The invention relates to a treatment technique of
sludge produced by
sewage treatment, in particular to a separated
thermal cycle sludge dry method and a device thereof. The method comprises the following steps: putting wet
sludge in a
drying tank for
drying, leading out the steam produced by
drying through a fan, letting the steam enter an
evaporator be condensed into water, letting the
peripheral water of tubes as
working fluid be subject to
evaporation to generate secondary steam, compressing the secondary steam by a vapor compressor to heat, then putting the secondary steam processed by heating as an outer heating source of the drying tank in a
heat transfer of the drying tank; supplying heat to sludge indirectly, letting the steam after the
heat supply be condensed into water, letting the water enter the
evaporator through the heat absorption of the tubes of the
combustion furnace to form a closed cycle of the
working fluid. According to the invention,
evaporation latent heat of water and heat value of non-condensable gas are fully recycled, to that the
energy consumption is minimized; and because of the
isolation effect of the
evaporator, the vapor compressor is separated from the products formed by anhydration of the sludge, so that the
system can stably run in long-term, and the
investment cost is greatly reduced.