Mechanical Vacuum Systems for Steel Degassing
Which vacuum technology do you choose when you’re building a new steel degasser or upgrading an existing system? Dry mechanical pumps or steam ejectors?
It's a key decision.
Mechanical dry pumps are supplanting traditional steam ejectors as the vacuum technology of choice for secondary metallurgy. Increasingly dry vacuum is the technology of choice for new installations, and the trend is accelerating. It is not hard to see why.
Lower running costs and improved productivity are just two of the reasons. Dry pumps have been proved to reduce energy costs by as much as 97% compared to steam ejectors.
High reliability and dependable performance are also key factors, given the exceptional demands that secondary metallurgy processes can make on vacuum equipment.
Higher pumping speeds, lower ultimate vacuum, minimal maintenance and lower environmental impact all lend further weight to the case for mechanical dry pumps.
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Edwards leads the way
Edwards leads the way in vacuum for secondary metallurgy by a considerable margin. Our leading market position is built on our understanding of customers’ processes and our expertise in providing vacuum solutions for VD, VOD and RH processes.
Edwards has by far the largest installed base of dry pumps in the global steel industry, including the world’s largest mechanical vacuum pumping system, in China. Used for degassing 230-tonne batches of liquid steel, the system has a pumping capacity of 1,000,000 m3/h at 0.67 mbar.
Yet our systems require the fewest number of pumps per tonne. Moreover, Edwards pumps can be easily integrated into existing systems, with as much or as little technical support as you need.
Edwards can take care of the commissioning and start-up phase onsite. We can assist with integration of controls into the customer’s device management system, fine-tuned to the particular process. And we offer a comprehensive range of options for after-sales service, maintenance and repair.
We don’t just supply vacuum pumps.
We provide solutions, and the system that’s right for you.
VD and VOD Processes
Processes in the growing secondary metallurgy sector depend on several vacuum-based treatments: Vacuum Degassing (VD) for alloy steels; Vacuum Oxygen Decarburising (VOD) for stainless steels; and combinations of both treatments, for example Vacuum Degassing -Oxygen Blowing (VDOB) and Vacuum Carbon Decarburising (VCD), for low and ultra-low carbon steels.
These processes operate at varying vacuum levels, with different process gas loads, and in differing types of vacuum vessels, including tank, lid, ladle to ladle, stream and RH designs.
Edwards vacuum systems have been successfully applied to all these secondary metallurgy processes at customers’ production facilities around the world. Modular system design enables degassing and decarburising melt sizes up to 200 tonnes in electric steelmaking facilities (mini-mills).
Whether you are planning a new installation at a greenfield site or upgrading/replacing an existing installation, Edwards is your vacuum partner of choice.
RH Processes
In large integrated steelmaking facilities, typically equipped with basic oxygen converters, secondary metallurgical processing is carried out mainly in Ruhrstahl Heraeus (RH) systems.
These facilities process steels in ladle sizes of over 400 tonnes and require much larger pumping capacities – up to 1,000,000 m3/hr or more. Until a few years ago, RH plants were considered too large for dry mechanical pumping systems. But technological advances and successful installations mean that the huge potential for dry pump technology in this process is now being recognised.
Edwards has developed a ‘super’ degasser module to address the high volume flow rates needed to successfully degas and decarburise steel products, using multiple high volumetric flow boosters in parallel to handle the gas loads produced, while optimising the total number of system elements required.
Whether you are planning a new installation at a greenfield site or upgrading/replacing an existing installation, Edwards is your vacuum partner of choice.
Operating costs comparison
| Operating Costs |
Steam Ejectors |
Dry running pumps
including filter
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€/tonne
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€/tonne
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Energy and fluids
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1,6041667
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0,0282000
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Maintenance
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0,5694556
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0,0042014
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Spares
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0,0100000
|
0,0300000
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TOTAL COST
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2,1836222
|
0,0624014
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Saving
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0%
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97%
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On a typical VD plant processing 300,000 tonnes of steel per year, the operating costs of a modular dry pump system can be less than 10% of the equivalent steam ejector system.
You can’t beat experience
Turnkey Systems from Edwards
Steel production innovation is a key driver for end users to help them secure a global competitive advantage. The secondary metallurgy process has proven benefits by converting steam ejector installations to dry vacuum technology. Part of the new process design involves vacuum dust filtration and complex control systems which complement the dry vacuum pumps and hence enable optimisation of the secondary steel production process.
Edwards Turnkey Systems are correctly positioned to not only provide the dry vacuum pumps but also provide the dust filter , systems control architecture , installation piping and end-to-end project management to customer specifications.
Edwards Turnkey Systems work closely with end user process and facility teams to ensure the plant-wide vacuum design delivers best-in-class cost of ownership whilst meeting project deadlines through secure product supply chains.
Aftersales service
Dry mechanical pumps require minimal maintenance. But all vacuum equipment needs servicing at some point. No matter how simple or complex your requirement, Edwards has the service solution that’s right for you.
Our expertise is in vacuum technology, we have been in the business since 1919 and our knowledge runs deep. We design, develop and manufacture vacuum equipment to the very highest standards. But it’s not just the technology. With a global installed base of 750,000 pumps, we understand how vacuum pumps and systems perform in real life. We know
how to get the best from our products, whatever the application. We know how to look after them. That’s why a large section of our expert workforce is dedicated to service and support.
Our service solutions come under three main headlines; on-site service, repairs and exchange, and quality spares. All built on our world-class technical know-how and backed by our sophisticated logistics and supply chain infrastructure.
Whether it’s quick telephone support, routine maintenance or establishing a complete embedded engineering team on site, Edwards is your vacuum partner of choice.
Looking for more information or support? Contact us today
Contact one of our application experts regarding your steel application:
Contact us form: Contact Us
Email us at: vacuum@edwardsvacuum.com
Turnkey systems: turnkey@edwardsvauum.com
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