WESTINGHOUSE PLASMA TORCHES

Transcription

1 PLASMA TORCHES For Foundry & Ironmaking Applications Commercially deployed High thermal efficiency Long electrodes life Low maintenance

2 Westinghouse Plasma Torches What is Plasma? Plasma is a high temperature, ionized, conductive gas created within the plasma torch. Plasma is created by the interaction of the gas with an electric arc. This interaction dissociates the gas into electrons and ions, enabling the gas to become both thermally and electrically conductive. The conductive property of the ionized gas in the arc region provides a way to transfer energy from the arc to the incoming process gas, and in turn, to the process or furnace. Of the methods used to generate heat for an industrial process, most are typically limited to the combustion temperature of the associated fuel. Westinghouse Plasma has overcome these limitations with the development of the plasma torch system. The plasma torch is an electric arc gas heater which can be utilized in high temperature industrial processes. As the process energy is provided by direct heat transfer from an electric arc, gases of widely varying chemical composition can be used. Plasma torches have the unique capability of increasing the energy of the process gas by 2 to 10 times higher than that of conventional combustion equipment. As such, the plasma torch offers distinct advantages over traditional methods. These advantages include control of process variables, such as precise temperature regulation, process gas flexibility and increased process operating temperature not typically possible by conventional means. A plasma torch consists of a closely spaced pair of tubular water-cooled electrodes. Inside each electrode is an electric arc discharge which is magnetically rotated at extremely high speeds. During operation, a process gas is injected into the torch header through one millimeter spacing between the electrodes. Sparkover between the electrodes initiates the arc discharge when the power supply is energized. The arc is immediately dispersed to the interior of the electrode by the incoming process gas. The arc current interacts with a magnetic field established by a solenoid field coil located around both upstream and downstream electrodes and rotates the arc at approximately 1000 revolutions per second. The combination of high arc rotating speeds and high gas flow rates provides superior heat transfer between the electric arc and the incoming process gas. This efficient process also helps maximize electrode life. The gas/arc interaction produces the superheated process gas and leads to the high thermal efficiencies obtained for the plasma torch and the superheated gas exits at the downstream end of the torch. The downstream electrode end is designed to protrude the refractory lining of the furnace or process reactor. The torch interfaces to the furnace or reactor by means of a mounting flange. The cooling water, process gas and power are connected to the torch at the upper (upstream) end of the external cover. All connections are designed for quick assembly and removal to minimize service effort. Complete servicing for the torch consists of electrode and electrode seal replacement and a water pressure leak test. Trained service personnel can perform routine maintenance in minutes. 2

3 Westinghouse Plasma Torches Driving production efficiency in steel making Westinghouse Plasma Corporation s (WPC) plasma technology has been developed for over 30 years with an estimated $100 million invested in research and development. The WPC technology was initially developed in collaboration with NASA for use in the Apollo space program to simulate space vehicle re-entry conditions. Alter NRG acquired WPC in 2007 and has further developed the plasma torches. WPC torches provide a clean source of heat that can improve efficiencies and improve environmental performance in many different industrial applications. Since 1980, WPC torches have been commercially deployed in over 34 different industrial applications for a wide variety of uses such as metals recycling, catalyst re-forming, heating of cupolas, and cleaning industrial gases. With rising costs of foundry coke and fuel oil, the WPC torch can effectively reduce energy consumption and cost by precisely managing heat input to the furnace. FURNACE APPLICATIONS As early as the 1980 s, WPC plasma torches have been deployed in industrial furnaces in various metals applications. Our customers include General Motors, SKF Steel, ALCAN, China Steel Co., Picklands-Mather Co., Cockerill Steel and Eldorado Resources Ltd. The largest, and longest running application was the GM cupola in Defiance, Ohio, which successfully utilized six (6) MARC- 11 plasma torches in a plasma assisted foundry cupola to make steel from scrap material for engine block castings. The plasma assisted cupola ran successfully for 22 years using the same plasma torches that were originally installed. This makes the WPC plasma torch and torch system the most industrially rugged and commercially acceptable offering on the market. The integration of our plasma torches in furnace applications have allowed our customers to benefit from higher blast temperatures lower coke utilization rates, higher furnace productivity, higher alternative fuel utilization and better control over furnace temperature and process chemistry. Plasma Melting Furnace, General Motors (GM), Defiance, Ohio, USA The unit was installed in 1989 at the General Motors Powertrain car plant In Ohio, USA as part of the foundry operation for the production of grey iron for the manufacture of engine blocks and other automotive castings. This was the first commercial scale plasma cupola built in the world, employing 6 x WPC plasma torch systems, operating at 1,750 kw each. The plasma cupola processed a feed charge that consisted of sprue, steel turnings, iron borings and fragmented steel scrap. Plasma Melting Furnace, Aluminum Canada Ltd. (ALCAN), Jonquière, Canada The plant was built in 1992 as an aluminium dross recovery furnace at ALCAN s plant at Jonquière, Canada. It uses 2 x plasma torch systems each operating at 850 kw. As an alternative to the conventional Rotary Salt Furnace (RSF) dross processing technology, the plasma dross processing technique reported an increase in material quality, reduced waste for disposal and excellent electrode life. Source: Juniper Consulting Services Ltd. Commercial deployment of Westinghouse Plasma Torches in Metals Applications SKF Steel used Plasma torches for commercial sponge iron production (1980) Cockerill Steel Co. used MARC 31 Plasma torches for superheating of blast air to reduce coke consumption (1981) Pickands-Mather Co. used - Torches for iron reduction and steelmaking (1984) General Motors Corporation - Torches for the production of cast iron in a commercial cupola (1989) ALCAN Aluminum dross recovery (research furnace) (1990) ALCAN - Aluminum dross recovery (commercial furnace) (1992) China Steel Co. Metals production research lab (1992) Undisclosed Metals Recycler H Metals melting (2010) Beijing Huanyu Guanchuan Plasma Technology Ltd. Steel and iron ore industry (2013) GM reported that... over ten years of operating experience demonstrated that the plasma technology is economically suitable for Iron melting. No major changes of traditional industry practices are required to operate plasma cupola systems. The plasma equipment can be operated and maintained by routine plant personnel 3

4 Furnace Integration of Plasma Torches Robust returns from increased furnace capacity and reduced coke usage Using the blast furnace as an example, WPC plasma torches can improve the profitability of the facility in two physical areas of the process scheme. BLAST FURNACE PLASMA TORCHES BLOW PIPE PLASMA TUYERE INJECTION PLASMA HOT BLAST PLASMA TORCHES STOVES PLASMA TORCHES PLASMA TORCH BLOW PIPE COAL INJECTION PLASMA TORCHES PLASMA TUYERE INJECTION HOT BLAST SUPERHEATING With plasma torches located at the tuyeres, the refractory lining of the blast main Hot blast superheating can occur at the stove outlet where hot blast (wind) is sent is not a limiting factor for increased wind temperature, allowing the operator to to the tuyeres. With wind superheating, the hot blast is superheated in the hot precisely control and increase the temperature of the furnace by several hundred blast main through mixing with high temperature plasma-heated air. This method degrees centigrade. This enables the raceway to reach higher productivity while increases wind temperature without shortening stove life or requiring the rebuilding improving the utilization of coal, natural gas or other alternate fuels. Pulverized coal injection rates can be increased by as much as 100 kg per tonne of hot metal, offsetting almost an equivalent amount of foundry coke and furnace productivity improvements of 4% or more can be realized. Benefits Enables rapid conversion of pulverized coal within the of stoves to operate at higher temperature. The increased hot blast temperature PLASMA TORCH decreases Benefits 50 C C increase in blast temperature can be achieved Coke rate reduction: 10 to 40 kg/ tonne of hot metal, more Pulverized coal injected blast furnaces can be further 4 Productivity increases of 4% or more can be realized 2 to 5 year payback is typical Consistent control over blast temperature allowing further optimization of the blast furnace optimized by offsetting an additional 100 kg/thm of coke with pulverized coal COAL INJECTION than offsetting the operating cost of the plasma torches limited raceway volume the foundry coke consumption of the facility. 2 to 5 year payback is typical

5 Redefining the Economics of Steel Making PLASMA TUYERE INJECTION Original Design Plasma-Tuyere Production Rate 4000 t/day 4150 t/day Temperature 1225 C 1450 C Plasma Torch Power N/A 18 MW Coke Usage 378 kg/thm 265 kg/thm Coal Usage 100 kg/thm 200 kg/thm Typical Payback 1-2 Years HOT BLAST SUPERHEATING Original Design Plasma-Heated Blast Production Rate 4000 t/day 4050 t/day Temperature 1100 C 1150 C Plasma Torch Power N/A 5 MW Coke Usage 491 kg/thm 485 kg/thm Typical Payback 1-3 Years 5

6 Plasma Torch Ratings High efficiency - low maintenance design PLASMA TORCH WPC s standard configuration operates in a range from 80kW to approximately 300kW. The current to the field coils in the is in series with the arc current. The does not feature independent control of the field coil current and arc current. PLASMA TORCH The torch power is controlled by changing either the arc current, field current or the process gas flow. Torch connections include quick disconnects for the air supply, cooling water and electrical connections to facilitate torch removal for inspection and maintenance. WPC has two standard configurations, a low power torch, the L and a high power torch, H. The low power L plasma torch operates in the range from approximately 350 kw to approximately 800 kw. The high power torch operates in the range from approximately 860 kw to 2400 kw. The maximum arc current of the plasma torch is 2000A. The torch uses two separate power supplies: one for the field coil and one for the arc. The arc current and the field coil current can be independently controlled. PLASMA TORCHES The WPC or plasma torches operate over electrical ranges based on the configurations below. Torch Type L MARC 11H Rated Min Power (kw) Rated Max Power (kw) MARC Air Flow (scfm) Air Flow (kg/hr) Thermal Efficiency 70% 85% 85% 81% Maximum Operating Current Maximum Operating Arc Voltage 400 ADC 1000 ADC 2000 ADC 650 ADC 860 VDC 950 VDC 1200 VDC 860 VDC Model Diameter Typical Length Weight inches mm inches mm Pounds MARC MARC 4.5 PLASMA TORCH Like the Marc 11, the MARC 4.5 torch power is controlled by changing either the arc current, field current or the process gas flow. Torch connections include quick disconnects for the air supply, cooling water and electrical connections to facilitate torch removal for ease of inspection and maintenance. The Marc 4.5 plasma torch has an operating power range of 280 kw to 530 kw. The MARC 4.5 is designed to have a variable custom fabricated length to fit a variety of different gasifier designs. The maximum arc current of the MARC 4.5 plasma torch is 650A. The MARC 4.5 torch uses two separate power supplies: one for the field coil and one for the arc. The arc current and the field coil current can be independently controlled. Plasma Torch WPC is a proven leader in its field in plasma gasification and the plasma torch system. Their systems have been proven commercially and represent significant market potential for the industrial furnace retrofits in China. China is the world s largest steel producer and this application of Westinghouse Plasma torches will be used to reduce the overall emissions profile and operating costs in the steel facilities. Mr. Huang Geng, Chief Technology Officer, Guanchuan 6

7 Plasma Torch Experience Commercially proven applications Date Customer Application Plasma Torch Systems 2013 Beijing Huanyu Guanchuan Plasma Technology Ltd. (GuanChuan) Industrial Furnace Applications related to Steel and Iron Industry 2010 Undisclosed Metals Recycler Metals Melting H SMS Infrastructure, Ltd. Commercial Vitrification of Common Hazardous Waste SMS Infrastructure, Ltd. Commercial Vitrification of Common Hazardous Waste Georgia Institute of Technology Laboratory Application Hitachi Metals Ltd. Commercial Gasification of MSW & Waste Water Sludge Hitachi Metals Ltd. Waste to Energy Facility Gasification of Auto Shredder Residue & Refuse Derived Fuel 2000 Undisclosed Client Hitachi Metals Ltd. Commercial Gasification of MSW Geneva Steel Corporation Commercial Production of Molten Iron for Steel Making Ishkawajima-Harima Heavy Industries Co. (IHI) Commercial Vitrification of MSW Incinerator Ash 1994 DuPont Corporation Materials Synthesis Development Ishikawajima-Harima Heavy Industries Co. (IHI) Research Lab for Vitrification of Incinerator Ash China Steel Co. Research Lab for Metals Production ALCAN (Aluminum Canada Ltd.) Commercial Aluminum Dross Recovery Furnaces ALCAN (Aluminum Canada Ltd.), Research Lab. For Aluminum Dross Recovery General Motors Corporation Commercial Cast Iron Production Consarc Corp. Research Center for Refining of Refractory Metals Eldorado Resources Ltd. Extraction of Uranium from Magnesium Fluoride Research Center Pyrolysis Systems Inc. Mobile Trailer for Liquid Toxic Waste Destruction Intermountain Power Co. Commercial Ignition of a Pulverized Coal Boiler Owens-Corning Fiberglass Research Lab. Studsvik Energiteknik Thermal Simulation of a Nuclear Reactor Core Meltdown Pickands -Mather Co. Metal Project Development of Plasma Iron Reduction and Steelmaking H H H MARC Westinghouse Research and Development Lab., 1981 Cockerill Steel Co. Commercial super-heating of blast furnace air to reduce coke usage MARC SKF Steel Co. Commercial Sponge Iron Production 1977 Westinghouse Research Jet Propulsion Lab. NASA Production of Solar Grade Silicon 1975 Westinghouse Research Arc Heater Project 1973 International Minerals & Chemicals Corp. Phosphate Defluorination Process 1971 Dow Chemical Corp. Hydrocarbon Process Research 7

8 Westinghouse Plasma Corp. Pioneer in plasma technology Technical Capabilities Quality Guaranteed Pilot Facility Westinghouse Plasma (WPC) has extensive background and experience in analytical, experimental, and commercial aspects of high temperature chemical and material heating processes have made WPC a leader in the development of plasma technology. Plasma can be applied to many industrial processes. To help predict process effectiveness, computer models have been developed for particle heating, heating with mass transfer, and heating with chemical reaction and mass transfer. By applying the results of the computer analysis, the design of a plasma process can be translated into commercial reactors. Additionally, with engineering expertise in heat transfer analysis, system design, system integration, experimental testing, auxiliary systems design and electrical, mechanical and chemical analysis, WPC has the capability to develop prototype designs in numerous process areas. WPC Torches are manufactured in the USA and can be delivered anywhere in the world WPC personnel have over 75 years of combined experience to install, troubleshoot and support the plasma torch systems WPC s continuous improvement process works to reduce capital and operating costs while improving power output ranges WPC provides aftermarket continuous client support and warranties for the torch systems WPC predictive modeling using VMGSim software creates preliminary designs for balance of plant configurations WPC has a 48 tonne per day pilot facility in Madison, Pennsylvania, USA Over 100 different varieties of feedstocks have been tested to provide baseline information for research and customers Given the high operating temperature of the plasma torches the facility has the capability to test a wide range of feedstocks The facility is equipped with state of the art equipment including real-time gas composition monitoring.