Note: Descriptions are shown in the official language in which they were submitted.
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Docket F-650
SYSTEM FOR PREVENTING CLOGGING OF THE OUTLET
ORIFICE OF A DISPENSER TANK CONTAINING POWDERED
REAGENT AND AUXILIARY TANK DISCHARGE MEANS
TECHNICAL FIELD
A finely powdered reagent such as Calcium Car-
bide, Salt Coated Magnesium, Calcium Silicone and the
like is supplied to molten ferrous metal in order to
effect a desulphurizing or alloying action or both as
is explained in U.S. Patent 3,929,464 issued December 30,
1975 and titled Desulphurization of Molten Ferrous Metals.
BACKGROUND ART
Known dispenser tanks containing powdered re-
agent and having an orifice through which the powdered
reagent may flow into a carrier gas conduit arranged to
receive and to convey the powdered reagent to a point of
use such as a pool of molten metal have a tendency to
lS operate improperly due to the formation of lumps or
globules of reagent or introduction of foreign matter
particles which tend to interfere with or to close entirely
the outlet orifice of the dispenser tank.
DISCLOSURE OF INVENTION
For the purpose of preventing partial or complete
blockage of the discharge orifice of a dispenser tank and
in accordance with the features of this invention, the dis-
charge orifice of said invention is in communication with a
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Docket F-650
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carrier gas conduit arranged to receive and to convey the
powdered reagent to a point of use, whereby an arrangement
including a plunger having a diameter less than the diameter
of said discharge orifice and being reciprocably movable
through said discharge orifice, engages and crumbles globules
of material which are of sufficient size and orientation so
as to interfere with the normal discharge of the powdered
reagent through the orifice. Operating means are disposed
within the dispenser tank for imparting reciprocable movement
to the plunger, and a closure element for the orifice is
mounted on and is movable with the plunger and is arranged
so as to engage and to disengage a part of the dispenser tank
adjacent to but spaced from the discharge orifice so as alter-
nately to prevent and to allow the passage of the powdered
reagent through the discharge orifice respectively.
According to another feature of this invention
the closure element for the orifice is configured in such
manner as to provide space for accommodating powdered re-
agent located adjacent the dispenser tank orifice so as toprevent impactment of the reagent at the orifice, the
reciprocable operating means for the closure element and
plunger being enclosed by extensible enclosing means which
prevents abrasive action of the powdered reagent with respect
to the reciprocable operating means, and emergency discharge
means in the form of a conduit which extends through a wall
of the dispenser chamber may be provided and is controlled
by a control valve outside the dispenser tank so that pres-
sure within the dispenser tank may be utilized to discharge
powdered reagent from the tank into a collector tank for
subsequent use after the emergency condition is corrected.
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Docket F-650
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BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings FIG. 1 is a schematic diagram
of a powdered reagent dispensing system which incorporates
features of this invention; FIG 2 is an enlarged
partially broken away view of the operating means for
reciprocating a plunger through the outlet orifice of a
dispenser tank and for moving the tank orifice closure
element between open to closed positions; FIG. 3 is an
enlarged cross sectional view of the lower portion of a
dispenser tank showing its orifice, a plunger constructed
according to this invention as well as the closure element
configured according to a feature of this invention, the
parts being shown with the closure element and plunger
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Docket F-650 -3-
in the uppermost orifice open position; FIG. 4 is a view
similar to FIG. 3 but which depicts the plunger during
its passage through the dispenser tank orifice and FIG. 5
is similar to FIGS. 3 and 4 and shows the closure element
and plunger in their lowermost orifice closing positions.
BEST MODE OF CARRYING OUT THE INVENTION
In FIG. 1 ~he numeral 1 designates a dispenser
tank including a supply of powdered reagent 2. Reagent
is supplied through a conduit 3 from a source not shown
into a receiver chamber 4 in which a screen filter 5 is
mounted for jostling vibratory movement imparted thereto
by vibrator 6. Valve Vl controls the inlet 7 to tank 1
so that during filling operations, valve Vl of course
is open whereas this valve is closed during normal
operating conditions during which powdered reagent 2 is
supplied through orifice 8 into carrier gas conduit 9
for transmission through conduit 9 and lance 10 into the
pool 11 of molten metal in ladle 12.
Convey gas at pressure Pl is supplied from
20 reservoir 13 and pressure regulator 14 to conduit 9.
Pressure P2 within dispenser tank 1 is maintained at a
level in excess of pressure Pl in conduit 9 by means of
regulator 15 disposed in conduit 16 which interconnects
fluid reservoir 13 and dispenser tank 1.
Thus under normal conditions the higher
pressure P2 forces powdered reagent 2 through the outlet
orifice 8 and into conduit 9 through which it is conveyed
by carrier gas under pressure Pl into the pool of molten
metal 11 so long as the orifice 8 is in opened condition
as represented in FIGS. 1 and 3.
Because of their characteristics some reagents
tend to lump up, especially when exposed to moisture.
Occasionally foreign matter, such as slag, rust, paper
fasteners and the like are also found in the reagent.
Since the orifice 6 opening is small, these lumps or
foreign matter or both may partially or completely close
the orifice 8. In order to overcome this condition
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Docket F-650 -4-
and in accordance with one feature of the invention,
a reciprocable plunger 17 is arranged for reciprocable
movement through the orifice 8 as is represented by
FIGS. 3, 4 and 5. Such movement of course crumbles
the globules or foreign matter which interfere with the
free passage of reagent through orifice 8 and such
crumbled material then is swept away through conduit 9
in the normal manner. For the purpose of imparting
reciprocable movement to plunger 17, operating means 18
is provided and includes a cylinder 19 and its associated
piston (not shown in the drawings) to which piston rod
20 is connected. Operating movement is imparted to the
piston within cylinder 19 by pressure gas from reservoir
13 supplied through conduit 21 valve V2 and either conduits
22 or 23 as is obvious from FIG. 1 so as to impart up and
down movement to plunger 17 and the piston rod 20. Valve
V2 is of the four-way type and is of well known construction.
This valve may be operated manually by an observant
operator who by suitable instruments realizes that the
orifice 8 is partially or completely clogged. Valve V2
also could be operated automatically in response to a
changed condition such as increased flow of gas
in line 9, or a reduction in the material rate o flow in
the system as is obvious to those skilled in the art.
Alternatively the valve V2 may be operated at timed
intervals so that whether the orifice 8 is clogged or
not the reciprocable plunger 17 in timed sequence
reciprocates through the orifice 8 and ensures that any
obstacle is removed.
The closure element for orifice 8 is specially
configured according to this invention in order to
prevent compacting powdered reagent by trapping the
reagent between the closure element 25 and the orifice 8.
Thus as is apparent particularly in FIGS. 3, 4 and 5,
the closure element 24 is hollowed as indicated at 25
to provide a generally cup-s~haped configuration. Thus
as the plunger 20 moves downwardly any powdered reagent
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Docket F-650 -5-
in the vicinity of orifice 8 is not cornpacted in such
manner as to close off the orifice 8 but instead is
provided with space 25 which accommodates the powdered
reagent disposed below closure element 24 and thus
prevents packing or clogging of the finely powdered
reagent at the orifice 8 which could be caused by the
downward motion of closure eIement 24.
Since the powdered reagent 2 is finely divided
material and because pressure within dispenser tank 1 is
sometimes higher than the operating pressure supplied to
cylinder 19, it is desirable to isolate the interior
of cylinder 19 as well as the exterior of the piston
rod 20 from contact with the abrasive reagent 2 and from
the pressure within dispenser tank 1 and to prevent the
powdered reagent from contacting the sealing rings R.
Toward this end a first bellows 26 is secured at 27 in
fluid tight manner to supporting flange 28. At its
right hand end, bellows 26 is secured at 29 in fluid
tight relation to spacer ring 30 which is disposed about
piston rod 20 and through which that rod is reciprocable.
A second bellows 31 is secured at 32 by fluid tight
connection with spacer ring 30 and is secured at 33 to
ring 34 secured to piston rod 20 and movable therewith.
Thus as the piston rod 20 reciprocates to and fro, the
bellows structure 26 and 31 extends and contracts and all
the while serves to isolate the interior of cylinder 19
and the exterior of piston rod 20 from reagent 2 and
from the pressure within dispenser tank 1. Sealing rings
R are arranged to provide a fluid tight relation between
the aperture formed in flange 28 and the exterior surface
of piston rod 20 which is reciprocable through the aperture
in flange 28 as well as a mechanical guide for the piston
rod 20.
With reference to FIGS. 3, 4 and 5, it is
apparent that downward motion of plunger 17 to the position
represented in FIG. 4 effectively removes any globules
of powdered reagent that may partially or completely
clog the orifice 8. Furthermore, the space 25 in
eup-shaped closure element 24 provides accommodation for
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Docket F-650 -6-
any powdered reagent in close proximity to the
orifice 8 so that orifice closing motion of closure
element 24 does not itseIf compact the powdered reagent
and thus effectiveIy block the passage 8.
It is possible that impurities such as small
granules, rag, rust, slag and metallic fragments may
effectively clog the orifice 8 and such clogging action
may not be fully relieved by reciprocable action of
plunger 17. Such a condition is difficult to relieve
and may even be quite hazardous. Thus in order to
facilitate corrective action, it is desirable first to
remove any powdered reagent 2 which may be within the
dispenser 1 when such firmly clogged condition develops.
Toward this end a discharge conduit 35 may be provided
and arranged with its inner end 3~ closely adjacent the
orifice ~. Valve V3 can then be opened so that
pressure P2 effectively drives the reagent 2 upwardly
through conduit 35 and into collector tank 37 where the
reagent may be retained temporarily for subsequent0 loading into the dispenser 1 for later reuse.
INDUSTRIAL APPLICABILITY
This invention is well suited for use in
conjunction with known systems for dispensing powdered
reagent into molten metal for the purpose of desulphuri-
zation, alloying or both because it substantiallydiminishes or eliminates the difficulties and waste of
time and eort normally required to correct a clogged
orifice in a dispenser tank in systems of this nature.
