Debunking the Myth: What Absorbed Power Really Means in Cement Grinding

In the cement industry, absorbed power is a crucial parameter that is closely monitored to ensure optimal grinding performance. However, many operators and engineers still believe that higher absorbed power always means better grinding. But is this really the case?

What Absorbed Power Really Reflects

Absorbed power is not just a measure of energy consumption; it is a direct indicator of mill load behavior and grinding conditions. In fact, high absorbed power can be a sign of overfilling, excessive material retention, increased internal circulation, and even coating, which can lead to reduced efficiency.

Key Factors Influencing Absorbed Power

• Mill Filling Degree: Optimal filling ensures effective impact and attrition.
• Grinding Media Condition: Worn-out or unbalanced media reduces energy transfer efficiency.
• Ventilation: Poor airflow can lead to material accumulation and increased power consumption without real grinding.
• Feed Characteristics: Hardness, moisture, and particle size directly affect power draw.
• Separator Efficiency: High reject can lead to increased circulating load and absorbed power.

Common Misconceptions

Many operators believe that increasing feed to raise power consumption will lead to better production. However, this is not always the case. In reality, you may increase power consumption without improving fineness or output.

Operational Insight

The goal of cement grinding is not to achieve maximum power consumption, but to optimize power at maximum efficiency. By understanding the factors that influence absorbed power, operators can make informed decisions to improve their mill’s performance and reduce energy consumption.

Practical Examples

Here are some practical examples of how to optimize absorbed power in cement grinding:

• Monitor mill motor current and compare it with the target operating range.
• Adjust feed rate automatically based on current levels.
• Optimize mill filling degree, grinding media condition, ventilation, feed characteristics, and separator efficiency.

FAQs

• Q: What is absorbed power in cement grinding? A: Absorbed power is a direct indicator of mill load behavior and grinding conditions.
• Q: Does higher absorbed power always mean better grinding? A: No, higher absorbed power can be a sign of overfilling, excessive material retention, increased internal circulation, and even coating.
• Q: What are the key factors influencing absorbed power? A: Mill filling degree, grinding media condition, ventilation, feed characteristics, and separator efficiency.
• Q: How can I optimize absorbed power in cement grinding? A: Monitor mill motor current, adjust feed rate automatically, optimize mill filling degree, grinding media condition, ventilation, feed characteristics, and separator efficiency.

Sources

• Emad Al-Naser, Operation Section Head, Manaseer Industrial Complex
• Oppatop Engineering Consultants Limited, Part 3: Using Ball Mill Current as an Effective Monitoring Parameter in Grinding Circuits
• Cement Grinding Handbook, Chapter 5: Monitoring and Control of Grinding Circuits

Original source: Cement Mill Power: Myth vs Reality | Emad ALNaser posted on the topic | LinkedIn