Improvements in the Treatment of Sea Water for Marine Boilers.
Year: 1889

page_text: Late of Application, 4th June, 1889
Complete Specification Left, 1st Mar., 1890-Accepted 5th Apr., 1890
.
PROVISIONAL SPECIFICATION.
· Improvements in the Treatment of Sea Water for Marine Boilers.
I, WILLIAM BRAMLEY, of 18 Clarence Street, Middlesbro on Tees, Yorkshire,
Analytical Chemist, do hereby declare the nature of this invention to be as
follows:-
་
.
The scale formed in Marine Boilers supplied with sea water, is due to the presence
of sulphate of lime. The object of this invention is to remove from the water,
previous to use, the sulphate of lime, whereby the prevention of scale is effected.
My invention consists in precipitating the lime by means of an alkaline sesqui
carbonate or bicarbonate, in the following manner:
Sea water is run into any suitable vessel to which is added a sufficient quantity of
sesqui-carbonate of soda to precipitate the lime. I recommend from 3 pounds to
3 pounds of sesqui-carbonate of soda per ton of sea water. After standing, say
from 12 to 24 hours, the greater part of the lime will be precipitated, which will settle
to the bottom of the vessel.
The water is then heated by means of steam, or otherwise, when the remainder of
the carbonate of lime will be precipitated the operation of heating the water may be
carried out in a second vessel. The precipitate (carbonate of lime) may be removed
by means of taps at the bottom of the vessels. The clear water is then separated for
use.
By this method the lime only is precipitated, leaving the magnesia in solution.
WILLIAM BRAMLEY..
COMPLETE SPECIFICATION.
c. Improvements in the Treatment of Sea Water for Marine Boilers.
I, WILLIAM BRAMLEY, of 18 Clarence Street, Middlesbro-on-Tees, Yorkshire
Analytical Chemist do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following stateinent
--
:
1
The scale formed in marine boilers supplied with sea water is due to the presence
of sulphate of lime. The object of this Invention is to remove from the water,
previous to use, the sulphate of lime whereby the prevention of scale is effected.
My Invention consists in treating sea water with sesquicarbonates or bicarbonates
of sodium, or potassium, so as to precipitate the lime only, leaving the magnesia
in solution. Any suitable mixture of bicarbonates with the simple carbonates of
sodium or potassium may be used. The quantity of bicarbonate in the mixture
should be sufficient to prevent the precipitation of the magnesia which the sea
water contains.
I recommend the use of sesquicarbonate. of sodium, it being cheaper than the
sesquicarbonate of potassium. The following may be taken as the quantity of each
precipitant required to précipitate the lime contained in 1 ton of sea water:
.
_ Sesquicarbonate of sodium (Na. CO. +² Na HCO)
3 pounds 702
Sesquicarbonate of sodium (Na. CO, +² Na HCO₂)
Sesquicarbonate of sodium, crystallised,
Bicarbonate of sodium
Sesquicarbonate of potassium (K, CO₂ +² KHCO₂)
Bicarbonate of potassium about
-
-
3 pounds 702
4 pounds 2 oz.
4 pounds 5 oz.
4 pounds 5 oz.
-
5 pounds

page_text: I prefer that the precipitant should be in a state of solution before being added to
the sea water.
This, in the case of the sesquicarbonates, may be made by dissolving in either hot
or cold distilled water.
The bicarbonates may be dissolved in cold, or slightly warm sea water; but I prefer
distilled water for the purpose.
In carrying out the Invention sea water is run into any suitable.vessel to which is
added sufficient sesquicarbonate of sodium to precipitate the lime.
The two solutions should be mixed as quickly as possible, & allowed to stand a
few hours; the solution is then heated by means of a steam coil or otherwise. By
allowing an interval of a few hours, a larger quantity of carbonate of lime is
deposited.
I find, however, that by increasing the weight of the precipitant, say 20% in
excess of that theoretically required the heating of the mixed solutions may be
proceeded with at once.
After heating, the clear solution is run off for use in marine boilers, or for
distillers, and the precipitate which settles to the bottom of the vessel may be
removed by means of a pipe provided for that purpose. In refilling boilers the
lime may be extracted by adding the precipitant to the sea water in the boiler
and heating; the precipitated carbonate of lime being removed by means of a sludge
pipe.
The temperature at which the carbonate of lime precipitates is about, from 160° F.
to 212° F. but more readily & completely by boiling.
To thoroughly remove the lime, and also to prevent the precipitation of the
magnesia, the sea water used for the process should be as cool as obtainable.
The vessel, or vessels, used for the process should be provided with a steam coil, or
pipe for heating or boiling the mixture. Also pipes for the purpose of running off
the clear solution & the removal of the precipitated carbonate of lime. This will
be facilitated by having the lower part of the vessel or vessels funnel shaped.
The bulk of the precipitated carbonate of lime, after settling, will be about 1 gallon
per ton of sea water treated.
A small vessel (capable of holding 3 or 4 gallons) should be provided for the
purpose of dissolving the precipitant."
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. The process for extracting lime from sea water by means of sesquicarbonates or
bicarbonates of sodium or potassium substantially as described.
2. The herein described process for treating sea water consisting in adding to the
latter, previous to use, and in a separate vessel sesquicarbonates or bicarbonates of
sodium or potassium, in substantially the quantities herein recommended, subsequently
heating (with or without an interval of rest) the mixture and separating the clear
solution containing the magnesia from the precipitated carbonate of lime as and for
the purposes herein described.
3. The employment of the solution obtained by treating sea water with sesqui-
carbonates or bicarbonates of sodium or potassium (as described) substantially as and
for the purposes herein set forth, whereby the prevention of scale is effected.