Steel Degassing Brochure - Edwards

a clear edgeMechanical vacuum systemsfor steel degassingVacuum science... product solution.

a clear edgeenergy efficiency through vacuum

Mechanical vacuum systems for steel degassingEdwards leads the way in vacuum for secondarymetallurgy by a considerable margin. Our leading marketposition is built on our understanding of customersprocesses and our expertise in providing vacuum solutionsfor VD, VOD and RH processes.Edwards has by far the largest installedbase of dry pumps in the global steelindustry, including the world’s largestmechanical vacuum pumping system,in China. Used for degassing 230-tonnebatches of liquid steel, the system hasa pumping capacity of 1,000,000 m 3 /hrat 0.67 mbar.Yet our systems require the fewestnumber of pumps per tonne.Moreover, Edwards pumps can beeasily integrated into existing systems,with as much or as little technicalsupport as you need.Edwards can take care of thecommissioning and start-up phaseonsite. We can assist with integrationof controls into the customer’s devicemanagement system, fine-tuned tothe particular process. And we offera comprehensive range of options foraftersales service, maintenance andrepair.We don’t just supply vacuum pumps.We provide solutions, and the systemthat’s right for you.

Edwards leads the wayWhich vacuum technology do you choose when you’rebuilding a new steel degasser or upgrading an existingsystem?Dry mechanical pumps or steamejectors? It’s a key decision.For VD, VOD and RH processes, thesmart money is on dry technology.Increasingly mechanical dry pumps arereplacing traditional steam ejectorsas the vacuum technology of choicefor new installations, and the trend isaccelerating. It is not hard to see why.Lower running costs and improvedproductivity are just two of thereasons. Dry pumps have been provedto reduce energy costs by as much as97% compared to steam ejectors.High reliability and dependableperformance are also key factors,given the exceptional demands thatsecondary metallurgy processes canmake on vacuum equipment.Higher pumping speeds, lower ultimatevacuum, minimal maintenance andlower environmental impact alllend further weight to the case formechanical dry pumps.Dry orsteam?The choiceis yours

VD and VOD processesProcesses in the growing secondarymetallurgy sector depend on severalvacuum-based treatments: VacuumDegassing (VD) for alloy steels; VacuumOxygen Decarburising (VOD) forstainless steels; and combinations ofboth treatments, for example VacuumDegassing Oxygen Blowing (VDOB) andVacuum Carbon Decarburising (VCD),for low and ultra-low carbon steels.These processes operate at varyingvacuum levels, with different processgas loads, and in differing types ofvacuum vessels, including tank, lid,ladle to ladle, stream and RH designs.Edwards vacuum systems have beensuccessfully applied to all thesesecondary metallurgy processes atcustomers production facilities aroundthe world. Modular system designenables degassing and decarburisingmelt sizes up to 200 tonnes in electricsteelmaking facilities (mini-mills).RH processesIn large integrated steelmakingfacilities, typically equipped withbasic oxygen converters, secondarymetallurgical processing is carriedout mainly in Ruhrstahl Heraeus (RH)systems.These facilities process steels in ladlesizes of over 400 tonnes and requiremuch larger pumping capacities – up to1,000,000 m 3 /hr or more. Until a fewyears ago, RH plants were consideredtoo large for dry mechanical pumpingsystems. But technological advancesand successful installations meanthat the huge potential for dry pumptechnology in this process is now beingrecognised.Edwards has developed a ‘super’degasser module to address thehigh volume flow rates needed tosuccessfully degas and decarburisesteel products, using multiple highvolumetric flow boosters in parallel tohandle the gas loads produced, whileoptimising the total number of systemelements required.Whether you are planning a newinstallation at a greenfield site orupgrading/replacing an existinginstallation, Edwards is your vacuumpartner of choice.

Technical specification56601500 355026882240119011907624Note: this is an example of a typical steel degassing module system for VDapplications. Edwards systems can be adapted for individual customerrequirements