Laminar cooling system with controllable water temperature

Abstract

The utility model discloses a laminar cooling system with controllable water temperature. The laminar cooling system comprises a laminar cooling assembly and a circulating pipeline, the laminar cooling assemblies are connected in parallel, and cooled water sequentially flows to the radiator and the first water tank through the circulating pipeline and then is pumped into the cooling assemblies connected in parallel through the first water pump to be recycled. A first valve is arranged between the first water pump and the laminar cooling assembly; an auxiliary pipeline is connected to the circulating pipeline between the first valve and the laminar cooling assembly, and a cold water tank, a second water pump and a second valve are sequentially connected to the auxiliary pipeline; and a first temperature sensor is arranged between the laminar cooling assembly at the tail end of the output roller way and the pinch roll. The device has the advantages of being controllable in temperature, accurate in cooling and stable in output.

Description

Technical Field

[0001] The utility model relates to the technical field of rolling steel cooling, in particular to a laminar flow cooling system with controllable water temperature. Background Art

[0002] The post-rolling cooling of strip steel is an important link in the controlled rolling and controlled cooling process, and its cooling rate directly affects the microstructure and properties of steel. The post-rolling cooling generally adopts the laminar flow cooling method. Laminar flow cooling refers to an on-line controlled cooling process for hot-rolled steel plates or strip steel using laminar water flow. Several laminar flow headers are installed above the output roller table of the finishing mill, and the smooth and coherent water flow falls from above to the surface of the fast-moving strip steel to cool it.

[0003] The cooling after hot rolling not only reduces the temperature of the strip steel, but more importantly, the transformation of austenite microstructure basically occurs during this process. By controlling the cooling rate and coiling temperature after hot rolling, the required microstructure and grain size can be obtained. In actual production, the product consistency deviation of strip steel often occurs. The main reasons are as follows: First, the temperature of the strip steel rolled out from the rolling mill fluctuates within a certain range and is not a fixed value. The existing laminar flow cooling is a cooling system with fixed parameters designed based on a certain fixed initial temperature of the strip steel. Therefore, for strip steel with different initial temperatures, the microstructure and properties of the steel will be affected. Second, the cooling water system uses a cooling tower to cool the circulating water, and the temperature of the cooled water also fluctuates within a certain range. The water temperature regulation is not accurate enough, which will also affect the cooling effect and thus the quality of the strip steel. Summary of the Utility Model

[0004] The utility model is used to overcome the defects of the existing technology and provides a laminar flow cooling device with controllable water temperature to solve the problems mentioned in the background art.

[0005] To achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A laminar flow cooling system with controllable water temperature includes: a laminar flow cooling component and a circulating pipeline; a plurality of the laminar flow cooling components are connected in parallel, and the water after cooling flows through the circulating pipeline to the cooling tower and the first water tank in sequence, and then is pumped into the parallel cooling components for recycling by the first water pump; a first valve is arranged between the first water pump and the laminar flow cooling component; an auxiliary pipeline is connected to the circulating pipeline between the first valve and the laminar flow cooling component, and a cold water tank, a second water pump, and a second valve are sequentially connected to the auxiliary pipeline; a first temperature sensor is arranged between the laminar flow cooling component at the end of the output roller table and the pinch roll.

[0007] For the above laminar cooling system with controllable water temperature, a water temperature sensor is provided on the circulation pipeline. The water temperature sensor is arranged after the access point of the auxiliary pipeline and the circulation pipeline and before the laminar cooling component to monitor the water temperature entering the laminar cooling component.

[0008] For the above laminar cooling system with controllable water temperature, a second temperature sensor is added between the four-high rolling mill and the laminar cooling component to monitor the initial temperature of the strip when it is rolled out from the four-high rolling mill.

[0009] For the above laminar cooling system with controllable water temperature, a CPU and a control circuit are added. The signal outputs of the water temperature sensor, the first temperature sensor, and the second temperature sensor are connected to the input end of the CPU. The output end of the CPU is respectively connected to the control relay through a triode amplifier circuit, and the relay is respectively connected to control the first water pump, the second water pump, the first valve, and the second valve.

[0010] For the above laminar cooling system with controllable water temperature, the laminar cooling component is composed of a bracket and a laminar rack. A water curtain header is arranged on the laminar rack; a slide rail is arranged on the bracket, and a slider matching the slide rail is arranged on the laminar rack, and the height of the laminar rack on the bracket is adjustable.

[0011] For the above laminar cooling system with controllable water temperature, the number of laminar cooling components is 25 - 29 groups, which are arranged along the output roller table. Beneficial effects

[0012] Compared with the prior art, the utility model has the following advantages: First, by accessing the auxiliary pipeline, a first temperature sensor is arranged between the laminar cooling component at the end of the output roller table and the pinch roll. The cold water addition amount is adjusted according to the temperature of the strip after cooling, the temperature of the steel after cooling is stabilized, and it fluctuates within a small range above and below the optimal cooling temperature, which is beneficial to ensuring the product quality and the consistency of the product. Second, by measuring the initial temperature fluctuation of the strip after rolling through the second temperature sensor, the opening degrees of the first water pump, the second water pump, the first valve, and the second valve are actively controlled to control the water temperature. The first temperature sensor and the second temperature sensor cooperate to more accurately control the cooling of the strip. Third, a CPU and a control circuit are set to monitor the initial temperature, the temperature after cooling, and the water temperature of the cooling water of the strip in real time, so as to accurately control the water temperature of the cooling water entering the laminar cooling system, thereby ensuring the product quality of the strip. Description of the drawings

[0013] The following further details the utility model in conjunction with the drawings.

[0014] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0015] Figure 2 It is a schematic diagram of the water circuit circulation of the utility model;

[0016] Figure 3 It is a schematic diagram of the monitoring and control of the present utility model;

[0017] Each label in the figure represents respectively:

[0018] 1. laminar cooling assembly, 2. circulation pipeline, 3. radiator, 4. first water tank, 5. first water pump, 6. first valve, 7. auxiliary pipeline, 8. cold water tank, 9. second water pump, 10. second valve, 11. pinch roll, 12. first temperature sensor, 13. water temperature sensor, 14. four-high rolling mill, 15. second temperature sensor, 16. strip steel, 17. output roller table, 1-1. bracket, 1-2. laminar rack, 1-3. slide rail, J1-J4. first relay - fourth relay, T1-T4. first triode - fourth triode. Specific implementation mode

[0019] The present utility model will be further described in detail below in conjunction with the drawings and embodiments.

[0020] As Figures 1 - 3 shown, the present utility model includes: laminar cooling assembly 1, circulation pipeline 2; a plurality of the laminar cooling assemblies 1 are connected in parallel, and the cooled water flows through the circulation pipeline 2 to the cooling tower 3 and the first water tank 4 in sequence, and then is pumped into the parallel cooling assemblies 1 by the first water pump 5 for recycling. The number of the laminar cooling assemblies 1 is 25 - 29 groups.

[0021] A first valve 6 is arranged between the first water pump 5 and the laminar cooling assembly 1; an auxiliary pipeline 7 is connected to the circulation pipeline 2 between the first valve 6 and the laminar cooling assembly 1, and a cold water tank 8, a second water pump 9, and a second valve 10 are sequentially connected to the auxiliary pipeline 7.

[0022] A first temperature sensor 12 is arranged between the laminar cooling assembly 1 at the end of the output roller table 17 and the pinch roll 11. The number of the laminar cooling assemblies 1 is 25 - 29 groups and is arranged along the output roller table 17.

[0023] By connecting to the auxiliary pipeline 7, cooling water can be supplemented into the circulation pipeline 2 to further reduce the water temperature of the cooling water, so as to keep the water temperature of the cooling water not exceeding 43 degrees, thereby ensuring that the temperature of the strip steel after cooling is between 550 - 650 degrees, preferably fluctuating within a small range between 600 - 620 degrees, which is more conducive to ensuring the product quality and product consistency. The first valve 6 and the second valve 10 can be power valves, and solenoid valves or electric butterfly valves can be selected.

[0024] The first temperature sensor 12 provided at the end is used to confirm the amount of cold water to be filled from the auxiliary pipeline 7, so as to control the opening degrees of the first valve 6 and the second valve 10. For precise control, a first pressure sensor can also be provided between the first water pump 5 and the first valve 6, and a second pressure sensor can be provided on the auxiliary pipeline 7 to measure the water pressures in the circulating pipeline 2 and the auxiliary pipeline 7. By coordinating the water pressure and the valve opening degree, the water temperature entering the laminar flow cooling assembly 1 is adjusted.

[0025] To achieve precise control of the cooling water entering the laminar flow cooling assembly 1: a water temperature sensor 13 is provided on the circulating pipeline 2. The water temperature sensor 13 is provided after the connection point of the auxiliary pipeline 7 and the circulating pipeline 2 and before the laminar flow cooling assembly 1 to monitor the water temperature entering the laminar flow cooling assembly 1. The above "after" and "before" are confirmed according to the water flow direction, as Figure 2 shown.

[0026] The above is to adjust the cooling water temperature based on the temperature of the strip after cooling. Since the temperature of the strip exiting the four-high rolling mill fluctuates, the initial temperature of the strip can be monitored to further control the water temperature: a second temperature sensor 15 is added between the four-high rolling mill 14 and the laminar flow cooling assembly 1 to monitor the initial temperature of the strip 16 when it exits the four-high rolling mill 14. The first temperature sensor 12 and the second temperature sensor 15 can use infrared temperature sensors, and firstrate First can be selected, with a measurement range of 0 - 1000 °C.

[0027] For easy automatic control: a CPU and a control circuit are added. The signal outputs of the water temperature sensor 13, the first temperature sensor 12, and the second temperature sensor 15 are connected to the input end of the CPU. The output end of the CPU is respectively connected to a control relay through a triode amplifier circuit, and the relay is respectively connected to control the first water pump 5, the second water pump 9, the first valve 6, and the second valve 10. The CPU can select the C8051F340 series, and the interface can fully meet the requirements. The output of the CPU is connected to the base of the triode amplifier circuit, and the collector of the triode amplifier circuit is connected to the control relay.

[0028] During the laminar flow cooling process, when the water curtain of laminar flow cooling falls, there is a width reduction effect, that is, the width of the lower part of the water curtain is smaller than that of the upper part. Therefore, the laminar flow rack 1-2 adopts a height-adjustable structure: the laminar flow cooling assembly 1 is composed of a bracket 1-1 and a laminar flow rack 1-2, and a water curtain header is arranged on the laminar flow rack 1-2; a slide rail 1-3 is arranged on the bracket 1-1, and a slider matching the slide rail 1-3 is arranged on the laminar flow rack 1-2, and the height of the laminar flow rack 1-2 on the bracket 1-1 is adjustable. The specific structure of laminar flow cooling is that cooling water flows out from the water curtain header, and there is a slit equivalent to the width of the strip steel below the water curtain header, and water flows down from the slit to form a continuous transparent curtain-like laminar flow to cool the upper surface of the steel plate. The above laminar flow cooling involves the cooling of the upper part of the strip steel. In actual production, multiple groups of cooling water nozzles are also installed on the output roller table below the strip steel 16 to cool the lower surface. The number of groups of cooling water nozzles corresponds one by one to the number of groups of the laminar flow cooling assembly 1, and the cooling water nozzles are connected in parallel with the laminar flow cooling assembly 1.

[0029] The height adjustment of the laminar flow rack 1-2 on the bracket 1-1 can be carried out manually or electrically, and the drive of the electric mode can adopt an electric worm and worm gear mechanism.

Claims

1. A laminar flow cooling system with controllable water temperature, characterized in that, Including: A laminar flow cooling component (1) and a circulation pipeline (2); a plurality of the laminar flow cooling components (1) are connected in parallel, and the cooled water flows through the circulation pipeline (2) to a cooling tower (3) and a first water tank (4) in sequence, and then is pumped into the parallel cooling components (1) by a first water pump (5) for recycling; a first valve (6) is arranged between the first water pump (5) and the laminar flow cooling component (1); an auxiliary pipeline (7) is connected to the circulation pipeline (2) between the first valve (6) and the laminar flow cooling component (1), and a cold water tank (8), a second water pump (9), and a second valve (10) are sequentially connected to the auxiliary pipeline (7); a first temperature sensor (12) is arranged between the laminar flow cooling component (1) at the end of the output roller table (17) and a pinch roll (11).

2. The laminar flow cooling system with controllable water temperature according to claim 1, characterized in that A water temperature sensor (13) is arranged on the circulation pipeline (2), and the water temperature sensor (13) is arranged after the connection point of the auxiliary pipeline (7) and the circulation pipeline (2) and before the laminar flow cooling component (1) to monitor the water temperature entering the laminar flow cooling component (1).

3. The laminar flow cooling system with controllable water temperature according to claim 2, characterized in that, A second temperature sensor (15) is added between a four-high rolling mill (14) and the laminar flow cooling component (1) to monitor the initial temperature of the strip steel (16) when it is rolled out of the four-high rolling mill (14).

4. The laminar flow cooling system with controllable water temperature according to claim 3, characterized in that, A CPU and a control circuit are added. The signal outputs of the water temperature sensor (13), the first temperature sensor (12), and the second temperature sensor (15) are connected to the input end of the CPU, and the output end of the CPU is respectively connected to a control relay through a triode amplifier circuit, and the relay is respectively connected to control the first water pump (5), the second water pump (9), the first valve (6), and the second valve (10).

5. The laminar flow cooling system with controllable water temperature according to claim 1, characterized in that, The laminar flow cooling component (1) is composed of a bracket (1-1) and a laminar flow frame (1-2). A water curtain header is arranged on the laminar flow frame (1-2); a slide rail (1-3) is arranged on the bracket (1-1), and a slider matching the slide rail (1-3) is arranged on the laminar flow frame (1-2), and the height of the laminar flow frame (1-2) on the bracket (1-1) is adjustable.

6. The laminar flow cooling system with controllable water temperature according to claim 1, characterized in that, The number of the laminar flow cooling components (1) is 25-29 groups, which are arranged along the output roller table (17).

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