Hydraulic system The hydraulic system provides motive power for almost all EAF movements including roof lower/raise, roof swing, electrode arms up/down/regulation/swing, furnace tilt forward/backward, slag door raise/lower and movement of any auxiliary systems such as the burner lance. The hydraulic system consists of a central reservoir, filters, an accumulator, hydraulic valves and hydraulic piping. As hydraulic fluid passes through valves in one of two directions within a given circuit, hydraulic cylinders are extended or contracted to provide movement of various mechanical components. Without sufficient fluid flow and pressure within a circuit, movement is impossible. Thus issues such as low fluid level, low accumulator pressure, system leaks, fluid degradation due to over-heating, solids build-up in valves or in hydraulic lines and wear in mechanical components can lead to poor system performance and in some cases, system failure.

Top Cooling water system Another system that is integral to EAF operation is the cooling water system. Typically, there are several cooling systems. Some operations require extremely clean, high quality cooling water. Transformer cooling, delta closure cooling, bus tube cooling and electrode holder cooling are all such applications. Typically, these systems will consist of a closed loop circuit, which conducts water through these sensitive pieces of equipment. The water in the closed loop circuit passes through a heat exchanger to remove heat. The circuit on the open loop side of the heat exchanger typically flows to a cooling tower for energy dissipation. Other water cooled elements such as furnace side panels, roof panels, offgas system ducting, furnace cage etc. will typically receive cooling water from a cooling tower.

The cooling circuit typically consists of supply pumps, return pumps, filters, a cooling tower cell or cells and flow monitoring instrumentation. Sensitive pieces of equipment normally have instrumentation installed to monitor the cooling water flow rate and temperature. For most water-cooled equipment, interruption of the flow or inadequate water quantities can lead to severe thermal over loading and in some cases catastrophic failure. Top Lubrication System Many modern furnaces have an automatic system that provides lubrication to various moving parts based on various "events" occurring during the tap-to-tap cycle. For example, some parts are lubricated every three roof swings, following tapping, etc. 10/3/2008 9:35 AM

Some components such as roller bearings are critical to furnace operation and are lubricated periodically by hand. Some hard to reach locations are serviced using tubing and remote blocks. Top AUXILIARY SYSTEMS In addition to the major mechanical systems associated with the EAF, there are also many auxiliary systems that are integral to furnace operation and performance. Oxygen lance system Over the past 20 years, the use of oxygen in EAF steelmaking has grown considerably. In the past when oxygen consumption of less than 300 cubic feet per ton of steel were common, lancing operations were carried out manually using a consumable pipe lance. Most modern operations now use automatic lances and most facilities now use a non-consumable, water-cooled lance for injecting oxygen into the steel. Many of these lances also have the capability to inject carbon as well.