Note: Descriptions are shown in the official language in which they were submitted.
CA 02648094 2008-12-29
DESCRIPTION
SHUTTER MECHANISM FOR RAW MATERIAL LOADING CHUTE OF ELECTRIC
FURNACE
Technical Field
The present invention relates to a shutter mechanism for
a raw material loading chute of an arc resistance type electric
furnace enabling a molten metal to be obtained by smelting
reduction of an oxide ore by carbon.
Background Art
As a conventional art, an apparatus for recovering
platinum group elements from various substances containing
platinum group elements, such as used petrochemical catalysts,
used automobile exhaust gas purification catalysts, and used
electronic substrates, lead frames, etc., is known (see Japanese
Published Unexamined Patent Application No. 2005-54201) .
In the known art, a granular substance to be treated,
containing platinum group elements, a granular copper source
material, containing copper oxide, a solid reducing material
(powder coke) , and a granular flux are mixed together and loaded
into a sealed electric furnace. That is, these loaded raw
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materials are respectively weighed out from a hopper, mixingly
conveyed by a screw conveyor, and fed into a material loading
chute of the electric furnace. The material loading chute is
provided with two stages of shutters, that is, upper stage and
lower stage shutters to maintain an airtight state during loading
of the raw materials into the electric furnace. First, the
upper stage shutter is opened and the lower stage shutter is
closed to load just a single batch of raw materials into the
material loading chute, and then the upper shutter is closed
and the lower shutter is opened to load the single batch of
raw materials retained inside the material loading chute. When
loading of the single batch of raw materials into the electric
furnace ends, the upper and lower shutters are closed in
preparation for a subsequent loading operation.
In a general Fe-Ni ferroalloy manufacturing method
employed in Japan, after pre-reduction of a Ni oxide ore in
a rotary kiln, the ferroalloy is made by smelting and reducing
by carbon in an arc resistance type electric furnace (Elkem
furnace).
As shown in FIG. 6, calcined ore at 1000 C that has been
pre-reduced in a rotary kiln is transferred by means of a
refractory container and retained in a raw material loading
tank, and the retained calcined ore flows by gravity down a
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raw material loading chute and is thereby supplied into an
electrical furnace set at 1300 C. A grate is disposed at a
portion of the raw material loading chute near the electric
furnace, and to stop the supplying of the raw material, round
steel rods are manually inserted in a transverse direction of
the raw material chute into a plurality of round holes formed
in a outer circumference of the grate to cut off the flow of
the raw material.
Disclosure of the Invention
An object of the present invention is to provide, in
an arc resistance type electric furnace enabling a molten metal
to be obtained by smelting reduction of an oxide ore by carbon,
a shutter mechanism for raw material loading chute of
electrical furnace enabled to adjust and stop supplying of a
raw material by provision of a sliding gate plate that performs
percussive hammering on a grate of the raw material loading
chute and to perform remote operation for the purpose of
safety.
A shutter mechanism for raw material loading chute of
electric furnace according to the present invention is provided
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with a gate plate (1) that moves reciprocatingly while performing
percussive hammering on a grate of the raw material loading
chute in the vicinity of the grate.
The shutter mechanism for raw material loading chute of
electric furnace according to the present invention has,
disposed in the vicinity of the grate of the raw material loading
chute, a sliding bed plate (5) , driven reciprocatingly by an
air motor (21) on the grate of the raw material loading chute,
an air pick (20) , installed on the sliding bed plate (5) and
performing percussive hammering, the gate plate (1) , connected
to a front end of the air pick (20) , and disposed at the grate,
a slit groove, guiding the gate plate (1) .
The gate plate (1) is constitutedof a flat, heat-resistant
steel plate and a front end of the gate plate (1) is configured
as an inclined blade edge.
A plurality of heat-resistant tamping rods are fixed in
parallel and at equal intervals on the blade edge of the gate
plate (1) .
The shutter mechanism for raw material loading chute of
electric furnace according to the present invention enables,
by arrangement of just a compressed air source and an operation
cable, remote operation without having to enter near the grate
of the raw material loading chute.
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An aspect of the invention relates to a shutter
mechanism for raw material loading chute of electric furnace
comprising: a sliding bed plate on the grate of the raw
material loading chute, an air motor for driving the sliding
bed plate reciprocatingly, an air pick installed on the said
sliding bed plate, a gate plate connected to a front end of the
air pick, wherein the said gate plate is disposed in the
vicinity of the grate of the raw material loading chute, and
moved to opening or shutting the grate reciprocatingly, while
performing percussive hammering on the grate by the air pick.
Effects of the Invention
The shutter mechanism for raw material loading chute
of electric furnace according to the present invention provides
an effect that, by providing the gate plate that moves
reciprocatingly while performing percussive hammering on the
grate of the raw material loading chute, the gate plate can be
opened and closed without causing inability to operate the gate
plate.
The shutter mechanism for raw material loading chute
of electric furnace according to the present invention
provides, by use of an air equipment, effects of dust cleaning
and cooling of the entire apparatus by an exhaust of a solenoid
valve, an exhaust of the air motor, and an exhaust of the air
pick.
With the shutter mechanism for raw material loading
chute of electric furnace according to the present invention,
relief from adverse conditions, adverse environment, and
dangerous work is achieved by safe, remote operation of raw
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material preparation and opening/closing work solely by button
operations from outside the electrical furnace.
Brief Description of the Drawings
FIG. 1 is a plan view of a shutter mechanism for raw
material loading chute of electric furnace according to the
present invention.
FIG. 2 is a sectional view of the shutter mechanism
taken on line A-A of FIG.1.
FIG. 3 is a side view of the shutter mechanism as
viewed from a direction of an arrow B in FIG.1.
FIG. 4 is a plan view of the shutter mechanism for
raw material loading chute of electric furnace according to the
present invention in a closed state.
FIG. 5 is a longitudinal sectional view of the
shutter mechanism for raw material loading chute of electric
furnace according to the present invention in a closed state.
FIG. 6 is a schematic view of a conventional raw
material loading chute of electric furnace.
Description of Symbols
1 Gate plate
2 Guide cell
3 Fixed frame
4 Fixed frame
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Sliding bed plate
6 Drive unit base
7 Wire tension bracket
8 Clamp plate
5 9 Guide plate
Guide plate
11 Blanking plate
12 Wire roller
13 Scraper
=
10 14 Air pick clamp
Sprocket fixing bracket
16 Head shaft
17 Drive shaft
18 Air pick chisel
15 19 Air pick chisel receiver
Air pick
21 Air motor
22 Coupling
23 Speed reducer
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24 Head sprocket
25 Drive sprocket
26 Drive sprocket
27 Drive sprocket
28 Chain tensioner
29 Chain
30 Chain
31 SD shackle
32 Hinged bolt
33 Wire rope
34 Gate receiving roller
35 Gate receiving roller
36 Gate receiving roller
37 Heat resistant packing
40 Solenoid valve
Best Modes for Carrying Out the Invention
An embodiment of a shutter mechanism for raw material
loading chute of electric furnace according to the present
invention shall now be described based on the attached
drawings.
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A shutter mechanism for raw material loading chute of
electric furnace according to the present invention is shown in
a plan view in FIG. 1, and in a sectional view taken on line A-
A of FIG.1 in FIG. 2. FIG. 3 is a side view of the shutter
mechanism as viewed from a direction of an arrow B in FIG. 1
with illustration of a raw material loading chute portion being
omitted.
As shown in the sectional view of FIG. 2, an air
motor 21, driven by compressed air upon switching of a solenoid
valve by remote operation solely by a button operation from
outside the electric furnace, is disposed inside a lower frame
of a rectangular fixed frame 3, and a speed reducer 23 is
connected via a coupling 22 to an output shaft of the air motor
21.
As shown in the side view of FIG. 3, a drive sprocket
26 of a drive shaft 17 of guide cells 2 is connected via a
chain 29 to a drive sprocket 27 of the speed reducer 23, and a
drive sprocket 25 is furthermore disposed on the drive shaft
17.
As shown in FIG. 2, the drive sprocket 25 is
connected via a chain 30 to a head sprocket 24 of a head shaft
16.
Number 15 in FIG. 3 indicates a sprocket fixing
bracket, and number 28 indicates a chain tensioner.
As shown in the side view of FIG. 3, at a central
portion of the fixed frame 3, the guide cells 2 are disposed on
a drive unit base 6, and a reciprocatingly moving sliding bed
plate 5 is disposed across the guide cells 2. As shown in
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FIG. 3, the drive sprocket 25, around which the chain 30(FIG.2)
is wound , is disposed between the two guide cells 2, the guide
cells 2 support the plate 5 from below, the guide cells 2 are
clamped by plates 8 and the plate 5, and the plate 5, fixed to
the chain 30, is moved by the driving of the chain 30. The
drive unit base 6 is a supporting member corresponding to being
a roof plate suspendingly fixing the air motor 21 and the speed
reducer 23.
An air pick 20 that performs percussive hammering is
installed on the sliding bed plate 5 and an air pick chisel 18
that transmits the percussive hammering is pressingly secured
inside the air pick 20, and the air pick 20 is fixed by an air
pick clamp 14.
To the air pick 20, compressed air from an air
pressure source is supplied upon switching of a solenoid valve
40 by remote operation by just a button operation from outside
the electric furnace, a pair of wire rollers 12 are disposed at
respective sides via the clamp plates 8, and to ends of wire
ropes 33 wound around the wire rollers 12, hinged bolts 32 are
fixed via SD shackles 31 respectively in a manner enabling
percussive hammering.
A gate plate 1 is constituted of a flat, heat-
resistant steel plate, and a front end of the gate plate 1 is
formed to a knife-shaped blade edge that is bilaterally
symmetrical at the top and rear, and a plurality of heat-
resistant tamping rods are fixed in parallel and at equal
intervals to the blade edge.
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An air pick chisel receiver 19, disposed at a rear
end of the gate plate 1, is connectedly fixed to the air pick
chisel 18.
Number 7 in FIG. 2 indicates a wire tension bracket.
A short cylinder, provided with flanges at upper and
lower portions, is disposed on a grate of the raw material
loading chute, a slit groove, into which the gate plate 1 is
inserted, is disposed at one side of a circumference of the
short cylinder, and the same slit groove and a blanking plate
11, closing off the slit groove in a blanking manner, are
disposed at an opposite side.
A fixed frame 4 is disposed at the gate plate 1 side
of the slit groove of the short cylinder, and the fixed frame
3, on which the air pick 20 is disposed, is connectedly fixed
to the fixed frame 4.
Upper and lower gate receiving rollers 34, guiding
the gate plate 1 along the slit groove, gate receiving rollers
35, supporting a horizontal movement of the gate plate 1 from
below, and gate receiving rollers 36, guiding respective side
surfaces of the gate plate 1, are respectively disposed on the
fixed frame 4.
Because dust flies when the gate plate 1 is pressed
in and drawn out, two guide plates 9 and 10 are disposed across
a heat-resistant packing 37 at a gate plate 1 entrance portion
of the slit groove, and a scraper 13 is disposed at an upper
portion of the entrance of the slit groove.
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Operation and action of the shutter mechanism for raw
material loading chute of electric furnace according to the
present invention shall now be described based on the attached
drawings.
When, to close the grate of the raw material loading
chute from a standby state shown in FIGS. 1 and 2, the solenoid
valve 40 is switched by remote operation from outside the
electric furnace and compressed air is supplied to the air
motor 21 via an unillustrated air hose to thereby drive the air
motor 21, a rotation shaft of the coupling 22 also rotates, the
speed reducer 23 connected to the rotation shaft is driven, the
drive shaft 17 is driven via the drive sprocket 27, the chain
29, and the drive sprocket 26, the chain 30 is driven by the
drive sprocket 25, and the sliding bed plate 5 fixed to the
chain 30 advances.
Meanwhile, by switching of the solenoid valve 40 by
remote operation from outside the electric furnace, compressed
air is supplied via an unillustrated air hose to the air pick
20, and by reciprocating percussion, the gate plate 1 is made
to repeat percussive hammering via the air pick chisel 18 and
the air pick chisel receiver 19.
As shown in a plan view in FIG. 4 and a longitudinal
sectional view in FIG. 5, the gate plate 1 connected to the air
pick 20 of the sliding bed plate 5 is guided along the slit
groove, advances in the grate of the raw material loading chute
in the direction of the blanking plate 11, and cuts off the
loading of raw material from the raw material loading chute.
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Because in this process, the gate plate 1 is
repeating the percussive hammering, large clumps of the raw
material are crushed by the plurality of tamping rods on the
blade edge of the gate plate 1 and the raw material tamped by
the blade edge of the gate plate 1 is discharged from a gap of
the blanking plate 11.
Because the grate of the raw material loading chute
is thus closed by the gate plate 1, the supplying of the raw
material by the raw material loading chute can be cut off.
To restart the supplying of the raw material, the air
motor 21 is driven in reverse so that the slide bed plate 5
retreats, and because the gate plate 1 thus retreats while
repeating percussive hammering, the grate can be opened
smoothly without succumbing to a load pressure from the raw
material loading chute.
Furthermore, by stopping the gate plate 1 at any
position, the raw material supply amount can be adjusted.
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