Concentric annular heat pipe characterisation analysis for a drying application

•A new configuration of concentric annular heat pipes was characterised.•The entire inner space of the central tube was the condenser for ceramic drying, via screw conveyance.•11% filling ratio was optimum, giving sufficient fluid inventory for wick saturation.•Excellent isothermal conditions were achieved: 0.4–1.3 K.•Excellent global thermal resistances were achieved: 0.08–0.31 K/W.•At 302 W heat input, ceramic moisture was reduced from 33 to 21 wt% within 35 s.