CN1718328A - Molten steel spin type continuous casting pouring basket - Google Patents

Abstract

A molten steel spinning type conticasting tundish able to effectively separate non-metal impurities and prevent secondary oxidizing and slag collection is composed of main body, long sprue, retaining wall, retaining dam, immersible sprue, cyclone chamber and circular tangent inlet of molten steel.

Description

A kind of molten steel spin type continuous casting tundish

Technical field

The present invention relates to metallurgical technology field, be specifically related to a kind of intermediate equipment in the steel-making continuous casting production.

Background technology

Tundish is needed a kind of intermediate equipment in the steel-making continuous casting production procedure, is by the linking point of intermittently operated to continued operation in the STEELMAKING PRODUCTION.It is one of visual plant that improves output of steel, quality and production efficiency.

The 1950's, continuous casting technology grows up as the steel and iron industry marked achievement, is characterized in that technical process speed is fast, and investment is concentrated.Whole world continuous casting ratio only was 5.6% in 1970, and to nineteen ninety whole world continuous casting ratio reached 62.4%, the continuous casting ratio of some industrially developed country has surpassed 95%.Global continuous casting ratio was 72.4% in 1994, and many in the world in recent years steel mills have replaced die casting production with sequence casting in succession.By 1994, realize that the country of sequence casting has reached 24.Continuous casting technology is not late in China's starting, but there have been suitable gap in slower development and developed country, and in the later stage eighties, under the policy of " with the continuous casting is the center, makes steel to be the basis, and equipment is for guaranteeing " instructed, the continuous casting technology of China had had swift and violent development.For efficient, the continuously quick sustainable development of China's iron and steel is laid a good foundation.

Tundish as metallurgical reaction no matter for continuous casting still be for guaranteeing the molten steel quality smoothly, its effect all be can not ignore.It has been generally acknowledged that tundish plays following three kinds of effects:

1, shunting action.For multiple-strand caster, molten steel is shunted by many mouths of a river tundish.

2, connect the effect of watering.When sequence casting, the molten steel of tundish storage can play the effect of linking when changing ladle.

3, depressurization.The molten steel liquid level has 5～6m in the ladle, and the impulsive force that molten steel potential energy produces is very big, and the amplitude that changes in casting cycle is also bigger.The tundish liquid level is lower than ladle and amplitude that change is little, therefore can stablize the molten steel casting cycle, reduces steel stream washing away the crystallizer solidified shell.

Tundish is molten steel casting blank last big splendid attire equipment before, in order to improve steel quality, reduce in the steel and be mingled with, people have adopted a new technology, promptly flow control device and electromagnetic field are set at the tundish place, making time of staying increase or the generation speed of molten steel in tundish is rotatablely moving between 40～50rpm, impel the nonmetal inclusion in the molten steel to obtain polymerization, adhesion and come-up, the molten steel that assurance enters in the crystallizer has higher degree of purity, thereby obtains the high-quality strand of composition homogeneous.

Facts have proved that utilization adds electromagnetic field and impels the molten steel in the tundish to obtain rotational flow field, improves for steel quality and can bring into play obvious effect really, but obviously increased equipment investment and operating cost, is unfavorable for generally use in steel mill's continuous casting is produced.

Summary of the invention

Weak point at existing tundish the invention provides a kind of molten steel spin type continuous casting tundish, to reduce equipment investment and the operating cost that steel-making continuous casting is produced.

The present invention improves the tundish of existing steel-making continuous casting production usefulness, in tundish, design cylinder or truncated cone-shaped swirling chamber structure that the bottom has molten steel tangent line inlet, swirling chamber is located at the big bag beam of tundish inner bottom surface position, make and inject molten steel in the tundish from ladle and when the swirling chamber bottom tangentially enters swirling chamber, utilize self potential energy in swirling chamber, to produce rotational flow, MOLTEN STEEL FLOW can produce the rotational flow field of 5～60rpm in swirling chamber in actual casting cycle, utilizes centripetal force to remove the purpose that is mingled with and controls turbulent flow thereby reach.

Utilize self potential energy of molten steel in the big bag, the guiding molten steel enters the swirling chamber body interior along the swirling chamber molten steel tangent line inlet that is attached thereto after by long nozzle, relies on the potential energy of molten steel and the kinetic energy that flows, and can make molten steel produce rotational flow.This is because at first because the restriction of swirling chamber main body wall makes the kinetic energy major part of molten steel dissipate in swirling chamber inside, have less kinetic energy and turbulivity at the place, upper edge of swirling chamber, for the mobile generation favorable influence of mild barricade and retaining back, dam.Secondly, because the centrifugal force that produces that rotatablely moves produces different effects for the different molten steel of density with nonmetal inclusion, the less nonmetal inclusion of density " is pressed to " center of swirling chamber, thereby the polymerization that is beneficial to nonmetal inclusion is grown up and floated.Entad the particle force analysis is as follows in the field of force.

When particle was in the Stokes district, it was 3 π μ du that particle is subjected to drag force _r, u wherein _rBe radial motion speed, ω is an angular velocity of rotation, and ρ is a fluid density, ρ _sBe grain density, d is a particle diameter.

The stressed equation of particle: $\frac{\mathrm{\&pi;}}{6}{\mathrm{<figure-callout\; id="3"\; label="d"\; filenames="A20051004699400081.png"\; state="\{\{state\}\}">d</figure-callout>}}^3{\mathrm{\&rho;}}_s\frac{{\mathrm{du}}_r}{\mathrm{dt}}=\frac{\mathrm{\&pi;}}{6}{d}^3(\mathrm{\&rho;}-{\mathrm{\&rho;}}_s){\mathrm{\&omega;}}^2(R_0-r)-3{\mathrm{\&pi;\&mu;du}}_r.$

Order $\frac{{\mathrm{du}}_r}{\mathrm{dt}}=\frac{d^2\mathrm{<figure-callout\; id="2"\; label="r\; d\; t"\; filenames="A20051004699400081.png"\; state="\{\{state\}\}">r</figure-callout>}}{d{t}^{}},$ $u_r=\frac{\mathrm{dr}}{\mathrm{dt}},$ Finding the solution entad moving displacement and the time relationship that this equation can obtain particle is:

$r=R_0+\frac{R_0}{r_1-r_2}(r_2{e}^{r_{1}t}-r_1{e}^{r_{2}t}).$ R wherein ₁And r ₂Be two characteristic roots of stressed equation.

Molten steel spin type continuous casting tundish swirling chamber design parameter of the present invention is as follows:

1. experimental study is with molten steel spin type continuous casting tundish swirling chamber design parameter

(1) the swirling chamber design parameter of You Huaing

Cylindrical swirling chamber: interior diameter: 100～400mm, ratio of height to diameter scope 0.48～4.0, optimal proportion is about 2; Truncated cone-shaped swirling chamber: the internal diameter 100～400mm that goes to the bottom, the upper base internal diameter/internal diameter 0.5～1.0 of going to the bottom, high 100～400mm; Swirling chamber bottom tangent direction inlet diameter is identical with the long nozzle diameter, and rounding off.

(2) operating parameter and result of use

Swirling chamber is placed in tundish beam district, is that 2～3m and tundish injection flow are 1.5～3.5m at big bag liquid level ³Under the condition of/h, can obtain the rotary speed of molten steel 10～100rpm in swirling chamber.

2. industrial production is with molten steel spin type continuous casting tundish swirling chamber design parameter

(1) the swirling chamber design parameter of You Huaing

To the tundish of different capabilities and shape, the design parameter of swirling chamber is as follows.

Cylindrical swirling chamber: interior diameter 250～1000mm, ratio of height to diameter scope 0.48～4.0, optimal proportion is about 2;

The truncated cone-shaped swirling chamber: the internal diameter 250～1000mm that goes to the bottom, the upper base internal diameter is 0.5～1.0 with the ratio of the internal diameter of going to the bottom, high 250～1000mm;

Swirling chamber bottom tangent direction inlet diameter is identical with the long nozzle diameter, and rounding off.

(2) operating parameter and result of use

Swirling chamber is placed in tundish beam district, is that 4～6m and molten steel injection flow are 15～35m at big bag liquid level ³Under the condition of/h, can obtain the rotary speed of molten steel 5～60rpm in swirling chamber.

The selection of the ratio of swirling chamber interior diameter size and height is according to the capacity of tundish and to require production capacity (injection flow) definite, and is big for volume, the tundish that injection rate is fast, and principle is selected larger-diameter swirling chamber for use.

Molten steel spin type continuous casting tundish of the present invention adopts exclusive swirling chamber flow control device design, can effectively reduce the Turbulent Kinetic of fluid, makes the mobile state that approaches the laminar flow steady flow in the tundish; Rotary speed reaches 5～60rpm in the swirling chamber, can effectively separate nonmetal inclusion, can prevent to wrap greatly the secondary oxidation and the volume slag of beam; It is simple to adopt equipment of the present invention to carry out steel-making continuous casting producing process, and it is low to transform existing technology cost, is easy to suitability for industrialized production, has broad application prospects, and is particularly suitable for the steel grade that the quality of production is had relatively high expectations.

Description of drawings

Fig. 1 is the front sectional elevation of molten steel spin type continuous casting tundish, and wherein (a) is the front sectional elevation of the molten steel spin type continuous casting tundish of cylindrical swirling chamber, (b) is the front sectional elevation of the molten steel spin type continuous casting tundish of truncated cone-shaped swirling chamber.

Fig. 2 is the vertical view of molten steel spin type continuous casting tundish.

Fig. 3 is a swirling chamber entrance structure cutaway view Amplified image.

Among the figure: 1 is the tundish body, 2 long nozzles, 3 swirling chamber main bodys, 4 molten steel tangent lines inlet, 5 barricades, 6 retaining dams, 7 submersed nozzles, D ₁, D ₂, H, H ₁, L ₁, L ₂, W ₁, W ₂, L ₃, L ₄, L ₅, X ₁And Y ₁Be the design parameter of tundish, D ₁The interior diameter of cylindrical swirling chamber, H ₁The height of swirling chamber, D ₂Long nozzle and submersed nozzle diameter, L ₁Tundish upper port length, L ₂Tundish bottom surface length, W ₁The tundish bottom width, W ₂Tundish upper port width, L ₃The X of barricade is to location dimension, L ₄The retaining dam X to location dimension, L ₅The X of submersed nozzle is to location dimension, X ₁And Y ₁Be the go to the bottom location dimension of wall of swirling chamber centre distance, the X-axis of X coordinate system, the Y-axis of Y coordinate system.

The specific embodiment

Embodiment 1

As shown in drawings, the molten steel spin type continuous casting tundish of using for experimental study of present embodiment is compared with the tundish that generally uses at present, and its something in common is that tundish is provided with parts such as tundish body 1, long nozzle 2, barricade 5, retaining dam 6, submersed nozzle 7.Difference is to be provided with a cylindrical swirling chamber below big bag beam position, tundish bottom surface, and this swirling chamber main body 3 links to each other with big bag by long nozzle 2, and the swirling chamber bottom has circular molten steel tangent line inlet 4 along the tangent to periphery direction.Design parameter can be determined by following data:

Critical size	X 1	Y 1	L 1	L 2	W 1	W 2	H	L 3	L 4	L 5	D 1	H 1	D 2
														Numerical value, mm	435	390	1980	1680	830	470	485	650	950	95	200	260	30

Adopt this tundish to be used for experimental study, at flow 1.5～3.5m ³Under the condition of/h, obtaining the molten steel rotary speed is 10～100rpm.By numerical simulation and measuring, can judge that this tundish has good control stream and removal and is mingled with function.

Embodiment 2

As shown in drawings, the molten steel spin type continuous casting tundish of using for industrial production of present embodiment is compared with the tundish that generally uses at present, and its something in common is that tundish is provided with parts such as tundish body 1, long nozzle 2, barricade 5, retaining dam 6, submersed nozzle 7.Difference is to be provided with a cylindrical swirling chamber below big bag beam position, tundish bottom surface, and this swirling chamber main body 3 links to each other with big bag by long nozzle 2, and the swirling chamber bottom has circular molten steel tangent line inlet 4 along the tangent to periphery direction.Design parameter can be determined by following data:

Critical size	X 1	Y 1	L 1	L 2	W 1	W 2	H	L 3	L 4	L 5	D 1	H 1	D 2
														Numerical value, mm	1088	975	4950	4200	2080	1175	1212	1625	2380	238	500	650	75

Adopt this tundish to be used for steel-making continuous casting production, at flow 15～35m ³Under the condition of/h, obtaining rotary speed is 5～60rpm.Use the expection of this tundish to reduce and be mingled with 10%, be mingled with function thereby played good removal.

Embodiment 3

As shown in drawings, the molten steel spin type continuous casting tundish of using for experimental study of present embodiment is compared with the tundish that generally uses at present, and its something in common is that tundish is provided with parts such as tundish body 1, long nozzle 2, barricade 5, retaining dam 6, submersed nozzle 7.Difference is to be provided with a truncated cone-shaped swirling chamber below big bag beam position, tundish bottom surface, and this swirling chamber main body 3 links to each other with big bag by long nozzle 2, and the swirling chamber bottom has circular molten steel tangent line inlet 4 along the tangent to periphery direction.Design parameter can be determined by following data:

Critical size	X 1	Y 1	L 1	L 2	W 1	W 2	H	L 3	L 4	L 5	D 1	H 1	D 2	Upper base
															Numerical value, mm	435	390	1980	1680	830	470	485	650	950	95	200	260	30	100

Adopt the molten steel spin type continuous casting tundish of present embodiment, at flow 1.5～3.5m ³Under the condition of/h, obtaining the molten steel rotary speed is 10～100rpm.By numerical simulation and measuring, can judge that this tundish has good control stream and removal and is mingled with function.

Embodiment 4

As shown in drawings, the molten steel spin type continuous casting tundish of using for industrial production of present embodiment is compared with the tundish that generally uses at present, and its something in common is that tundish is provided with parts such as tundish body 1, long nozzle 2, barricade 5, retaining dam 6, submersed nozzle 7.Difference is to be provided with a truncated cone-shaped swirling chamber below big bag beam position, tundish bottom surface, and this swirling chamber main body 3 links to each other with big bag by long nozzle 2, and the swirling chamber bottom has circular molten steel tangent line inlet 4 along the tangent to periphery direction.Design parameter can be determined by following data:

Critical size	X 1	Y 1	L 1	L 2	W 1	W 2	H	L 3	L 4	L 5	D 1	H 1	D 2	Upper base
															Numerical value, (mm)	1088	975	4950	4200	2080	1175	1212	1625	2380	238	500	650	75	250

Adopt the molten steel spin type continuous casting tundish of present embodiment, at flow 15～35m ³Under the condition of/h, obtaining the molten steel rotary speed is 5～60rpm.Use the expection of this tundish to reduce and be mingled with 13%, be mingled with function thereby played good removal.

Claims (3)

1, a kind of molten steel spin type continuous casting tundish, comprise tundish body, long nozzle, barricade, retaining dam, submersed nozzle, it is characterized in that also comprising swirling chamber and circular molten steel tangent line inlet, swirling chamber is arranged on below, big bag beam position, tundish bottom surface, the swirling chamber main body links to each other with big bag by long nozzle, and the swirling chamber bottom has circular molten steel tangent line inlet along the tangent to periphery direction.

2, according to the described molten steel spin type continuous casting tundish of claim 1, it is characterized in that swirling chamber is cylindrical swirling chamber or truncated cone-shaped swirling chamber, the design parameter of swirling chamber is as follows:

Cylindrical swirling chamber, interior diameter 250～1000mm, ratio of height to diameter scope 0.48～4.0;

The truncated cone-shaped swirling chamber, the internal diameter 250～1000mm that goes to the bottom, the upper base internal diameter is 0.5～1.0 with the ratio scope of the internal diameter of going to the bottom, high 250～1000mm.

3, according to the described molten steel spin type continuous casting tundish of claim 1, it is characterized in that the swirling chamber bottom is identical with the long nozzle diameter along the circular molten steel tangent line inlet diameter of tangent to periphery direction, and rounding off.

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