3.2 Function of inert gas scrubber
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - Specifications and Manuals - Inert Gas Systems - 3 Function and Design Considerations - 3.2 Function of inert gas scrubber

3.2 Function of inert gas scrubber

  3.2.1 The purpose of the scrubber is to cool the flue gas and remove most of the sulphur dioxide and particulate soot. All three actions are achieved by direct contact between the flue gas and large quantities of seawater.

  3.2.2 Before entering the bottom of the scrubbing tower the gas is cooled by being passed either through a water spray, or bubbled through a water seal. Such a seal may also serve as the additional safety device to prevent any leakage of gas from the boiler uptake when the scrubber is opened up for inspection or maintenance.

  3.2.3 In the scrubbing tower itself the gas moves upwards through downward flowing water. For maximum contact between gas and water, several layers made up of one or more of the following arrangements may be fitted:

  • .1 spray nozzles;

  • .2 trays of “packed” stones or plastic chippings;

  • .3 perforated “impingement” plates;

  • .4 venturi nozzles and slots.

  3.2.4 At the top of or downstream of the scrubbing tower, water droplets are removed by one or more demisters which may be polypropylene mattresses or cyclone dryers.

Designs of individual manufacturers vary considerably.

A typical arrangement for an inert gas system


Copyright 2022 Clasifications Register Group Limited, International Maritime Organization, International Labour Organization or Maritime and Coastguard Agency. All rights reserved. Clasifications Register Group Limited, its affiliates and subsidiaries and their respective officers, employees or agents are, individually and collectively, referred to in this clause as 'Clasifications Register'. Clasifications Register assumes no responsibility and shall not be liable to any person for any loss, damage or expense caused by reliance on the information or advice in this document or howsoever provided, unless that person has signed a contract with the relevant Clasifications Register entity for the provision of this information or advice and in that case any responsibility or liability is exclusively on the terms and conditions set out in that contract.