The Manufacture and Application of a Certain Fluid Preparation for Preventing or Lessening Corrosion and Pitting in Steam Boilers.
Year: 1889

page_text: Date of Application, 8th June, 1889
Complete Specification Left, 7th Mar., 1890-Accepted, 12th Apr.,
1890
PROVISIONAL SPECIFICATION.
The Manufacture and Application of a Certain Fluid Preparation
for Preventing or Lessening Corrosion and Pitting in Steam
Boilers.
We, JOHN BRADBURNE DODDS, of No. 13 Dean Street, Newcastle-on-Tyne, in the
County of Northumberland, Analytical Chemist, and JOHN REED FOTHERGILL, of
No. 1 Bathgate Terrace, West Hartlepool, in the County of Durham, Superintending
Marine Engineer, do hereby declare the nature of this invention to be as follows:-
As is well known corrosion and pitting occur in the interiors of steam boilers, and
various means have been resorted to with the view of obviating the evil. One of
these, which is adopted especially in marine boilers, consists in placing inside the
boiler, either suspended in trays or hangers, or fastened to and in metallic contact
with the metal of the boiler, or applied in some other manner or form, slabs, blocks,
or plates of zinc. These have been found to exercise a beneficial influence to a certain
extent, but are open to the objection that the whole of the zinc required must be
placed in the boiler before closing up and filling the boiler with water; it results that
during the first few days steaming there is a large quantity of zinc very active, then
from various causes (for instance oxidation) the zinc ceases to be effective just when
it is required to act most efficiently, that is to say, as the source or cause of corrosion
becomes inore active which it does the longer the boiler is under continuous steam.
Now in order to obviate this difficulty according to our invention we manufacture
zinc solution as hereinafter described, and apply the same to steam boilers at regular
or stated intervals, either with the feed water, by a separate pump, or by injection, or
by other similar or suitable methods, by which means we are enabled to provide and
maintain a steady constant and effective preventive to corrosion and thereby to preserve
the boilers from corrosion and pitting. Or the solution may when thickened as herein-
after described be used as a wash or paint, applied by a brush or in some other
convenient and similar manner to particular corroded or pitted places in the boiler
whilst the water is out of the boiler or to the material of new boilers during con-
struction.
In the manufacture of the zinc solution, we add to water suitable quantities of
sodic hydrate, (Na HO) or potassic hydrate (K HO) and of zinc (Zn) rendered
sufficiently small to be readily soluble, and we heat the whole until the sodic hydrate
or potassic hydrate, as the case may be, has dissolved its full proportion of zinc, after
which more water is added and the whole allowed to cool and settle, and the clear
liquor is drawn off for use according to our invention; or instead of metallic zinc as
described, galvanised iron may be used, cut into convenient sized pieces to facilitate
the operation. The sodic hydrate, or potassic hydrate as described, will dissolve the
zinc and leave the iron intact; or zinc salts may be used, in which case ammonic
hydrate (H NHO) could be substituted for sodic or potassic hydrate.
In carrying out this invention satisfactory results may be obtained by the use of an
open or covered or closed iron vessel, capable of holding any desired quantity of
liquor, which is fixed in a convenient position such as to admit of the ready appli-
cation of constant and steady heat either by gas, fire, or steam.
For the purpose of illustration, say the iron vessel holds 100 gallons.
We place about 50 gallons of clean water in this vessel and add thereto, about
168 lbs. sodic hydrate (Na HO) or potassic hydrate (K HO) and about 56 lbs. of
zinc (Zn), the zinc being first "feathered" by melting and pouring into water or in
some other of the various known methods whereby it is caused to present extended
surfaces and so facilitate its solution. Or galvanised iron cut in convenient sized
pieces may be substituted for the zinc. Heat is gradually applied to the vessel and a
3

page_text: temperature of about 212 degrees Fahrenheit maintained for about 10 hours, or until
the sodic hydrate, or potassic hydrate, depending on the percentage of sodic
oxide (Na 0), or potassic oxide (KO) respectively, which they contain, shall have
dissolved its full proportion of zinc.
When zinc salts are used, ammonic hydrate may be substituted for sodic or potassic
hydrate.
The vessel is then filled up with clean water so that the whole measures 100 gallons.
The heat is withdrawn and the liquor allowed to cool down and settle when the
clear liquor is drawn off, which as already stated, constitutes the zinc solution in
accordance with our invention for application to steam boilers whilst under steam,
but when the solution is required to be used as a wash or paint it may be thickened
by mixing with it Portland cement or lime or other similar substances which will
adhere to the material of the boiler and which in themselves are not corrosive, or the
solution may be evaporated or boiled down to the necessary consistency required.
Dated this 8th day of June 1889.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicants.
COMPLETE SPECIFICATION.
The Manufacture and Application of a Certain Fluid Preparation
for Preventing or Lessening Corrosion and Pitting in Steam
Boilers.
We, JOHN BRADBURNE DODDS, of No. 13 Dean Street, Newcastle-on-Tyne, in the
County of Northumberland, Analytical Chemist, and JOHN REED FOTHERGILL, of
No. 1 Bathgate Terrace, West Hartlepool, in the County of Durham, Superintending
Marine Engineer, 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 statement:-
As is well known corrosion and pitting occur in the interiors of steam boilers, and
various means have been resorted to with the view of obviating the evil. One of these,
which is adopted especially in marine boilers, consists in placing inside the boiler,
either suspended in trays or hangers, or fastened to and in metallic contact with the
metal of the boiler, or applied in some other manner or form, slabs, blocks, or plates
of zinc. These have been found to exercise a beneficial influence to a certain extent,
but are open to the objection that the whole of the zinc required must be placed in the
boiler before closing up and filling the boiler with water; it results that during the
first few days steaming there is a large quantity of zinc very active, then from various
causes (for instance oxidation) the zinc ceases to be effective just when it is required
to act nost efficiently, that is to say, as the source or cause of corrosion becomes more
active which it does the longer the boiler is under continuous steam. Now in order to
obviate this difficulty according to our invention we manufacture zinc solution as herein-
after described, and apply the same to steam boilers at regular or stated intervals, either
with the feed water, by a separate pump, or by injection, or by other similar or suitable
methods, by which means we are enabled to provide and maintain a steady constant and.
effective preventive to corrosion and thereby to preserve the boilers from corrosion.
and pitting. Or the solution may when thickened as hereinafter described be used as
a wash or paint, applied by a brush or in some other convenient and similar manner
to particular corroded or pitted places in the boiler whilst the water is out of the
boiler or to the material of new boilers during construction.
In the manufacture of the zinc solution we add to water suitable quantities of
sodic hydrate (Na HO) or potassic hydrate (K HO) and of zinc (Zn) rendered
sufficiently small to be readily soluble, and we heat the whole until the sodic hydrate
or potassic hydrate, as the case may be, has dissolved its full proportion of zinc after
which more water is added and the whole allowed to cool and settle, and the clear
liquor is drawn off for use according to our invention; or instead of metallic zinc as
described, galvanized iron may be used, cut into convenient sized pieces to facilitate

page_text: the operation. The sodic hydrate, or potassic hydrate as described, will dissolve the
zinc and leave the iron intact; or zinc salts may be used, in which case ammonic
hydrate (H NHO) could be substituted for sodic or potassic hydrate.
In carrying out this invention satisfactory results may be obtained by the use of an
open or covered or closed iron vessel, capable of holding any desired quantity of liquor,
which is fixed in a convenient position such as to admit of the ready application of
constant and steady heat either by gas, fire, or steam. For the purpose of illustration,
say the iron vessel holds 100 gallons. We place about 50 gallons of clean water in
this vessel, and add thereto about 168 lbs. sodic hydrate (Na HO) or potassic
hydrate (K HO) and about 56 lbs. of zinc (Zn), the zine being first "feathered" by
melting and pouring into water, or in some other of the various known methods,.
whereby it is caused to present extended surfaces and so facilitates its solution. Or
galvanised iron cut in convenient sized pieces may be substituted for the zinc.
is gradually applied to the vessel, and a temperature of about 212 degrees Fahrenheit
maintained for about 10 hours, or until the sodic hydrate or potassic hydrate, depending
on the percentage of sodic oxide (Na2O) or potassic oxide (K2O) respectively which
they contain, shall have dissolved its full proportion of zinc.
Heat
When zinc salts are used, ammonic hydrate may be substituted for sodic or potassic
hydrate. The effect of this will be to precipitate hydrated oxide of zinc hereinafter
referred to as the zinc base derived from a zinc salt and which when the mixture is
heated will be dissolved in the ammonic hydrate. The vessel is then filled up with
clean water so that the whole measures 100 gallons. The heat is withdrawn and the
liquor allowed to cool down and settle, when the clear liquor is drawn off, which, as
already stated, constitutes the zinc solution in accordance with our invention for
application to steam boilers whilst under steam; but when the solution is required to
be used as a wash or paint, it may be thickened by mixing with it Portland cement, or
lime, or other similar substances which will adhere to the material of the boiler, and
which in themselves are not corrosive; or the solution may be evaporated or boiled
down to the necessary consistency required.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is
1. The herein described manufacture of zinc solution for use in steam boilers, by
dissolving zinc by the aid of heat, in sodic or potassic hydrate, or by dissolving the
zine base derived from a zinc salt in aminonic hydrate, diluting with water and then
allowing to cool and settle as set forth.
2. The herein described method of applying zinc to steam boilers for preventing or
lessening corrosion and pitting thereof, said method consisting in introducing into the
boiler while the same is under steam and at regular or given intervals, a solution of
zinc prepared substantially in the manner herein set forth.
3. The hereinabove described method of applying zinc to prevent or lessen corrosion
and pitting in steam boilers, which consists in preparing a solution of zinc, thickening
the same by admixture with a suitable substance such as Portland cement or lime, or
concentrating it by evaporation and applying the thickened or concentrated solution
as a wash or paint to the surface to be protected.
JOHN BRADBURNE DODDS.
J. R. FOTHERGILL.
W. Lloyd Wise,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicants.