In cement production, the roller press is a key piece of equipment, and its operational stability directly affects production efficiency and product quality. Below are specific cases and experience sharing regarding fault handling from T Company, J Company, and S Company. If you encounter similar issues during equipment operation, feel free to contact us at Darko. As a professional manufacturer and supplier of cement equipment, we are dedicated to providing you with high-quality equipment and services.
Cement Plant A Abnormal Situation Description
Fault Phenomenon
Cement Plant A uses a vertical feeding pipe between the roller press and the weighing silo. However, this pipe is too short. As a result, the roller press experiences low working pressure and poor extrusion capability. Consequently, the feed material has high screening residue and low fine powder content. This situation leads to low system yield and high grinding energy consumption.
System Configuration
- Roller Press: 120-50 roller press (material throughput 165t/h, main motor power 250kW, current 21A×2)
- Dispersing and Classifying Machine: 550/120 (processing capacity 140—175t/h, motor power 45kW+30kW)
- Tube Mill: Φ3.2×13m three-chamber open circuit tube mill (main motor power 1600kW, grinding media loading 127t)
- Dust Collection Fan: Comprises an open circuit combined grinding system
Results
The system produces P.O42.5 grade cement with a finished specific surface area of at least 380±10m²/kg. It achieves a yield of 65t/h while consuming 35kWh/t of energy. However, the R80μm residue of the feed material reaches 78.7%, resulting in only 21.3% of the material being fine powder. This leads to a high content of coarse particles in the finished cement.
Technical Diagnosis Analysis
The vertical feeding pipe height between the roller press and the weighing silo is less than 1.2m, causing low material pressure in the pipe, requiring frequent adjustment of the rod valve. The weighing silo frequently experiences segregation or material collapse, and there is significant dust in the production area. The working pressure of the roller press is only 6.0—6.5MPa, which directly affects the extrusion effect of the material.
Technical Measures and Effects
During the annual overhaul, the height of the elevator and weighing silo was increased, raising the vertical feeding pipe height to 2.5m. The side plates of the roller press were repaired by overlay welding to reduce leakage. Maintaining the weighing silo's material level at 60%—70% eliminated segregation and material collapse. The working pressure of the roller press was adjusted to 7.2—7.5MPa, and the R80μm residue of the feed material was reduced to 49.8% (with the fine powder content reaching 50.2%). The system yield increased to 79t/h, and grinding energy consumption decreased to 26.4kWh/t. Annually, this modification can save 4.8 million kWh of electricity, resulting in an economic benefit of over 2.8 million RMB.
Cement Plant B Abnormal Situation Description
Fault Phenomenon
At Cement Plant B,operators face unstable feeding control to the roller press. This instability results in poor working capability. Consequently, the main motor produces insufficient output. As a result, the feed material contains low fine powder content. Ultimately, this situation leads to low yield and high grinding energy consumption.
Grinding System Configuration
- Roller Press: 170-100 roller press (material throughput 620t/h, main motor power 900kW)
- Classifier: Vx8820
- Tube Mill: φ4.2×13m double-chamber tube mill (main motor power 3550kW)
- Dust Collection Fan: Comprises a double closed-circuit combined grinding system
Results
The system produces P.O42.5 grade cement at a yield of 165t/h (finished fineness R45μm residue 9.0±1.0%), with grinding energy consumption reaching 44kWh/t.
Technical Diagnosis Analysis
The unstable feeding to the roller press results in poor extrusion capability and insufficient motor output, with the operating current only at 42%—45%. The specific surface area of the feed material is around 160m²/kg.
Technical Measures and Effects
A patent technology from a technology company, the "Lever-type Dual Feeding Device for Roller Press," was adopted to stabilize feeding control, increasing the main motor output to 72%—78%. Internal structural improvements ensured a higher content of finished material in the output. Ultimately, the system yield for P.O42.5 grade cement reached 210t/h, and grinding energy consumption decreased to 38.1kWh/t, achieving a 13.41% energy saving. After optimizing system power, production efficiency was significantly improved.
Cement Plant C Abnormal Situation Description
Fault Phenomenon
At Cement Plant C, both fly ash and desulfurized gypsum with small particle sizes enter the weighing silo together. The high moisture content of the desulfurized gypsum causes severe material adhesion on the silo walls, impacting the output of the roller press and the overall system yield.
Grinding System Configuration
- Roller Press: 120-50 roller press (material throughput 165t/h, main motor power 250kW)
- Dispersing and Classifying Machine: 550/120
- Tube Mill: Φ3.2×13m three-chamber tube mill (main motor power 1600kW)
- Dust Collection Fan: Comprises an open circuit combined grinding system
Results
The system produces P.O42.5 grade cement at a yield of 65t/h (finished specific surface area ≥ 360±10m²/kg), with grinding energy consumption of 33kWh/t. The R80μm residue of the feed material is more than 65% (with <80μm fine powder content around 35%).
Technical Diagnosis Analysis
The powdery materials affect the extrusion capability of the roller press, leading to low operating current. The weighing silo experiences severe material adhesion due to high moisture content, affecting the flow of material in the feeding pipe.
Technical Measures and Effects
Fly ash and desulfurized gypsum were switched to separate metering before direct feeding into the tube mill, and the adhesion on the walls of the weighing silo was cleaned to create stable material pressure. The roller press achieved over-saturated feeding, improving extrusion performance. The R80μm residue of the feed material was reduced to 55% (with <80μm fine powder content reaching 45%). The P.O42.5 cement yield increased to 75t/h, a rise of 15.38%; grinding energy consumption decreased to 30kWh/t, achieving a 9.1% energy saving.
Conclusion
The stable operation of the roller press is crucial for cement production. We can achieve this by monitoring equipment status and optimizing operational processes. Additionally, conducting regular maintenance helps us reduce faults effectively. This, in turn, improves production efficiency and enhances product quality. If you encounter any issues with cement equipment, please contact us. Darko, as a professional manufacturer and supplier of cement equipment, is committed to providing quality equipment and solutions. Together, we can drive progress in the industry.
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