Improvements in Protecting Devices for Furnaces.
Year: 1899

page_text: Date of Application, 16th June, 1899.
Complete Specification Left, 15th Mar., 1900-Accepted, 21st Apr.. 1900
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[Communicated from abroad by JOHN SIMON UNGER, of Homestead, in the County
of Allegheny, State of Pennsylvania, one of the United States of America,
Chemist.]
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Improvements in Protecting Devices for Furnaces.
1
I, WILLIAM BURGELAND JOHNSON, of 4, Clayton Square, Liverpool, in. the
County of Lancaster, Engineer, do hereby declare the nature of this invention.
to be as follows:-
The object of my invention is to provide means for protecting metal parts of
furnaces which are exposed to great heat. I have specially designed the inven-
tion for the protection of the gas supply pipe... by which hydro-carbon gas is
delivered to the space between armour plates or like masses, of steel while under-
going the gas carburization process in a heating furnace: The cutting, action of.
the intensely hot gases in such furnace is very destructive to the gas supply
pipes, and the various expedients which have been tried heretoforé for the pro-
tection of such pipes, such as the use of water jackets and asbestos, wrappings,
have not proved satisfactory.
r
f
My invention consists in applying to the surface to be protected a, jacket of
carbon which, by furnishing carbon to combine with and neutralize, all oxidizing
gases which may penetrate to the metal surface, affords a complete, protection.
The mode in which I prefer to apply the invention to practice in protecting a gas.
supply pipe is to place around the gas supply pipe an outer pipe or sheath and
fill the intermediate space with bituminous coal or like coking, material, so that
when heated it will be converted in situ into a jacket of coke, which as. it swells
somewhat in coking will make a very tightly fitting cover for, the pipe. When
the pipe so arranged is in the furnace, the intense heat of the latter will soon
coke the coal, driving off the volatile gases which escape at the ends of the sheath-
ing, leaving in the sheathing a closely fitting jacket of carbon. which will prevent;
access to the pipe of any oxidizing gases... Apipe..thus protected will, be found
at. the end of a run of the furnace. to be. quite, unburned, and, although the,
exterior sheathing. may be, oxidized, this, is a matter of but little moment as it.
may be made of cheap material and is therefore easy to replace:
For the purpose of cleaning the interior of the gas supply pipe from the carbon
which is deposited therein by decomposition by the hydrocarbon gas I may pro-,
vide at its rear end a removable plug, on removing which a cleaning rod may:
be pushed through the pipe.
It will be understood that modifications of my invention; in order to adapt it to.
other parts or places of a furnace structure, may be easily made without depart
ing from the nature of the invention.
6'2
T
1000-

page_text: Improvements in Protecting Devices for Furnaces.
I, WILLIAM BURGELAND JOHNSON, of 4, Clayton Square, Liverpool, in the
County of Lancaster, 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 reference being had to the
accompanying drawing:-
-
The object of my invention is to provide means for protecting metal parts of
furnaces, which are exposed to great heat. I have specially designed the inven-
tion for the protection of the gas supply pipe, by which hydrocarbon gas is
delivered to the space between armor plates or like masses of steel while under-
going the gas carburization process in a heating furnace. The cutting action of
the intensely hot gases in such furnace is very destructive to the gas supply
pipes, and the various expedients which have been tried heretofore for the
pro-
tection of such pipes, such as the use of water-jackets and asbestos wrappings,
have not proved satisfactory.
My invention consists in applying to the surface to be protected a jacket of
carbon which, by furnishing carbon to combine with and neutralize all oxidizing
gases which may penetrate to the metal surface, affords a complete protection.
The mode in which I prefer to apply the invention to practice, and which I claim
herein specifically, is to place around the gas supply pipe an outer pipe or sheath,
and fill the intermediate space with bituminous coal or like coking material, so
that when heated it will be converted in situ into a jacket of coke which as it
swells somewhat in coking will make a very tightly fitting cover for the pipe.
In the drawing which is a vertical section of a furnace provided with my
improvement, 2 represents a heating furnace of the usual construction, 3, 3 are
armor plates, supported on a hearth 4, and separated by supporting blocks or
billets 5, so as to afford an intermediate space 6, into which the carburizing
hydro-carbon gas is delivered from a pipe 7. Around the pipe 7, I place an outer
pipe or sheathing 8, of larger diameter and I fill the space between the pipes with
a body of bituminous coal 9. When the pipe so arranged is in the furnace, the
intense heat of the latter will soon coke the coal, driving off the volatile gases
which escape at the ends of the sheathing, and leave in the sheathing a closely
fitting jacket of carbon which will prevent access to the pipe of any oxidizing
gases. A pipe thus protected will be found at the end of a run of the furnace
to be quite unburned, and, although the exterior sheathing 8 may be oxidized,
this is a matter of but little moment as it may be made of cheap material and.
is therefore easy to replace.
For the purpose of cleaning the interior of the gas supply pipe from the
carbon, which is deposited therein by decomposition of the hydro-carbon gas, I
provide at its rear end a removable plug 10, on removing which-a-cleaning-rod-
may be pushed through the-pipe.
It will be obvious that modifications of my invention. in order to adapt it to
other parts or places of a furnace structure may be easily made by those skilled
in the art, without departing from the nature of the invention.
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) As a protecting device for metal parts exposed to hot gases in furnaces, the
combination with the metal part of a sheath and a jacket of carbonaceous motorial

page_text: interposed between the part to be protected and the sheath, and adapted to
be coked in situ substantially as described.
(2) As a protecting device for metal parts exposed to hot gases in furnaces, the.
combination with the metal part of a sheath and a jacket of coal interposed
between the part to be protected and the sheath, and adapted to be coked in situ,
substantially as described.
Th
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