| 摘要 |
Heat-sensitive materials, such as tea, are dried with two or more separate streams of hot air generated from solar collectors, with some heat input from electrical heaters, steam-heated heat exchangers or solar-heated heat reservoirs. The air streams may be applied in succession, at different temperatures. Two solar heater may supplied with the same air stream in succession, and air exhausted from the dryer may be used to heat a reservoir, the heat from which is used to pre-heat air fed to a solar collector. |
