Abstract: The liquid concentrator has a vacuum vessel or chamber (1) in which a required vacuum is established. Within the common vessel or chamber (1) are provided concentrator components including a feed section (2), an evaporation plus condensing/section (3), a separation area (4), a baffle arrangement (5) and a vapour compressor (6). A seal (8) may be provided for the connection between the compressor (6) and a motor (7) mounted externally of the vessel or chamber (1). In another embodiment the motor (7) may also be mounted within the vessel or chamber (1). The invention avoids the cost and complexity of providing separate vacuum seals for each of the concentrator components.