AN IMPROVED COMPOSITION POR PREVENTING INCRUSTATION IN STEAM BOILERS
Year: 1865

page_text: LETTERS PATENT to William Hewitt, of Brewer Street, Pimlico, in the
County of Middlesex, for the Invention of "AN IMPROVED COMPOSITION POR
PREVENTING INCRUSTATION IN STEAM BOILERS."
Sealed the 6th March 1866, and dated the 11th September 1865.
PROVISIONAL SPECIFICATION left by the said 'William Hewitt at the
Office of the Commissioners of Patents, with his Petition, on the 11th
September 1865.
I, WILLIAM HEWITT, of Pimlico, in the County of Middlesex, do hereby
declare the nature of the said Invention for "AN IMPROVED COMPOSITION POR
PREVENTING INCRUSTATION IN STEAM BOILERS," to be as follows:--
-
This Invention consists in combining tannic acid with unctuous animal
matters, such as leather, in the manufacture of an improved composition or
mixture suitable for preventing incrustation in steam boilers. The following
are the ingredients, matters, or substances which I propose to employ:
I take leather in any shape or form, or other materials, prepared, dressed, or
impregnated with bark or tan, such as is used by tanners in tanning leather,
and boil the same to a pasty consistence, adding, if necessary, tannic or gallic
acid, or both, in the proportion of about ounce of acid to 40 pounds weight
of the material; I then take this pasty mass and run it into moulds of
various shapes until it becomes solidified. The composition is then fit for

page_text: use, and can be introduced into the boiler either through the manhole or other
suitable aperture thereof at the rate of about one pound of the composition to
every nominal horse-power of the boiler. In practice I have found this
quantity last about six weeks, the composition becoming heated, its active
properties and virtues, as hereafter set forth, will be developed. Among the
novel features (or novelties) of this Invention, the Inventor dwell upon the
combination of tannic or gallic acid, or both, with unctuous animal matter in a
solid mass, for speedily removing incrustation from steam boilers when it has
formed, and for completely preventing the formation of incrustation when it
has not previously existed; and to ensure this result by the frequent
blowing off of the water in the boilers. In the first case the active agents,
i.e., the tannic and gallic acid and unctuous matter given off slowly by
the mass under the action of heat by dissolving the portion of incrustation
in immediate connexion with the metal of the boiler sets free the general
mass of incrustation, which can be removed from the boiler at the earliest
convenient opportunity; this action is found to be especially efficacious in the
removal of incrustation from those portions of the boiler, such as the tubes
and other parts, which are inaccessible to scrapers and other instruments.
These agents having removed incrustation are diffused over the inner face of
the boiler, and forming a thin liquid coating over it prevent the adhesion of
any sediment or other deposit thereto by preventing oxidation, and holding
in solution the salts adjacent. In the second, and perhaps more important
case, fresh portions of the aforesaid active agents of the composition are given
off from time to time or continuously, and being diffused over the inner
surface of the boiler by the continual action of the ascending and rotating
particles of water induced by the heat form a thin film of an unctuous liquid
over the inner face of the boiler tubes and other parts interposed between it
or them and the water, thereby preventing any deposition or deposit of
sediment or of salt on the metal. By using the composition in a solid block
the boiler may be blown off without fear of impairing the active properties of
the composition which remains, and which, so long as any portion of the block
shall remain, continues to disseminate efficaciously its active properties.
For the sake of convenience I can by the under-mentioned procees render
the solidified composition above set forth of a semi-liquid or jelly 'form by
first reducing it to small particles by any convenient means, and then adding
thereto about one part of the common soda of commerce to about twenty parts
of the first above-named composition, adding, if necessary, a small quantity of
tallow, grease, or other fatty matter, which I again boil until it assumes the
semi-liquid or jelly form I require, which when cool can be introduced into

page_text: boilers which do not present facilities for introducing thereinto the composition
in block. form or in.a solid mass.. In practice I have found this. semi-liquid
composition answer. well. in boilers when. used in the proportion of about one
pint per month of the composition to every nominal horse-power of the boiler.
The above is a convenient form of composition, but I prefer the solid block
form as being more satisfactory in. its action..
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Hewitt in the Great Seal Patent Office on the 10th
March 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
HEWITT, of Brewer Street; Pimlico, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of September, in the year of our
Lord One thousand eight hundred and sixty-five, in the twenty-nintli year of
Her reign,. did, for Herself, IIer heirs and successors, give and grant
unto me, the said William Hewitt, Her special licence that I, the said
William Hewitt, my executors, administrators, and assigns, or. such others
as I, the said William Hewitt,, 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 Channel Islands, and Isle of Man, an
Invention for "AN IMPROVED COMPOSITION FOR PREVENTING INCRUSTATION IN
STEAM BOILERS," upon the condition (amongst others) that I,. the said William
Hewitt, 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 William Hewitt, 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,, that is to say:-
This Invention. consists in combining tannic acid with unctuous animal
.:

page_text: matters, such as leather, in the manufacture of an improved composition, or
mixture suitable for preventing incrustation in steam boilers. The following
are the ingredients, matters,, or substances which I propose to employ
I take leather in any shape or form, or other materials, prepared, dressed, or
impregnated with bark or tan, such as is used by tanners in tanning leather,
and boil the same to a pasty consistence, adding, if necessary, tannic or gallic
acid, or both, in the proportion of about ounce of acid to 40 pounds weight
of the material; I then take this pasty mass and run it into moulds of various
shapes until it becomes solidified. The composition is then fit for use, and
¡can be introduced into the. boiler either through the manhole or other suitable
aperture thereof, at the rate of about one pound of the composition to every
nominal horse-power of the boiler. In practice I have found this quantity
last about six weeks. The composition becoming heated, its active properties
and virtues, as hereafter set forth, will be developed. Among the novel
features (or novelties) of this Invention the Inventor dwells upon the com-
bination of tannic or gallic acid, or both, with unctuous animal matter in.a
solid mass, for speedily removing incrustation from steam boilers when it has
formed, and for completely preventing the formation of incrustation when it
has not previously existed; and to ensure this result by the frequent blowing
off of the water in the boilers, in the first case the active agents, i.e. the
tannic and gallic acid and unctuous matter, given off slowly by the mass under
the action of heat by dissolving the portion of incrustation in immediate
connection with the metal of the boiler, sets free the general mass of incrusta-
tion which can be removed from the boiler at the earliest convenient oppor-
tunity; this action is found to be especially efficacious in the removal of
incrustation from those portions of the boiler, such as the tubes and other parts
which are inaccessible to scrapers and other instruments. These agents
having removed incrustation are diffused over the inner face of the boiler, and
forming a thin liquid coating over it prevent the adhesion of any sediment or
other deposit thereto by preventing oxidation and holding in solution the salts
adjacent. In the second, and perhaps more important case, fresh portions of
the aforesaid active agents, of the composition are given off from time to time
or continuously, and being diffused over the inner surface of the boiler by the
continual action of the ascending and rotating particles of water induced by
the heat, form a thin film of an unctuous liquid over the inner face of the
boiler tubes and other parts interposed between it or them and the water,
'thereby preventing any deposition or deposit of sediment or of salt on the
metal. By using the composition in a solid block the boiler may be blown.off
without fear of impairing the active properties of the composition which
.

page_text: remains, and which, so long as any portion of the block shall remain continues
to disseminate efficaciously its active properties.
For the sake of convenience I can by the under-mentioned process render
the solidified composition above set forth of a semi-liquid or jelly form by first
reducing it to small particles by any convenient means, and then adding
thereto about one part of the common soda of commerce to about twenty parts
of the first above-named composition, adding, if necessary, a small quantity of
tallow, grease, or other fatty matter, which I again boil until it assumes the
semi-liquid or jelly form I require, which when cool can be introduced into
boilers which do not present facilities for introducing thereinto the com-
position in block form or in a solid mass: In practice I have found this
semi-liquid composition answer well in boilers when used in the proportion of
about one pint per month of the composition to every nominal horse-power of
the boiler. The above is a convenient form of composition, but I prefer the
solid block form, as being more satisfactory in its action.
And in order to explain my said Invention more completely I now proceed
to describe the best means I am acquainted with, and which I have found
answer well in practice for carrying my said Invention into useful effect.
(2)
DESCRIPTION.
To make the before-mentioned composition into solid blocks, or cakes, or
pieces, I proceed as follows:-I take about one hundredweight of leather
cuttings, and place the same in a metal vessel, to which heat is to be applied,
then add thereto about 16 gallons of water, and boil the same until the leather
is melted or softened into a running state; the time necessary to effect this
will vary according to the quality of the leather; in a general way I have
found from five to six hours sufficient. When the leather has been sufficiently
boiled I then remove it with a shovel, and pour or run it into small wooden
boxes of different sizes, and leave it to cool and solidify; the composition is
then ready for use, and may be removed from the woden boxes by breaking
the said boxes. The liquor remaining in the copper after the softened leather
has been removed therefrom I use again in the next boiling of the same
quantity of leather, adding thereto a sufficient quantity of fresh water to allow
for evaporation and waste thereof.
To make the above-mentioned composition into a jelly I proceed as
follows:-I take about six gallons of the liquor the leather has been boiled in,
and mix therewith about six pounds of the above described solid block or cake
composition, and shave or cut the same into thin slices, and place it in a
vessel or pail made either of tin, iron, or copper, and afterwards place it in a

page_text: vessel full of water to boil, much in the same way commonly practised of
making glue. When the mass is in a boiling state I then add thereto about
one pound of the common washing soda, of commerce and one pound of
ammonia, keeping the whole well stirred during the boiling to prevent it
rising over, and when the mass is well mixed and settled down I remove it
and pour it into cans or casks ready for use. The jelly thus made may be
rendered more or less fluid by using more or less of the liquor in which the
leather has been boiled or during the boiling of the leather.
Having now fully described and set forth the nature and object of my said
Invention for "An Improved Composition for Preventing Incrustation in
Steam Boilers," together with the best means I am acquainted with. for
carrying the same into practical effect, I would remark, in conclusion, that
I hereby declare my Invention to consist in, and I claim combining tannic
acid with unctuous animal matters, such as leather, in and for the manu-
facture of an improved composition or mixture suitable for preventing
incrustation in steam boilers, as above described.
In witness whereof, I, the said William Hewitt, have hereunto; set. my
hand and seal, this Ninth day of March, in the year of our Lord One
thousand eight hundred and sixty-six.
WILLIAM HEWITT. (L.S.)