@article{article_1867821, title={A Comparative Study on Steam Economy of Forward-Feed and Backward-Feed Multiple Effect Evaporators}, journal={Kocaeli Journal of Science and Engineering}, volume={2026}, pages={115–122}, year={2026}, url={https://izlik.org/JA57EG96GX}, author={Çobaner, Sinan and Ermiş, Kemal}, keywords={Çok etkili evaporatör, Geri besleme, İleri besleme, Buhar ekonomisi, Enerji analizi}, abstract={<p>Evaporation is one of the separation processes with high energy consumption in industrial applications, and the selection of flow configuration in multiple-effect evaporators plays a decisive role in overall system performance. In this study, the energy performances of forward-feed and backward-feed configurations in a four-effect multiple-effect evaporator are comparatively investigated. Within the scope of the case study, the concentration of a solution with an initial NaCl mass fraction of 10% is considered under operating conditions of 220 kPa inlet steam pressure and 10 kPa outlet pressure. The overall heat transfer coefficients are assumed constant and set to 2300, 1600, 1300, and 900 W/m²K from the first to the fourth effect, respectively. Using mass and energy balance models developed in the MATLAB environment, the steam requirement and steam economy of the systems are calculated for various feed temperatures, feed flow rates, and product solution solid concentrations. The results indicate that an increase in product solid concentration leads to an increase in total steam consumption in both feed configurations due to boiling point elevation. However, in the backward-feed evaporator, nearly %15 lower steam consumption and higher steam economy are achieved at the same product solid concentration, as the highly concentrated solution is evaporated in the effect operating at the highest temperature. An increase in feed flow rate results in higher steam demand in both systems; nevertheless, the backward-feed configuration exhibits a more stable steam economy over a wide range of flow rates. Increasing the feed temperature significantly reduces steam consumption from 6448kg/h to 4385 kg/h and improves steam economy from 2.33 to 3.42 in the forward-feed evaporator, whereas this effect is found to be limited in the backward-feed system. The findings demonstrate that forward-feed evaporators are more suitable from an energy efficiency perspective at high feed temperatures, while backward-feed evaporators are more advantageous for processes requiring high concentration increases and operating under variable flow rates. This study quantitatively highlights the critical importance of selecting the appropriate flow configuration based on process conditions in the design of multiple-effect evaporators. </p>}, number={17}