Self-adaptive pressure control method and system for double-spindle nail disc mill sealing system

Abstract

The invention discloses a self-adaptive pressure control method for a double-spindle nail disc mill sealing system. The self-adaptive pressure control method comprises the following steps that the internal pressure P0 of a cavity, the regional pressure P1 between a second-stage sealing unit and a third-stage sealing unit on one side of a spindle and the regional pressure P2 between the second-stage sealing unit and the third-stage sealing unit on the two sides of the spindle are monitored in real time; the pressure difference value P10 of one side of the main shaft is calculated according to the formula P10 = P1-P0, and the pressure difference value P20 of the two sides of the main shaft is calculated according to the formula P20 = P2-P0; and comparing the pressure difference value P10 with a preset first difference value threshold value, comparing the pressure difference value P20 with a second difference value threshold value, and adaptively adjusting the air inlet pressure of the second-stage sealing unit and the air inlet pressure of the third-stage sealing unit according to the comparison result, so that the pressure difference value P10 and the pressure difference value P20 are maintained in respective preset threshold value ranges. The pressure of key points of the cavity and the sealing system is monitored in real time, the air pressure of each stage of sealing unit is dynamically adjusted based on the pressure difference value, self-adaptive matching of the sealing pressure to the working condition of the cavity is achieved, and the industrial problem that leakage and excessive abrasion / high energy consumption of traditional fixed pressure sealing under the dynamic working condition cannot be considered at the same time is solved.

Description

Technical Field

[0001] This invention relates to the field of powder processing technology, and in particular to an adaptive pressure control method and system for a dual-spindle nail disc mill sealing system. Background Technology

[0002] The dual-spindle pin-disc mill is a core piece of equipment for ultrafine grinding and surface modification of materials in fields such as new energy, pharmaceuticals, and fine chemicals. Its spindle sealing system faces extremely harsh operating conditions: the chamber is filled with highly permeable ultrafine powder, maintaining a high-pressure, high-temperature environment; simultaneously, the two spindles rotate at high speed relative to each other, accompanied by dynamic oscillation. Under these conditions, the sealing performance directly determines the equipment's operational reliability, material yield, and production costs.

[0003] Currently, the mainstream sealing solution in this field adopts a fixed pressure approach, which involves constantly supplying clean gas at a preset pressure to the gas-tight sealing unit. This approach has inherent drawbacks: when the chamber pressure increases due to changes in feed, material characteristics, or process, insufficient fixed sealing pressure can lead to severe powder leakage, resulting in material waste and environmental pollution; conversely, when the chamber pressure decreases, excessively high sealing pressure can exacerbate friction between the seal and the spindle, leading to abnormally high energy consumption and accelerated component wear, creating a vicious cycle of leakage and excessive wear.

[0004] Furthermore, existing technologies lack effective pressure monitoring and feedback mechanisms, failing to provide early warnings for abnormal conditions such as sudden increases in chamber pressure and seal failure. This not only makes the stability of the sealing effect highly dependent on operator experience but also introduces serious safety hazards such as equipment overload and spindle jamming. Therefore, developing a sealing pressure control method that can dynamically adapt to changes in operating conditions and achieve intelligent regulation and early warning has become an urgent need in the industry. Summary of the Invention

[0005] The purpose of this invention is to provide an adaptive pressure control method and system for a dual-spindle nail disc grinding sealing system. By monitoring the pressure of the chamber and key points of the sealing system in real time, and dynamically adjusting the air pressure of each sealing unit based on the pressure difference, the sealing pressure is adaptively matched to the working conditions of the chamber. This solves the industry problem that traditional fixed pressure seals cannot simultaneously address leakage and excessive wear / high energy consumption under dynamic working conditions.

[0006] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention discloses an adaptive pressure control method for a dual-spindle nail disc mill sealing system. The dual-spindle nail disc mill includes a coaxially rotating feed-side spindle one and a non-feed-side spindle two, a mill disc arranged around the connection between the feed-side spindle one and the non-feed-side, and a chamber connected to the mill disc. A sealing structure is provided at the connection between the mill disc and the chamber. Along the centerline of the mill disc, the sealing structure includes a first-stage sealing unit, a second-stage sealing unit, and a third-stage sealing unit in sequence from the end away from the chamber to the end close to the chamber. The first-stage sealing unit is a contact mechanical seal, and the second-stage sealing unit and the third-stage sealing unit are non-contact air curtain seals. The control method includes the following steps: S1, Real-time monitoring of the internal pressure P0 of the chamber, the regional pressure P1 between the second-stage sealing unit and the third-stage sealing unit on one side of the main shaft, and the regional pressure P2 between the second-stage sealing unit and the third-stage sealing unit on both sides of the main shaft; S2. Calculate the pressure difference ΔP on one side of the main shaft. 10 = P1 - P0, and the pressure difference ΔP on both sides of the main shaft. 20 = P2 - P0; S3, the pressure difference ΔP 10 Compare with the preset first difference threshold, △P 20 The pressure difference ΔP is compared with a second difference threshold, and based on the comparison result, the intake pressure of the second-stage sealing unit and the third-stage sealing unit is adaptively adjusted to make the pressure difference ΔP... 10 and △P 20 They remain within their respective preset threshold ranges.

[0007] A further solution: The adaptive adjustment specifically includes: When △P 10 Below the first difference threshold lower limit △P 100 At that time, the intake pressure of the second-stage and third-stage sealing units on one side of the control spindle is adjusted upwards, and the adjustment range is related to (△P). 100 - △P 10 The values ​​of ) are positively correlated; When △P 10 The difference is higher than the upper limit of the first difference threshold △P 101 At that time, the intake pressure of the second-stage and third-stage sealing units on one side of the control spindle is adjusted downwards, and the adjustment range is related to (△P). 10 - △P 101 The values ​​of ) are positively correlated; When △P 20 Below the second difference threshold lower limit △P 200 At that time, the intake pressure of the second-stage and third-stage sealing units on both sides of the control spindle is adjusted upward, and the adjustment range is related to (△P). 200- △P 20 The values ​​of ) are positively correlated; When △P 20 Higher than the upper limit of the second difference threshold △P 201 At that time, the intake pressure of the second-stage and third-stage sealing units on both sides of the control spindle is adjusted downward, and the adjustment range is related to (△P). 20 - △P 201 The values ​​of ) are positively correlated.

[0008] A further solution: The control method also includes an independent adjustment step for the third-stage sealing unit on one side of the spindle. Based on the comparison between P1 and the first difference threshold, the pressure of the third-stage sealing unit is further optimized: When P1 < P 100 At that time, the intake pressure of the third-stage sealing unit is reduced, the magnitude of which is the same as (P). 100 -P1) shows a positive correlation; When P1 > P 101 At that time, the intake pressure of the third-stage sealing unit is increased, and the magnitude is the same as (P1-P). 101 ) are positively correlated; Furthermore, the intake pressure of the second-stage sealing unit is always kept higher than that of the third-stage sealing unit on the same side.

[0009] A further solution: The control method also includes independent adjustment steps for the third-stage sealing units on both sides of the spindle. Based on the comparison between P2 and the second difference threshold, the pressure of the third-stage sealing unit is further optimized: When P2 < P 200 At that time, the intake pressure of the third-stage sealing unit is reduced, the magnitude of which is the same as (P). 20-0 -P2) showed a positive correlation; When P2 > P 201 At that time, the intake pressure of the third-stage sealing unit is increased, by the same amount as (P2-P). 20-1 ) are positively correlated.

[0010] Further solution: In step S1, the leakage pressure P3 of the first-stage sealing unit on one side of the spindle and the leakage pressure P4 of the first-stage sealing unit on both sides of the spindle are also monitored in real time. The control method further includes a leakage early warning step S4: When P3 exceeds the preset leakage threshold P 30 At that time, a warning signal indicating the failure of the first-stage sealing unit on one side of the spindle is generated; When P4 exceeds the preset leakage threshold P 40 At that time, a warning signal is generated indicating that the first-stage sealing unit on the second (2) side of the main shaft has failed.

[0011] Further solution: Set the initial target pressure value of each sealing unit, i.e. the reference pressure value; then the preset reference pressure value of the second-stage sealing unit and the third-stage sealing unit on the main shaft one (1) side is higher than the preset reference pressure value of the corresponding sealing unit on the main shaft two (2) side.

[0012] A further proposed solution is to set the lower limit of the first pressure difference threshold higher than the upper limit of the first pressure difference threshold.

[0013] Secondly, this invention discloses an adaptive pressure control system for a dual-spindle nail disc mill multi-stage sealing system, used to execute the above-mentioned control method, the system comprising: Central controller; Multiple pressure sensors are installed inside the grinding chamber, between the second-stage sealing unit and the third-stage sealing unit on one side of the spindle, and between the second-stage sealing unit and the third-stage sealing unit on both sides of the spindle, for real-time acquisition of pressure data and transmission to the central controller; The pressure regulating component is connected to the air inlet of each of the secondary and tertiary sealing units and is controlled by the central controller to regulate the air inlet pressure of each sealing unit.

[0014] Compared with the prior art, the beneficial effects of the present invention are: This invention provides an adaptive pressure control method for a multi-stage sealing system of a dual-spindle nail disc mill. Its core technological advantage lies in upgrading the sealing system from a static, passive "barrier" to a dynamic, intelligent "adjustment system." This method uses a network of pressure sensors deployed within the chamber and sealing channels to capture the system status in real time. Based on this data, it automatically and precisely adjusts the pressure of each stage of the air curtain seal, ensuring that the sealing gap is always maintained within the most effective pressure difference range.

[0015] Based on the above principles, this method achieves three major breakthroughs: First, it significantly improves sealing reliability by dynamically tracking changes in chamber pressure, thus completely avoiding powder leakage under high pressure and excessive wear under low pressure; second, it greatly reduces system energy consumption by achieving "on-demand gas supply," eliminating ineffective energy consumption under fixed pressure mode, and reducing spindle running resistance; third, it endows the equipment with intelligent early warning capabilities, enabling timely identification of primary seal failure and abnormal chamber pressure, preventing problems before they occur, and greatly improving the safety and maintainability of the equipment.

[0016] Furthermore, this solution boasts exceptional adaptability to various operating conditions. By pre-setting multiple sets of pressure reference parameters, it can switch to a sealing mode adapted to different material characteristics and process requirements with a single click, enabling a single device to flexibly handle diverse production tasks and achieving a balance between high efficiency, energy saving, and intelligence. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the structure of the grinding disc in this invention; Figure 3 This is a schematic diagram of the cavity structure in this invention; Figure 4 This is a side sectional view of the present invention; Figure 5 For the present invention and Figure 2 Side section view with cross-section perpendicular to each other; Figure 6 This is a cross-sectional view of the first rotating shaft support, grinding disc, and wear-resistant inner ring in this invention. Figure 7 This is a cross-sectional view of the second rotating shaft support, grinding disc, and outer spacer ring in this invention; Figure 8 This is a diagram showing the installation layout of the pressure sensor in this invention; In the diagram: 1-Main spindle one, 2-Main spindle two, 3-Grinding disc, 4-Cavity, 5-First rotating shaft support, 6-Second rotating shaft support, 7-Feed inlet, 8-First air inlet, 9-Second air inlet, 10-Skeleton oil seal, 11-Wear-resistant inner ring, 12-Outer spacer ring, 13-Pin, 14-End cap, 15-Drive one, 16-Drive two, 17-First pressure sensor, 18-Second pressure sensor, 19-Third pressure sensor, 20-Fourth pressure sensor, 21-Fifth pressure sensor. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "inner," and "outer," 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 in which the product of this invention is usually placed during use. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the device or element 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 invention.

[0020] Please see Figure 1-7 The structure of the dual-spindle nail disc mill and multi-stage sealing system is as follows: The system includes a coaxial, counter-rotating feed-side main shaft 1 and a non-feed-side main shaft 2; a grinding disc 3 annularly arranged at the connection between main shafts 1 and 2; and a chamber 4 connected to the grinding disc 3. The chamber 4 has an annular structure, with the grinding disc 3 located in the center. The powder ground by the grinding disc 3 is collected in the chamber 4. A sealing structure is provided at the connection between the grinding disc 3 and the chamber 4. Along the centerline of the grinding disc 3, the sealing structure sequentially includes a first-stage sealing unit, a second-stage sealing unit, and a third-stage sealing unit from the end furthest from the chamber 4 to the end closest to the chamber 4. The first-stage sealing unit is a contact mechanical seal, while the second and third-stage sealing units are non-contact air curtain seals. This sealing structure is arranged on both sides of main shafts 1 and 2, using an asymmetrical, differentiated configuration. Main shaft 1 is driven to rotate by drive 15, and main shaft 2 is driven to rotate by drive 16. Through a multi-stage series sealing structure of "contact-non-contact", multiple sealing defenses are constructed, laying a fundamental structural foundation for achieving both zero leakage and ultra-long service life.

[0021] Furthermore, the grinding disc 3 includes a grinding disc body, a first rotating shaft support 5 and a second rotating shaft support 6 respectively located at the two ends of the grinding disc body; wherein, the first rotating shaft support 5 is close to the main shaft 1, and the second rotating shaft support 6 is close to the main shaft 2. The grinding disc body has two disc-shaped, overlapping grinding pairs, one grinding pair is connected to the main shaft 1, and the other grinding pair is connected to the main shaft 2. The two grinding pairs are driven to rotate in opposite directions at high speed by the two main shafts. Pins 13 are provided on the opposite surfaces of the two grinding pairs. When rotating, the upper and lower pins 13 interlock and mesh with each other, forming a strong shearing, impact and grinding force field to achieve grinding.

[0022] Furthermore, a feed inlet 7 is integrated on the first rotary bearing seat support 5. The raw material enters the grinding disc 3 continuously and controllably through the feed inlet 7 for ultrafine grinding and dispersion.

[0023] Furthermore, taking the sealing structure on the main shaft 1 side as an example, the first-stage sealing unit includes symmetrically arranged skeleton oil seals 10. The inner ring of the skeleton oil seal 10 is interference-fitted with the main shaft 1, with an interference amount of 0.02mm to 0.05mm. The second-stage sealing unit includes a first air inlet 8 (III-1, III-2) radially opened on the bottom end face of the first rotating shaft support 5, and a wear-resistant inner ring 11 sleeved on the main shaft 1. The gap between the wear-resistant inner ring 11 and the main shaft 1 connects the first air inlet 8 to the chamber 4. The third sealing unit includes a second air inlet 9 (IV-1, IV-2) opened on the outer edge of the first rotating shaft support 5, and the second air inlet 9 is connected to the chamber 4. The inner ring of the oil seal is provided with a dustproof lip (double-lip structure) to further prevent residual trace powder from entering and enhance sealing reliability. Furthermore, the clean gas pressure introduced into the second-stage sealing unit is higher than the pressure in chamber 4, while the clean gas pressure introduced into the third-stage sealing unit is higher than the pressure in chamber 4 but lower than the gas pressure in the second-stage sealing unit. A precise pressure gradient (second-stage pressure > third-stage pressure > chamber pressure) is established to ensure that the mainstream airflow direction is towards the chamber, thereby effectively preventing powder escape and creating conditions for the coordinated operation of non-contact and contact seals.

[0024] Furthermore, the airflow direction of the second-stage sealing unit and the third-stage sealing unit is configured to flow towards chamber 4. By configuring the airflow direction towards chamber 4, not only is the powder effectively blocked, but the air curtain is also prevented from disturbing the material flow field and grinding effect within chamber 4.

[0025] Furthermore, the sealing structure near spindle 1 and the sealing structure near spindle 2 employ an asymmetrical, differentiated configuration. Specifically, the air curtain pressure of the second-stage sealing unit on the spindle 1 side, corresponding to high powder concentration and high pressure, is higher than that on the spindle 2 side, corresponding to low powder concentration and stable pressure. Because spindle 1 and spindle 2 face different powder concentrations and pressure intensities, a high-pressure air curtain is installed on the spindle 1 side for strong suppression, while an optimized moderate-pressure air curtain is arranged on the spindle 2 side, ensuring task completion while conserving resources. Through differentiated design for different operating conditions of the dual spindles, the sealing system achieves overall optimization, ensuring sealing reliability on the feed side under high load while achieving economy and stability on the non-feed side.

[0026] The skeleton oil seal 10 is made of high-temperature and high-pressure resistant material. Gas acts as the innermost line of defense, sealing the gas purified by the gas curtain formed by the second-stage sealing unit (such as inert gas or clean air), achieving zero leakage. Because no powder intrusion is observed, abrasive wear is avoided, and the oil seal life can reach ≥12 months. Preferably, the skeleton oil seal 10 is made of nitrile rubber, which possesses good wear resistance (coefficient of friction 0.05-0.08), oil resistance (suitable for small amounts of lubricating oil), and temperature resistance (-40℃-120℃). The principle of air curtain formation in the second-stage sealing unit is as follows: clean gas with a pressure higher than that in chamber 4 is introduced through high-pressure inlet ports III-1 and III-2, and the gas flows outward through the sealing gap (flow direction as follows). Figure 4 As indicated by the arrow, a continuous and uniform high-pressure positive pressure air curtain is formed; the air curtain pressure is higher than the pressure of chamber 4, preventing the ultrafine powder in chamber 4 from escaping to the first-stage sealing unit through the sealing gap, and controlling the powder concentration in the first-stage area at an extremely low level; at the same time, the air curtain flows out towards the lower side of the feed inlet 7 (material discharge direction), so as to avoid the air curtain disturbing the material flow field in the chamber.

[0027] The air curtain parameters for the third-stage sealing unit are: a clean gas with an inlet pressure higher than chamber 4 but lower than the second-stage air curtain pressure (same as the second stage), and the gas flow direction is as follows. Figure 4 As indicated by the arrow, the powder flows outward through the sealing gap; the third-stage sealing unit prevents powder backflow and intercepts trace amounts of powder escaping from the third-stage air curtain, further reducing the powder concentration in the second-stage area. This prevents powder from accumulating in the cavity between the grinding disc 3, the second rotating shaft support 6, and the wear-resistant inner ring 11, thus preventing increased running resistance or dynamic imbalance of the main shaft 1 due to powder accumulation. When the second-stage air curtain seal fails, the third-stage air curtain can temporarily act as an interception line, buying time for maintenance and preventing the first-stage main seal from being directly exposed to the powder environment.

[0028] The sealing structure on side 2 of the second main shaft is similar to the sealing structure described above. However, the powder concentration and pressure on this side are lower, resulting in higher cleanliness. The main structural differences in the sealing structure are as follows: The first-stage sealing unit is the same as the skeleton oil seal 10 on the main shaft-1 side. Since it is the non-feeding side, the pressure is relatively stable, and the fit tolerance of the skeleton oil seal can be appropriately relaxed to reduce the processing difficulty. The powder concentration of this first-stage sealing unit is lower than that of the first-stage sealing unit on the main shaft-1 side, and the cleanliness is higher. It can seal the gas and achieve zero leakage. Its service life is not less than 12 months.

[0029] The second-stage sealing unit has four high-pressure air inlets (I-1, I-2, I-3, I-4), circumferentially located on the annular end cap 14 and separated by an external spacer ring 12. This side has more high-pressure air inlets than the main shaft-1 side (inlets III-1, III-2), ensuring a more uniform air curtain. The upper side of the external spacer ring 12 connects to the end cap 14, which in turn connects to the side wall of the chamber 4; the lower side of the external spacer ring 12 connects to the grinding disc 3. This second-stage sealing unit forms a high-pressure air curtain, preventing powder from diffusing from the chamber into the first-stage main sealing unit, ensuring the cleanliness of the first-stage area.

[0030] The third sealing unit has two high-pressure air inlets (II-1, II-2), and a sealing gap of 0.2-0.25mm is reserved between the grinding disc 3 and the second rotating shaft support 6. The air curtain pressure formed by the third sealing unit is lower than that of the second-stage sealing unit. The third-stage sealing unit is used to prevent powder backflow and external impurities from entering, while reducing the powder concentration in the second-stage area, providing double protection for the first-stage main seal.

[0031] Furthermore, the high-pressure air inlet ports of both the second-stage and third-stage sealing units are chamfered to prevent eddies from forming during gas flow and to ensure the stability of the air curtain.

[0032] Before use, the inlet valve of the second-stage sealing unit is opened to introduce clean gas and maintain pressure; then the inlet valve of the third-stage sealing unit is opened and the pressure is adjusted to the preset value; the dual main shafts are started to rotate, and material is introduced into the chamber 4, with the air curtain running continuously to intercept the powder; the first-stage sealing unit seals the gas to ensure zero leakage; after shutdown, the material feeding is stopped first, and after the pressure in the chamber 4 drops to normal pressure, the inlet valves of the third-stage and second-stage sealing units are closed in sequence to prevent powder backflow when the machine is stopped.

[0033] The pressure monitoring system is as follows: This system includes multiple high-temperature resistant and contamination-resistant industrial-grade pressure sensors. Specifically, pressure sensor 17 is installed on the inner wall of chamber 5 to monitor chamber pressure P0; pressure sensor 18 is installed in channel I between the second and third stage sealing units on the spindle 1 side to monitor area pressure P1; pressure sensor 19 is installed in channel II between the second and third stage sealing units on the spindle 2 side to monitor area pressure P2; pressure sensors 20 and 21 are used to monitor leakage pressures P3 and P4, and to monitor whether the first-stage seal has failed; pressure sensor 20 is installed in channel VII outside the first-stage sealing unit on the spindle 1 side, and pressure sensor 21 is installed in channel V outside the first-stage sealing unit on the spindle 2 side. In addition, pressure sensors (not shown in the figure) are also installed at the air inlet of each sealing unit to collect the actual output pressure of the sealing unit in real time (for closed-loop control).

[0034] The pressure regulating assembly includes an air pump, a solenoid valve, and a pressure detector. These components are connected to the air inlets of each air curtain sealing unit (second stage and third stage) and are controlled by a central controller. The intake pressure is precisely controlled by adjusting the opening of the solenoid valve.

[0035] The adaptive pressure control method is as follows: (1) Pressure monitoring and signal processing: Each pressure sensor collects pressure data in real time and transmits it to the central controller via 485 communication or 4-20mA analog signal. The controller filters the data to eliminate interference caused by material impact and equipment vibration, and obtains stable real-time pressure values ​​P0, P1, P2, P3, and P4.

[0036] (2) Pressure difference calculation: The central controller calculates two key pressure differences: Main shaft 1 side: ΔP 10 = P1 - P0 Main shaft 2, side 2: ΔP 20 = P2 - P0 These two differences directly reflect the ability of the sealed air curtain to resist chamber pressure and prevent powder from escaping.

[0037] (3) Adaptive pressure regulation: The central controller will calculate ΔP 10 ΔP 20 It is compared with a preset threshold and a control signal is output to the pressure regulating component.

[0038] For the spindle 1 side: When ΔP 10 <ΔP 100 When the threshold (lower limit of the first difference threshold) is reached, it indicates insufficient sealing and a risk of leakage. The controller presses (ΔP)... 100 - ΔP 10 The positive correlation amplitude increases the intake pressure of the second and third stage sealing units.

[0039] When ΔP 10 >ΔP 101 When the first difference threshold is reached (upper limit), it indicates excessive sealing, leading to increased energy consumption and wear. The controller presses (ΔP)... 10 - ΔP 101 The positive correlation amplitude reduces the intake pressure of the second and third stage sealing units.

[0040] For the second side of the main shaft: When ΔP 20 <ΔP 200 When (the lower limit of the second difference threshold) is reached, it is calculated based on (ΔP). 200 - ΔP 20 The positive correlation with the upward pressure is expected.

[0041] When ΔP 20 >ΔP 201 When (the upper limit of the second difference threshold) is reached, it is calculated according to (ΔP). 20 - ΔP 201 The downward pressure is positively correlated with the magnitude of the adjustment.

[0042] This adjustment makes ΔP 10 and ΔP 20 It eventually stabilizes at [ΔP] 100 ΔP 101 ] and [ΔP 200 ΔP 201 Within the ideal range.

[0043] (4) Independent fine adjustment of the third-level sealing unit: For further optimization, the third-level sealing unit can also be adjusted independently.

[0044] When P1 <P 100 At that time, the pressure of the third-stage sealing unit on the main shaft side 1 is reduced, the magnitude of which is the same as (P). 100 - P1) positive correlation.

[0045] When P1>P 101At that time, the pressure of the third-stage sealing unit on the main shaft side 1 is increased, with the amplitude being the same as (P1-P). 101 (Positive correlation)

[0046] The adjustment logic for the second side of the main shaft is similar. Throughout this process, the pressure of the second-stage sealing unit on the same side must always be greater than the pressure of the third-stage sealing unit to maintain the correct airflow direction.

[0047] (5) Feedback and correction: After the adjustment in step (4), each pressure sensor continues to collect pressure data and feeds back the adjusted pressure signal to the central controller; the central controller recalculates ΔP. 10 ΔP 20 Given P1 and P2, determine whether the following conditions are met: ΔP 10 [ΔP 100 , ΔP 101 ]; ΔP 20 [ΔP 200 ,ΔP 201 ]; P1 [P 100 , P 101 ]; P2 [P 200 , P 201 ].

[0048] If the above conditions are not met, repeat step S4 for secondary adjustment until all parameters are within a reasonable range, thereby achieving dynamic adaptive balance of sealing pressure.

[0049] (6) Leakage monitoring and early warning: The controller monitors the leakage pressures P3 and P4 in real time.

[0050] If P3>P 30 If the preset leakage threshold is reached, the first-stage seal on the spindle-1 side is determined to be faulty, triggering an audible and visual alarm and prompting the replacement of the seal.

[0051] If P4>P 40 If the preset leakage threshold is reached, the first-stage seal on the second side of the main shaft is determined to be faulty, and an alarm is triggered.

[0052] Meanwhile, if the chamber pressure P0 exceeds the safety threshold, the system will trigger a "chamber pressure too high" warning and can automatically take measures such as speed reduction to protect the equipment.

[0053] In addition, the key strategies and parameter settings are as follows: Differentiated configuration: Given the more severe operating conditions of spindle 1 (feed side), its reference pressure value (P) is set accordingly.3-2基 ,P 3-3基 and the threshold values ​​for each pressure difference (ΔP) 100 ΔP 101 All of these values ​​are higher than the corresponding values ​​on the second side of the main spindle (P). 4-2基 , P 4-3基 ΔP 200 ΔP 201 The benchmark pressure value is set based on the following: On the same spindle side, ensuring the second-stage sealing reference pressure is greater than the third-stage sealing reference pressure is the physical basis for forming an "inward-oriented" airflow direction and ensuring the second-stage air curtain acts as the main interception layer and the third-stage air curtain as a safety redundancy layer. Violating this principle will lead to chaotic air curtain flow and seal failure. On different spindle sides, ensuring the reference pressure of spindle one (feed side) is greater than the corresponding reference pressure of spindle two (non-feed side) directly responds to the objective differences in operating conditions on both sides. The feed side experiences higher powder concentration and initial impact pressure, requiring a higher air curtain pressure to form an effective seal.

[0054] Multi-condition adaptation: The central controller pre-stores multiple sets of pressure reference values ​​and threshold parameters corresponding to different materials (such as high-hardness alumina and pharmaceutical powders) and processes (such as ultrafine grinding and surface modification). Operators can call these up with a single click through the human-machine interface to achieve quick switching.

[0055] Although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0056] Therefore, the above description is only a preferred embodiment of this application and is not intended to limit the scope of this application; that is, all equivalent modifications made in accordance with the scope of the claims of this application shall be within the protection scope of the claims of this application.

Claims

1. A method of adaptive pressure control for a twin-spindle pinner-disc mill sealing system, characterized by, The double-spindle disc mill comprises a feed-side spindle one (1) and a non-feed-side spindle two (2) rotating in opposite directions coaxially, a mill disc (3) arranged around the connection between the spindle one (1) and the spindle two (2), and a chamber (4) in communication with the mill disc (3), wherein a sealing structure is arranged at the connection between the mill disc (3) and the chamber (4), and along the center line direction of the mill disc (3), the sealing structure comprises, from the end far away from the chamber (4) to the end close to the chamber (4), a first-stage sealing unit, a second-stage sealing unit and a third-stage sealing unit in sequence, wherein the first-stage sealing unit is a contact-type mechanical seal, and the second-stage sealing unit and the third-stage sealing unit are non-contact-type air curtain seals. The control method comprises the following steps: S1, real-time monitoring of the internal pressure P0 of the chamber (4), the regional pressure P1 between the second-stage sealing unit and the third-stage sealing unit on the side of the spindle one (1), and the regional pressure P2 between the second-stage sealing unit and the third-stage sealing unit on the side of the spindle two (2); S2, calculate the pressure difference value ΔP of the main shaft one (1) side 10 = P1 - P0, and the pressure difference value ΔP of the main shaft two (2) side 20 = P2- P0; S3、the pressure difference value ΔP 10 is compared with a preset first difference threshold value, ΔP 20 is compared with a second difference threshold value, and according to the comparison result, the inlet pressure of the second and third sealing units is adaptively adjusted to make the pressure difference value ΔP 10 and ΔP 20 maintained within the respective preset threshold range.

2. The control method according to claim 1, characterized by, The adaptive adjustment specifically comprises: When △P 10 is lower than the first difference threshold lower limit △P 100 , the intake pressure of the second stage sealing unit and the third stage sealing unit on the main shaft one (1) side is adjusted upward, and the adjustment range is positively correlated with the value of (△P 100 - △P 10 ). When △P 10 is higher than the first difference threshold upper limit △P 101 , the intake pressure of the second stage sealing unit and the third stage sealing unit on the main shaft one (1) side is adjusted downward, and the adjustment range is positively correlated with the value of (△P 10 - △P 101 ); When △P 20 is lower than the second difference threshold lower limit △P 200 , the intake pressure of the second stage sealing unit and the third stage sealing unit on the main shaft two (2) side is adjusted upward, and the adjustment range is positively correlated with the value of (△P 200 - △P 20 ); When △P 20 is higher than the upper limit of the second difference threshold △P 201 , the intake pressure of the second stage sealing unit and the third stage sealing unit on the main shaft two (2) side is adjusted downward, and the adjustment range is positively correlated with the value of (△P 20 - △P 201 ).

3. The control method according to claim 2, characterized by, The control method further comprises an independent adjustment step for the third-stage sealing unit on the side of the spindle one (1): According to the comparison between P1 and the first difference value threshold, the pressure of the third-stage sealing unit is further optimized: When P1 100 , the intake pressure of the third stage sealing unit is down-regulated, and the amplitude is positively correlated with (P 100 -P1). When P1>P 101 , the intake pressure of the third stage sealing unit is up-regulated, and the up-regulation range is positively correlated with (P1-P 101 ); And the air inlet pressure of the second-stage sealing unit is always kept higher than that of the third-stage sealing unit on the same side.

4. The control method according to claim 2, characterized by, The control method further comprises an independent adjustment step for the third-stage sealing unit on the side of the spindle two (2): According to the comparison between P2 and the second difference value threshold, the pressure of the third-stage sealing unit is further optimized: When P2 200 , the intake pressure of the third stage sealing unit is down-regulated, and the amplitude is positively correlated with (P 20-0 -P2). When P2>P 201 , the intake pressure of the third stage sealing unit is up-regulated, and the up-regulation range is positively correlated with (P2-P 20-1 ).

5. The control method according to claim 1, characterized by, In step S1, the leakage pressures P3 of the first-stage sealing unit on the side of the spindle one (1) and the leakage pressure P4 of the first-stage sealing unit on the side of the spindle two are also monitored in real time. The control method further comprises a leakage warning step S4: When P3 exceeds a preset leakage threshold P 30 a pre-warning signal indicating that the first-stage sealing unit on the main shaft one (1) side is invalid is generated; When P4 exceeds a preset leakage threshold P 40 a pre-warning signal indicating that the first-stage sealing unit on the main shaft side 2 fails is generated.

6. The control method according to claim 1, characterized by The initial target pressure value, i.e. the reference pressure value, of each sealing unit is set, and the reference pressure value preset for the second-stage sealing unit and the third-stage sealing unit on the side of the spindle one (1) is higher than that preset for the corresponding sealing units on the side of the spindle two (2).

7. The control method according to claim 1, characterized by, The lower limit of the first pressure difference value threshold is higher than the upper limit of the first pressure difference value threshold.

8. An adaptive pressure control system for a multi-stage seal system of a double-spindle pug mill, the system comprising: The system for executing the control method as claimed in any one of claims 1-6 comprises: a central controller; a plurality of pressure sensors arranged inside the grinding chamber (4), between the second-stage sealing unit and the third-stage sealing unit on the side of the spindle one (1), and between the second-stage sealing unit and the third-stage sealing unit on the side of the spindle two (2), for collecting pressure data in real time and transmitting the data to the central controller; a pressure adjustment assembly connected with the air inlets of the second-stage sealing units and the third-stage sealing units and controlled by the central controller, for adjusting the air inlet pressure of each sealing unit.

Images