Improvements in and relating to Reverberatory and Roasting Furnaces or the like.
Year: 1889

page_text: Date of Application, 6th Mar., 1889
Specification Accepted, 13th Aor., 1889
COMPLETE SPECIFICATION.
Improvements in and relating to Reverberatory and Roasting
Furnaces or the like.
1, WILHELM PRICKARTS, Managing Director of "Kl. Grasbrook" Copper Works
Hamburg in the Empire of Germany 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 furnaces, such as reverberatory and roasting furnaces, in
which ores or other matters are exposed to heat upon a hearth or bed and require to
be turned over, stirred or agitated during the process and ultimately removed.
Heretofore in such processes the operations of stirring and removal, or that of removal
only, have generally been performed by manual labour with suitable rakes etc.
The object of the present invention is to construct such furnaces and provide the
same with certain mechanical devices by which the stirring etc. as aforesaid may be
performed and by which at a suitable time the ore or inatter treated may be removed.
Reference being made in the accompanying drawings-Fig. 1 is a vertical longitu-
dinal section through the hearth or bed of such a furnace with parts adjacent thereto,
and fitted with the improvements--Fig. 2 is a plan view of the hearth and stirrers
and Figs. 3 and 4 illustrate in vertical section on a larger scale, the construction of
the stirrers and the manner of arranging and operating them.
I provide for each hearth two or more vertical shafts, passing through the hearth
and roof or covering of the hearth and journalled or supported in suitable bearings-
Each shaft carries two projecting horizontal arms at a suitable distance above the sole
of the hearth and the shafts are placed so that the distance between them may be but
slightly greater than the radius of the horizontal arms-The side walls of the hearth
are shaped to follow the outline of the figure described by the arms on the shafts as
indicated in Fig. 2. The arms on each shaft are diametrically opposite to each other
and their length will be determined according to the width of the hearth. The number
of shafts will vary according to the length of the hearth-To the aforesaid arms are
secured the shanks or rods of a number of spades, shares or rakes so that the latter
are dragged on the hearth by the revolution of the shafts. In the drawing, P is the
hearth. sss are the shafts and bb etc. the horizontal arms carrying the spades or

page_text: the like m, the number of which as well as the length and shape of them and their
connecting rods or shanks, will vary according to the exact mode of operation
desired The alternate shafts are revolved in opposite direction from above or below
by suitable gear such for instance as the bevelled gear shown. The action of the
spades or the like will remove the material from the hearth after the slides or registers
covering or closing the chutes a a have been removed so as to permit of the passage
of the material through said chutes.
To enable a stirring device as just described to be used in a furnace where great
heat is employed, and at the same time to improve the air feed to the hearth by
heating the air the shafts ss etc. and the arms thereon are made hollow, the interior
of each shaft communicating with its arms, and being open or provided with openings
below and above, or either below or above, for the entrance of cold air. The
extremities of the arms are open, so that the air passing through the shafts and arms
issues from the latter in a warmed state and also tends to keep the shafts and arms
cooler by its passage through them.
Since the spades or like stirrers are exposed to wear and have to be at times
replaced, they are secured on the arms preferably in the following manner-The
arms bare straight and slightly tapered conically towards their outer ends, so that the
tubes R may be slid thereon and secured by a screw threaded annulus S or other like
collar or device-On the tube R are strung the perforated bosses of the spades or other
devices m, the same being spaced along the tube R by lengths of tube between them as
shown in Fig. 3-The bosses may be connected with the spades m or actual operating
devices in the manner shown in Fig. 4-For renewal or readjustment of the
spades m the whole tube R carrying the spades etc. may be removed and the spades etc.
replaced or adjusted thereon at leisure and the tube R replaced. Suitable openings
are provided in the furnace wall for removal of the tubes R.
The air may be caused to pass through the shafts and arms, by pressure from
without, or by suction produced for instance by the draught of the furnace shaft or
-chimney or by an ejector provided therefor.
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 ;-
In reverberatory or other furnaces having a hearth P substantially as and for the
purposes referred to.
1) The construction of stirring apparatus whereby the same is cooled' by an air foed
for the hearth, and the said air feed is heated by the stirrer.
2) The combination of hearth P shaped substantially as set forth, chutes a a thereto,
and rotary stirring devices having arms bb and relatively arranged substantially as
set forth.
3) The combination with the hearth P. of the hollow shafts & s¹² etc. and hollow 4
arms bb etc. on said shafts and communicating with the hollow space therein
whereby an air feed is provided substantially in the manner and for the purpose
described.
4) A rotary stirring device having arms b, in combination with tube R and spade
holders or equivalent devices spaced upon said tube,; and an opening or openings in
the wall of said furnace whereby said tube R may be removed for the purpose set
.forth.
Data: ret T