جستجوی مقالات مرتبط با کلیدواژه "مصرف انرژی" در نشریات گروه "صنایع غذایی"

In this study, energy and exergy indices for convective hot air drying of apple cubes were investigated and effect of the air parameters on them were assessed. Drying experiments were carried out at the air temperature levels of 45, 55 and 65 °C, and the air velocity levels of 1, 1.5 and 2 m s-1. Average values of energy utilization were obtained to be in the range of 0.324-1.543 kW. The minimum and the maximum values of specific energy consumption were obtained for drying at air temperature of 65 °C and air velocity of 1 m s-1, and at air temperature of 45 °C and air velocity of 2 m s-1, respectively. Average values of input exergy, output exergy and lost exergy were obtained to be in the range of 0.09106-0.52095 kJ s-1, 0.06401-0.46135 kJ s-1 and 0.02705-0.05960 kJ s-1, respectively. Average exergy improvement potential rate was increased with increasing air temperature and air velocity, and varied from 0.00804 kJ s-1 to 0.01175 kJ s-1.

Refractance window system is a novel moisture elimination system for production of high quality, dried or concentrated food products. Refractance window dryer can turn purees, juices and extracts of fruits, vegetables and herbs in to dried powders or flakes in a short time, using relatively low amount of energy and with minimum thermal damage. In this study an electric batch Refractance window dryer equipped with a thermostat, feed nozzle and a digital single phase kWh meter with 0.01 kWh accuracy, was made and its functionality was investigated.
Refractance Window system utilizes thermal energy of hot water through a polymeric film as a means to carry thermal energy to materials to be dehydrated. Dehydration process in this system is quick, self-regulating and under atmospheric pressure and it happens in temperatures below the temperature of the hot water used in the system so the thermal damage to the product is minimized. Water vapors are removed using an electric fan. To evaluate the dryer in this study, samples of carrot puree, aloe-vera gel, catchup souse and tomato juice was dehydrated using the Refractance window dryer and a laboratory freeze dryer and the dried products were compared. Results showed that Refractance window dryer can produce high-quality products with equal or higher quality than freeze dryer, using less energy and with higher energy efficiency and therefore less undesirable environmental impact.

The main objective of this study is to design and construct the new, spouted bed dryer, for food drying sensitive foods specially. For this purpose, firstly a new design of dryer was planned to achieve the maximum efficiency and flexibility for liquids and solids drying. After constructing and initial setup of spouted bed, basic experiments such as investigation of an inert particles motion, pressure drop, energy consumption were conducted and optimal system requirements for two particle size (5.8 & 7.8 mm) were determined. The results indicated that changes in pressure drop in the dryer chamber containing inert particles are followed from the Ergun equation. Energy consumption in this system is variable in the range of 3-8 kW per hour. Also results reveals that the energy consumption of the new design of spouted bed dryer is less than the spray dryer for liquid foods drying.