Arc Continuous Caster

The arc continuous caster is also called the full arc continuous caster. The mold of the arc continuous caster is arc-shaped, and the secondary cooling device is in a quarter of the arc to form an arc-shaped casting billet in the mold. During the downward movement of the arc-shaped roller table, it is cooled by spraying water until it is completely solidified. After being fully solidified, the cast billet enters the straightening machine at the horizontal tangent point and then is cut to length.

The arc continuous caster is composed of ladle turret, tundish and conveying device, crystallizer and vibrating device, secondary cooling device, multi roller tension leveler, dummy bar and its storage platform, dummy bar removal device, cutting and collecting device, billet cutting equipment, etc.

1. Steel Drum Rotating Table

The ladle filled with molten steel transported from the steelmaking furnace is hoisted on the support frame by a crane, and then the support frame is rotated 180° above the intermediate tank to inject the molten steel into the intermediate tank. After pouring, rotate 180° to the receiving position, and hoist the empty can. When multiple furnaces are continuously poured, two steel buckets can be placed on the supporting frame at the same time. After one bucket of molten steel is poured into the intermediate tank, the supporting frame rotates 180°, and the other bucket of molten steel reaches the top of the intermediate tank.

2. Tundish

Tundish is an intermediate vessel between steel barrel and mould. The molten steel is injected into the mould from the tundish. The tundish is composed of tank body, tank cover and nozzle stopper.

3. Crystallizer

There are two types of crystallizers: curved and straight, which can be divided into three types: integral type, sleeve type and combined type. The width and thickness of the inner cavity of the combined mold can be adjusted. The crystallizer is composed of inner wall, outer shell, cooling water circuit and supporting arm. The material of the mold is mainly copper and copper-based alloys (phosphorus deoxidized copper, silver-containing copper, etc.). In order to increase the abrasion resistance of the inner wall, a thin layer of chromium or nickel is often plated. The length of the crystallizer is usually 700-900mm, the crystallizer taper is generally 0.5% to 0.9%, and the round billet crystallizer taper is 1% to 1.2%.

The vibration device of the mold generally adopts small amplitude and high-frequency vibration parameters, the amplitude is not more than 4mm, and the frequency is more than 150 times/min. The purpose of the vibrating device is to obtain a good lubrication condition for the inner wall, reduce friction, and prevent the molten steel from adhering to the inner wall.

4. Secondary Cooling Support Guide

The function of the secondary cooling supporting and guiding device is: direct water spraying can be used to cool the casting billet, supporting and guiding the casting billet and the starter chain, and preventing the deformation of the cast billet and the deviation of the starter chain. The secondary cooling guide section of the billet continuous caster is relatively simple. The slab caster adopts a close-packed roll structure with small diameter and small roll spacing. The guide section and the tension leveler are made into several fan-shaped sections, which is convenient for maintenance, replacement and arc alignment.

5. Straightening Machine

The drawing straightening machine is called a straightening machine for short. It is used to pull the dummy bar chain and the slab condensed with it out of the mould continuously and straighten the slab. It is liquid core tension straightening to use multi roll tension straightener to make the casting billet which is not completely solidified enter the tension straightener, which can improve the drawing speed and productivity.

The stretch-straightening machine of the billet continuous caster generally adopts a 5-roller pneumatic or hydraulic pressing type, the slab continuous caster adopts a multi-roll stretch-straightening machine, and the bloom and round billet adopt a single-frame stretch-straightening machine that can be replaced as a whole.

The starter chain is the "live bottom" of the crystallizer. The lower mouth of the crystallizer is blocked, and some scrap steel plates are placed on the starter head, so that the casting billet and the starter head are firmly connected, and the tail of the starter chain is clamped in the tension leveler. In the machine. After the start of casting, the starter chain head gradually condenses with the billet. After starting to draw the billet, the tension leveler forcibly pulls the starter chain and the steel billet connected to it from the mold until the billet is straightened and the starter chain is taken off, and then it leaves the continuous casting production line for storage.

6. Cutting equipment

A Shearing machine or flame cutting machine can be used to cut the casting billet. For billets with a cross-section of no more than 200mm×200mm, shears are generally used, and flame cutting machines can also be used for long-length billets. For square billets, round billets and slabs with a cross-section greater than 200mm×200mm, flame-cutting machines are generally used. There are electric and hydraulic shearing machines, and the shearing machine with a shearing force greater than 5000kN generally adopts the hydraulic type. The fire-burning cutting equipment consists of a cutting mechanism, a synchronization mechanism, a return mechanism, an end face detector, a fixed-length mechanism, and an oxyacetylene pipeline system. 

Advantage

The arc continuous caster is arranged in the quarter arc range, so its height is lower than that of the vertical bending continuous casting machine. This feature makes its equipment lighter, lower investment, and equipment installation and maintenance. Convenience.

Due to the low height of the equipment, the cast slab bears relatively small hydrostatic pressure during the solidification process, which can reduce internal cracks and segregation caused by the deformation of the bulge, which is beneficial to increase the drawing speed and improve the quality of the cast slab.

Industrial Technology Level

Commonly referred to as continuous casting technology is a variety of technologies targeted at arc continuous casting machines. The industrial technology level reached by the arc continuous casting machine can be summarized as follows:

1) Casting machine production capacity: The single production capacity of modern large-scale slab casters is generally 2 to 2.5 million t/a. The American Harper (LIV/Indiana Harbor) plant set an annual output of 3.05 million t/a in 1987. . The single production capacity of the bloom caster can reach 800,000 to 1 million t/a. The single production capacity of the billet multi-strand continuous caster can reach 600,000 to 800,000 tons.

2) Casting machine operating rate: generally above 80%, and more advanced casting machines can reach 85-90%.

3) High-speed casting: The general drawing speed of the slab continuous casting machine is 1.2～1.8m/min. The newly built No. 5 machine of the Fukuyama Plant of Japan Steel Pipe has created the highest record of 3.0m/min.

4) Multi-furnace continuous casting: Generally, the number of continuous casting furnaces is 4-6 furnaces on average, and there are also more than 10 furnaces. The twin-strand slab caster of the Porttalbot Plant of the British Steel Union (BSC) set a record of 300 continuous casting furnaces (with a molten steel volume of 102,000 tons) in 1987. The single-strand slab caster of American Steel's Gary Plant set a record of 329 continuous casting furnaces. In January 1988, the monthly output reached 318,500 tons.

5) The range of slab cross-section dimensions actually produced by the casting machine, mm:

Slab 125×650～220×2720 (strip steel, welded pipe billet), 350×1300

150×1000～320×1600 (thick plate), 310×2500

Bloom 200×200～600×670 (rod, shape, wire)

φ230～φ450, 560 octagonal (tube) shaped blank, 480×420×720 (rail beam)

Billet 80×80～145×145 (wire)

100×100～240×240 (rods, shapes, materials)

φ115～φ210 (pipe, rod, material)

6) Extensive use of computer technology: The production process and production management of modern continuous casting machines are automatically completed by computers.

Installer

The arc continuous caster has established a complete and accurate measurement control network before installation. The installation procedure can be determined according to the conditions of the construction site, the sequence of equipment arrival, and the requirements of the construction period.

The more reasonable installation procedure is to take the tension leveler as the positioning equipment and use its tangent point roll for positioning. Firstly, install the tension leveler curve section, align the tangent roll axis of the curve section with the transverse datum line, and the top elevation of the tangent roll is ± 0 (top elevation of discharge roller). After positioning the curve section of the tension leveler, it can be divided into two main operation lines for installation at the same time. One operation line is carried out from bottom to top in the reverse direction of casting flow, and the sequence is: lower frame of secondary cooling device → upper frame → upper beam → segment replacement device → segment → mould vibration bench and transmission device → transition segment → mould. The first line is the straight section of the tension leveler, and then the output roller table, dummy bar stand, dummy bar removal equipment and cutting equipment.

The secondary cooling device is the main part of the continuous casting machine. The complete set of equipment is located in the cooling room. After the fan-shaped section is installed, a large number of pipeline projects in the cooling room will be constructed immediately. According to the drawings, choose a reasonable construction procedure: equipment cooling water pipes, spray water pipes, Sector hydraulic pipes, dry oil lubrication pipes.

After the installation of the curved section and the straight section of the straightening machine, piping construction should be carried out. The sequence is compressed air pipe→hydraulic pipe→spray cooling water pipe→equipment cooling water pipe.

The hydraulic station matched with the continuous caster and the water distribution chamber of the secondary cooling device are complicated in the system and large in engineering volume, which must be carried out at the same time as the continuous caster.

The ladle rotating platform and tundish car traveling device on the casting platform should also be constructed in parallel with the continuous caster.

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

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