrators are installed depending on the size of the ladle and the thickness of the construction, so it is necessary to control them. The amount of work involved was enormous.

Although the problems in the ladle in casting monolithic refractories using a conventional construction frame have been explained above, similar problems also occur in other molten metal containers.

The construction frame of this invention solves the problems of the conventional construction frames, enables the construction of side walls in response to erosion and damage conditions, uniform heating of the refractory lining to a suitable temperature, and also provides vibration without the need for manual labor. The purpose of the construction frame is to provide a construction frame in which the top plane of the construction frame has a circular shape with a part cut out, and the bottom plane has a stepped part and is reduced to a similar shape to the top plane. This is a pouring construction frame for monolithic refractories, which has a small shape, has an outer wall as a passage for hot air, and is further provided with a vibrator in contact with the inner side of the outer wall.

This invention will be explained based on the drawings. FIG. 6 is a longitudinal sectional side view of a ladle in which a construction frame of this invention is set, and FIG. 7 is a plan view thereof.

In Figures 6 and 7, 8 is the outer shell of the ladle, 9 is the side wall permanent lining, 10 is the side wall work lining, 1
1 is the bottom work lining.

Kogyo is a construction frame of this invention which is set on a work lining 11 and has a notch 13.
2 and the side wall permanent lining 9 is poured and filled with monolithic refractory material to form the side wall work lining 10.

At this time, if the notch part 13 of the construction frame (■) is set to match the part of the side wall work lining that is subject to severe erosion, such as the side wall work lining 14 on the waste slag side, and pouring is carried out,
As shown in FIGS. 6 and 7, the side wall work lining 14 on the waste side is thicker, and the side wall work lining 15 on the side opposite to the waste waste is not thinner as before.

Next, the construction frame 1 of this invention has a stepped portion 16 at the bottom and has a reduced bottom portion.

That is, the top plane and bottom plane of the construction frame 12 have similar shapes, but are bent inward by the stepped portion 16 and have a contracted shape.

Note that in the case of a ladle, the planar shape of the step 16 is smaller than the top plane because the side wall work lining 10.14.15 is inclined inward, but in the case of a container with an upright side wall, the planar shape of the step 16 is smaller than the top plane. The planes have the same shape.

When pouring is carried out using the construction frame (2) having the stepped portion 16 as described above, the corner portion 17 of the ladle, where the melting damage is most severe, will be thickly poured over the entire circumference.

The features of the shape of the formwork 12 of this invention have been described above, and the second feature is that the outer wall is used as a hot air passage.

That is, the outer wall of the formwork industry has a double wall structure made of steel, consisting of an outer peripheral wall 18 and an inner peripheral wall 19, which are fixed to each other by peripheral wall supports 20.

The double wall communicates with the hot air pipe 21 to form a hot air passage 22.

Therefore, when hot air or steam at 70°C to 400°C is blown from the hot air inlet 23 at the top via a known blower or the like, it passes through the hot air pipe 21 and the hot air passage 22, and enters the atmosphere from the hot air opening 24. released.

During this time, the completed side wall work lining 10 is heated evenly to about 30°C to 80°C over the entire circumference via the outer peripheral wall 18, so that the poured material can harden in a short time and can be removed from the frame. .

Since this idea has the structure as explained above, the inner thigh of the side wall lining of the ladle can also be thickened at the same time on the slag side and a part of the bottom corner of the side wall, which are prone to erosion, in one regular pouring operation. This eliminates troublesome work such as eccentric positioning of formwork and protective brickwork of side walls, and
It is possible to construct a lining with a well-balanced thickness for erosion and damage, and the service life of the ladle lining can be extended.

In addition, since the average heating and curing of all construction objects can be carried out directly under the pouring process, the curing time can be shortened to 1/3 to 1/4 of the conventional time.
Even in the harshest of winters, it cures quickly and can be removed from the frame in a short time.

Therefore, the entire pot factory can operate stably.

Furthermore, the time required to dry and heat up the refractory lining, which is the next step after curing, was also reduced by about 10%.

Next, the third feature of this invention is that a vibrator 25 is provided inside the outer wall of the formwork, that is, in contact with the inner circumferential wall 19.

As mentioned above, in order to increase the filling degree and homogenize the poured refractory material, conventionally a pie break is embedded in the material to give vibration, but this not only requires a large amount of work but also takes a lot of space. It was not possible to fully achieve the objectives of the period.

In this invention, as shown in FIGS. 6 and 7, the vibrators 25 are attached at appropriate intervals so as to be in close contact with the inner circumferential wall 19 of the construction frame (2).

FIG. 6 and FIG. 7 show an embodiment in which eight sets of upper and lower Nieras motor type vibrators are installed.

When the pie break-25 is activated, the outer peripheral wall 1 of the construction frame 12
Since strong vibrations are applied to the entire pouring material through the pump 8, filling and homogenization of the pouring material can be achieved without the need for manual labor, and a good refractory lining can be obtained.

The type and number of vibrators to be installed must be selected depending on the structure and size of the construction frame, and the type of pouring material.
Vibration frequency 3000-12000V.

It is preferable to install one set of P and M0 amplitudes of 0.01 to 0.87 rrIn per wall surface of 5 to 71 inches.

Note that the planar shape of the construction frame with a part of the circle cut out may be an elliptical shape as shown in A in the factor 8 cross-sectional view, or By using various planar shapes such as the polygon shown in B and the compound circular shape shown in C, it is possible to construct side wall linings with various wall thicknesses that are not equal in thickness depending on the state of melting damage.

Further, since the abnormal melting loss of the lower corner portion 17 varies depending on the ladle and the type of container, the degree of bending of the stepped portion 16 may be arbitrarily designed depending on the actual situation.

As explained above, the construction frame of this invention has a simple structure, and the lining construction of any shape and wall thickness can be performed in one pouring process to cover unbalanced erosion and abnormal erosion of ladles and other molten metal vessels. It can be constructed with

In addition, curing of the refractory lining can be completed uniformly and in a short time by simply blowing hot air, extending the service life of the lining of containers such as ladles, shortening the construction period, and increasing the curing period. It is highly effective in reducing width and saving labor in construction.

This idea can be applied not only to ladles, but also to all types of work such as partial repair, intermediate repair, full-scale repair, and construction of new linings on the side walls of circular or circular-like molten metal containers.

[Brief explanation of the drawing]

Figures 1 to 5 show the prior art. Figure 1 is a vertical cross-sectional view of the construction frame in normal use, Figure 2 is a plan view of Figure 1, and Figure 3 is the eccentric use of the construction frame. 4 is a plan view of FIG. 3, and FIG. 5 is a longitudinal sectional view showing the side wall protection brickwork. Figures 6 to 8 show examples of this invention.
The figure is a longitudinal side view, FIG. 7 is a plan view of FIG. 6, and FIGS. 8A to 8C are plan views showing construction frames of other embodiments. In Figures 6 to 8, 10...Side wall work lining, 12...Construction frame, 13...
- Notch part of the construction frame, 16... Stepped part at the bottom of the construction frame, 17... Part of the corner of the ladle, 18...
... Outer peripheral wall of the construction frame, 19 ... Inner peripheral wall of the construction frame, 20 ... Curved peripheral wall support, 21 ... Hot air pipe, 2
2...Hot air passage, 23, song/hot air inlet, 24
...Hot air opening, 25...Pibrator

Claims (1)

[Scope of utility model registration request] The top plane has a circular shape with a part cut out, and the bottom plane has a stepped part and is reduced to a similar shape to the top plane,
A pouring construction frame for monolithic refractories, which has an outer wall with a hot air passage and a vibrator in contact with the inner side of the outer wall.