Climbing film evaporator

The invention provides a climbing film evaporator comprising an evaporation chamber and a separation chamber which are communicated through an air pipe; the evaporation chamber is internally provided with at least one group of heat-exchanging pipes; the heat-exchanging pipes are provided with a liquid concentrating and draining bar; the top part of the liquid concentrating and draining bar is in contact with the heat-exchanging pipes, the part below the top part is separated from the heat-exchanging pipes and pendent parallel to the heat-exchanging pipes; the side surface of the separation chamber is provided with a secondary-steam outlet pipe; and the lower end of the separation chamber is provided with a finished-liquid outlet pipe. The liquid concentrating and draining bar can concentrate the condensed water on the outer surface of the heat-exchanging pipes to the draining bar, so as to prevent the water film from forming on the outer wall of the heat-exchanging pipes, therefore, the working efficiency in the evaporation chamber is enhanced.