Metals Processing

Furnace Fuel Gas Pressure Control Producing steel is an energy intensive process. Utilizing byproduct gases as a fuel source is vital to the plant’s operational efficiency. These byproduct gases, which are recovered from blast furnaces and coke ovens, are commonly used as a mixed gas fuel source throughout the plant. Reheat furnaces can use mixed gas as the primary fuel source. Mixed gas feed lines can have variable incoming pressure and constantly changing gas demand due to heating cycles and exit door losses. This creates challenges in regulating air/fuel mixture and temperature within the reheat furnace. Reheat furnace operation directly impacts steel properties. Austenite grain structure, which is sensitive to time and temperature, directly effects the strength and mechanical properties of steel.  Minimal variation of incoming mixed gas pressure feeding the reheat furnace is critical to producing high quality steel. Accurate and responsive mixed gas pressure control enables efficient combustion for a controllable temperature profile within the furnace. Efficient combustion will reduce SOx emissions and gas consumption. This leads to stable slab heat up and soak, resulting in a more efficient furnace producing a higher quality finished product with fewer slab defects.  Literature Download the Furnace Fuel Gas Pressure Control Application Spotlight! Webinar Download

Coke Oven Cross Over Valve Pressure Control Coke ovens process coal into coke that is used as a fuel source in blast furnaces. Coke ovens run continuously and do not use air as a combustion source. The co-product gas exiting the coke oven is tightly pressure controlled to +/- 1 millibar. Excess pressure may cause the gas to be diverted from the co-product plant to atmosphere. Insufficient pressure may cause air to enter the oven, ruining the coke.  REXA  Linear  and  Rotary  Actuator’s 100% duty cycle capability is used to precisely control the coke oven collection line gas pressure.  Benefits: Precise Modulating Control  Reliability  90 degree normal, 355 degree maintenance rotation  Literature Download the Coke Oven Collection Control Application Spotlight! Webinar Download

Coke Plant Quenching Flow Control The coking process takes place over a span of 12-36 hours in a coke oven. Once pushed out of the vessel, the hot coke is often quenched with water to cool it before storage.  After the coke has been cooled, it is transferred to the blast furnace for use in iron making. REXA  Linear  and  Rotary  Actuators are used to effectively deliver quenching water to cool the coke by controlling the header pressure. Benefits: Precise modulating control  Reliability 

BF Steam Turbine RPM Control What is a Blast Furnace? The mining industry uses blast furnaces for smelting to produce industrial metals, such as pig iron. It is top-charged with iron ore, coke and limestone while huge quantities of air blast enter the bottom of the furnace from the blower. Oxygen within this air first reacts with the coke to produce carbon monoxide, which then reacts with the iron ore in a reduction reaction. Molten slag and iron leave the bottom of the furnace, while carbon monoxide, carbon dioxide and nitrogen leave the top. This is a continuous process, which if interrupted by unscheduled downtime, leads to increased costs.  Steam Turbine Control Solution Steam turbine speed control is a critical application requiring superior reliability. REXA Electraulic™ Actuators enable a smooth and reliable supply of cold blast “wind” flow to your blast furnaces.  The consequences of an actuator fail are devastating to plant iron making operations.  Loss of “wind” causes the molten burden in the furnace to drop, therefore resulting in damage to the furnace and an interruption of production.  Our self-contained Electraulic™ actuators require zero oil maintenance, making them virtually maintenance-free.  Benefits: Reliable Operation in Tough and Demanding Environments  Accurate (0.1%) and Repeatable Positioning  Smart Communications for Reviewing Actuator Health/History  The BF Turbo Blower has many applications that REXA can provide an immediate solution for including:  Inlet Guide Vane Control  Anti-choke Control  Blower Anti-Surge Control 

Blast Furnace Gas Pressure Control Background Steel making is an energy-intensive process. At a tier one integrated steel mill in Jamshedpur, India, the mill energy consumption required for steel production meets with power generation produced at the power houses on site. As their primary fuel sources, this steel mill uses by-product gases from blast furnaces and coke ovens.  What is Blast Furnace Gas? Blast Furnace Gas (BFG) is the key fuel source used at the combustion boiler to generate steam. This steam is used in various plant processes, as well as the steam generator, to produce electrical power. There are three power houses in the plant, each with five to seven boilers. BFG feed has two issues: a variable incoming flow rate and a low, fluctuating calorific energy constant.  Problem The key in producing high quality steam is to have minimal process variation of incoming BFG entering the boiler. Furthermore, greater process control enables efficient combustion and boiler product steam pressure – leading to stable-pressured steam.  Unfortunately, even with the use of smart positioners, pneumatic actuators lack precision due to the compressibility of air. REXA Electraulic™ Actuators, however, are able to work through this and provide more precise and accurate performance than pneumatic and traditional hydraulic technologies.  Solution Check out the full Blast Furnace Gas Pressure Control Application Spotlight below! Be sure to also view our webinar showcasing how our actuation technology can enhance this application’s efficiency.  Literature Download our Steel Mill Blast Furnace Gas Pressure Control Application Spotlight! Download

Gas Pressure Control – Baghouse A baghouse is an air pollution control device commonly used in steel mills. Baghouses remove particulates out of hot gases from various steelmaking processes.  The use of air dampers controls the gas pressure to optimize particulate recovery and process availability. Rexa actuators are used to precisely maintain vacuum pressure; even a slight positive pressure inside the bags can result in reduced cleaning efficiency.  Benefits: Precise modulating control  Reliability