PURGING AND FLARING

The new GEA Flare Unit is based upon the successful 100mm SPU purge vent unit widely used by natural gas contractors and National Grid. It includes a flare stack with automatic continuous ignition to burn off large quantities of LPG or Natural Gas. The flow rate is dependant upon line pressure, which can be up to 2 bar with the correct injector and hose.

The burner is protected by an in-line flame arrestor and has a 110V rated continuous spark igniter to ensure that the flame is not blown out in high winds. The kit comes complete with 10m of High Pressure BS 3212 hose or Low Pressure Natural Gas hose.

The portable unit enables LPG and NG contractors to safely burn off Natural Gas and heavier than air LPG from pipework and pressure vessels under controlled pressure conditions without risk of the collection of clouds of flammable gas. The flare unit can also be used to depressurize systems prior to venting. The ignition system requires an 110V ac supply.

The Flare Unit has been under test by Calor and BP LPG and the well-proven burner head has recently been used on site for flaring natural gas from 315mm PE pipe and from 20 bar pressure vessels on a CHP installation.

100m of 150 mm of NG pipe, if vented without flaring, has a CO₂ = equivalent of 90kgs! 1,886km of cast iron pipe replaced last year by National Grid contained vented NG having an estimated CO₂ equivalent of 4000kgs. Flaring could have reduced the damage to the environment.

GEA produce a range of purging vent units and purge fans for the gas industry for those contractors working within the strict regime of IGEM code UP/1. GEA can also provide training on the use of purging equipment and, if required, on-site support.

Additionally, GEA produce a low cost pipe calculator for simplifying sizing pipework and performing the complicated calculations required by UP/1.

Flaring of purge gases

It is well recognised that venting natural gas or LPG into the environment is a potential Greenhouse Gas issue.

LPG being heavier than air also poses additional hazards when venting and to date an economical flaring system that is easy to use and transport has not been readily available.

The new GEA flare system enables gas to be burnt off at a controlled rate with an acceptable size of flame that does not pose safety hazards to the purging operative or nearby buildings.

The continuous spark ignition system ensures that the gas continues to be burnt as the purge using air or nitrogen progresses. As with other GEA Purge Units, this

package comes complete with hoses, flame arrestors, instantaneous reading flow meters, valves and test points.

IGEM UP/1 includes procedures to minimise such venting but flaring or burning-off is in many cases a real alternative option. This is especially so when venting

down LPG pipework, LPG tanks prior to removal from site, gas compressor pressure vessels associated with CHP installations and pipework.

The larger size of flare unit has two burners and is for very large flaring operations such as in CHP installations.

The GEA Flare Burner units can be used with natural gas or LPG. The opportunity to safely burn-off the venting LPG provides added security to the operative since LPG being heavier than air could collect at ground level and any fire could lead to serious burns!

The resultant Carbon Dioxide from the combustion is also some 70 times less polluting [GWP] as a 'greenhouse gas' than the LPG or NG.

The Standard Flare Unit is based on the GEA SPU Purge Box, shown right, Larger systems can be flared with the MFU Purge Box with a double Flare Stack.