Karbon fiber destekli kabin kurutucuda elma kurutulmasının deneysel ve kuramsal incelenmesi ve işlemin enerjetik/ekserjetik değerlendirilmesi
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Tarih
2017
Yazarlar
Dergi Başlığı
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Cilt Başlığı
Yayıncı
Ege Üniversitesi, Fen Bilimleri Enstitüsü
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu tez çalışmasında, farklı şekillerdeki elma örneklerinin (plaka dilim, halka dilim ve küp), yeni bir ısıtma kaynağı olarak karbon fiber desteği kullanılan kabin kurutucuda (KFKK) 60 °C sıcaklıkta kurutulması işlemi deneysel ve kuramsal olarak incelenmiştir. Örneklerin şekil farklılığının kurutma süresi üzerinde etkili olduğu tespit edilmiştir (p<0.05). Elma örneklerinin farklı şekillerde kurutulması sonucunda bazı kalite özelliklerindeki (toplam fenolik madde içeriği, antioksidan aktivite, askorbik asit içeriği, renk özellikleri, yoğunluk ve dokusal özellikler) değişimin farklı olduğu belirlenmiştir (p<0.05). Genel olarak, kurutma işleminin ekserji verimliliği %9.53-%10.65 arasında ve geliştirme potansiyelinin 117.80-127.88 kJ arasında olduğu belirlenmiştir. Plaka ve halka dilim için 'Difüzyon Yaklaşım', küp için ise 'Wang ve Singh' modelinin kurutma davranışını karakterize eden en uygun modeller olduğu belirlenmiştir. Kurutma işlemi, kütle transferi ve eş zamanlı ısı-kütle transferi açısından büzüşmenin dahil olduğu ve ihmal edildiği durum için nümerik olarak (sonlu farklar ve sonlu elemanlar yöntemi) da incelenmiştir. Kurutma boyunca farklı şekillerdeki elma örneklerinde meydana gelen fiziksel değişimler (boyut, alan, hacim) görüntü alma/işleme yöntemi ile belirlenmiştir. Görüntü işlemeden elde edilen boyut değişimleri Deff hesaplamasına ve nümerik modellere entegre edilmiştir. İki farklı yöntemde de deneysel veriler ile iyi uyum gösteren modeller geliştirilmiştir.
In this thesis, the drying process of the apple samples having different shapes (slab slice, ring slice and cube) in the carbon fiber cabinet drier (CFCD) at 60° C was investigated, experimentally and theoretically. The shape difference of the samples was found to be effective on drying time (p<0.05). After drying of apple samples having different shapes, the changes on some quality characteristics (total phenolic content, antioxidant activity, ascorbic acid content, color properties, density, and textural properties) were significantly different (p<0.05).In general, it was determined that exergy efficiency was range of %9.53-%10.65 and development potential was range of 117.80-127.88 kJ of drying process. It was determined that the best model describing the drying behavior was 'Diffusion Approach' for slab and ring slices while it was 'Wang and Singh' model for cube slices. The drying process was investigated numerically (finite difference and finite element methods) for the cases of only mass transfer or simultaneous heat and mass transfer, where the shrinkage was included or neglected. The physical changes (size, area, volume) of apple samples having different shapes during drying were determined by image processing method. The dimensional changes determined from this method were integrated into Deff calculations, and numerical models.For both numerical methods applied, models having good agreements with experimental data have been developed.
In this thesis, the drying process of the apple samples having different shapes (slab slice, ring slice and cube) in the carbon fiber cabinet drier (CFCD) at 60° C was investigated, experimentally and theoretically. The shape difference of the samples was found to be effective on drying time (p<0.05). After drying of apple samples having different shapes, the changes on some quality characteristics (total phenolic content, antioxidant activity, ascorbic acid content, color properties, density, and textural properties) were significantly different (p<0.05).In general, it was determined that exergy efficiency was range of %9.53-%10.65 and development potential was range of 117.80-127.88 kJ of drying process. It was determined that the best model describing the drying behavior was 'Diffusion Approach' for slab and ring slices while it was 'Wang and Singh' model for cube slices. The drying process was investigated numerically (finite difference and finite element methods) for the cases of only mass transfer or simultaneous heat and mass transfer, where the shrinkage was included or neglected. The physical changes (size, area, volume) of apple samples having different shapes during drying were determined by image processing method. The dimensional changes determined from this method were integrated into Deff calculations, and numerical models.For both numerical methods applied, models having good agreements with experimental data have been developed.
Açıklama
Anahtar Kelimeler
Kurutma, Nümerik Modelleme, Görüntü İşleme, Enerji/Ekserji, Drying, Numerical Modeling, Image Processing, Energy / Exergy
