IMPROVEMENTS IN APPARATUS EMPLOYED IN CONNECTION WITH BLAST FURNACES
Year: 1876

page_text: PROVISIONAL SPECIFICATION left by David George Hoey at the Office of
the Commissioners of Patents on the 24th June 1876.
DAVID GEORGE HOEY, of Workington, in the County of Cumberland, Ironmaster.
"IMPROVEMENTS IN APPARATUS EMPLOYED IN CONNECTION WITH BLAST FURNACES."
My Invention has for its objects providing increased facilities for regulating or
directing the hot blast supplied to blast furnaces, for diminishing the liability of
the apparatus to injury or deterioration from the effects of the hot blast, for
ascertaining when any part of the apparatus is deranged or not in proper working
order, and for effecting necessary repairs without impeding, interrupting, or impairing
the working of the furnace.
In carrying out my Invention in order to effect these objects I provide a main
pipe to encircle or surround the furnace and receive the branch pipes leading from
the different heaters, which pipe is divided into sections by means of valves, which in
the ordinary working of the apparatus remain closed, so that each heater supplies its
own corresponding tuyere. Each of the branch pipes is fitted with a valve near
the heater, and with another valve near the furnace, the encircling main pipe being
situate between these two valves, both of which during the normal working remain
open. When, however, any heater is observed to be even slightly out of order it can
be isolated by closing the valve near to the said heater, whilst by opening one or
more of the valves in the main pipe the blast will continue to pass into the tuyere
without any interruption. The valves arranged in the branch pipes near the furnace
are provided for the following purposes:- When the pipe leading from the main
pipe to any tuyere is out of order it is isolated from the main pipe by closing its
valve, and the supply to the tuyere is continued as before through an auxiliary pipe,
which I attach when required, a suitable flange being provided in the main pipe
opposite each tuyere room for the purpose. When also it is suspected that water
is escaping into the furnace at any tuyere it can be ascertained by closing its valve
and withdrawing the ordinary plug, when a portion of the blast from the other tuyeres
will be ejected through the aperture, and the presence of the least moisture will be
detected. Between each heater and its adjacent valve I place a cock, so that when
a heater has to be reheated after repairs it can be brought up to its normal
temperature with perfect safety by allowing the blast to pass through the heater
and escape through the said cock into the atmosphere, the extent of such escape
being regulated by adjusting the degree of opening of the cock. This cock is 80
constructed as to admit of a pyrometer being applied thereto in order to test the
[Price 2d.]

page_text: temperature of the air and ensure the required degree before the valve is opened for
directing the blast from that heater into the furnace. Where heaters are divided
into two or more compartments, through which the blast is successively conducted,
I fit in connection with each of the compartments a cock of a similar description
and performing a similar function to the cock herein-before referred to so as to
ascertain the degree of heat in each compartment. I further regulate the working
of the several compartments by combining with the use of the ordinary exit valve
or damper employed between the heater and the exit flues a sliding door or valve
at the fire end or entrance, by adjusting the degree of opening of which the heat may
be caused to pass more or less into the different compartments. I also protect the
pipes at the hot end of the heater by means of an air chamber formed between the
said pipes and the ordinary protecting brickwork, through which chamber a current
of cool air (admitted from the external atmosphere is caused to constantly pass,
such current being conducted either by a direct or a circuitous course to the fire
so as to effectually prevent the pipes from being burnt by the heat impinging
directly upon them. In the portion of the main pipe which is situate at the front
of the furnace provision is made for an auxiliary tuyere, which may be used at or
near the level of the other tuyeres, either continuously or as occasion may require,
and either with the full power of the blast or with any lower degree which may be
desired. I also so arrange the apparatus in connection with the auxiliary tuyere
that in the event of the tapping hole becoming obstructed, or of the pot of the
furnace getting deranged in its working, the blast may be directed at any level or
angle in order to melt the obstruction either with or without the use of an external
refinery or small furnace.