Falling film evaporator stripper

Claim 2

An evaporator for the separation of a relatively volatile material from a relatively nonvolatile material which evaporator comprises in combination: a vertical elongated outer housing having at its upper end an inlet opening to introduce liquid material to be evaporated and an outlet to remove volatile material, and at the other end a discharge opening to remove nonvolatile material, the housing containing therein a plurality of alternating discs and vertically disposed, tubular, internally heated jackets axially disposed and separated within the housing; the discs positioned transverse to the flow of material through the housing and convexly shaped to direct the flow of liquid material thereon toward the outer peripheral edge of each disc, each disc characterized by at least one generally axially located vapor flow passage therethrough surrounded by an upstanding collar to permit the flow of volatilE materials upwardly therethrough the flow passages of the discs defining in serial combination a generally unobstructed axial flow passage for vapor from one to the other end of the housing; the tubular jackets characterized by an enclosed annular tubular cavity, said jackets each having a substantially vertically disposed circumferential inner evaporating wall surface of sufficient vertical length that a majority of the heat transfer to to the mixture to be separated occurs on this surface and of less internal diameter than the disc directly below the tubular jacket and of greater diameter than the collar below the jacket, the jacket having an inwardly dished relatively short flange about its upper circumference, the outer peripheral lip of the flange extending beyond the peripheral edge of the disc directly above the flange, whereby fluid material from the upper disc is directed onto the flange and is rapidly formed into a thin downwardly moving film on the inner evaporating wall surface and then falls onto the lower disc; and means to introduce into and means to withdraw from each tubular cavity a fluid heat exchange medium thereby permitting fluid material introduced into the evaporator to be separated into relatively volatile and nonvolatile materials by continuously forming and reforming said nonvolatile material on the relatively cool horizontal discs as films and directly heating the material only as a relatively thin downwardly moving film on the inner evaporating wall surface of the tubular jacket.

Claim 3

The apparatus of claim 1 wherein the disc is a circular convex plate characterized by a single flow passage therein, and further having a smooth gradual slope from the outer periphery of the flow passage to the peripheral edge of the plate.

Claim 4

The apparatus of claim 1 wherein the housing is an elongated cylinder, and the diameter of the jacket is slightly less than the internal diameter of the cylinder, the lip of the flange having a gasket whereby the lip is placed in sealing and supporting engagement with the internal wall of the housing, and further wherein the flow passage within the disc is centrally located.

Claim 5

The apparatus of claim 1 wherein the means to introduce into and withdraw from each tubular cavity a heat exchange medium includes: elongated inlet and outlet conduits within the housing which conduits pass through the cavity of each tubular jacket and support each disc, the inlet conduit characterized by a flow passage within each cavity to introduce a heat exchange fluid into the cavity, and the outlet conduit characterized by a flow passage within each cavity to withdraw a heat exchange fluid from each cavity; means to connect the inlet conduit with a source of a heat exchange fluid; and means to withdraw said heat exchange fluid from the outlet conduit.

Claim 6

The apparatus of claim 1 wherein the collar extends upwardly from the surface of the disc to a distance of up to the bottom portion of the next higher tubular jacket surface.

Claim 7

The apparatus of claim 1 wherein the collar includes a cylindrical upwardly extending shield about a circular opening in each disc.

Claim 8

The evaporator of claim 1 wherein the cross-sectional area of the flow passages of the discs increases from the lower outlet end to the upper inlet end of the housing to handle the additional increase of vaporous material as evaporated from one to the other end of the housing.

Claim 9

The evaporator of claim 7 wherein the inner peripheries of the vapor flow passages lie in the surface of an inverted, axially disposed cone.

Claim 10

An evaporator which comprises in combination: an elongated vertical cylindrical outer housing having at its upper end an inlet opening to introduce material to be evaporated and an outlet to remove volatile materials, and at the other end a discharge opening to remove nonvolatile material, the housing containing therein a plurality of alternating discs and vertically disposed, tubular, internally heated jackets axially disposed aNd separated within the housing; the discs positioned transverse to the longitudinal axis of the housing and of a circular upwardly convex shape having a central generally axially located vapor flow passage therethrough surrounded by an upstanding collar, the flow passages of the discs defining in serial combination a generally unobstructed axial flow passage for vapor from one to the other end of the housing, and a gradual slope from the periphery of the central flow passage to the outer peripheral circumferential edge of the disc whereby fluid material thereon is caused to flow toward the edge of the disc; the tubular jackets characterized by an enclosed annular tubular cavity, said jackets each having an axially aligned inner relatively long cylindrical wall surface and an outer cylindrical wall surface and a relatively short inwardly dished flange about the upper circumference of the cavity, the outer lip of the flange having a diameter slightly less than the internal diameter of the housing and a gasket about the lip to place the lip in a sealing and support relationship with the internal wall of the housing, the inner wall surface of the jacket of sufficient vertical length that a majority of the heat transfer to the mixture to be separated occurs on this surface and having a diameter less than that of the disc below it and of greater diameter than the collar below the jacket whereby fluid material falling on the disc is directed to its outer edges, falls onto the flange of the tubular jacket below and forms a downwardly flowing thin film of material on the inner wall surface of the jacket; means to introduce into and means to withdraw from each jacket cavity a heat exchange fluid which means include elongated inlet and outlet conduits, opposingly mounted within the housing, each conduit passing through each jacket cavity, the inlet conduit characterized within each cavity by a flow passage in the upper portion of the conduit to introduce a heat exchange fluid into the jacket, and the outlet conduit characterized by an upper bleed passage and a lower condensate passage within each jacket, means to introduce a heat exchange fluid into the inlet conduit and means to withdraw a heat exchange fluid from the outlet conduit.

Claim 11

An evaporator which comprises in combination: an elongated vertical cylindrical outer housing having at its upper end an inlet opening to introduce material to be evaporated and an outlet to remove volatile materials, and at the other end a discharge opening to remove nonvolatile material, the housing containing therein a plurality of alternating discs and vertically disposed, tubular, internally heated jackets axially disposed aNd separated within the housing; the discs positioned transverse to the longitudinal axis of the housing and of a circular upwardly convex shape having a central generally axially located vapor flow passage therethrough surrounded by an upstanding collar, the flow passages of the discs defining in serial combination a generally unobstructed axial flow passage for vapor from one to the other end of the housing, and a gradual slope from the periphery of the central flow passage to the outer peripheral circumferential edge of the disc whereby fluid material thereon is caused to flow toward the edge of the disc; the tubular jackets characterized by an enclosed annular tubular cavity, said jackets each having an axially aligned inner relatively long cylindrical wall surface and an outer cylindrical wall surface and a relatively short inwardly dished flange about the upper circumference of the cavity, the outer lip of the flange having a diameter slightly less than the internal diameter of the housing and a gasket about the lip to place the lip in a sealing and support relationship with the internal wall of the housing, the inner wall surface of the jacket of sufficient vertical length that a majority of the heat transfer to the mixture to be separated occurs on this surface and having a diameter less than that of the disc below it and of greater diameter than the collar below the jacket whereby fluid material falling on the disc is directed to its outer edges, falls onto the flange of the tubular jacket below and forms a downwardly flowing thin film of material on the inner wall surface of the jacket; means to introduce into and means to withdraw from each jacket cavity a heat exchange fluid which means include elongated inlet and outlet conduits, opposingly mounted within the housing, each conduit passing through each jacket cavity, the inlet conduit characterized within each cavity by a flow passage in the upper portion of the conduit to introduce a heat exchange fluid into the jacket, and the outlet conduit characterized by an upper bleed passage and a lower condensate passage within each jacket, means to introduce a heat exchange fluid into the inlet conduit and means to withdraw a heat exchange fluid from the outlet conduit.