EVAPORATOR Russian patent published in 2008 - IPC B01D1/22 

FIELD: chemistry.

SUBSTANCE: falling-film evaporator comprises vertical evaporating tubes secured in top and bottom tube sheets, preheating heat exchanger, with horizontal heating tubes arranged in vertical rows, mounted over the top tube sheet, with steam inlet, and separator. What is new is that evaporating tubes are arranged in in-line banks with n parallel rows of tubes and spaces between rows, while heating tubes of the preheater are arranged in n+1 vertical rows with pitch S equal to the space between rows of evaporating tubes. Vertical projections of axes of vertical rows of preheater tubes onto top tube sheet are offset as regards to evaporating tube rows by half-space. Besides, distributor may be designed as a rimmed perforated shelf, holes being arranged in rows along vertical projections of axes of the preheater heating tubes. Preheater steam inlet may be connected to secondary steam outlet of the apparatus separator. Preheater heating tubes may be tilted in the steam flow direction, tilt angle being at least 3°. Bottom heating tubes of each vertical row in the preheater may be provided with buldges, or rings abut with tube outer surface may be installed on tubes.

EFFECT: efficient long-term operation of apparatus is provided; design thereof is simplified; compactness and reduction in metal consumption are provided.

6 cl, 6 dwg