A cooling device for a sand mill
Efficient and uniform cooling was achieved on the sand mill by using liquid nitrogen storage tanks and cryogenic liquid delivery pipeline systems, which solved the problem of poor performance of existing cooling systems and improved grinding efficiency and product quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI RUJIA ELECTROMECHANICAL TECH CO LTD
- Filing Date
- 2025-06-16
- Publication Date
- 2026-06-23
AI Technical Summary
The existing cooling system of the sand mill is ineffective, requiring frequent replacement of the cooling medium, which leads to high costs and makes it difficult to effectively control the internal temperature of the mill.
The system employs a liquid nitrogen storage tank, cryogenic liquid delivery pipeline, and cryogenic liquid nitrogen pump system. Liquid nitrogen is evenly distributed on the surface of the grinding chamber through guide strips. The low boiling point of liquid nitrogen allows it to quickly absorb heat, and the vaporized nitrogen forms an inert atmosphere to protect the material. Combined with a liquid level sensor and controller, the liquid nitrogen delivery rate is automatically adjusted to ensure stable cooling.
It achieves efficient and uniform cooling, improves grinding efficiency, reduces liquid nitrogen consumption and energy consumption, prevents material oxidation, and improves product qualification rate.
Smart Images
Figure CN224398084U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of sand mill cooling technology, specifically relating to a cooling device for a sand mill. Background Technology
[0002] Sand mills are the most adaptable, advanced, and efficient grinding equipment for materials. They have the narrowest grinding chamber, the smallest lever gap, and the most concentrated grinding energy. Combined with a high-performance cooling system and an automatic control system, they can achieve continuous material processing and continuous discharge, which greatly improves production efficiency. However, the existing cooling systems used for sand mills are simple and ineffective. They require the use of cooling media for cooling, and the cooling media needs to be replaced frequently, which is costly.
[0003] For example, in the Chinese utility model patent CN212653276U entitled "Rapid Cooling Device for Sand Mill Coolant," the above-mentioned technology involves adding liquid nitrogen to a liquid nitrogen container, filling the heat exchanger and pipelines with coolant, and turning on the circulation pump. The liquid nitrogen can quickly cool the coolant. After absorbing heat, the liquid nitrogen vaporizes and is introduced into the sand mill through the outlet pipe for inert gas protection. However, the above-mentioned technology requires cooling the coolant in the cooling pipes before cooling the sand mill. When the liquid nitrogen is unavailable, it needs to be manually replenished, causing the internal temperature of the mill to continue to rise. This also increases labor costs and results in poor cooling effect and slow cooling efficiency inside the mill. Therefore, a cooling device for sand mills is needed. Utility Model Content
[0004] The purpose of this utility model is to provide a cooling device for a sand mill that is simple in structure and reasonably designed in order to solve the above problems.
[0005] This utility model achieves the above objectives through the following technical solutions:
[0006] A cooling device for a sand mill includes a liquid nitrogen storage tank, a cryogenic liquid delivery pipeline fixedly connected to one side of the liquid nitrogen storage tank, a cooling chamber provided at one end of the cryogenic liquid delivery pipeline, a grinding chamber provided inside the cooling chamber, a cryogenic liquid nitrogen pump provided on the cryogenic liquid delivery pipeline, a feeding chamber fixedly connected to one side of the grinding chamber, a feed inlet fixedly connected to the top of the feeding chamber, and a discharge chamber fixedly connected to one side of the grinding chamber.
[0007] As a further optimization of this utility model, the cooling chamber has a guide strip fixedly fitted to the surface of the grinding chamber, the surface of the cooling chamber is provided with a liquid nitrogen port, and one end of the cryogenic liquid delivery pipeline is fixedly connected to the cooling chamber through the liquid nitrogen port.
[0008] As a further optimization of this utility model, the top of the cooling chamber is fixedly connected to a plurality of collection pipes, the top of the plurality of collection pipes is fixedly connected to a nitrogen collection tank, a safety valve is provided on one side of the nitrogen collection tank, and a liquid level sensor is fixedly connected to the top of the cooling chamber.
[0009] As a further optimization of this utility model, a nitrogen pipe is fixedly connected to one side of the nitrogen collection tank, a nitrogen delivery pipe connected to the feeding hopper is fixedly connected to one end of the nitrogen pipe, and a pressure sensor is fixedly connected to the top of the nitrogen pipe.
[0010] As a further optimization of this utility model, a grinding shaft is rotatably connected inside the feeding bin and the grinding bin. A servo motor for driving the grinding shaft to rotate is provided on one side of the feeding bin. A spiral push rod is fixedly sleeved on the outer surface of the grinding shaft inside the feeding bin, and a rod nail is fixedly sleeved on the outer surface of the grinding shaft inside the grinding bin.
[0011] As a further optimization of this utility model, the top of the liquid level sensor is electrically connected to a controller, the controller is electrically connected to a cryogenic liquid nitrogen pump, and the bottom of the liquid nitrogen storage tank is fixedly equipped with casters.
[0012] The beneficial effects of this invention are as follows: This invention rapidly delivers liquid nitrogen to the cooling chamber via a liquid nitrogen storage system, a cryogenic liquid nitrogen pump, and a cryogenic delivery pipeline. The extremely low boiling point of liquid nitrogen allows it to quickly absorb a large amount of heat, rapidly reducing the temperature of the grinding chamber within the cooling chamber to ultra-low temperatures. Specially designed guide strips inside the cooling chamber guide the liquid nitrogen to contact the grinding chamber evenly and efficiently, ensuring the uniformity and stability of the cooling effect. This enables highly efficient grinding of temperature-sensitive materials, significantly improving product qualification rates. The vaporized nitrogen is introduced into the grinding chamber through a pipeline. Within the grinding chamber, the nitrogen isolates oxygen and moisture, preventing material oxidation and hydrolysis. Simultaneously, the resulting airflow enhances grinding. The movement of the medium and materials improves grinding efficiency, shortens grinding time, and reduces the average particle size of the materials. In addition, the full utilization of nitrogen reduces liquid nitrogen consumption and energy loss, greatly reducing the overall energy consumption of the system. Then, a liquid level sensor is deployed in the sand mill to monitor the liquid nitrogen level in real time and is linked with the controller. When the liquid level is lower than the preset value, the liquid level sensor transmits a signal to the controller, which automatically controls the cryogenic liquid nitrogen pump to increase the liquid nitrogen delivery to ensure that there is enough liquid nitrogen in the cooling chamber for cooling. When the liquid level is higher than the safety value, the controller reduces or stops the liquid nitrogen delivery to avoid excessive liquid nitrogen causing waste and potential safety risks, and ensures stable and efficient operation in the cooling chamber. Attached Figure Description
[0013] Figure 1 This is a front view structural diagram of the present invention;
[0014] Figure 2This is a schematic diagram of the right-side structure of this utility model;
[0015] Figure 3 This is a schematic diagram of the right-side structure of the cooling chamber of this utility model;
[0016] Figure 4 This is a cross-sectional view of the present invention.
[0017] In the diagram: 1. Liquid nitrogen storage tank; 2. Cryogenic liquid delivery pipeline; 3. Cryogenic liquid nitrogen pump; 4. Guide bar; 5. Feeding bin; 6. Nitrogen collection tank; 7. Grinding chamber; 8. Controller; 9. Pressure sensor; 10. Safety valve; 11. Liquid level sensor; 12. Casters; 13. Servo motor; 14. Grinding shaft; 15. Discharge bin; 16. Liquid nitrogen inlet; 17. Feed inlet; 18. Cooling chamber; 19. Nitrogen delivery pipe; 20. Nitrogen pipe; 21. Collection pipe; 22. Spiral push rod; 23. Rod. Detailed Implementation
[0018] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.
[0019] Example 1
[0020] like Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, a cooling device for a sand mill includes a liquid nitrogen storage tank 1. The bottom of the liquid nitrogen storage tank 1 is fixedly equipped with casters 12. During use, the position of the liquid nitrogen storage tank 1 needs to be adjusted according to different production processes and site planning requirements. The casters 12 allow the liquid nitrogen storage tank 1 to be easily moved on the ground, shortening the distance to the sand mill and reducing losses during liquid nitrogen transportation. A cryogenic delivery pipeline 2 is fixedly connected to one side of the liquid nitrogen storage tank 1. During use, the cryogenic delivery pipeline 2 is suitable for cryogenic pressure vessels with temperatures ranging from -45℃ to -196℃, ensuring stable liquid nitrogen flow. A cooling chamber 18 is provided at one end of the cryogenic delivery pipeline 2, and a grinding chamber 7 is installed inside the cooling chamber 18. During use, the cooling chamber 18 is fitted over the outer surface of the grinding chamber 7. A cryogenic liquid nitrogen pump 3 is installed on the cryogenic delivery pipeline 2. During use, the cryogenic liquid nitrogen pump 3 can transport liquid nitrogen from a low-pressure location to a high-pressure location, reducing cold loss during transportation. A conveying device is fixedly connected to one side of the grinding chamber 7. The top of the feeding hopper 5 is fixedly connected to the inlet 17, and the side of the grinding hopper 7 is fixedly connected to the outlet hopper 15. During use, materials can be conveyed into the feeding hopper 5 through the inlet 17 for grinding. The grinding hopper 7 is connected to the outlet hopper 15, allowing the ground material to be discharged through the outlet hopper 15. The cooling hopper 18 contains guide strips 4 fixedly fitted onto the surface of the grinding hopper 7. During use, the guide strips 4 are spirally distributed, causing liquid nitrogen to flow across the surface of the grinding hopper 7, thereby improving the grinding performance of the grinding hopper 7. Cooling is achieved by rapidly vaporizing liquid nitrogen at a boiling point of -196°C under standard atmospheric pressure, which absorbs a large amount of heat and lowers the temperature to ultra-low temperatures. The surface of the cooling chamber 18 is provided with a liquid nitrogen port 16. One end of the cryogenic liquid delivery pipeline 2 is fixedly connected to the cooling chamber 18 through the liquid nitrogen port 16. In use, the liquid nitrogen port 16 on the surface of the cooling chamber 18 allows the liquid nitrogen flowing in the cryogenic liquid delivery pipeline 2 to be delivered into the interior of the cooling chamber 18, thereby cooling the grinding chamber 7 inside the cooling chamber 18.
[0021] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, a grinding shaft 14 is rotatably connected inside the feeding bin 5 and the grinding bin 7. A servo motor 13 is provided on one side of the feeding bin 5 to drive the grinding shaft 14 to rotate. A spiral push rod 22 is fixedly sleeved on the outer surface of the grinding shaft 14 inside the feeding bin 5. A rod 23 is fixedly sleeved on the outer surface of the grinding shaft 14 inside the grinding bin 7. In use, the grinding shaft 14 in the feeding bin 5 and the grinding bin 7 is driven to rotate by the servo motor 13. The spiral push rod 22 in the feeding bin 5 can push the material to move into the grinding bin 7. The rod 23 in the grinding bin 7 applies shearing, impact and other forces to the material during rotation, realizing continuous processing of the material from conveying to grinding.
[0022] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the top of the cooling chamber 18 is fixedly connected to several collection pipes 21, and the top of the collection pipes 21 is fixedly connected to a nitrogen collection tank 6. During use, liquid nitrogen vaporizes into nitrogen gas upon contact with air. The nitrogen gas flows through the collection pipes 21 into the nitrogen collection tank 6, thereby collecting the vaporized nitrogen. A safety valve 10 is installed on one side of the nitrogen collection tank 6. During use, the safety valve 10 automatically opens to release pressure when the pressure inside the nitrogen collection tank 6 exceeds a set safety value, preventing the tank from exploding due to excessive pressure and ensuring the safety of equipment and personnel. It automatically closes after the pressure returns to normal to maintain stable pressure inside the tank. The top of the cooling chamber 18 is fixedly connected to a liquid level sensor 11, and the top of the liquid level sensor 11 is electrically connected to a controller 8. The controller 8 is electrically connected to the cryogenic liquid nitrogen pump 3. During use, the liquid level sensor 11 monitors the liquid nitrogen level in real time. When the liquid level is lower than the preset value, the liquid level sensor 11 transmits a signal to the controller 8. The controller 8 automatically controls the cryogenic liquid nitrogen pump 3 to increase the liquid nitrogen delivery volume to ensure sufficient liquid nitrogen for cooling in the cooling chamber. When the liquid level is higher than the safety value, the controller 8 reduces or stops the liquid nitrogen delivery. A nitrogen pipe 20 is fixedly connected to one side of the nitrogen collection tank 6, and a nitrogen delivery pipe 19 connected to the feeding bin 5 is fixedly connected to one end of the nitrogen pipe 20. In use, the nitrogen stored in the nitrogen collection tank 6 is delivered into the feeding bin 5 through the nitrogen pipe 20 and the nitrogen delivery pipe 19. Since the feeding bin 5 is connected to the grinding bin 7, the nitrogen will also flow into the grinding bin 7. Through the replacement with air, the grinding bin 7 and the feeding bin 5 are in an inert atmosphere, thereby inhibiting the oxidation of the material. A pressure sensor 9 is fixedly connected to the top of the nitrogen pipe 20. In use, the pressure sensor 9 can monitor the pressure value in the nitrogen collection tank 6 in real time, so that the operator can keep track of the pressure status in the pipe in real time and ensure the safe and stable operation of the nitrogen delivery system.
[0023] It should be noted that, in operation, the cooling device of this sand mill works by feeding the sand material into the feeding bin 5 through the feed inlet 17, then starting the servo motor 13, which drives the grinding shaft 14 to rotate. The spiral pusher 22 on the grinding shaft 14 continuously pushes the sand material into the grinding bin 7, where it is ground by the rods 23 located inside the grinding bin 7. The heat generated by the rotating sand mill is distributed throughout the grinding bin 7. Then, the liquid nitrogen storage tank 1 is opened, allowing liquid nitrogen to enter the cooling bin 18 through the cryogenic delivery pipe 2 and the liquid nitrogen port 16 on the grinding bin 7. Because the guide strips 4 inside the cooling bin 18 are spirally distributed, the liquid nitrogen flows spirally along the outer wall of the grinding bin 7, extending the heat exchange time and ensuring uniform heat absorption and cooling, causing the temperature of the grinding bin 7 to drop rapidly. As the liquid nitrogen continuously cools the grinding bin 7, the liquid nitrogen... When the liquid level is below the preset value, the liquid level sensor 11 transmits a signal to the controller 8. The controller 8 automatically controls the cryogenic liquid nitrogen pump 3 to continue increasing the liquid nitrogen delivery volume of the liquid nitrogen storage tank 1. When the liquid level is above the safety value, the controller 8 controls the cryogenic liquid nitrogen pump 3 to reduce or stop the liquid nitrogen delivery. Since the liquid nitrogen in the cooling chamber 18 vaporizes into nitrogen gas after contacting the air, the nitrogen gas enters the nitrogen collection tank 6 through the collection pipe 21. The nitrogen gas flows through the nitrogen pipe 20 to the nitrogen delivery pipe 19 and is delivered into the grinding chamber 7 through the nitrogen delivery pipe 19. Since nitrogen gas is an inert gas, it replaces the air inside the grinding chamber 7, making the grinding chamber 7 have an inert atmosphere, which can inhibit the oxidation of the material being ground and protect the material being ground. Then, the ground material is delivered out through the discharge chamber 15, and the qualified material enters the subsequent process.
[0024] The embodiments described above are merely examples of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.
Claims
1. A cooling device for a sand mill, comprising a liquid nitrogen storage tank (1), characterized in that, A cryogenic liquid delivery pipeline (2) is fixedly connected to one side of the liquid nitrogen storage tank (1). A cooling chamber (18) is provided at one end of the cryogenic liquid delivery pipeline (2). A grinding chamber (7) is provided inside the cooling chamber (18). A cryogenic liquid nitrogen pump (3) is provided on the cryogenic liquid delivery pipeline (2). A feeding chamber (5) is fixedly connected to one side of the grinding chamber (7). An inlet (17) is fixedly connected to the top of the feeding chamber (5). A discharge chamber (15) is fixedly connected to one side of the grinding chamber (7).
2. The cooling device for a sand mill according to claim 1, characterized in that: The cooling chamber (18) has a guide strip (4) fixedly fitted to the surface of the grinding chamber (7). The surface of the cooling chamber (18) is provided with a liquid nitrogen port (16). One end of the cryogenic liquid delivery pipe (2) is fixedly connected to the cooling chamber (18) through the liquid nitrogen port (16).
3. The cooling device for a sand mill according to claim 1, characterized in that: The top of the cooling chamber (18) is fixedly connected to a plurality of collection pipes (21), the top of the plurality of collection pipes (21) is fixedly connected to a nitrogen collection tank (6), a safety valve (10) is provided on one side of the nitrogen collection tank (6), and a liquid level sensor (11) is fixedly connected to the top of the cooling chamber (18).
4. The cooling device for a sand mill according to claim 3, characterized in that: A nitrogen pipe (20) is fixedly connected to one side of the nitrogen collection tank (6), and a nitrogen delivery pipe (19) connected to the feeding bin (5) is fixedly connected to one end of the nitrogen pipe (20). A pressure sensor (9) is fixedly connected to the top of the nitrogen pipe (20).
5. The cooling device for a sand mill according to claim 1, characterized in that: The feeding bin (5) and the grinding bin (7) are rotatably connected to a grinding shaft (14). A servo motor (13) for driving the grinding shaft (14) to rotate is provided on one side of the feeding bin (5). A spiral push rod (22) is fixedly sleeved on the outer surface of the grinding shaft (14) inside the feeding bin (5). A rod nail (23) is fixedly sleeved on the outer surface of the grinding shaft (14) inside the grinding bin (7).
6. The cooling device for a sand mill according to claim 3, characterized in that: The top of the liquid level sensor (11) is electrically connected to a controller (8), which is electrically connected to a cryogenic liquid nitrogen pump (3). The bottom of the liquid nitrogen storage tank (1) is fixedly equipped with casters (12).