Improvements in Furnaces Working with Forced Draught.
Year: 1890

page_text: Date of Application, 21st Jan., 1890
Complete Specification Left, 21st Oct., 1890-Accepted, 17th Jan., 1891
PROVISIONAL SPECIFICATION.
Improvements in Furnaces Working with Forced Draught.
I, HUGH CHRISTIE PATERSON of 17 Camden Gardens Uxbridge Road in the County
of Middlesex Engineer do hereby declare the nature of this invention to be as
follows:-
The object of my invention is to overcome the objections applying to furnaces
worked with forced draught as at present constructed due to the necessity of making
the whole of the ash pit tight and the impossibility of properly guiding or directing
the air as required.
According to my invention instead of admitting the forced draught into the whole body
of the ash pit, I provide in the ash pit pipes or channels perforated on the side presented
towards the fire bars. These pipes or channels I connect with the air forcing device
by which air is forced into these tubes or channels and out by the perforations and
thence through the fire bars to the fire.
The fire bars may be formed in cross section so that they are presented towards the
perforated pipes or channels in a direction best calculated to receive their due supply
of air.
In order to regulate the draught supply I may provide in connection with the air
supply tubes or channels a valve or valves opening to the outer air by adjusting which
I can supplement the forced draught as required.
Although I have mentioned air it is to be understood that I may use instead of air
or in addition thereto steam or other fluid or gas suited to be used in connection with
the forced draught.
The pipes or channels may be in any desired number and may be extended through
any desired portion of the ash pit and in some cases they may be carried to or beyond
the bridge or other part of the furnace whose heating effect it may be desirable to
obtain for heating the blast.
Datad this 01st day of January 1890.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, Agents.
COMPLETE SPECIFICATION.
Improvements in Furnaces Working with Forced Draught.
I HUGH CHRISTIE PATERSON of 15 Camden Gardens Uxbridge Road in the County
of Middlesex 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 object of my invention is to overcome the objections applying to furnaces
worked with forced draught as at present constructed due to the necessity of making
the whole of the ash pit air tight and the impossibility of properly guiding or
directing the air as required.
According to my invention instead of admitting the forced draught into the whole
body of the ash pit, I provide in the ash pit a pipe or channel or pipes or channels
perforated on the side presented towards the fire bars. These pipes or channels I
connect with the air forcing device by which air is forced into the tubes or channels
and out by the perforations and thence through the fire bars to the fire.
The accompanying drawing represents an arrangement illustrative of my invention,
Figure 1 being a longitudinal section and Figure 2 a transverse section on the
line 1-2 Figure 1.

page_text: at a.
I have here shewn two pipes or channels A situated closely against the side of the
ash pit and connected together at the rear by a pipe A². Their top sides are perforated
The end of each pipe or channel may be provided with a door b for cleaning or
other purpose.
Into each such pipe or channel a tube C opens the air being forced
into these tubes C and thence into the pipes or channels A and out by the openings a.
The fire bars D may be formed in cross section as shewn at d Figure 2 or they may
be constructed in the ordinary way and carried on concave hearers so that they are
presented towards the perforated pipes or channels A in a direction best calculated to
receive their due supply of air.
In order to regulate the draught supply I may provide in connection with the air
supply tubes or channels A a valve or valves opening to the outer air by adjusting
which I can regulate the forced draught as required. In this case the air blast pipe (
should terminate in the perforated air supply tubes or channels A in a nozzle a¹ with
the valve for the admission of outer air situated at its rear as shewn at a².
Although I have mentioned air it is to be understood that I may use instead of air
or in addition thereto steam or other fluid or gas suited to be used in connection with
the forced draught.
The pipes or channels A may be in any desired shape number or position and may
be extended through any desired portion of the ash pit and they may be carried only
partly through the ash pit or to or beyond the bridge or other part of the furnace
whose heating effect it may be desirable to obtain for heating the blast.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
First. In furnaces worked by forced draught a perforated pipe or channel or
perforated pipes or channels situated in the ash pit or under the fire bars and provided
with means for forcing air steam or gas thereinto and therefrom substantially as
herein before described.
Second. In furnaces worked by forced draught a perforated pipe or channel or
perforated pipes or channels situated in the ash pit or under the fire bars and provided
with means for forcing air steam or gas thereinto and therefrom in combination with
fire bars inclined towards the pipe or channel or pipes or channels substantially as and
for the purpose hereinbefore described.
Dated this 21st day of October 1900.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, Agents.