Tube and shell type heat exchanger usually used in conjunction with condensation steam turbines. This is the equipment responsible for the “production” of vacuum in the exhaust of these turbine – with the purpose of maximizing the surge of energy available in the steam – and for returning the condensate to the system The vacuum is produced by the drastic reduction in specific volume resulting from steam condensation which, on coming into contact with the thousands of tubes cooled by the cooling water, is transformed into liquid and returns to the system to be transformed into steam again in the boiler, in an efficient, closed cycle without waste.