Continuous casting cooling bed safety device

Abstract

This application relates to a safety device for a continuous casting cooling bed, which includes a plurality of safety units arranged continuously to bear the weight of the billet. It is characterized in that: the safety unit includes a cooling bed frame, an inner roller rotatably installed on the cooling bed frame through an inner roller shaft, an outer sleeve roller sleeved on the top surface of the inner roller, and the upper surface of the outer sleeve roller protrudes from the cooling bed frame; a cold air hollow shaft is further arranged on the cooling bed frame, and a cold air flow significantly lower than the surface temperature of the billet circulates therein; a cold air shaft housing is rotatably arranged outside the cold air hollow shaft through a bearing, and the outer surface of the cold air shaft housing is closely attached to the area where the outer sleeve roller contacts the billet and rotates with the outer sleeve roller under the drive of static friction; a slag receiving hopper is arranged along the contact line below the contact position between the cold air shaft housing and the outer sleeve roller. This application does not damage the surface of the supporting roller to clean the dense oxide layer, improves the safety of billet transportation; the ventilation shaft enables better control of the heat dissipation of the billet and is suitable for various requirements.

Description

Technical Field

[0001] This application relates to the field of steelmaking equipment, and particularly to a safety device for a continuous casting cooling bed. Background Art

[0002] Continuous casting is a common method for the production of various steel products. Briefly speaking, it refers to the process of directly pouring molten steel into a mold, continuously pulling it out by a straightening machine, bending rolls, leveling rolls, etc. before it is completely solidified in the mold, cutting it into billets by a cutting device, and then transporting it to the rolling workshop by a cooling bed. During the transportation of the billets on the cooling bed, they slowly dissipate heat from the red-hot state, and the surface layer reacts with air to form a thin and brittle scale, which continuously falls off during transportation. The size of the billets varies greatly according to the requirements of downstream rolling products and can weigh several tons. The scale shed from the billets falls on the cooling bed rollers and is densely adhered to the roller surface under the pressure of gravity, causing a change in the friction coefficient with the billets. In the light case, it causes uneven transportation progress and affects the production line rhythm; in the heavy case, it causes the billets to slide and collide with the retaining wall, posing a great safety hazard.

[0003] Some solutions have emerged for the problem of scale adhesion failure on the rollers, such as CN110899344B, which uses slag scraping teeth that are tightly pressed against the rollers to synchronously clean and collect the slag adhered to the roller surface, playing a safety protection function (description attached Figure 1-2 ). However, in such solutions, firstly, for the slag compacted by a very large weight, a relatively large pressure is required to make the scraping edge effective for slag cleaning; but after the pressure increases, the wear on the rollers also increases, and the fixed slag scraping groove will become disengaged after continuous wear and cannot function; secondly, the action of the scraping edge on the roller surface will also change the friction coefficient of the roller, and even if the slag is cleaned, the risk of billet sliding mentioned above may still occur.

[0004] On the other hand, when the cooling bed is preparing to roll the billets, reheating is also required to make the billets reach a rollable state. Depending on the equipment and rolling requirements of each unit, sometimes the billets need to be cooled as much as possible before reheating, and sometimes they need to be kept warm as much as possible. A batch of solutions for collecting and converting waste heat or insulating the billets have also emerged. These solutions all start from the contact surface between the billets and the air. Since the billets are in direct contact with the cooling bed rollers and both are metal conductors, the current rollers cannot control the temperature of the billets, which also affects the production efficiency. Summary of the Invention

[0005] (I) Technical Problems

[0006] 1. Clean the slag without damaging the rollers and eliminate potential safety hazards;

[0007] 2. Improve the function of the rollers to dissipate heat or keep warm the billets as needed.

[0008] (2) Technical solution

[0009] The continuous casting cooling bed safety device according to the present application includes a plurality of continuously arranged safety units for bearing the weight of billets, and is characterized in that: each safety unit includes a cooling bed frame, inner rollers rotatably mounted on the cooling bed frame through inner roller shafts, outer sleeve rollers sleeved on the top surfaces of the inner rollers, and the upper surfaces of the outer sleeve rollers protrude from the cooling bed frame; a cold air hollow shaft is further arranged on the cooling bed frame, and cold air flow significantly lower than the surface temperature of the billet flows through it; a cold air shaft housing is rotatably arranged outside the cold air hollow shaft through bearings, and the outer surface of the cold air shaft housing closely contacts the area of the outer sleeve roller after contacting the billet and rotates with the outer sleeve roller under the drive of static friction; a slag receiving hopper is arranged along the contact line below the contact position between the cold air shaft housing and the outer sleeve roller.

[0010] Further, push-pull devices are arranged at both ends of the cold air hollow shaft to adjust the degree of pressing it against the outer sleeve roller through the cold air shaft housing.

[0011] Further, hollow ventilation shaft I and ventilation shaft II are further arranged along the axial direction inside the outer sleeve roller, ventilation shaft housings I and II are arranged outside the peripheries of ventilation shaft I and ventilation shaft II through bearings, and fluids at a specific temperature flow through ventilation shaft I and ventilation shaft II; the outer surfaces of ventilation shaft housings I and II abut against the inner wall of the outer sleeve roller and rotate therewith.

[0012] Further, the positions where ventilation shaft housing I and ventilation shaft housing II contact the inner wall of the outer sleeve roller are downstream of the contact position of the cold air shaft housing.

[0013] Further, a partition plate for separating the ventilation shaft I assembly and the ventilation shaft II assembly is arranged inside the outer sleeve roller, heat-conducting filler is filled in the area of the contact line between ventilation shaft I and ventilation shaft II and the outer sleeve roller; heat-insulating filler is filled between the outer surface of the outer sleeve roller and the cooling bed frame.

[0014] Further, scraping gratings I and II with comb-shaped teeth are arranged along the length direction on the side wall of the slag receiving hopper, scraping grating I is pulled by an elastic member to abut against the outer surface of the outer sleeve roller, and a ball is arranged at each contact point; scraping grating II is pulled by an elastic member to abut against the outer surface of the cold air shaft housing, and a ball is arranged at each contact point.

[0015] (3) Beneficial effects

[0016] The present application realizes the cleaning of the compacted dense oxide layer without damaging the surface of the idler roller, improves the safety of billet transportation, and at the same time, the design of multiple ventilation shafts enables better control of the heat dissipation of the billet and can be applicable to various requirements. Description of the drawings

[0017] Figure 1 Schematic diagram of the slag cleaning device for the cooling bed in the prior art CN110899344B;

[0018] Figure 2 is Figure 1 Side view sectional view;

[0019] Figure 3 Overall schematic diagram according to the solution of the present application;

[0020] Figure 4 is Figure 3 Partial enlarged view of each safety unit in;

[0021] Figure 5 is Figure 4 Partial enlarged view;

[0022] Figure 6 is Figure 5 Partial enlarged view.

[0023] Reference numerals

[0024] 1. Steel billet

[0025] 2. Cooling bed frame

[0026] 3. Inner roller

[0027] 4. Inner roller shaft

[0028] 5. Outer sleeve roller

[0029] 6. Cold air hollow shaft

[0030] 7. Bearing

[0031] 8. Cold air shaft housing

[0032] 9. Ventilation shaft I

[0033] 10. Bearing

[0034] 11. Ventilation shaft housing I

[0035] 12. Ventilation shaft II

[0036] 13. Bearing

[0037] 14. Ventilation shaft housing II

[0038] 15. Thermal insulation filling

[0039] 16. Heat conduction filling

[0040] 17. Partition board

[0041] 18. Pulling grate I

[0042] 19. Slag receiving hopper

[0043] 20. Drag grate II

[0044] 21. Ball Detailed implementation manners

[0045] The present invention will be further described below in conjunction with embodiments.

[0046] As Figure 3 shown, the continuous casting cooling bed safety device according to the present application includes a plurality of continuously arranged safety units for bearing the weight of the billet 1, and is characterized in that: the safety unit includes a cooling bed frame 2, an inner roller 3 rotatably mounted on the cooling bed frame 2 through an inner roller shaft 4, an outer roller 5 sleeved on the top surface of the inner roller, and the upper surface of the outer roller shaft 5 protrudes from the cooling bed frame; a cold air hollow shaft 6 is further arranged on the cooling bed frame 2, and a cold air flow significantly lower than the surface temperature of the billet circulates therein; a cold air shaft housing 8 is rotatably arranged outside the cold air hollow shaft through a bearing 7, and the outer surface of the cold air shaft housing 8 is closely attached to the area after the outer sleeve roller 5 contacts the billet and rotates with the outer sleeve roller 5 under the drive of static friction; a slag receiving hopper 19 is arranged along the contact line below the contact position between the cold air shaft housing and the outer sleeve roller.

[0047] In this solution, the form of the carrying roller is improved and consists of an inner roller and an outer sleeve roller. The inner roller is completely installed by a roller shaft, while the outer sleeve roller has a certain degree of flexibility. However, from the outside of the frame, the protruding part of the outer sleeve roller is similar to the carrying roller part of the prior art CN110899344B; the key point is that after the outer sleeve roller bears the billet and contacts it, a dense scale will also adhere to its surface, and its temperature can reach basically the same as that of the billet during continuous conveying; at this time, a cold air hollow shaft is arranged in the area after its contact, and a cold air flow is conveyed therein, and the temperature of the cold air shaft housing on its outer surface is significantly low. After the cold air shaft housing abuts against the surface of the outer sleeve roller, the steel slag layer shrinks due to cold and is broken and peeled off.

[0048] In this process, the outer sleeve roller will also cool down and thermally expand and contract. However, since it is sleeved outside the traditional inner roller, its diameter is larger, and the linear degree of cold shrinkage is not obvious. Also because it has a certain degree of flexibility in installation, it has little impact on conveying. At the same time, the larger diameter of the outer sleeve roller also makes there be a certain transition between the hot part and the cold part on the circumference of the outer sleeve roller, reducing metal fatigue caused by frequent temperature changes.

[0049] If the inner roller directly contacts the cold air shaft housing, because it is cylindrical, the heat dissipation efficiency is low, and at the same time, there are simultaneous cold and hot alternating effects of the billet and the cold air shaft, which is extremely easy to cause thermal fatigue failure.

[0050] Moreover, the cold air shaft housing is rotatably arranged on the cold air hollow shaft through a bearing, and it can rotate with the outer sleeve roller without relative movement, which will not affect the surface roughness of the outer sleeve roller, that is, it will not affect its friction coefficient with the billet.

[0051] Furthermore, pusher devices are arranged at both ends of the cold air hollow shaft to adjust the degree of pressing against the outer sleeve roller through the cold air shaft housing.

[0052] During the process of the billet being conveyed on the cooling bed, it dissipates heat to the air and the roller with a similar temperature, and it is actually in a slow annealing state. If the outer sleeve roller cooled by the cold air hollow shaft contacts the bottom of the billet in the cooling state, it actually undergoes local quenching, which will still have an adverse effect on the subsequent processes. Therefore,

[0053] Furthermore, a hollow ventilation shaft I (9) and a ventilation shaft II (12) are arranged along the axial direction inside the outer sleeve roller. The outer peripheries of the ventilation shaft I and the ventilation shaft II are provided with a ventilation shaft housing I and a ventilation shaft housing II through bearings 10 and 13, and a fluid at a specific temperature flows through the ventilation shaft I and the ventilation shaft II; the outer surfaces of the ventilation shaft housing I and the ventilation shaft housing II abut against the inner wall of the outer sleeve roller and rotate therewith.

[0054] Furthermore, the positions where the ventilation shaft housing I and the ventilation shaft housing II contact the inner wall of the outer sleeve roller are downstream of the contact position of the cold air shaft housing.

[0055] The two ventilation shaft assemblies abutting against the outer sleeve roller first play a supporting role. Together with the contact points with the inner shaft, they enable the outer sleeve roller to rotate at a determined spatial position; on the other hand, due to the existence of the two ventilation shafts, they can regulate the temperature of the area about to enter the contact with the billet.

[0056] According to whether reheating is carried out subsequently and whether annealing is required, there are the following situations:

[0057] 1. It is necessary for the billet to dissipate heat as much as possible;

[0058] 2. It is necessary for the billet to dissipate heat naturally;

[0059] 3. It is necessary for the billet to keep warm as much as possible.

[0060] In the first case, a fluid with a lower temperature, such as cold air, industrial water, etc., can be made to flow through the ventilation shaft to cool the outer sleeve roller as much as possible so that its temperature is lower when it contacts the billet subsequently; in this case, heat dissipation also needs to be carried out gradually, so the temperature of the fluid in the ventilation shaft I is higher than the temperature of the fluid in the ventilation shaft II;

[0061] In the second case, air pumped at normal temperature can be made to flow through the ventilation shaft, which is equivalent to air-cooling and dissipating heat from the outer sleeve roller, so that when it contacts the billet, the billet has the same air temperature everywhere, achieving more ideal natural heat dissipation;

[0062] In the third case, high-temperature liquid such as water vapor can be pumped inside the ventilation shaft, so that the temperature of the outer sleeve roller after contact is close to or higher than the surface temperature of the billet, and its residual heat can be preserved as much as possible.

[0063] To effectively implement the above design,

[0064] Furthermore, a partition plate 17 that separates the ventilation shaft I assembly and the ventilation shaft II assembly is provided inside the outer sleeve roller, and a heat-conducting filler 16 is filled in the contact line area between the ventilation shaft I and the ventilation shaft II and the outer sleeve roller; an adiabatic filler 15 is filled between the outer surface of the outer sleeve roller and the cooling bed frame.

[0065] The heat-conducting filler such as a heat-resistant silica gel pad can transfer the temperature of the ventilation shaft to the outer sleeve roller better, while the adiabatic filler can improve the heat flow efficiency inside the device.

[0066] After the cold air shaft shell contacts the surface of the outer sleeve roller, the oxidized slag adhering to it generally breaks off by itself, but there may still be some that remain attached. At this time, if a scraper is used for collection, the friction coefficient of the surface of the outer sleeve roller will still change due to wear and other reasons, and it cannot play the function of improving the safety factor. Therefore,

[0067] Furthermore, on the side wall of the slag receiving hopper, a rake I and a rake II with comb-shaped teeth are arranged along its length direction. The rake I is pulled by an elastic member to abut against the outer surface of the outer sleeve roller, and a ball 21 is arranged at each contact point; the rake II is pulled by an elastic member to abut against the outer surface of the cold air shaft shell, and a ball 21 is arranged at each contact point.

[0068] In such a setting, the elasticity of the elastic member (such as a spring, a rubber band, etc.) can be very small, only ensuring that the rake just touches the outer sleeve roller without scratching it. At the same time, using the ball 21 for contact will better protect the surface of the outer sleeve roller and knock off the residual steel slag skin.

[0069] Furthermore, the slag receiving hopper is arranged obliquely along its length direction, and there is a slag outlet extending out of the cooling bed frame at the lower end.

[0070] Furthermore, the heat-conducting filler is a flexible inorganic non-metallic material with a thermal conductivity higher than that of steel, such as heat-resistant silicone grease, etc.

[0071] Furthermore, the paper thermal material is a flexible inorganic non-metallic material, such as asbestos.

[0072] The heat-conducting filler and the adiabatic filler are filled in the above voids, and can be fixed by a steel wire skeleton to maintain their shapes without moving as the shaft shell rotates.

[0073] The above has described in detail an embodiment of the present invention, but the above content is only a preferred embodiment of the present invention and cannot be considered as defining the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention shall still fall within the scope covered by the patent of the present invention.

Claims

1. Continuous casting cooling bed safety device, which includes a plurality of continuously arranged safety units for bearing the weight of billets, characterized in that: The safety unit includes a cooling bed frame, inner rollers rotatably mounted on the cooling bed frame through inner roller shafts, outer sleeve rollers sleeved on the top surfaces of the inner rollers, and the upper surfaces of the outer sleeve rollers protrude from the cooling bed frame; a cold air hollow shaft is further provided on the cooling bed frame, and cold air flow significantly lower than the surface temperature of the billet flows through it; a cold air shaft housing is rotatably arranged outside the cold air hollow shaft through bearings, and the outer surface of the cold air shaft housing closely adheres to the area where the outer sleeve roller contacts the billet and rotates with the outer sleeve roller under the drive of static friction; a slag receiving hopper is arranged along its contact line below the contact position between the cold air shaft housing and the outer sleeve roller. A hollow ventilation shaft I and ventilation shaft II are further arranged along the axial direction inside the outer sleeve roller, ventilation shaft housings I and II are arranged on the outer peripheries of the ventilation shaft I and ventilation shaft II through bearings, and a fluid at a specific temperature flows through the ventilation shaft I and ventilation shaft II; the outer surfaces of the ventilation shaft housings I and II abut against the inner wall of the outer sleeve roller and rotate therewith. The positions where the ventilation shaft housing I and ventilation shaft housing II contact the inner wall of the outer sleeve roller are downstream of the contact position of the cold air shaft housing. Rake I and rake II with comb-shaped teeth are arranged along the length direction on the side wall of the slag receiving hopper. Rake I is pulled by an elastic member to abut against the outer surface of the outer sleeve roller, and a ball is arranged at each contact point; rake II is pulled by an elastic member to abut against the outer surface of the cold air shaft housing, and a ball is arranged at each contact point.

2. The continuous casting cooling bed safety device according to claim 1, characterized in that: Pushing devices are arranged at both ends of the cold air hollow shaft to adjust the degree of pressing on the outer sleeve roller through the cold air shaft housing.

3. The continuous casting cooling bed safety device according to claim 1, characterized in that: A partition plate separating the ventilation shaft I assembly and the ventilation shaft II assembly is arranged inside the outer sleeve roller, a heat-conducting filler is filled in the contact line area between the ventilation shaft I and ventilation shaft II and the outer sleeve roller; an adiabatic filler is filled between the outer surface of the outer sleeve roller and the cooling bed frame.

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