CN101444837A - Method for forming turbulence by cooling water in continuous casting crystallizer and crystallizer - Google Patents

Abstract

The invention discloses a method for forming turbulent flow by cooling water in a continuous casting crystallizer and a turbulent flow continuous casting crystallizer, a continuous casting crystallizer composed of a water jacket, a cooling water slot, and a copper crystallizer, and the water jacket and the copper crystallizer (including a round mold) Billet, square billet, slab or rectangular billet), the cooling water gap is characterized in that there are protrusions or grooves on the surface of the outer wall of the copper crystallizer, so that an uneven gap is formed between the water jacket and the outer surface of the crystallizer. Water seam, when the cooling water enters the cooling water seam, the cooling water encounters the protrusions or grooves provided on the outer wall surface of the copper crystallizer, which changes the flow direction of a part of the cooling water, so that the cooling water flows in a turbulent form. By enhancing the turbulent effect of the water flow, the cooling water can fully participate in heat exchange in the water gap, improve the cooling effect and service life, and increase the casting speed of the continuous casting slab. It can be widely used in the continuous casting of steel, copper and aluminum. Continuous casting of various non-ferrous metals.

Description

Method for forming turbulent flow of cooling water in continuous casting crystallizer and crystallizer

technical field

The invention belongs to metal continuous casting technology, and in particular relates to a method for forming turbulent flow of cooling water in a continuous casting crystallizer and a turbulent continuous casting crystallizer.

Background technique

Metallurgical continuous casting technology has experienced "experimental development in the 1940s, industrial production in the 1950s, the emergence of arc-shaped continuous casting machines in the 1960s, great development in the 1970s, increasingly mature technology in the 1980s and a crisis in the 1990s. New reforms" nearly 60 years of historical development. High-efficiency continuous casting is a continuous casting technology developed in the middle and late 1980s. It refers to higher production efficiency than conventional continuous casting. With high casting speed as the core and high-quality, high-temperature and defect-free billet production as the basis, high-efficiency continuous casting, High-efficiency continuous casting system technology is an important development direction for optimizing contemporary continuous casting production. High-efficiency continuous casting technology is highly valued by major iron and steel companies, engineering companies, and equipment manufacturers in the world, because it has further played a role in reducing investment costs, improving production efficiency, simplifying technological processes, and reducing consumption and costs. Taking advantage of the advantages of continuous casting technology, significant progress has been made in increasing casting speed in recent years.

The continuous casting crystallizer is the billet forming equipment in the continuous casting steel, and it is one of the core equipment of the continuous casting machine. Its basic function is to use the cooling water to indirectly take away the heat from the molten steel through the water-cooled copper plate, so that the molten steel can continuously form a billet shell with a certain thickness and a certain strength in the crystallizer. During this process, the crystallizer has been under the combined effects of mechanical stress and thermal stress, and the working conditions are relatively harsh. In addition to standardizing production operations, selecting appropriate mold powders, and avoiding mechanical damage, rationally designing the cooling water joints of the mold can effectively improve heat transfer efficiency, improve continuous casting productivity, maintain normal production during continuous casting, and ensure casting Billet quality plays a vital role. Therefore, it is particularly important to research and develop new crystallizers in today's metallurgical production.

Research on the crystallizer of high-efficiency billet continuous casting machine abroad Since the continuous casting machine entered the field of industrial production, many foreign iron and steel scientists have begun to conduct extensive and in-depth research on the key component of the continuous casting machine crystallizer, including Demark The company's parabolic taper crystallizer, STEL-TEK's spray crystallizer, Comcast's CCT crystallizer, Danieli's DANAM crystallizer and VAI's DIAMOND crystallizer, etc. Domestic iron and steel researchers have also done a lot of work on the research on the heat transfer mechanism of slabs. Colleges and universities such as Northeastern University, Beijing University of Science and Technology, and scientific research institutes such as Beijing Iron and Steel Research Institute have many studies on the heat transfer mechanism of slabs and molds. Research design articles on thermal mechanisms have been published in recent years. Related research from the perspective of the mold, mainly focused on the research of mold back taper, mold wall thickness, mold copper tube material, mold water gap width, water velocity and water temperature, negative sliding time and mold lead .

At present, the outer wall structure of the crystallizer always uses a flat and smooth plane or a curved surface (the square crystallizer is a plane, while the circular crystallizer is a curved surface), and the cooling water flow in the water slot of the crystallizer is a laminar flow state, and is formed in layers Flow state for water heat exchange and cooling crystallizer. Therefore, since the cooling water is in a laminar flow state, the flow of water is relatively stable, there is no relative flow, or agitation, so the speed of heat exchange between the water and the wall of the crystallizer is relatively slow, that is, the heat exchange rate is low. , the cooling effect is relatively slow, which ultimately affects the casting speed and also affects the production efficiency of the enterprise.

Contents of the invention

The purpose of this invention is to improve on the basis of the existing crystallizer technology, and to overcome the shortcomings of the existing crystallizer technology, to propose a method that can increase the heat exchange area between the crystallizer and cooling water, and improve the flow state of water in the water gap A method for making the cooling water in the water gap form a strong turbulent flow, and a turbulent continuous casting crystallizer which improves the cooling effect and service life, and can increase the casting speed of the continuous casting slab.

The technical scheme adopted in the present invention is:

A method for forming turbulent flow of cooling water in a continuous casting crystallizer, adopting a continuous casting crystallizer composed of a water jacket, a cooling water slot, and a copper crystallizer, the water jacket and the copper crystallizer (including round billet, square billet, slab or rectangular The cooling water gap is formed between the blanks, and it is characterized in that: there are protrusions or grooves on the surface of the outer wall of the copper crystallizer, so that uneven water gaps are formed between the water jacket and the outer surface of the crystallizer, and when the cooling water enters the cooling When the water cracks, the cooling water encounters the protrusions or grooves provided on the outer wall surface of the copper crystallizer, which changes the flow direction of a part of the cooling water, so that the cooling water flows in a turbulent form.

A turbulent continuous casting crystallizer, comprising a water jacket (1), a copper crystallizer (3), and a cooling water gap (2) formed between the water jacket (1) and the copper crystallizer (3), characterized in that: The surface of the outer wall of the copper crystallizer is provided with protrusions or grooves, so that uneven water gaps are formed between the water jacket and the outer surface of the crystallizer.

The surface of the outer wall of the copper crystallizer is provided with intermittently arranged transverse trapezoidal convex lines or grooves.

The surface of the outer wall of the copper crystallizer is arranged with horizontal and vertical rectangular grooves, and lump-shaped protrusions are formed on the surface of the outer wall of the copper crystallizer.

The beneficial effects and advantages that the present invention has are:

(1) Increase the heat dissipation area on the outer surface of the crystallizer, that is, increase the heat exchange capacity between the crystallizer and cooling water, and improve the cooling effect;

(2) Change the flow state of the cooling water to form a turbulent flow, effectively increase the heat exchange capacity between the crystallizer and the cooling water by using the turbulence effect, and the comprehensive heat transfer coefficient is above 4000W/m ² to improve the cooling effect;

(3) The structure of the turbulent-flow high-efficiency cooling continuous casting mold is reasonable, and it can ensure that the temperature of the copper plate of the mold is low enough to avoid boiling of the cooling water, and at the same time, it does not exceed the phase transition temperature of copper of 250°C, thereby improving the service life of the mold;

(4) Due to the turbulent flow of the cooling water in the water slot, the formation of scale on the surface of the crystallizer by the cooling water can be avoided to a certain extent.

The invention can increase the casting speed of the continuous casting slab, and can be widely used in the continuous casting of steel and various nonferrous metals such as copper and aluminum.

Description of drawings

Fig. 1 is a structural schematic diagram of the annular groove turbulent flow continuous casting crystallizer used for round billets according to the present invention.

Fig. 2 is a schematic structural view of the annular groove turbulent flow continuous casting crystallizer used for billets according to the present invention.

Fig. 3 and Fig. 4 are longitudinal sections and partial enlarged views of the turbulent cooling continuous casting crystallizer of the present invention.

Fig. 5 is a schematic structural view of the block-shaped raised turbulent flow continuous casting crystallizer used for round billets according to the present invention.

Fig. 6 is a schematic structural view of the turbulent-flow continuous casting crystallizer with block-shaped protrusions for billets according to the present invention.

Fig. 7 is a schematic diagram of laminar flow in the water gap between the ordinary crystallizer and the water jacket.

Fig. 8 is a schematic diagram of the turbulent water flow in the water gap between the cooling crystallizer and the water jacket of the annular groove (or raised bar) of the present invention.

Specific implementation method

The present invention will be further described below with reference to the drawings and examples (the present invention is not limited by the structural form of the turbulent continuous casting crystallizer described in the examples).

The invention discloses a method for forming turbulent flow of cooling water in a continuous casting crystallizer. The continuous casting crystallizer composed of a water jacket, a cooling water seam and a copper crystallizer is adopted. The cooling water seam between the water jacket and the copper crystallizer is formed in the copper crystal There are protrusions or grooves on the surface of the outer wall of the crystallizer, so that an uneven water gap is formed between the water jacket and the outer surface of the crystallizer. After opening or grooves, the flow direction of a part of the cooling water is changed, so that the cooling water flows in the form of turbulent flow in the cooling water gap. The turbulence effect of the enhanced water flow is used to make the cooling water participate in heat exchange in the water gaps.

Example 1: Annular groove (or convex strip) turbulent flow high-efficiency cooling continuous casting mold

As shown in Figure 1, the annular groove (or convex strip) turbulent high-efficiency cooling continuous casting mold is used in the structure of the round billet continuous casting mold. As shown in Figure 2, the annular groove (or convex strip) turbulent high-efficiency cooling continuous casting mold is used in the structure of the billet continuous casting mold. As shown in Figure 3 and Figure 4, the longitudinal section and partial enlargement of the ring-shaped groove (or convex strip) turbulent-flow high-efficiency cooling continuous casting mold.

The annular groove (or convex strip) turbulent high-efficiency cooling continuous casting mold includes a water jacket 1, a copper mold 3, and a cooling water seam 2 formed between the water jacket and the copper mold, on the outer wall of the copper mold There are intermittently arranged transverse trapezoidal grooves, or it can also be said that intermittently arranged transverse trapezoidal convex lines are arranged on the outer wall of the copper crystallizer. The angle α between the two sides of the trapezoidal groove or the trapezoidal ridge is 30°-60°.

Example 2: Block-shaped convex turbulent-flow high-efficiency cooling continuous casting mold

As shown in Figure 5, the block-shaped turbulent-flow high-efficiency cooling continuous casting mold is used for the structure of the round billet continuous casting mold, and as shown in Figure 6, the block-shaped turbulent-flow high-efficiency cooling continuous casting mold is used for billet continuous casting The structure of the cast crystallizer.

The block-shaped turbulent-flow high-efficiency cooling continuous casting mold includes a water jacket 1, a cooling water seam 2, and a copper crystallizer 3; the cooling water seam 2 is formed between the water jacket 1 and the copper mold 3, and is formed on the outer wall of the copper mold There are intermittently arranged horizontal and vertical rectangular grooves on the top. On the surface of the outer wall of the copper crystallizer, lumpy protrusions are formed, so that uneven water seams are formed between the water jacket and the outer surface of the crystallizer covered with lumpy protrusions.

Numerical simulations were carried out for the flow state of the water flow in the water slots of the ordinary crystallizer and the annular groove (or convex strip) high-efficiency cooling crystallizer. As shown in Figure 7, the water flow in the water gap between the ordinary crystallizer and the water jacket is a schematic diagram of laminar flow. As shown in Figure 8, the water flow in the water gap between the cooling crystallizer and the water jacket in the annular groove (or convex line) is a schematic diagram of turbulent flow. Due to the change of the structure of the outer surface of the crystallizer, the flow state of the water flow in the water gap changes, from laminar flow to turbulent flow, so that all the water in the water gap participates in cooling, which in turn can improve the heat exchange between the crystallizer and cooling water efficiency. Through numerical simulation, it is proved theoretically that the structure of the turbulent cooling crystallizer is better than that of the ordinary crystallizer, and the cooling efficiency of the cooling water can be improved.

Claims (6)

1, the method for cooling water formation turbulent flow in a kind of continuous cast mold, the continuous cast mold that adopts water jacket, cooling water seam, Cu crystallizer to form, constitute the cooling water seam between water jacket and the Cu crystallizer, it is characterized in that: be provided with projection or groove in the Cu crystallizer outer wall surface, make and form rough water seam between water jacket and the crystallizer outer surface, when cooling water enters the cooling water seam, after cooling water runs into the projection or groove that the Cu crystallizer outer wall surface is provided with, the flow direction of a part of cooling water is changed, thereby cooling water flow with turbulence form.

2, a kind of turbulence type continuous cast mold, comprise water jacket (1), Cu crystallizer (3), constitute cooling water seam (2) between water jacket (1) and the Cu crystallizer (3), it is characterized in that: described Cu crystallizer outer wall surface is provided with projection or groove, makes and forms rough water seam between inner water sleeve and the crystallizer outer surface.

3, according to the described turbulence type continuous cast mold of claim 2, it is characterized in that: described Cu crystallizer outer wall surface is provided with is interrupted the horizontal trapezoid raised line or the groove of arranging.

4, according to the described turbulence type continuous cast mold of claim 3, it is characterized in that: the two sides angle α of described trapezoidal raised line or groove is 30 °～60 °.

5, according to the described turbulence type continuous cast mold of claim 2, it is characterized in that: the described Cu crystallizer outer wall surface horizontal and vertical groove of having arranged forms block projection in the Cu crystallizer outer wall surface.

6, according to the described turbulence type continuous cast mold of claim 5, it is characterized in that: the described Cu crystallizer outer wall surface horizontal and vertical trench cross section of having arranged is shaped as rectangle.

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