Improved Means for Promoting Draught in Boiler Furnaces.
Year: 1891

page_text: Date of Application, 23rd Nov., 1891
´omplete Specification Left. 23rd Aug., 1892-Accepted, 24th Sept., 1892
PROVISIONAL SPECIFICATION.
Improved Means for Promoting Draught in Boiler Furnaces.
We, PETER FERGUSON and WILLIAM YOUNG FLEMING both of Phoenix
Engine Works, Paisley, Renfrewshire, Engineers and Shipbuilders, do hereby
declare the nature of this invention to be as follows:-
This invention relates to improved means for promoting draught in boiler
furnaces and it is applicable more especially to marine boilers.
Under one modification of the invention air is supplied to the furnace or furnaces
of the boiler by means of a fan or blower as in ordinary forced draught arrange-
ments but instead of leading the air through casings or similar devices which retard
its flow towards the furnaces we connect the fan or blower direct to a pipe which is
led down through the chimney uptake to the furnace frout the pipe being single
in the case of single flued boilers and single or bifurcated and led down the uptake
in front of the spaces between the fire tubes in the case of double or multiple flued
boilers. The air passing through the pipe or pipes is highly heated in its course
and it is discharged through the furnace fronts valves or dampers being provided
to regulate the admission under or over the fire grate.
In another modification the use of a fan or blower is dispensed with and air is
admitted to the pipe or pipes leading through the uptake to the furnace by an
upward extension of the pipe provided with a trumpet mouth turned towards the
wind or direction of motion of the vessel like an ordinary stoke-hold ventilator. For
use when there may be insufficient air pressure a nozzle is fitted in the air pipe and
connected to a steam pipe or air vessel under pressure so that a jet of steam or air
may be directed down the air pipe to induce draught and promote combustion of the
fuel in the furnace.
Dated this Twenty-first day of November 1891.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.
COMPLETE SPECIFICATION.
Improved Means for Promoting Draught in Boiler Furnaces.
We, PETER FERGUSON and WILLIAM YOUNG FLEMING, both of Phoenix Engine
Works, Paisley, Renfrewshire, Engineers and Shipbuilders, 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:-
This invention relates to improved means for promoting draught in boiler
furnaces and it is applicable more especially to marine boilers.
Under one modification of the invention, air is supplied to the furnace or furnaces
of the boiler by means of a fan or blower as in ordinary forced draught arrange-
ments but instead of leading the air through casings or similar devices which retard
its flow towards the furnaces we connect the fan or blower direct to a pipe which is
led down through the chimney uptake to the furnace front, the pipe being single
in the case of single flued boilers and single or bifurcated and led down the
uptake in front of the spaces between the fire tubes in the case of double or
multiple flued boilers. The air passing through the pipe or pipes is highly heated
in its course and it is discharged through the furnace fronts, valves or dampers
being provided to regulate the admission under or over the fire grate. The fan
may be made to draw from holds & cabins for ventilating purposes.

page_text: In another modification the use of a fan or blower dispensed with and air is
admitted to the pipe or pipes leading through the uptake to the furnace by an
upward extension of the pipe provided with a trumpet mouth turned towards the
wind or direction of motion of the vessel like an ordinary stoke-hold ventilator.
For use when there may be insufficient air pressure a nozzle is fitted in the air pipe
and connected to a steam pipe or air vessel under pressure so that a jet of steam or
air may be directed down the air pipe to induce draught and promote combustion
of the fuel in the furnace.
In the accompanying drawings which illustrate the invention,
Figs. 1 & 2 are front and side elevations of a single furnace boiler; Figs. 3 & 4
of a boiler with two furnaces; Figs. 5 & 6 of a boiler with three furnaces, and
Figs. 7 & 8 of a boiler with four furnaces, in all of which air is supplied to the
furnaces by a fan F which may be made to draw air from the holds, cabins or
engine room of the vessel as may be desired for ventilating purposes. The air is
discharged direct to the furnaces through air pipes a aa which pass through the
uptake in front of the spaces between the fire tubes of the boiler.
Figs. 9 & 10, 11 & 12, 13 & 14, and 15 & 16; show boilers similar to those above
referred to, in which the air is supplied by ventilators V situated on each side of
the funnel and which are capable of being turned in any direction to suit the wind.
The air tubes a a a are led through the uptake in front of the spaces between the
fire tubes of the boiler. A compressed air or steam nozzle S is fitted so as to
direct a jet of steam down the air pipes and induce a draught in case of insufficient
wind pressure.
Figs. 17, 18 are front and side elevations of a double ended boiler having three
.furnaces and showing the application of a fan F for supplying air to the furnaces
in accordance with our invention and
Figures 19 & 20 are similar views of a double ended boiler in which ventilators V
are shown as applied for supplying air to the furnaces.
In the latter example pipes having nozzles S, for leading compressed air or steam
into the air pipes are shown as applied for inducing draught.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is:
1. The employment in conjunction with steam boiler furnaces of a fan or
blower and pipe connections arranged as described for promoting draught in such
⚫furnaces.
2. The employment in conjunction with steam boiler furnaces of ventilators alone
or with the addition of jets of steam or compressed fluid and pipe connections
arranged as described for promoting draught in such furnaces.
Dated this 22nd day of August 1892.
CRUIKSHANK & FAIRWEATHER;
62, St. Vincent Street, Glasgow, Agents.