Waste Gas Flares

• Wastewater Treatment Plants - Biogas/Bio-gas Flares, Digester Gas Flares
• Chemical Processing Industry (CPI) and Hydrocarbon Processing Plant Waste Gas Flares
• Landfill Flare Systems
• Tank Farm Waste Gas Flares
• Oil and Gas Production Plant Flares
• Food Processing Plants
• Any application that calls for the control of VOCs, CO, BTEX, H2S, and most other types of waste gas

• Cost Competitive - Capital, Operation, Maintenance
• Skid Mounting allows for simple, low cost installation
• VOC Destruction Efficiency is guaranteed up to 99.99%+
• Hidden Flame
• MRW Proprietary Flash-back resistant burners for waste gas flares that have waste gas in the explosive range
• MRW uses a proprietary staged-combustion design that allows for superior mixing of waste gas, air, and fuel and minimizes NOx creation
• MRW designed specialty burners and waste gas injection nozzles
• MRW Proprietary pilot - Fast and Reliable Ignition
• Exceptionally low CO
• Exceptionally Low NOx - MRW can meet the most stringent requirements
• Safe Design and Operation
• Guaranteed DRE and Operation
• Fully Integrated Burner Management System
• Over 100 years experience designing waste gas enclosed flares and experience with over 1,000 installations worldwide

Enclosed Stack - Combustion Chamber

MRW enclosed flare systems use a vertical, cylindrical, and self-supported refractory lined stack. The flame is completely hidden inside the combustion chamber. The refractory used is designed for cold start-ups. The refractory is designed to withstand shrinkage from exposure to high temperatures.

Destruction efficiencies of up to 99%+ are achieved by using an enclosed flare.

The stack includes lifting lugs for easy in field installation. MRW uses a special type of refractory attachment system designed for exposure to extremely high temperatures and is resistant against corrosion.

For waste streams that are in the explosive limits, the enclosed stack includes an MRW Anti-Flashback burner assembly to allow for safe operation and stable combustion at high and low vapor rates. For situations where strict NOx requirements exist, MRW uses a proprietary staged combustion burner and injection design.

The temperature is controlled via quench-air dampers that monitor the amount of air into the combustion chamber. Thus, fuel usage is controlled by maintaining a set point temperature usually of 1600F to 1800F depending upon plant needs, type of facility, and environmental requirements.

Pilot and Burner

MRW manufactures continuous and energy efficient pilots designed for reliable flame stability during any operating condition including the harshest weather and extremely high wind speeds. Our pilot burners are fabricated out of 309/310 stainless adding extended life to the pilot burner assembly.

The spark ignition rod is strategically placed in the tip for rapid ignition of pilot fuel gas. This design is based on experience from experience with over 1,000 flare installations. An air/fuel gas mixer is attached to the pilot burner assembly to allow for a combustible mixture at the pilot burner tip. No field welding is required as mounting brackets allow for easy field installation. The MRW local control panel powers the ignition transformer for automatic ignition of the pilot.

The enclosed stack includes an MRW Anti-Flashback burner assembly or MRW staged combustion burner to allow for safe operation and stable combustion at high and low vapor rates. MRW anti-flashback burners work to distinguish a flashback the same way a detonation/flame arrestor does by absorbing the heat of the flame into an element especially designed for distinguishing flame propagations.

MRW pilots and ignitions systems are proven to be reliable, fast, and easy to operate and maintain. Our pilots are designed for continuous and intermittent use in adverse weather conditions and extreme wind speeds. MRW pilots increase the reliability and performance of the flare system by providing flame stability in any operating conditions.

MRW designs extremely energy efficient pilots using as little as 50SCFH of fuel gas. Our local control panel powers the ignition transformers and automatically ignites/re-ignites the pilots.

Ignition of the pilot can be done via:

• Manual Ignition - the pilot is manually ignited via a push-button activation.
• Auto Ignition - a spark igniting device and ignition transformer ignites the flame front.
• Auto Re-Ignition - the flare tip pilot temperature switches automatically trigger the ignition transformers to re-ignite the flare tip pilots upon loss of flame.
• Remote Ignition - the flare system to be capable of automatic startup and shutdown based on either local or remote initiation.

Detonation Arrestor or Liquid Seal (Optional)

If waste gas fumes contain oxygen, are in the explosive range, and/or there are extended pipe runs or multiple bends in pipe, a detonation arrestor may be used to prevent flashback upstream of the flare system. This is an important flashback prevention device but it should never be the only line of defense to mitigate a flashback. MRW uses detonation arrestors approved by the US Coast Guard. In some situations, a liquid seal with a fluid barrier can be used in lieu of a detonation arrestor to keep air from penetrating the flare header.

Control / Ignition System

MRW can design our control systems to meet any electrical classification. Our control systems utilize state-of-the-art design techniques and technology to obtain optimum service potential. If you have a preference as to what type/brand of control system, we are happy to accommodate your needs.

The control system automatically purges the combustor, completes flare permissives, ignites the pilot, initiates the blower, and enriches the waste gas stream. The control system has several safety shutdowns indicating an error in the system operation. MRW flare systems are designed for numerous safety and shutdown precautions. Our systems will detect and shutdown if the following situations occur:

• High liquid level
• High Temperature on Detonation Arrestor
• Loss of Pilot
• Excessive high stack temperature
• Loss of permissive signal from loading rack
• Manual operator shutdown

Knockout Drum (Optional)

Knockout drums are provided in situations where liquid separation is likely in the waste stream. A knockout drum will collect any liquid in the waste stream before reaching the flare system. knockout drum is especially important if substantial cooling of heavy liquids is expected. If the liquid is corrosive, MRW uses non-corrosive materials of construction. A level gauge and drain connections are built into the knockout drum.

Other Optional Equipment

• Ratio Control - used to save fuel gas when multiple sources are routed to one flare system and may flow at different times, not at all, or at the same time.
• Temperature Recorder - some terminals or tank farms may require proof of operating temperature via a temperature recorder. This is supplied as an optional adder as not all terminals require this as proof of operation.
• Skid Mounting - all of our terminal flare systems can be skid mounted in order to simplify field installation and reduce costs. The control skid is complete with the following components mounted, piped, and pre-wired:
  • Local Control Panel
  • Pilot fuel gas valve train
  • Enrichment gas valve train
  • Detonation Arrestor with thermocouples
  • Knockout Drum with level gauge.
  • Auto-block valve with limit switches.
• NFPA Compliant - this would include self checking flame scanner, double blocks and bleeds, and high/low pressure switches as required.
• Motor Starter

MRW uses technologies that are based upon over 30 years of advanced, real-world combustion experience by each of our principal engineers. MRW engineers have experience with over 1,000 combustion equipment installations. Applying this experience, we are able to offer technology only a few companies in the world can accomplish. The following components are the heart of our premium enclosed flare designs.

MRW Split-Staged Combustion System

Split-Staged is a proprietary MRW burner arrangement and waste gas injection design that allows us to utilize our staged-combustion technology. This technology allows for correct burner placement within the combustion chamber and staging of the waste gas, air, and fuel gas around a core burner. Staging of the waste gas, air, and fuel gas allows us to achieve superior mixing for very high VOC destruction, CO destruction, and Low NOx creation while maintaining a highly stable burner under both low and high firing rates.

In effect, MRW staging technology "splits" the flame into several "smaller" flames. These smaller flames are built around one "core" burner flame. The benefit of this technology is it produces exceptionally low NOx levels by maintaining low peak flame temperatures as well as excellent mixing with waste gas, air, and fuel gas. This allows us to maintain an extremely stable burner under both low and high firing fates. Staged combustion allows for correct mixing of waste gas, destruction of CO while producing as low as .04 lb per mmBtu NOx or less.

In addition to the required mmBtu burner size, when utilizing staged-combustion the burners must be in the correct position and the ratio of air, fuel gas, and waste gas must be optimized in order for the thermal oxidizer or enclosed flare to work effectively and efficiently. In some cases, multiple burners may be necessary to reach optimum performance.

MRW Split-Stage Waste Gas Injection Nozzle System

This is a proprietary MRW waste gas injection system that "spins" the waste gas through a proprietary mixing nozzle design, thus creating a very turbulent environment as the waste gas is introduced into the combustion chamber. This is critically important to achieving correct mixing and keeping fuel costs to a minimum. This is customized for each application and depends upon many factors including type of waste gas stream, heating value, oxygen content, temperature requirements, etc.

NOTE: Regardless of temperature or residence time, without correct mixing and injection of waste gas, air, and fuel gas a thermal oxidizer will not adequately destroy VOCs or CO. Furthermore, without correct mixing a thermal oxidizer may not be able to reach temperature requirements.

MRW Core Burners

Unlike most thermal oxidizer and enclosed flare manufacturers, MRW designs and manufacturers our own high efficiency burners. Our burners are a result of each of our principals` 30+ years experience in the combustion industry, extensive research and development, and real-world applications going back to the 1960`s. MRW core burners are able to produce as little as .04 lb. NOx per mmBtu or less. MRW uses burners that are extremely stable under both low and high firing rates.

MRW Anti-Flashback Burners

MRW anti-flashback burners work to distinguish a flashback the same way a detonation/flame arrestor does by absorbing the heat of the flame into an element especially designed for distinguishing flame propagations. MRW Anti-Flashback burner assemblies allow for safe operation and stable combustion at high and low vapor rates. These types of burners are used in loading terminal vapor control flares (combustors) and applications where the potential exists for vapors to be in the explosive range.

MRW Combust-Equate

The MRW Combust-equate system is a computer program utilizing combustion formulas derived from our extensive combustion experience going back to the 1960`s. It allows for extremely accurate combustion chamber sizing, burner sizing, burner type(s), residence time, temperature requirements for auto-ignition (destruction) of VOCs and CO, combustor shape, oxygen requirements, and method and ratio of air, waste gas and fuel gas introduction into combustion chamber.

MRW Pilots

MRW manufactures continuous and energy efficient pilots designed for reliable flame stability during any operating condition including the harshest weather and extremely high wind speeds. Our pilot burners are fabricated out of 309/310 stainless adding extended life to the pilot burner assembly.

The spark ignition rod is strategically placed in the tip for rapid ignition of pilot fuel gas. This design is based on experience from experience with over 1,000 flare installations. An air/fuel gas mixer is attached to the pilot burner assembly to allow for a combustible mixture at the pilot burner tip. No field welding is required as mounting brackets allow for easy field installation. The MRW local control panel powers the ignition transformer for automatic ignition of the pilot.