Design Of Solar Drying System And Combined Drying For Ruditapes Philippinarum

China is a big country in marine aquaculture.In the whole industrial chain,the annual increase in total aquaculture production is about 20%,of which shellfish production accounts for about 80% of China's total marine aquaculture production.The Manila clam(Ruditapes philippinarums)annual export volume reaches 2 million tons.At present,the clam account for a considerable proportion of dry processing.The clams dry mainly adopts sun drying and hot air drying.Because of the high water content of the clam,the traditional drying method has problems of long drying time,high energy consumption,and difficulty in ensuring dry quality.Therefore,the development of high-efficiency and energy-saving drying technology is great significance to improve the clam drying level and quality.In this paper,a solar drying system of the clams was designed,which can realize reasonable lighting,thermal insulation and air circulation.It was found by the clam solar drying experiment,when the wind speed was 7m/s in cloudy weather.The rehydration rate was 108.56%,and the chromaticity difference was 28.63.The dried clam has a good rehydration rate;But at the same time,it was found that when the wind speed was 7m/s,the rehydration rate was 82.63%,the chromaticity difference reached 21,The chromaticity change obtained by drying the clams with a solar drying system was low.When the temperature difference was small,the wind speed has little effect on the rehydration rate of the clam.Better quality of dried clams by solar drying system.In this paper,the microwave vacuum and heat pump drying experiment of the clam was carried out to investigate the drying efficiency and quality of the two drying methods.The experiment found that under microwave vacuum drying conditions,the intermittent time was 10s-on/30s-off and the vacuum was 90 kPa.The dried clam has good product quality,the rehydration rate was 149.54%,and the chromaticity difference was 15.78,and the shape remains intact,clam does not collapse after rehydration.According to the heat pump drying experiment,when the drying temperature was 20 �C and the wind speed was 2 m/s,the dried clam has good product quality,the rehydration rate was 108.56%,the chromaticity difference was 23.02,and the shape remains intact.clam does not collapse after rehydration.The results of solar-microwave vacuum and solar-heat pump combined drying experiment showed that the quality of the combined dry clam was improved compared to solar drying.Clam rehydration rate of solar-microwave vacuum increased by 27.78%~42.88%,chromaticity difference decreased by 0.69~1.29;Clam rehydration rate of solar-heat pump drying increased by 9.64%~12.11%,chromaticity difference decreased by 1.23~4.22;It can be concluded that the multi-energy combined dry clam can improve the quality of clam,save energy and reduce energy consumption.The experiment showed that after the solar drying 8h combined with microwave vacuum and heat pump drying,the quality of dried clam was the best.The rehydration rates were 128.66% and 97.89%,respectively,and the chromaticity differences were 21.38 and 20.69,respectively.In summary,in order to ensure the all-weather drying,drying quality and efficiency of the clam,solar-microwave,solar-heat pump drying method can be used.This combined drying has promise.