Condition-Based Diagnostic Approach for Predicting the Maintenance Requirements of Machinery

Abstract

Wise maintenance-procedures are essential for achieving high industrial productivities and low energy expenditure. A major part of the energy used in any production process is expended during the maintenance of the employed equipment. To ensure plant reliability and equipment availability, a condition-based maintenance policy has been developed in this investigation. In particular, this project explored the use of vibration parameters in the diagnosis of equipment failure. A computer-based diagnostic tool employing an artificial neural-network (ANN) was developed to analyse the ensuing machinery faults, their causes and consequences. For various categories of this type of machinery, a vibration-severity chart (ISO 12372 / BS 4675: 1971) appropriately colour coded according to defined mechanical faults, was used in training of the ANN. The model was validated using data obtained from a centrifugal pump on full load and fed into the program written in Visual Basic. The results revealed that, for centrifugal pumps within 15 to 300kw power range, vibration-velocity amplitude of between 0.9 and 2.7mm/s was within acceptable limits. When the values rose to between 2.8 and 7.0mm/s, closer monitoring and improved understanding of the equipment condition was needed. The evolved diagnostic and prognostic model is applicable for other rotary equipment that is used within the same power limits

Predictive maintenance, its implementation and latest trends

“…29 However, in most of the cases, vibrations are not so straightforward to interpret and can be analysed by artificial neural network (ANN). 6,30…”

Elektri̇k Motorlarinda Uygulanan Bakim Yöntemleri̇ni̇n İncelenmesi̇, Karşilaştirilmasi Ve Uzaktan Eri̇şi̇mi̇n Kesti̇ri̇mci̇ Bakima Etki̇si̇

“…Fabrikalarda çalışanlar arasında "işletmeci" ya da "bakımcı" gibi bir ayrım yoktu. İşçiler sadece makinenin nasıl çalıştığını öğrenip işbaşı yapıyordu ve eğer arıza çıkarsa fabrikanın sahibi ya da o dönemde sadece büyük fabrikalarda istihdam edilen ve makinelerden anlayan teknik personel çağırılırdı (Thomas, 2007).…”

“…Uygulamada alınan her ölçümün direk yorumlanmasından ziyade genel bir titreşim seviyesi belirlenir ve bu seviyenin üzerindeki titreşime sahip ekipmanların titreşim grafikleri yorumlanır. Bu sonuçları yorumlamak için uzman personele ihtiyaç vardır ve iyi bir yorumlama için yapay sinir ağları gibi sınıflandırma ve tahmin yöntemlerinden yardım alınır (UGECHI, OGBONNAYA, LILLY, OGAJI, & PROBERT, 2009). Ekipmanların arızalarını yorumlayabilmek için Şekil 4'teki gibi bir uyarı spektrumunun hazırlanması gerekir.…”

Elaboration of an implementation approach of a condition-based maintenance through vibration analysis

“…In addition, diagnosis and data interpretation of the vibration measurement is difficult to perform correctly. It all depends on the organization, experience and competence to properly perform the analysis [1]. To successfully establish an effective monitoring policy, a rigorous approach is then necessary to overcome these difficulties and avoid the causes of failure of its implementation [2].…”