INS Talwar is an Indian warship. Its name means “Sword” in Hindi. INS Talwar is a multirole frigate and true to her name, has participated in various operations and exercises since her commissioning.
Talwar was built by the Baltiyskiy shipyard and was launched in May 2000. The ship was commissioned formally into the Indian Navy on 18 June 2003. INS Talwar arrived home at Mumbai’s Naval Dockyard on 12 August 2003, after a long journey from St. Petersburg.
INS Talwar was under maintenance at Naval Dockyard, Mumbai, in coastal climate. INS Talwar was facing problem of frequent turbines failure due to corrosion during refit/ repair work. Each gas turbine (with casing DIA 2.5 meters and total length of approx. 64.0 meters ) was having swept volume of approx. 100 cu.mtr each, were kept in bulk head area of ship on either sides of the ship below upper deck. Refit / repair period was planned for minimum 01 year.
TDS Airgineers visited the dockyard and inspected the site. The culprit was high humidity. Humidity is always high at coastal areas. Since the refit work was undergoing near the sea atmosphere, RH was always more than 80% and temperature around 32°C. Due to which there were frequent turbine failures.
After discussion with the team TDS Airgineers suggested to preserve Ship Gas Turbines under dehumidified conditions.
The general concept behind the use of temporary dehumidification or climate control equipment is to create an environment that reduces the relative humidity in the space below 50%.
During refit work through out the year both Gas Turbines were kept intact without any corrosion inside due to condensation. RH was maintained below 20% at outlet of the Dehumidifier which continuously maintained 34% RH inside turbine.
We considered 10 air changes/ hour to design dehumidifier on open passage of ship upper deck and fed dehumidified air in open loop through openings even in H.I. casing.