Landfill sites don’t always have the luxury of unlimited vertical space. Proximity to airports, residential areas, planning restrictions, or simple site logistics can mean that a tall, traditional flare stack simply isn’t an option. The RB Class flare stack, engineered by Organics, was designed specifically to solve this problem — delivering environmentally sound, reliable combustion of landfill gas in a significantly lower profile than conventional systems.
What Is the RB Class Flare Stack?
The RB Class is a low-height combustion system for burning off landfill gas safely and efficiently. Rather than relying on tall shrouds to achieve the retention time and temperature needed for complete combustion, the RB Class uses an extended-diameter flare shroud with increased flame distribution across the shroud’s cross-sectional area.
This design reduces the heat-flux to area ratio, which means the system can maintain elevated combustion temperatures and extended gas retention times within a noticeably shorter combustion chamber — ideal for height-restricted sites.
Solving the “Lazy Flame” Problem
A shorter shroud naturally produces a lower head for air inspiration. On its own, this tends to encourage long, “lazy” diffusion flames — a phenomenon that can compromise combustion quality and emissions performance.
Organics’ engineering approach counters this directly:
The RB Class uses higher pressure at the burner to achieve turbulent diffusion flame combustion, avoiding the symptoms of lazy diffusion flames.
By increasing burner pressure, the system promotes the turbulent mixing needed for thorough, non-visible combustion — even within a compact chamber footprint.
Key Features
- Low-height combustion system for use where vertical clearance is restricted
- Automatic flame temperature control
- Non-visible combustion
- 1,000°C minimum design temperature
- 0.3 seconds minimum retention time (standard specification quotes 0.6 seconds — see table below)
- Emissions control compliant with UK, European, and US standards
- Booster turn-down to zero flow without surging
- Optional fully stainless steel construction
- Skid-mounted for ease of relocation around site
- Duty/standby thermocouples for reliable temperature monitoring
- Shroud lining using ceramic blanket blocks with no hot-surface fixings
- Optional instrumentation for flow rate and gas concentration measurement
- High-reliability landfill gas pilot burner — no propane required on site
Technical Specifications
| Parameter | Specification |
|---|---|
| Flow rate range | 100 to 15,000 m³/hour |
| Pressure rise across gas booster | 150 mbar |
| Flame temperature | 1,000°C minimum |
| Retention time | 0.6 seconds |
| Minimum methane concentration for combustion | 25% |
| Standard inlets | 2 flanged inlets (additional available on request) |
| Flow control | Chemical-duty butterfly valves |
| Pipework finish | Hot-dip galvanised to industry standard |
| Burner material | High-temperature stainless steel |
| Flame arrestor location | Gas booster inlet and outlet |
| Flame detection | Self-checking UV sensor |
| Standard colour | Battleship Grey (or customer specification) |
With a flow range spanning 100 to 15,000 cubic metres per hour, the RB Class scales from small closed sites to large, actively gassing landfills.
Standard Equipment Included
Every RB Class flare unit is built with a comprehensive set of process safety and control features as standard:
- Dewatering condensate knockout pot prior to the gas blower
- Automatic drain-leg to remove condensate without shutting down the flare
- Level switch in the knockout pot to detect high condensate levels
- Flame arresters on both the inlet and outlet of the gas blower
- 150 mbar total-head blower
- Back-swept blower blades, enabling turn-down to zero flow without surging
- Automatic slam-shut valve on the flare feed line
- Manual flow control and isolation valves on the blower inlet and outlet, allowing flow control via pressure, suction, or both
- Orifice plate flow meter with manometer readout or calibrated differential pressure gauge
- High-reliability landfill gas pilot burner (eliminates the need for on-site propane)
- Ceramic blanket block shroud lining with no hot-surface fixings exposed to the flame
Hazardous Area Compliance and Control Systems
As with all Organics landfill gas flaring equipment, the RB Class is designed for outdoor, open-air use. Because landfill gas presents a hazardous atmosphere, all electrical equipment must be either Intrinsically Safe (IS) or built to Zone II hazardous area standards. Where a site’s risk assessment demands it, the plant can also be constructed to Zone I standards, although this is not typically required for a standard landfill environment. For more background on hazardous area classification, see ATEX and hazardous area zoning.
Control panels are supplied with a 20% expansion factor, leaving room to add further control equipment down the line. For example, a modem can be retrofitted to enable remote alarm notification or connection to the internet — an extension unit connects to the plant controller via an RS232 port to manage the link to the Public Switched Telephone Network. The panel and standard wiring are designed to accommodate this upgrade without redesign, allowing the root cause of any alarm to be isolated in the plant controller logic and reported remotely.
Typical Applications
The RB Class is well suited to:
- Landfill sites with height restrictions (e.g. near airports, residential zones, or under local planning constraints)
- Sites requiring skid-mounted, relocatable flare equipment
- Operators seeking stainless steel construction for corrosion resistance in demanding environments
- Projects needing compliance with UK, European, or US emissions standards for landfill gas combustion
Key Takeaways
- The RB Class flare stack delivers reliable, high-temperature landfill gas combustion in a low-height footprint, using an extended-diameter shroud design.
- Higher burner pressure counteracts the “lazy flame” tendency of short shrouds, ensuring turbulent, non-visible combustion.
- The system handles flow rates from 100 to 15,000 m³/hour, with a minimum design temperature of 1,000°C and a 0.6 second retention time.
- Comprehensive standard features — condensate management, flame arresters, surge-free blower turn-down, and a propane-free pilot burner — reduce operational complexity and maintenance burden.
- Control panels are built with expansion capacity for remote monitoring and alarm reporting.
If your site faces height restrictions or you’re evaluating flare options for a new or upgraded landfill gas management system, get in touch with our team to discuss whether the RB Class flare stack is the right fit for your project.