The invention discloses a composite dryer capable of recycling
flue waste heat. The composite dryer capable of recycling the
flue waste heat comprises a
drying channel section, a heat source section and a circulating fan section, the heat source section and the circulating fan section are arranged at two ends of the
drying channel section, and hot air generated by the heat source section passes through a hot-air
air channel and flows into the
drying channel section by means of drafting of the circulating fan section. The heat source section comprises a suction and draft fan, a
combustion furnace and a heat-exchange cavity plate, the heat-exchange cavity plate is formed by connecting a plurality of serially-connected or parallelly-connected cavity plates and sleeved at a
flue gas outlet of the
combustion furnace, a furnace ash settler is further arranged at the bottom of the heat-exchange cavity plate and integrally formed with the same, a flue waste-heat
heat exchanger is further arranged on the top of the drying channel section, a
flue gas pipeline is arranged on the sidewall of the flue waste-heat
heat exchanger, a tube pass of the
heat exchanger is communicated with the heat-exchange cavity plate of the heat-source section via the
flue gas pipeline, and
fresh air is communicated with the heat source section after entering a shell pass. The composite dryer capable of recycling the flue
waste heat has the advantages that circulating hot air and flue waste heat are recycled efficiently, use ratio of fire
coal is increased greatly, drying cost of agricultural products is reduced, and
environmental protection is benefited.