Pressure reduction and increased volume

[asami58]

Hi. Can someone help me please.
I have a steam generator which is designed to operate from natural gas with pressure of 2000 -4000 mmAq. It consumes a volume of 71 Nm3/h of the gas. I want to operate it on Liquid Petroleum Gas (LPG-Propane). The problem is that LPG is available in cylinders at a pressure of 150 to 200 psi. I used a pressure regulator to bring down the pressure to required limits, but the system locks out because it is not getting sufficient volume of the gas. How can I provide it with the required volume and pressure from an LPG cylinder?

 

[russ_watters]

Welcome to PF.

Your regulator must be set too low: propane has a higher energy content per unit volume than natural gas so you actually need less of it. So actually, in addition to the regulator, you may need a smaller orifice to allow less flow at the same pressure. See if your manufacturer has a conversion kit.

 

[asami58]

Hi Russ
Thanks for the reply. Firstly, the manufacturers (Booster Boiler Co Ltd, Korea) don't have a conversion kit. Secondly, i did use a smaller orifice (the LPG cylinder valve allows for about 0.25" nozzles). Originally, the unit requires a 2" dia inlet pipe for the gas, I used a 0.25" nozzle. It allows the pressure to be regulated, but somehow the volume isn't sufficient. The air/gas mixture not being optimum, the flame is not blue enough and the flame detector gives a lockout. The company has advised I use multiple cylinders in parallel, which brings me to the point of wanting to know how to regulate the combination?