In the explosive hazardous environment of underground coal mines where the methane concentration reaches 5% to 15%, the third-generation explosion-proof roller pulley developed by Xin Aneng has reduced the safety accident rate caused by electric sparks in the conveying system by 87%, and the continuous trouble-free operation time of the equipment has exceeded 12,000 hours. This product, through triple protection of material explosion-proof, structure anti-static and intelligent monitoring, has been applied in 17 mines with an annual output of over 10 million tons, including the National Energy Group, and has cumulatively reduced economic losses by more than 320 million yuan.
Intrinsically safe materials block the combustion chain
The drum body is made of a composite structure of Q345B low alloy steel and flame-retardant reinforced nylon, with a 0.8mm thick nano-scale aluminum-magnesium alloy coating sprayed on the surface. In the actual measurement of a coal mine in Shanxi Province, this coating can increase the minimum ignition energy of the methane-air mixture from 0.28mJ to 1.2mJ, which is more than four times the requirement of the MT/T 818.1-2009 standard. The seams of the cylinder body are welded by laser cladding process, with the weld strength reaching 92% of the base material, eliminating the spark risk points generated by traditional riveted structures.
The electrostatic dissipation system controls the accumulation of charges
The bearing housing integrates carbon fiber conductive brushes and grounding devices to form a static conduction path with a resistance value of less than 1×10⁶Ω. In the continuous monitoring of a certain mine in Inner Mongolia, this design reduced the surface potential of the drum from 15kV to below 0.8kV, which is much lower than the critical electric field intensity of coal dust explosion (3×10⁶V/m). The conductive brush is made of copper-plated carbon fiber composite material, which has a wear resistance 300% higher than that of pure copper brushes and a maintenance cycle extended to 18 months.
The double-sealed structure isolates flammable media
The bearing cavity adopts dual protection of labyrinth seal and air seal, and is equipped with an end cover design of IP69K protection grade. In the water spray test of a high-gas mine in Guizhou, this structure controlled the leakage of lubricating oil within 0.5ml/h and prevented the invasion of external coal dust by 99.6% at the same time. The air seal system forms a positive pressure barrier through 0.2MPa compressed air, which is particularly suitable for negative pressure environments such as gas drainage tunnels.
The temperature monitoring module enables early warning
It is equipped with a built-in PT1000 platinum resistance temperature sensor and a wireless transmission module, which can monitor the working temperature of the bearing in real time. When the temperature exceeds 85℃, the system automatically triggers the deceleration protection. Cut off the power supply when the temperature reaches 105℃. In the application of an intelligent mine in Shaanxi Province, this function issued a 12-minute early warning of bearing lubrication failure, thus preventing a major equipment fire accident. The temperature monitoring accuracy reaches ±0.5℃, which complies with the intrinsically safe circuit design requirements of GB/T 3836.4-2021.
The explosion-proof certification system ensures compliance
The product has passed the MA coal safety certification, Ex dIMb explosion-proof grade certification and IECEx international certification. The explosion-proof mark is completely marked on the drum nameplate. In the random inspection conducted by the National Mine Safety and Supervision Bureau in 2024, the spark test, overload test and other 12 indicators of the XinAneng explosion-proof drum all exceeded the requirements of the MT 818.7-2009 standard. Each device is equipped with a unique explosion-proof qualification certificate number, enabling full-process traceability from production to use.
Modular design simplifies underground maintenance
The hub and the cylinder adopt a quick-release connection structure and are equipped with explosion-proof hydraulic wrenches, allowing for overall replacement within 30 minutes. In an emergency drill at a certain mine in Anhui Province, this design reduced the time for fault repair by 65% compared with the traditional structure, effectively controlling the risk of gas accumulation. A dual mechanical interlock device is set at the module interface to prevent the failure of explosion-proof performance caused by misoperation.
The impact-resistant structure is suitable for harsh working conditions
The reinforcing ribs of the cylinder body adopt a variable cross-section trapezoidal design, with an impact resistance energy of up to 5000J (equivalent to a 10kg drop hammer freely falling from a height of 5m). In the actual measurement of a certain rock burst mine in Henan Province, this structure kept the deformation of the drum within 2mm under frequent impacts, ensuring the smooth operation of the conveyor belt. The reinforcing ribs are connected to the cylinder body through friction welding technology, and the fatigue life of the weld seam exceeds 2 million cycles.
Industry application cases establish the authority of the technology
The products have been successfully applied to key projects such as the 10m/s ultra-high-speed conveying system of Zhangji Coal Mine of China Coal Group and the 3000m long-distance conveying project of Jinchitan Coal Mine of Shandong Energy. At the 2024 China International Mining Equipment Exhibition, XinAneng explosion-proof drum won the "Gold Award for Innovative Products in Intelligent Coal Mine Construction", and its technical solution was included in the "Coal Industry Safety Production Standardization Manual" under the section on conveying equipment.
