Falling film evaporator for concentrating liquids

Claim 2

A falling film evaporator for liquids comprising a vertically disposed vessel, a plurality of hollow evaporator tubes maintained in a vertical position within said vessel, at least two tube plates contained within said vessel, said tube plates being adapted to hold said tubes near their upper and lower ends and to subdivide said vessel into an upper chamber, a central chamber and a lower chamber so that said upper and lower chambers are in communication with each other through said hollow tubes, a lateral inlet for the introduction into said lower chamber of a stream of hot gas, a plurality of substantially parallel inclined baffle plates mounted in said lower chamber onto and between which baffle plates drops of liquid fall from the bottom ends of said tubes, said baffle plates being located below said inlet for said hot gas and inclined at an angle and in a direction away from the gas inlet such as to shield said droplets from said hot gases and to minimize disintegration of said drops into smaller droplets when they strike the baffles.

Claim 3

A falling film evaporator for liquids, comprising a vertically disposed vessel, a plurality of hollow evaporator tubes maintained in a vertical position within said vessel, at least two tube plates contained within said vessel, said tube plates being adapted to hold said tubes near their upper and lower ends and to subdivide said vessel into an upper chamber, a central chamber and a lower chamber so that said upper and lower chambers are in communication with each other through said hollow tubes a lateral inlet for the introduction into said lower chamber of a stream of hot gas, a pluRality of substantially parallel inclined baffle plates mounted in said lower chamber onto and between which baffle plates drops of liquid fall from the bottom ends of said tubes, and including at least one movable supporting rod provided in said lower chamber, said baffle plates being mounted upon and pivoted to said rod, and means for actuating said rod so as to alter the direction and angle of inclination of said baffle plates to a desired degree away from the gas inlet such as to shield said droplets from said hot gases and to minimize disintegration of said drops into smaller droplets when they strike the baffles.

Claim 4

A falling film evaporator for liquids, comprising a vertically disposed vessel, a plurality of hollow evaporator tubes maintained in a vertical position within said vessel, at least two tube plates contained within said vessel, said tube plates being adapted to hold said tubes near their upper and lower ends and to subdivide said vessel into an upper chamber, a central chamber and a lower chamber so that said upper and lower chambers are in communication with each other through said hollow tubes a lateral inlet for the introduction into said lower chamber of a stream of hot gas, a pluRality of substantially parallel inclined baffle plates mounted in said lower chamber onto and between which baffle plates drops of liquid fall from the bottom ends of said tubes, and including at least one movable supporting rod provided in said lower chamber, said baffle plates being mounted upon and pivoted to said rod, and means for actuating said rod so as to alter the direction and angle of inclination of said baffle plates to a desired degree away from the gas inlet such as to shield said droplets from said hot gases and to minimize disintegration of said drops into smaller droplets when they strike the baffles.

Claim 5

A falling film evaporator as claimed in claim 1, wherein said gas is air.

Claim 6

A falling film evaporator as claimed in claim 1, including means for reducing the inlet velocity of said hot gas stream in order to reduce entrainment of drops of liquid in said lower chamber.

Claim 7

A falling film evaporator as claimed in claim 4, wherein said means comprises an inlet duct for said hot gas stream, said inlet duct being of sufficiently large cross-sectional area to reduce the inlet velocity of said hot gas stream to a desired degree.