Reliable continuous and point level measurement under actual process conditions
In aluminium foundries, casitng sand is a critical material used to form moulds for metal casting.
Maintaining a consistent supply is essential to ensure uninterrupted production. To achieve this, foundries must accurately monitor the quantity of sand stored in silos feeding the moulding process.
A UK aluminium casting facility faced challenges monitoring the level of casting sand in its main storage silo. While the silo was equipped with a point-level detection system to prevent overfilling, operators lacked visibility of the remaining sand volume during normal operation
To address this issue, the foundry tasked UWT UK Ltd to develop a solution capable of providing conitnuous, real-time level monitoring
The challenge
For many years, the facility relied on a Rotonivo rotary paddle switch to detect when the casting sand silo reached full capacity. Although effective as a high-level indicator, this device only provided a single switching point and did not measure the actual sand level within the silo.
Without continuous monitoring, operators were forced to estimate how much casting sand remained between refilling cycles. This created uncertainty around inventory levels and made it difficult to plan replenishment accurately.
In addition, the application environment presented several measurement challenges:
- Dust generation: Sand filling and discharge cycles produce airborne dust that can interfere with measurement signals.
- Small silo dimensions: Narrow silos increase the likelihood of measurement signals reflecting from silo walls.
- Potential signal interference: Internal reflections can create false readings if the sensor beam is too wide.
The foundry required a measurement technology that could overcome these challenges while providing reliable, continuous data.
The non-contact 80 GHz FMCW radar sensor NivoRadar® NR 4100 with a very narrow beam angle of 4° for continuous level measurement.
The solution
Following a site assessment, UWT recommended installing the Nivoradar 4100, an 80 GHz Frequency-Modulated Continuous-Wave (FMCW) radar level sensor designed for bulk-solid applications.
One of the key features influencing this selection was the radar sensor's 4° narrow beam angle, which allows the measurement signal to be precisely focused on the material's surface. By concentrating the radar energy within a small measurement area, reflections from silo walls and internal structures are minimised.
The radar's high operating frequency also improves measurement reolution and enhances its ability to distinguish the actual material surface from dust of other signal reflections.
To surther optimise performance, the radar sensor was installed using an aiming flange, allowing the beam to be directed towards the centre of the silo even though the sensor intself was not mounted centrally.
Installation & setup
Once the radar sensor was installed, UWT engineers returned to assist with commissioning the system.
The setup process was straightforward. After power was supplied to the sensor, configuration was completed via Bluetooth using the UWT LevelApp, enabling quick adjustment of measurement parameters.
The following measurement settings were configured:
- Full level (minimum measurement distance): 300 mm
- Empty level (maximum measurement distance): 6000 mm
These parameters defined the operating range for monitoring the casting sand level within the silo.
Signal verification & results
During commissioning, the radar signal quality was verified using the Echo Curve diagnostic feature available within the UWT LevelApp.
The Echo Curve provides a graphical representation of signal reflections detected at various distances from the sensor. A strong and clearly identifiable peak indicates a reliable reflection from the material surface.
In this case, a clear reflection was observed at approximately 5.5 metres, confirming that the silo was nearly empty at the time of testing. The signal sgtrength and clarity demonstrated that the radar sensor was correctly aligned and operqting without significant interference.
Rotonivo® RN 3002 with individually adjustable extension tube up to 4000 mm for precise switching point definition
Key benefits
Continuous level monitoring: Operators now have real-time visibility of casting sand levels instead of relying on a single high-level switch.
Improved process control: Better inventory tracking allows more accurate planning of refilling cycles.
Reliable operation in dusty environments: FMCW radar tachnology performs consistently despite airborne dust.
Simple commissioning and configuration: Bluetooth connectivity and mobile app configuration simplify installation and diagnostics.
"Thank you for your time yesterday. Your good humour and positive approach to the ever-changing circumstances were greatly appreciated." the plant operator confirmed.
Conclusion
The implementation of 80 GHz FMCW radar technology enabled the aluminium foundry to move from basic point-level detection to continuous level monitoring of its casting sand silo.
The Nivoradar 4100 sensor provedto be well-suited to the application, providing reliablemeasurements even in a dusty environment and within a narrow silo geometry.
Asa result,the foundry now benefits from improved visibility of itscasting sand inventory and greater confidence in managing its material supply.
UWT. LEVEL. UP TO THE MAX.
