APPLICATIONS • PRODUCTS • ENGINEERING EXCELLENCE• CUSTOM DESIGN = ALL COME AS STANDARDMOTION CONTROLSOLUTIONSPRE-LOADEDRACK ANDPINION DRIVESDIGITALTENSIONCONTROLSYSTEMSHIGHPERFORMANCESERVOPLANETARYGEARHEADHIGHPRECISIONLOWBACKLASHBEVELGEARBOXESAndantex Ltd,Rowley Drive, Coventry CV3 4LSTel. 024 7630 7722Fax. 024 7630 4499sales@andantex.co.ukwww.andantex.co.ukELECTRICAL EQUIPMENTEnclosures, Cabinets & FansJust going through a phaseIntertec is claiming a world first with aninnovative passively cooled enclosure thatcould slash the costs of instrumentation andelectronics for remote environmentsIntertec has launched a passivelycooled enclosure that exploits anovel phase-change material tomaintain the temperature ofelectronics equipment at 10 degreeslower than peak ambient temperatures.Requiring no power supply to operate,Intertec has produced a standard coolingenclosure with enough internal space tomeet common application requirements,such as the pressure transmitters andprocess analysers used on oil and gaspipelines running through desertenvironments. Intertec believes this tobe the first application of phase changematerials to process instrumentation.“Protecting sensitive electronicsequipment against very hightemperatures has traditionally been anAphase change material (PCM) is asubstance with a high heat offusion which, melting and solidifyingat a certain temperature, is capable ofstoring and releasing large amounts ofenergy. PCMs latent heat storage canbe achieved through solid-solid, solidliquid,solid-gas and liquid-gas phasechange. However, the only phasechange used for PCMs in practicalapplications is the solid-liquidchange.Liquid-gas phase changes are notpractical for use as thermal storagedue to the large volumes or highpressures required to store thematerials when in their gas phase.Liquid-gas transitions do have ahigher heat of transformation thansolid-liquid transitions. Solid-solidphase changes are typically very slowand have a rather low heat oftransformation.Initially, the solid-liquid PCMsbehave like sensible heat storage(SHS) materials; their temperaturerises as they absorb heat. Unlikeconventional SHS, however, whenPCMs reach the temperature at whichthey change phase (their meltingtemperature) they absorb largeamounts of heat at an almostconstant temperature. The PCMcontinues to absorb heat without aexpensive exercise, especially if theapplication also demands explosionproof protection, or involves a locationthat is not served by an electricityinfrastructure,” says Martin Hess ofIntertec. “This new type of passiveenclosure gives remote equipmentdevelopers a valuable new option,providing a very simple and costeffective means of protecting smallerscaleelectronics equipment inenvironments with temperature swings,such as deserts.”Phase change materials (PCMs) canprovide a cooling mechanism byabsorbing and storing the large quantityof energy needed to change thematerial’s state from solid to liquid asthe melting point is passed – during thePhase change materials – background readingsignificant rise in temperature until allthe material is transformed to theliquid phase. When the ambienttemperature around a liquid materialfalls, the PCM solidifies, releasing itsstored latent heat.The most commonly used PCMsare salt hydrates, fatty acids andesters, and various paraffins (such asoctadecane). Recently ionic liquidshave also been investigated as novelPCMs. As most of the organicsolutions are water free, they can beexposed to air, but all salt based PCMsolutions must be encapsulated toprevent water evaporation or uptake.Both types offer certain advantagesand disadvantages and if they arecorrectly applied some of thedisadvantages becomes an advantagefor certain applications.As phase change materialsperform best in small containers, theyare usually divided in cells. The cellsare shallow to reduce static head. Thepackaging material should conductheat well, and it should be durableenough to withstand frequent changesin the storage material’s volume asphase changes occur. It should alsorestrict the passage of water throughthe walls, so the materials will not dryout (or water-out, if the material ishygroscopic).normal daytime temperature rise. Thisenergy is then released as the PCM resolidifiesduring cooler periods, making itideal for use in desert locations withtheir cold night time temperatures. Forthis application, Intertec has chosen aPCM with a phase change temperatureof 34°C.Passive coolingThe first enclosure produced by Intertec,the PCM Passive Cooling System,provides approximately 25 litres ofusable space for mounting electronicsequipment, and will dissipate up to 10Wof heat. Moreover, there is no need toadd fans or vents, so an enclosure’senvironmental ingress protection (IPrating) against dust and water remainsunchanged.The phase change material is locatedat the back of the enclosure, behind amounting panel. The electronics deviceor equipment to be protected is attachedto this panel with as large a contact areaas possible to aid heat conduction.Intertec offers ready-to-use pipe clamplikeaccessories for mounting processtransmitters, and will also fabricatesimple mechanical panel-mountingaccessories for other equipment shapessuch as small electronics modules.The enclosure itself is fabricatedusing special insulated constructionprinciples developed and field proven byIntertec over many years. The basicmaterial used is long fibre reinforcedglass-reinforced polyester (GRP)sheeting, which provides great structuralstrength, combined with high resistanceto weather and the corrosive effects ofaggressive chemicals.Special mounting and constructionprinciples for the internal componentsthen ensure that the very high degree ofthermal insulation provided by this shellis not compromised by providing a pathfor heat conduction. The enclosure isalso compatible with Intertec’s standardrange of accessories including sunshades to protect the top and/or sides, toprovide further optimisation of theenclosure for use in hot environments.Intertec’s new enclosure can delivermajor reductions in system <strong>building</strong>22More details: Write in 220INDUSTRIAL TECHNOLOGY • November 2008
Compatible withTS 8 accessoriescosts. Alternative cooling mechanismssuch as air conditioning and vortexcoolers usually involve thousands ofpounds of extra hardware costs, aswell as the need for a local powersupply to power the pumps orcompressors required. These costs canescalate again if explosion proofprotection is required, as is typicallythe case for pipeline equipment.Low efficiencyPeltier coolers are an alternative forsmaller-scale electronics, but theirrelatively low efficiency means that asubstantial local power supply can berequired. Such cooling methodstypically necessitate connectionsbetween the internal and externalenvironments as well, such as vents orfans, complicating the provision ofprotection against dust and rain.Intertec’s unpowered PCM PassiveCooling System costs typically lessthan $1500 in and has zero runningcosts and no regular maintenancerequirements. A range of otherenclosure and PCM material blocksizes are optionally available, to suitlarger or smaller electronics equipmentand varying heat dissipationrequirements.Intertec’s portfolio of enclosure,cabinet and shelter solutions forprotecting field instrumentationincludes GRP enclosures andprotective shades in a range of shapesand sizes, GRP cabinets and sheltersfor use in almost any climate orweather conditions, accessoriesincluding heating systems, and customdesign and turnkey system assemblyservices. Intertec supplies most of theworld’s major oil, gas, petrochemicaland chemical organisations, from itsnetwork of manufacturing and salesoffices worldwide, and via a largenetwork of agents and distributors. Todate, Intertec has supplied well overhalf a million protection systemsworldwide.MORE INFORMATION:Enter K225 or visit ‘latest issue stories’ atwww.industrialtechnology.co.uk for furtherdetails from IntertecRittal CM -Compact System EnclosureThe idea: Compact enclosures that offer the installationflexibility of large cabinets• The answer: Rittal Compact System Enclosure CM• Diversity: Complete interior installation with TS 8 systemaccessories• Fast: Rapid attachment, the mounting plate is insertedat the bottom and simply secured at the top with clips• Flexibility: All cable entry option covered, more space,more stability and more opportunities for cable entry.• Automatic: Automatic potential equalisation through therail systemFor further information:Rittal Limited, Braithwell Way, Hellaby <strong>Industrial</strong> Estate,Rotherham, S Yorks S66 8QYTel.: 01709 704000 – Email: information@rittal.co.uk.www.rittal.co.ukNovember 2008 • INDUSTRIAL TECHNOLOGYMore details: Write in 230 on the free information card23
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