Novel continuous casting conical nozzle test device and test method

Abstract

The invention relates to the technical field of steelmaking production, in particular to a novel continuous casting conical nozzle test device and test method.The novel continuous casting conical nozzle test device comprises a water tank and a pipeline, the water inlet end of the pipeline is connected with the water tank, and the water outlet end of the pipeline is connected with a nozzle; the control mechanism is mounted on the pipeline and used for controlling the water pressure; and the test mechanism is arranged at the water outlet end of the nozzle and is used for performing a nozzle test experiment. According to the novel conical nozzle test device for continuous casting, the problems that in the using process, due to the situation that a traditional nozzle sprays a water column or drips water due to the service time problem, the water column or the water drop falls on a casting blank for a long time, and consequently cooling of the casting blank is uneven, the casting blank is bent, and the internal structure is inconsistent are solved; meanwhile, an adjusting device is additionally arranged in the nozzle to reduce nozzle blockage, the conical and rectangular use of the novel nozzle reduces nozzle replacement, the casting blank quality is effectively improved, and the practicability is high.

Description

Technical Field

[0001] The present invention relates to the technical field of steelmaking production, and in particular to a novel conical nozzle test device and test method for continuous casting. Background Art

[0002] In the process of steelmaking production, in the process of molten steel forming, continuous casting process is often used to treat molten steel to form billets. Continuous casting of steel is a process of continuously casting molten steel into billets by a continuous caster. Compared with ingot casting, continuous casting has the characteristics of energy saving, high efficiency and high metal yield. The qualified molten steel is transported to the turntable by a ladle. After the turntable rotates to the pouring position, the molten steel is injected into the tundish. The tundish distributes the molten steel to each mold through a nozzle. The mold makes the molten steel quickly form crystals. Under the combined action of the straightening machine and the vibration table, the billet is pulled out of the mold. After secondary cooling and straightening, it is cut into billets of a certain length. The billets are transported to the rolling mill by using a cooling bed, a turntable and a conveying roller table.

[0003] In the process of continuous casting billet production, continuous casting nozzles are usually used to cool the billets. The continuous casting nozzles are mainly composed of gas, water pressure, flow rate and temperature sensors. Through computer real-time acquisition and processing, the pressure and flow rate values of each point are detected and converted into flow characteristic curves. A special liquid collection and transmission device and several liquid sensors are used to collect and process the liquid level values of the water volume distribution points and the spraying angles of the nozzles through preliminary laboratory simulation, and continuous casting nozzles suitable for use are made.

[0004] When using water nozzles on a continuous caster, the surface of the billet is cooled by spraying water to reduce its surface temperature, and at the same time, the heat inside the billet is transferred out, which helps to make the internal structure of the billet uniform. Therefore, the heat transfer between the cooling water and the surface of the billet is very important. During continuous casting operation, uneven water spraying occurs during the water spraying cooling process on the surface of the billet. Too much water is sprayed at some positions, and no spraying is carried out at some positions. Traditional nozzles cannot adjust the water spraying pressure and atomization treatment, and are prone to nozzle blockage due to water quality and particulate matter during use. Therefore, a novel conical nozzle test device for continuous casting is needed to solve the above problems. Summary of the Invention

[0005] The purpose of the embodiments of the present invention is to provide a novel conical nozzle test device and test method for continuous casting, aiming to solve the problems mentioned in the background art.

[0006] The embodiments of the present invention are implemented as follows. A novel conical nozzle test device and test method for continuous casting includes: a water tank and a pipeline. The water inlet end of the pipeline is connected to the water tank, and the water outlet end of the pipeline is connected to a nozzle; a control mechanism installed on the pipeline for controlling the water pressure; and a test mechanism arranged at the water outlet end of the nozzle for conducting nozzle test experiments.

[0007] Preferably, the control mechanism includes: a first valve installed on the pipeline, a second valve is arranged on one side of the first valve, and the first valve and the second valve are used to control the spray water pressure of the nozzle; a water pressure gauge installed on the pipeline for displaying the magnitude of the spray water pressure, and a flow meter installed on the pipeline is arranged on one side of the water pressure gauge.

[0008] Preferably, the testing mechanism includes: a water tank arranged directly below the nozzle, and a drain pipe connected to the lower side of the water tank for discharging the water therein; test tubes arranged in the water tank, and a plurality of test tubes are arranged and evenly distributed for collecting the water sprayed from the nozzle to conduct a nozzle test experiment.

[0009] A new type of conical nozzle test method for continuous casting includes the following steps: Step 1: Install the nozzle to be tested at the water outlet end of the pipeline, and adjust the spray height of the nozzle to be consistent with the actual spray height in continuous casting production. The nozzle is perpendicular to the test tube and cannot be skewed; Step 2: Open the first valve and the second valve in sequence, and adjust the first valve and the second valve to make the value in the water pressure gauge reach the target values of 0.2 MPa and 0.1 MPa; Step 3: After the nozzle sprays water for a period of time, close the first valve and the second valve, and record the water volume in the test tubes at different positions through a camera. It should be noted that the water in the test tube cannot exceed the volume of the test tube, otherwise the experiment needs to be repeated.

[0010] The new type of conical nozzle test device provided by the present invention avoids the situation that traditional nozzles spray water columns or drip water due to the use time during use, resulting in uneven cooling of the slab, slab bending, and inconsistent internal structure caused by the water column or water droplets falling on the slab for a long time. At the same time, an adjustment device is added inside the nozzle to reduce nozzle blockage. The use of the conical and rectangular nozzles reduces the replacement of the nozzles, effectively improves the quality of the slab, and has strong practicability. Description of the Drawings

[0011] Figure 1 It is a schematic diagram of a new type of conical nozzle test device for continuous casting.

[0012] Figure 1.1 It is a schematic diagram of the water flow distribution of the conical nozzle.

[0013] Figure 1.2 It is the water flow distribution of the rectangular nozzle.

[0014] In the drawings: 1 - water tank, 2 - pipeline, 3 - nozzle, 4 - control mechanism, 5 - testing mechanism, 41 - first valve, 42 - second valve, 43 - water pressure gauge, 44 - flow meter, 51 - water tank, 52 - drain pipe, 53 - test tube. Detailed Embodiments

[0015] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not limit the present invention.

[0016] The following describes in detail the specific implementation of the present invention with reference to specific embodiments.

[0017] Please refer to Figure 1 , a novel conical nozzle test device and test method for continuous casting provided by an embodiment of the present invention, the novel conical nozzle test device and test method for continuous casting include: A water tank 1 and a pipeline 2, the water inlet end of the pipeline 2 is connected to the water tank 1, and the water outlet end of the pipeline 2 is connected to a nozzle 3; a control mechanism 4, which is installed on the pipeline 2 and is used to control the water pressure; a test mechanism 5, which is arranged at the water outlet end of the nozzle 3 and is used to conduct a nozzle test.

[0018] As Figure 1 shown, as a preferred embodiment of the present invention, the control mechanism 4 includes: a first valve 41, which is installed on the pipeline 2, a second valve 42 is arranged on one side of the first valve 41, and the first valve 41 and the second valve 42 are used to control the spraying water pressure of the nozzle 3; a water pressure gauge 43, which is installed on the pipeline 2 and is used to display the magnitude of the spraying water pressure, and a flow meter 44 installed on the pipeline 2 is arranged on one side of the water pressure gauge 43.

[0019] As Figure 1 shown, as a preferred embodiment of the present invention, the test mechanism 5 includes: a water tank 51, which is arranged directly below the nozzle 3, a drain pipe 52 for discharging the water inside is connected to the lower side of the water tank 51; test tubes 53, which are arranged in the water tank 51, and there are multiple test tubes 53 and they are evenly distributed, and are used to collect the water sprayed from the nozzle 3 for conducting a nozzle test.

[0020] The present invention tests the working principle of the nozzle during the continuous casting slab production process. The nozzle test platform is divided into three parts: a water supply part, a control mechanism 4 and a test mechanism 5. The water supply part is composed of a water tank 1, a pipeline 2 and a nozzle 3. The control mechanism 4 is composed of a flow meter 44, a first valve 41, a second valve 42 and a water pressure gauge 43. The test mechanism 5 is composed of test tubes 53, a water tank 51 and a drain pipe 52.

[0021] A test method for a new type of conical nozzle used in continuous casting, comprising the following steps: Step 1: Install the nozzle 3 to be tested at the water outlet end of the pipeline 2, and adjust the spraying height of the nozzle 3 to make it conform to the actual spraying height in continuous casting production. The nozzle 3 is perpendicular to the test tube 53 and cannot be skewed; Step 2: Open the first valve 41 and the second valve 42 in sequence, and adjust the first valve 41 and the second valve 42 to make the value in the water pressure gauge 43 reach the target values of 0.2 MPa and 0.1 MPa; Step 3: After the nozzle 3 sprays for a period of time, close the first valve 41 and the second valve 42, and record the water volume in the test tubes 53 at different positions through a camera. It should be noted that the water in the test tube 53 cannot exceed the volume of the test tube 53, otherwise the experiment needs to be carried out again.

[0022] The method of the nozzle test experiment is as follows: Install the nozzle 3 to be tested, and adjust the spraying height of the nozzle 3 to make it conform to the actual spraying height in continuous casting production. The nozzle 3 is perpendicular to the water collection device and cannot be skewed. Open the first valve 41 and the second valve 42 in sequence, and adjust the first valve 41 and the second valve 42 to make the value in the water pressure gauge reach the target values of 0.2 MPa and 0.1 MPa. By simulating the transformation of the original common nozzle 3, the conventional round-head nozzle 3 is changed to a conical nozzle 3 and a rectangular nozzle 3. By optimizing the shape, the flow trajectory of the cooling water inside the nozzle 3 is changed, so that the cooling water forms a refraction after hitting the inner wall and changes the original movement trajectory. For the internal flow field of the nozzle 3, the full-roll section, the first secondary cooling section, and the second secondary cooling section in the secondary cooling area are changed to conical nozzles 3. The impact pressure of the water column on the inner wall of the conical nozzle 3 is greater than that of the round nozzle 3, which better promotes the flow of the cooling water inside the nozzle and reduces the probability of scaling inside the nozzle 3; at the same time, changing to a conical nozzle 3 increases the pressure inside and at the end of the nozzle 3, which is conducive to the formation of water spray atomization and then improves the water spray effect, increases the contact area with the billet, and has a better atomization effect compared with the traditional conical nozzle 3, avoiding the situation that the traditional nozzle 3 is blocked and the water spray is uneven, forming a water column or dripping water due to the use time and water quality problems during use; changing the third secondary cooling section and the fourth secondary cooling section to rectangular nozzles 3 increases the flow rate and pressure. The above situations will lead to problems such as uneven cooling of the billet, bending of the billet, inconsistent internal structure, and bending of the steel billet due to uneven spraying during continuous casting production. At the same time, an adjustable filter device is added inside the nozzle 3 to reduce nozzle blockage, reduce nozzle replacement, and effectively improve the quality of the billet.

[0023] The nozzle test experiment data is as follows:

[0024] Spraying characteristics of the secondary cooling conical nozzle: The percentage of water flow at different positions can be determined by the amount of water in the test tube 53. Experiments are conducted on the conical nozzles 3 in the foot roll section, the first secondary cooling section, and the second secondary cooling section respectively, and the amount of water in the test tube 53 is counted. The percentage of the water flow distribution of different conical nozzles 3 is as Figure 1.1 (b) - (d) shown. From Figure 1.1 (b) - (d), it can be seen that the increase in pressure has little effect on the water flow distribution of the conical nozzle 3.

[0025] Figure 1.1 (b) is the water flow distribution of the nozzle 3 in the foot roll section. It can be seen from the figure that the proportion of the water flow in the center of the nozzle 3 is relatively high, about 14.5%. As the distance from the center of the nozzle 3 increases, the proportion of the water flow gradually decreases. Figure 1.1 (c) is the water flow distribution of the nozzle 3 in the first secondary cooling section. It can be seen from the figure that the proportion of the water flow in the center of the nozzle 3 is relatively low, and the proportion of the water flow on both sides is relatively high. The peak value of the water flow of the nozzle 3 in the first secondary cooling section appears at the position 84 mm away from the center of the nozzle 3, and the proportion is between 7.5% and 9%. Figure 1.1 (d) is the water flow distribution curve of the nozzle 3 in the second secondary cooling section. From Figure 1.1 (d), it can be seen that the water flow distribution curve of the nozzle 3 in the second secondary cooling section has three peak values, and the water flow distribution is more uniform.

[0026] Figure 1.1 Among them: (a) is the water collection in the test tube; (b) is the foot roll section; (c) is the first secondary cooling section; (d) is the second secondary cooling section.

[0027] Spraying characteristics of the rectangular nozzle in the secondary cooling: The water flow distribution of the rectangular nozzle 3 under different pressures is as Figure 1.2 shown. Figure 1.2 (a) - (b) are the longitudinal and transverse water flow distribution curves of the rectangular nozzle 3 in the third secondary cooling section respectively. From Figure 1.2 (a) - (b), it can be seen that the increase in pressure has little effect on the water flow distribution of the nozzle 3 in the third secondary cooling section. From Figure 1.2 (a), it can be known that the longitudinal water flow distribution of the rectangular nozzle 3 in the third secondary cooling section is relatively uniform. The highest proportion of the water flow is 3.75%, and the lowest proportion is 2.62%. The difference between the two is only 1.13%. Figure 1.2 (b) is the transverse water flow distribution of the rectangular nozzle 3 in the third secondary cooling section. The proportion of the water flow at the center position of the nozzle 3 is the highest, between 8% and 9.12%. Horizontally, as the distance from the center of the nozzle 3 in the third section increases, the proportion of the water flow gradually decreases.

[0028] Figure 1.2 Among them: (a) is the longitudinal direction of the nozzle in the third secondary cooling section; (b) is the transverse direction of the nozzle in the third secondary cooling section; (c) is the longitudinal direction of the nozzle in the fourth secondary cooling section; (d) is the transverse direction of the nozzle in the fourth secondary cooling section.

[0029] The longitudinal distribution curve of the water flow rate of the rectangular nozzle 3 in the fourth secondary cooling section is as Figure 1.2 (c) shown. As can be seen from Figure 1.2 (c), when the water pressure increases, the uniformity of the longitudinal distribution of the water flow rate of the rectangular nozzle 3 increases. When the pressure is 0.1 MPa, the difference between the highest point and the lowest point in the longitudinal direction of the rectangular nozzle 3 in the fourth secondary cooling section is 2.1%. When the pressure is 0.2 MPa, the difference between the highest point and the lowest point in the longitudinal direction of the rectangular nozzle 3 in the fourth secondary cooling section is 1.75%. The transverse distribution curve of the water flow rate of the rectangular nozzle 3 in the fourth secondary cooling section is as Figure 1.2 (d) shown. As can be seen from Figure 1.2 (d), when the pressure is 0.1 MPa, the proportion of the water flow rate at the center of the nozzle 3 is the highest, which is 9.2%. As the distance from the center of the nozzle 3 increases, the proportion of the water flow rate gradually decreases. When the pressure increases to 0.2 MPa, the proportion of the water flow rate at the center of the nozzle 3 decreases, and the peak appears on both sides of the center of the nozzle 3, and the proportion of the water flow rate is 8%.

[0030] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A new type of conical nozzle test device for continuous casting, including a water tank and a pipeline, characterized in that: The water inlet end of the pipe is connected to the water tank, and the water outlet end of the pipe is connected to a nozzle; A control mechanism, which is installed on the pipeline and is used to control the water pressure; The testing mechanism is arranged at the water outlet end of the nozzle and is used for performing nozzle testing experiments.

2. The novel tapered nozzle test device for continuous casting according to claim 1 is characterized in that: The control mechanism comprises: A first valve is installed on the pipeline, a second valve is provided on one side of the first valve, and the first valve and the second valve are used to control the spraying water pressure of the nozzle; A water pressure gauge is installed on the pipeline and is used to display the size of the spray water pressure. A flow meter installed on the pipeline is provided on one side of the water pressure gauge.

3. The novel tapered nozzle test device for continuous casting according to claim 1 is characterized in that: The testing organization includes: A water tank is arranged directly below the nozzle, and a drain pipe for draining the water therein is connected to the lower side of the water tank; The test tube is arranged in the water tank. There are multiple test tubes evenly distributed, and they are used to collect water sprayed from the nozzles to conduct nozzle testing.

4. A new type of continuous casting conical nozzle test device and test method, characterized in that: The invention comprises the novel tapered nozzle test device for continuous casting as described in claims 1 to 3 and the following steps: Step 1: Install the nozzle to be tested at the outlet of the pipe, and adjust the spray height of the nozzle to match the actual spray height in continuous casting production. The nozzle should be perpendicular to the test tube and cannot be skewed; Step 2: Open the first valve and the second valve in sequence, and adjust the first valve and the second valve to make the values ​​in the water pressure gauge reach the target values ​​of 0.2MPa and 0.1MPa; Step 3: After the nozzle sprays for a period of time, close the first valve and the second valve, and use the camera to record the amount of water in the test tube at different positions. It should be noted that the water in the test tube cannot exceed the volume of the test tube, otherwise the experiment should be repeated.

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