Definition of roller mill
مطحنة الأسطوانة is an ultra-fine grinding equipment with a fixed grinding ring (stator) and a rotating grinding roller (rotor) as core components. It mainly drives the grinding roller through centrifugal force to apply rolling, shearing and impact effects on the material to achieve efficient grinding of the material.
Precautions during grinding process of roller mill
1. Raw materials and feed control
· Material pretreatment
Control the moisture content of feed to ≤1% (lower for materials prone to blockage), to avoid agglomeration in the grinding chamber due to excessive humidity.
Remove metal impurities from the material to prevent damage to the grinding roller/grinding ring. It is recommended to install an iron remover at the feed inlet.
· Feed control
The particle size of feed must be ≤ the maximum allowable particle size designed (usually 20-30mm), and coarse materials must be crushed in advance.
· Feed hardness
Roller mill is mainly suitable for materials with hardness ≤6.
2. parameter optimization
· Pressure and speed regulation
Dynamically adjust the roller pressure according to the hardness of the material (usually 0.5-2.0MPa). For hard materials, the pressure needs to be increased but not exceed the rated value of the equipment.
The main engine speed is controlled at 70%-80% of the critical speed (calculation formula: n=42.3/√D, D is the diameter of grinding ring ).
· Air volume and classification efficiency
Adjust the air volume of the fan so that the velocity reaches 15-25m/s to ensure that fine powder is discharged in time and avoid over-grinding.
The classifier speed is adjusted by the frequency converter, and the deviation of the target particle size D97 is controlled within ±5%.
3. Operational process specifications
· Start-up and shutdown sequence
Auxiliary equipment (fan, dust collector) → main machine → feeder; shutdown sequence is the opposite to avoid material retention.
After stopping feeding, there is still material in the chamber, and all the stored materials must be ground and discharged before stopping the machine. Generally, after stopping feeding, the machine should be kept running for about 5 minutes.
· Feed stability
Use a quantitative feeder (such as a belt weigher + inverter combination) to ensure uniform feeding, with a fluctuation range of ≤5%. In the event of a sudden material shortage, reduce the host power immediately to prevent idling and damage to the equipment.
4. Operation monitoring and maintenance
· Real-time parameter monitoring
Focus on monitoring the main engine current (not exceeding 90% of the rated current), bearing temperature (≤70℃), and vibration value (≤3.5mm/s).
Configure an online particle size analyzer to record D50/D97 data every hour and promptly investigate any abnormal fluctuations.
· Maintenance of wearing parts
Check the wear of the grinding roller/grinding ring regularly (it is recommended to check every 200 hours). If the wear on one side is greater than 3mm, turn it over for use.
When replacing the grinding roller, check chamber lining simultaneously. If the wear depth is greater than 5mm, the wear-resistant lining needs to be replaced.
5. Response to special working conditions
· High humidity material
Add a hot air system (inlet temperature 100-150℃) and adjust the air volume to prevent condensation.
Use pulse dust collector and shorten the cleaning cycle to avoid filter bag clogging.
· Inflammable and explosive materials
Configure an inert gas protection system (such as a nitrogen filling device) to control the oxygen content to less than 8%.
Use anti-static filter bags and grounding devices to eliminate hidden dangers of static electricity.
خاتمة
If we follow the above precautions during the grinding process of roller mill, the operating stability of the roller mill can be significantly improved and the equipment life can be extended.
شركة تشينغداو إبيك لآلات المساحيق المحدودة is a powder processing equipment الشركة المصنعة with rich experience and technical accumulation.
Our products include:
— المطاحن: مطحنة الكرات, مطحنة الأسطوانة, air classifier mill, jet mill, impact mill, etc.
— Air classifiers: هيئة تحرير الشام, مركز التجارة الدولية, CTC, MBS and TDC.
— Surface coating and modification: معدل مطحنة الدبوس, معدل طاحونة ثلاثية الدوارات و معدل طاحونة التوربو.
— Related auxiliary equipment:خزانة التحكم، مرشح كيس, belt weigher, etc.
Among them, roller mill is one of our grinding products. It has low energy consumption, high efficiency and high classification accuracy, and is widely praised by consumers.
If you need roller mill or other powder processing equipment, please اتصل بموظفينا directly. We will provide you with a one-stop solution from equipment selection, solution design to installation and commissioning, and after-sales service.
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