Method of multiple effect evaporation

Claim 2

flash evaporating a portion of said liquid in each evaporative zone by the action of a pressure which promotes evaporation thereof to produce both vapor and an unevaporated portion of said liquid at a reduced temperature,

Claim 3

for a plurality of evaporative zones, passing major portions of vapor produced in any given evaporative zone downwardly within one or more elongate chamber(s) extending downwardly from said given zone and maintaining the pressure within said elongate chamber(s) by controlling the pressure at the outlets of said chamber(s) to maintain said given evaporative zone at the pressure therein,

Claim 4

The method according to claim 1 wherein the elongate vapor chamber(s) from at least one of said evaporative zones pass through all that portion of said temperature gradient which corresponds to zones successive to and lower than that zone.

Claim 5

The method according to claim 1 wherein the elongate vapor chamber(s) from said given evaporative zone pass through less than that portion of said temperature gradient which corresponds to all evaporative zones successive to and lower than that zone.

Claim 6

the pressure within the elongate chamber(s) extending downwardly from evaporative zones successive to said given zone in said step (3) being maintained at progressively lower levels in the same manner as in step (3) to maintain said successive evaporative zones at progressively lower pressure levels thereby to maintain a pressure gradient decreasing downwardly through said successive zones,

Claim 7

The method according to claim 1 wherein the vapor after passing through said downwardly decreasing temperature gradient is additionally moved through and in indirect heat transfer relation with a cooling media thereby to effect further condensation from said vapor.

Claim 8

conducting the flow of unevaporated liquid through said successive zones so as to establish and maintain in said liquid, in response to said pressure gradient, a substantially downwardly decreasing temperature gradient, 6. the elongate chamber(s) from said given evaporative zone in said step (3) extending downwardly through at least a substantial part of that portion of said decreasing temperature gradient which corresponds to a plurality of evaporative zones successive to and lower than said given zone, the vapors in said given chambers moving in indirect heat transfer relationship with the unevaporated liquid in said substantial part of said temperature gradient, thereby to induce condensation of said vapor within said elongate chamber(s) and evaporation from said unevaporated liquid outside said chamber(s), to concentrate said unevaporated liquid,

Claim 9

The method according to claim 1 wherein the condensate formed in said elongate chamber(s) is recovered as a product.

Claim 10

The method according to claim 1 wherein, in said step (4), said major portions of vapor constitute substantially all the vapor produced in each said evaporative zone.

Claim 11

recovering a concentrated liquid product comprising said concentrated unevaporated liquid.