Improvements in the Method of Working Iron Blast Furnaces so as to utilise the Gases evolved for Producing Motive Power.
Year: 1896

page_text: Date of Application, 23rd Oct., 1896
Complete Specification Left, 7th July, 1897-Accepted, 7th Aug., 1897
PROVISIONAL SPECIFICATION.
Improvements in the Method of Working Iron Blast Furnaces so as
to utilise the Gases evolved for Producing Motive Power.
We, BENJAMIN HOWARTH THWAITE, of 29 Great George Street, Westminster, in
the County of London, Civil Engineer, and FRANK LACROIX GARDNER, of 32 Old
Jewry, in the City of London, Mining Engineer, do hereby declare the nature of
this invention to be as follows:-
In the Specification No. 15684 of 1896 are described a treatment of the gases
evolved from iron blast furnaces by removing dust, cooling, washing and filtering
them, and the application of the purified gases to the working of an internal
combustion engine for the production of motive power.
Our present invention relates to a method of working the furnaces in such a
manner that a supply of power can be maintained even when it is inconvenient to
smelt iron, that such power can be rendered constant or nearly so, and that, by
heating the hot blast stoves independently of the furnace gases, the whole of these
gases can be utilised for power.
Instead of blowing out a furnace when the state of the markets or other
circumstances lessen the demand for iron, and having to expend time and fuel in
starting it again, it is, according to this invention, kept in action on charges of sand
and limestone so as to produce a fluid slag, which may be available as a substitute
for glass or for making cement or other uses. Even if the slag is useless, the value
of the furnace gases for producing power is sufficient to warrant the continued
working of the furnace as a gas producer, especially when the power is applied to
purposes such as electric lighting, for instance, which require the engine to be kept
at work. In order that the quality of the gases may be ascertained and regulated
whether the furnace be at work in smelting iron or in merely producing slag, a
portion of the purified gases is applied to work a small gas motor engine provided
with a speed indicator, preferably of the recording kind, the speed thus indicated
shewing, by its greater or less degree, the better or worse quality of the gases which
work it, and therefore serving as a guide for regulating blast, fuel supply, and other
conditions on which the quality of the gases more or less depends.
In order not to waste the heat of the gases as they leave the furnace and at the
same time to cool them more or less before purifying them, they are passed through
or among a number of tubes or other extended surfaces among or through which
the air for the furnace blast passes on its way from the blast engine. The heat of
the exhaust gases from the internal combustion engine may also be utilised in
this way.
For cold blast furnaces, the moderate heating of the blast thus obtained is of
advantage as effecting some economy of fuel or improving the action of the furnace.
For hot blast furnaces, where higher temperare of the blast is required, it may
be heated in the ordinary way by alternately acting stoves; but instead of applying
the combustion of the furnace gases to heat those stoves, it is preferred to heat
them by gas produced from fuel of quality much inferior to that required in the

page_text: furnaco, so as to leave all the furnace gases available for motive power. By thus
diverting the furnace gases from the hot blast stoves, not only is fuel economised,
but also the stoves are freed from the objectionable deposit of dust which results
from the use of the furnace gases for heating them. In case the blast furnace
should for any reason cease to work, the gases produced from the coarser fuel for
the purpose of heating the stoves may be diverted through the cleansing and
purifying apparatus to work the engine.
Dated this 23rd day of October 1896.
ABEL & IMRAY,
Agents for the Applicants.
Improvements in the Method of Working Iron Blast Furnaces so as
to utilise the Gases evolved for Producing Motive Power.
WO, BENJAMIN HOWARTH THWAITE, of 29 Great George Street, Westminster, in
the County of London, Civil Engineer and, FRANK LACROIX GARDNER, of 32 Old
Jewry, in the City of London, Mining 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 :--
In the Specification No. 15684 of 1896 are described a treatment of the gases
evolved from iron blast furnaces by removing dust, cooling, washing and filtering
them, and the application of the purified gases to the working of an internal
combustion engine for the production of motive power.
Our present invention relates to a method of working the furnaces in such a
manner that a supply of power can be maintained even when it is inconvenient to
smelt iron, that such power can be rendered constant or nearly so, and that, by
heating the hot blast stoves independently of the furnaco gases, the whole of these
gases can be utilised for power.
Instead of blowing out a furnace when the state of the markets or other
circumstances lessen the demand for iron, and having to expend time and fuel in
starting it again, it is, according to our invention, kept in action on charges of fuel
sand and limestone so as to produce a fluid slag, which may be available as a
substitute for glass or for making coment or other uses. Even if the slag is useless,
the value of the furnace gases for producing power is sufficient to warrant the
continued working of tho furnace as a gas producer, especially when the power is
applied to purposes such as electric lighting for instance, which require the engine
to be kept at work. In order that the quality of the gases may be ascertained and
regulated whether the furnace be at work in smolting iron or in merely producing
slag, a portion of the purified gases is applied to work a small gas motor engine
provided with a speed indicator, preferably of the recording kind, the speed thus
indicated shewing, by its greater or less degree, the better or worse quality of the
gases which work it, and therefore serving as a guide for regulating blast, fuel
supply, and other conditions on which the quality of the gases more or less depends.
In order not to waste the heat of the gasos as they loave the furnace and at the
same time to coo! them more or less before purifying them, they are passed through
or among a number of tubes or other extended surfaces among or through which
the air for the furnace blast passes on its way from the blast engine. The heat of
exhaust gases from the internal combustion engine may also be utilised in this way.
For cold blast furnaces, the moderate heating of the blast thus obtained is of
advantage as effecting some economy of fuel or improving the action of the furnace.

page_text: For hot blast furnaces, where higher temporature of the blast is required, it may
be heated in the ordinary way by alternately acting stoves; but instead of applying
the combustion of the furnace gases to heat these stoves, it is preferred to heat them
by gas produced from fuel of quality much inforior to that required in the furnace,
so as to leave all the furnace gases available for motive power. By thus diverting
the furnace gases from the hot blast stoves, not only is fuel economised, but also
the stoves are freed from the objectionable deposit of dust which results from the
use of the furnace gases for heating them.
In case the blast furnace should for any reason cease to work, the gases
produced from the coarser fuel for the purpose of heating the stoves may be
diverted through the cleansing and purifying apparatus to work the engine.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The herein described method of working a blast furnace as a gas producer by
charging it with fuel sand and limestone when no iron has to be smelted.
2. The herein described method of cooling the furnace gases and heating the air
for the furnace blast by causing the gases to pass from the furnace through or
among tubes or other extended surfaces while the air passes among or through them
on its way to the furnace or stove.
3. The herein described method of heating stoves for hot blast by the combustion
of producer gas obtained from inferior fuel, so that the furnace gases are all available
for production of motive power.
4. The herein described method of testing and recording the working of a blast
furnace by the speed register of a gas motor engine worked by the waste gases of
the furnace.
Dated 1 1 1 1 1 1007
ABEL & IMRAY,
Agents for the Applicants.