The pilot plant was constructed at the Aquamill® factory. The key elements of the system shown in the figure above are the evaporator unit and the energy recovery steam compressor. The separation of the contaminated feedwater into steam and concentrate takes place via the Aquamill process.
Some of the steam in the evaporator is drawn off by the vapour compressor, compressed and then fed back to the heat exchangers as illustrated above. The compressed steam condenses in the heat exchangers thus producing the purified water. The energy given up by the condensing steam is transferred to existing steam in the drying zones thus achieving significant energy recovery, at the expense of supplying energy to the compressor. Analysis and operational experience has shown that the amount of energy needed to be supplied to the compressor is only a very small fraction of the energy recovered from the steam, which results in a highly energy efficient process.