Improved design of tunnel dry facilities for dehydrating vegetables for increasing thermal efficiency

Top-mounted-fan adverse current tunnel dry facilities are widely used as the common way to dehydrate vegetables. However, its thermal efficiency is only 40%. By the analysis of energy loss on every production chain, two new tunnel dry facilities were designed .One was direct blowing adverse current tunnel dry facilities and the other was mixed flow tunnel dry facilities. Their thermal efficiency can come up to 58% and 68%, respectively. Several ways of raising thermal efficiency were also provided.