| 摘要 |
A large and economical type of multi-stack vertical tube evaporator (MS-VTE) is disclosed having units of multiple stacks of vertical tube bundles or stages mounted in a single vessel, and having its liquid feed pumped to the uppermost VTE bundle stack or stage and having the feed then cascading downward through the lower bundle stacks in series flow, and wherein all the tube bundles are heated with the same waste steam of no or low $-value, e.g. with turbine reject steam in parallel flow under vacuum into the steam-sides of all tube bundles in the unit through a common steam conduit; and wherein the feed liquid is progressively evaporated from stage to stage or stack to stack and the vapors produced in the tubes of each bundle during the partial evaporation of the feed are separated between the stacks and condensed by parallel flow into one or more condensers. Applied to seawater desalination in a co-generation procedure with a coastal power plant, this evaporator produces about one pound of distilled water per pound of turbine reject steam used under vacuum and applied to single-effect mode in one evaporator unit or several units mounted in a single vessel with a condenser, to substantially reduce the cost of such useful distilled water. When applied in a similar cogeneration procedure but in a multi-effect series mode of several such units, or multiple units, the rate of distilled water production can be increased several-fold based on the amount of turbine reject steam applied.
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