CONTROLLING VAPOURS FROM OPEN SURFACE VESSELS

Abstract

Tests are described on four ventilation extraction systems—canopy hood, ‘push-pun’, rim and central slot—for removing toxic vapours from open surface vessels. As access was an important consideration, the central slot proved to be the most practical system. Initial design details for the central slot were obtained from Industrial Ventilation. A Manual of Recommended Practice. The rates of air flow were varied to establish the most efficient volume required to control the vapours effectively under all operating conditions. The reults indicate that lower volumes of air can be used for ‘undisturbed’ locations than those recommended by Industrial Ventilation. However, the volume flow rates required for ‘disturbed’ locations, i.e. those subject to cross draughts or similar conditions, are comparable to those outlined in Industrial Ventilation for ‘undisturbed’ locations. The paper provides design criteria for the central slot extraction system.