A method for improving the reliability of lignite dryer transmission and load bearing

Abstract

This application discloses a method for improving the transmission and load-bearing reliability of a lignite dryer, applied to a drum-type lignite dryer, including the following steps: S1, calibrating the coaxiality and levelness of the support roller load-bearing components at both ends of the drying drum. This allows for dynamic adjustment of the gear meshing clearance based on the moisture content and feed rate fluctuations of the lignite feed, compensating for transmission deformation deviations caused by high-moisture heavy-load impacts. By precisely calibrating the coaxiality, levelness, and contact angle of the support rollers, uniform force is ensured on each support roller. Simultaneously, the load-bearing contact surface is subjected to high-frequency induction hardening treatment to form a high-hardness, wear-resistant hardened layer, significantly improving the wear resistance and impact resistance of the contact surface. This effectively avoids problems such as scratches, peeling, and excessive wear on the contact surface that occur during long-term operation. By collecting real-time data on drum movement, load, and vibration, a linkage model between operating conditions and equipment parameters is established to ensure long-term continuous and reliable operation of the equipment.

Description

Technical Field

[0001] This application relates to the technical field of dryers, and more particularly to a method for improving the transmission and load-bearing reliability of lignite dryers. Background Technology

[0002] Lignite has a high moisture content, a large amount of dust, and fluctuates significantly in its incoming material conditions, requiring dehydration and upgrading via a rotary drum dryer before use. The transmission and load-bearing systems of the rotary drum lignite dryer are crucial for stable operation, directly impacting overall efficiency, service life, and production safety. In actual production, existing lignite dryers exhibit poor adaptability in their transmission and load-bearing structures, revealing numerous shortcomings.

[0003] First, most existing dryers adopt a passive operation mode with fixed meshing clearance and fixed tension. The moisture content and feed rate of lignite fluctuate greatly. The impact of high-moisture, heavy-load materials can easily cause elastic and plastic deformation of gears and transmission shafts. The fixed transmission clearance cannot compensate for the deformation error under working conditions in time, which can easily lead to problems such as poor gear meshing and transmission jamming. This not only reduces transmission efficiency and increases operating energy consumption, but also accelerates the fatigue wear of transmission components.

[0004] Secondly, the contact surfaces between the load-bearing rollers and the support rollers are often not specially reinforced, resulting in poor surface wear resistance. Under long-term heavy-load rotation and material impact and friction, they are prone to scratches, wear, peeling and other defects, which further cause imbalance of the cylinder, running vibration and axial displacement. In severe cases, it can lead to cylinder deformation and cracking, overheating and burning of the support rollers, and other failures, which greatly shorten the service life of the load-bearing components.

[0005] In addition, the equipment often adopts a manual inspection method with periodic shutdowns. Under continuous variable load, the roller is prone to problems such as excessive axial movement and excessive unilateral bearing deviation. The deviation cannot be corrected in real time and continues to accumulate, causing the equipment to vibrate more and the transmission to deviate, forming a vicious cycle of wear and vibration, which seriously reduces the operating accuracy and structural stability of the equipment.

[0006] Application content

[0007] This application aims to address, at least to some extent, the technical problems in the related art.

[0008] To achieve the above objectives, this application proposes a method for improving the transmission and load-bearing reliability of a lignite dryer, applicable to a drum-type lignite dryer, comprising the following steps:

[0009] S1. The coaxiality and levelness of the support rollers at both ends of the drying drum are calibrated to match the variable load characteristics of lignite drying conditions. The contact angle between the support rollers and the drum belt is adjusted to 25°-35°. The uniformity error of the support roller force is controlled to ≤3%. At the same time, the load-bearing contact surface is quenched and wear-resistant to form a wear-resistant hardened layer with a thickness of 0.8-1.2mm.

[0010] S2. Real-time acquisition of data on gear meshing clearance, chain tension, and radial runout of the transmission drive assembly of the dryer. Based on the fluctuations in the moisture content and feed rate of the lignite feed, dynamically adjust the transmission fit clearance to stably control the gear meshing clearance at 0.15-0.3mm and the radial runout of the transmission shaft at ≤0.02mm.

[0011] S3. For the high temperature and high dust conditions of the dryer, an oil-gas separation precision lubrication method is adopted. The transmission bearing and load bearing are replenished with lubricating oil in a timely and quantitative manner. The lubricating oil replenishment cycle is matched with the drum speed and set to 1-4 hours / time. At the same time, the bearing operating temperature is monitored in real time. When the temperature exceeds 75℃, the air cooling heat dissipation is automatically started to keep the bearing operating temperature constant at 40-70℃.

[0012] S4. Real-time acquisition of vibration data, axial movement and load data of the drying drum, and establishment of a linkage model between lignite drying conditions and equipment operating parameters. When the axial movement of the drum is detected to be ≥0.5mm or the load deviation of the single-sided support roller is ≥5%, the roller tilt angle and transmission tension are automatically adjusted to achieve dynamic correction of the operating status.

[0013] S5. A multi-level dustproof sealing structure is set for the transmission meshing parts, bearing fit clearance, and load-bearing contact surfaces. A labyrinth seal combined with a flexible dustproof felt provides double protection, preventing lignite dust from entering the transmission and load-bearing fit clearance during the drying process. At the same time, the dust accumulated in the sealing cavity is blown away regularly.

[0014] In addition, the application may also include the following additional technical features:

[0015] Specifically, in step S1, the coaxiality of the support rollers is calibrated using a laser alignment instrument, and the levelness is calibrated using an electronic level. After calibration, the coaxiality error of the support rollers at both ends of the drying drum is ≤0.03mm / m, and the levelness error is ≤0.02mm / m.

[0016] Specifically, in step S1, the wear-resistant hardened layer is prepared by high-frequency induction hardening process, the hardness of the hardening is controlled at HRC55-HRC62, and the surface roughness of the hardened layer Ra≤1.6μm.

[0017] Specifically, in the dynamic adjustment of the transmission clearance in step S2, for the feeding condition of high-moisture lignite with a moisture content >35%, the transmission clearance is increased by 0.05-0.1mm to compensate for the transmission deformation caused by the heavy impact of high-moisture material; for the conventional condition with a moisture content ≤35%, the standard transmission clearance is maintained.

[0018] Specifically, in step S3, the lubricating oil used is a high-temperature resistant and anti-wear synthetic lubricating oil with a flash point ≥220℃ and a viscosity grade of VG68, which is suitable for the working environment of the lignite dryer chamber at 80-120℃. The amount of lubrication replenishment each time is precisely controlled according to the bearing specifications.

[0019] Specifically, in step S4, the lignite drying condition-equipment operation parameter linkage model has built-in load threshold, vibration threshold, and axial movement threshold. It collects equipment operation data in real time and compares it with the threshold. The single correction adjustment amount is ≤0.2° of the roller tilt angle and ≤0.1mm of the transmission tension.

[0020] Specifically, in step S5, the labyrinth sealing gap of the multi-level dustproof sealing structure is controlled at 0.08-0.12mm, and the flexible dustproof felt is made of high-temperature resistant flame-retardant needle-punched felt with a thickness of 3-5mm.

[0021] Specifically, it also includes regular non-destructive testing and predictive maintenance steps: weekly ultrasonic non-destructive testing of rollers, drive shafts, and gear meshing surfaces; monthly testing of bearing wear and hardened layer wear thickness; and proactive repair and maintenance when wear exceeds a preset threshold.

[0022] Specifically, in step S6, the preset thresholds are set as follows: bearing radial wear ≥ 0.1 mm, load-bearing hardened layer wear thickness ≥ 0.3 mm, gear tooth surface wear ≥ 0.2 mm. Once the thresholds are reached, grinding repair, welding hardening, or component replacement is performed immediately.

[0023] Specifically, during the operation of the lignite dryer, the drum speed is adjusted in conjunction with the fluctuation of the feed rate. When the instantaneous fluctuation of the feed rate is ≥10%, the drying drum speed and transmission output torque are adjusted simultaneously. The speed adjustment range is controlled within 5%-10% of the rated speed, and the torque adjustment response time is ≤2s.

[0024] In summary, the beneficial effects of the method for improving the transmission and load-bearing reliability of lignite dryers proposed in this application are as follows:

[0025] 1. The gear meshing clearance can be dynamically adjusted according to the moisture content and feed rate fluctuation of lignite feed to compensate for the transmission deformation deviation caused by high moisture and heavy load impact. By precisely controlling the gear meshing clearance and the radial runout of the transmission shaft, problems such as poor transmission meshing, jamming, and loosening can be effectively avoided, thereby improving transmission efficiency, reducing operating energy consumption, significantly alleviating fatigue wear of transmission components, and extending the service life of transmission components.

[0026] 2. By precisely calibrating the coaxiality, levelness, and contact angle of the support rollers, uniform force is ensured on each support roller. At the same time, the load-bearing contact surface is subjected to high-frequency induction hardening treatment to form a high-hardness, wear-resistant hardened layer, which significantly improves the wear resistance and impact resistance of the contact surface. This can effectively avoid problems such as scratches, peeling, and excessive wear on the contact surface that occur during long-term operation, and eliminate faults such as unbalanced force on the cylinder, vibration deviation, overheating and bearing failure of the support rollers, and deformation and cracking of the drum, thus greatly improving the stability and service life of the load-bearing system.

[0027] 3. By collecting real-time data on roller movement, load, and vibration, a linkage model between working conditions and equipment parameters is established. The roller tilt angle and transmission tension are automatically and finely adjusted for deviations exceeding the standard, achieving real-time dynamic correction. This effectively suppresses the accumulation of operating deviations, solves problems such as increased equipment vibration and transmission misalignment, breaks the vicious cycle of wear and vibration, significantly improves the operating accuracy and overall structural stability of the equipment, and ensures long-term continuous and reliable operation of the equipment. Attached Figure Description

[0028] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0029] Figure 1 This is a schematic diagram of a method for improving the transmission and load-bearing reliability of a lignite dryer according to this application. Detailed Implementation

[0030] To make the technical means, inventive features, objectives, and effects of this application easier to understand, the application is further described below with reference to specific illustrations. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0031] The present application will now be described in further detail with reference to the accompanying drawings.

[0032] like Figure 1 As shown, an embodiment of this application discloses a method for improving the transmission and load-bearing reliability of a lignite dryer, applied to a drum-type lignite dryer, comprising the following steps:

[0033] S1. The coaxiality and levelness of the support rollers at both ends of the drying drum are calibrated to match the variable load characteristics of lignite drying conditions. The contact angle between the support rollers and the drum belt is adjusted to 25°-35°. The uniformity error of the support roller force is controlled to ≤3%. At the same time, the load-bearing contact surface is quenched and wear-resistant to form a wear-resistant hardened layer with a thickness of 0.8-1.2mm.

[0034] It should be noted that, using the theoretical rotation center of the drying drum as a reference, the coaxiality and levelness of the load-bearing components of the two end support rollers are calibrated to eliminate dimensional and positional deviations caused by installation and long-term operation, providing a basic accuracy guarantee for uniform load transfer. Considering the variable load characteristics caused by fluctuations in feed rate and material moisture content during lignite drying, the contact angle between the support rollers and the drum belt is adjusted to the range of 25°-35°. By optimizing the contact angle to distribute radial load and axial limiting load, the stress state of the support rollers is adapted to the fluctuations in operating conditions.

[0035] During calibration, the uniformity of force distribution on each support roller is controlled to be ≤3% to avoid early fatigue failure caused by overload of a single set of support rollers. At the same time, the load-bearing contact surfaces of the support rollers and rollers are subjected to quenching and wear-resistant treatment to form a wear-resistant hardened layer with a thickness of 0.8-1.2mm, which improves the wear resistance of the contact surface, reduces the wear rate during long-term operation, and extends the maintenance cycle of load-bearing components.

[0036] S2. Real-time acquisition of data on gear meshing clearance, chain tension, and radial runout of the transmission drive assembly of the dryer. Based on the fluctuations in the moisture content and feed rate of the lignite feed, dynamically adjust the transmission fit clearance to stably control the gear meshing clearance at 0.15-0.3mm and the radial runout of the transmission shaft at ≤0.02mm.

[0037] It should be noted that during the operation of the lignite dryer, fluctuations in the feed moisture content and feed rate directly lead to changes in the drum load, which in turn causes misalignment of the transmission clearance and a decrease in operational stability. This step involves real-time acquisition of data on gear meshing clearance, chain tension, and radial runout of the drive shaft in the transmission drive components. The transmission operating parameters are correlated with the feed condition parameters, and the transmission clearance is dynamically adjusted according to load fluctuations. By dynamically compensating for the fit deviation caused by load changes, the gear meshing clearance is stably controlled within 0.15-0.3 mm, balancing lubrication film formation and transmission accuracy requirements. Simultaneously, the radial runout of the drive shaft is controlled to ≤0.02 mm, reducing the additional dynamic load caused by eccentric operation and ensuring long-term reliable operation of the transmission system under fluctuating operating conditions.

[0038] S3. For the high temperature and high dust conditions of the dryer, an oil-gas separation precision lubrication method is adopted. The transmission bearing and load bearing are replenished with lubricating oil in a timely and quantitative manner. The lubricating oil replenishment cycle is matched with the drum speed and set to 1-4 hours / time. At the same time, the bearing operating temperature is monitored in real time. When the temperature exceeds 75℃, the air cooling heat dissipation is automatically started to keep the bearing operating temperature constant at 40-70℃.

[0039] It should be noted that this step is suitable for the high-temperature and high-dust operating environment of lignite dryers. By combining precise lubrication with active temperature control, the stable operation of transmission and load-bearing bearings is ensured. The high-temperature environment of lignite drying will accelerate the deterioration of lubricating oil, and the high-dust environment will easily cause contamination of the lubricating medium. Conventional lubrication methods are difficult to maintain the long-term stable operation of bearings.

[0040] This step employs a precise oil-gas separation lubrication method, providing timed and quantitative lubricant replenishment to the transmission and load-bearing bearings. The lubrication replenishment cycle is set to match the drum speed, with a frequency of 1-4 hours per replenishment. The lubrication frequency is adjusted according to the operating speed to ensure effective lubrication while avoiding dust adhesion caused by excessive lubricant. Simultaneously, the bearing operating temperature is monitored in real time. When the detected temperature exceeds 75℃, air cooling is automatically activated to maintain the bearing operating temperature within the 40-70℃ range, preserving the lubricant's performance stability, suppressing abnormal bearing thermal expansion, and reducing the risk of bearing failure due to high temperatures.

[0041] S4. Real-time acquisition of vibration data, axial movement and load data of the drying drum, and establishment of a linkage model between lignite drying conditions and equipment operating parameters. When the axial movement of the drum is detected to be ≥0.5mm or the load deviation of the single-sided support roller is ≥5%, the roller tilt angle and transmission tension are automatically adjusted to achieve dynamic correction of the operating status.

[0042] It should be noted that this step achieves online dynamic correction of the drying drum's operating status through multi-parameter monitoring and operational condition linkage analysis, thus preventing the cumulative expansion of operating deviations into equipment failure.

[0043] During long-term operation, the drying drum is prone to problems such as excessive axial movement and uneven load distribution on the support rollers due to factors such as contact surface wear, material uneven loading, and thermal deformation. Continuous deterioration will exacerbate damage to load-bearing and transmission components. This step involves real-time acquisition of vibration data, axial movement data, and load data of the drying drum. A linkage model between operating conditions and equipment parameters is established based on the characteristics of lignite drying, enabling real-time analysis and prediction of the operating status. When the axial movement of the drum is detected to be ≥0.5mm, or the load deviation of a single support roller is ≥5%, the system automatically fine-tunes the support roller tilt angle and transmission tension, correcting the drum's operating posture online. This dynamic correction of the operating status can be achieved without stopping the machine, continuously maintaining the equipment in optimal operating condition.

[0044] S5. A multi-level dustproof sealing structure is set for the transmission meshing parts, bearing fit clearance, and load-bearing contact surfaces. A labyrinth seal combined with a flexible dustproof felt provides double protection, preventing lignite dust from entering the transmission and load-bearing fit clearance during the drying process. At the same time, the dust accumulated in the sealing cavity is blown away regularly.

[0045] It should be noted that this step, through a combination of multiple sealing structures and a periodic dust removal mechanism, prevents lignite dust from intruding into the transmission and load-bearing parts, thereby reducing the impact of abrasive wear on system reliability.

[0046] The large amount of fine dust generated during lignite drying can exacerbate abrasive wear on components if it penetrates the meshing surfaces of transmissions, bearing clearances, and load-bearing contact surfaces, significantly contributing to decreased reliability of transmission and load-bearing systems. This step addresses this by implementing a multi-level dustproof sealing structure for transmission meshing areas, bearing clearances, and load-bearing contact surfaces. It employs a labyrinth seal combined with flexible dustproof felt for dual protection, using a stepped blocking mechanism to prevent lignite dust from entering various clearances. Simultaneously, a periodic purging mechanism is implemented to clean dust accumulated in the sealed cavities, maintaining the protective performance of the sealing structure and extending the service life of transmission and load-bearing components under high-dust conditions.

[0047] In one embodiment of this application, the coaxiality calibration of the support rollers in step S1 is detected by a laser alignment instrument, and the levelness calibration is detected by an electronic level. After calibration, the coaxiality error of the support rollers at both ends of the drying drum is ≤0.03mm / m, and the levelness error is ≤0.02mm / m.

[0048] It should be noted that the coaxiality calibration of the rollers is performed using a high-precision laser alignment instrument. Relying on the high-precision, non-contact, and real-time numerical visualization advantages of the laser alignment instrument, it can accurately capture the radial and angular positional deviations of the drying drum roller assembly. It is suitable for the overall alignment calibration of long-span rollers and effectively avoids problems such as human reading errors, blind spots, and cumulative assembly errors that exist in traditional detection methods.

[0049] The high-precision electronic level used for leveling calibration completes full-area testing, covering points such as the roller support base, shaft mounting surface, and drum support contact surface. This comprehensive control ensures the accuracy of the equipment installation benchmark. After meticulous calibration and debugging, the coaxiality error of the rollers at both ends of the drying drum is ≤0.03mm / m, and the levelness error is ≤0.02mm / m. This high-precision calibration standard can prevent problems such as drum sway, uneven local stress, unilateral overload wear of the rollers, and transmission jamming from the source. It significantly improves the stability of the lignite dryer during long-term continuous operation, reduces the probability of equipment vibration, abnormal noise, and fatigue wear of parts, and lays a precise equipment installation foundation for subsequent processes such as wear-resistant layer application, transmission operation, and sealing protection.

[0050] In one embodiment of this application, the wear-resistant hardened layer in step S1 is prepared by high-frequency induction hardening process, the hardness of the hardening is controlled at HRC55-HRC62, and the surface roughness of the hardened layer Ra≤1.6μm.

[0051] It should be noted that the wear-resistant hardened layer is prepared using a high-frequency induction hardening process. This process utilizes the principle of high-frequency electromagnetic induction to rapidly and locally heat components such as the bearing contact surfaces of rollers and drums. Combined with an integrated processing method of precise temperature control and rapid quenching and cooling, it has the advantages of uniform heating, small thermal deformation, strong bonding of the hardened layer, and no damage to the matrix properties. It can form a dense and uniform wear-resistant hardened structure on the key bearing friction surfaces of the equipment.

[0052] During the processing, parameters such as quenching temperature, heating time, and cooling rate are precisely controlled to stably maintain the hardness of the hardened layer within the HRC55-HRC62 range. This hardness range is suitable for the complex working conditions of material scouring, continuous load-bearing, and reciprocating friction during lignite drying, combining high strength, wear resistance, and impact resistance, thus avoiding the problems of excessive hardness leading to brittle cracking or excessive softness causing rapid wear. Controlling the surface precision ensures that the surface roughness Ra of the hardened layer is ≤1.6μm. The smooth and dense surface structure effectively reduces lignite material adhesion and dust accumulation, lowers frictional resistance and abrasive wear during equipment operation, significantly extends the service life of core wear-resistant components, and reduces the frequency of equipment maintenance.

[0053] In one embodiment of this application, during the dynamic adjustment of the transmission clearance in step S2, for the feeding condition of high-moisture lignite with a moisture content >35%, the transmission clearance is increased by 0.05-0.1mm to compensate for the transmission deformation caused by the heavy impact of the high-moisture material; for the conventional condition with a moisture content ≤35%, the standard transmission clearance is maintained.

[0054] It should be noted that the transmission clearance adopts a dynamic adaptive adjustment mode, which can accurately match the clearance parameters according to the differences in lignite feeding conditions. The moisture content of lignite directly determines the material's specific gravity, bulk density, and impact load, and is a core factor affecting the stability of the equipment's transmission. A 35% moisture content is used as the working condition boundary threshold to achieve refined and differentiated control. For high-moisture lignite feeding conditions with a moisture content >35%, high-moisture lignite is characterized by high viscosity, thick bulk, and strong feeding impact load. The equipment's transmission system is prone to elastic deformation and compressive stress under heavy load impact. In this case, actively increasing the transmission clearance by 0.05-0.1mm can accurately compensate for the slight deformation of components such as transmission gears, couplings, and drive shafts under heavy load conditions, effectively avoiding problems such as transmission component seizure, tooth surface extrusion wear, abnormal operating noise, and torque transmission jamming, ensuring smooth and stable power transmission.

[0055] For conventional drying feed conditions with a moisture content of ≤35%, the material is loose, the impact load is small, and the transmission operation load is stable. No additional adjustment is required. Maintaining the standard transmission clearance of the equipment can ensure transmission accuracy and power transmission efficiency, avoiding defects such as transmission looseness, speed deviation, and running vibration caused by excessive clearance, and achieving the optimal operating state of the transmission system under different feeding conditions.

[0056] In one embodiment of this application, the lubricating oil used in step S3 is a high-temperature resistant and anti-wear synthetic lubricating oil with a flash point ≥220℃ and a viscosity grade of VG68, which is suitable for the working environment of the lignite dryer chamber at 80-120℃, and the amount of lubrication replenishment each time is precisely controlled according to the bearing specifications.

[0057] It should be noted that, considering the harsh operating conditions of lignite dryers—long-term operation under high temperatures, high dust levels, and continuous heavy loads—a high-temperature resistant and wear-resistant synthetic lubricating oil is selected. This lubricating oil has a flash point ≥220℃, effectively resisting the continuous high-temperature environment of 80-120℃ within the dryer chamber. This prevents problems such as lubricating oil evaporation, carbonization, failure, and carbon buildup under high-temperature conditions, eliminating lubrication failure, high-temperature wear of components, and jamming caused by oil deterioration. The oil viscosity grade adopts the VG68 standard. This viscosity parameter maintains a stable oil film thickness and fluidity within the normal operating temperature range of the equipment. It can form a high-strength, pressure-resistant lubricating oil film to resist the heavy friction pressure of bearings, while avoiding problems such as increased transmission resistance and energy consumption due to excessive viscosity, or oil film rupture and insufficient lubrication due to excessive viscosity.

[0058] At the same time, a precise lubrication replenishment mechanism is established. Based on parameters such as the inner diameter, load coefficient, operating speed, and friction working surface volume of different specifications of bearings in the dryer, the amount of lubricating oil replenished at one time is accurately calculated to achieve quantitative and precise replenishment. This not only prevents problems such as dust accumulation, oil buildup, and increased transmission resistance caused by excessive replenishment, but also avoids dry friction and rapid wear of components caused by insufficient replenishment, thus continuously ensuring the lubrication stability and long-term effectiveness of bearings and transmission rotating components.

[0059] In one embodiment of this application, the lignite drying condition-equipment operation parameter linkage model in step S4 has built-in load threshold, vibration threshold, and axial movement threshold. The equipment operation data is collected in real time and compared with the threshold. The single correction adjustment amount is ≤0.2° roller tilt angle and ≤0.1mm transmission tension.

[0060] It should be noted that during equipment operation, the model uses high-precision sensors to collect core operational data in real time, such as the roller load, the vibration frequency and amplitude of the entire machine, and the axial displacement of the roller. The real-time data is dynamically compared with built-in preset thresholds at the millisecond level to accurately identify minute operational deviations and abnormal operating conditions. To ensure equipment operational stability and avoid secondary impact damage caused by large adjustments, the model limits the precision of single-step correction adjustments. Specifically, the single-step correction adjustment of the support roller tilt angle is ≤0.2°, and the single-step tension adjustment of the transmission tensioning structure is ≤0.1mm. This micro-precision correction mode enables refined and gradual correction of equipment deviations, continuously stabilizing the equipment operating parameters within the optimal range and ensuring long-term, high-precision, and low-loss continuous operation of the lignite dryer.

[0061] In one embodiment of the present application, the labyrinth seal gap of the multi-stage dust-proof seal structure in step S5 is controlled at 0.08-0.12mm, and the flexible dust-proof felt adopts high-temperature resistant and flame-retardant needled felt with a thickness of 3-5mm.

[0062] It should be noted that, in view of the working condition characteristics of lignite drying process, such as large amount of dust, strong permeability of fine dust, high cavity temperature and frequent air flow disturbance, the sealing structure parameters and sealing materials are optimized to improve the dust-proof sealing performance of the equipment. The gap of the labyrinth seal structure is precisely controlled at 0.08-0.12mm. The gap size is optimized and designed through working condition simulation, which can form air flow damping by using the labyrinth zigzag air flow channel, effectively block the fine lignite dust inside the drying cavity from penetrating and overflowing outward, and at the same time avoid the problems of component friction and jamming caused by too small gap and seal failure caused by too large gap, taking into account both sealing performance and equipment operation flexibility. The flexible dust-proof felt matched with the multi-stage dust-proof structure is made of high-temperature resistant and flame-retardant needled felt, which has the characteristics of high temperature resistance, flame retardancy, aging resistance, moderate air permeability and high dust interception rate, is suitable for the high-temperature operation environment of the dryer, and is not prone to problems such as high-temperature deformation, hardening, damage and failure.

[0063] At the same time, the thickness of the dust-proof felt is controlled at 3-5mm. This thickness range can balance the dust interception effect and the ventilation and pressure relief demand, which can not only efficiently intercept fine dust, prevent the problems of external dust accumulation of equipment, environmental pollution and dust jamming and wear of transmission components caused by dust leakage, but also ensure the normal circulation of a small amount of air flow in the cavity, and avoid the accumulation of cavity pressure affecting the stability of drying working conditions.

[0064] In one embodiment of the present application, the method further includes regular non-destructive testing and predictive maintenance steps: ultrasonic non-destructive testing is performed on the supporting rollers, transmission shafts and gear meshing surfaces every week, the bearing wear amount and the wear thickness of the hardened layer are tested every month, and repair and maintenance are carried out in advance when the wear amount exceeds a preset threshold.

[0065] It should be noted that a hierarchical and graded periodic testing mechanism is formulated, and the testing covers the key components of the equipment for core load-bearing, transmission and wear resistance. Among them, the transmission and load-bearing components are tested once a week, and the ultrasonic non-destructive testing technology is adopted to carry out non-destructive flaw detection on the main structure of the supporting roller, the body of the transmission shaft and the meshing working surface of the gear, so as to accurately investigate potential faults that cannot be identified by the naked eye, such as internal microcracks, recessive damage and meshing defects of the components, and avoid sudden equipment failures caused by continuous expansion of recessive damage.

[0066] Monthly quantitative wear testing of components is conducted to accurately measure key wear parameters such as the actual wear of bearings and the residual wear thickness of the load-bearing hardened layer, enabling quantitative control of wear status. The system records data from each test in real time, establishing a wear trend ledger. When the wear or damage of a component reaches a preset threshold, a predictive maintenance process is immediately initiated to carry out targeted repairs and maintenance in advance, preventing minor wear and defects from escalating into major equipment failures.

[0067] In one embodiment of this application, the preset thresholds in step S6 are set as follows: bearing radial wear ≥ 0.1 mm, load-bearing hardened layer wear thickness ≥ 0.3 mm, gear tooth surface wear ≥ 0.2 mm. Once the thresholds are reached, grinding repair, welding hardening, or component replacement is performed immediately.

[0068] It should be noted that the bearing radial wear ≥ 0.1mm, the wear thickness of the load-bearing hardened layer ≥ 0.3mm, and the gear tooth surface wear ≥ 0.2mm are threshold values ​​that are precisely set based on the equipment wear patterns and component design life of the lignite dryer under heavy load, continuous, and dusty conditions. These are critical indicators to ensure the equipment's operational accuracy and safety performance. When the wear parameters of any core component reach the above-mentioned preset thresholds, the component is deemed to have exceeded the wear limit and its operational accuracy has failed. The machine must be immediately stopped for specialized repair work. A corresponding repair plan will be matched according to the degree of component wear. For slightly worn areas, fine grinding repair will be carried out to eliminate wear burrs and working surface deformation defects.

[0069] For components with worn hardened layers but intact substrates, a repair welding and hardening process is used to re-prepare the wear-resistant layer, restoring the component's wear resistance and structural precision. For severely worn, structurally fatigued, and irreparable core components, complete replacement is performed. Through precise threshold determination and a tiered processing mechanism, the system effectively ensures that all core components of the equipment are always in a qualified operating condition, maintaining the equipment's transmission precision, load-bearing stability, and sealing reliability, significantly reducing equipment downtime and maintenance costs.

[0070] In one embodiment of this application, the rotational speed of the drying drum is adjusted in conjunction with the fluctuation of the feed rate during the operation of the lignite dryer. When the instantaneous fluctuation of the feed rate is ≥10%, the rotational speed of the drying drum and the transmission output torque are adjusted simultaneously. The speed adjustment range is controlled within 5%-10% of the rated speed, and the torque adjustment response time is ≤2s.

[0071] It should be noted that during actual operation, the instantaneous feed flow rate of the equipment is monitored in real time to accurately determine the fluctuation range of the feed rate. When the instantaneous fluctuation range of the feed rate is ≥10%, the equipment is determined to have entered a variable load impact condition. The system immediately links and adjusts the operating speed of the drying drum and the transmission output torque to offset the sudden load shock caused by the sudden increase or decrease in the feed rate. To ensure the stability of the drying condition and the safety of equipment operation, the adjustment range and response speed are limited. The adjustment range of the drum speed is controlled within 5%-10% of the rated speed of the equipment to achieve smooth fine-tuning and avoid large fluctuations in speed affecting the uniformity of lignite drying; the transmission torque adjustment response time is ≤2s to promptly match the real-time feed load.

[0072] This linkage control method can effectively reduce the instantaneous pressure and fatigue wear of core components such as the roller bearing structure, transmission gears, and bearings caused by variable load impacts, significantly slow down the fatigue aging rate of equipment components, and at the same time ensure the stability of lignite drying quality under different feed fluctuation conditions, taking into account both equipment service life and product production quality.

[0073] The present application and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present application. The actual structure is not limited to this. In conclusion, if a person skilled in the art is inspired by this description and designs a similar structure and embodiment without departing from the spirit of the present application, such design should fall within the protection scope of the present application.

Claims

1. A method for improving the reliability of transmission and load-bearing capacity in a lignite dryer, characterized in that, Applied to drum-type lignite dryers, the process includes the following steps: S1. The coaxiality and levelness of the support rollers at both ends of the drying drum are calibrated to match the variable load characteristics of lignite drying conditions. The contact angle between the support rollers and the drum belt is adjusted to 25°-35°. The uniformity error of the support roller force is controlled to ≤3%. At the same time, the load-bearing contact surface is quenched and wear-resistant to form a wear-resistant hardened layer with a thickness of 0.8-1.2mm. S2. Real-time acquisition of data on gear meshing clearance, chain tension, and radial runout of the transmission drive assembly of the dryer. Based on the fluctuations in the moisture content and feed rate of the lignite feed, dynamically adjust the transmission fit clearance to stably control the gear meshing clearance at 0.15-0.3mm and the radial runout of the transmission shaft at ≤0.02mm. S3. For the high temperature and high dust conditions of the dryer, an oil-gas separation precision lubrication method is adopted. The transmission bearing and load bearing are replenished with lubricating oil in a timely and quantitative manner. The lubricating oil replenishment cycle is matched with the drum speed and set to 1-4 hours / time. At the same time, the bearing operating temperature is monitored in real time. When the temperature exceeds 75℃, the air cooling heat dissipation is automatically started to keep the bearing operating temperature constant at 40-70℃. S4. Real-time acquisition of vibration data, axial movement and load data of the drying drum, and establishment of a linkage model between lignite drying conditions and equipment operating parameters. When the axial movement of the drum is detected to be ≥0.5mm or the load deviation of the single-sided support roller is ≥5%, the roller tilt angle and transmission tension are automatically adjusted to achieve dynamic correction of the operating status. S5. A multi-level dustproof sealing structure is set for the transmission meshing parts, bearing fit clearance, and load-bearing contact surfaces. A labyrinth seal combined with a flexible dustproof felt provides double protection, preventing lignite dust from entering the transmission and load-bearing fit clearance during the drying process. At the same time, the dust accumulated in the sealing cavity is blown away regularly.

2. The method for improving the transmission and load-bearing reliability of a lignite dryer according to claim 1, characterized in that, In step S1, the coaxiality of the support rollers is calibrated using a laser alignment instrument, and the levelness is calibrated using an electronic level. After calibration, the coaxiality error of the support rollers at both ends of the drying drum is ≤0.03mm / m, and the levelness error is ≤0.02mm / m.

3. The method for improving the transmission and load-bearing reliability of a lignite dryer according to claim 1, characterized in that, In step S1, the wear-resistant hardened layer is prepared by high-frequency induction hardening process, the hardness of which is controlled at HRC55-HRC62, and the surface roughness of the hardened layer Ra≤1.6μm.

4. The method for improving the transmission and load-bearing reliability of a lignite dryer according to claim 1, characterized in that, In step S2, during the dynamic adjustment of the transmission clearance, for high-moisture lignite feeding conditions with a moisture content >35%, the transmission clearance is increased by 0.05-0.1mm to compensate for the transmission deformation caused by the heavy impact of high-moisture materials; for conventional conditions with a moisture content ≤35%, the standard transmission clearance is maintained.

5. The method for improving the transmission and load-bearing reliability of a lignite dryer according to claim 1, characterized in that, In step S3, the lubricating oil used is a high-temperature resistant and wear-resistant synthetic lubricating oil with a flash point ≥220℃ and a viscosity grade of VG68, which is suitable for the working environment of the lignite dryer chamber at 80-120℃. The amount of lubrication replenishment each time is precisely controlled according to the bearing specifications.

6. The method for improving the transmission and load-bearing reliability of a lignite dryer according to claim 1, characterized in that, In step S4, the lignite drying condition-equipment operation parameter linkage model has built-in load threshold, vibration threshold, and axial movement threshold. It collects equipment operation data in real time and compares it with the threshold. The single correction adjustment amount is ≤0.2° roller tilt angle and ≤0.1mm transmission tension.

7. The method for improving the transmission and load-bearing reliability of a lignite dryer according to claim 1, characterized in that, In step S5, the labyrinth seal gap of the multi-level dustproof sealing structure is controlled at 0.08-0.12mm, and the flexible dustproof felt is made of high-temperature resistant flame-retardant needle-punched felt with a thickness of 3-5mm.

8. The method for improving the transmission and load-bearing reliability of a lignite dryer according to claim 1, characterized in that, It also includes regular non-destructive testing and predictive maintenance steps: weekly ultrasonic non-destructive testing of rollers, drive shafts, and gear meshing surfaces; monthly testing of bearing wear and hardened layer wear thickness; and proactive repair and maintenance when wear exceeds a preset threshold.

9. A method for improving the transmission and load-bearing reliability of a lignite dryer according to claim 8, characterized in that, In step S6, the preset thresholds are set as follows: bearing radial wear ≥ 0.1 mm, load-bearing hardened layer wear thickness ≥ 0.3 mm, gear tooth surface wear ≥ 0.2 mm. Once the thresholds are reached, grinding repair, welding hardening, or component replacement is performed immediately.

10. A method for improving the transmission and load-bearing reliability of a lignite dryer according to claim 1, characterized in that, During the operation of the lignite dryer, the drum speed is adjusted in conjunction with the feed rate fluctuation. When the instantaneous fluctuation of the feed rate is ≥10%, the drying drum speed and transmission output torque are adjusted simultaneously. The speed adjustment range is controlled within 5%-10% of the rated speed, and the torque adjustment response time is ≤2s.

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