Descaling systems - Woma

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Descaling systems - Woma

ContentsIntroductionSCHÄFER & URBACH competence profile.....................................................................................................................................3Descaling systems and components..............................................................................................................................................4Functional description of a descaling unit.....................................................................................................................................4General description of plunger pumps..........................................................................................................................................5Comparison of plunger and rotary pumps....................................................................................................................................6Descaling unit for different-sized forging ingots in a wheel rolling millNizhniy Tagil, Russia........................................................................................................................................................................7Primary descaling box for end surface and lateral areasINA SCHAEFFLER, Romania S.R.L.................................................................................................................................................10Descaling solution for a continuous casting plant with four individual strandsHKM, Germany.............................................................................................................................................................................11Primary scale removal plant for slabs and ingotsSEVERSTAL, Russia........................................................................................................................................................................13Descaling of steel rodsYARTSEVO, Russia.........................................................................................................................................................................15Descaling unit for a hot rolling millHyundai Steel, South Korea.........................................................................................................................................................16Descaling unit for a wide hot strip millSalzgitter, Germany......................................................................................................................................................................17Reference list of supplied descaling units..............................................................................................................................19SCHÄFER & URBACH GmbH & Co. KG · Kaiserswerther Straße 74 · 40878 Ratingen - GermanyPhone: (+49) 21 02 / 45 07 - 0 · Fax: (+49) 21 02 / 45 07 - 45 · Internet: www.schaefer-urbach.com


Tradition as basis – high-pressure as motivationAs specialists for sophisticated solutions SCHÄFER & URBACH have become renowned in the following areas.Water hydraulicsDescaling systemsDrive systems for pressesHigh-pressure technologyTank cleaning systemsCleaning of heat exchangersHigh-pressure cleaning equipmentIndustrial pumpsMud pumpsProcess pumpsHigh-pressure pumpsWelding technologyCooling systemsHeat exchangersIndustrial serviceFor more than 80 years SCHÄFER & URBACH have developed and supplied equipment and components for systems and highpressureplants to customers throughout the world. All of the supplied equipment is manufactured at the SCHÄFER & URBACHworkshop. The company assumes responsibility, as it supplies complete high-pressure and systems solutions made up ofcomponents which all fit together seamlessly – forming a perfect match and being ... all from one source.Water-hydraulic systems solutionsServices provided by SCHÄFER & URBACH comprise planning, design, assembly and commissioning of water-hydraulic plantand equipment as well as after sales service and spare part delivery for plants in operation. SCHÄFER & URBACH offers allservices on a turn-key basis and from a single source. SCHÄFER & URBACH sees itself as a supplier of high-pressure systemswithout interfaces.SCHÄFER & URBACH designs and realizes water-hydraulic systems solutions for:Descaling systems – More surface quality in rolling and forging plantsPress drives – Customized solutions for the replacement and modernization of forging press drivesSCHÄFER & URBACH GmbH & Co. KG · Kaiserswerther Straße 74 · 40878 Ratingen - GermanyPhone: (+49) 21 02 / 45 07 - 0 · Fax: (+49) 21 02 / 45 07 - 45 · Internet: www.schaefer-urbach.com


Descaling systems– We do not remain at the surface!SCHÄFER & URBACH designs, supplies and assembles bothindividual components for descaling systems as well ascomplete descaling units for the removal of primary andsecondary scale. The equipment is designed accordingto the latest state of the art in descaling technologyusing Lechler descaling software. Numerous rolling millsthroughout the world have benefited from the reliabilityof the systems in terms of surface quality improvementsand marked savings in energy costs and / or spray water.Systeme / PlantsSCHÄFER & URBACH provides technical advice, anddesigns and supplies descaling systems for:Continuous casting lines / slabsPlatesForged and shaped partsHot stripBars / rodsSectionsComponentsSCHÄFER & URBACH naturally also handles modernizationprojects for existing plants and / or delivers individualcomponents, such as:Descaling boxesDescaling valvesSpray headers and ringsDescaling pumpsResonatorsPre-filling at low pressureShut-off valvesCheck valvesAccumulator emergency stop valvesIntroduction(Functional description of a descaling unit)The below described descaling units serve to remove theprimary scale forming on metallic surfaces during furnacetreatment. The scale layer is removed by water beingsprayed onto the metal surface at high pressure while thematerial is passing through a dedicated descaling cabin.Primary scale is removed essentially by three physicalprocesses. The individual contribution of each of theseprocesses to the descaling result depends on the type ofscale forming in the furnace, which in turn is determinedby the type of material heated in the furnace.The following three physical mechanisms can bedistinguished:1. Generation of heat stress in the scale layer due tocooling2. Explosive energy as a result of the increasing volume ofwater when it evaporates3. Mechanical forces caused by the impact of the water jetMaterials tending to form a relatively thick andporous scale mainly benefit from the first two physicalmechanisms. By contrast, the third mechanism is moreeffective with materials forming a thin, coherent andadhesive layer of scale. The latter type of scale is calledsticky scale and it is much more difficult to remove thanscale of the first category. SCHÄFER & URBACH designsand supplies individual components for descaling systemsas well as complete descaling units for unalloyed, lowalloyand high-alloy steels, including assembly andcommissioning.SCHÄFER & URBACH GmbH & Co. KG · Kaiserswerther Straße 74 · 40878 Ratingen - GermanyPhone: (+49) 21 02 / 45 07 - 0 · Fax: (+49) 21 02 / 45 07 - 45 · Internet: www.schaefer-urbach.com


General description of plunger pumpsPlunger pump S&U HPP 180-3The use of plunger pumps is recommended whereverrelatively high pressures and relatively small pumping ratesare needed. The flow volume depends on the plungerdiameter, plunger stroke and the speed of the drive shaft.Combining several plunger units into one pump unitwith overlapping strokes reduces the surges which occurwhenever a stroke takes place. In each case the conditionsat the infeed side of the pump deserve special attention,as they are dependent on the routing of the pipes, theprimary pressure, the temperature of the fluid and otherfactors. The design and manufacture of SCHÄFER &URBACH products comply with the EU pressure equipmentdirective (RL97/23/EC).SCHÄFER & URBACH GmbH & Co. KG · Kaiserswerther Straße 74 · 40878 Ratingen - GermanyPhone: (+49) 21 02 / 45 07 - 0 · Fax: (+49) 21 02 / 45 07 - 45 · Internet: www.schaefer-urbach.com


Comparison of plunger and rotary pumps in descaling plantsPlunger pumpsPressurization through line resistance aftergeometric displacementPressures up to 5,000 bar, no limits for strengthreasonsNo special design even at ultra-high pressuresExtremely high overall efficiencies up to about95%Low speeds up to about 375 rpmGear reduction using single-stage standardcylindrical gears, low costsAt constant speed pumping rate is virtuallyindependent of operating pressure; flow rate isproportional to speedIn intermittent mode, simple switching frompressure mode to pressureless circulation bylifting the suction valve, at the same timereducing power input to about 3% of theengine ratingPlunger pumps are used in virtually allindustrial sectors, e.g. in descaling, rolling andmetallurgical technologyRotary pumpsDynamical pressure increase of the pumping medium (water)through speed increasePressures of up to 250 bar for rotary pumps in descaling units.Strength limitations imposed by impeller diameter and speedTo accommodate different pumping rates high-pressure rotarypumps must be designed as multi-stage pumps and equipped withcorresponding axial balancing equipmentExtremely high overall efficiencies up to about 75%Very high speeds up to about 5,000 rpmPossibility of gearing only by means of special turbo-gears; highcosts, few qualified manufacturersPumping rate at constant speed dependent on counter-pressure;operation constantly at Q-H curveDuring intermittent operation with the consumer locked about 50-70% of the drive power is converted into heat. In order to preventoverheating a bypass is arranged near the pressure joint, releasingsome 20% of the volume. This avoids evaporation of the rotarypump. Power input amounts to some 60% of the engine ratingThere are no HPP rotary pumps specifically designed for descaling;all HPP pumps are modified boiler feeding pumps. In rollingmill and steel works applications as well as in power plants withclean boiler feedwater, boiler feeding pumps usually operate atoptimal efficiencies. However, HPP rotary pumps used in descalingapplications constantly operate in throttle mode, with Qmaxamounting to about 1.3 x Qn and Qmin being determined bythe required bypass volume. This mode of operation means thatthe blades are subjected to high-speed water flows coming fromconstantly changing directions. Especially at the discharge side of theimpeller high stresses may occur.If the number of stages is high, the remaining radial forces underpartial load may cause localized collision in the narrow sealing gaps.SCHÄFER & URBACH GmbH & Co. KG · Kaiserswerther Straße 74 · 40878 Ratingen - GermanyPhone: (+49) 21 02 / 45 07 - 0 · Fax: (+49) 21 02 / 45 07 - 45 · Internet: www.schaefer-urbach.com


Descaling unit for different-sized forging ingots in a wheel rolling plantNizhniy Tagil, RussiaComplete descaling cabinDimensions and weightLength approx.Width approx.Width with doors open, approx.Height approx.Weight:4,700 mm3,600 mm5,000 mm3,950 mm9,750 kgSCHÄFER & URBACH GmbH & Co. KG · Kaiserswerther Straße 74 · 40878 Ratingen - GermanyPhone: (+49) 21 02 / 45 07 - 0 · Fax: (+49) 21 02 / 45 07 - 45 · Internet: www.schaefer-urbach.com


1 primary descaling box for end surface and lateral areasfor forged blocks with different dimensionsINA SCHAEFFLER, Romania S.R.LDescaling boxInside of boxValve engineering10SCHÄFER & URBACH GmbH & Co. KG · Kaiserswerther Straße 74 · 40878 Ratingen - GermanyPhone: (+49) 21 02 / 45 07 - 0 · Fax: (+49) 21 02 / 45 07 - 45 · Internet: www.schaefer-urbach.com


Descaling solution for a continuous casting plant with four individual strandsHKM, GermanyComplete descaling unit for a continuouscasting plant with four individual strandsMain sections of the descaling plantThe descaling plant consists of three main sections. Thefirst one comprises all components next to the castingstrands, the second one the components located in thearea of the high-pressure water pumps and the third onethe components making up the filter station on the lowpressureside.11SCHÄFER & URBACH GmbH & Co. KG · Kaiserswerther Straße 74 · 40878 Ratingen - GermanyPhone: (+49) 21 02 / 45 07 - 0 · Fax: (+49) 21 02 / 45 07 - 45 · Internet: www.schaefer-urbach.com


Components of the descaling systemHKM, GermanyComplete descaling unitSlabs after descalingPlunger pump stationThe descaling unit includes four plunger pumps, two eachbelonging to one slab line. Each pump has its own PLCcontrol for exchanging data with the higher-level controlsystem.The function of the plunger pumps is to pressurize thewater up to a level high enough press the total flow ratethrough the nozzles of the spray header. However, forthe actual descaling operation only one pump each isrequired. The second plunger pump serves as a stand-byunit. This provides the possibility of servicing or repairing apump during running operation.The pumps are driven by frequency-controlled electricengines which adjust the required spraying pressure to thedifferent materials to be descaled.Filter stationThe water drawn from the operator’s water supply systemis guided - by means of a manual shut-off valve - to one oftwo backflush filters arranged in parallel. The degree ofcontamination of the filters is monitored by differentialpressure switches. The two automatic reversible flowfilters feature an autonomous control.Reverse flushing is triggered when a differential pressureof 0.8 bar is reached. Upon attainment of this differentialpressure level, the information that reverse flushing hasbeen initiated is sent to the high-level control system.Additionally, data about the operating status of theautomatic backflush filters is transmitted to the high-levelcontrol.12SCHÄFER & URBACH GmbH & Co. KG · Kaiserswerther Straße 74 · 40878 Ratingen - GermanyPhone: (+49) 21 02 / 45 07 - 0 · Fax: (+49) 21 02 / 45 07 - 45 · Internet: www.schaefer-urbach.com


Components of the descaling systemSEVERSTAL, St. Petersburg – RussiaS&U PPW200Spray headerWater pump S&U PPW 200The industrial pump of the S&U PPW 200 type is acompact high-capacity pump for the medium pressurerange of up to 500 bar operating pressure.Drive power:up to 600 kWPiston force:up to 200,000 NEngine speed (rpm):995 - 1788 U/min.Crankshaft speed (rpm): 221 - 252Transmission ratio: 4.54 - 7.5Pressure:100 - 500 barPumping rate:300 - 2,500 Liter/min.Stroke:180 mmTriplex pump14SCHÄFER & URBACH GmbH & Co. KG · Kaiserswerther Straße 74 · 40878 Ratingen - GermanyPhone: (+49) 21 02 / 45 07 - 0 · Fax: (+49) 21 02 / 45 07 - 45 · Internet: www.schaefer-urbach.com


Descaling of steel rodsYARTSEVO, RussiaPlunger pump of the descalingplant at YartsevoThe descaling unit includes two plunger pumps. Thefunction of the plunger pumps is to pressurize the waterup to a level high enough press the total flow rate throughthe nozzles of the spray ring. However, for the descalingoperation only one pump is required.The second plunger pump serves as a stand-by unit.(See also at “Descaling plant at HKM, Germany“)Spray ringsmounted in a frame15SCHÄFER & URBACH GmbH & Co. KG · Kaiserswerther Straße 74 · 40878 Ratingen - GermanyPhone: (+49) 21 02 / 45 07 - 0 · Fax: (+49) 21 02 / 45 07 - 45 · Internet: www.schaefer-urbach.com


Descaling unit for a hot rolling millHyundai Steel, South KoreaPositions of the descaling unitswithin the roll millPrimary descalingSecondary descaling16SCHÄFER & URBACH GmbH & Co. KG · Kaiserswerther Straße 74 · 40878 Ratingen - GermanyPhone: (+49) 21 02 / 45 07 - 0 · Fax: (+49) 21 02 / 45 07 - 45 · Internet: www.schaefer-urbach.com


Descaling unit for a wide hot strip millSalzgitter – GermanyLayout of the pumping stationThe pumping station (see layout) with its 8 high-pressurepiston pumps forms the heart of the plant. Each pump hasa power rating of 470 kW. The total pumping capacity ofthe plant is 230 m 3 /h at an operating pressure of 450 bar.The unit includes one descaler each downstream of thefurnace and upstream of the finishing mill. As slabs ofdifferent thicknesses are descaled, the top spray headersmust be lifted and lowered by hydraulic cylinders in orderto maintain a constant distance of 100 mm between thenozzles and the slab surface. The equipment is laid out fora maximum stroke length of 110 mm (the thinnest slab isonly 150 mm thick, the thickest one 260 mm).The descaler upstream of the finishing train works thesame way. Likewise, the material to be descaled variesin thickness. Therefore the headers are also liftable bymeans of hydraulic cylinders and position transducers. Themaximum stroke length is only 15 mm (the thinnest stripgauge is 35 mm, the thickest one 50 mm).As a provider of systems solutions SCHÄFER &URBACHsupplied the detail engineering including electricalcontrols, the complete mechanical equipment and all ofthe electrical systems.17SCHÄFER & URBACH GmbH & Co. KG · Kaiserswerther Straße 74 · 40878 Ratingen - GermanyPhone: (+49) 21 02 / 45 07 - 0 · Fax: (+49) 21 02 / 45 07 - 45 · Internet: www.schaefer-urbach.com


Reference list of supplied descaling units1. GEBR. BÖHLER & CO., KAPFENBERG1 primary descaling unit for ingots and bars2. GEBR. BÖHLER & CO., DÜSSELDORF1 primary descaling unit for billets3. ÖSTERREICHISCH-ALPINE-MONTAGEGESELLSCHAFT, JUDENBURG1 primary descaling unit for billets, 3 secondary descaling units for rods4. GEBR. BENTELER, SCHLOSS-NEUHAUS, PADERBORN1 primary descaling unit for the jacket surface and both end faces of ingots for thefabrication of pipes on steel extruders5. TECHSTRANG, BULGARIA, VIA SCHLOEMANN AG, DÜSSELDORF1 primary descaling unit for the jacket surface and both end faces of ingots for thefabrication of steel sections on steel extruders6. CHISTAL I, PEKING, VIA SCHLOEMANN AG, DÜSSELDORF1 primary descaling unit for the jacket surface and both end faces of ingots as well asthe holes on ingots with holes for the fabrication of pipes on steel extruders7. CHISTAL II, PEKING, VIA SCHLOEMANN AG, DÜSSELDORF1 primary descaling unit for the jacket surface and both end faces of ingots for thefabrication of pipes on steel extruders8. INDURAD, RUMANIA, VIA SCHLOEMANN AG, DÜSSELDORF1 primary descaling unit for the jacket surface and both end faces of blooms for drop forging presses9. UNITED STATES STEEL, USA, VIA SCHLOEMANN AG, DÜSSELDORF1 primary descaling unit for the jacket surface and both end faces of blooms for drop forging presses10. TUBOS FORJADOS, SPAIN, VIA DEMAG AG, DUISBURG11 primary descaling unit for the jacket surface on ingots for pipe fabrication on pipe rolling mills1 secondary descaling unit for rough-pierced pipe blanks11. ROHRWALZWERK KOMOTAU, CZECHOSLOVAKIA, VIA DEMAG AG, DUISBURG1 primary descaling unit for the jacket surface and both end faces on ingots for pipe fabrication on pipe rolling mills3 secondary descaling units for rough-pierced pipe blanks and mandrel rods12. GEBR. BÖHLER & CO., KAPFENBERG3 primary descaling units for billets, 4 secondary descaling units for rods13. STAHLWERKE-BRÜNINGHAUS, WERDOHL10 primary descaling units for swaging hammers and forging machines19SCHÄFER & URBACH GmbH & Co. KG · Kaiserswerther Straße 74 · 40878 Ratingen - GermanyPhone: (+49) 21 02 / 45 07 - 0 · Fax: (+49) 21 02 / 45 07 - 45 · Internet: www.schaefer-urbach.com


Reference list of supplied descaling units14. VOEST-ALPINE, VIENNA1 primary descaling unit for billets15. SHARIAR PIPE MILLS, IRAN, VIA DEMAG AG, DUISBURG1 primary descaling unit for the jacket surface and both end faces on ingots for pipe fabrication on pipe rolling mills3 secondary descaling units for rough-pierced pipe blanks and mandrel rods16. BARZIEH, INDIA, VIA SCHLOEMANN-SIEMAG AG, DÜSSELDORF1 secondary descaling unit for square ingots17. STANKO-IMPORT, MOSKAU, VIA THYSSEN-RHEINSTAHL, ESSEN2 secondary descaling units for 44 different shaped parts18. MANNESMANNRÖHREN-WERKE AG, DÜSSELDORF1 primary descaling unit for the jacket surface and both end faces on round blooms19. DUNAFERR, LÖRINCI HENGERMÜ KFT, HUNGARY1 primary descaling unit for cogged ingots in sheet-rolling mills20. SMS DEMAG AG, DÜSSELDORF1 descaling unit for IPB-profiles with turnable nozzle holder21. SMS DEMAG AG, DÜSSELDORF1 descaling unit for various profiles22. SMS EUMUCO GMBH FOR MANSHAN, CHINA1 set of components for primary descaling system for blocks with 2 different dimensions23. SEVERSTAL S.A., CHEREPOVETS1 primary descaling unit for ingots and slabs24. SMS EUMUCO GMBH FOR NIZHNIY TAGIL, RUSSIA1 primary descaling unit for blocks with 2 different dimensions25. HKM HÜTTENWERKE KRUPP MANNESMANN GMBH, DUISBURG1 descaling unit for continous casting system consisting of 4 single lines26. YARTSEVO, RUSSIA1 descaling unit for square slabs27. HYUNDAI - STEEL, SOUTH KOREA1 descaling unit for micro- alloyed sheets in a hot rolling mill28. INA SCHAEFFLER, ROMANIA S.R.L1 primary descaling box for end surface and lateral areas for forged blocks with different dimensions20SCHÄFER & URBACH GmbH & Co. KG · Kaiserswerther Straße 74 · 40878 Ratingen - GermanyPhone: (+49) 21 02 / 45 07 - 0 · Fax: (+49) 21 02 / 45 07 - 45 · Internet: www.schaefer-urbach.com


Tradition as basis – high-pressure as motivationSCHÄFER & URBACHGmbH & Co. KGHeadquarters:Kaiserswerther Straße 7440878 Ratingen - GermanyPhone: (+49) 21 02 / 45 07 - 0Fax: (+49) 21 02 / 45 07 - 45Branch Office:Breitenseer Weg 2-697633 Hoechheim - GermanyPhone: (+49) 97 64 / 91 91 - 0Fax: (+49) 97 64 / 91 91 - 40E-Mail: info@schaefer-urbach.comInternet: www.schaefer-urbach.comDIN EN ISO 9001:2000EU Guidelines: 97/23/EG pressure equipmentEU Guidelines: 97/23/EG ATEXexplosion protection for cleaning lancesand high-pressure equipmentQualification according to DIN 18800 Part 7Certificate according toDIN EN 729-2 for welded structuresCertificate according toAD Guidelines HP 0 (TRB 200), TRD and TRR 100Specialist firm according to §19 WHGSCHÄFER & URBACH · Spritzkanone_1008 · Errors excepted. Technical changes possible.

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