Breakdown maintenance

The allocation to industrial installations is based on sectoral emissions in the period 2000-2002 and on the emissions share of the installation in the sector s emissions in that period. This basic allocation principle is adjusted to accommodate several issues. Where individual unit data are not adequate, the installation receives its baseline capacity share using an average emissions benchmark for comparable facilities. Special provision is also made for cogeneration and process emissions, special circumstances during 2000-2002 (abnormal stops due to maintenance, breakdowns, changes in the installation, strikes, adverse weather etc.), and capacity increases after 1 July 2001 leading to an increase in emissions in excess of 20%. 

These sanbbers are found to be very useful during plant start-up after any long stoppage (during project comnussioning, after annual overhaul, or after any long maintenance breakdown) or when the process is upset—due to excess sulfur feed, disturbed converter temperatures, or a steam leak in the gas stream... 

There is little or no attention paid to preventive maintenance breakdown maintenance is the rule... 

If maintenance is performed, there are two principal maintenance strategies preventive and breakdown maintenance. These are not mutually exclusive, and may be combined even in the same piece of equipment. Take for example a private motor car. The owner performs a mixture of preventive maintenance (by adding lubricating oil, topping up the battery fluid, hydraulic fluid and coolant) with breakdown maintenance (e.g. only replacing the starter motor when it fails, rather than at regular intervals). 

Breakdown maintenance is suitable for equipment whose failure does not threaten production, safety or the environment, and where the cost of preventing failure would be greater than the consequence of failure. In this case, the equipment would be repaired either on location or in a workshop. Even with this policy, it is assumed that the recommended lubrication and minor servicing is performed, just as with a motor car. 

Preventive maintenance includes inspection, servicing and adjustment with the objective of preventing breakdown of equipment. This is appropriate for highly critical equipment where the cost of failure is high, or where failure implies a significant negative impact on safety or the environment. This form of maintenance can be scheduled on a calendar basis (e.g. every six months) or on a service hour basis (e.g. every 5,000 running hours). 

Cost Calculation. The main elements determining production cost are identical for fine chemicals and commodities (see Economic evaluation), a breakdown of production cost is given in Table 2. In multipurpose plants, where different fine chemicals occupying the equipment to different extents are produced during the year, a fair allocation of costs is a more difficult task. The allocation of the product-related costs, such as raw material and utiHties, is relatively easy. It is much more difficult to allocate for capital cost, labor, and maintenance. A simplistic approach is to define a daily rent by dividing the total yearly fixed cost of the plant by the number of production days. But that approach penalizes the simple products using only part of the equipment. 

A PPM program is needed to avoid equipment failures, utiHty outages, and production intermptions. From a cost savings angle it is extremely important to do preventive maintenance in order to avoid breakdowns. Periodic inspections and a good lubrication program uncover conditions that could lead to breakdowns. When problems are found eady, they can be taken care of without work intermption and costly repairs. Sometimes faciHty managers are so afraid of downtime that preventive maintenance is done too often. In other cases production does not allow adequate time to provide proper maintenance. 

Monitoring by Electromechanical Instrumentation. According to basic engineering principles, no process can be conducted safely and effectively unless instantaneous information is available about its conditions. AH sterilizers are equipped with gauges, sensors (qv), and timers for the measurement of the various critical process parameters. More and more sterilizers are equipped with computerized control to eliminate the possibiUty of human error. However, electromechanical instmmentation is subject to random breakdowns or drifts from caUbrated settings and requires regular preventive maintenance procedures. 

While comparison of the absolute capital costs and costs of electricity among different power systems is difficult and uncertain, the structure of these costs is rather typical, and the costs of component units are usually within known ranges. For an oxygen-blown IGCC power system, the breakdown of the capital cost for the four component units is air separation plant (11 to 17 percent), fuel gas plant (33 to 42 percent), combined-cycle unit (32 to 39 percent), and balance of plant (2 to 21 percent). The breakdown of the cost of elec tricity is capital charge (52 to 56 percent), operating and maintenance (14 to 17 percent), and fuel (28 to 32 percent). 

A quality service can be provided only by reliable equipment. This section seeks to ensure that effective routine inspection and maintenance programs are in place in order to detect defects before they cause accidents or breakdowns. 

Soft starting minimizes the starting mechanical and thermal stresses/shocks on the machine and the motor. It results in reduced maintenance cost, fewer breakdowns and hence longer operating life for both. Reduced starting current is an added advantage. 

Odor control by the addition of dilution air involves a problem associated with the breakdown of the dilution system. If a dilution fan, motor, or control system fails, the odorous material will be released to the atmosphere. If the odor is objectionable, complaints will be noted immediately. Good operation and maintenance of the dilution system becomes an absolute requirement, and redundant systems should be considered. 

Combining the practice of preventive maintenance and total quality control and total employee involvement results in an innovative system for equipment maintenance that optimizes effectiveness, eliminates breakdowns, and promotes autonomous operator maintenance through day-to-day activities. This concept known as Total Productive Maintenance (TPM) was conceived by Seiichi Nakajima and is well-documented in his book Introduction of TPM and is highly recommended reading for all involved in the maintenance area. 

The goal of any good maintenance program is Zero Breakdown. To achieve this goal, there are five counter measures. These are listed below ... 

The seheduling of maintenanee inspeetions and overhauls is an essential part of the total maintenanee philosophy. As we move from Breakdown or Panie maintenanee towards a performance based total productive maintenance system, total eondition monitoring and diagnosties beeomes an integral part of both operation and maintenanee. Total eondition monitoring and diagnostie examines both the meehanieal and performanee... 

Maintenance embraces regular inspection, periodic examination by competent persons , and repairs. Accidents may arise as a result of the lack of maintenance, during maintenance, and as a consequence of faulty maintenance. Preventive maintenance can be a legal requirement for, e.g., pressure vessels/boilers, lifting gear, power presses. A system is required for monitoring compliance witli scheduled preventive maintenance programmes, backed up by in-service inspection. Breakdown... 

Equipment used to process, store, or handle highly hazardous chemicals must be designed constructed, installed and maintained to minimize the risk of release. A systematic, scheduled, test and maintenance program is preferred over "breakdown" maintenance " that could compromise safety. Elements of a mechanical integrity program include 1) identification and categorization of equipment and instrumentation, 2) documentation of manufacturer data on mean time to failure, 3 ) test and inspection frequencies, 4) maintenance procedures, 5) training of maintenance personnel, 6) test criteria, and 7) documentation of test and inspection results. 

Breakdown maintenance means no preventive maintenance (i.e., failure is annunciated by the fact of failure). 

Leakage from maintenance operations, breakdown of equipment, or faulty operation of equipment... 

Number of days since last accidental release of hazardous material. This measure distinguishes between routine emissions (such as from storage tank vents, or low pressure steam discharges) and accidental emissions resulting from maloperation or breakdown. Events that might count would be safety valve releases, accidental releases into inappropriate drainage systems and unconfmed spills during maintenance. 

Simulation models aim to replicate the workings and logic of a real system by using statistical descriptions of the activities involved. For example, a line may run at an average rate of 1000 units per hour. If we assume that this is always the case, we lose the understanding of what happens when, say, there is a breakdown or a halt for routine maintenance. The effect of such a delay may be amplified (or absorbed) when we consider the effect on downstream units. 

To reduce the amount of information entered in the record, predetermined work of a planned maintenance nature can be entered in code form, while additional work or breakdowns may be more fully detailed. 

It follows that if the planned maintenance system is to be shown as effective, the number of breakdowns reported must reduce, irrespective as to whether it be a manual or computer system. A satisfactorily installed system allows the engineer to plan his department s work and, when necessary, action emergency items or additional work, without their being detrimental to the department s overall performance. 

Before committing the company or department to a system of planned maintenance, it is essential that there is a complete overview of the total demand on plant, equipment and resources and the benefits from the implementation of such a system, manual or computerized. Varying systems and/or part systems exist in almost every engineering maintenance department, which are due to company policy, changes in departmental staff or workforce, commitment of persons responsible, or, as is the situation in a number of instances, a previous breakdown, which the... 

Experience shows that some machines have more frequent failures than do others. Obviously, different failure modes have different frequencies of occurrence. This is usually described as mean-time-between-failure (MTBF) and expresses the probability of machinery failure and breakdown events as a function of time. This is of particular interest to the maintenance failure analyst and troubleshooter who have to grapple with the realization that some machinery failure modes appear slowly and predictably whilst others occur randomly and unpredictably. In most cases, both types of failures have been encountered. 

The existence of breakdown maintenance unquestionable. The maintenance activity is necessary to restore machinery equipment back to service after failure modes developed that were ... 

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