An Improved Feeding Device for the Grates of Boiler Furnaces.
Year: 1895

page_text: Date of Application, 5th Feb., 1895-Accepted. 4th May, 1895
An Improved Feeding Device for the Grates of Boiler Furnaces.
I, MAX OSCHATZ, of Meerane in the Kingdom of Saxony, Manufacturer, do
hereby declare the nature of this invention, and in what manner the same is to
he performed, to be particularly described and ascertained in and by the following
statement:-
This invention refers to boiler-furnaces, in which the grates are arranged in an
inclined position, and my improvements in furnaces of said kind relate to the
combination of two of such grates (one of which is inclined to the right, the other
to the left) with a trough arranged between said two grates, and containing in its
lowest portion a conveyer-worm adapted to feed the coal upon the grates in a
perfectly uniform manner.
In order to make my invention more clear, I refer to the accompanying
drawing, in which similar letters denote similar parts throughout the different
views, and in which:
Fig. 1 is a vertical section through a furnace provided with my improved feeding-
device;
Fig. 2 is a vertical section through a modification,
Fig. 3 is a front-view of the masonry of a boiler, showing the outer feeding-
device; and
Figs. 4-7 are several modes of construction of the conveyer-worms used for the
troughs.
Referring to Fig. 1, a¹ a² are two inclined grates having between them a
trough b, the latter is comparatively deep, and contains in its lowest part a
conveyer-worm e driven by means of any suitable gearing, for instance in the way
shown in Fig. 3.
Trough 6 projects beyond the front-surface of the furnace-masonry (Fig. 3) and
is connected by means of a large tube d with a main-trough or reservoir e
containing a conveying worm f. If there are more than one double-grates, I prefer
to employ one main-trough or reservoir only for all of them.
The arrangement of the two grates belonging to a trough may with regard to
the latter be altered in the manner shown in Fig. 2. The coal instead of falling
downwards, as in the first mode of construction, is in this second mode of
construction pushed or shoved upwards, which is also caused by the conveyer-
worm c. The latter is in either case perfectly prevented from being damaged by
the heat of the burning fuel, as, first, the coal contained within the upper portion
of the trough is conveyed upon the grate according to its getting ignited, and as,
second, the trough is intensively cooled by the air washing the trough on its way
to the two grates.
The spiral wings of the conveying-worms c may be constructed in various ways,
as shown for instance in Figs. 5-7, but I prefer the mode of construction shown
in Fig. 4, in which the shaft of the conveyer-worm provided with several spirals
running in contrary directions, and having preferably different degrees of pitch.
These several spirals are best arranged in such a manner, that the degree of pitch
decreases from the front to the rear of the trough (c).
Having now particularly described and ascertained the nature of this inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a furnace having one or more pairs of inclined grates, the combination

page_text: with the two grates forming a pair, of a trough arranged between said two grates,
and having a worm adapted to convey the coal along within said trough, and to
transfer it from the trough upon the said two grates, substantially as described.
2. In a furnace having one or more pairs of inclined grates, the combination
with the two grates forming a pair, of a trough arranged between said two grates,
and having a worm adapted to convey the coal along within said trough, and to
transfer it from the trough upon the said two grates; said conveying-worm having
two or more groups of threads, running in different directions, substantially as
described.
3. In a furnace having one or more pairs of inclined grates, the combination
with the two grates forming a pair, of a trough arranged between said two grates,
and having a worm adapted to convey the coal along within said trough, and to
transfer it from the trough upon the said two grates; said conveying-worm having
two or more groups of threads, running in different directions, and having different
pitches, substantially as described.
Dated this 5th day of February 1895
MAX OSCHATZ,
By Geo. H. Rayner,
37, Chancery Lane, London, Agent for the Applicant.