Chinese
Spanish
Russian
Portuguese
French
German
Indonesian
Thai
Vietnamese
Arabic
Italian
Turkish
Polish
Japanese
Coal bunker level measurement can show a high pile while the feeder below it is starved. A bridge, an inactive outlet or an asymmetric valley can separate the observed surface from the material available to the process. Define whether the instrument is intended to manage free space, follow extraction or estimate stock before choosing its position.
Follow the tripper and outlet geometry
A travelling tripper can move the filling peak across the bunker. Multiple feeders can create different discharge profiles even when the total stored quantity changes slowly. Map the possible inlet positions and active outlet combinations; assess whether one beam can answer the operating question throughout those combinations.
The METRAVON MV-RD21 provides a bulk-solids radar option with a 76 mm PTFE lens and nominal 3-degree beam. The narrow path can help locate a measurement between obstructions, but it samples a surface region rather than the whole bunker. If the operation needs several independent zones, determine their coverage instead of treating a longer range as a substitute.
Interpret coal bunker level measurement alongside feeder records
| Trend | Possible explanation | Next check |
|---|---|---|
| High and steady | The beam sees stored coal, not necessarily moving coal. | Compare feeder status and downstream delivery before declaring fuel available. |
| Sudden fall | A local collapse or a change of dominant echo may have occurred. | Review the process event and echo together before adjusting calibration. |
| Jump on filling | The tripper stream or new peak may enter the beam. | Compare the tripper position with the installation drawing. |
| Unchanged value | The surface may be stable, or the system may be holding stale data. | Check measurement validity and timestamp at the receiving controller. |
Specify electrical and area requirements explicitly
Order the output needed by the existing PLC: 4-20 mA/HART and an RS485/Modbus RTU arrangement are not interchangeable wiring descriptions. For a retrofit, verify the supply, cable route, isolation and diagnostic handling before reusing the old circuit. Keep raw level and any calculated stock value distinguishable on the operator display.
Dust-hazard requirements must be matched to documentation for the exact assembly. An IP enclosure rating, a temperature rating or a generic product-family approval does not establish suitability for the classified location. This radar is also not a coal-temperature, gas or fire detector.
Commission against operating combinations
Use a planned sequence that includes the relevant tripper positions and feeder combinations at accessible levels. Record distance, echo quality, indicated level and controller status. The reference measurement must describe the same part of the pile; a wall-side observation cannot automatically validate a central peak reading.
For inventory estimates, retain the pile and bulk-density assumptions with the conversion. Recheck them when coal grade or handling changes. A good local distance measurement can coexist with a poor whole-bunker tonnage estimate.
Operator questions
Q1. Should an empty feeder automatically mean a radar fault?
No. Investigate the material path and feeder operation as well as the sensor. A correct high-level reading may be reporting coal that is not reaching that outlet. Use the plant's approved procedure for inspecting suspected blockages.
Q2. Can one radar provide the sole overfill protection?
That requires a separate protective-system assessment. Do not infer independence, diagnostic coverage or a safety rating from the availability of a continuous level output.
Summary
Send the tripper travel, outlet arrangement and intended control task with your coal-bunker instrument enquiry. The quotation should explain which surface is measured and how an unavailable reading is handled, not just list a maximum distance.
