Yüksek frekans ısıtmalı vakumda kurutulmuş kerestenin bazı fiziksel ve mekanik özellikleri
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Dosyalar
Tarih
2019
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Düzce Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Klasik kurutma fırınlarında özellikle kalın kerestelerin kurutulması, kurutma kalitesi ve kurutma süresi açısından ideal değildir. Bu nedenle, kalın ve yoğunluğu yüksek ağaç kerestelerinin yüksek frekans ısıtmalı vakumlu kurutma methodu ile kurutulması önem kazanmaktadır. Türkiye'de ilk defa 27.12 MHZ frekansta yaklaşık 15 cm dalga boyunda yüksek frekans-vakumlu (Hf+V) kurutma metodu uygulanarak kurutma de-nemeleri gerçekleştirilmiştir. Bu çalışmada deneme materyali olarak yerli kaynaklar-dan seçilen meşe (Quercus robur) ve özellikle tüfek dipçiğinde kullanılan ceviz (Jug-lans regia), tam otomasyon kontrollü, yüksek frekanslı vakumlu kurutma fırınında keresteler kısa sürede kurutulmuştur. HF+V'de kurutulan keresteler ilgili standartlara göre bazı fiziksel ve mekanik özellikleri incelenerek kontrol örnekleri ile karşılaştı-rılmıştır. Yüksek frekanslı-vakumlu kurutma işlemi sonucunda söz konusu ağaç türle-rinde fiziksel özelliklerinde önemli bir değişme meydana gelmemiştir. Mekanik özel-liklerinde ise eğilme direncinde; saplı meşe kereste örneklerinde %12, adi ceviz ör-neklerinde %6, elastikiyet modülünde; saplı meşe örneklerinde %9, adi ceviz örnekle-rinde %7, basınç direncinde; saplı meşe ve adi ceviz örneklerinde %7; dinamik eğilme şok direncinde ise saplı meşe örneklerinde %20, adi ceviz örneklerinde %17; bir azal-ma olduğu tespit edilmiştir. Bu sonuçlara göre tüfek dipçiği gibi aşırı yüke maruz kalmayan kullanım yerleri için kurutma süresi dikkate alındığında ebatlı ve güç kuru-yan ağaç türlerinin klasik kurutma yöntemlerine göre yüksek frekanslı-vakumlu (Hf+V) kurutma yönteminin tercih edilebilir olduğunu göstermiştir.
In conventional drying ovens, the drying of especially thick lumber is not ideal in terms of drying quality and drying time. Therefore, it is important to dry thick and high density lumber by high-frequency heated vacuum drying. This scope of study, drying experiments have been performed by applying high frequency-vacuum (Hf+V) drying method at wavelength of approximately 15 cm at 27.12 MHZ frequency that this method implemented first time in Turkey. In this study, oak (Quercus robur) se-lected from local sources and walnut (Juglans regia) used in rifle stock were used as experimental material. These materials were technologically examined by drying the timber in a short time in a fully automated, high frequency vacuum drying oven. Some physical and mechanical properties of these tree species were compared natural drying and HF+V drying. As a result of the high-frequency-vacuum drying process, it was observed that the physical and mechanical properties; modulus of elasticity of 12% in oak timber samples, 6% in walnut samples; 9% for oak samples, 7% walnut samples, compressive strength; 7%, dynamic bending resistance 20% for oak and 17% walnut specimens; was decreased. According to these results for non-overloaded areas such as rifle stock can be using high frequency vacuum (Hf + V) drying is preferred in the conventional dry drying wood types method.
In conventional drying ovens, the drying of especially thick lumber is not ideal in terms of drying quality and drying time. Therefore, it is important to dry thick and high density lumber by high-frequency heated vacuum drying. This scope of study, drying experiments have been performed by applying high frequency-vacuum (Hf+V) drying method at wavelength of approximately 15 cm at 27.12 MHZ frequency that this method implemented first time in Turkey. In this study, oak (Quercus robur) se-lected from local sources and walnut (Juglans regia) used in rifle stock were used as experimental material. These materials were technologically examined by drying the timber in a short time in a fully automated, high frequency vacuum drying oven. Some physical and mechanical properties of these tree species were compared natural drying and HF+V drying. As a result of the high-frequency-vacuum drying process, it was observed that the physical and mechanical properties; modulus of elasticity of 12% in oak timber samples, 6% in walnut samples; 9% for oak samples, 7% walnut samples, compressive strength; 7%, dynamic bending resistance 20% for oak and 17% walnut specimens; was decreased. According to these results for non-overloaded areas such as rifle stock can be using high frequency vacuum (Hf + V) drying is preferred in the conventional dry drying wood types method.
Açıklama
YÖK Tez No: 579562
Anahtar Kelimeler
Ağaç İşleri, Wood Products, Ormancılık ve Orman Mühendisliği, Forestry and Forest Engineering
