Waste heat recycling device of steelmaking continuous casting machine

Abstract

The utility model discloses a steelmaking continuous casting machine waste heat recycling device which comprises a conveying pipe and a heat exchanger, an annular blocking plate is arranged at the casting blank inlet end of the conveying pipe, a plurality of annular cavities are sequentially formed in the conveying pipe at intervals from the casting blank inlet end to the casting blank outlet end, and each annular cavity is connected with a cold air pipe. A plurality of air nozzles are uniformly distributed on the circumference of the side wall of the side, facing the annular blocking plate, of the annular cavity, cooling cavities are formed between the adjacent annular cavities and between the annular blocking plate and the annular cavities, a plurality of conveying rollers are arranged in the cooling cavities, an exhaust pipe is arranged on the side wall of the side, close to the annular blocking plate, of the cooling cavity, and a heat exchange pipe assembly is arranged in the heat exchanger. The exhaust pipe is communicated with an inlet of the heat exchange pipe assembly, a water supplementing opening is formed in the heat exchanger, an air compressor and a vortex tube which are communicated are arranged on the outer side of the conveying pipe, and a cold air outlet of the vortex tube is communicated with the cold air pipes. In conclusion, the casting device has the advantages of being small in heat loss, high in casting efficiency and high in heat recovery rate.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery technology, specifically to a waste heat recovery and utilization device for a steelmaking continuous casting machine. Background Technology

[0002] The continuous casting process, in which molten steel is continuously poured into billets with specific cross-sectional shapes and dimensions, is called continuous casting. This process requires a complete set of continuous casting equipment. The electromechanical-hydraulic integration of the casting equipment, the continuous casting machine itself, the cutting area equipment, and the dummy bar collection and conveying equipment constitutes the core equipment of continuous casting, conventionally referred to as the continuous casting machine. During the continuous casting process, after the billet leaves the cooling spray device in the secondary cooling chamber, 2-6 meters remain exposed inside. The temperature of this portion of the billet can reach approximately 800℃. When the billet reaches the pre-cutting roller conveyor, the temperature is still around 600℃. The ambient temperature near the casting machine due to heat radiation exceeds 200℃. Current casting machine designs generally use steam exhaust fans to remove some of the heat from the secondary cooling chamber outside the plant, but the roller conveyor area relies solely on natural ambient heat dissipation.

[0003] As mentioned above, the following problems exist in the continuous casting process: First, a large amount of heat from the billet is not effectively utilized due to natural heat dissipation when it is in the roller conveyor, resulting in heat loss and waste. Second, the natural heat dissipation rate of the billet is relatively slow, often leading to low casting efficiency. Third, although some companies have installed waste heat recovery devices in continuous casting machines to remove the heat dissipated by the billet using cold air, this method results in faster cooling of the billet facing the cold air and slower cooling of the billet facing away from the cold air, leading to uneven cooling. Furthermore, the waste heat recovery rate is low, resulting in significant heat waste. Therefore, it is objectively necessary to develop a waste heat recovery device for steelmaking continuous casting machines that minimizes heat loss, increases casting efficiency, and achieves a high heat recovery rate. Utility Model Content

[0004] The purpose of this invention is to provide a waste heat recovery and utilization device for steelmaking continuous casting machines with low heat loss, high casting efficiency, and high heat recovery rate.

[0005] The purpose of this utility model is achieved as follows: It includes a conveying pipe and a heat exchanger. An annular blocking plate is provided at the inlet end of the conveying pipe. Multiple annular cavities are sequentially spaced along the inlet end to the outlet end of the billet inside the conveying pipe. Each annular cavity is connected to a cooling air pipe. Several air jets are evenly distributed circumferentially on the sidewall of the annular cavity facing the annular blocking plate. Cooling chambers are formed between adjacent annular cavities and between the annular blocking plate and the annular cavities. Several conveying rollers are provided within the cooling chambers. An exhaust pipe is provided on the sidewall of the cooling chamber near the annular blocking plate. A heat exchanger tube assembly is provided inside the heat exchanger. The exhaust pipe is connected to the inlet of the heat exchanger tube assembly. A water inlet is provided on the heat exchanger. An air compressor and a vortex tube are connected to the outside of the conveying pipe. The cold air outlet of the vortex tube is connected to each cold air pipe.

[0006] Furthermore, a steam drum is installed above the heat exchanger, and the water-steam delivery pipe at the top of the heat exchanger is connected to the steam inlet of the steam drum, while the condensate outlet of the steam drum is connected to the heat exchanger.

[0007] Furthermore, a gas mixer is installed on the exhaust pipe and the connecting pipe between the exhaust pipe and the heat exchange tube assembly.

[0008] Furthermore, the hot gas outlet of the vortex tube is connected to the gas mixer.

[0009] Furthermore, the jet nozzle is tilted, with the tilt direction facing the centerline of the delivery pipe.

[0010] Furthermore, a jacket is provided on the outer wall of the conveying pipe. An inlet is provided on the jacket near the billet outlet end of the conveying pipe, and an outlet is provided on the jacket near the billet inlet end of the conveying pipe. The outlet is connected to the water supply port of the heat exchanger.

[0011] Furthermore, an agitator is installed inside the heat exchanger below the heat exchange tube assembly.

[0012] In operation, this invention connects the billet inlet end of the conveying pipe to the discharge port of the continuous casting machine, and the billet outlet end of the conveying pipe to the pre-cutting roller conveyor. An air compressor sends air at a certain pressure into the vortex tube to generate cold air, which is discharged from the cold air outlet, enters each annular cavity through the cold air pipe, and is then sprayed into each cooling cavity from the jet nozzle. At the same time, the billet enters the conveying pipe from the billet inlet end, and the cold air sprayed from the annular cavity flows towards the billet, carrying away the heat emitted by the billet and obtaining hot air, which is discharged from the exhaust pipe and sent into the heat exchange tube assembly in the heat exchanger to exchange heat with the cold water flowing in the heat exchanger. The cold water absorbs the heat in the hot air to form water vapor, which can be used for enterprise production or power generation. In the above process, the heat emitted by the billet in each cooling chamber is absorbed by cold air, forming hot air which is then introduced into the heat exchanger. Water absorbs the heat from the hot air in the heat exchanger, and the water evaporates to form steam. This method collects the heat emitted by the billet at the roller conveyor and utilizes this heat to produce steam, achieving the purpose of utilizing the billet's residual heat and significantly reducing heat loss and waste. Secondly, this invention incorporates an air compressor and a vortex tube. The vortex tube generates cooler air, which is used to cool the billet. The higher temperature between the cool air and the billet results in higher heat exchange efficiency, increasing the billet's heat dissipation rate and improving casting efficiency. Furthermore, in this invention, the cool air first enters the annular cavity and then exits from the jet nozzles on the side wall of the annular cavity. Because the jet nozzles are evenly distributed circumferentially, the cool air blows onto the billet simultaneously from all directions. This ensures that all sides of the billet have the same cooling rate, thereby ensuring uniform cooling and improving the recovery rate of residual heat, further reducing heat loss and waste. In summary, this invention has the advantages of low heat loss, high casting efficiency, and high heat recovery rate. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0014] Figure 2 for Figure 1 A magnified structural diagram of node A in the middle;

[0015] Figure 3 for Figure 1 Schematic diagram of the cross-sectional structure of BB;

[0016] In the diagram: 1-Conveying pipe, 2-Heat exchanger, 3-Annular plug, 4-Annular cavity, 5-Cold air pipe, 6-Jet nozzle, 7-Exhaust pipe, 8-Heat exchanger tube assembly, 9-Air compressor, 10-Vortex tube, 11-Steam drum, 12-Gas mixer, 13-Jacket, 14-Inlet, 15-Outlet, 16-Agitator, 17-Conveying roller, 18-Casting billet. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings, but this description is not intended to limit the present invention in any way. Any changes or improvements made based on the present invention shall fall within the protection scope of the present invention.

[0018] like Figures 1-3 As shown, this utility model includes a conveying pipe 1 and a heat exchanger 2. An annular blocking plate 3 is provided at the inlet end of the conveying pipe 1. The billet 18 enters the conveying pipe 1 through the hollow portion of the annular blocking plate 3. The annular blocking plate 3 also prevents hot air from escaping. Multiple annular cavities 4 are sequentially spaced along the billet inlet end to the billet outlet end inside the conveying pipe 1. Each annular cavity 4 is connected to a cooling air pipe 5. Several air jets 6 are evenly distributed circumferentially on the sidewall of the annular cavity 4 facing the annular blocking plate 3. Cooling chambers are formed between adjacent annular cavities 4 and between the annular blocking plate 3 and the annular cavity 4. Several conveying rollers 17 are provided within the cooling chambers. The conveying rollers 17 are existing equipment used for casting... The billet 18 is supported and transported. An exhaust pipe 7 is provided on the side wall of the cooling chamber near the annular blocking plate 3. A heat exchange tube assembly 8 is provided in the heat exchanger 2. The heat exchange tube assembly 8 is existing technology and is used for heat exchange with cold water. The exhaust pipe 7 is connected to the inlet of the heat exchange tube assembly 8. A water inlet is provided on the heat exchanger 2. An air compressor 9 and a vortex tube 10 are connected on the outside of the conveying pipe 1. Both the air compressor 9 and the vortex tube 10 are existing equipment. The air compressor 9 is used to generate compressed gas. The vortex tube 10 can cause the high-speed airflow to generate a vortex and separate the cold and hot airflows. In this utility model, the cold airflow is used to cool the billet 18. The cold air outlet of the vortex tube 10 is connected to each cold air pipe 5.

[0019] In operation, the billet inlet end of the conveying pipe 1 is connected to the discharge port of the continuous casting machine, and the billet outlet end of the conveying pipe 1 is connected to the pre-cutting roller conveyor. The air compressor 9 sends air at a certain pressure into the vortex tube 10 to generate cold air, which is discharged from the cold air outlet, enters each annular cavity 4 through the cold air pipe 5, and is then sprayed into each cooling cavity from the jet nozzle 6. At the same time, the billet 18 enters the conveying pipe 1 from the billet inlet end. The cold air sprayed from the annular cavity 4 flows towards the billet 18, carrying away the heat emitted by the billet 18 and obtaining hot air, which is discharged from the exhaust pipe 7 and sent into the heat exchange tube assembly 8 in the heat exchanger 2 to exchange heat with the cold water introduced into the heat exchanger 2. The cold water absorbs the heat in the hot air to form water vapor, which can be used for enterprise production or power generation.

[0020] In the above process, the heat emitted by the casting billet 18 in each cooling chamber is absorbed by cold air, forming hot air which is then introduced into the heat exchanger 2. In the heat exchanger 2, water absorbs the heat from the hot air, and the water evaporates to form water vapor. This method collects the heat emitted by the casting billet 18 at the roller conveyor section and utilizes this heat to produce water vapor, achieving the purpose of utilizing the waste heat of the casting billet 18 and significantly reducing heat loss and waste. Secondly, in this invention, an air compressor 9 and a vortex tube 10 are provided. The vortex tube 10 generates cool air at a lower temperature, which is then used to heat the casting billet 18. The cooling process increases the temperature between the cold air and the billet 18, resulting in higher heat exchange efficiency and improved heat dissipation speed of the billet 18, thus improving casting efficiency. Furthermore, in this invention, the cold air first enters the annular cavity 4 and then exits from the air jets 6 on the side wall of the annular cavity 4. Since the air jets 6 are evenly distributed circumferentially, the cold air blows onto the billet 18 simultaneously from all directions. This ensures that all sides of the billet 18 have the same cooling rate, thereby guaranteeing the uniformity of cooling and improving the recovery rate of residual heat from the billet 18, reducing heat loss and waste.

[0021] A steam drum 11 is installed above the heat exchanger 2. The steam-water delivery pipe at the top of the heat exchanger 2 is connected to the steam inlet of the steam drum 11, and the condensate outlet of the steam drum 11 is connected to the heat exchanger 2. The steam drum 11 is an existing device used for steam storage and also for gas-liquid separation to separate the moisture from the steam. In this invention, the separated condensate is returned to the heat exchanger 2 to continue participating in waste heat recovery, which can improve the steam production efficiency, save water resources, and improve the utilization rate of water resources.

[0022] A gas mixer 12 is installed on the connecting pipe between the exhaust pipe 7 and the heat exchange tube assembly 8. The gas mixer 12 is an existing device. In this invention, cold air is introduced into each cooling chamber to absorb the heat emitted by the billet 18 in each cooling chamber. During operation, the billet 18 moves from the billet inlet end of the conveying pipe 1 to the billet outlet end, and exchanges heat with the cold air in each cooling chamber in turn. Its temperature gradually decreases, and the temperature of the hot air formed also gradually decreases. This results in the discharge of hot air at different temperatures. In order to facilitate the utilization of the hot air, all the hot air is introduced into the gas mixer 12 for mixing, averaging the temperature of the hot air output, stabilizing the heat exchange efficiency of the subsequent heat exchanger 2, and thus stabilizing the output steam temperature, which facilitates the utilization of steam.

[0023] The hot gas outlet of the vortex tube 10 is connected to the gas mixer 12. The hot gas outlet of the vortex tube 10 will discharge hot gas. Directly venting it will still cause some heat loss. By passing it into the gas mixer 12 and mixing it with the other hot gas, the heat loss can be reduced.

[0024] The jet nozzle 6 is inclined, with the inclination direction facing the centerline of the conveying pipe 1. The cold air is blown directly onto the billet 18 and comes into direct contact with the billet 18, improving the heat exchange efficiency between the cold air and the billet 18.

[0025] A jacket 13 is provided on the outer wall of the conveying pipe 1. A water inlet 14 is provided on the jacket 13 near the billet outlet end of the conveying pipe 1, and a water outlet 15 is provided on the jacket 13 near the billet inlet end of the conveying pipe 1. The water outlet 15 is connected to the water supply port of the heat exchanger 2. When this utility model is running, cold air is injected into the conveying pipe 1 to absorb the heat dissipated by the billet 18 and form hot air. Some heat will still be dissipated from the closed conveying pipe 1. In order to reduce the waste of heat, a jacket 13 is provided on the outer wall of the conveying pipe 1. Cold water is introduced into the jacket 13. The cold water can absorb this part of the heat and avoid the waste of heat. After the cold water is preheated, it is introduced into the heat exchanger 2, which can increase the steam output.

[0026] A stirrer 16 is installed inside the heat exchanger 2 below the heat exchange tube assembly 8. The stirrer 16 is an existing device, installed inside the heat exchanger 2, used to agitate the water flow inside the heat exchanger 2, so that the water inside the heat exchanger 2 is in a flowing state, which facilitates the improvement of the heat exchange efficiency between the water and the heat exchange tube assembly 8.

Claims

1. A waste heat recovery and utilization device for a steelmaking continuous casting machine, comprising a conveying pipe (1) and a heat exchanger (2), characterized in that: An annular blocking plate (3) is provided at the inlet end of the conveying pipe (1). Multiple annular cavities (4) are sequentially spaced along the inlet end to the outlet end of the billet inside the conveying pipe (1). Each annular cavity (4) is connected to a cooling air pipe (5). Several air jets (6) are evenly distributed circumferentially on the sidewall of the annular cavity (4) facing the annular blocking plate (3). Cooling chambers are formed between adjacent annular cavities (4) and between the annular blocking plate (3) and the annular cavity (4). Several conveying rollers (17) are provided inside the cooling cavity. An exhaust pipe (7) is provided on the side wall of the cooling cavity near the annular block plate (3). A heat exchange tube assembly (8) is provided inside the heat exchanger (2). The exhaust pipe (7) is connected to the inlet of the heat exchange tube assembly (8). A water inlet is provided on the heat exchanger (2). An air compressor (9) and a vortex tube (10) are connected to the outside of the conveying pipe (1). The cold air outlet of the vortex tube (10) is connected to each cold air pipe (5).

2. The waste heat recovery and utilization device for a steelmaking continuous casting machine according to claim 1, characterized in that: A steam drum (11) is provided above the heat exchanger (2). The water vapor delivery pipe at the top of the heat exchanger (2) is connected to the steam inlet of the steam drum (11), and the condensate outlet of the steam drum (11) is connected to the heat exchanger (2).

3. The waste heat recovery and utilization device for a steelmaking continuous casting machine according to claim 1, characterized in that: A gas mixer (12) is provided on the connecting pipe between the exhaust pipe (7) and the heat exchange tube assembly (8).

4. The waste heat recovery and utilization device for a steelmaking continuous casting machine according to claim 3, characterized in that: The hot gas outlet of the vortex tube (10) is connected to the gas mixer (12).

5. The waste heat recovery and utilization device for a steelmaking continuous casting machine according to claim 1, characterized in that: The jet nozzle (6) is inclined, with the inclination direction facing the center line of the delivery pipe (1).

6. The waste heat recovery and utilization device for a steelmaking continuous casting machine according to claim 1, characterized in that: A jacket (13) is provided on the outer wall of the conveying pipe (1). An inlet (14) is provided on the jacket (13) near the billet outlet end of the conveying pipe (1). An outlet (15) is provided on the jacket (13) near the billet inlet end of the conveying pipe (1). The outlet (15) is connected to the water supply port of the heat exchanger (2).

7. The waste heat recovery and utilization device for a continuous casting machine in steelmaking according to claim 1, characterized in that: A stirrer (16) is provided inside the heat exchanger (2) below the heat exchange tube assembly (8).

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