IMPROVED MEANS FOR PREVENTING THE CORRODING OF STEAM BOILERS
Year: 1862

page_text: LETTERS PATENT to Thomas Davison, of Belfast, in the County of Antrim,
Ireland, Engineer, for the Invention of "IMPROVED MEANS FOR PREVENTING
THE CORRODING OF STEAM BOILERS."
Sealed the 5th August 1862, and dated the 13th February 1862.
PROVISIONAL SPECIFICATION left by the said Thomas Davison at the
Office of the Commissioners of Patents, with his Petition, on the 13th
February 1862.
I, THOMAS DAVISON, of Belfast, in the County of Antrim, Ireland, Engineer,
do hereby declare the nature of the said Invention for "IMPROVED MEANS FOR
PREVENTING THE CORRODING OF STEAM BOILERS," to be as follows, that is to say:-
This Invention has for object to prevent the corroding of steam boilers in
which the same water is repeatedly reused, as in the case of marine and other
boilers working in connection with surface condensers. And whereas in such
boilers injurious corrosion in some cases takes place, and has been lessened
by frequently changing the water or a part of it, a means involving incon-
venience and loss of heat. It is by the present Invention proposed to prevent
such corrosion by introducing into the water a salt or salts; such as carbonate
of soda, potash, or lime, capable of neutralising the corrosive action of the
injurious agent present in the water.
The proportion of the salt required in any case will depend upon- the
quality of the water used in the boilers, upon the intervals at which it is

page_text: convenient to renew the water, upon the management of the boiler and engines,
and upon the quantity and kind of oil, grease, or other lubricant used in those
internal parts of the engine exposed to the steam, and from which it is carried
into the boiler by the steam and feed water. In general there may be added
to each gallon of water, from about ten ounces of carbonate of soda, or similar
salt, down to a quantity barely sufficient to render the water alkaline, and
equivalent proportions in the case of neutral or other salts.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Davison, in the Great Seal Patent Office on the
13th August 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
DAVISON, of Belfast, in the County of Antrim, Ireland, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirteenth day of February, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Thomas Davison, Her special licence that I, the said Thomas Davison,
my executors, administrators, and assigns, or such others as I, the said
Thomas Davison, my executors, administrators and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Chanuel
Islands, and Isle of Man, an Invention for "IMPROVED MEANS FOR PREVENTING
THE CORRODING OF STEAM BOILERS," upon the condition (amongst others) that I,
the said Thomas Davison, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said Thomas Davison, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement in writing, that is to say:-
My said Invention has for object to prevent the corroding of steam boilers

page_text: in which the same water is repeatedly reused, as in the case of marine and
other boilers working in connection with surface condensers. And whereas in
such boilers injurious corrosion in some cases takes place and has been
lessened by frequently changing the water or a part of it, a means involving
inconvenience and loss of heat, such corrosion is by the present Invention
prevented by introducing into the water a salt or salts (such as the carbonate)
of soda, potash, or lime, capable of neutralizing the corrosive action of tho
injurious agent present in the water.
The proportion of the salt required in any case will depend upon the
quality of the water used in the boilers, upon the intervals at which it is
convenient to renew the water, upon the management of the boiler and engines,
and upon the quantity and kind of oil, grease, or other lubricant used in those
internal parts of the engine exposed to the steam, and from which it is carried
into the boiler by the steam and feed water. In general there may be added
to cach gallon of water from about ten ounces of a carbonate salt, down to a
quantity barely sufficient to render the water alkaline and equivalent pro-
portions in the case of other salts.
For ordinary cases carbonates of soda or potash may be used, or soda,
potash, or lime in a caustic state; but special impurities may require the use
of phosphates or nitrates of soda, or potash.
Having thus particularly described my said Invention, and the manner in
which the same is or may be performed, I have to state that I do not restrict
myself to any precise details or proportions, but that what I consider to bo
novel and original, and claim as the Invention secured to me by the herein-
before in part recited Letters Patent is, preventing the corrosive action in
steam boilers, in which the same water is repeatedly used, by the use therein of
chemical substances substantially as herein-before described.
In witness whereof, I, the said Thomas Davison, have hereunto set my
hand and seal, this Twelfth day of August, in the year of our Lord One
thousand eight hundred and sixty-two.
THOS. DAVISON. (L.B.)