Year: 1888

page_text: A communication from abroad by WILLIAM TWINING WELLS, of Hackensack, Bergen
County, State of New Jersey, United States of America, Manufacturer.
I, WILLIAM PHILLIPS THOMPSON F.C.S. M.I.M.E. of the Agency for Foreign
Patent Solicitors, 6 Lord Street, Liverpool, and 6 Bank Street, Manchester, both in
the County of Lancaster, and 323 High Holborn, in the County of Middlesex, Civil
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:―
The invention relates to the protection of iron and steel surfaces by the production
of a rustless coating thereon, and has for its object the more economical, reliable,
and effectual production of such a coating than is possible by any process heretofore
devised, and it consists of the improved process and apparatus herein described and
claimed.
This new process for the production of a rustless coating upon iron or steel is
devised and adapted to economically and reliably produce such coating in an even
and impenetrable layer all over the surfaces of the charge and every part thereof,
and to be equally effective in its application to large and to small charges, and in
ordinary furnaces, avoiding at once the expensive retorts and special muffles of the
old process, and the blistering and over oxidizing incident to these processes as well
as their general irregularity of result.
In practicing the invention the charge, which may be of any size, is placed in an
ordinary muffle or heating chamber, and the charge is heated up gradually and
thoroughly through several hours in any desired way, and it is preferably cleansed
and otherwise prepared as hereinafter described. Into said heating chamber is then
injected a mixture of steam and carbon monoxide so that the atmosphere in contact
with the heated charge shall, as far as practicable, consist of steam and carbon
monoxide. The chimney damper or dampers of said heating chamber are then
closed, and the mixture and carbon monoxide left to act upon the heated charge for
several hours, varying with the size of the charge etcetera, generally about five hours,
taking pains to permit the escape of the hydrogen generated thereby. The charge,
when allowed to cool, will be found to be of a uniform color all over its surfaces
wherever the mixture of steam and carbon monoxide has been in contact with it in
its heated condition, and the coating will be found to be an even and impenetrable and
CO

page_text: J
continuous coating of rustless oxide of iron. The chemical operations that proceed
in this new process, so far as they are at present understood by my correspondent,
seem to be as follows:-The mixture of steam and carbon monoxide in contact with
the heated surface of the iron or steel oxidizes the metallic iron, and the lower oxides,
raising all to the rustless oxide, and it simultaneously reduces the higher. oxides to
the same uniform rustless oxide; and the mixture also partially scales off, or otherwise
removes the higher or red oxide, in the shape of a fine red dust of oxide of iron,
which is generally found settled on the drag or charging plate of the heating chamber,
the unitary effect being to produce over the previously heterogeneous surfaces of the
iron or steel, a homogeneous layer or coating of rustless oxide, even and continuous
over the entire surfaces of the iron or steel, and integral with the mass of the metal.
In this operation, the steam of the mixture appears to be the active agent in
producing the oxidizing results; but in such operation it is limited and controlled by
the presence and action of the carbon monoxide of the mixture. In the general
operation also, the carbon monoxide appears to be the active agent producing the
deoxidizing effects, but in such operations it is limited and controlled by the presence
and action of the steam. The carbon monoxide also appears to operate to burn up
or consume the free oxygen of the steam, and the oxygen of the air, that may leak
into the chamber during the progress of the operation-a leakage which is unavoidable
in practice, which air with its free oxygen would otherwise attack the heated iron of
the charge, and raise it in spots to a red oxide. The elements of the charge in contact
with each other and operating together, and operating under much heat, work
together to produce the unitary result described. The simultaneous and conjoint
operation of the steam and the carbon monoxide in contact with the heated surface of
the iron or steel charge, whatever the previous condition of the surface, offects the
complete conversion of that surface into the black or magnetic oxide and to a depth,
and with a character continuous, tenacious, and integral with the internal mass or body
of the iron or steel, which causes it to form an impenetrable rustless coating, and
to act as a complete protection of the entire mass or charge from injury by rust..
The best method which my correspondent has discovered of carrying out the
invention is as follows: it being understood that the various steps which he now
describes as preceding the process heretofore described, are preparatory steps preferred
to be carried out by him in embodying his invention, and tending to perfect the
ultimate result produced, but to which he does not wish his broad invention to be
limited.
The charge of iron or steel articles of say 12000 pounds weight is first placed in an
ordinary muffle or heating chamber, and there the charge is heated up gradually
through a period of twelve hours more or less, varying with the size of the charge
etcetera. It is important not to heat any part of the charge so hot as to blister it, and
yet every part of the charge must be raised to the dull red heat required. It is
preferable to use the gas made by the well known Siemens' producer for the purpose
of thus gradually heating the charge, and to admit air in limited quantities into the
chamber along with the gas coming from the producer, just enough to consume the
latter, and to give a small flame in the chamber. During this operation the dampers
will be open, permitting escape of the products of combustion to the chimney. The
heating should be gradual whereby blistering of the parts of the charge will be
avoided; and whereby the whole charge will be evenly and equally heated; and should
be so controlled that the charge will reach its maximum of heat at about the end
of twelve hours. For a smaller charge a shorter period of time is required. The
surface of the charge may be, by this particular method of gradual heating, somewhat
oxidized, both to a red and a black oxide, but the effect is irregular and patchy where
it does appear at all, and is not of any importance in our general process.
At the end of the heating step of the process the gas from the Siemens' producer
is turned off and also the air, and steam is introduced into the hot chamber containing
the heated charge, and after the steam has blown the remnants of the gas out of the
chamber, the dampers of the same are closed, and the steam left turned on for some
Ithirty minutes or thereabout. This is merely a cleaning step, the steam operating to

page_text: clean the surface of the charge and free it from scale and foreign substance, and
thereby prepare it for the steps of the process that follow. The charge is very hot
during this cleaning step, and the steam seems to operate the scale off and remove
mechanically or otherwise, a part of the red oxide from the surface of the charge; if
any be present.
At the completion of this cleaning step of the process, the steam from the chamber
is turned off, and carbon monoxide is introduced, and when the atmosphere of the
chamber is cleared of the steam thereby, the dampers are closed again and the charge
submitted in its very hot condition to the action of the carbon monoxide alone, for an
hour and a half, more or less. The operation of the carbon monoxide is to partly
remove the red oxide or sesqui-oxide of iron that may have existed upon the surface of
the charge, or been produced thereon by the earlier steps of the process, leaving in
its place, magnetic oxide or lower oxides, or even metallic iron, these black parts of
the surface being intermixed with irregular patches of red oxide, but of fine microscopic
texture, and all substantially integral with the body or mass of the metal charge, the
rough and scaly separable portions of the oxide on the surface having disappeared as
the result of the last two above described steps of the process.
.
The charge is now prepared in the best manner known to my correspondent for the
final and essential step of the process. The steam is now turned on and the carbon
monoxide left turned on, and the chimney dampers of the chamber closed, and for
five hours, more or less the charge is submitted to the operation of the mingled steam
and carbon monoxide as heretofore described. The heat of the charge at the beginning
of the operation should be a dull red heat, and air should be excluded as far as prac-
ticable. The steam need be under little or no pressure, and may or may not be super-
heated before being introduced into the chamber.
This last or fourth step is the essential step of the process, and is the one in which
is produced the effective rustless coating of black or magnetic oxide that is sought.
The first three or preparatory steps described above, conduce to the ultimate production
of a more perfect and homogeneous protective coating, and may be employed one or
all of them in conjunction with the final step of the process as described; or that
single and essential step may be employed alone.
The accompanying drawings, forming part of this specification to which reference
will now be made, represent the furnace used in carrying out this improved process.
Figure 1 is a vertical longitudinal section on the line f, f, Figures 3 and 5.
Figure 2 is a vertical longitudinal section on the line g g, Figure 5.
Figure 3 is a horizontal section on the line e e, Figures 1 and 2.
Figure 4 is a horizontal section on the line bb, Figures 1 and 2.
Figure 5 is a transverse vertical section on the line d d, Figure 2.
Figure 6 is a transverse vertical section on c c, Figure 2.
The respective parts are shown in the several figures as follows, the same letters
representing the same parts; V is a gas valve; A is an air valve; G is a gas flue;
His a steam valve; C is a combustion chamber; O is an opening into the port
chamber; 1, is a port chamber; h, h, h, are port holes, T is a heating chamber; E is
the escape flue; D is the chimney damper; F is the chimney flue; P is a checker
work in the combustion chamber; 8, 8, 8, are sight holes in the back of the heating
chamber; L L are curtains of masonry.
When the articles are to be treated for the production of a rustless oxide upon
their surface, they are placed in the heating chamber T by being drawn in upon a
drag through the doors B. The charge is then heated up gradually and thoroughly
through a period of from ten to twelve hours, varying with the size of the charge,
and preferably by the admission of gas from a Siemens' producer, admitted through
the gas flue G by opening the valve V, a small quantity of air being admitted for the
purpose of combustion by opening the valve A, during which operation the damper D
is open, permitting escape of the products of combustion to the chimney. The gas
entering through V commingles with the air passing through A at the extremity of
the curtain L, and is aided in its commingling by the checker work P in the com-
bustion chamber; and the burning gas passing through O enters the port chamber I

page_text: from which, through the port holes it passes up, around, through and over the
charge in T and thence through the port holes h into the escape Blue E to the
chimney flue F. When the charge has been sufficiently heated so as to show through
the sight holes a dull red heat, the valves V and A are closed, and steam from any
convenient generator is admitted through the valve H, and after the remnants of the
gas have been displaced from the chamber, the damper D is closed and the steam is
forced in for a period of thirty minutes or thereabouts. This step is found to clean
the surface and prepare it for the steps that follow. The valve H is then closed, the
damper D and the valve V opened, and when the atmosphere of the chamber is
cleared of the steam, the damper D is closed and the charge submitted to the action
of the gas free from air, for upwards of an hour and a half. The valve H is now
opened and for five hours or thereabouts, the charge submitted to the operation of the
mingled steam and carbon monoxide, excluding the air as far as practicable.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
1. The process substantially as described of protecting iron and steel articles from
rust, which consists in subjecting such articles at a high temperature, to the action
of mingled steam and carbon monoxide.
2. The process, substantially as described, of protecting iron and steel articles from
rust, which consists in gradually heating such articles and subjecting them at a high
temperature, to the action of mingled steam and carbon monoxide.
3. The process, substantially as described, of protecting iron and steel articles from
rust, which consists in subjecting such articles, at a high temperature, to the action
of steam, then subjecting them to the action of carbon monoxide and then subjecting
them to the action of mingled steam and carbon monoxide.
4. In the process of protecting iron and steel articles from rust, the gradual
heating of such articles to a high temperature, and subjecting them at such high
temperature to the action of steam, whereby the rough parts of the surface are
scaled off or removed, and the surface is cleansed, substantially as described
and shown.
5. The process, substantially as described, of protecting iron and steel articles from
rust, which consists in gradually heating such articles, then subjecting them at a high
temperature to the action of steam, then subjecting them to the action of carbon
monoxide, and then subjecting them to the action of mingled steam and carbon
monoxide.
6. The process, substantially as described, of protecting iron and steel articles
from rust, which consists in gradually heating such articles by consuming in the
heating chamber the gas made by a Siemens' producer, then subjecting them at a
bigh temperature to the action of steam, then subjecting them to the action of
carbon monoxide, and then subjecting them to the action of mingled steam and
carbon monoxide.
7. In combination, the combustion chamber C, provided with curtains L L and
checker work P, the air valve A, gas valve V, the port chamber I, the heating
chamber D, and the escape flue E, substantially as shown and described.
8. In combination, the combustion chamber C provided with curtains L L and
checker work P, the air valve A, gas valve V, and steam valve H, the port chamber 1,
- the heating chamber D, and the escape flue E, substantially as shown and described.
Dated this Seventh day of May 1888.
WM. P. THOMPSON & Co.,
Agents for the Applicant.