Method and apparatus for saline water evaporation

Claim 2

Claim 1 wherein the carbon dioxide is evolved from the indirectly heated saline water while evaporating the saline water in a multistage flash evaporator to produce fresh water and brine.

Claim 3

Claim 1 wherein the carbon dioxide is evolved from the indirectly heated saline water by further heating it while precipitating scale-forming compounds; and the further heated saline water is evaporated in a surface heat exchange evaporator to produce fresh water and brine.

Claim 4

Claim 1 wherein a strong acid is added to the saline water to form dissolved carbon dioxide therein and initiate the evolved carbon dioxide: and thereafter discontinuing the addition of strong acid while normally recirculating evolved carbon dioxide to the saline water.

Claim 5

Claim 1 wherein the saline water is sea water and the carbon dioxide is added in substantially the minimum amount required to prevent the formation of scale during indirect heating of the sea water, the minimum amount of carbon dioxide increasing with the temperature of indirect heating and in parts per million of sea water being representatively 40 at 212* F., 55 at 257* F. and 215 at 302* F.

Claim 6

A process for converting saline water containing alkaline bicarbonates and carbonates to fresh water and brine, which comprises deaerating the saline water leaving a residual of air; adding a deoxygenating agent to the deaerated saline water and converting the air residual into an oxygen-free residual; indirectly preheating the deaerated saline water containing oxygen-free residual; evolving from the preheated saline water carbon dioxide, including that formed by the thermal decomposition of alkaline bicarbonates and carbonates, and oxygen-free residual; recovering evolved carbon dioxide and oxygen-free residual to include its carbon dioxide as collected carbon dioxide; recirculating to the saline water as the sole required carbon dioxide, said collected carbon dioxide, with retention thereof, including its oxygen-free residual, by the saline water, in proportion to the latter as required to prevent alkaline scale formation in the preheating thereof; and evaporating the preheated saline water in the course of or subsequent to evolving carbon dioxide to produce fresh water and brine.

Claim 7

Claim 7 wherein the deoxygenatiang agent is selected from among sodium sulfite, catalyzed sodium sulfite, ferrous sulfite and ferrous hydroxide.

Claim 8

Claim 7 wherein an acidic substance, selected from among a strong acid and carbon dioxide, is added to the saline water to form dissolved carbon dioxide therein and initiate the evolved carbon dioxide with included oxygen-free, gas residual; and discontinuing the addition of acidic substance while normally recirculating evolved carbon dioxide with included oxygen-free, gas residual to the saline water.

Claim 9

Claim 7 wherein collected carbon dioxide with included oxygen-free, gas residual is stored for any required use or as a byproduct of the process.

Claim 10

Claim 7 wherein the saline water is sea water; sulfuric acid is added initially to form dissolved carbon dioxide therein in substantially the minimum amount required to Prevent scale formation during the indirect heating, the minimum amount of sulfuric acid increasing with the temperature of indirect heating and in parts per million of sea water being representatively 25 at 212* F., 35 at 257* F. and 75 at 302* F.; and discontinuing the addition of sulfuric acid while normally recirculating evolved carbon dioxide with included oxygen-free residual to the sea water.

Claim 11

Claim 7 wherein the recirculation of collected carbon dioxide is discontinued while an acidic substance, selected from among a strong acid and carbon dioxide, is added to the saline water forming carbon dioxide therein; evolving the formed carbon dioxide and flushing collected carbon dioxide with it, whereby contaminants including excess included oxygen-residual are displaced from the collected carbon dioxide; and discontinuing the addition of acidic substance while resuming the recirculation of collected carbon dioxide with normally included oxygen-free, gas residual.