Enclosed vs. Open

Enclosed

vs.

Open Flares

This Paper Considers The Benefits Offered Using The Two Types of Enclosed Flare System’s Versus an Open Flare System

The Open Flare System There is information out there that is being used as an efficiency of combustion of landfill gas on an open flare system of 98%. This is not correct for landfill gas. The test was with a flammable gas Propylene, (CH3 CH: CH2) which is derived from petroleum hydrocarbon i.e. Propane Gas referencing (EPA 430-R-99-012 August1999) and in our opinion should not be used for landfill gas. It is almost impossible to read an open flare burning landfill gas. All open flares should be outlawed, as in the rest of the world and only used as a temporary flare for emergency use. It should be rated at maybe 5% not 98% efficient and should not be used for carbon credit trading, as it requires verification of emissions. This has all the hallmarks of pumping out methane gas that has not been burnt in great amounts with no control over the combustion process whatsoever. This type of system should never be used. It’s a hazard and a contributor to global warming and acid rain.

The Fixed Tip Enclosed Flare System Most of them are an open flare with a shroud around them. These are more efficient than an open flare and can be controlled to a point. The drawback is they have a fixed tip (exit orifice) so can only be set to one given flow rate. With this design type, the flow rate, once the parameters change, can be as bad as open flares. Any engineer will tell you that a fixed tip has to be sized for a given flow on this type of flare. They normally have a turn down 5-1 which means you have to manually turn a fixed tip off and on. The combustion efficiency of this type of flare will always be questionable because whenever the site condition changes, which it does all the time, it needs constant manual adjustments in order to comply with regulations and in order to be acceptable for carbon credit trading. In no way can this type of fixed tip flare system be 99% efficient. With no site parameters ever changing, it is impossible to achieve site condition without changes taking place all the time.

The Hilo Enclosed Sonic Flare System This flare does not use a fixed tip, it uses a variable tip which is controlled by PLC which adjusts to give optimum combustion at any flow rate and will self adjust to field conditions. It is proven to be the best flare system on the market today and is based on the ideal combustion process for landfill gas and does not rely on the design sizing of a fixed tip as in the above so called enclosed flare. This system is ideal for carbon credits because it can verify exhaust emissions greater than 99.9% at any flow rate and has a proven track record of doing so in more than just the landfill industry. Customers should ask any flare manufacture to prove that they can reach the percentages that they are saying on landfill gas and not reference information that does not have anything to do with landfill gas (as above when test are done using a different type of gas, in this case Propane, which has no relevance to landfill gas whatsoever).

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Useful Info

Hydrogen Sulphide (H2S)

Enclosed Vs. Open flare systems