PULSE VALVES
Pulse valves
On the basis of these findings at the IEHK , a SIP test system for blast furnaces was constructed . Compared to the SIP system for cupola furnaces , significantly larger nominal diameters and pressures were now used , so the system had to be adapted and equipped with suitable components . One of the main focal points was the so-called pulse valves . These had to be capable of generating the strongest possible shock wave . Following a long series of investigations with different valve types , the sliding gate valve from Schubert & Salzer was selected . The principle of this valve was fascinatingly simple : two slotted discs that slide over each other and seal against each other . A sealing plate , fixed perpendicular to the direction of flow on which another movable disc with the same slot arrangement is moved , changes the flow cross-section . The applied pressure difference presses the movable disc against the fixed disc and thus contributes to leak-tightness . The short opening times achievable by this principle and the pressure resistance with large nominal diameters were ultimately decisive .
Phase 2 : From experiment to industrial use ( 2011 – 2020 )
The first tests with the SIP test system on the Schwelgern 1 blast furnace yielded such promising results that thyssenkrupp Steel Europe decided to further develop the process beyond the research project . With its hearth diameter of 13.6 m , a total
height of approx . 110 m and an internal volume of 4,416 m3 , the Schwelgern 1 blast furnace has a potential output of 10,000 t per day . The welded steel construction , which is lined inside with refractory material and has a closed cooling water circuit , is one of the most modern blast furnaces in the world . Rainer Klock was to manage the further development of SIP as plant engineer and was appointed by thyssenkrupp Steel Europe towards the summer of 2010 . Whilst an industrially operational prototype had to be created on the basis of the SIP test system , this prototype was further optimised . “ To further improve the effect of our process , we began to dedicate ourselves to the shock waves associated with each impulse ,” explained Dr Klock , now a doctor of metallurgy . “ We were convinced that , as part of the SIP , it was making an important contribution to the positive effect of the SIP on the process . We wanted to enlarge the raceway zone and break open blockages in the coke bed with strong shock waves . This would increase the permeability and consequently the efficiency of the blast furnace process with larger reaction surfaces .” “ The project team at AT . PRO tec explained what they intended to do ,” said Marcel Mokosch from Schubert & Salzer Control Systems . “ To generate impulses with even stronger shock waves , the high opening speeds had to be optimised still further to achieve extremely short opening times . In principle , sliding gate valves were goals over three years : firstly to improve the use of SIP on cupola furnaces through automation and secondly to enable the use of SIP on blast furnaces .” Within the framework of his doctorate thesis , Rainer Klock focused on research into the use on the blast furnace . First the physical and chemical processes that made the SIP successful on the cupola furnace were examined . The research group , consisting of employees from thyssenkrupp AT . PRO tec , thyssenkrupp Steel Europe and RWTH Aachen , wanted to understand the processes in the raceway zone of a blast furnace and how they would probably be affected by oxygen impulses in order to be able to transfer the technology from the cupola furnace to the blast furnace .
The SIP boxes are the result of many years of research and development : from the first tests at the Institute of Ferrous Metallurgy at RWTH Aachen , to the construction and optimisation of a prototype on the blast furnace in Schwelgern , to the installation of the complete SIP system during running operation . Photo : thyssenkrupp AT . PRO tec GmbH
26 Valve World August 2023 www . valve-world . net