Year: 1887

page_text: I, LORENZO MONDINI of No. 4 Via Balbi, Genoa, Italy, Engineer, do hereby declare
the nature of my said invention and in what manner the same is to be performed
to be particularly described and ascertained in and by the following statement :-
My invention relates to a double ash pit for boiler furnaces.
All studies and experiments for the purpose of attaining the greatest possible degree
of heat in steam boiler furnaces have not succeeded in attaining a perfect combustion
of the fuel. In the furnaces at present in use, the disadvantage appears that a large
part of the fuel is converted into slag and smoke without having produced sufficient
heat. A further disadvantage is that the consumption at the rear part of the con-
sumption space is much less perfect and consequently the formation of slag much
greater than in the foremost part.
The reason is found therein, that the air has been deprived of its oxygen by the fire
in the forward part of the furnace, before it reaches the rear part of the same and
consequently has not the power to keep up the fire, id. est. to produce a perfect com-
bustion. By means of iny double ash pit I obtain a perfect and entirely regular
consumption of the fuel, not only in the forward, but also in the rear portion of the
consumption chamber.
Figure 1 represents the longitudinal section of a boiler furnace. Figure 2 a
horizontal section on the line a-b. Figure 3 is an end elevation partly in section,
Figure 4 the end view of a furnace with my double ash pit.
Now according to my invention I divide the ash pit into two parts by means of a
plate A, so that a fresh powerful draught is produced, not only in the forward, but
also in the rear part of the grate and consumption chamber.
This plate, which can be of straight, curved or other appropriate form, reaches
outwards beyond the brickwork in order to facilitate the removal of the ashes and
inwards up to about the middle of the length of the grate and is furthermore inclined
downwards towards its outer end, that is, the end protruding from the brickwork is
lower than the end within the ash pit.

page_text: As aforementioned this Plate A divides the ash pit into two parts, the upper B and
the lower C; the direction of the air feed on its way to the consumption chamber D
being shown by the arrows in Figure 1.
In order to still further assure the attainment of the object in view, I also feed steam
from the boiler by means of steam pipes E into the upper and lower parts of the ash
pit, suitable cocks or valves being so arranged in the said steam pipes, that tho influx
of steam can be regulated. The pipes E can be fed with live or with exhaust steam
so that the powerful steam influx to the ash pit causes the necessary air for the perfect
consumption of the fuel to be drawn in with great energy and in this manner the fire
bars are much better preserved than is the case at present. It will be evident that
with large ash pits two or more such plates A can be employed, so that the ash pit is
divided into more than two parts and the steam be led between the said plates as may
be requisite. By means of the improved ash pit a much better consumption of the
fuel and consequently a considerable saving in the same is attained and the formation
of slag is reduced to a minimum. The plate A can be made of appropriate metal or
refractory material and experiments have proved that plates which are a few centi-
meters shorter than half the length of the grate, give the best results. It is evident
that my improved ash pit can be employed not only in steam boiler furnaces but for
furnaces of all kind.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is
1. In furnaces the use of one or more plates in the ash pit so as to divide the said
ash pit into two or more parts, substantially as and for the purpose sot forth in the
foregoing specification and shown in the accompanying drawing.
2. The use of one or more tubes or pipes E for leading steam into the ash pit in
combination with one or more plates A, substantially as and for the purpose set forth
in the foregoing specification and shown in the accompanying drawings.
Dated this 24th day of December 1887.
Dated this 24th day of December 1887.
L. MONDINI.
Per W. H. Beck,
115, Cannon Street, London, E.C.,
Agent.