A Method and Apparatus for Separating Dust from Blast Furnace Gases.
Year: 1898

page_text: Date of Application, 21st Mar., 1898-Accepted, 23rd Apr.,
1898
COMPLETE SPECIFICATION.
A Method and Apparatus for Separating Dust from Blast Furnace
Gases.
We, BENJAMIN HOWARTH THWAITE, of No. 29, Great George Street, Westminster,
in the County of London, Civil Engineer, and FRANK LACROIX GARDNER, of
No. 32, Old Jewry, in the City of London, Mining 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 :-
This invention relates to means of separating dust from blast furnace gases as
they descend the "downcomer or pipe by which they are led from the top of the
furnace, as we shall describe referring to the accompanying drawing Fig. 1 of
which is a vertical section of the "downcomer" of a blast furnace provided with
dust separating apparatus according to our invention.
Figs. 2 and 3 are part sections shewing modifications.
A is the "downcomer" having its lower part enclosed in an outer casing B which
dips into water in a vessel C.
In the downcomer A we suspend a barbed or twisted wire D or it might be a rod
or chain having numerous projecting points, or, in the case of a large downcomer
we may suspend several such wires, rods or chains. The vessel C is made with
sloping sides to facilitate the raking of deposit out of it; it is kept supplied with
sufficient water to maintain a liquid seal preventing entrance of air.
The wire, rod or chain D, or each of these when several are used, is attached to a
crosshead E which is supported on columns F of insulating material and is connected
by a conductor G to one terminal of a source of electricity such as can furnish
currents of very high tension as may be obtained from an electrical machine or from
a dynamo and high tension transformer.
The upper part of the wire rod or chain is enclosed within a tube T of non-
conducting material.
As the electricity is discharged from the barbs or points the particles suspended
in the descending gases become separated from the gases, and are deposited in the
vessel C, while the more or less purified gases ascend the annular space between the
downcomer A. and the casing B to an outlet O whence they are conducted to any
place where they are to be utilised as fuel for a gas engine or for other purposes.
Instead of the water seal vessel C, a double valved receptacle H, as shewn in
Fig. 2, may be employed, the upper valve being open and the lower closed while
the deposit is being collected in the receptacle, and the upper valve being closed
while the lower is opened from time to time for removal of the deposited matter.
As shewn in Fig. 3 the lower end of the casing B may be made of considerable
depth with a lateral opening through which deposited matter can from time to time
be withdrawn, a sufficient quantity being always left to prevent access of air.

page_text: Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. The herein described method of separating dust from blast furnace gases by
discharge of high tension electrical currents from numerous points situated in the
course of the descending gases.
2. For separating dust from blast furnace gases, in combination with the
downcomer or pipe for descent of the gases from the furnace a barbed wire or its
equivalent, or several of these suspended in the pipe and having the upper end or
ends connected to the terminal of a source of high tension electrical currents,
substantially as described.
3. In combination with the apparatus referred to in the preceding claim, a
casing for the downcomer forming an annular passage for ascent of the gases, and
having at its base means of receiving and withdrawing deposited matter without
permitting access of air, substantially as described.
3
1
L
1000
ABEL & IMRAY,
Agents for the Applicants.