A 1,200°C flare is worth specifying only when emission performance is a hard requirement and cost is not the constraint. Otherwise a 1,000°C enclosed flare normally meets the standard. That was the supplier’s own advice when a European equipment maker asked for a closed flare range quote: a 1,200°C design adds cost for minimal additional advantage, unless quality is the first requirement.
The challenge: choosing the temperature class
Two enquiries from northern Europe show the choice. One asked for a closed flare package across a range of sizes from 100 to 10,000 m³/h. Another asked for a 1,700 m³/h unit for a landfill site. In both, the supplier offered its high-end “Master Combustor” (MC) design, which runs at a minimum of 1,200°C, alongside the standard 1,000°C “Standard Combustor” (SC).
How the MC differs from the SC
| Standard (SC) | Master (MC) | |
|---|---|---|
| Minimum temperature | 1,000°C | 1,200°C |
| Minimum residence time | 0.3 s | 0.6 s |
| Ceramic lining | 100 mm | 150 mm |
| Temperature probes | Two, duty/standby | Six (one example: three heights with duty/standby) |
| Combustor and pipework | Carbon steel or stainless as option | 304 or 316 stainless steel as standard |
| Booster | Stainless impeller | Fully stainless steel, spark-proof |
The extra residence time and temperature mean a taller chamber. In the 1,700 m³/h example the shroud was 9 m high, in 316 stainless steel with a 150 mm ceramic lining fitted as blocks with no high-temperature surface fixings. Thermal turndown was 10:1. In the range specification, turndown was 5:1.
Why the extra cost buys little
The supplier’s advice was candid. If 1,200°C is specified, extra cost is being incurred for minimal extra advantage, and it makes sense where total quality is the requirement and cost is not restrictive. For a minimal-specification 1,200°C unit, savings can be had by not using stainless steel in the combustor and pipework. The booster impeller would need to remain stainless, though the housing could be carbon steel.
What stays the same
Both classes share the same control philosophy: combustion air louvre driven by a PID loop from the chamber temperature, a pilot burner lit by high-voltage spark (reliable for gas above about 20% methane), a self-checking UV flame sensor, and a PLC-controlled sequence. The main burner opens only when the pilot is stable.
Optional instrumentation lets the operator shut down on high oxygen (typically 8% in the UK and 6% in Germany) and watch methane and carbon dioxide to diagnose air ingress and imbalance in the gas collection system. Exhaust analysis for NOx, CO and sulphur oxides is also available, though on-line hydrocarbon measurement is described as usually expensive.
What to consider for your own project
- Start from the permit. UK guidance expects enclosed flares at 1,000°C with 0.3 seconds residence time. See the Environment Agency’s LFTGN05.
- Ask what 1,200°C actually buys you in your jurisdiction.
- Consider a minimum 1,200°C specification if the temperature is mandatory but premium materials are not.
- Check proving requirements. Our post on proving a 1,200°C flare by on-site test covers this.
FAQ
What does MC mean?
Master Combustor, the supplier’s high-specification enclosed flare range.
Why is residence time longer at 1,200°C?
The specification calls for 0.6 seconds, which requires a taller combustion chamber.
Can a flare be both 1,200°C and low cost?
A minimum-specification version avoids stainless steel in some parts.
Deciding on a flare specification?
Tell us your emission requirement and we will recommend the temperature class. See also ground flare or elevated flare?