Smart Char Bed Measurement creates a 3D model of the recovery boiler char bed and its location using video feeds from multiple furnace cameras positioned on different walls. Char bed geometry and position data are delivered to the DCS via OPC UA for improved combustion management.
The Challenge
The char bed — the pile of burning smelt solids at the base of the recovery boiler furnace — directly influences combustion air distribution, chemical reduction efficiency, and smelt flow characteristics. Char bed height and position must be actively managed to maintain stable combustion and safe boiler operation. Traditional assessment relies on operator observation through sight glasses, which is subjective, infrequent, and limited to a two-dimensional perspective. Without objective 3D data on char bed geometry, operators cannot optimize air management or detect abnormal conditions early.
The ANDRITZ Solution
Smart Char Bed Measurement is a video-based system that constructs a three-dimensional model of the recovery boiler char bed from multiple furnace camera feeds. By combining images from cameras positioned on different walls, the system triangulates char bed position and geometry, delivering objective and continuous 3D data for combustion management.
How It Works
At least two furnace cameras positioned on different walls provide simultaneous video feeds of the char bed. The system processes these feeds to reconstruct a 3D model of the char bed — including its height, shape, and lateral position within the furnace. Measurement values are transmitted to the plant DCS via OPC UA, where they can be displayed for operator use or integrated into combustion control logic for air distribution optimization.
Key Benefits
- Objective, continuous 3D characterization of char bed position and geometry
- Supports optimized air distribution for stable char bed height and combustion performance
- Early detection of char bed asymmetry or abnormal growth before operational upsets occur
- OPC UA integration enables direct display on DCS and use in control applications
- Replaces subjective manual observation with repeatable, quantitative measurement
Integration & Compatibility
The system requires at least two furnace cameras on different walls and transmits data via OPC UA to the plant DCS. It is designed for kraft pulp mill recovery boilers. Confirm camera specifications, placement requirements, and DCS integration details with ANDRITZ for a specific installation.
Smart Smelt Flow Measurement uses video analysis of smelt spout CCTV cameras to measure smelt flow velocity, volumetric flow rate, and spout fouling index in recovery boilers. Measurement values are shared via OPC UA and the fouling index can be used to trigger or control smelt spout cleaning robots.
