Contents
Introduction
In cement manufacturing, the rotary kiln is the heart of the process. Maintaining its stability and efficiency hinges on monitoring a set of critical operating parameters. These parameters fall into five main categories: thermal, gas & air, feed & fuel, mechanical, and quality.
1. Thermal Parameters
- Burning Zone Temperature (BZT) – Target range 1400–1450 °C. Keeps the clinker formation zone at optimal heat.
- Kiln Inlet Temperature – Indicates heat‑transfer efficiency from the preheater.
- Preheater Outlet Temperature – Reflects cyclone efficiency and overall preheat performance.
- Clinker Temperature (Cooler Outlet) – Measures heat recovery and final product temperature.
2. Gas & Air Parameters
- Inlet O₂ % – Controls combustion quality.
- Outlet O₂ % – Ensures complete combustion.
- CO Level (ppm) – Detects incomplete combustion.
- Draft / Kiln Pressure (Pa) – Must remain negative to maintain proper airflow.
3. Feed & Fuel Parameters
- Feed Rate (TPH) – Governs production volume.
- Coal/Fuel Rate – Controls heat input.
- Filling Degree % – Represents material volume inside the kiln.
4. Mechanical Parameters
- Kiln RPM – Drives the rotation speed.
- Drive Load / Current – Indicates motor load.
- Tyre & Roller Temperature – Signals wear and heat buildup.
- Shell Temperature – Shows refractory condition.
5. Quality Parameters
- LSF, SM, AM (Raw Mix Chemistry) – Determines raw material balance.
- Free Lime (fCaO) – Major indicator of clinker quality.
- Clinker Liter Weight – Reflects product density.
Consequences of Parameter Disturbances
- Ring formation
- Coating problems
- High free lime content
- Kiln upset or trip
Conclusion
Consistent monitoring and control of these parameters ensure a stable, efficient kiln operation, preventing costly downtime and maintaining product quality.