Liquid nitrogen flow control pump

Abstract

This utility model discloses a liquid nitrogen flow control pump, including a main body with a flow channel formed inside. A liquid guide pipe is connected to the inlet end of the flow channel. A heating rod for vaporizing liquid nitrogen in a liquid nitrogen tank is installed on the outer side of the inlet end of the liquid guide pipe. The increased gas density in the liquid nitrogen tank achieves pressurization, allowing liquid nitrogen to enter from the inlet end of the liquid guide pipe and reach the outlet after passing through the flow channel. A stepper motor is also installed on the main body, with a plug fixed to its output end. The plug is adjusted up and down by the stepper motor, extending downwards from the upper side of the main body into the flow channel. Moving the plug adjusts the size of the flow channel, thereby regulating the flow rate of liquid nitrogen. A sealing main pipe is fixed to the lower side of the main body, with a polytetrafluoroethylene (PTFE) tube connected to its lower side. A threaded locking clamp, a sealing ring, a limiting ring, and a fixing ring are fitted and fixed to the outer side of the sealing main pipe. A PTFE isolation element is also fixed to the lower side of the PTFE tube, and the PTFE isolation element has several through holes.

Description

Technical Field

[0001] This utility model relates to the technical field of liquid nitrogen delivery equipment, and in particular to a liquid nitrogen flow control pump. Background Technology

[0002] In modern industrial production and scientific research, liquid nitrogen, due to its ultra-low temperature properties, is widely used in many fields such as food freezing and preservation, metal material processing, medical surgical refrigeration, semiconductor manufacturing, and low-temperature physics research. In these applications, precise and stable control of liquid nitrogen flow rate is crucial. Precise liquid nitrogen flow rate control not only ensures the stability of the process and product quality but also effectively reduces liquid nitrogen waste and saves production costs.

[0003] However, existing liquid nitrogen flow control methods suffer from numerous technical bottlenecks. On the one hand, traditional liquid nitrogen flow control devices often employ simple manual valve adjustment or ordinary electric valve control, making it difficult to achieve precise regulation of liquid nitrogen flow. Because liquid nitrogen is susceptible to vaporization due to temperature changes during transport, leading to pressure fluctuations within the pipeline, manual adjustment methods are slow to respond and cannot adapt to pressure changes in a timely manner, making it difficult to guarantee flow stability. Ordinary electric valves have limited control precision and cannot meet the demands for high-precision liquid nitrogen flow control. In applications requiring high flow accuracy, such as the cooling process in semiconductor chip manufacturing, inaccurate flow control can easily affect product yield.

[0004] Precise flow control of liquid nitrogen is widely used in industrial production and scientific research, but existing liquid nitrogen flow control equipment suffers from numerous technical bottlenecks. In traditional flow control devices, the cryogenic isolation between the liquid nitrogen delivery pipeline and the external environment is inadequate, easily leading to vaporization of the liquid nitrogen during transport due to heat absorption from the surrounding environment. This causes pressure fluctuations within the pipeline, affecting flow control accuracy, and vaporization also increases liquid nitrogen loss. Furthermore, existing equipment lacks precise monitoring of liquid nitrogen level and temperature, failing to provide reliable data support for flow control and hindering real-time dynamic adjustment of the liquid nitrogen flow rate. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a liquid nitrogen flow control pump, thereby solving the above-mentioned defects.

[0006] The objective of this utility model is achieved through the following technical solution:

[0007] A liquid nitrogen flow control pump, comprising:

[0008] The main body has an internal flow channel. A liquid guide pipe is connected to the inlet end of the flow channel. A heating rod for vaporizing liquid nitrogen in a liquid nitrogen tank is installed on the outside of the inlet end of the liquid guide pipe. This increases the gas density in the liquid nitrogen tank, creating pressure that allows liquid nitrogen to enter from the inlet end of the liquid guide pipe, pass through the flow channel, and reach the outlet. A stepper motor is also installed on the main body. A plug is fixed to the output end of the stepper motor. The plug is adjusted up and down by the stepper motor. The plug extends downwards from the upper side of the main body into the flow channel. By moving the plug, the size of the flow channel is adjusted, thereby regulating the flow rate of liquid nitrogen.

[0009] A sealing main tube is fixed to the lower side of the main body, and a polytetrafluoroethylene (PTFE) tube is connected to the lower side of the sealing main tube. A threaded locking clamp, a sealing rubber ring, a limiting ring, and a fixing ring are also fitted and fixed on the outer side of the sealing main tube. A PTFE isolation component is also fixed to the lower side of the PTFE tube, and several through holes are opened on the PTFE isolation component.

[0010] In one or more embodiments of this utility model, the main body is further fixed with a grid head, a pagoda head, a photoelectric switch and an exhaust valve, and a terminal block is covered and fixed on the main body. The terminal block has a cavity inside, and the grid head, pagoda head, photoelectric switch, exhaust valve and stepper motor are located in the cavity. An LCD screen is also provided on the terminal block.

[0011] In one or more embodiments of this utility model, the inlet end of the flow channel is located on the lower side of the main body, the outlet end of the flow channel is located on the side of the main body, and a safety valve is also installed on the other side of the main body.

[0012] In one or more embodiments of this utility model, a power connector and a connector are fixed on the outside of the terminal block, and the power connector is electrically connected to the stepper motor.

[0013] In one or more embodiments of this utility model, the liquid guide tube is located inside the sealing main tube, the polytetrafluoroethylene (PTFE) tube, and the PTFE isolation element; a liquid level rod is also provided on the side of the liquid guide tube, and the liquid guide tube and the liquid level rod are fixed by a fixing element; the lower end of the liquid level rod extends into the PTFE isolation element, and the upper end of the liquid level rod is located inside the PTFE tube.

[0014] In one or more embodiments of this utility model, a temperature probe is also provided inside the polytetrafluoroethylene insulating component.

[0015] In one or more embodiments of this utility model, the polytetrafluoroethylene (PTFE) insulating element is generally cylindrical in shape. A cylindrical groove is formed on the outer side of the upper end of the PTFE insulating element, and the lower end of the PTFE tube is located on the cylindrical groove. A first cylindrical groove and a second cylindrical groove are formed on the upper side of the PTFE insulating element, and the lower ends of the liquid level rod and the liquid guide tube are respectively adapted to the first cylindrical groove and the second cylindrical groove. A third cylindrical groove is formed on the lower side of the PTFE insulating element, and the heating rod is disposed in the third cylindrical groove. The through hole is connected to the second cylindrical groove.

[0016] The beneficial effects of this utility model are:

[0017] This liquid nitrogen flow control pump, through innovative design and multi-component collaborative operation, demonstrates significant advantages in flow control, safety protection, structural performance, and functional integration, effectively meeting the precise control requirements of liquid nitrogen in industrial production and scientific research experiments. In terms of precise flow control, a stepper motor drives a PEEK plug to precisely adjust the flow channel size. Combined with high-precision control logic, it enables fine-tuning of liquid nitrogen flow, meeting stringent flow accuracy requirements in various scenarios. Whether it's the minute-by-minute precise control of coolant flow in semiconductor manufacturing or the large-flow stable output in food freezing, this pump can accurately adapt, effectively avoiding product quality issues caused by flow fluctuations and improving production process stability. A safety valve monitors the flow channel pressure in real time, automatically releasing pressure in case of overpressure to prevent pipe rupture. The sealing main pipe, together with threaded locking clamps, sealing rings, and other components, forms a reliable sealing structure, eliminating the risk of liquid nitrogen leakage. Temperature... The probe monitors the liquid nitrogen temperature in real time, and the liquid level gauge indicates the liquid nitrogen level. Combined with the control system, it can provide early warnings of abnormal situations, comprehensively ensuring the safety of equipment operation and personnel. The internal flow channels are scientifically laid out, and the external terminals integrate multiple functional components, reducing space occupation. All components are securely connected with excellent sealing performance, adapting to complex industrial environments, reducing maintenance frequency, and extending equipment lifespan. The PTFE isolation element is made of PTFE material, which has excellent low-temperature resistance and thermal insulation properties, reducing the impact of external heat on liquid nitrogen, lowering the liquid nitrogen vaporization rate, and stabilizing the pressure inside the pipeline. Its through-hole connects to the second cylindrical groove, which can evenly disperse liquid nitrogen and ensure the stability of liquid nitrogen flow. In addition, the temperature probe installed in the PTFE isolation element can monitor the liquid nitrogen temperature in real time, and the liquid level gauge can accurately detect the liquid nitrogen level, providing accurate data for flow control and enabling precise adjustment and dynamic management of liquid nitrogen flow. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model;

[0019] Figure 2 This is a schematic diagram of the structure after removing the PTFE tube, terminal, and PTFE insulating component;

[0020] Figure 3 This is a cross-sectional view of the present invention;

[0021] Figure 4 This is a structural diagram of the main body and the plug;

[0022] Figure 5 yes Figure 3 Enlarged view of point A in the image. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this utility model provided in the accompanying drawings is not intended to limit the scope of the claimed utility model, but merely represents selected embodiments of the utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0024] In this embodiment, as Figures 1 to 5 As shown, a liquid nitrogen flow control pump mainly consists of a main body, a liquid guide pipe, a heating rod, a stepper motor, a plug, and other auxiliary components, which can achieve precise control of liquid nitrogen flow rate.

[0025] The main body 22 of the liquid nitrogen control pump is made of high-strength, corrosion-resistant material, with an internal flow channel forming the core channel for liquid nitrogen transfer. The inlet end of the flow channel is located on the lower side of the main body 22 and is connected to a liquid guide pipe 19. A heating rod 21 is wound around the outside of the inlet end of the liquid guide pipe 19. When the heating rod 21 is energized, it heats the liquid nitrogen near the outlet of the liquid nitrogen tank, causing the liquid nitrogen to vaporize rapidly, increasing the gas density inside the liquid nitrogen tank, and achieving a pressurization effect. Under pressure, liquid nitrogen enters from the inlet end of the liquid guide pipe 19, flows along the flow channel, and finally flows out from the outlet end located on the side of the main body 22. A safety valve is also installed on the other side of the main body 22. When the pressure inside the flow channel exceeds a set threshold, the safety valve 3 automatically opens to release pressure, ensuring the safe operation of the equipment.

[0026] A stepper motor 15 is fixedly mounted on the main body 22, with its output end pointing vertically downwards and fixedly connected to the plug 23. The plug 23 is made of PEEK material, which has excellent low-temperature resistance and corrosion resistance. The plug 23 extends downwards from the upper side of the main body 22 into the flow channel. By controlling the rotation of the stepper motor 15, the vertical position of the plug 23 within the flow channel can be precisely adjusted. When the plug 23 moves downwards, the flow area of ​​the flow channel decreases, and the liquid nitrogen flow rate decreases; conversely, when the plug 23 moves upwards, the flow area of ​​the flow channel increases, and the liquid nitrogen flow rate increases, thereby achieving precise control of the liquid nitrogen flow rate.

[0027] The main body 22 also integrates various functional components, including a grid connector 12, a pagoda connector 13, a photoelectric switch 14, and an exhaust valve 16. A terminal block 2, made of 6061 aluminum alloy, is fixedly mounted on the main body 22. The terminal block 2 has an internal cavity, within which the grid connector 12, pagoda connector 13, photoelectric switch 14, exhaust valve 16, and stepper motor 15 are all installed, effectively protecting the internal components and making the structure more compact. An LCD screen 1 is installed on the terminal block 2 to display the operating parameters, flow setpoint, and real-time flow of the liquid nitrogen flow control pump, allowing operators to intuitively monitor the equipment's operating status. The grid connector 12 is M12, and the pagoda connector 13 is M5, used for sealing and fixing cables and connecting pipes, respectively. Power connectors 4 and 5 are fixed to the outside of terminal 2. Power connector 4 is a 24V power connector, which is electrically connected to stepper motor 15 to provide it with a stable power supply. Connector 5 is a 485 / 4-20MA connector, used to realize data communication between the device and an external control system, facilitating remote control and parameter adjustment. The photoelectric switch 14 is located on the upper side of stepper motor 15.

[0028] A sealing main pipe 18 is fixedly installed on the lower side of the main body 22, and a polytetrafluoroethylene (PTFE) tube 10 is connected to the lower side of the sealing main pipe 18. A threaded locking clamp 6, a sealing rubber ring 7, a limiting ring 8, and a fixing ring 9 are sequentially fitted and fixed on the outer side of the sealing main pipe 18. Through the tightening action of the threaded locking clamp 6 and the sealing rubber ring 7, a reliable seal is achieved between the sealing main pipe 18 and the PTFE tube 10, preventing liquid nitrogen leakage. A PTFE spacer 11 is fixed to the lower side of the PTFE tube 10. The PTFE spacer 11 has several through holes for the flow and dispersion of liquid nitrogen. A liquid guide pipe 19 passes through the sealing main pipe 18, the PTFE tube 10, and the PTFE spacer 11. A liquid level rod 17 is provided beside the liquid guide pipe 19, and the liquid guide pipe 19 and the liquid level rod 17 are fixed by a fixing member 20. The lower end of the liquid level rod 17 extends into the PTFE isolator 11 to detect the liquid nitrogen level; the upper end is located inside the PTFE tube 10 and connects to an external liquid level detection system. In addition, a TP100A-grade temperature probe 24 is installed inside the PTFE isolator 11 to monitor the liquid nitrogen temperature in real time, providing data support for equipment operation control and safety early warning.

[0029] In one or more embodiments of this utility model, the polytetrafluoroethylene (PTFE) insulating member 11 is generally cylindrical in shape. A cylindrical groove is formed on the outer side of the upper end of the PTFE insulating member 11, and the lower end of the PTFE tube 10 is located on the cylindrical groove. A first cylindrical groove and a second cylindrical groove are formed on the upper side of the PTFE insulating member 11, and the lower ends of the liquid level rod 17 and the liquid guide tube 19 are respectively adapted to the first cylindrical groove and the second cylindrical groove. A third cylindrical groove is formed on the lower side of the PTFE insulating member 11, and the heating rod 21 is disposed in the third cylindrical groove. The through hole is connected to the second cylindrical groove.

[0030] In another embodiment, regarding the connection between the main body 22 and the various components, the terminal block 2 and the main body 22 are fixed together using a mortise and tenon structure with bolts. Compared to the simple cover-and-fit fixation in Embodiment 1, the connection is more robust and easier to disassemble and maintain. The connection between the sealing main pipe 18 and the main body 22 is achieved by welding, which enhances the sealing performance and strength of the connection.

[0031] For the plug 23, while maintaining the properties of the PEEK material, its shape and contour have been optimized with a streamlined structure to further reduce resistance during liquid nitrogen flow and improve the sensitivity and accuracy of flow control. The stepper motor 15 has been upgraded to a high-precision microstepping stepper motor, which can achieve precise rotation at smaller angles, thereby allowing for more precise adjustment of the position of the plug 23 and further improving the accuracy of liquid nitrogen flow control.

[0032] Regarding auxiliary components, both the Grammad head 12 and the pagoda head 13 are made of stainless steel to enhance corrosion resistance and mechanical strength. The liquid level rod 17 uses a laser liquid level sensor, which has higher detection accuracy and faster response speed compared to the traditional liquid level detection method in Example 1. The temperature probe 24 has been replaced with a high-precision model with self-calibration function, which can automatically correct measurement errors and ensure the accuracy and reliability of temperature detection data. Figure 5 The arrows in the diagram illustrate the direction of the liquid nitrogen.

[0033] Working principle of this utility model:

[0034] First, the PTFE isolator 11 end of the flow control pump is placed inside the liquid nitrogen tank. The heating rod 21 is then activated to heat and pressurize the liquid nitrogen at the outlet of the liquid nitrogen tank, causing the liquid nitrogen to flow into the guide pipe 19 and enter the flow channel of the main body 22. The operator sets the required liquid nitrogen flow rate value through the LCD screen 1. The control system drives the stepper motor 15 to rotate according to the set value, adjusting the position of the plug 23 in the flow channel to precisely control the liquid nitrogen flow rate. The liquid level rod 17 monitors the liquid nitrogen level in real time, and the temperature probe 24 detects the liquid nitrogen temperature in real time. The relevant data is transmitted to the external control system through the connector 5 so that the operator can keep track of the equipment's operating status. When the pressure in the flow channel is abnormal, the safety valve 3 automatically opens to release pressure, ensuring the safe and stable operation of the equipment.

[0035] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "left," and "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, terms such as "set" and "connect" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

Claims

1. A liquid nitrogen controlled-flow pump, characterized in that, include: The main body (22) has a flow channel inside. The inlet end of the flow channel is connected to a liquid guide pipe (19). A heating rod (21) for vaporizing liquid nitrogen in the liquid nitrogen tank is provided on the outside of the inlet end of the liquid guide pipe (19). The gas density in the liquid nitrogen tank is increased to achieve pressurization, so that liquid nitrogen enters from the inlet end of the liquid guide pipe (19) and reaches the outlet after passing through the flow channel. The main body (22) is also provided with a stepper motor (15). A plug (23) is fixed at the output end of the stepper motor (15). The plug (23) is adjusted up and down by the stepper motor (15). The plug (23) extends downward from the upper side of the main body (22) into the flow channel. The size of the flow channel is adjusted by moving the plug (23), thereby adjusting the flow rate of liquid nitrogen. A sealing main tube (18) is fixed on the lower side of the main body (22), and a polytetrafluoroethylene tube (10) is connected to the lower side of the sealing main tube (18). A threaded pull lock clamp (6), a sealing rubber ring (7), a limiting ring (8) and a fixing ring (9) are also fitted and fixed on the outer side of the sealing main tube (18). A polytetrafluoroethylene isolation piece (11) is also fixed on the lower side of the polytetrafluoroethylene tube (10), and several through holes are opened on the polytetrafluoroethylene isolation piece (11).

2. The liquid nitrogen flow control pump according to claim 1, characterized in that: The main body (22) is also fixed with a granite head (12), a pagoda head (13), a photoelectric switch (14) and an exhaust valve (16). A terminal block (2) is covered and fixed on the main body (22). The terminal block (2) has a cavity inside. The granite head (12), the pagoda head (13), the photoelectric switch (14), the exhaust valve (16) and the stepper motor (15) are located in the cavity. An LCD screen (1) is also provided on the terminal block (2).

3. The liquid nitrogen flow control pump according to claim 1, characterized in that: The inlet end of the flow channel is located on the lower side of the main body (22), the outlet end of the flow channel is located on the side of the main body (22), and a safety valve (3) is also installed on the other side of the main body (22).

4. A liquid nitrogen flow control pump according to claim 2, characterized in that: The power connector (4) and connector (5) are fixed on the outside of the terminal block (2), and the power connector (4) is electrically connected to the stepper motor (15).

5. A liquid nitrogen flow control pump according to claim 1, characterized in that: The liquid guide tube (19) is located inside the sealing main tube (18), the polytetrafluoroethylene tube (10), and the polytetrafluoroethylene isolation element (11); a liquid level rod (17) is also provided on the side of the liquid guide tube (19), and the liquid guide tube (19) and the liquid level rod (17) are fixed by a fixing element (20); the lower end of the liquid level rod (17) extends into the polytetrafluoroethylene isolation element (11), and the upper end of the liquid level rod (17) is located inside the polytetrafluoroethylene tube (10).

6. A liquid nitrogen flow control pump according to claim 1, characterized in that: A temperature probe (24) is also installed inside the polytetrafluoroethylene isolation element (11).

7. A liquid nitrogen flow control pump according to claim 5, characterized in that: The polytetrafluoroethylene (PTFE) isolation element (11) is cylindrical in shape. A cylindrical groove is provided on the outer side of the upper end of the PTFE isolation element (11), and the lower end of the PTFE tube (10) is located on the cylindrical groove. A first cylindrical groove and a second cylindrical groove are provided on the upper side of the PTFE isolation element (11). The lower ends of the liquid level rod (17) and the liquid guide tube (19) are respectively adapted to the first cylindrical groove and the second cylindrical groove. A third cylindrical groove is provided on the lower side of the PTFE isolation element (11), and the heating rod (21) is disposed in the third cylindrical groove. The through hole is connected to the second cylindrical groove.

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