BULGUR ÜRETİMİNDE PİŞİRME İŞLEMİNE YÖNELİK ÖZGÜN BİR ISIL ANALİZİ: ENDÜSTRİYEL SÜREÇLER İÇİN TASARIM ÖNERİLERİ, ENERJİ VERİMLİLİĞİ VE ATIKSU AZALTIMI

Abstract

Bu çalışmanın ana katkısı, buğday pişirme işlemini özgün bir ısıl modelle izah ederek sunmak ve enerji-verimli bir pişirme kazanı için tasarım yöntemi önermektir. Küçük-ölçekli bir pişirme kazanı tasarlanmış ve modelin çeşitli çalışma şartları altında doğrulanması için bir deney düzeneği kurulmuştur. Geliştirilen model Engineering Equation Solver yazılımı kullanılarak çözülmüştür. Sonuçlar deneylerle kıyaslanmış ve iyi bir uyum elde edilmiştir. Isıl modelin doğrulanması ve büyük-ölçekli pişirme kazanlarına yönelik kullanışlı bir tasarım aracı olması için ayrıca bir hesaplamalı akışkanlar dinamiği modeli geliştirilmiştir. Pişirme işleminin enerji verimliliğinin, pişirme kazanının sarmal ısı değiştiricisi üzerindeki minimum ısı akısının çekirdekli kaynamayı (ısıtma elemanı yüzeyi ve doyma sıcaklığı arasında minimum ~5 °C farkla) karşılayacak şekilde başlatılmasıyla arttırılabileceği bulunmuştur. Enerji talebini azaltarak fakat nihai ürün kalitesini koruyarak, atıksuyun 5-günlük biyolojik oksijen ihtiyacı en az %50 oranında azaltılmıştır. Enerji optimizasyonu ve su geri kazanımı teknikleri yerine getirildiği takdirde buğday-su oranının 1,0−1,2'ye düşürülebileceği önerilmektedir. Tahmini ortalama özgül enerji tüketim hızının 400‒475 ±%5 W/kg (bir kilogram buğday için gerekli olan ısıl güç) arasında yer almakta, bu değer buğday-su oranının 1,0'a düşürülmesiyle ilaveten ~%25 oranında azaltılabilmektedir. Çalışmadan elde edilen sonuçların ısı ve gıda mühendisleri için endüstriyel pişirme kazanlarının tasarım uygulamalarında, daha az zararlı atıksu ile enerji optimizasyonunda ve buğdayın pişirilmesi için süreç kontrol stratejilerinde kılavuzluk edeceği düşünülmektedir

Keywords

• bulgur
• Buğday pişirme
• pişirme modeli
• enerji analizi
• kazan tasarımı
• atıksu

A NOVEL THERMAL ANALYSIS FOR COOKING PROCESS IN BULGUR PRODUCTION: DESIGN CONSIDERATIONS, ENERGY EFFICIENCY AND WASTEWATER DIMINUTION FOR INDUSTRIAL PROCESSES

Abstract

The main contribution of this study is to present a novel thermal model for analyzing the wheat cooking process and to propose a design procedure for an energy-efficient cooking pot. A small-scale cooking pot was designed and an experimental setup was installed to verify the model under various operating conditions. The developed model was solved using the Engineering Equation Solver software. Results were compared with those of the experiments and good agreement was obtained. Additionally, a computational fluid dynamics model was developed to verify the thermal model and have a useful design tool for large-scale cooking pots. It was found that the energy efficiency of the cooking process can be enhanced by initiating nucleate boiling (at ~5 °C minimum temperature difference between the heating element surface and saturation) which will supply the minimum heat flux on the helicoidal heat exchanger of the cooking pot. Lessening the energy demand but preserving the final product quality has decreased the 5-day biological oxygen demand of wastewater at least 50%. It is proposed that the wheat to water ratio can be reduced to 1.0−1.2 once the energy optimization and water recovery practices are satisfied. The estimated average specific energy consumption rate lies between 400‒475 ±5% W/kg (thermal power supplied for one kilogram of wheat) which can be reduced ~25% further by reducing the wheat to water ratio to 1.0. The results reported in the present study are expected to guide thermal and food engineers for the design applications of industrial cooking pots, energy optimization with less harmful wastewater and process control strategies for cooking of wheat.

Keywords

• Wheat cooking
• bulgur
• cooking model
• energy analysis
• cooker design
• wastewater

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