IMPROVENENTS IN FURNACES
Year: 1872

page_text: PROVISIONAL SPECIFICATION left by James Barnett and William
Vokins at the Office of the Commissioners of Patents, with their
Petition, on the 16th March 1872.
WC, JAMES BARNETT, of No. 4, Aberfeldy Street, Bromley-by-Bow,
in the County of Middlesex, and William VOKINS, of No. 47, Mark
Lane, in the City of London, do hereby declare the nature of the said
Invention for "IMPROVENENTS IN FURNACES," to be as follows:-
For the purpose of encreasing draught in furnaces & for obviating the
effects of slagging or clinkering upon the fire-bars, we adopt auxiliary
or side fire-bars vertically placed in manner as shown in Diagram 1;
c, c, are the additional bars referred to; d, d, are the air spaces between
these bars, & the sides of the furnace; e, e, are ledges of angle iron resting
upon the top of the bars. The object of these ledges is to intercept the air
travelling up the side spaces, & to compel the currents to pass through
the vertical bar spaces into the fire. To effect this a layer of clay which
has been wetted with a saturated solution of salt must be spread upon

page_text: the ledges, the object of the angles to the iron being to keep this clay in
place. Above this layer we spread another layer of clay in which salt
is not present, or a course of fire-brick may be carried along cemented
with the salted clay. The reason of these two layers is this, under
the action of fire, & in such a position the salted clay might not remain
intact, but require the second layer for its protection. The salted clay is
here used for its non-conducting properties.
In lieu of these vertical bars courses of brick may be carried along
up, built in with the salted clay as a mortar, with the necessary open
spaces for the passage of air into the furnace. To have these side bars
of sufficient strength the width of the furnace becomes reduced; we
therefore lower the bearing bars & compensate for diminished width by
increased depth.
Instead of keeping open the original bars they may be cemented over
with salted clay, & dependance entirely had upon side bars.
Or a
dead plate may be used.
The principle of this Invention consists in the admission of air
through vertical side fire-bars either as auxiliary to or instead of the
ordinary horizontal bars, & the use of alternate salted & plain clay
for the protection of any exposed metal, & for compelling the air
currents to take directions at pleasure into the fire.
We likewise construct a furnace in the manner of a retort, as in
Diagram No. 2, supplying such furnace with air by means of either
a fan or steam blasts, or both conjointly, as at A, B being an outlet
for the passage of the heated air. If a steam blast is used, a fan must
be also used with it to accelerate the passage of the aqueous vapour
through the fire, or a secondary steam blast must be placed in the
chimney else a current of air must run over the fire, which will other-
wise become quenched. The fuel to be used becomes in this furnace
molten, and would therefore of itself reject the passage of air through
its pores; hence to compel the air to penetrate and permeate the mass,
the fire space, with the exception of an outlet for the pussage of the
heated air, must be surrounded with material upon which fire has no
action which it cannot consume. Where the fire is met by water space
this condition of resistance is of course obtained. Where no water
space can be presented its place can be supplied by alternate layers
of salted clay and clay in which salt has not been mixed, as described

page_text: before, and for reasons before stated; or courses of fire-brick cemented
and built in with salted clay may compose those parts of the furnace
where water space cannot be introduced.
When the fire is required to be in action for a period sufficiently
lengthened to make it worth while that the furnace should be per-
manently closed up, such may be done, for so long as the blasts are
continued so long will the fire continue at the highest point of in-
candescence, no waste nor change of any kind whatever occurring, so
that when the fire may for the time be done with, and it is suffered to
go out or is put out) which may be done by turning a steam jet into
it, reducing or discontinuing the means adopted for the due passage of
the aqueous vapour.
Where a fan blast is used which can also be worked by hand, or
where a donkey engine is working a fan, the fire can be lighted against
the tue iron, as on a forge, first with wood & coal, & when perfect
ignition has began the permanent fuel (lumps of clay or other earthy
matter, or ashes wetted with a saturated solution of salt) may be
gradually added until the entire fire space has been filled. This being
done, and the parts of the furnace necessarily left open for the lighting of
the fire built up (with the exception of the outlet for the passage of the
heated current) in the way described before, motive power as permanent
as may be required by circumstances is obtained. The fuel also, as
above described, being subject to no change through the action of fire
can be perpetually re-used.
The principle of this Invention is the construction of furnaces upon
the principle of the retort, air being supplied to the interior by blast, the
sides of the furnace being built of fire-resisting material, leaving the
outlet for the passage of the heated currents of such proportions only as
will prevent the escapement of heat beyond a certain ratio, in the same
manner that the escapement of steam from a boiler at too great a rate
of discharge is provided against for the purpose of checking exhaustion.