Caldyn - Model CALWIR - Scrubber- Brochure

TECHNICAL INFORMATION QN 2003CALDYN Quenching Systems Apparatebau GmbH PrincipleQuenching systems employatomising devices for water dropletgeneration. The water droplets inthe spray evaporate using heat outof the flue gas. A reliable operationof the cooler requires the completeevaporation of the water droplets atlow temperature variations at thecooler outlet.Substantial for the reliable designof a quenching system are:? atomising system? gas flow conditions? control systemCALDYN has experience inplanning, engineering, installationand commissioning of quenchingsystems for more than 20 years.CALDYN has delivered more than100 quenching systems worldwidein:? chemical industry? power plants? copper industry? glass industry? waste incineration plants? steel industry? cement industry? zinc industryFig 1 Commissioning of a quenching system(5 lances / 5 m tower diameter/ 19 t/h water atomisation) Atomising systemThe nozzle with internal mixingchamber, developed by CALDYN(German patent 1976), allows thegeneration of a defined and narrowdroplet size distribution at lowenergy consumption.The angle of atomisation for singleCALDYN nozzles is equal to 15°.Therefore quenching systems canbe realized in very small channels.By using multiple orifice clusternozzles the angle of atomisation canbe varied for optimal adaptation tothe cross sectional area of thequenching tower (see technicalinformation CALDYN nozzles CSL).Due to the atomisation principleCALDYN nozzles work with lowvelocities and have a minimumclearance which is large enough toavoid plugging. Therefore alsoindustrial water can be used forcooling in the CALDYN quenchingsystems.The required cooling lengthdepends on the square of themaximum droplet diameter in thespray. Therefore small differencesin spray quality can result in erraticperformance of the quenchingsystem.Besides the development oftheoretical methods, measurementsare carried out at the CALDYN teststand regularly.The CALDYN computer programs forquenching design are based ontheoretical analysis, laboratory andfield experience.Fig 2: Distribution of droplet size andvelocity measured with PDPAFig. 3: PDPA lasertransmitterFig 4: Droplet velocity distributionFig.5: PDPA printout Gas flow conditionsThe flue gas flow must be uniformand parallel to the tower axis.Otherwise water droplets can touchthe tower walls due to cross flowsbefore they are completelyevaporated. This can lead to locallump formations depending on dustcharacteristics and gastemperature.If required CALDYN plans andmanufactures efficiently flowequalizers for generating uniformand parallel gas flow conditions(Fig. 6 and Fig. 7).Use of flow equalizers reducesmaintenance time for cleaning thetower walls especially in systemswith high dust concentrations.Depending on the operatingconditions and the design even nocleaning will be necessary. Control systemThe outlet temperature variationscan be reduced down to ±5°K byoptimal coordination of temperaturemeasurement devices, temperaturecontroller and water regulatingsystem.A finer spray quality is required forcomplete evaporation at part loadconditions with lower gas inlettemperatures.In the CALDYN quenching systemsspecial controllers in the pressureair line before the lances keep theair flow rate constant.Fig. 7 Flow equalizer MULTIWIRFig. 9 Circular pipelines withatomising lances and valvesFig. 8 Control box with luminouscircuit diagramFig. 10 Printout of inlet/outlet temperatures and water flow ratered=inlet temp. / green=outlet temp./ blue=water flow rate ® ¬5min¯-100 °CThis results in higher specific pressureair flow for the atomisation at part loadconditions. Therefore a reliableoperation of the quenching systemwithin the range of regulation andduring starting-up and shutdowncycles is ensured.While using more than one atomisinglance the controllers are balancing thewater flow at the lances automatically.Zones of different temperature in thegas stream due to different waterflows at the lances are avoided.Fig. 6 Quenching tower with flowequalizerflue gasflow equalizeratomising-lancesFig. 11 Scheme quenching systemflue gasinletflue gasoutletdust removalairwaterflow equalizeratomising lancewater tankpressure air regulationwater regulationtemperature-measurement 2xtemperature-measurementcompressorvessel CALDYN control stationsFig. 12 Pump station, regulating station water/pressure airand control box skid-mounted with internal wiringFig. 15 Pump station, regulating station water/pressure air(switchable from normal to max. load) and terminalbox skid-mounted with complete internal wiringFig. 16 Installation of PP water tank, pump station andregulating station water/pressure airFig. 17 Installation of stainless steel water tank, pumpstation and regulating station water/pressure airFig. 14 Regulating station water/pressure air and terminalbox, installed in a box with integrated electricalheatingFig. 13 Pump station, regulating station water/pressure airand terminal box skid-mounted with completeinternal wiring. Segments of circular pipelines.Fig. 19 Quenching tower steel industry (Luxembourg)Fig. 18 Installation of a quenching tower hot gas unitFig. 22 Fabrication of a quenching tower(high temperature design with refractory) CALDYN system installationsFig. 20 Pneumatic operated slide gate valve mounted atthe dust outlet cone of a quenching towerFig. 21 MULTIWIR packing as flow equalizer in a wasteincineration plant (ø3,8 m)Fig. 23 Lances and flexible suspended frame with chainsFig. 24 Quenching tower in the chemical industry(Germany)Fig. 25 Quenching tower in the steel industry (Switzerland) CALDYN system installationsFig. 26 Quenching tower in a wood incineration plant(Germany)Fig. 28 Quenching tower in the glass industry (France)Fig. 27 Quenching tower in the steel industry (Switzerland)Main advantages of the CALDYN system? Low pressure air consumption ? Small dimensions of the quenching tower? Long wearing and plugging-free nozzles ? Dry tower walls? Using of lances with several nozzles ? Using of industrial or waste water possible? Automatic balancing of the water flow at the lances ? Low temperature variations at the gas outlet? Using of steam instead of pressure air possible ? High range of regulationScope of supplyCALDYN scope of consultancy and supply ranges from basic and detail engineering up to delivery ofcomplete quenching plants.ReferencesCALDYN has delivered quenching systems to the following companies:Apparatebau GmbHGrashofstraße 12D-76275 EttlingenTel. ++49-7243/5403-0Fax ++49-7243/5403-99E-mail: info@CALDYN.de / Internet: http://www.CALDYN.deLÜHR FILTEROur complete reference list with technical data will be sent on request.