จำนวน Repository ( 286 )
Bananas drying performance with a developed hot Air dryer using waste heat from charcoal production process
The purpose of this research is to develop a hot air dryer using waste heat from a200 liter kiln for drying bananas and to investigate its drying performance. The main parts of the dryer consist of the drying chamber that has dimensions 0.71x0.83x.091 m3 the air circulation system and a heat exchanger which receives waste heat from the exhaust tube and kiln surface. The dryer was developed by designing a drying chamber on the top of a 200 liter kiln to reduce heat lost in the structure and an exhaust gas heat exchanger was developed using groups of copper tubes for increasing then heat transferred to the air. The drying performances were analyzed by measuring specific drying rates and specific energy consumption. Experiments were performed under different temperatures of 60 70 and 80℃ And at a constant velocity of 1.8 ms-1. Eucalyptus was selected as the heat source. Thirty kg of peeled bananas were prepared at an initial moisture content of 241.19±31.50% dry basis and were dried until to final moisture content of 48.47±10.46% dry basis. All experiments were carried out in duplicate. For temperatures of 60 70 and 80 ℃ the ave age specific drying rates were 0.085±0.0004 0.114±0.0009 and 0.1277±0.010 kg water h-1kesolid-1 and the average specific energy consumptions were 1.42±0.055 1.21±0.355 and 1.04±0.074 MJ/kg water respectively. Some dried bananas had burned at a temperature of 80℃ so at temperature of 70 ℃ was the optimal condition in this experiment. This produced good color a high specific drying rate and low specific energy consumption.
ผลของการใช้เปลือกทุเรียนผงทดแทนแป้งข้าวสาลีต่อคุณภาพของเค้กบราวนี
This research aims to study the physical and chemical properties of Cha-nee durian rind powder and using durian rind powder to replace wheat flour in brownie cakes at 1020 and 30% (w/w). Texture profile chemical composition and sensory evaluation of brownie cakes were analyzed. The results showed that durian rind powder contained 50% of dietary fiber. Brownie cake with durian rind powder showed significant decreasing of lightness (L*) and hardness while green-red component (a*) blue-yellow component (b*) toughness and cohesiveness values were significantly higher than the control sample (p<0.05). Proximate analysis of the products showed that brownie cake with durian rind powder had dietary fiber higher than control brownie cake sample significantly. At 30% replacing of durian rind powder brownie cake showed 18.2% increasing of dietary fiber as compared with the control sample. The acceptance score including appearance color odor flavor texture and overall scores of all samples in this study were not significant different. Results indicate that 30% of durian rind powder replacing wheat flour is appropriate for making brownie cake. Brownie cake with durian rind powder could be an alternative for food choice of healthy bakery product which are lower calorie (123.73 kcal per serving) and high amount of dietary fiber (6.37 g per serving). Moreover durian rind powder can be used as a food ingredient and source of dietary fiber in other food recipes for further study.
ผลของระดับความเร็วอากาศร้อนต่อการอบแห้งมะเขือเทศแช่อิ่มด้วยระบบสายพานลำเลียงร่วมกับอากาศร้อน
The objectives of this research were to study the effect of hot air velocity on the changes of the moisture content and temperature of preserved tomatoes undergoing combined conveyor system and hot air drying. Specific energy consumption physical properties in term of color and shrinkage and sensory evaluation of dried preserved tomatoes were also investigated. The preserved cherry tomatoes were dried at a drying temperature of 80oc and hot air velocity of 2 and 4 m/s until the moisture contents of the preserved tomatoes were lower than 18% wet basis. The experimental results showed that the hot air velocity had effect on the changes of the moisture content and temperature of preserved tomatoes. Specific energy consumption total color difference shrinkage percentage and sensory evaluation results of dried preserved tomatoes of the hot air velocity of 2 and 4 m/s were not significantly different (P>0.05).Moreover the dried preserved tomatoes obtained from this research had significantly lower sensory scores in term of color and appearance than those obtained from the local market (P≤0.05). However sensory scores in term of flavor texture and overall preference of the dried preserved tomatoes obtained from this research and the local market were not significantly different (P>0.05).
Fuel consumption monitoring system using control signal and characteristic correlations of fuel injector
Objectives of this study are (i) to investigate characteristics of a fuel injector and to establish the characteristic correlation for correcting the fuel injection rate calculated from the control signal of a fuel injector and (ii) to design and fabricate the fuel consumption monitoring system by measuring the control signal of fuel injector in conjunction with considering the obtained characteristic correlation to enhance accuracy of the measured fuel consumption rate. The characteristics of a fuel injector (maximum fuel injection rate of 270 cm3/min) e.g. engine speeds percentages of injector’s duty cycle and pressure differences between fuel rail and intake manifold were experimentally investigated on a test set in the laboratory. The study found that when the engine speed increased the fuel injection rate increased. When the percentages of infector’s duty cycle increased the increasing ratio was less than the one-to-one increasing ratio as a case of the ideal. Moreover when the pressure difference increased the fuel injection rate increased. After that the fuel consumption monitoring system was designed and fabricated based on the Arduino Mega 2560 microcontroller. Trip distance was measured by a GPS module. The real-time fuel consumption rate could be shown on a LCD display. All recorded data were stored onto a SD card for further data analysis. Finally the on-road-test validation was conducted by on the 2011 Mitsubishi Triton installed with the 4-cylinder gasoline engine with total displacement of 2351 cm3. It was found from that the average discrepancy of the measured fuel volume was ± 1.88% compared to the actual fuel volume obtained by measuring a decreasing volume of consumed fuel.
Effectiveness investigation of evaporative cooling using radiator for pre-cooling system
Due to the systems of mechanical vapor compression have a high energy consumption for air-conditioned space. Therefore the system of evaporative cooling presents as a promising alternative option for the air-conditioning system. Moreover the pre-cooling system is normally used to reduce an intake ambient air temperature before the air-conditioning system. As mentioned above this research aims to investigate the effectiveness of evaporative cooling system by using a car radiator for air per-cooling. In this research the commercial car radiator was used for cooling inlet ambient air by cooling water. The evaporative cooling system consisted of evaporative cooling panel with a maximum water rate of 40 lite/minute and a maximum air rate of 5100 m3/hr. The results show that most suitable water flow rate of radiator is 10 lite/minute and this radiator can make the differences of air temperature of about 8.9oC. Moreover the results also show that the effectiveness of evaporative cooling system could reach about 73.31% with a maximum sensible heat of 8.43 kW.