Improvements in or relating to Furnaces.
Year: 1890

page_text: Date of Application, 12th Dec., 1690-Accepted, 17th Jan., 1891
COMPLETE SPECIFICATION.
Improvements in or relating to Furnaces.
We, JOHN OLDROYD, and JOHN WILLIAM OLDROYD, Engineer, of Grunberg in the
German Empire do hereby declare the nature of my invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement :-
My present invention relates to that system of heating boilers and other furnaces,
described in the Specification of my Letters Patent No. 2612" and constitutes a
further improvement in this said system.
In the Specification aforesaid, I have described and claimed a method of separating
the combustion gases, and causing those imperfectly consumed to flow through a
tubular system in the steam space of the boiler for superheating purposes back into
the fire box, underneath the grate.
In my present system, hereinafter described and illustrated in the accompanying
drawings, I no longer separate the combustion gases, but canse them, unseparated to
pass into a mixing chamber, where they are mixed with a certain quantity of previously
heated fresh air and then returned through both water and steam space of the boiler―
and not as heretofore simply through the steam space-and then passed into the fire
box underneath the grate. By this means I superheat the steam, warm the water and
attain a perfect combustion; resulting in great economy in fuel and avoiding the
unpleasant and injurious effects caused by the escape of the products of imperfect,
combustion. As the water will by using my system be kept in continuous inotion
the formation of incrustations is to a great extent prevented.
In the accompanying drawings
Fig. 1. is a partial vertical section showing the arrangement of my furnace in
connection with a Cornwall boiler;
Fig. 2 is a sectional plan of the same;
Fig. 3 shows a part elevation and part section of the front end of the boiler :
Fig. 4 is a cross section on line xx, Fig. 1;
Fig. 5 is a cross section on line y y. Fig. 1.
The boiler A has two flues B and B running through it, in which the furnaces
are arranged, and can be bricked in, in the usual manner, so as to have two side
Anes D D which lead into the lower central flue E communicating with the chimney.
The end chambers F F¹ connecting the flues B B and D D¹ respectively, are
separated from one another by the partition C, and in these chambers are arranged
pipes a a¹ on one side and e e¹ on the other, said pipes being provided with funnel
shaped mouths. The pipes a a¹ run longitudinally through the boiler under the water
line, are bent round at the further end and return on the opposite side opening finally
into the mixing chamber S. The hot air pipe e also extends through the boiler under
the water line, returning and opening into the chamber S. The hot air pipe e¹ how-
ever runs longitudinally through the steam space of the boilers above the water line,
extending, through the boiler and back again and opening likewise into the chamber S.
The hot gases circulating through this pipe el are employed to superheat the steam.
The mixing chamber S is connected with the ventilator V and further with two air
pipes m n into which the air is drawn at m¹ n' at the back of the boiler or elsewhere.
These air pipes are preferably arranged in the side flues D D and in the bottom
entral flue E, so that the air in passing along the same will be warmed, previous to
entering the mixing chamber. The position of these tubes may be clearly seen from
Fig. 3 and 4.
When set in motion the ventilator will thus draw into the mixing chamber S a part
of the combustion gases, which have been cooled down to a certain extent, and also
a certain quantity of fresh air, previously well heated. In this chamber S a thorough
D
C

page_text: mixing of the air and combustion gases takes place, which mixture is then forced by
the ventilator along the pipe system into the perforated pipe g extending underneath
the grate; here it is driven through the perforations g' by which it is finely divided
in order to attain a complete combustion, in passing from below through the fire bars
and burning fuel.
By means of the tubular system hereinbefore described and the manner of circulating
the combustion gases and hot air therein, I attain
1) An advantageous heating of the water in the boiler,
2) The superheating of the steam,
3) Great economy in fuel and finally,
4) An entirely smokeless firing.
It is obvious that I can adapt my system to other than Cornwall boilers.
Having now particularly described and ascertained the nature of my said inven-
tion and the manner in which the same is to be performed what I claim is :
In furnaces
1) The method of forcing the combustion gases, back through the boiler not only
through the steam space but also through the water space in the manner and for the
purpose, substantially as described.
2) The method of mixing the combustion gases with air previously heated as
specified and forcing the mixture under the grate for recombustion in the manner and
for the purpose, substantially as described.
3) The method of and apparatus for constructing a boiler furnace, substantially as
hereinbefore described and shown.
4) My improved system of air and smoke flues and tubes, substantially as described
and shown.
Dated this 12th day of December 1890.
W. P. THOMPSON & BOULT,
Agents for the Applicants.