Large quantities of wood shavings and wood chips are generated during wood processing operations. In many facilities, these residual materials are utilised for energy generation and are combusted to produce heat and electricity.
Reliable Monitoring of Wood Shavings
At a major European manufacturer of wood-based materials, the resulting wood residues are utilised in an on-site biomass power plant. Before being used for energy generation, the materials are temporarily stored in several silos.
Level monitoring of the facility is managed centrally via a control system. Around 300 measurement points are integrated into the central plant visualisation system. For point level detection within the silos, UWT Rotonivo® RN 6003 and RN 6004 rotary paddle level switches had already been installed.
Challenge: Elevated Temperatures and Fast Status Recognition
Due to the close proximity of the biomass power plant and the resulting radiant heat, elevated process temperatures are also present within the silo installations. At the same time, operating conditions must be recognised quickly in order to carry out service activities efficiently and avoid plant downtime.
Although a central process visualisation system was already in place, there was a need for an additional local status indication directly at each silo. The objective was to identify switching states immediately on site without having to access the central control system first.
Robust Rotary Paddle Switches for Demanding Applications
Rotonivo® rotary paddle switches have been used for point level monitoring in the installation for many years. The sensors were specifically developed for demanding bulk solids applications and are suitable for full, demand and empty level detection in storage and process vessels.
The Rotonivo® RN 6003 is designed for process temperatures up to +250 °C and process pressures up to 10 bar. The RN 6004 is suitable for even more demanding applications with process temperatures of up to +600 °C.
Both devices feature robust housings for use in hazardous areas and are SIL2 certified. Large terminal compartments simplify wiring and facilitate the retrofit of additional components such as the NivoLED® signal light. In addition, the rotary paddle switches are highly resistant to mechanical loads.
Solution: Retrofitting NivoLED® Signal Lights
To improve visibility directly at the silos, a pilot installation was carried out on one silo equipped with existing Rotonivo® point level switches by adding the NivoLED® NL 9000 signal light.
The LED device visualises the current switching status directly at the measuring point, providing immediate visual feedback for operating personnel. Its 360° visibility and high-intensity dual-colour LED indication in red and green ensure that switching states can be reliably recognised even from greater distances or under poor visibility conditions.
The benefits of the local status indication became apparent during the test phase. Defined limit levels could be identified more quickly, while maintenance and service activities were carried out more efficiently. This helped shorten response times and reduce potential downtime during operation.
Following the successful trial, the solution was expanded to additional measuring points. In total, 18 additional NivoLED® signal lights were installed throughout the facility.
Customer Benefits: Improved Visibility and Faster Response Times
The local status visualisation provides several advantages, particularly in large industrial facilities:
- Improved visibility directly at the silos
- Faster recognition of switching states
- Simplified maintenance and service activities
- Reduced response times in the event of process deviations
- Enhanced process safety during operation
The local status indication helps optimise workflows while reducing unnecessary travel distances and delays.
Designed for Hazardous Areas in the Wood Industry
The NivoLED® was specifically developed for industrial applications in demanding environments. The signal light features a highly visible 360° LED display for visualising sensor and equipment status.
Thanks to its robust design and ATEX and IECEx approvals, the solution is particularly suitable for hazardous and dust-intensive environments commonly found in wood processing facilities.
The signal light can be integrated directly on sensors, control cabinets or process equipment and is ideally suited for the retrofit of existing installations.
Small Upgrade – Significant Impact
This application demonstrates how relatively small modifications to existing measuring points can deliver measurable benefits in daily plant operation. Especially in complex industrial facilities with a large number of measurement points, local status visualisation contributes to greater transparency, improved safety and faster response times.
