Vacuum Catalogue - Edwards

12Page456This patented design offers many benefits over conventionaldeaerators and compact deaerator designs including the following:• Substantial height and weight reduction compared to conventionalvacuum stripping columns• May be used upstream of sulphate reduction membranes, since itcan operate without the addition of anti-foam chemicals• Unaffected by any motion of the installation, making it the preferredtechnology for FPSO applications• There is no reliance on catalysts, which have a limited life span andmay be poisoned• There is no requirement for storage and/or production ofhazardous combustible products such as methanol or hydrogen• Extensively field-proven technology, with over 50 units utilising thespray distributor supplied for water injection servicePacked Column DeaeratorsThis conventional design uses well-proven technology and remainsthe industry standard for both onshore and offshore applicationsworldwide.The design is suitable for both vacuum and gas stripping applicationswith corrosion resistant tower internals designed for foam retention,efficient liquid and gas phase distribution and redistribution, in orderto maximise mass transfer efficiency.Trace Gas Stripping DeaeratorsThis patented system combines vacuum stripping and inert gasstripping to offer a unit that operates under vacuum with the masstransfer process being assisted by a small quantity of inert gasadmitted into the deaerator column.This process allows highly compact deaerator columns to be usedwhilst the required vacuum pump capacity is substantially lower thanwould be associated with conventional vacuum stripping deaerators.Deaeration and the use of Sulphate RemovalSystemsEdwards is able to offer field proven designs for water injectiondeaerators, which are required to operate upstream of sulphateremoval systems. Such installations require that the deaerator mustoperate without antifoam agents since the use of such agents inincompatible with the membranes used in the sulphate removalsystem.Edwards has supplied units to replace conventional packed columndeaerator designs supplied by other manufacturers that have provedto be incapable of operating at the required design conditions withoutthe use of antifoam agents. Our ability to offer proven technologies,which provide enhanced mass transfer capability can enable existingdeaerator vessels to be re-used in order to minimise the cost anddowntime associated with the upgrade.Sulphate removal systems may be installed upstream of thedeaerator in which case antifoam agents may be used, however thislocation upstream of the deaerator column has many seriousdisadvantages, which include:• Materials of construction of the sulphate removal system must besuitable for service in contact with undeaerated seawater• Presence of oxygen in the seawater will increase the risk ofoxidation of the membranes and/or the possibility of aerobicbacteria or algae growth on the membranes• Additional precautions to ensure the removal of any hydrocarbonspresent in the water may be necessary prior to the sulphateremoval system to ensure that these do not contact themembranesDeaeration on Floating Production VesselsEdwards has considerable experience in the supply of deaerationpackages for use on floating production vessels, includinginstallations on FPSO's, semi-submersibles and on tension legplatforms.These production facilities require that the deaeration package isinsensitive to the motion of the installation and that the height andweight of the package together with the elevation of the center ofgravity above grade level are minimised.Our deaeration technology includes designs that are ideally suited tosuch floating production facilities, with references available for thesetypes of installations at locations around the world, in conditionsranging from offshore Canada to Equatorial Africa.Shop online at www.edwardsvacuum.com