Water, Water Everywhere . . .
75
in a series of optimistic peaks interspersed by severe depressions as
the weaknesses of a particular process become painfully apparent.
There will be more to say about this in the next section,. after this
summary of various methods, both tried and experimental, which
are being considered for desalting the seas. ".
…«
«
‘
Generally speaking, the methods fall into three groups: processes
involving a change … of phase, for example from water to ice or—to
steam; those using membranes; and nally a loosely connected
group of chemical processes. They all have one thing in c0mrhoh‘:
they require energy to remove the salt. Since books have been written
"
about desalination alone, what follows can only be a sketch of the
__
basic principles involved.
r.
Processes involving a change of phase
-
,
Dz'sï2'llez‘ion. Apart from being the major process, distillation must
also be one of the oldest. The sailors of Ancient Greece knew about
it; there are references to the use of wooden stills on sailing ships;
and, with the advent of steamships, the process became rme
established. Essentially all that is involved is putting energy (heat)
into salt water and r€moving it from the Salt—free steam to give
water. What could be more simple? On board ship, the saving in
cargo and passenger space given by removing the need for water
storage is obvious; but on land the economics become quite differ—
ent. On land, energy is usually expensive and water cheap. There—
fore the guiding force in the
of distillation methods has
been to make the most economic use of available energy._
In lits most primitive _f0rm a
unit
of
nbthig more than a large kettle
cooling tubesloping
away"from the spout. But this Wastes that valuableeï—heaten'ergÿï" the
heat- «releasedi from the Condensirig steam is”lost£t0 the atmÔSphere,
*
A simple solution ina continuous process is to'Luse‘in—coming sea—‘Water to cdol the Steam. In
marine Units, sœamfwas allowed
to by—pa‘SS the “ship’s boiler and pass through pipes-submerged i'rà
pool efs‘ea—waær. fStiea1—distilling from" the
on other
pipes WhiCh‘“ carried Seat—Water to
type of distillation reached the peak of«its d6V610pm<êht
land
in the constructionby the British company G, and ]. Weir
plant
producing a *t0tâl of *2,24o,ooo Imperial gallons per
at
—
Aruba (I Imperial geillOn=r—zbï
‘
-
'
75
in a series of optimistic peaks interspersed by severe depressions as
the weaknesses of a particular process become painfully apparent.
There will be more to say about this in the next section,. after this
summary of various methods, both tried and experimental, which
are being considered for desalting the seas. ".
…«
«
‘
Generally speaking, the methods fall into three groups: processes
involving a change … of phase, for example from water to ice or—to
steam; those using membranes; and nally a loosely connected
group of chemical processes. They all have one thing in c0mrhoh‘:
they require energy to remove the salt. Since books have been written
"
about desalination alone, what follows can only be a sketch of the
__
basic principles involved.
r.
Processes involving a change of phase
-
,
Dz'sï2'llez‘ion. Apart from being the major process, distillation must
also be one of the oldest. The sailors of Ancient Greece knew about
it; there are references to the use of wooden stills on sailing ships;
and, with the advent of steamships, the process became rme
established. Essentially all that is involved is putting energy (heat)
into salt water and r€moving it from the Salt—free steam to give
water. What could be more simple? On board ship, the saving in
cargo and passenger space given by removing the need for water
storage is obvious; but on land the economics become quite differ—
ent. On land, energy is usually expensive and water cheap. There—
fore the guiding force in the
of distillation methods has
been to make the most economic use of available energy._
In lits most primitive _f0rm a
unit
of
nbthig more than a large kettle
cooling tubesloping
away"from the spout. But this Wastes that valuableeï—heaten'ergÿï" the
heat- «releasedi from the Condensirig steam is”lost£t0 the atmÔSphere,
*
A simple solution ina continuous process is to'Luse‘in—coming sea—‘Water to cdol the Steam. In
marine Units, sœamfwas allowed
to by—pa‘SS the “ship’s boiler and pass through pipes-submerged i'rà
pool efs‘ea—waær. fStiea1—distilling from" the
on other
pipes WhiCh‘“ carried Seat—Water to
type of distillation reached the peak of«its d6V610pm<êht
land
in the constructionby the British company G, and ]. Weir
plant
producing a *t0tâl of *2,24o,ooo Imperial gallons per
at
—
Aruba (I Imperial geillOn=r—zbï
‘
-
'