南美白对虾太阳能干燥能耗参数优化及中试.

Penaeus vannamei is the agricultural product with high nutrition and delicious taste. It is becoming increasingly popular in both domestic and foreign consumers and has realized its health benefits to people. But Penaeus vannamei is a kind of product with seasonal characteristics for harvest and has short storage period due to the vulnerability to infection by the microbes and spoilages during storage. As a result, we may suffer a great loss in the end. So the drying of Penaeus vannamei is becoming an important processing. The drying of Penaeus vannamei is mainly the traditional natural drying at present. It has many disadvantages: products being spoilt due to wind, rain, and dust, great loss due to animals and birds, and deterioration due to decomposition by fungi and insect. Further, the process will spend much time, need a lot of labors and occupy a large area for spreading the produce out to dry. So the natural drying under the open sky can not guarantee the quality of final products. It is difficult to meet the needs of industrial production. The drying using coal-fire needs a lot of energy consumption and causes heavy pollution during the drying process. Whatever, the artificial mechanical drying such as vacuum freeze-drying and hot-air drying is energy intensive and expensive, and it will ultimately increase the product cost. Solar drying system can process Penaeus vannamei in clean and sanitary conditions. It takes little time and energy, occupies fewer areas and improves product quality. Solar drying is efficient and can protect the environment. To reduce the Penaeus vannamei drying energy consumption and improve the drying quality, the effects of solar drying temperature, drying capacity and airflow rate on the drying process were investigated in the laboratory. The results showed that the increase of the drying temperature and airflow rate and the reduction of the drying capacity could improve the drying rate and shorten the drying time. In the later stage of drying, the effect of drying parameters on water activity was significant. Different drying temperature had significant effect on the texture of Penaeus vannamei after rehydration. The change of color was not so obvious with different drying parameters but had a big difference with raw Penaeus vannamei. The 3 drying parameters had significant effect on dry shrinkage and rehydration ratio. With the increase of temperature and airflow rate, the energy consumption had a significant increase. Increasing the drying capacity could improve the utilization of the energy consumption. The drying time also had much relationship with the energy consumption. Through laboratory experiment, the drying temperature was 45-55 ℃, airflow rate was 6-8 m/s, and drying capacity was 3-4 kg. And the relationships between the drying temperature, drying capacity and airflow rate and energy consumption were analyzed through the response surface method. The quadratic regression models were established. The optimal parameters were as follows: solar drying temperature of 53.40 ℃, airflow rate of 7.43 m/s, and drying capacity of 3.65 kg. Based on the laboratory test, the pilot scale test of solar drying of Penaeus vannamei was carried out. It have dried 100 kg Penaeus vannamei (69.5 kg after Salt solution pre-cooking) , got 38.16 kg final product and took 4.5 hours. The total energy consumption of solar drying was 549 827.05 kJ, including effective use of solar energy 379 619.05 kJ and the electric power 47.28 kW·h. The energy consumption was 0.68 kW·h/kg.Compared with electric heating drying,it could save 1.51 kW·h/kg energy consumption. Compared with coal drying, it could make 0.75kg/kg CO2 emission reduction. The results will provide the basis for the industrial production of Penaeus vannamei solar drying. [ABSTRACT FROM AUTHOR]