uk water treatment engineers specialising in design ... · uk water treatment engineers...

UK Water Treatment Engineers Specialising in Design, Manufacture, Project Management,

Servicing and Commissioning of Water Purification Systems Worldwide

Sand and Carbon Filters

Water Softeners

Dealkalisers

Demineralisers

Reverse Osmosis

AWE carry out complete projects including all thenecessary civil, mechanical and electrical workrequired for a ‘turnkey’ contract.We will adviseclients at the scheme conception stage of a projectand then carry a project through the design andplanning stages, into fabrication in our localworkshops.We can then arrange transport, siteerection, installation and commissioning. AWE canalso provide after sales services contracts onrequest.

Project Management and Control

Since inception in 1974 the company’sexpertise has placed AWE Ltd as a leader inthe UK and worldwide in the field of waterpurification and water purification systems,including water softeners, demineralisation,reverse osmosis and dealkalisation plants.

AWE’s experience in water purificationsystems over the past 30 years extends to alltypes and sizes of water treatment plant fromdomestic water softeners to the supply and

installation of large demineralisation plants toall industries from power stations through tothe brewing and beverage industries.

AWE is an ISO 9001:2000 registeredcompany and all of its water purificationsystems are of the highest quality anddesigned to exacting standards, includingpressure vessels manufactured to PD 5500and control panels to the latest IEEregulations.

Introduction

The Technology-in-Progress Approach

With an in-depth knowledge of all aspects ofwater treatment, we place great emphasis onthe supply of reliable, efficient equipment,professionally designed to suit each specificapplication.

AWE’s flexible design strategies allow a clientto standardise equipment throughout theworks without losing the cost advantage of astandard plant.

Designs are constantly being revised toincorporate the ever increasing range of newmaterials and products available to ourengineers.

This ‘technology-in-progress’ approach enablesour clients to keep one step ahead of thecompetition.When required, we also provideinstallation and commissioning of ourequipment and arrange after sales servicecontracts.

2 S a n d a n d C a r b o n F i l t e r s W a t e r S o f t e n e r s

AWE Limited offer comprehensive service and maintenancecontracts for all types of water purification equipment.

Additional services offered by AWE Ltd include the following:

• Filter sand media removal, disposal andreplacement

• Carbon media removal, disposal andreplacement

• Ion Exchange media removal, disposaland replacement

• Automation of existing manual plant• Repair / replacement of pressure vessels

and storage tanks• Modifications to pipework• Valve repair and replacement service• Pump repair and replacement service• Eductor / ejector repair and replacement

service• Supply, install and commission bulk acid

and caustic chemical tanks

AWE has contracts for clients who are based across the length andbreadth of the United Kingdom utilising the skills of our strategicallyplaced water treatment engineers.

Spares and Services

3D e a l k a l i s e r s D e m i n e r a l i s e r s R e v e r s e O s m o s i s

Coagulation/Settling Vessels are used for a wide variety ofapplications which require the addition of chemicals to thewater being treated to form precipitates and settlesuspended solids in the raw water. Such applications includethe addition of lime to raw water in the cold lime softeningprocess, which also reduces the alkalinity of the raw water,and the addition of lime or other alkalis to effluents to effectprecipitation of insoluble hydroxides.

The raw water is chemically dosed and, over time, thesuspended solids precipitate out and settle at the bottom ofthe coagulator whilst the clean water is collected at the topof the vessel.

Coagulation is the primary step in treating poor qualitysurface water before other forms of treatment such as ionexchange, reverse osmosis or even filtration can be used. It isalso used extensively in the soft drinks industry wherealkalinity reduction is required. AWE coagulators arespecifically designed for each application taking into accountraw water quality and equipment requirements.

Coagulation

Ion Exchange Equipment

Ion Exchange forms the basisof several types of treatmentwhich although utilising verysimilar equipment, by the useof different resins andchemicals, produces verydifferent quality waters.

The heart of any ion exchangeplant is the resin, which isspecially selected by AWE togive the required capacity andquality of treated water. AWEonly use the best quality resinsto ensure optimum and longlasting performance.

Because of the wide choice ofresins now available, AWEhave designed and suppliedion exchange equipment tocarry out functions notcovered by the informationdocumented in this literature.

Applications such as organicscavengers or traps forremoving organics or colourfrom water, nitrate removalusing special nitrate specificresins are becoming morecommon as water suppliesdeteriorate and industrialstandards increase.


These filters contain a special iron removal media.The media catalyses the oxidation of the iron in thewater which is then filtered out on the media.Backwashing of the filter removes the iron andrejuvenates the media. Iron removal filters are usedsometimes to protect ion exchange and reverseosmosis equipment, and sometimes separately, wherethe unpalatable taste and staining characteristics of iron is causing a problem.

Sand Filters

Iron Removal Filters


Moderately turbid waters can be clarified inthe simplest way by being passed through amedium such as a bed of graded sand.Thedegree of filtration depends on the grainsize of the sand used in the filter and this inturn is a function of the filtration rate usedin the filter vessel.The gradual build-up ofthe suspended solids in the filter raises thebackpressure and when the resultingpressure drop from the filter inlet to thefilter outlet reaches a predetermined level,the filter has to be cleaned by backwashing.

Backwashing is carried out by reversing theflow through the bed, thus lifting andexpanding the filter bed.The grains of sandcollide with each other and, in doing so, freethe accumulated suspended solids which areswept away to drain with the backwashwater. Sometimes air is injected prior tobackwash water to break up the bed.Thisreduces the flow rate of backwash waterrequired to effectively clean the filter bed.

Selection of sand filter sizes can only beperformed after careful examination of thewater analysis, flow rates and required purityof filtered water.

These are similar in designto sand filters, but use abed of activated carbon asfiltration media.Theactivated carbon has theproperty of being able toremove chlorine, odour,colour and organic matterfrom water.They are oftenused ahead of deminer-alisation and reverseosmosis equipment inorder to pretreat thewater.

Base Exchange softeners utilise cation resin to changescale-forming calcium and magnesium ion (totalhardness) into non scale-forming (soft) sodium ions.When the resin is exhausted it must be regeneratedwith a common salt solution.

Softeners are the most common type of ion exchangeequipment and find numerous applications in the UK,where the majority of the water is hard.

Applications:• Basic boiler water treatment• Laundries• Bottle and dish washing machines• General hot water duties where scale

formation could give rise to problems

AWE have various ranges of softeners.The ‘packagedplant’ range covers the domestic up to the smallindustrial size.These can handle hardness levels up to600 mg/I and flow rates up to 50m3/hr.The vesselsare manufactured from GRP and regeneration is fullyautomatic via a multiport valve.The industrial rangehandles all flow rates in excess of 50m3/hr and utilisescarbon steel pressure vessels, industrial valves andmicroprocessor controlled regeneration. Automaticregeneration is normally initiated by time clock orwater meter.Where necessary, AWE can supply arange of sizes of bulk salt saturator tanks.These arefabricated in GRP, are suitable for indoor or outdooruse and take salt deliveries directly from road tankers.

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Softeners

Carbon Filters

S a n d a n d C a r b o n F i l t e r s W a t e r S o f t e n e r s

Dealkalisers use weak cation resin toconvert the bicarbonates (alkalinity) inthe water to carbonic acid.To removethe carbonic acid, the water is passedthrough a degasser tower.Whenexhausted, the resin is regenerated usingacid.

The total dissolved solids (TDS) contentof the water is reduced by an amountequivalent to the alkalinity present in theraw water and therefore a partiallydemineralised water is produced.This isvery useful as the capital and operatingcosts of the treatment are very low.

Typical applications are for pretreatmentof boiler feed water where lowering ofthe feed water TDS enables the boilerblowdown to be reduced. Also,dealkalisation by ion exchange is findingwidespread acceptance and use in thesoft drinks and brewing industry. Both ofthese industries require low alkalinitywater for certain products and dealka-lisation by ion exchange is a clean, easilyautomated, low cost process with manyadvantages over the more traditionalcold lime treatment or direct acidinjection methods.

AWE have two ranges of dealkaliserssimilar to the range of base exchangesofteners.The small ‘packaged plant’range utilises special vinyl ester pressurevessels and all plastic multiport valves.The large industrial range featuresspecially lined mild steel pressurevessels, individually lined valves andpipework and microprocessor control.Automatic regeneration is normallyinitiated by a pH controller.

Dealkalisers


Demineralisers use both cation and anionresin to remove dissolved solids in the water.The cation resin must be regenerated usingacid and the anion resin using caustic orbrine.

A wide range of demineralisers is availableincluding our D series, which has two ionexchange columns containing separate bedsof cation and anion exchange resins, M seriessingle column mixed bed demineralisers, inwhich the cation and anion resins are mixed,and variations of these types.

In cases where flow rates and daily consumptionfigures are high, selection of the type of deminer-alisation equipment best suited to the applicationbeing considered is arrived at by carefullyexamining several variations of demineralisationsystems and several types of resin. Pretreatment ofthe water to be demineralised is often necessary incases where the raw water contains appreciablequantities of suspended solids and organic matter.The pretreatment normally consists of acoagulation vessel followed by a sand and carbonfilter or, in some cases, a carbon filter on its ownsuffices. Automatic and manual equipment isavailable.

Typical applications:• Electronics industry - Certain specialised

industrial processes in the electronics industryand related fields require water with minimumspecific resistance of 18megohm/cm.Thisextremely high level of water quality is oftenreferred to as ‘electronic water’ or ‘ultra purewater’ and represents a total dissolved solidscontent in the range of 0.01 to 0.05 parts permillion.

• Pharmaceutical &. Cosmetic Production• Chemical Manufacture• Mirror Silvering - final rinse water• Distilleries - deproofing of spirits• High Pressure Boiler Feed Water

AWE design and supply complete treatmentsystems to consistently deliver this very high levelof water quality to work stations.

Demineralisers


Reverse Osmosis is now an acceptedand field tested process for theremoval of both ionisable and non-ionisable impurities from waterand other liquids, utilising hollowfibre or spiral wound modules. Unitscan be custom designed to suit allraw water conditions and capacities.

As Reverse Osmosis is a departure fromconventional water treatment processes,it has many unique advantages:• Capable of reducing ionisable

solids content in the raw water to below 5%

• Capable of eliminating particulatematter larger than the 0.45 micronsize

• Removes 99% of organic matter,bacteria and spores

• Does not employ mineral acids andalkalis, thus alleviating effluentdisposal problems

• Low operating and maintenancecosts

• Operates on water with a solidscontent beyond the economic levelof ion exchange

The complete plant generally includes thefollowing components;• Pre-treatment to reduce the

fouling tendencies of raw water• Adjustment of the Langelier Index

either by base exchange softeningor acidification

• Reverse Osmosis Unit, designed tosuit raw water conditions, capacityand quality specified

• Storage of treated water to meetflow demand to service

• Post treatment deionisers, ifnecessary, to polish treated water

Reverse Osmosis


With the increasing levels ofautomation required by industry,AWE have continuously upgradedthe type of control equipment whichis used on automatic systems.Microprocessor controlledequipment is now available for thewhole range of equipment, from thedomestic softener to the largedemineralisation plant. On the largecustom designed plants, AWE workclosely with the client, utilising theclient’s choice of microprocessor.

This enables clients to standardise onmicroprocessors throughout theirfactory and ensures ease ofmaintenance and training. AWE havedesigned and built control panelsusing all of the leading brands ofPLC. All control panels are built toIP55 standards using the highestquality components. Each panel isindividually designed and tested sothat client selected components,features and alarms can be readilyincorporated.

Control Systems


Chemical dosing is used in conjunction withseveral types of equipment. It is used withcoagulation vessels to create a ‘floc’ by dosingcaustic soda. Chemical dosing can also beused separately e.g. hypochlorite dosing tosterilise water supplies. AWE have a range ofchemical dosing sets using variable strokediaphragm dosing pumps of PVC or stainlesssteel construction.These are mounted ontop of a polyethylene tank and are completewith all necessary injection fittings andchemical hose.The dosing sets are availablein single or 3 phase and can be supplied witha number of options e.g. manual or electricmixer, manual or automatic pump flushingand low level chemical alarm.

Chemical Dosing

Air ProductsAlcoa (UK) Ltd.Allied BreweriesAlpha SteelAnglian WaterArjo WigginsAtomic Weapons EstablishmentAveciaBass BreweryBPB DavidsonBritish AirwaysBritish PetroleumBritish Steel CorporationBritvic Soft DrinksBudweiser breweryCoca - ColaCognis Performance ChemicalsColumbian ChemicalCoors BrewersCostainDalkia LimitedDevonport Management Ltd.Dow CorningEnronFord Motor CompanyFife PowerGE IndustrialGeorgia-PacificGuinness BreweryH.P. BulmerHoover LimitedJaguarKodakKings Lynn Power StationL.G. Philips DisplaysMatthew ClarkNippon Electric GlassPenn PharmaceuticalPepsiPilkington GlassProctor & GamblePowergenRechem InternationalRockwool Ltd.Rolls Royce Power EngineeringRoyal MintSchweppes BeveragesShell PetroleumSonySt Regis PaperSutton Bridge Power StationTarmac TopblockTetra PakThames WaterUnited DistillersVauxhall MotorsWelsh Water

Some of Our Clients


AWE (Anderson Water Equipment) Limited,Cardiff Bay Business Centre,Lewis Road,Ocean Park,Cardiff,UKCF24 5EL

TELEPHONE: +44 (0)29 20492848

FAX: +44 (0)29 20491369

WEB: www.aweltd.co.uk

SALES ENQUIRIES: [email protected]

GENERAL ENQUIRIES: [email protected]

AWE Head offices and manufacturing facilities are closeto excellent national and international transportationfacilities including air, sea, motorway and rail links.

uk water treatment engineers specialising in design ... · uk water treatment engineers...

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