Showing posts with label vertical continuous caster. Show all posts
Showing posts with label vertical continuous caster. Show all posts

Wednesday, July 7, 2021

Design of Continuous Casting Machine Foundation

The design of the continuous casting machine foundation is the basic structure design that supports and fixes the continuous casting machine and its related equipment, and transmits various loads and the dynamic loads of the equipment to the foundation through the foundation. The foundation of the continuous caster usually refers to the foundation of the ladle turret, intermediate tank, crystallizer, tension leveling device and shearing machine. Some of the columns of the continuous caster steel platform are also fixed on it. The main contents of the design include the collection of original data, basic form, basic calculation and basic structure.

The basic type of continuous casting machine has a variety of models such as vertical continuous caster, vertical bending, horizontal continuous caster, arc and multi-point bending. Continuous casting methods are divided into single-stream and multi-stream. Casting products include slabs, square billets, round billets and octagonal billets. The operation of casting billets is generally carried out by placing the ladle on a turntable or directly hoisting the ladle on a crane. Therefore, the basic forms are also different.
continuous caster

The structure of the foundation of the continuous caster is more complicated. From the ladle turret to the foundation of the shearing machine, the height is uneven. According to the design of some projects, the top level of the foundation is as high as 10~15m, and the height of the base is 5~-8m. Trenches and cable tunnels are arranged in the foundation (see picture). The load of each part of the foundation is quite different. Therefore, it should be based on the foundation design plan (such as natural foundation or pile foundation, etc.), the layout of process equipment, the distribution of the load of each part, the layout of the channel in the foundation, and the relevant design specifications. The specified allowable maximum length of the foundation and other conditions, reasonably determine the location of the foundation deformation joints. The foundation of the continuous caster is a mixture of block type, wall type, frame type, box type, pit type, beam, plate type and other structural forms.

The loads and external forces acting on the foundation include:

(1) The weight of the equipment acting on the foundation and the structural dead weight from the steel platform of the continuous caster and the weight of the equipment acting on the steel platform, and the single molten steel when the continuous casting machine is running. The deadweight, molten steel weight and operating load of the ladle and double ladle.

(2) Horizontal force, bending moment and torque generated during equipment operation.

(3) The external force generated by abnormal operation during the production process, for example, the vibration caused by the unstable operation when the ladle is placed on the turntable. In this case, the weight of the molten steel and the ladle is generally multiplied by the power coefficient. Since the ladle can change positions on the turntable, the unfavorable load combination generated when the ladle is at different positions must be considered.


The calculation points of the foundation are as follows:

(1) When the various parts of the foundation of the continuous caster are decomposed into wall, frame, box, pit or beam-slab components, the internal force and reinforcement must be carried out according to their actual stress conditions. (2) When the cable tunnel and the water trench are located at the edge of the foundation, where the trench wall is thin, and the groundwater level is higher than the bottom elevation in the trench, the influence of groundwater pressure on the bearing capacity of the trench must be considered and the crack width must be checked.

(3) The center of gravity of the applied load, the weight of the overburden and the weight of the foundation and the centroid of the bottom of the foundation should be located on the same vertical line as far as possible. Check the bearing capacity of the foundation based on the above loads.

(4) When the foundation of the continuous casting machine is built in the seismic fortified area, the seismic check calculation must be carried out. When the foundation is built on a soft soil site, pile foundations or other artificial foundations can be used.

continuous casting machine

The basic structure of the continuous caster is mainly as follows:

(1) The ladle turret and its supporting frame or wall underneath are generally subjected to high strength, so the concrete with strength grade C25 or C30 is generally adopted the continuous caster foundation adopt C20 or C25. Concrete.

(2) The foundation is made of ordinary reinforced concrete. On the top of the ladle turret, it is necessary to locally build refractory bricks vertically and horizontally to insulate the foundation body according to the requirements of the process. When the refractory bricks are erected vertically, they need to be tied with the embedded steel bars of the foundation.

(3) The anchor bolts of the equipment are mostly deadbolts buried at one time. In the range of the ladle turret platform, T-head live bolts are generally used. For large continuous casting machine, prestressed bolts should be used. Since bolts are mostly made of high-strength steel, electric welding and fire are strictly prohibited during construction and installation.

(4) Reasonably choose the location of construction joints, and it is not advisable to set up more construction joints to facilitate the integrity of the foundation. During construction, it is necessary to take appropriate measures according to the construction season to avoid shrinkage cracks during concrete pouring.

(5) Settlement observation points should be embedded in the four corners of the foundation exposed to the ground.

Looking for the continuous caster or relevant spare parts, please mail at marketing2@hanrm.com.

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Tuesday, June 16, 2020

What Are the Main Types of Continuous Caster?

continuous caster

Vertical continuous caster

The vertical continuous caster is the main model before the 1950s-1960s. The steel pouring system, mold, cutting device and billet outlet position of the caster are all arranged on the vertical axis of the caster, and the whole equipment occupies a large space in the workshop.

During the production of the vertical continuous caster, the slab solidifies in the mold and secondary cooling section. Because of the vertical arrangement, the non-metallic inclusions in the liquid metal are easy to float up, the heat dissipation around the slab is relatively uniform, and the slab is not affected by other bending forces during the drawing process. The quality of the slab is good and it is not easy to crack, so it is more suitable for the production of alloy steel and other crack sensitive products steel grade of the sensor. However, the height of the caster is too high, the investment of infrastructure and equipment is large, and the maintenance is also difficult. Because of the high head casting, the lower section of the slab is prone to bulging deformation under the hydrostatic pressure of the molten steel, so it is only suitable for the production of small section slab.

Vertical bending caster
The vertical bending caster is a transitional type of caster developed on the basis of the vertical caster. The difference between the upper part and the vertical continuous caster is that the vertical bending continuous caster uses the top bending device to bend the slab 90°after it is completely solidified, so that the slab can be drawn out and cut in the horizontal direction. The vertical bending caster reduces the height of the whole machine in part, but because it is bent up after the slab is completely solidified, it is easy to crack and other defects in production, which is mainly used in the production of small section billet.

Arc caster

Arc caster is the most widely used type in the world. Its mold, secondary cooling section and billet straightener are all arranged on 1 / 4 circumference of the same radius. The billet is completely solidified in 1 / 4 circumference. After a point of straightening at the horizontal tangent line, it must be pulled out in the horizontal direction, and then cut to a certain length.

1. Full arc caster

Full arc continuous casting machine is also called single-point straightening arc anchor machine. The secondary cooling device of the mold and the tension straightening device of the full arc caster is all arranged on around 1 / 4 arc. The billets form an arc in the mold, move along the arc track after pulling out, and receive water spray cooling until complete solidification. After full solidification, the billet is straightened to the horizontal cutting point, and then the continuous casting machine is pulled out to cut into a fixed length, which is output from the horizontal direction. The height of the continuous caster is basically equal to the arc radius. Generally, the external arc radius of the continuous casting machine is called the arc radius of the arc continuous casting machine.

The main features of full arc caster are summarized as follows:

Main advantages:

(1) Because it is arranged in the range of 1 / 4 arc, its height is lower than the vertical and vertical bending type, the equipment quality is lighter, the investment cost is lower, the equipment installation and maintenance are convenient, so it is widely used;

(2) Because of the low height of the equipment, the static pressure on the billet during solidification is relatively small, which can reduce the internal crack and segregation caused by bulging deformation, and improve the casting speed and quality.

Main disadvantages:

(1) During the solidification process of molten steel, the non-metallic inclusions tend to accumulate in the inner arc, which is easy to form the defect of inclusions enrichment at about 1 / 4 of the side of the inner arc;

(2) In order to prevent internal crack, it is required that the slab should be completely solidified before straightening, which limits the improvement of drawing speed and affects the production capacity.

continuous casting machine

2. Multiple points straightening arc caster

The schematic diagram of multiple points straightening arc caster is shown in the figure below. With the increase of casting speed, the slab can't be completely solidified when it reaches the straightening point. When the slab with the liquid core is straightened at a single point, due to a large amount of solid-liquid interface deformation, the central area of the slab is prone to crack. Therefore, the multiple point straightening technology is used to disperse the total strain into the strain of each straightening point, so as to reduce the solid-liquid interface deformation rate. In this way, the billet can be straightened with a liquid core without internal cracks, which is conducive to improving the drawing speed.

3. Arc continuous caster with direct mold

The straight mold arc caster (straight arc Caster) adopts the straight mold, which is equipped with a straight section of 2.5-3.5m below the mold. After the straight section, the slab with the liquid core is gradually bent into an arc, and the subsequent process is exactly the same as that of the multiple point straightening arc caster.

Main advantages:

(1) The advantages of the vertical continuous caster are retained. During the solidification process of molten steel in the straight mold and its lower straight section, it is beneficial to the floatation and uniform distribution of large inclusions in the molten steel. The defect of inclusion enrichment at 1 / 4 of the inner arc side of the slab is avoided, and the effect of high-purity steel production is obvious;

(2) Because the billet is curved into an arc with liquid core, it still has the advantages of low equipment height and low construction cost.

Main disadvantages: the straight arc caster has one more bending process, which increases the possibility of cracks on the outer arc side for crack sensitive steel.

It should be said that the straight mold arc caster is a new type of caster integrating the advantages of vertical and arc caster. At present, more and more slab casters in steel plants adopt this type of caster, because it can better meet the requirements of slab quality and improve production efficiency.

More Articles You May Be Interested:

1. Technological Features of Continuous Billet Caster

2. Continuous Casting Machine

3. What is Continuous Casting and Continuous Rolling?

4. Continuous Rolling, Semi-continuous and Slit Rolling Processes of Rolling Mills

5. What is the difference between horizontal continuous casting and arc continuous casting?

6. How Does Horizontal Continuous Caster Realize Billet Drawing?

7. Why Develop Horizontal Continuous Casting Technology?

8. What’s the Main Equipment of the Horizontal Continuous Casting Mill?

9. Continuous Casting Machine Equipment

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