Maintenance & Reliability
Air compressors, gearboxes and hydraulic systems that use mineral oils are susceptible to varnish and sludge. The life expectancy of petroleum-based fluid is generally determined by the rate of oxidation. When oxygen comes in contact with a petroleum-based fluid, oxidation occurs. The problem is usually dealt with by dumping the fluid and flushing the system or purchasing a varnish removal filter. New fluid technology is eliminating this problem in a way that is much less expensive and more efficient. Suppliers have developed oil-soluble polyalkylene glycols that, when added to the oil in small amounts, eliminate varnish, reintroduce oxidation additives and decrease total acid number.
The goal of this project was to reduce the cost of maintenance and repair of the safety valves on all six boilers at ArcelorMittal Burns Harbor. Historically, the practice has been to disassemble and replace the parts for every valve annually. Studies show that the majority of valves that are disassembled do not require a total disassembly and repair. The U.S. Occupational Safety and Health Administration states that each company will establish a good engineering practice on the frequency and type of repair based on the historical data collected. By changing the frequency and type of testing, the time between repair has been increased from one year to two years.
In the iron and steel industry, the use of process analytics is required at several locations of the plant with different objectives. The measured data obtained from the analyzers are used to monitor and control the function and economic efficiency of the process, safety for personnel and equipment, and environment protection. Tata Steel has adopted many good practices to make gas analyzer measurement reliable. Until now, the number of interruptions has been reduced to two digits for every 40 gas analyzer measurements. Tata Steel worked to reach single-digit interruption for 40 gas analyzer measurements by the end of 2019.
Facilities depend on keeping critical assets running. Often this equipment is controlled by motor control centers (MCCs) that can last for decades — even beyond their original design life. However, equipment reliability, maintenance requirements and performance rely on proper application, operation and maintenance. This paper will examine the following areas of interest when assessing motor control centers: common wear items and maintenance guidelines for MCCs; upgrading to include new technology or expanding plant capacity; weighing cost considerations to maintain versus replace; and arc flash safety considerations when maintaining equipment.
Steel mill operators have long used condition monitoring to deliver critical, real-time equipment performance insights that can help reduce unscheduled downtime and maximize productivity. However, as condition monitoring programs continue to incorporate newer technologies, operators can gain even deeper insights that further improve equipment operation and maintenance decisions. Leveraging field and laboratory data, this paper will delve into some of these new technologies, including in-line oil sensors, and discuss how they can be integrated into a modern predictive maintenance program to deliver productivity and cost reduction benefits to steel mill operations.
In an competitive world, where the growing need to develop industrial production/productivity requires maximum performance, new technologies and equipment are required. Thus, reinforcement/retrofit of structural elements is needed. After some years, a structure can present pathologies that can be caused by new loading, design/assembly/fabrication deficiency or even lack of maintenance. Therefore, when it is necessary to accommodate new loads, it is crucial that the proposals contemplate the new loadings and a good structural condition. This paper reports on field experience during the work of repowering trusses with almost 20 years of use in an extremely aggressive environment.
Copper staves have now been used in blast furnaces for 40 years, and Primetals Technologies has had great success with this technology — in terms of the stave designs, the profiling of the blast furnace, and the operational strategies that can be used to support a 20-year campaign. However, a number of non-Primetals Technologies furnaces have suffered from challenges when implementing copper staves. This paper will reference some of the problems in bending and wear that customers have encountered, along with the solutions Primetals Technologies currently offers.