A device and control method for cooling high-temperature hot sand and cast iron scrap

Abstract

The application discloses a device and a control method for cooling high-temperature hot sand and cast scrap iron, and relates to cooling equipment. The device comprises a box body, a box cover covering the box body, two circular chambers with local overlap arranged in the box body, air inlets and air outlets respectively arranged on two sides of the box body and communicated with the circular chambers, a rotating shaft rotatably arranged in each of the circular chambers, at least two symmetrical distributing plates fixed on the rotating shaft, a long slot penetrating through the distributing plate and arranged in the distributing plate, a scraping end arranged at the lower part of the distributing plate and contacted with the circular chamber, and a throwing piece arranged at the end of the distributing plate. A cooling liquid tank is arranged below the box body and communicated with a liquid storage tank through a circulating pipeline. The application solves the problem of uneven material cooling and realizes the purpose of faster material cooling treatment.

Description

Technical Field

[0001] This invention relates to cooling equipment, and more specifically, to an apparatus and control method for cooling high-temperature hot sand and cast iron slag. Background Technology

[0002] In the casting process, a large amount of used sand and cast iron scrap are generated after casting. These materials are recycled through crushing, high-temperature heating, cooling, and magnetic separation. In existing technology, the heated hot sand and cast iron scrap are sent to a box-type air-cooling device for cooling. However, existing box-type air-cooling devices typically employ a single-chamber, unidirectional airflow design. Although there are agitators inside the chamber to agitate the materials, material accumulation still occurs, leading to uneven cooling and low heat exchange efficiency. Furthermore, single-air cooling is slow when dealing with materials at high temperatures, affecting production efficiency; increasing the airflow will blow away some of the used sand. Therefore, there is an urgent need for a device that can efficiently and uniformly cool high-temperature hot sand and cast iron scrap. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a device and control method for cooling high-temperature hot sand and cast iron slag, thereby solving the problem of uneven material cooling and achieving the goal of faster material cooling.

[0004] The present invention discloses a device for cooling high-temperature hot sand and cast iron scrap, comprising a housing and a cover covering the housing; the housing has two partially overlapping circular chambers, and air inlets and outlets communicating with the circular chambers are respectively provided on both sides of the housing; a rotating shaft is rotatably installed in each of the two circular chambers, and at least two symmetrically arranged uniform material plates are fixed on the rotating shafts. A long groove penetrating the uniform material plate is opened in the uniform material plate, and a scraping end is provided at the lower part of the uniform material plate, which contacts the circular chamber; an inclined throwing element is installed at the end of the uniform material plate; a coolant tank is installed below the housing, and the coolant tank is connected to a storage tank through a circulation pipeline.

[0005] Preferably, the two rotating shafts rotate in opposite directions and at the same speed, but the phase of one rotating shaft lags behind the phase of the other rotating shaft by 20°-45°.

[0006] Preferably, the box cover is provided with a feeding interface, and each of the circular chambers is provided with a discharge port below, and a sealing top block driven by a lifting device is inserted into the discharge port.

[0007] Preferably, the sealing top block is composed of an integrated adapter block and a conical stop block. The adapter block matches the discharge port and is inserted into the discharge port to form a seal. The conical stop block is connected to the lifting device.

[0008] Preferably, the device further includes a backup water tank, which is connected to the storage tank via a second circulation pipeline.

[0009] Preferably, the cross-section of the ejector is convex lens-shaped.

[0010] Preferably, the tilt angle of the throwing element is 120°-145°.

[0011] A control method based on the aforementioned device, the method comprising: The temperature of the material inside the circular chamber is obtained. If the material temperature is greater than or equal to a set high temperature threshold, the first circulation pipeline is activated to allow the coolant in the storage tank to form a water circulation between the storage tank and the coolant tank, while the rotating shaft is controlled to run at a set first speed. If the material temperature is less than a set low temperature threshold, the first circulation pipeline is deactivated, while the rotating shaft is controlled to run at a set second speed, and cooling gas is supplied to the circular chamber through the air inlet until the temperature of the material in the circular chamber drops below the set temperature.

[0012] Preferably, the first rotational speed is less than the second rotational speed.

[0013] Preferably, the liquid temperature of the coolant in the storage tank is monitored in real time. If the liquid temperature is less than a set liquid temperature threshold, the first circulation pipeline is kept active. If the liquid temperature is greater than or equal to the set liquid temperature threshold, the first circulation pipeline is deactivated and the second circulation pipeline is activated.

[0014] Beneficial effects The advantages of this invention are: 1. This invention employs a time-sharing design that combines liquid cooling and air cooling, which can effectively recover heat from the material. At the same time, the design of two circular chambers combined with a material throwing device greatly improves the mixing uniformity, thereby solving the problem of uneven material cooling and achieving the goal of faster material cooling.

[0015] 2. By scraping and tumbling the material with a uniform material plate, and combining the material leakage effect of the long groove set on the uniform material plate, a material layer is formed, which realizes the layering of the material. This ensures that the material at each position in the circular chamber can better exchange heat with the coolant in the cooling water tank at the bottom of the circular chamber, thereby achieving the cooling of the material. Attached Figure Description

[0016] Figure 1This is a front view of the device of the present invention.

[0017] Figure 2 This is a schematic diagram of the front structure of the box body with the lid installed according to the present invention.

[0018] Figure 3 This is a top view of the housing structure of the present invention.

[0019] Figure 4 This is a front view of the rotating shaft with the material leveling plate installed according to the present invention.

[0020] Figure 5 This is a schematic diagram of the cross-sectional structure of the uniform material plate of the present invention.

[0021] The components are as follows: 10. Box body; 11. Circular chamber; 12. Air inlet; 13. Air outlet; 14. Material outlet; 20. Box cover; 21. Feeding interface; 30. Rotating shaft; 31. Material leveling plate; 311. Long groove; 312. Scraper end; 32. Material throwing component; 40. Coolant tank; 41. Circulation pipeline one; 42. Liquid storage tank; 50. Sealing top block; 51. Adaptor block; 52. Conical stop block; 60. Spare water tank; 61. Circulation pipeline two. Detailed Implementation

[0022] The present invention will be further described below with reference to embodiments, but this does not constitute any limitation on the present invention. Any limited modifications made by any person within the scope of the claims of the present invention are still within the scope of the claims of the present invention. See Figures 1-5 This invention discloses a device for cooling high-temperature hot sand and cast iron scrap, comprising a housing 10 and a cover 20 covering the housing 10. The housing 10 contains two partially overlapping circular chambers 11. Air inlets 12 and outlets 13, respectively connected to the circular chambers 11, are located on both sides of the housing 10. A rotating shaft 30 is rotatably mounted in each of the two circular chambers 11. The rotating shafts 30 are driven by an externally mounted geared motor (not shown). Two symmetrically arranged uniform material plates 31 are fixed on the rotating shafts 30. Each uniform material plate 31 has a long groove 311 penetrating it. A scraping end 312 is located at the lower part of each uniform material plate 31, contacting the circular chamber 11. An inclined throwing element 32 is mounted at the end of each uniform material plate 31. A coolant tank 40 is installed below the housing 10, and the coolant tank 40 is connected to a storage tank 42 via a circulation pipe 41.

[0023] During operation, the rotating shaft 30 drives the two uniform material plates 31 fixed thereon to rotate. As the uniform material plates 31 rotate, their lower scraping ends 312 continuously contact the bottom of the circular chamber 11, scraping up the high-temperature material at the bottom. The scraped material tumbles as the uniform material plates 31 rotate, effectively preventing material accumulation. As the accumulated material reaches or exceeds the height of the long trough 311, some material leaks down through the trough, forming a layer of tumbling material behind the uniform material plates 31. In short, by combining scraping and tumbling with leakage to reform the material layer, material layering is achieved, ensuring better heat exchange between the material at various points in the circular chamber 11 and the coolant in the cooling water tank 40 at the bottom of the circular chamber 11, thus cooling the material.

[0024] Furthermore, during the rotation of the material driven by the rotating shaft 30, the material accumulates at the end of the uniform plate 31 due to material buildup and centrifugal force. This invention utilizes inclined throwing elements 32 to throw the material from one circular chamber 11 to another along a specific trajectory, achieving material exchange between the two chambers and preventing excessively high temperatures in one chamber. More importantly, during the cooling process, the thrown material makes better contact with the cooling air, resulting in more efficient and rapid final cooling.

[0025] When the material is at a high temperature, it is first cooled by a coolant. The heat from the material is conducted through the wall of the circular chamber 11 to the coolant in the coolant tank 40 installed below the casing 10. The coolant circulates between the storage tank 42 and the coolant tank 40 through the circulation pipe 41, carrying away the heat. This coolant, after heat exchange, can be used for preheating in the initial stage of processing cast iron scrap. Because the material cools down and the coolant heats up during the heat exchange, the heat exchange rate between the material and the coolant decreases. To avoid excessively long cooling times, once the material reaches a set temperature, the coolant cooling function is deactivated, and the cold air cooling function is activated to cool the material to the target temperature. This design, which uses liquid cooling and air cooling in a time-sharing manner, effectively recovers heat from the material. Combined with a unique material throwing design, it greatly improves mixing uniformity and achieves faster material cooling.

[0026] In one embodiment, the two rotating shafts 30 mentioned above rotate in opposite directions. The two shafts 30 rotate at the same speed, but the phase of one shaft 30 lags behind the phase of the other shaft 30 by 30°. In this configuration, although the rotation speeds of the two shafts 30 are exactly the same, ensuring the smooth operation of the system, the 30° phase difference means that the uniform material plate 31 and the throwing element 32 attached to the two shafts 30 will never symmetrically meet at the same point in the overlapping area. This means that when the throwing element 32 on one shaft 30 is at its highest speed, the throwing element 32 on the other shaft 30 may be in the stage of lifting material. This asynchronous action creates an asymmetric mechanical stirring flow field in the overlapping area. This asymmetric flow field effectively avoids the periodic stress peaks and localized material accumulation that may result from symmetrical impacts, causing the material in the entire circular chamber 11 to undergo a mixing effect similar to a "kneading" effect, achieving efficient cooling of the material.

[0027] In one embodiment, the cover 20 is provided with a feed inlet 21, and each circular chamber 11 has a discharge port 14 at its bottom. A sealing block 50 driven by a lifter is inserted into the discharge port 14. The sealing block 50 is inserted into the discharge port 14 to seal the bottom of the circular chamber 11, providing a sealed mixing and cooling space for the material and reducing the amount of dust emitted. This arrangement enables the feeding and discharging of materials. When the material temperature drops to a set range, the lifter drives the sealing block 50 to move downwards and exit from the discharge port 14, allowing the cooled material to be continuously discharged from the discharge port 14 under the pushing action of the rotating uniform plate 31.

[0028] Furthermore, in this embodiment, the sealing top block 50 consists of an integrally structured adapter block 51 and a conical stop block 52. The adapter block 51 matches the discharge port 14 and is inserted into the discharge port 14 to form a seal. The conical stop block 52 is connected to the lifter. The shape of the adapter block 51 precisely matches the discharge port 14. When fully inserted, its upper surface is flush with or slightly lower than the bottom plate of the circular chamber 11, preventing the adapter block 51 from obstructing the material leveling plate 31. The conical stop block 52 below it has a good centering and guiding effect. When the lifter drives the sealing top block 50 to rise and reset, it ensures that the adapter block 51 is accurately inserted into the discharge port 14 and stops the insertion depth of the adapter block 51, thereby ensuring the consistency and reliability of each sealing operation.

[0029] In one embodiment, the device further includes a backup water tank 60, which is connected to the storage tank 42 via a second circulation pipe 61. The backup water tank 60 serves as an auxiliary cooling source and stores backup coolant. When the system primarily relies on the storage tank 42 for water circulation cooling, the backup water tank 60 and its connected second circulation pipe 61 are in standby mode. When the control system detects the need to activate backup cooling capacity, it can switch to activating the second circulation pipe 61, introducing coolant with a lower temperature from the backup water tank 60 into the cooling circuit, thereby preventing the coolant temperature in the storage tank 42 from approaching the material temperature and affecting the material's cooling effect.

[0030] In one embodiment, the cross-section of the throwing element 32 is convex lens-shaped, and the tilt angle of the throwing element 32 is 120°-145°. The convex lens-shaped cross-section of the throwing element 32, meaning its two sides are smooth, outward-convex curved surfaces, significantly reduces the frictional resistance and adhesion probability of the material to the surface of the throwing element 32 during rotational mixing, making it easier for the material to be thrown out and less likely to accumulate on the component. The 120°-145° tilt angle range is the angle between the throwing surface of the throwing element 32 and the uniform plate 31. Within this angle range, the thrust exerted by the throwing element 32 on the material will generate a large upward velocity component and a moderate velocity component towards the center of the chamber. As a specific implementation, when a 145° tilt angle is used, the farthest point of the parabolic trajectory of the material being thrown is closer to the pivot point on the circular chamber 11, and the lateral range of the material being thrown (i.e., the range between the throwing component 32 and the pivot point in the other chamber) is larger, which is suitable for materials with relatively uniform particles; when a 120° tilt angle is used, the material is mainly concentrated in the position far away from the pivot point, that is, more of it is thrown into the overlapping and interactive area of ​​the two circular chambers 11, which enhances the convection mixing of the material and is suitable for processing large pieces of cast iron that are not easy to mix.

[0031] It should be noted that, in some optional embodiments, the housing 10 and the cover 20, as the main pressure-bearing and sealing structures, can be made of high-strength gray cast iron and then aged to ensure their dimensional stability under alternating thermal stress. The inner wall of the circular chamber 11 can be high-frequency quenched or hard chrome plated to improve its wear resistance and form a long-lasting friction pair with the scraper end 312. However, a heat-conducting plate (such as an aluminum plate or a copper plate) can be embedded in its bottom, and the heat-conducting plate contacts the coolant tank 40 to ensure heat conduction efficiency. Core components that come into contact with high-temperature materials, such as the uniform material plate 31, the throwing component 32, and the rotating shaft 30, can be made of heat-resistant cast steel (such as ZG40Cr24). The coolant tank 40 is an integral water jacket structure surrounding the bottom of the two circular chambers 11, and it is provided with corresponding clearance grooves, such as the clearance groove of the sealing top block. The coolant tank 40 can be equipped with guide ribs to guide the coolant along a specific serpentine flow path, increasing the heat exchange path and efficiency. Both circulation pipe 1 41 and circulation pipe 2 61 are equipped with independent circulation pumps and solenoid control valves.

[0032] In some alternative embodiments, the scraper end 312 is not necessarily a sharp corner of the material leveling plate 31 body. Instead, it can be a wear-resistant scraper detachably mounted on the lower part of the material leveling plate 31, made of hard alloy or ceramic for easy replacement after wear. A rotary feed valve or star-shaped unloader can be installed inside the feed inlet 21 to maintain stable airflow pressure inside the housing 10 while feeding. The control system, the lifting device, and the power source for driving the rotating shaft 30 are all controlled by a PLC.

[0033] The present invention also provides a control method based on the device described above, the method being: Step S101: Obtain the material temperature inside the circular chamber 11.

[0034] Step S102: Determine whether the material temperature is greater than or equal to the set high temperature threshold.

[0035] In step S103, if yes, then activate circulation pipeline 41 to make the coolant in reservoir 42 form a water circulation in reservoir 42 and coolant tank 40, while controlling the rotating shaft 30 to run at a set first speed.

[0036] In step S104, if the material temperature is lower than the set low temperature threshold, the circulation pipeline 41 is stopped, and the rotating shaft 30 is controlled to run at the set second speed. Cooling gas is supplied to the circular chamber 11 through the air inlet 12 until the temperature of the material in the circular chamber 11 drops below the set temperature.

[0037] This control method allows the device to automatically select the optimal cooling mode based on the initial temperature of the feed material. When the material is at an extremely high temperature, powerful water circulation cooling is activated, while the material is stirred at a lower initial speed to increase its residence time at the bottom of the chamber, allowing for more thorough heat transfer between the material and the chamber wall circulated with coolant. Once the material has undergone initial cooling and reached a certain low temperature threshold, the method automatically switches to pure air cooling mode and increases the speed to a second speed. At this point, the material is more vigorously thrown and agitated, engaging in high-speed convective heat exchange with the flowing cooling gas, while simultaneously preventing the material from caking due to rapid cooling caused by water cooling. This segmented intelligent control strategy based on real-time temperature balances cooling rate, energy consumption, and the adaptability of the material to subsequent processes.

[0038] In one embodiment, the first rotational speed is lower than the second rotational speed. This configuration is significant because, during the high-temperature water cooling stage, heat dissipation through heat conduction is the primary efficiency. Therefore, using a lower first rotational speed prolongs the contact time between the material and the cooling surface at the bottom of the chamber, optimizing the solid-liquid heat exchange process and reducing dust generated. When switching to air-cooling mode, the main heat exchange mechanism becomes gas-solid convection heat exchange. At this time, a higher second rotational speed is used to accelerate the material's circulation frequency, greatly increasing the effective contact area and time between the material and the cooling airflow. This compensates for the lower heat transfer coefficient of air cooling, ensuring a smooth transition in the overall cooling rhythm.

[0039] In one embodiment, the coolant temperature in the reservoir 42 is monitored in real time. If the coolant temperature is lower than a set temperature threshold, circulation line 41 remains active; if the coolant temperature is greater than or equal to the set temperature threshold, circulation line 41 is deactivated and circulation line 61 is activated. This control logic enables adaptive switching of the coolant circuit. When the coolant temperature in the reservoir 42 rises above the set temperature threshold due to continuous heat absorption, it indicates that its primary cooling capacity is nearing saturation. In this case, keeping circulation line 41 active is ineffective or even harmful. At this point, circulation line 41 is automatically deactivated, and circulation line 61, connected to the backup coolant tank 60, is activated, switching the heat dissipation task to the backup coolant circuit with sufficient heat capacity and a lower temperature. This ensures the thermal stability of the cooling process, avoids a decrease in the overall cooling efficiency of the device due to the coolant's own temperature rise, and achieves seamless thermal switching without interrupting operation.

[0040] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention, and these will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. An apparatus for cooling high-temperature hot sand and cast iron scrap, characterized in that, The enclosure includes a housing (10) and a cover (20) covering the housing (10); the housing (10) has two partially overlapping circular chambers (11), and the housing (10) has an air inlet (12) and an air outlet (13) on each side of the circular chambers (11); a rotating shaft (30) is rotatably installed in each of the two circular chambers (11), and at least two symmetrically arranged uniform plates (31) are fixed on the rotating shaft (30). A long groove (311) is provided in the material plate (31) through the material leveling plate (31). A scraping end (312) is provided at the lower part of the material leveling plate (31). The scraping end (312) is in contact with the circular cavity (11). An inclined throwing element (32) is installed at the end of the material leveling plate (31). A coolant tank (40) is installed below the box body (10). The coolant tank (40) is connected to a storage tank (42) through a circulation pipeline (41).

2. The apparatus for cooling high-temperature hot sand and cast iron scrap according to claim 1, characterized in that, The two rotating shafts (30) rotate in opposite directions and rotate at the same speed, but the phase of one shaft lags behind the phase of the other shaft by 20°-45°.

3. The apparatus for cooling high-temperature hot sand and cast iron scrap according to claim 1, characterized in that, The box cover (20) is provided with a feeding interface (21), and each of the circular chambers (11) is provided with a discharge port (14) below it. A sealing top block (50) driven by a lifting device is inserted into the discharge port (14).

4. The apparatus for cooling high-temperature hot sand and cast iron scrap according to claim 3, characterized in that, The sealing top block (50) is composed of an adapter block (51) and a conical stop block (52) with an integral structure. The adapter block (51) matches the discharge port (14) and is inserted into the discharge port (14) to form a seal on the discharge port (14). The conical stop block (52) is connected to the lifting device.

5. The apparatus for cooling high-temperature hot sand and cast iron scrap according to claim 1, characterized in that, The device also includes a backup water tank (60), which is connected to the storage tank (42) via a second circulation pipeline (61).

6. The apparatus for cooling high-temperature hot sand and cast iron scrap according to claim 1, characterized in that, The cross-section of the ejector (32) is convex lens-shaped.

7. The apparatus for cooling high-temperature hot sand and cast iron scrap according to claim 1, characterized in that, The tilt angle of the throwing component (32) is 120°-145°.

8. A control method based on the device as described in any one of claims 1-7, characterized in that, The method is as follows: The material temperature in the circular chamber (11) is obtained. If the material temperature is greater than or equal to the set high temperature threshold, the first circulation pipeline (41) is activated to make the coolant in the storage tank (42) form a water circulation in the storage tank (42) and the coolant tank (40), and at the same time, the rotating shaft (30) is controlled to run at the set first speed. If the material temperature is less than the set low temperature threshold, the first circulation pipeline (41) is deactivated, and at the same time, the rotating shaft (30) is controlled to run at the set second speed, and cooling gas is supplied to the circular chamber (11) through the air inlet (12) until the temperature of the material in the circular chamber (11) drops below the set temperature.

9. The control method according to claim 8, characterized in that, The first rotational speed is less than the second rotational speed.

10. The control method according to claim 8, characterized in that, The liquid temperature of the coolant in the storage tank (42) is monitored in real time. If the liquid temperature is less than the set liquid temperature threshold, the first circulation pipe (41) is kept active. If the liquid temperature is greater than or equal to the set liquid temperature threshold, the first circulation pipe (41) is deactivated and the second circulation pipe (61) is activated.

Images