By-passing problems related to water cooling Case study for EAF

Transcription

1 Jakarta, 27 th June 2018 By-passing problems related to water cooling Case study for EAF Dr. Hans-Jörg Krassnig a joint company of: in co-operation with:

2 Company group structure 50.0 % 50.0 %

3 About Polymet Solutions GmbH - Introduction Definition of Polymet Polymetallic ore is per definition a mineral containing more than one metal. PolyMet Solutions works out the most efficient way, how to recover these metals for your profit. In general PolyMet Solutions covers the processing of the nonferrous metals.

4 Expertise of PolyMet Solutions AT A GLANCE Full-liner competencies for complete non-ferrous metals plants Highly innovative solutions combined with proven technologies (eg. ILTEC) Supply of state-of-the-art equipment (eg. TBRCs, valve stands etc.) Best process technology with in-house refractory engineering in 3D Unique pool of know-how on processes, refractories, and cooling for best furnace integrity and plant efficiency Studies for project development or plant optimization Project financing support

5 PolyTBRCs Next Generation PolyMet Solutions has further developed and successfully implemented the next generation of TBRCs for the copper and e-waste recycling industry. Electro-mechanical drives: Easy Installation and maximum flexibility. Plug & Play philosophy. Innovative oxygen/gas-combustion system to produce an intense, stable and compact flame with very efficient heat transfer capabilities and low exhaust volume flow. Improved heat transfer and reaction kinetics in refining and smelting processes High metals recovery and flexible process performance with good slag-metal separation Most modern calculation tools for process design including off-gas concept

6 Valve Racks Optimized Performance for all process steps High safety standard O 2 stainless steel Double blocking valves Pneumatic actuators Lines pressure transmitters ET200 distributed IOs Flow meters Rack oxygen/natural gas/pressurized air max. 50 Nm³/h NG@4 barg, max 150 Nm³/h O2@6 barg, max. 200 Nm³/h Air@6 barg, incl. double flow measurement flange parts low and easy maintenance systems

7 Furnace Integrity for long safe lifetime of the vessel Process and operation In depth process know how Practical data base of existing plants Joint know-how of SMS-PMS and Mettop Cooling Various cooling solutions within Mettop, PMS and SMS group Balanced approach ensuring long furnace life and minimized energy consumption Refractory Independency on suppliers best choice on refractories Highly competent experienced team

8 Cooling Technology Revolutionary new: Ionic Liquid Cooling Technology (ILTEC)

9 ILTEC Technology Why rethink cooling solutions? Over 200 documented (!!!) accidents caused by water coming into contact with liquid metal happen every year. Water + liquid metal = 1700 times volume expansion plus potential oxyhydrogen reaction.

10 ILTEC Technology Why rethink cooling solutions? Source: Case Studies of 23 Workplace Accidents and Their Causes, David N. Kobernuss, D&B Kobernuss Consultants, P.O. Box 440, Taberg, New York 13471; AISTech 2015 Proceedings, 2015 by AIST. Electric Arc Furnace (EAF) Explosions: A Deadly but Preventable Problem By Scott Ferguson and Nick Zsamboky, Systems Spray-Cooled

11 Ionic Liquid IL-B2001 Optimized properties Almost no vapour pressure below decomposition temperature Not flammable below decomposition temperature Non toxic Non corrosive

12 Ionic Liquid IL-B2001 Characteristic properties Symbol Value Unit Range Operation temperature [ C] ΔT = 150 C Short term stability 250 [ C] Decomposition temperature 450 [ C] Minimum operation temperature -10 [ C] Crystallization temperature [ C] Density ρ [kg/dm 3 ] C Specific heat capacity c p [J/gK] C Dynamic viscosity η 20 5 [mpa s] C Electrical conductivity κ [ms/cm] C Q [W] = ṁ [m/s] cp [J/gK] ΔT [K] Lower specific heat capacity can be compensated due to a higher temperature range and enables a heat transfer comparable to water (c p = 4.19 [J/gK]).

13 Ionic Liquid IL-B2001 Optimized safety Industrial scale tests with IL-B2001 introduced into liquid steel melt No reaction when liquid steel melt gets in contact with IL-B2001 Improved safety standards

14 Likelihood Negligible Unlikely Seldom Possibe Often ILTEC Technology Re-defining the term safety and becoming Best Available Technology (BAT) Cooling with IL-B2001 Water cooling Accidents happen from time to time When exchanging water by IL-B2001 -> explosion free environment that allows cooling in a safe and sound manner Probability remains at the same level BUT the extent of consequences can be tremendously shifted towards a decreased impact The diagram shows the path of becoming best available technology Insignificant Minor Significant Major Severe Consequences

15 ILTEC Technology Possible applications of ILTEC-Technology with IL-B2001 Substitution of water in existing systems Blast furnace taphole, formerly cooled with water New cooling applications Tuyere zone of Peirce Smith Converter or EAF shell - no cooling so far because of danger Possibility of heat recovery Sufficient heat transfer and higher outlet temperature of up to 200 C enable heat recovery

16 ILTEC Technology Hardware Main components: Tank filled with IL-B2001, the freeboard volume above the liquid level is purged with nitrogen to prevent hydration of the liquid through moisture in the air Two identical pumps (one for redundancy in case of breakage or malfunction) guarantee the flow of the IL through the entire pipe system Two heat exchangers to remove the heat to the secondary cooling circuit, again one in operation, one for redundancy Numerous measuring devices (digital as well as analogue) throughout the entire system to measure temperature, flow, pressure and differential pressure Variety of valves, adjusting wheels and shut-off devices for all different operation modes

17 ILTEC Technology References of industrial scale use

18 ILTEC Technology References of industrial scale use Number of installed applications: Application Benefit Supply lines Cooling of shaft part of plasma furnace Guaranteeing higher temperature inside the furnace for preventing corrosion from sulfuric acid Overall flow capacity Country Start Up 3 30 m 3 /h Norway January 2015 Blast furnace tap hole Increasing safety 2 30 m 3 /h Germany October 2015 Test for cooling EAF bottom shell Cooling of pipes of copper coolers during the casting process Cooling of connection flanges at the RH degassing vessel Cooling of a permanent charging lance and camera at TBRC converter Test at tuyere zone of copper converter Increasing the lifetime of refractory beneath bath level Increasing process safety and improve copper cooler quality Increasing process safety and prevent warping Increasing process safety and allowing a permanently remaining lance in TBRC Increasing lifetime of tuyere zone 2 20 m 3 /h Germany Tests performed in Summer m 3 /h Spain January m 3 /h Austria June m 3 /h Germany August m 3 /h Canada June 2018

19 Zinc Oxide Furnace Industrial scale application for side wall cooling at higher temperatures Cooling of furnace walls For preventing temperatures below the dew point, installed at Nyrstrar (Norway) and in operation since January 2015 No corrosion of the steel structure due to selective cooling to temperatures of 180 C and hence preventing of condensation of sulfuric acid Increase in lifetime of entire vessel

20 Blast Furnace Taphole Substitution of water in existing taphole Taphole cooling Blast Furnace ArchelorMittal, Bremen (Germany) since October 2015

21 RH Degassing Industrial scale application at a steel vacuum degassing system Cooling of all flanges as the connection parts between nozzle and lower part and lower and upper part for increased operating safety at Donawitz GmbH, Austria.

22 ILTEC Technology For tuyere zone cooling of converter Value Unit Individual supply lines Maximum pumping capacity 20 m 3 /h Capacity heat exchanger 400 kw Inlet temperature IL-B C Piping dimension facility DN50 Piping dimension supply lines DN40 Tank volume 250 dm 3 CFM copper cooling element, comprising of two individual copper parts, connected with a steel construction. In between the copper parts, the AlCr-tuyere bricks are inserted and in the final construction stage the castable refractory mass in casted upon the copper fingers. Start up in June 2018

23 ILTEC Technology For use in EAF

24 Concept for EAF Cooling solution for entire EAF ILTEC Roof and off-gas duct ILTEC Side Wall Panels Upper Shell ILTEC Side Wall Lower Shell

25 ILTEC Technology in EAF Upper shell cooling to increase safety Benefits: Increased safety because of a water-free furnace area Decreased damage in case of leakage due to the lack of volume expansion and explosion Fast leak detection in case of individual supply and supervision of each panel Avoidance of hydration of refractory of the bottom vessel in case of leakage Easy, fast and safe repair work in case of breakage

26 ILTEC Technology in EAF Upper shell cooling to increase safety

27 ILTEC Technology in EAF Upper shell cooling to increase safety Option 1 Option 2 Unit Supply lines cooling panels Total flow rate IL-B Temp. difference average (peak) 15 (30) 15 (30) C m 3 /h Cooling load average (peak) 2500 (5000) 2500 (5000) kw Inlet temperature IL-B C Outlet temperature IL-B2001 (peak) 65 (80) 65 (80) C Amount of IL-B kg

28 ILTEC Technology in EAF Lower shell cooling to increase vessel lifetime ILTEC Side Wall Lower Shell Benefits: Intensified cooling steep temperature gradient, less infiltration zone Less wear increased lifetime of refractory Decreased down time more productivity Decreased repair work/gunning lower production costs Increased safety for employees and systems Increased inner furnace diameter by decreasing refractory thickness

29 ILTEC Technology in EAF Lower shell cooling to increase vessel lifetime CFM cooler Slag spout Plate cooler ILTEC Side Wall Lower Shell Slag level Liquid steel bath Sill level Gas purging plug copper finger accretion layer castable refractory outlet copper back plate inlet

30 Freeze lining concept permanent lining ILTEC Technology in EAF Lower shell cooling to increase vessel lifetime Initial brick thickness [mm] Remaining brick thickness [mm] Remaining thickness [%] Area without cooling (1) Layer Layer Layer Area of copper panel (2) Layer Layer Layer Slag

31 ILTEC Technology in EAF Lower shell cooling to increase vessel lifetime

32 ILTEC Technology in EAF Off-gas duct cooling for heat recovery Benefits: Heat recovery due to outlet temperature of up to 200 C Bypassing corrosion problems in cold spots Increased safety for employees and systems (no water in the furnace in case of leakage)

33 ILTEC Technology in EAF Off-gas duct cooling for heat recovery

34 Summary ILTEC Technology is a proven technology ILTEC increases lifetime of refractory and reduced down time ILTEC allows to recover heat at 200 C ILTEC increases safety for employees and systems

35 ILTEC- Technology 35 Let s think out of the box!