Improvements in Boiler Flues.
Year: 1891

page_text: Date of Application, 3rd Oct., 1891-Accepted, 7th Nov.. 1891
Improvements in Boiler Flues.
I, FRANZ LOUIS OSCHATZ of Meerane, in the Kingdom of Saxony, German
Empire 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 :-
My said invention relates to a new method of and means for preventing a deposit
of ashes in boiler flues.
In carrying out my invention, I divide the air current into two or more parts
and allow these several parts afterwards to reunite. By this means a greatly
improved effect is attained, and also the smoke is brought into perfect combustion.
The effect of this is to minimise the amount of soot in the flues, and the latter will
therefore offer less resistance to the passage of the blasts, which will thus advance
with great rapidity, sweeping away all particles of ashes.
The above method is illustrated in the accompanying sheet of drawings, in which
similar letters of reference indicate corresponding parts.
Figure 1 shows the arrangement, which I consider most effective.
Figure 2 is an end view of the first showing the flue in cross section.
Figures 3, 4, 5 and 6 are modifications.
The device shown in Figure 1 consists of a plate a of iron or other metal or
material bent to an angle. Close to the bottom of said plate a passage or orifice
is left, and a smaller horizontal aperture c is cut out of the centre. At the upper end
of the plate there is a narrow slit e between said plate and the side of the flue.
The central opening c is placed at the bond of the angular plate a, and behind it
there is a second plate for the purpose of guiding the air blasts which pass
through the aperture c to the lower part of the flue. The blast is thus divided into
three currents of which the main stream passes along the bottom of the flue; the
second flows through the central opening, and the third through the narrow slit e
at the top. The strongest blast passes through the bottom of the flue, and so
prevents the collecting of ashes, while at the same time the top of the flue to which
only small quantities of ashes will adhere, is brushed by a much weaker blast. The
middle current is conducted downwards by the plate, and meets the lowest blast
which first passes through the opening at b. In this way the mixing is made very
complete, and since the particles of soot come in very close contact with the hot
blasts a complete combustion of the former takes place.
If so desired, there may be two or more of the above described device in the
flue, arranged one behind the other.
Figure 3 shows a modified arrangement in which the plate is not bent but is
divided into two distinct portions a a', and also the opening c is made larger.
Behind the opening c is placed another plate, parallel with the plates a, a¹. The
plates are so arranged that the opening leading downwards is larger than that
leading upwards, thus causing the main current to flow downwards through the
bottom of the flue. In this way, when the mixture with the gases takes place, a
thorough combustion of the smoke results, and at the same time the blast sweeps
away with great violence all ashes which might in other cases adhere to the walls.
In the modifications shown in Figures 4 and 5, the front plate is arranged in a
similar manner to that shown in Figure 1, while the hinder plate f is made in a bent
form as shown conducting the blasts either in the direction previously indicated in
Figure 1 or in those shown in Figure 3.
In the arrangement shown in Fig. 6 there are three plates, so arranged that the
central opening c extends nearly across the flue being divided by the plate f. The

page_text: apertures be are left on each side as before described with reference to Figure 3.
In this case it is evident that the result will be the same as before.
Other modifications may be employed, without departing from the main features
or object of my invention."
For the purposes of cleaning, the lower portions of the plates may be hinged to
the upper parts, so as to admit of free access to all parts, without having to entirely
remove the plates.
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 :
The combination in a boiler flue of a blast guiding plate or plates with a central
opening and another plate arranged either behind or within said opening,
substantially as, and for the purposes, herein described and shown with reference
to the drawings.
Dated this 2nd day of October 1891
FREDK. WALKER,
11, Furnival Street, London, E.C., Agent for the Applicant.