This article presents a detailed case study of a pulverized coal positive pressure pneumatic conveying project implemented for a coal chemical enterprise in Yulin, Shaanxi Province. The project was successfully delivered by Shandong Headpowder Engineering Co., Ltd., a leading provider of powder handling solutions. The following content elaborates on the project background, technical challenges, system design, equipment selection, and operational outcomes. It is intended to serve as a reference for professionals in the coal chemical industry seeking reliable material conveying systems.
The Yulin region in Shaanxi Province is one of China's major coal chemical industrial bases. The client, a large-scale coal chemical enterprise, required a highly efficient and safe system for conveying pulverized coal from storage facilities to downstream reactors. The existing mechanical conveying methods suffered from dust leakage, high maintenance costs, and limited conveying distance. To address these issues, the client sought a coal powder positive pressure pneumatic conveying solution that could handle fine, abrasive, and potentially explosive materials. Shandong Headpowder Engineering Co., Ltd. was selected based on its proven track record in coal chemical material conveying and powder conveying system engineering.
Pulverized coal has a particle size typically below 200 mesh, making it prone to agglomeration, segregation, and static electricity buildup. The conveying system had to operate under positive pressure to prevent air ingress and maintain stable flow. Additionally, the coal dust is classified as combustible, requiring strict adherence to explosion-proof standards. The client specified a conveying capacity of 15 tons per hour over a distance of 350 meters with multiple bends. The system also needed to integrate with existing coal mill outlets and storage silos. Headpowder's engineering team conducted a thorough site survey and material analysis to design a customized solution.
The core of the solution was a positive pressure dense phase pneumatic conveying system. Unlike dilute phase conveying, dense phase technology uses lower air velocities and higher material-to-air ratios, reducing wear and energy consumption while maintaining stable flow. The system included a rotary airlock feeder, a pressure vessel, a conveying pipeline with wear-resistant bends, and a bag filter receiver. The pressure vessel was designed with a cone bottom and fluidizing nozzles to ensure complete discharge. The pipeline layout minimized sharp turns and used long-radius bends lined with ceramic tiles to extend service life. All components were selected to meet ATEX or equivalent explosion-proof standards.
During the commissioning phase, the system demonstrated excellent performance. The coal powder positive pressure conveying achieved a consistent throughput of 15.2 tons per hour with a conveying pressure of 0.25 MPa. The air-to-material ratio was optimized to 1.5:1, significantly lower than conventional dilute phase systems. This resulted in a 30% reduction in compressed air consumption compared to the client's previous system. The conveying velocity was maintained between 6 and 8 meters per second, effectively preventing pipe blockages and minimizing dust generation. The system operated with a noise level below 85 dB at the silo top, meeting workplace safety regulations.
The coal chemical material conveying system was seamlessly integrated into the existing production line. The pulverized coal was fed from the mill to the pressure vessel via a rotary valve, then conveyed to a 1000 m³ storage silo. From the silo, the coal was further distributed to gasifiers through a separate conveying branch. The control system used a PLC with remote monitoring capability, allowing operators to adjust feed rates and monitor pressure, temperature, and flow in real time. The system also included a nitrogen purge function for emergency shutdown, ensuring safety during maintenance. The overall powder conveying system engineering covered design, fabrication, installation, and commissioning within a 6-month schedule.
Given the combustible nature of pulverized coal, the conveying system incorporated multiple safety features. The pressure vessel and pipeline were equipped with rupture discs and pressure relief valves. The bag filter used antistatic filter media and a grounding system to dissipate static charges. An oxygen analyzer continuously monitored the internal atmosphere, and inert gas injection was automatically triggered if oxygen levels exceeded 8%. The system also included a suppression system using water mist at critical points. These measures ensured compliance with GB 50016 and similar international standards for combustible dust handling. The client's safety team conducted a HAZOP study and confirmed that the risk level was reduced to an acceptable range.
One of the key advantages of the dense phase conveying design is its low maintenance requirement. The ceramic-lined bends have a projected lifespan of over 5 years under normal operating conditions. The rotary airlock feeder uses a replaceable wear sleeve, and the pressure vessel's fluidizing nozzles are made of stainless steel to resist corrosion. The control system provides predictive maintenance alerts based on pressure drop variations and motor current trends. During the first year of operation, the system achieved an availability of 98.5%, with only scheduled shutdowns for filter bag replacement. The client reported a 40% reduction in overall maintenance costs compared to their previous mechanical conveyors.
Upon completion, the project was recognized as a successful example of coal powder positive pressure pneumatic conveying in the coal chemical industry. The client's production manager noted that the system eliminated dust leakage, improved workplace cleanliness, and reduced energy consumption by 25%. The coal chemical material conveying efficiency was enhanced, allowing the plant to increase throughput without expanding physical footprint. The powder conveying system engineering provided by Shandong Headpowder Engineering Co., Ltd. was praised for its technical rigor and responsive after-sales support. The client has since ordered a second system for a new production line.
Shandong Headpowder Engineering Co., Ltd. is headquartered in Shandong Province, China. The company specializes in the design, manufacture, and installation of pneumatic conveying systems for a wide range of powders, including pulverized coal, fly ash, cement, petrochemical powders, and food ingredients. With over 15 years of experience, Headpowder has completed more than 200 projects globally. The company's engineering team provides customized solutions for demanding applications, including high-temperature, high-pressure, and explosive environments. For inquiries regarding similar projects, please contact the project manager: Mr. Zhang. WeChat: 15662777102. The team is available to discuss technical requirements and provide preliminary system designs.
This case study demonstrates that positive pressure dense phase pneumatic conveying is a reliable and efficient solution for coal chemical material handling. The Yulin project highlights the importance of proper system design, material characterization, and safety integration. Shandong Headpowder Engineering Co., Ltd. continues to innovate in powder conveying system engineering, developing new wear-resistant materials and intelligent control algorithms. The company is committed to helping clients achieve sustainable and safe production. For further information, reach out to Mr. Zhang via WeChat: 15662777102. Headpowder looks forward to partnering with enterprises that require advanced pneumatic conveying technology.
Shandong Headpowder Engineering Co., Ltd.
156-6277-7102（Zhang manager） 
0531-83386006 
Jinan City, Shandong, China Province 
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