[GAUTAM RAY CHAUDHURY]

Gas weight and charged pressure of nitrogen cylinders available in Indian market? Can the gas from nitrogen cylinder bank be used for purging of Reheating furnaces (during emergency shut down) at a much lower pressure through pressure regulator and distribution pipework?

[talaniman]

We never purged with nitrogen, and during Emergency shut down the nitrogen must be turned off, what kind of furnace are we talking about? What is the application?

[GAUTAM RAY CHAUDHURY]

Do not agree to your reply.My query is regarding Reheating furnaces, operational in Steel plants, where fuel used are natural gas/mixed gas/converter gas etc.Purging with inert gas like nitrogen is essensial to remove the traces of fuel gas.

[talaniman]

I worked 30 years in a steel mill as a mechanic and I stand by my response as standard procedure for shutting down a furnace and venting with air for 30 minutes. I have worked on all types of furnaces from aneealing to galvanizine to normalizing and trust me, We never purge with nitrogen. That is why I ask the specific application and what type of furnace we are dealing with.

[GAUTAM RAY CHAUDHURY]

Please note that Nitrogen is used for purging the gas headers in various zones. Nitrogen is introduced after zone shut-off valves(remains closed during shut down).Discharge from the headers after purging the various zone heders is collected in the common header vented outside the roof of the building.This is regarding slab reheating furnaces , applicable for Hot strip mill.