A plant for concentrating a tartaric acid solution comprising: - a first and a second evaporation unit, wherein said first and second evaporation units are arranged in series; - a pump for of feeding a diluted tartaric acid solution into said first evaporation unit; - a barometric condenser placed downstream of said second evaporation unit, - a system for feeding a first low-temperature vapor into said first evaporation unit, wherein each of said first and second evaporation units comprises: (i) a heat-exchange evaporation chamber, in which the first vapor comes into contact with the tartaric acid solution to be concentrated, (ii) a liquid-aeriform separation chamber, connected to a head portion of said evaporation chamber; wherein said first and second evaporation units are connected by a pipe for transferring the partially concentrated tartaric acid solution, placed at a bottom portion of said evaporation units (12; 14), and by a pipe for transferring a properly said aeriform phase from a head portion of the separation chamber of the first evaporation unit to the evaporation chamber of the second evaporation unit; wherein each of said first and second evaporation units further comprises a connecting portion, which connects the liquid-aeriform separation chamber to a bottom portion of said evaporation chamber, wherein said connecting portion comprises a column which extends along a vertical axis; wherein each of said first and second evaporation units further comprises a recirculation pump for the tartaric acid solution, operatively connected to said connecting portion for recirculating the tartaric acid solution from said separation chamber to said evaporation chamber. - a first and a second evaporation unit, wherein said first and second evaporation units are arranged in series; - a pump for of feeding a diluted tartaric acid solution into said first evaporation unit; - a barometric condenser placed downstream of said second evaporation unit, - a system for feeding a first low-temperature vapor into said first evaporation unit, wherein each of said first and second evaporation units comprises: (i) a heat-exchange evaporation chamber, in which the first vapor comes into contact with the tartaric acid solution to be concentrated, (ii) a liquid-aeriform separation chamber, connected to a head portion of said evaporation chamber; wherein said first and second evaporation units are connected by a pipe for transferring the partially concentrated tartaric acid solution, placed at a bottom portion of said evaporation units (12; 14), and by a pipe for transferring a properly said aeriform phase from a head portion of the separation chamber of the first evaporation unit to the evaporation chamber of the second evaporation unit; wherein each of said first and second evaporation units further comprises a connecting portion, which connects the liquid-aeriform separation chamber to a bottom portion of said evaporation chamber, wherein said connecting portion comprises a column which extends along a vertical axis; wherein each of said first and second evaporation units further comprises a recirculation pump for the tartaric acid solution, operatively connected to said connecting portion for recirculating the tartaric acid solution from said separation chamber to said evaporation chamber. (i) a heat-exchange evaporation chamber, in which the first vapor comes into contact with the tartaric acid solution to be concentrated, (ii) a liquid-aeriform separation chamber, connected to a head portion of said evaporation chamber; wherein said first and second evaporation units are connected by a pipe for transferring the partially concentrated tartaric acid solution, placed at a bottom portion of said evaporation units (12; 14), and by a pipe for transferring a properly said aeriform phase from a head portion of the separation chamber of the first evaporation unit to the evaporation chamber of the second evaporation unit; wherein each of said first and second evaporation units further comprises a connecting portion, which connects the liquid-aeriform separation chamber to a bottom portion of said evaporation chamber, wherein said connecting portion comprises a column which extends along a vertical axis; wherein each of said first and second evaporation units further comprises a recirculation pump for the tartaric acid solution, operatively connected to said connecting portion for recirculating the tartaric acid solution from said separation chamber to said evaporation chamber.