Shipping lines are increasingly installing Inert Gas Generation systems on board as the cost of these systems is very reasonable and the benefits far outweigh the risks of not having one. The Inert Gas System is the only safe way to prevent fire accidents on ships and oil tankers. Sanil P Joseph, Electrical Officer at Merchant Navy details out how Inert Gas System works in oil carriers.
Oil tankers carry oil of different grades and quality, having property to produce flammable vapours and gases when loaded for transportation. Even with no cargo on board, there can be harmful flammable gases present in the hold. When the vapour produced by an oil cargo is mixed with certain concentration of air primarily containing oxygen, it can result in explosion which results in damages to the property, marine pollution and loss of life. For safety against such explosion, Inert gas system is used on board. It can be through a separate inert gas plant or flue gas produced by ship’s boiler.
The inert gas system in an oil tanker prevents the back flow of the cargo gas to the machinery space and the atmosphere. The gas emitted from the oil is very hazardous. By inerting we keep the oxygen percentage of the gas well below the LEL (lower explosive limit).
(Read the full part of this article in the March issue of Safety Messenger Magazine 2015)