Explain Inert gas system, how it works & where it used?

Working principle:

1.     Gas from boiler uptakes passes through two pneumatically operated, remote controlled, high temp. v/v’s.

2.     Then it passes through a scrubber into which SW is sprayed for cooling the gases to about 3°C above water temp. and scrubbing out soot particles and most of the sulphur oxides.

3.     Then the gases passes through a plastic demister.

4.     After scrubber the gas analysis is - 13% CO₂, 4% O₂, 0.3% SO₂, remainder N and water vapour.

5.     Two centrifugal blower provided, may one use at a time.

6.     The supply of cleaned dry inert gas at a press. of 1.2 to 6 KN/m² gauge press. is regulated by automatically controlled by by-pass v/v which is linked to main supply v/v. when the main supply v/v starts to close, the by-pass v/v begin to open and vice-versa.

Safety: 

1.     High temp gas v/v 

2.     Low water flow to seals and scrubbers. 

3.     Scrubbing tower overflow. 

4.     High oxygen content in gas. 

5.     High gas temp. 

6.     If inert gas temp. too high automatically del. v/v are closed & fan stopped.