2 replies to this topic

[Ankit_Kumar]

Hi there

 

I need to calculate Nitrogen flow required to dilute methanol vapors to avoid LEL value.

Appreciate if somone can share the calculation. Methanol flow is 100 Nm3/hr while LEL is 6%.

 

Regards

 

[MrShorty]

The question seems so simple that I wonder if there is more to the question than is being given.

 

Assuming it is as simple as suggested, start with your basic definition of concentration as fraction/per cent:

 

x(fraction)=x(MeOH)/x(total)

0.06=x(MeOH)/x(total)

 

The first main questions is regarding the "units" on the LEL -- is it given in mass fraction, mole fraction, or volume fraction? For your purposes, are you going to assume that volume fraction and mole fraction are the same?

 

Once you decide what units you need to use, it should be as easy as plugging the amount of methanol into the equation and solving for x(total). Then, back out from that quantity how much needs to be nitrogen.

[breizh]

Ankit_kumar ,

 Consider the document attached , in particular the first paragraph about threshold to maintain to be "safe"

 

Good luck,

 

Breizh