Device for increasing continuous casting straightening temperature of oversized round billet

Abstract

The utility model relates to a device for improving the continuous casting straightening temperature of an oversized round billet, which is characterized in that a nozzle is arranged in a continuous casting withdrawal and straightening area and is used for heating a casting billet, so that the temperature of the casting billet is not lower than the brittleness temperature of the casting billet. Comprising a fan unit, a natural gas supply system, burner units, a burner control system and a smoke exhaust and heat dissipation device, each burner unit comprises two burners which are symmetrically arranged relative to a casting flow, four withdrawal and straightening machines are respectively provided with the burner units in the withdrawal and straightening direction, and the burner units are arranged in gaps between the front withdrawal and straightening machine and the rear withdrawal and straightening machine; the burner control system is composed of four burner control boxes, each burner control box controls natural gas of each burner of each burner unit to be opened and closed, and an ignition transformer and an ignition controller are arranged in the burner control box and control ignition of each burner respectively. Aiming at round billets with ultra-large specifications and various sizes, the burner units can be adjusted to different heights so as to meet a proper baking angle; and accurate control of the heating temperature is met by adjusting the air volume and the fuel gas.

Description

TECHNICAL FIELD

[0001] The utility model relates to continuous casting device, concretely relates to continuous casting billet heating device when the continuous casting billet is drawn and straightened. BACKGROUND

[0002] On the existing continuous casting machine, the continuous casting billet is mainly straightened by the draw straightener, but as the continuous casting billet enters the straightening area, the temperature continues to drop, the straightening temperature of the large round billet continuous casting is generally reduced by about 100 DEG C from the first draw straightener (about 850 DEG C) to the last straightening draw straightener (about 750 DEG C). When the temperature of the continuous casting billet is less than 800 DEG C, cracks are inevitable for many steel grades, thus resulting in batch quality problems of the continuous casting billet, and the continuous casting billet is even scrapped in batches in serious cases. The multi-point straightening temperature of the continuous casting machine plays a crucial role in the high-quality production of the modern large round billet continuous casting machine. SUMMARY

[0003] The utility model discloses a purpose of setting the burner in the straightening area to heat and warm the continuous casting billet without changing the temperature of the molten steel, the drawing speed and the cooling parameters, thereby improving the straightening temperature of the continuous casting billet, making the straightening temperature of the continuous casting billet not less than the brittle temperature of the continuous casting billet, reducing the cracks caused by straightening, and improving the quality of the continuous casting billet. In addition, the utility model further designs to timely discharge the heat between the upper and lower rollers of the draw straightener and between the front and rear draw straighteners to prevent the damage of the high temperature to the electrical components of the draw straightener, guarantee the stability of the draw straightener, and improve the operation rate of the continuous casting.

[0004] The utility model discloses a purpose of setting the burner in the straightening area to heat and warm the continuous casting billet without changing the temperature of the molten steel, the drawing speed and the cooling parameters, thereby improving the straightening temperature of the continuous casting billet, making the straightening temperature of the continuous casting billet not less than the brittle temperature of the continuous casting billet, reducing the cracks caused by straightening, and improving the quality of the continuous casting billet. In addition, the utility model further designs to timely discharge the heat between the upper and lower rollers of the draw straightener and between the front and rear draw straighteners to prevent the damage of the high temperature to the electrical components of the draw straightener, guarantee the stability of the draw straightener, and improve the operation rate of the continuous casting.

[0005] The fan unit contains a damper regulating proportional valve, and the fan is preferably a fixed-frequency fan, which mainly provides combustion air for each group of burners and adjusts the size of the burner flame by controlling the damper.

[0006] The natural gas supply system provides natural gas for combustion and controls the opening and closing of the natural gas of each burner through the control valves on the connecting pipelines. The control valves include a main pipe shut-off valve, a pressure reducing valve and a pressure relief valve, and are equipped with corresponding pressure sensors. To ensure safety, the main pipe shut-off valve will automatically close in the case of abnormal pressure.

[0007] Burner unit: each burner unit contains two burners arranged symmetrically relative to the casting flow, along the straightening direction, four straightening machines are respectively arranged with the burner unit, and the burner unit is arranged at the interval between the front and rear straightening machines. The burner is made of stainless steel material, the height of the burner can be adjusted according to different casting blank diameters, and the production requirements of three kinds of round blank sections of φ1200mm, φ1000mm and φ800mm can be met; each burner unit is connected with 2 natural gas supply pipelines and combustion air pipelines, in addition, it includes heat insulation protection plate, ignition line and signal feedback line, the heat insulation protection plate of the burner is preferably composed of stainless steel plate and refractory ceramic fiber cotton, which can well insulate heat and resist corrosion, and prolong the service life of the burner. Each burner unit has two burners, the gas control of each burner can be controlled independently, and the baking power of the burner can be adjusted according to the actual casting blank temperature, so as to accurately control the straightening temperature of the casting blank about (850-950 DEG C).

[0008] Burner control system: the burner control system is composed of four burner control boxes for each flow, which are respectively connected with the burners, each burner control box controls the opening and closing of the natural gas of each burner of each group of burner units, each burner control box has two natural gas inlet pipelines and two natural gas outlet pipelines, the burner control box is provided with an ignition transformer and an ignition controller, which respectively control the ignition of each burner; in order to ensure safety, the opening condition of the electromagnetic valve of the burner control box must meet the normal operation of the fan and detect that the pipeline air pressure meets the operation condition; after the condition is met, ignition can be carried out, and if the ignition is unsuccessful, the electromagnetic valve of the natural gas will be immediately closed. The burner body can be adjusted in two ways of angle and axial depth, the burner is installed on the waist hole of the support through the adjusting screw, the installation angle is adjusted through the position of the adjusting screw in the waist hole to realize the heating angle adjustment, and the burner is installed through the U-shaped bolt, and the axial depth is adjusted through the U-shaped bolt.

[0009] Smoke exhaust and heat dissipation device, each group of burners is provided with a smoke exhaust and heat dissipation device on the upper portion, including an irregular collecting cover (conical smoke collecting cover), two counterflow chimneys and a heat insulation protection layer; according to the installation position of the burner and the space size between the straightening machines, according to the large temperature difference between the upper and lower straightening machines, the hot air rising principle is utilized, the smoke, heat and casting blank radiation heat in the combustion process can be quickly discharged, a region with suitable temperature is formed, and the adjacent equipment is prevented from being burnt by high-temperature smoke. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 It is a structure schematic view of the device in the embodiment of the utility model;

[0011] Figure 2 It is a sectional view of the straightening part along the straightening direction in the embodiment of the utility model;

[0012] Figure 3 It is Figure 2A cross-sectional view of the middle CC;

[0013] Figure 4 A structure diagram of the burner in the embodiment of the utility model;

[0014] Figure 5 A structure diagram of the burner in the embodiment of the utility model; Figure 4 A view of A direction of the structure shown in the figure;

[0015] Figure 6 A view of B direction of the structure shown in the figure; Figure 4 A view of B direction of the structure shown in the figure;

[0016] Figure 7 A perspective view of the burner shown in the figure; Figure 4 A perspective view of the burner shown in the figure;

[0017] Figure 8 A perspective view of the burner shown in the figure; Figure 4 A perspective view of the burner shown in the figure;

[0018] Figure 9 A perspective view of the burner shown in the figure;

[0019] Figure 10 A perspective view of the burner shown in the figure;

[0020] In the figure, fan unit 1, natural gas supply system 2, burner unit 3, burner control system 4, smoke exhaust device 5, damper regulating proportional valve 6, straightener 7, 301 burner body, 302 natural gas pipeline, 303 air pipeline, 304 air hose connection, 305 natural gas hose connection, 306 stroke adjustment point, 307 adjusting screw, 308 U-shaped bolt. DETAILED DESCRIPTION

[0021] The utility model will be further described in detail below in combination with the drawings, the embodiment is exemplary, aims at explaining the utility model, and can not be understood as the limitation of the utility model.

[0022] The application relates to a novel method and device for improving the straightening temperature of an ultra-large-specification round billet continuous casting machine, which comprises a fan unit, a natural gas supply system, a burner unit, a burner control system and a smoke exhaust device. The fan unit comprises a damper regulating proportional valve in each group, and the fan is a fixed-frequency fan. The main function of the fan unit is to provide combustion air for each group of burners, and the size of the burner flame is adjusted by controlling the damper. The main function of the natural gas supply system is to provide natural gas for combustion, and the opening and closing of natural gas in each group are controlled by a cut-off valve. The control valve comprises a main pipe cut-off valve, a pressure reducing valve and a pressure relief valve, and corresponding pressure sensors are arranged. In the case of abnormal pressure, the main pipe cut-off valve is automatically closed to ensure safety. Each burner unit comprises two burners arranged above and below, and each flow is divided into 1-4 drawing straightening machines, totaling 8 burner units. The burners can be made of stainless steel, and the height of the burner unit can be adjusted according to different diameters of the cast billet to meet the production requirements of various sections of the ultra-large-specification round billet. Each burner unit is connected with two natural gas supply pipelines and combustion air pipelines, and additionally comprises a heat insulation protective plate, an ignition line and a signal feedback line. The burner control system is composed of four burner control boxes for each flow. Each burner control box controls the opening and closing of natural gas for each group of four burners. Each burner control box has two natural gas inlet pipelines and four natural gas outlet pipelines. The burner control box is provided with an ignition transformer and an ignition controller for controlling the ignition of each group of burners. To ensure safety, the opening condition of the electromagnetic valve of the burner control box must meet the normal operation of the fan and the detection of the pipeline air pressure meeting the operation condition. After the conditions are met, ignition can be performed. If the ignition is unsuccessful, the electromagnetic valve of the natural gas control system will be immediately closed. Each group of burners is provided with a smoke exhaust device on the upper portion, which comprises an irregular collecting cover, two counterflow chimneys and a heat insulation protective layer. According to the installation position of the burners and the space size between the drawing straightening machines, the hot air rising principle is utilized to quickly exhaust the smoke, heat and radiation heat of the cast billet during the combustion process, form a region with a suitable temperature, and prevent the adjacent equipment from being damaged by high-temperature smoke. For the ultra-large-specification round billet, the height of the burner unit can be adjusted to meet the appropriate baking angle. According to the adjustment of the air volume and the size of the gas, the heating temperature can be accurately controlled. The application of the method and device for improving the straightening temperature of the continuous casting machine can improve and maintain the straightening point temperature of the large-specification round billet, and reduce the crack risk caused by the low-temperature straightening of the cast billet.

[0023] The above method and device are suitable for the continuous casting process of an ultra-large-specification round billet with a diameter of more than 800 mm.

[0024] One fan unit controls four burners units by four pipes, each pipe uses a regulating valve to control the air volume, according to the slab temperature to adjust the opening of the valve, and natural gas to adjust at the same time, control the intensity of the burner flame, to meet the requirements of the slab baking temperature. After the adjustment of the total pipe regulating valve and pressure reducing valve, the natural gas with appropriate pressure is delivered to each burner control system, which works synchronously with the fan unit pressure. When the fan pipe pressure is abnormal, the cut-off valve in the natural gas supply system will be closed immediately.

[0025] The burner unit is located at the straightening point of the straightening machine, and the burner directly bakes the slab. The straightening temperature of the slab will not change due to the change of the straightening position of the continuous casting slab. The straightening point slab temperature can be maintained at about 850-950℃. Each burner unit has two burners, and the gas control of each burner can be controlled individually. The baking power of the burner can be adjusted according to the actual slab temperature to accurately control the straightening temperature of the slab.

[0026] The baking angle and height of each burner unit can be adjusted at any time according to the change of the slab size to ensure that the baking position is at the stress concentration position.

[0027] The protection and heat insulation device of the burner uses a combination of stainless steel plate and refractory ceramic fiber cotton, which can provide good heat insulation and corrosion resistance, and prolong the service life of the burner. The protection and heat insulation device of the burner adopts a special design and is installed in the gap position before and after the straightening machine, which can eliminate the gap between the straightening machines and prevent cold air from entering and affecting the surface of the slab. At the same time, it also plays the role of a slab heat preservation cover.

[0028] The burner control system is composed of four burner control boxes for each flow. Each burner control box controls four burners. Each control contains a flow regulating valve, an electromagnetic valve, an ignition transformer and an ignition controller, which respectively control the ignition, shutdown and flame size of each group of burners. The size of the natural gas can be adjusted according to the change of the slab temperature, or several burners can be used for baking.

[0029] An irregular collecting cover is arranged in the upper space of the burner, and two counterflow chimneys with a height of about 2 meters. According to the installation position of the burner and the space size between the straightening machines, the temperature difference between the upper and lower straightening machines is large, and the hot air rising principle is used to quickly discharge the flue gas, heat and radiation heat of the slab during the combustion process. The heat dissipation device can be made of galvanized steel plate or stainless steel plate, and a layer of heat-resistant cotton is fixed inside to reduce the influence of heat radiation on its deformation and improve its service life. In order to better collect high-temperature flue gas, the shape is a horn mouth. In order to ensure the sealing performance, the size is made according to the installation gap size between the front and rear straightening machines, and the error cannot be greater than 3mm.

[0030] Example 1: A new method and device for improving the straightening temperature of ultra-large round billet continuous casting. As shown in Figure 1As shown, including fan unit, natural gas supply system, burner unit using 4 groups, height adjustment for 800, burner control system, exhaust heat dissipation device.

[0031] Casting blank 1 type with 0.2m / min pulling speed for straightening, temperature measurement before entering the straightening machine is about 840℃, fan unit damper is adjusted to 40%, air flow is about 60Nm 3 / h; natural gas pressure is adjusted to 1.5bar; 1 flow 4 group burner unit height is all adjusted to 800 position; burner control box adjusts natural gas pressure to 1.5KPa, burner control 4 group burner unit all ignition baking, exhaust heat dissipation device normal operation, measurement of casting blank entering straightening point temperature is about 855 degrees; meet the process requirements. In the case of constant pulling speed, no need to adjust the above control system, can work continuously to the end of production.

[0032] Example 2: A new method and device for improving the straightening temperature of ultra-large specification round billet continuous casting. As shown, Figure 1 including fan unit, natural gas supply system, burner unit using 2 groups, height adjustment for 800, burner control system, exhaust heat dissipation device.

[0033] Casting blank 1 type with 0.22m / min pulling speed for straightening, temperature measurement before entering the straightening machine is 860℃, fan unit damper is adjusted to 30%, air flow is about 45Nm 3 / h; natural gas pressure is adjusted to 1.0bar; 1 flow 4 group burner unit height is all adjusted to 800 position; burner control box adjusts natural gas pressure to 1.0KPa, burner control box controls 2 group burner unit ignition baking after straightening machine, exhaust heat dissipation device normal operation, measurement of casting blank entering straightening point temperature is about 855 degrees; meet the process requirements. The same as example 1.

[0034] Example 3: A new method and device for improving the straightening temperature of ultra-large specification round billet continuous casting. As shown, Figure 1 including fan unit, natural gas supply system, burner unit using 2 groups, height adjustment for 1000, burner control system, exhaust heat dissipation device.

[0035] Casting blank 2 type with 0.15m / min pulling speed for straightening, temperature measurement before entering the straightening machine is 870℃, fan unit damper is adjusted to 20%, air flow is about 30Nm 3 / h; natural gas pressure is adjusted to 1bar; 1 flow 4 group burner unit height is all adjusted to 1000 position; burner control box adjusts natural gas pressure to 1.0KPa, burner control box controls 2 group burner unit ignition baking after straightening machine, exhaust heat dissipation device normal operation, measurement of casting blank entering straightening point temperature is about 860 degrees; meet the process requirements. The same as example 1.

[0036] Example 4: A new method and device for improving the straightening temperature of ultra-large round billets. As shown in Figure 1 , including fan unit, natural gas supply system, burner unit using 4 groups, height adjustment to 1000, burner control system, exhaust smoke heat dissipation device.

[0037] Casting billet 2 type at 0.13 m / min drawing speed, temperature before entering the straightening machine is 830℃, fan unit damper is adjusted to 60%, air flow is about 90 Nm 3 / h; natural gas pressure is adjusted to 2 bar; 1 flow 4 group burner unit height is all adjusted to 1000 position; burner control box adjusts natural gas pressure to 2.0 KPa, burner control box controls 4 group burner unit ignition baking, exhaust smoke heat dissipation device is normally running, the measured casting billet entering straightening point temperature is about 855 degrees; meet the process requirements. The rest is the same as example 1.

[0038] Example 5: A new method and device for improving the straightening temperature of ultra-large round billets. As shown in Figure 1 , including fan unit, natural gas supply system, burner unit using 2 groups, height adjustment to 1200, burner control system, exhaust smoke heat dissipation device.

[0039] Casting billet 3 type at 0.12 m / min drawing speed, temperature before entering the straightening machine is 860℃, fan unit damper is adjusted to 40%, air flow is about 60 Nm 3 / h; natural gas pressure is adjusted to 1.5 bar; 1 flow 4 group burner unit height is all adjusted to 1200 position; burner control box adjusts natural gas pressure to 1.5 KPa, burner control box controls 2 group burner unit ignition baking after the straightening machine, exhaust smoke heat dissipation device is normally running, the measured casting billet entering straightening point temperature is about 850 degrees; meet the process requirements. The rest is the same as example 1.

Claims

1. A device for increasing the straightening temperature of ultra-large diameter round billets in continuous casting, characterized in that: The fan unit, the natural gas supply system, the burner unit, the burner control system, the smoke exhaust device, The fan unit provides combustion air for each burner of the burner unit, and sets a damper adjustment proportional valve to control the damper to adjust the size of the burner flame. The natural gas supply system provides natural gas for combustion for each burner of the burner unit, and controls the opening and closing of the natural gas of each burner through a control valve on the connecting pipeline, the control valve includes a main pipe cut-off valve, a pressure reducing valve and a pressure relief valve, and corresponding pressure sensors are arranged, and the main pipe cut-off valve will automatically close in the case of pressure abnormality. The burner unit: each burner unit includes two burners arranged symmetrically relative to the casting flow, and four drawing straightening machines are respectively arranged with the burner unit along the drawing straightening direction, and the burner unit is arranged at the interval between the front and rear drawing straightening machines. The burner control system: composed of four burner control boxes, each burner control box controls the opening and closing of the natural gas of each burner of each burner unit, each burner control box is provided with a natural gas inlet pipeline and a natural gas outlet pipeline, which are respectively connected with each burner, the burner control box is provided with an ignition transformer and an ignition controller, which respectively control the ignition of each burner; the opening condition of the electromagnetic valve of the burner control box meets the normal operation of the fan, and the ignition is started after the pipeline air pressure meets the operation condition, and the electromagnetic valve of the natural gas will be immediately closed in the case of unsuccessful ignition. The smoke exhaust device: arranged on the upper part of each burner, including a collecting cover, two convection chimneys and a heat insulation protective layer, according to the installation position of the burner and the space size between the drawing straightening machines, the hot air rising principle is used to exhaust the smoke, heat and heat radiation of the casting blank according to the large temperature difference between the upper and lower drawing straightening machines.

2. The apparatus of claim 1, wherein: The burner control box controls the burner unit to work independently through local or HMI.

3. The apparatus of claim 1, wherein: The burner is made of stainless steel, and the heating height and angle of the burner can be adjusted.

4. The apparatus of claim 3, wherein: The burner body can be adjusted in two ways of angle adjustment and axial depth adjustment, the burner is installed on the waist hole of the support through the adjusting screw, the installation angle is adjusted by adjusting the position of the adjusting screw in the waist hole to realize the heating angle adjustment, the burner is installed through the U-shaped bolt, and the axial depth is adjusted by adjusting the U-shaped bolt.

5. The apparatus of claim 1, wherein: The heat insulation protective layer of the burner is combined with stainless steel plate and refractory ceramic fiber cotton, and is designed in a special shape suitable for the gap between the front and rear drawing straightening machines, and is installed in the gap position between the front and rear drawing straightening machines to eliminate the gap between the drawing straightening machines and serve as a heat preservation cover for the casting blank.

6. The apparatus of claim 1, wherein: The collecting cover is a horn mouth, and the size is suitable for the installation gap size of the front and rear drawing straightening machines.

Images