CN-121975988-A - Converter tapping slag blocking method and device based on furnace mouth sealing and in-furnace pressure control

CN121975988ACN 121975988 ACN121975988 ACN 121975988ACN-121975988-A

Abstract

The invention provides a converter tapping slag blocking method and device based on furnace mouth sealing and in-furnace pressure control, wherein the method comprises the following steps of S1, moving a horn-shaped sealing cover to a converter mouth when converter body tapping, enabling the horn-shaped sealing cover to be in butt joint with the converter mouth, starting a floating sealing assembly to form an airtight cavity, S2, applying and maintaining set gauge pressure delta P to an inner cavity of the converter body through an air pressure adjusting unit connected with the airtight cavity so as to enable molten steel to flow out of a converter tapping hole, and simultaneously inhibiting slag liquid from flowing out along with the molten steel, S3, dynamically adjusting the set gauge pressure delta P according to a converter dip angle, a molten steel liquid level, a slag layer thickness and tapping flow in the tapping process, S4, removing the airtight cavity after tapping is finished, and enabling the horn-shaped sealing cover to withdraw from the converter mouth. The invention only enters the working position when converting is finished and tapping is performed by pouring, realizes slag blocking control without introducing foreign matters or impacting a tapping hole, and combines high-temperature visualization and intrinsic safety.

Inventors

LU ZHIHAO
TAN ZHENJUN
XU HAILIANG
WANG CHUNWEI
CAO LIN

Assignees

鞍钢股份有限公司

Dates

Publication Date: 20260505
Application Date: 20260209

Claims (10)

1. The converter tapping slag blocking method based on furnace mouth sealing and in-furnace pressure control is characterized by comprising the following steps of: S1, when converting is finished and the converter body is tapped, moving the horn-shaped sealing cover to the converter mouth, adjusting the angle of the horn-shaped sealing cover through a follow-up positioning mechanism on the horn-shaped sealing cover, enabling the horn-shaped sealing cover to be in butt joint with the converter mouth, and starting the floating sealing assembly to form an airtight cavity; s2, applying and maintaining a set gauge pressure delta P to the inner cavity of the converter body through an air pressure adjusting unit connected with the airtight cavity so as to enable molten steel to flow out of a steel tapping hole of the converter, and simultaneously inhibiting slag from flowing out along with the molten steel; s3, dynamically adjusting and setting gauge pressure delta P according to the dip angle of the converter, the liquid level of molten steel, the thickness of a slag layer and the tapping flow in the tapping process; And S4, after tapping, releasing the airtight cavity, and enabling the horn-shaped sealing cover to be removed from the converter mouth.
2. The converter tapping slag stopping method based on furnace mouth sealing and in-furnace pressure control according to claim 1, wherein the set gauge pressure Δp is controlled in segments according to tapping process, comprising: The first setting range is that positive pressure is applied to accelerate the outflow of molten steel when the liquid level is higher than the critical height in the early stage of the tapping process; The second setting range is that when the liquid level is close to the critical height at the end of tapping, the pressure is reduced to slight negative pressure so as to reduce the tapping flow rate and inhibit vortex generation; A third setting range, namely increasing negative pressure to cut off fluid when slag liquid flowing out is detected, and matching with converter tilting back; The tapping flow rate is as follows: Wherein h eff is the effective height of the molten steel surface relative to the tap hole, delta P is the gauge pressure applied in the furnace, and rho s is the density of the molten steel; the critical height H crit of the vortex is positively correlated with the flow velocity v, and the expression is: H crit =k·v α ·d wherein k is an empirical coefficient, alpha is in the range of 0.4 to 1.0, and d is the diameter of the tap hole; the control window logic for setting the gauge pressure delta P is as follows: 。
3. the converter tapping slag stopping method based on furnace mouth sealing and furnace internal pressure control according to claim 1, wherein in S3, the dynamic regulation is a sectional closed-loop control, namely, the set gauge pressure delta P is firstly lifted to a first set range, and is lifted to a second set range and a third set range section by section according to tapping process/dip angle/interface identification to inhibit slag escape; The tapping inclination angle range of the first setting range is 75-90 degrees, the tapping inclination angle range of the second setting range is 90-102 degrees, and the tapping inclination angle range of the second setting range is more than 102 degrees.
4. The converter tapping slag stopping method based on furnace mouth sealing and in-furnace pressure control according to claim 1, wherein in S3, when the tapping hole slag-off inspection device detects that there is a slag-liquid breakthrough risk through visual/thermal imaging, a short-time negative pressure increasing operation is performed to temporarily increase the in-furnace gauge pressure difference to the strengthening pressure P boost and fall back after maintaining for a predetermined time.
5. The converter tapping slag stopping device based on the furnace mouth seal and the in-furnace pressure control is used for realizing the converter tapping slag stopping method based on the furnace mouth seal and the in-furnace pressure control according to any one of claims 1-4, and is characterized by comprising a horn-shaped sealing cover, wherein the horn-shaped sealing cover is connected with a converter mouth at the front end of a converter body by utilizing a floating sealing assembly at an opening part and gradually convergent from back to front, and is fixed on a wheel type self-walking chassis by a follow-up positioning mechanism; The side wall of the rear end cover body of the horn-shaped sealing cover is provided with an air exhaust channel, the side wall of the front end cover body of the horn-shaped sealing cover is provided with a pressure relief channel, the front of the horn-shaped sealing cover is connected with a first vision system, the first vision system is provided with an air curtain cooling self-cleaning device, and the second vision system is arranged on a wheel type self-walking chassis; The camera is arranged in the first vision system and is opposite to the horn-shaped sealing cover, an explosion-proof visual window is arranged between the interior of the first vision system and the horn-shaped sealing cover, and the camera is electrically connected with the second vision system; The follow-up positioning mechanism comprises a fixed column and two hydraulic columns, the middle part of the fixed column is rotationally connected with the middle part of the horn-shaped sealing cover, the two hydraulic columns are respectively arranged in front of and behind the fixed column, and the upper part of the hydraulic column is rotationally connected with the horn-shaped sealing cover; The wheel type self-walking chassis is provided with a controller, and the controller is electrically connected with the wheel type self-walking chassis, the follow-up positioning mechanism, the air suction channel and the pressure relief channel.
6. The converter tapping slag blocking device based on furnace mouth sealing and in-furnace pressure control according to claim 5, wherein the converter tapping slag blocking device comprises a converter tapping hole arranged at the front lower end of the converter body.
7. The converter tapping slag blocking device based on furnace mouth sealing and in-furnace pressure control according to claim 5, wherein the rear end opening of the horn-shaped sealing cover is larger than the furnace mouth of the converter.
8. The converter tapping slag blocking device based on furnace mouth sealing and furnace internal pressure control according to claim 5 is characterized by comprising the wheel type self-walking chassis which is arranged on the ground, and a limiter is arranged on the rear bottom surface of the wheel type self-walking chassis.
9. The converter tapping slag blocking device based on furnace mouth sealing and furnace internal pressure control according to claim 5 is characterized by comprising a refractory composite material arranged on the inner wall of a cover body of a horn-shaped sealing cover, a double-layer cooling jacket is arranged outside the horn-shaped sealing cover, and the air curtain cooling self-cleaning device is an annular air spraying ring.
10. The converter tapping slag blocking device based on furnace mouth sealing and in-furnace pressure control according to claim 5, wherein a floating seal assembly is arranged between the converter mouth and a horn-shaped sealing cover, and the floating seal assembly comprises: the water cooling base is integrated on the frame of the horn-shaped sealing cover, and a circulating water cooling channel is arranged in the water cooling base and used for forcedly reducing the temperature of the sealing area; The flexible high-temperature sealing component is arranged on one side of the water cooling base facing the converter mouth and is used for being tightly attached to the converter mouth flange in an inflated or pressed state; The external sealing mechanism is positioned on the radial outer side of the flexible high-temperature sealing member, comprises a double-channel sealing structure and a dustproof scraping plate, wherein the double-channel sealing structure and the dustproof scraping plate are sequentially arranged along the butt joint direction, and the external sealing mechanism is used for blocking dust and providing auxiliary sealing for a butt joint interface between the horn-shaped sealing cover and the converter mouth.

Description

Converter tapping slag blocking method and device based on furnace mouth sealing and in-furnace pressure control Technical Field The invention relates to the technical field of ferrous metallurgy, in particular to a converter tapping slag blocking method and device based on furnace mouth sealing and in-furnace pressure control. Background In the converter steelmaking process, slag blocking operation in the tapping stage is a key link for guaranteeing the cleanliness of molten steel. The method aims to prevent or reduce slag in a furnace from flowing into a steel ladle along with molten steel, thereby avoiding casting blank defects, alloy yield reduction and load increase of subsequent refining procedures caused by slag inclusion. The traditional slag blocking concept mainly relies on the arrangement of a physical barrier or the application of local turbulence near the tap hole to achieve mechanical separation of the slag. At present, the slag blocking technology commonly adopted in the industry mainly comprises a slag blocking dart, a slag blocking ball and other input type devices, and a slag blocking slide plate and other mechanical valve port mechanisms. These methods all fall into the category of direct interception or interference on the steel flow path. In addition, there have also been attempts to form a gas curtain by means of aerodynamic forces to hinder the slag flow by arranging a gas permeable element in the region of the tap hole. The common feature of the above prior art is that its range of action is concentrated in the vicinity of the tap hole, directly influencing the state of motion of the steel/slag two-phase flow by introducing external objects or energy. However, these prior art techniques have significant limitations. Firstly, solid foreign matters such as slag darts, balls and the like are put into the steel flow, which may become a new pollution source, influence the purity of the molten steel, and increase the cost due to the material consumption. Secondly, the slag blocking effect of the method is seriously dependent on operation experience, is extremely sensitive to variables such as the inclination angle of a converter, the liquid level height, the thickness of a slag layer, the flow state of steel flow and the like, and has higher slag blocking failure rate when the condition of a steel tapping hole is poor, the vortex effect is obvious or the slag property fluctuates. Moreover, most of the prior art is passive or open-loop control, so that real-time and self-adaptive closed-loop coupling control is difficult to realize with multiple parameters such as inclination angle, liquid level, flow and the like which are dynamically changed in the tapping process, the slag blocking window is narrow, and the stability is insufficient. Finally, although solid foreign matters are not introduced in the partial pneumatic slag blocking scheme, the action range is limited, and the service life of the steel-tapping hole refractory can be adversely affected. Therefore, a new method and device for blocking slag, which do not pollute molten steel, have strong adaptability and can realize intelligent active control, are needed. Disclosure of Invention According to the technical problems that the prior slag blocking technology needs to introduce physical foreign matters into steel flow and cannot be coupled with the tapping process in a multivariable real-time manner, so that molten steel is polluted, slag blocking is unstable and manual experience is relied on, the converter tapping slag blocking method and device based on furnace mouth sealing and in-furnace pressure control are provided. According to the invention, the furnace mouth is rapidly sealed through the movable device and a controllable airtight cavity is formed during tapping, and the gauge pressure in the cavity is dynamically regulated to a physical window calculated based on the steel/slag static pressure difference, so that non-contact and self-adaptive steel slag separation is realized, and the effects of realizing stable and efficient slag-free tapping and improving the cleanliness of molten steel and the service life of the tapping hole on the premise of not introducing foreign matters into a steel flow and not modifying a converter body are achieved. The invention adopts the following technical means: A converter tapping slag blocking method based on furnace mouth sealing and in-furnace pressure control comprises the following steps: S1, when converting is finished and the converter body is tapped, moving the horn-shaped sealing cover to the converter mouth, adjusting the angle of the horn-shaped sealing cover through a follow-up positioning mechanism on the horn-shaped sealing cover, enabling the horn-shaped sealing cover to be in butt joint with the converter mouth, and starting the floating sealing assembly to form an airtight cavity; s2, applying and maintaining a set gauge pressure delta P to the inner cavity of the converte