The AutoFilt® RF3automaticback-flushing filter forprocess technology

The AutoFilt® RF3automaticback-flushing filterfor process technology

Designed for continuous andmaintenance-free filtrationin all sectors of industry.

The AutoFilt® RF3 automaticback-flushing filter is a self-cleaningsystem for extracting particles fromlow-viscosity fluids.Its rugged construction andautomatic back-flushing capabilitymake a major contribution tooperational reliability and reduceoperating and maintenance costs.

The slotted-tube filter elementswith filtration rates of 50 to 3,000 µmensure highly effective separation ofcontaminating particles from theprocess medium.

Automatic cleaning startsas soon as the elementsbecome contaminated.The filtrate flow is not interruptedduring the back-flushing procedure.

A range of filters of different sizesallows flow rates ofup to 10,000 m³ per hour.

Numerous combinations ofmaterials and equipmentas well as individually adjustablecontrol parameters allowoptimum adaptation of thefilter to any application.

Cost-effectiveness of theAutoFilt® RF3

Particle contamination in operatingfluids accelerates the rate of wearof system components, pipelinesand valves and often leads to theirpremature failure.In many cases, the use ofautomatic back-flushing filtersleads to a significant increasein service life andmaintenance intervals.

Costs for new purchases,maintenance and waste disposalcan thus be minimized.

AutoFilt® Type RF3- some examples of applications

Power stationsTreatment of industrial water forcooling generators and filtration ofsealing water to increase the servicelife of the turbine shaftsliding-ring sealsin hydroelectricpower stations.

Districtheat supplyProtecting heatexchangersfrom cloggingand wear.

ChemicalindustryImprovingproduct qualityby filteringprocessmedia.

Steel industryProtection of nozzles and pumpsduring high-pressure descaling,water treatment for coolingblast furnaces and rolling mills.

Sewage treatment plantsDuring production of industrial water,filtration of a take-off of the clear runcan be used to save valuable drinkingor well water.

Environmental technologyBack-flushing filtersare used as pre-filters beforewaste-water treatment plants(UV treatment, reverse osmosis,membrane filtration...).

MiningBy filtering underground,spray water of an even qualityis assured.This results in more reliable operationof pumps and disc-cutting machines.

Paper industryFor example: the protection of spray nozzles forthe screens ofpaper-making machines.This results in fewer failurescaused by clogging and wear.

Automotive industryMechanical engineeringMachine toolsCooling lubricant emulsionscan be kept much longer in circulation.This eases the pressureon the environment and reduceswaste-disposal andre-purchasing costs.Filtering of cooling and service waterprotects cooling channels andpipelines from clogging.

Special features of the HYDACAutoFilt® RF3

Isokinetic filtering and back-flushingThe special shape and configurationof the filter elements- conical or conical/cylindrical -allows even flow, resulting inlow pressure drop andcomplete cleaning of the elements.The advantage: fewer back-flushing cyclesand lower loss of back-flushing fluid.

Pulse-aided back-flushingIn control modes EPT and PTthe flushing arm remains under eachfilter element for only a few seconds.Rapid opening of the pneumaticback-flushing valve generates a pressuresurge in the openings of the filter elementsthat provides an additional cleaning effectto the back-flushing process.

Low back-flushing quantitiesdue to cyclic controlThe back-flushing valveopens and closes during back-flushingof each filter element.

Filtration

Back-flushingTriggeringautomatic back-flushingBack-flushing is triggeredautomatically:– when the triggering differential

pressure is exceeded,– by means of an adjustable timer,– when the TEST key is pressed.As soon as back-flushing has beentriggered, the filter starts to regeneratethe filter elements.

Back-flushing of thefilter elements - back-flushing cycle– The geared motor turns

the flushing arm under the filter elementsto be cleaned.

– The back-flushing valve is opened.– The pressure drop between

filtrate side and back-flushing lineflushes a small part of the filtratebackwards into the filter elementsto be cleaned.The contamination particles collectedon the inside of the filter elements areloosened and flushed into the back-flushing line via the flushing arm.

– As soon as the “back-flushing timeper element“ has elapsed,the back-flushing valve is closed.

All the filter elements are thus flushedin succession.A back-flushing cycle is terminated whenall the filter elements have been cleaned.

Back-flushingFiltration

Operation of theAutoFilt® RF3

FiltrationThe fluid to be filtered flows through theslotted-tube filter elements of the back-flushing filter, passing from the inside tothe outside. Contamination particles thencollect on the smooth inside of the filterelements. As the level of contaminationincreases, the differential pressurebetween the contaminated and cleansides of the filter increases. When thedifferential pressure reaches its pre-setvalue, back-flushing starts automatically.

The filters are designed specially to ensure good flow conditions and enablecompact dimensions with high filtration performance and low pressure drop.

Filtration

Example: EFQ100 < 3 for elements with filtration rating of 100 µm

AF

AE

AFEFQX =

AE

X = Filtration rating in µm

Element opening quotient EFQXThe element opening quotient (EFQX) determines even flow without reverse flowthrough the filter element during filtering and back-flushing.The EFQX value is the ratio of the open filtration surface of an elementto the cross section of the opening of the element inlet.

Freely selectable control parametersThe triggering differential pressureand back-flushing time per elementcan be adapted to best suit theprocess conditions.Timer relays can be usedto trigger additional cleaning intervalsindependently of the differentialpressure. The control procedure isdisplayed via LEDs. A secondmicroswitch on the pressure gauge canbe used for external filter monitoring.

A static seal between thecontaminated and clean sides of thefilter makes it impossible for particlesto penetrate the filtrate.

Ready-to-operate unitThe filter control unit and differentialpressure measuring line are alreadyconnected. Once the filter has beenfitted to the pipework,only the auxiliary power supplyneeds to be connected.

Variable filter isometryThe inlet and outlet flanges as well as the back-flushing linecan be configured in different positions.This means that the filter can be easily integrated into any plant layout.

Back-flushing

Summary oftechnical data:

Maximum operating pressure:10 or 6 bar*

Operating temperature:90 °C*

Filtration rate:50 to 3000 µm

Power supply:Electropneumatic, electric orpneumatic

Material of filter housing:Carbon steel or stainless steel

Material of filter elements:Stainless steel

Material of internal parts:Stainless steel

Corrosion protection for filterhousing made of carbon steel:Polyurethane or rubber coating

* Other models available on request.

Note:The information in this brochurerelates to the operating conditionsand applications described.For applications or operatingconditions not described, pleasecontact the relevant technicaldepartment.Subject to technical modifications.

The advantages ... and the benefits to you:of the AutoFilt® RF3...

Extensive standard features Excellent price/performance ratiofor individual applications

Fully-automatic operation Reliable and safeNo intervention by staff requiredLow operating costs

Continuous filtrate flow No interruption of operationeven during back-flushing

Flow rate up to 10,000 m3/h High process performance

Service-friendly Low maintenance costs

Isokinetic filtration and Maximum utilisation of filter surfaceback-flushing Full filtration performance

after back-flushing

Conical filter elements Unbeatable ∆p curveOptimum EFQX

Slotted-tube filter elements Long service lifeOptimum filtration andback-flushing properties

Pulse-aided back-flushing Additional dynamic elementcleaning with low loss of cleaning fluid

Individually adjustable Customer-specific adaptation to thecontrol parameters particular application

Flow-optimised filter High throughput withcompact dimensions

Static sealing between Guaranteed high filtrate qualitycontaminated and clean sides Low maintenance

Variable housing isometry Reduced costs due to space-savingand simple installation

Numerous equipment options Customer-specific adaptation to theparticular application

Ready-to-operate unit Simple installation andcommissioningGuaranteed reliabilitydue to HYDAC system test

ISO 9001 certification Consistently high quality

Automotive industry

Paper industry

Mining

Power stations Environmental technology

Chemical industry

Sewage treatment plants

Steel industry

District heat supply