Production Process:

To maintain an efficiently operating unit and avoid failure of critical equipment, especially modern steel industry equipment, the focus has clearly shifted over the years, from Breakdown Maintenance, i.e. repairing the equipment after its malfunctions, to Preventive Maintenance, i.e. fixing the equipment according to planned maintenance schedule. The next trend was Computerized Maintenance Management Systems (CMMS), and the latest trend encompasses asset management and maintenance, supported by various methods of Condition Based Maintenance Systems (CBMS) and in-service inspection processes. CBMS or Predictive Maintenance methods are an extension of preventive maintenance and have been proved to minimize the cost of maintenance, improve operational safety and reduce the frequency and severity of in-service machine failures. The basic theory of condition monitoring is to know the deteriorating condition of a machine component, well in advance of a breakdown, for proactive maintenance. A conventional integrated steel plant has a vast array of equipment. The plant is a conglomeration of smaller units, each in itself complete and self-contained. These constitute Coke Ovens, Coal Chemicals, Sinter Plants, Furnace, Steel Melting Shops, Continuous Casting Machine, Tonnage Oxygen Plants, Plate Mill, Hot Strip Mill, Cold Rolling Mill, other secondary mills, Captive Power Plants and a host of other departments. Every piece of equipment needs special care and attention, characteristic to it. The Coal Chemicals unit has Gas Boosters and Exhausters that handle coke oven gas, a highly inflammable commodity, whereas Sinter Plant Blowers and Waste Gas fans handle air containing highly abrasive sinter dust. The Turbo Alternators of Captive Power Plant require round the clock vigilance involving a variety of parameters. Seemingly innocuous Forced Draft & Induced Draft fans of the Reheating Furnaces also assume significance because of their criticality in application. Failure of these fans may lead to cut down of Hot Strip Mill. Plate Mill production by 33 - 50 percent. Under the current business environment, cost competitiveness of steelmakers has assumed a priority role. As a global phenomenon, effective maintenance management has been accepted as the key to corporate strategy for reduced costs. This has led to integration of maintenance management function with production and business problems, not just equipment problems. With this realization that maintenance management can cost 35 - 40 percent of revenues and, in most cases up to 15 percent of unit production cost, steel companies are increasingly opting for new maintenance technologies which can be effectively and relatively easily implemented for reduced costs and increased profitability. According to industry estimates, a 10 percent reduction in maintenance costs translates to a 30 percent increase in profitability. From the previous discussion, the need for introducing new technologies to the steel production is definite. This study provided the factory with some state-of-the-art technologies which can be adopted into the steel production processes in order to improve the product quality, minimize the need for electrical energy and human resources, reduce maintenance time and cost, and increase reliability and real-time data accuracy. The Jordanian factory is located in Zarqa area, and employs (324) technicians, engineers and administration employees. The main function of the factory is to melt Scrap (collected used steel pieces) in an electric furnace of (30) tons capacity, then cast molten iron in molds to obtain steel billets. The steel billets are then manufactured in a sister company factory to produce concrete reinforcement steel bars (Rebar) in different sizes using rolling and extrusion, flat and square bars, and wire mesh. This factory, which was manufactured by a Turkish company, is a new one that started production in 2008. The current production capacity is around 10,000 tons of steel billets per month. Employing SCADA system into the melting and casting processes has a good impact on the product quality, minimizing the need for human resources, reducing maintenance time and cost; increasing reliability, and real-time data accuracy. This technology should provide the following:

Continuous (momentarily) monitoring of the state of the process and of the plant;

Displaying warnings and alarms, at a sufficiently high level of abstraction;

Giving advice as needed to the metallurgical management of the process.

Generating historical reports.

Nowadays, there are two main industrial processes to produce steel: The first one, which is known as integrated steel plant, produces steel by refining iron ore. This ore-based process uses a blast furnace. The other one, which is steel-making from scrap metals, involves melting scrap metal, removing impurities and casting it into the desired shapes. Although, originally the steel production in the electric arc furnaces (EAFs) was applied mainly to the special steel grades, the situation has changed with tap's size increase, and the high productivity that has been reached progressively. This has allowed significant cost reduction, diminishing consumption of energy, electrodes and refractory. At present, electric furnace combined with chemical additives, allows to make a very important part of the worldwide steel production on 1709 the basis of the massive recycling of the iron scrap. Under the current business environment, cost competitiveness of steelmakers has assumed a priority role. As a global phenomenon, effective maintenance management has been accepted as the key to corporate strategy for reduced costs. This has led to integration of maintenance management function with production and business problems, not just equipment problems. With this realization that maintenance management can cost 35 - 40 percent of revenues and, in most cases up to 15 percent of unit production cost, steel companies are increasingly opting for new maintenance technologies which can be effectively and relatively easily implemented for reduced costs and increased profitability. According to industry estimates, a 10 percent reduction in maintenance costs translates to a 30 percent increase in profitability.

This study reviewed the structure of the maintenance section in the factory in order to improve and develop the existing maintenance processes and reduce running production costs of consumed electrodes and electricity. The current bill of electricity consumption per month by the factory is around $0.5m, which is relatively high for a factory in a developing country. As mentioned above, the automatic control system and measures used to control the process of melting iron and steel scrap, was analyzed and reviewed in order to evaluate its effect on the mechanical and electrical maintenance of the factory. Many machinery parameters can be measured, trended and analyzed to detect imminent failure or onset of problems. Common among them are: Machinery vibration, Lube oil analysis including wear debris analysis, Infrared thermograph, Ultrasonic testing, Motor current analysis, Shock pulse measurement, etc. Additionally, operational characteristics such as flow rates, heat, pressure, tension, speed and so on can also be monitored to detect problems. In case of machine tools, product quality in terms of surface finish or dimensional tolerances is often an indication of problems. As all these techniques have value and merit, the application of any particular technique depends on the suitability and ease of implementation. The control systems of the Electrical Arc Furnace (EAF) used in the factory need the following improvement and development in order to reduce the final product cost. In order to achieve this aim, analytical methods were followed to improve steel production process in the EAF. In order to do so, the study was divided into two phases that are sequential yet synergistic. The first phase used traditional methods of work measurement drawn from industrial engineering practice, such as process definition, development of flow charts, and data collection via time-and-motion studies, to obtain a complete, quantitative understanding of current system operational procedures, workflow patterns, and location of productivity constraints. The second phase was built upon the understanding gained during the first phase. In the second phase, opportunities to improve throughput was identified, with particular attention to those opportunities requiring relatively low capital investment. The principal analytical tools to be used for this phase were the operations research techniques of project management, to identify both critical paths within work flow and utilization imbalances among system resources.

Improving Maintenance Management

A working definition for various types of maintenance actions is as follows:

Failure Maintenance: This relates to the policy of repair or replacement of a part or subsystem only upon failure of the named part or assembly.

Block Maintenance: This relates to the policy of repair or replacement of all parts on subsystems (block) at a predetermined interval of time.

Preventive Maintenance: This relates to the policy of repair or replacement of a subset of parts or subsystems, when another part of subsystem fails or is repaired/replaced after a certain length of service. Proper maintenance is essential to keep production equipment and capital assets at a state conducive to its output role in maintaining a level of production at a predetermined quality and quantity.

Maintenance costs typically average from 5% to 7% of the value of fixed capital assets, hence the economic implications of reducing maintenance costs are very vast. Data can be collected on costs of repair, downtime and availability percent statistics, usage of spares inventory, etc. This information can be used to set budgets, make historic comparisons and in general be used as control information. A sensible combination of failure maintenance and preventive maintenance will ensure that these objectives are met. The equipment failure characteristics often determine the worthwhileness of preventive maintenance activities. Equipment that fail randomly due to unexpected and inexplicable overstress, generally do not lend itself to preventive maintenance. Equipment that fails due to wear and tear may lend itself to preventive maintenance. Thus the 1st step in maintenance planning consists of analysis of failure characteristics of the subsystems comprising the total system. Forecasting of equipment failures in a stochastic system (probabilistic) is based on studying the past performance of the equipment and its subsystems, and assuming that these characteristics will hold in the future. Past data of equipment failures like time to fail are analyzed with a view to find a statistical distribution which closely resembles with a confidence limit of 90% or more the actual failure distribution of the subsystem. Once this is determined, methods of statistical sampling can be used to predict times to failure in any analysis. Among the most common failure distribution applicable to electromechanical systems are the Exponential distribution, Normal distribution, Log Normal distribution, Gamma distribution and Weibull distribution. Maintenance Procedure Program (MPP) system is a series of dynamically linked programs, each of which plays an important role in the effectiveness of the maintenance program. The system applies to both electrical and/or mechanical maintenance in the steel production line and provides the process of equipment inspection as well. The MPP is a manner of applying several maintenance concepts into a complete program. This program fully utilizes each concept while combining the efforts of all. Each program element can stand alone in its own right, yet together their strength is multiplied. The need of such a program came about after many attempts of installing only one concept of preventive maintenance. It became apparent that no one method would cover all the bases at any one time. Thus, building a structure which would take into account each facet of maintenance and combine the efforts of each into a master program became a reasonable task. In Maintenance Job Order System, information is fed into this system from the crew inspectors, the department inspectors, the nondestructive testing group, the operations department, and the electrical/mechanical maintenance group. This information is in the form of necessary work to be done as a result of inspections from the various sources. The equipment history files are also important inputs into the job order system. This history helps coordinate the jobs to be completed during planned outages. The next step is to open the job order. The job order can be opened or directed to the maintenance foreman or the departmental planner. If the order is directed to the foreman, the work is assigned to a crew for completion. Normally, work assigned to the foreman would be of a nature which could be completed with the line running or which would be done during an unscheduled interruption in the operation. If the job order is opened to the departmental planner, he will coordinate the job order with the central shops crafts department using a shops job priority system, the maintenance foreman, and the maintenance spares man. These people act as a team in organizing the manpower, spares, and other factors necessary to complete the required job during the planned outage. After the completion of the job, the job order is closed.

Discussion Questions:

1. Is it highly recommended to activate the other three facilities of the plant?

2. What improvements are you going to suggest in order to reduce the cost of production and maintenance in this factory?

3. Is programmable Logic Controllers may be proposed as improvement in operations?

4. Steel scrap is the most important raw material for electric steelmaking, contributing between 60% and 80% of total production costs. Is quick estimations of properties of different steel scrap grades important for improving the control and optimization of the EAF process?