An apparatus 100 for removing moisture from particulate material is provided. The apparatus 100 comprises a master chamber 102 having a master inlet 104 for the supply of gas to the master chamber 102. The apparatus 100 further includes a plurality of drying chambers 106 at least partially arranged within the master chamber 102. Each drying chamber 106 that is at least partially arranged within the master chamber 102 has a first end and a second end, wherein each drying chamber 106 is configured for directing a flow of gas-entrained particulate material between said first and second ends of the drying chamber 106. Each drying chamber 106 includes a plurality of dryer inlets for directing gas from the master chamber 102 into the drying chamber 106, for interacting with said flow of gas-entrained particulate material within the drying chamber 106.

This sludge drying device is characterised in that a gas entraining a mix of sludge and sand is recycled after drying (6) and separation (8) to be compressed (10) and circulate again through the dryer (6) acting as a heat exchange fluid. Compression has been performed to increase the dew point temperature of the gas containing the evaporated moisture, such that the latent heat of evaporation can be recovered by the drying gas. The required operating power can then be much lower than the required power for evaporating the moisture contained in the sludge, because most of this power is recovered.