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Inert Gas Generator Systems

Coldharbour’s engineers have over 50 years combined experience in the marine inert gas sector. As a result, the Sea Guardian™ Inert Gas Generator incorporates a number of innovative, patented elements aimed at achieving cleaner more stable operation and simaltaneously reducing maintenance costs and downtime.


Smaller overall footprint was a primary focus of the new design together with the capability to adapt to all current and foreseeable legislation regarding inert gas specifications in a wide range of applications.


The IGG has multi-fuel capability and the burner can be configured for use with a variety of fuels such as low sulphur MDO/MGO, LNG

and boil-off gas.   

Coldharbour engineers designed the Sea Guardian IGG with all the typical 'operating issues'  found in traditional systems engineered out. As a result the unit has no burner cone, no separate scrubber tower and no demister pad section.  Unexpected downtime is all but eliminated and Sea Guardian's design simplicity provides low maintenance, minimal downtime and inherently reliable operation.


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Inert Gas Generation brochure



  • No Vertical Scrubbing Section

  • No burner cone

  • No demister pad section

  • Zero soot

  • Low NOx and SOx emissions

  • Stable residual oxygen (0.2%)

  • Reduced maintenance costs

  • Simple to operate

  • Reduced downtime

  • Compact space envelopes



A specially developed venturi type burner is used incorporating 

axial flow staged fuel and low NOx atomisation.


The venturi burner ensures controlled, accurate, clean combustion across the full range of inert gas generator sizes including any turn-down regimes they may be operated under.


Although new to the marine inert gas generator sector, the burner is a Coldharbour development of a type originally designed for use in the power generation sector. As such, long in service life, lower emissions and reliable operation are inherent in the design



Older type burner technologies frequently struggle to achieve stable, low residual oxygen outputs whilst simultaneously generating zero soot.


Sea Guardian™ gas outlet content is typically 0.2% oxygen with zero soot as measured on the Bacharach scale.


Robust, stable operation is available with oxygen levels as low as 0.2% across the entire range of sizes from 500Nm3/hr. up to 20,000Nm3/hr. gas capacity, making Sea Guardiansuitable for chemical, LNG/LPG carriers and product tankers.

Reduced maintenance...


The new unit was engineered from the outset with all the typical operating issues designed out. As a result, the unit has no burner cone, no demister pads and no scrubber tower. There is nothing to clog and far less to corrode, so unexpected downtime is all but eliminated.

Smaller, no Scrubber Tower!


Hot gas from the burner is passed through an entirely new, compact, patented quench scrubber design which is based upon an inclined water curtain system incorporating a high temperature, corrosion resistant expanded metal mesh screen matrix.


The cooled gas then enters a swirl vane separator for the removal of any liquid droplets. The design is compact and elegantly simple.


Coldharbour inert gas generator systems use a Roots type blower of compact design. The blowers are selected for their low noise and low maintenance characteristics.


The Coldharbour IGG uses a programmable logic controller to give the required functions of control along with the designated selective acceptance of alarms. The instrumentation and control panels are generally located in the engine room, cargo room and bridge. Special requirements can be incorporated into the system.

The Coldharbour deck water seal is a wet type design with an external seal pipe for added safety. Water is displaced during normal gas flow forming a semi wet seal. Entrained water is expelled by swirling the gas in the vessel and passing it through an integral demister. Alternatively, where appropriate, double block & bleed valves can be supplied.


The Coldharbour pressure/vacuum breaker provides the final protection within the system by releasing excessive pressure or vacuum from the cargo tanks. This ensures that the tank design conditions cannot be exceeded. The PV breaker is designed to be fail safe in operation.


Coldharbour gas delivery and control valves are of the butterfly type with bonded rubber linings and corrosion resistant discs and shafts. Where remotely controlled, the valves use double acting actuators.

Sea Guardian has been comprehensively tested over a number of years with no failures, blockages or operating issues and currently holds a Lloyds Register Type Approval certificate confirming performance parameters for the unit.