In modern cement pyroprocessing, the control of tertiary air plays a decisive role in kiln stability, calciner performance, and alternative fuel utilization. As plants increasingly operate with multi‑fuel strategies and higher thermal substitution rates, the need for accurate and reliable tertiary air flow measurement becomes critical.
The application environment presents some of the harshest conditions within the cement plant. High dust loads with elevated clinker concentrations, process gas temperatures reaching up to 1200 °C (≈ 2200 °F), and continuous 24/7 operation place extreme demands on any measurement technology. At the same time, operators require clear insight into how combustion air is distributed between the alternative fuel reactor and the kiln inlet.
Without accurate measurement, tertiary air control is often based on assumptions rather than actual flow data. This can lead to unstable combustion conditions, gas overfeeding, process imbalances, increased risk of incomplete combustion, and unplanned calciner or kiln disturbances. Precise and reliable tertiary air measurement is therefore essential to maintain balanced combustion, ensure energy efficiency, and support long‑term process optimization.
An effective tertiary air measurement solution must meet several key requirements:
Meeting these requirements reliably over long production campaigns is not achievable with conventional point measurement or mechanical flow solutions.
To address these challenges, a digital tertiary air flow measurement system based on Promecon’s McON® IR infrared technology was implemented.
The system was installed in a rising section of the tertiary air duct (TAD), carefully selected to ensure representative and stable flow conditions. This installation strategy is critical for achieving accurate and repeatable measurements in high‑dust, high‑temperature environments.
The Promecon McON® IR system uses a non‑intrusive infrared measurement principle that determines gas velocity by detecting temperature fluctuations carried by the gas stream. Because no mechanical components extend into the process, the system is inherently resistant to abrasion, fouling, and drift.
The solution provides continuous real‑time measurement of:
This data gives operators direct visibility into actual tertiary air behavior, rather than inferred or calculated values.
With real‑time tertiary air flow data available, operators can actively manage air distribution between the kiln inlet and the alternative fuel combustion reactor. Precise damper adjustments become possible based on actual process conditions, enabling:
The availability of continuous data also improves process evaluation during load changes, fuel mix transitions, and startup or shutdown sequences.
The McON® IR sensor design is engineered specifically for extreme cement plant environments. Its key features include:
These characteristics allow uninterrupted long‑term operation without mechanical intervention, making the solution well suited for continuous production environments.
With reliable tertiary air measurement and control in place, plants implementing the Promecon McON® IR solution have achieved significant performance improvements, including:
These results demonstrate how accurate measurement forms the foundation for improved control, higher efficiency, and long‑term process stability.
In cement pyroprocessing, control challenges cannot be solved without accurate data. Reliable tertiary air flow measurement enables operators to move from estimation to precise control, supporting stable combustion, higher alternative fuel usage, and improved energy performance.
By leveraging the non‑intrusive, maintenance‑free capabilities of Promecon McON® IR, producers gain the confidence and insight needed to optimize one of the most critical airflow paths in the kiln system.
Better data leads to better decisions, and better performance.