Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to a spray lance for a
flame gunning device for repairing partially damaged
portions of refractory linings of refining vessels such
as converters for steel making, and more particularly to
S a lance for spraying melted or sintering or semisolid
refractory against walls of vessels such as steel making
converters, while cleaning raised bottoms of furnaces
with accumulated adhering substances.
~ method of repairing partially damaged portions
of refractory lining of refining vessels such as steel
making converters has been known as a repairing method
disclosed in United States Patent No. 3,g83,078.
This repairing method is referred to as wet
gunniting process wherein pulverized refractory, pulverized
s~lid fuel and oxygen are sprayed through a nozzle at a
front end of a lance against a furnace wa:ll surface of a
refining vessel at a high temperature 9 for example,
1,350-1,500C immediately after delivery or removal of
melt steel from the furnace so that the damaged or consumed
portion of the refractory lining is coated with the
melted or semisolid refractory produced from the pulverized
refractory by fuel combustion to join the melted refractory
with the lining refractory.
The spray lance for use in the gunniting process
has one end ro-tatably supported on a movable trolley 3
and the other curved end 1 to which is fixed a nozzle 2
directing in a radial direction of a lance tube axis
(Fig. 1). With this arrangement, as only one nozzle 2 is
used to repair the cylindrical wall of the refining
vessel, the lance is required -to have the curved end.
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Such a conventional spray lance serves only to repair a
lining partially or locally and requires much time for
repairing a wider area.
It is an object of the invention to provide an
improved lance which eliminates the disadvantages of the
prior art.
It is another object of the inven-tion to provide
a lance having a plurality of nozzles directing in various
directions and selectively closable by plugs to be able
to freely adjust the delivery amoilnt, range and directions
of the reparing material and combustible gas to effectively
repair refractory walls in the most preferab!e condition.
It is a further object of -the invention to
provide an improved lance which is not only capable of
repairing furnace walls but also cleaning adhesives
accumulated on bottoms of the furnaces.
The invention will be more full~ understood by
; referring to the following detailed specification and
claims taken in connection with the appended drawings.
Fig. l is a perspective view of a conventional
flame gunniting device and a lance as above mentioned;
Fig. 2 is a schematic sectional view of one
embodiment of a lance according to the invent:ion;
Fig. 3 is a schematic sectional view of another
embodiment of a lance according to the invention;
Fig. 4 is a sectional view taken along a line
IV-IV in Fig. 3;
Fig. 5 is a further embodiment of a lance
according to the invention; and
Fig. 6 is ano-ther embodiment of a lance according
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to the invention.
Referring to Fig. 2 illustrating one embodimen~
of a lance according to the invention, the lance 12
consists of four concentric tubes to form four passages
18, 19, 20 and 21, the central flow passage 18 for flowing
therethrough a repairing material (MgO and carbon powder)
together with a carrier gas (N2), the annular flow passage
19 surrounding the central flow passage 18 for flowing an
oxygen gas (including more -than 50% oxygen), and two
outer annular passages 20 and 21 communicating with each
other and surrounding the passages 18 and 19 for flowing
feeding and returning cooling water. ~s an alternative,
the central passage 18 may be used for the oxygen gas,
and the annular passage 19 for the repairing material.
The lance 12 is provicled in outer cylindrical
surfaces and front end with a plurality of nozzles 16
respectively communicating with the central passage 18
and the annular passage 19. The nozzle 16 consists of an
inner nozzle pipe 16a to form a passage communicating
with the central passage 18 and an outer nozzle pipe 16b
concentric to the inner nozzle pipe 16a to form a passage
communicating with the annular passage 19. The nozzles 16
extend branched from the passages of the lance 12 away
from an axis Q thereof and the nozzle at the fron-t end of
the lance extends in the axial direction. In the embodiment
shwon in Fig. 2, the nozzles on the cylindrical surfaces
are inclined to the axis Q of the lance in consideration
of flow resistance of the powder flowing through the
central passage 18. On the other hand, Fig. 3 illustrates
nozzles 16 radially outwardly extending from a lance 12.
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The lance 12 may be provided with only one
nozzle 16 or a plurality of nozzles 1~ as the case may
be. Such a plurality o-f nozzles 16 are preferably arranged
along at least one generator of ~he cylindrical lance.
The lance with thus arranged nozzles is advantageous for
repairing wider areas of a wall at a time, and is also
applicable to local or partial repairing of the wall by
plugging some of the nozzles as shown at 26 in Fig. 3.
The use of the plugs 26 controls the directions and
amount of the oxygen and repairing materials and sprayed
areas to effect the repairing dependent upon positions
and degrees of the damaged portions without any superfluous
effort.
Fig. 5 illustrates a further embodiment of the
invention, wherein a lance 2 includes a furnace bottom
cleaning structure for removing adhesives on a furnace
bottom. The adhesives would decrease a volume in a
furnace and be res-ulting from insufficient slag removal
as in an upper blown converter or the like requiring
agitation gas to be blown into the converter through the
furnace bottom. In order to effect the cleaning operation,
a nozzle 16 is not provided at the front end of the lance
and a front end of a passage 18 for the repairing material
is closed at 24 to form a cleaning opening 23 which opens
in an axial direction of the lance and communicates with
the annular passage 19 for the oxygen gas. With this
arrangement, when the lance is inserted into the converter,
the cleaning opening 23 is in opposition to the furnace
bottom, so that part of the introduced oxygen gas contac-t-
ing the high temperature adhesives on the furnace bottom
burns so as to melt the adhesives to ensure the cleaning
of the bottom. As an alternative, if the central
passage 18 is used for the oxygen gas, the cleaning
opening 23 may be arranged at a location corresponding to
the central passage 18.
An embodiment shown in Fig. 6 is substantially
the same as that shown in Fig. 5 with exception of nozzles
radially o-utwardly extend.
As can be seen from the above explanation, the
lance according to the invention can effectively perform
aimed repairing of linings of furnaces to bring good
results in life, cost and rate of operation of the furnaces.
In addition, the lance according to the invention has a
remarkable advantage in hot repairing a refining furnace
which is not only capable of repairing wider areas of a
furnace wall at a time but also simultaneously cleaning a
furnace bottom.
While the invention has been particularly shown
and described with reference to preferred embodiments
thereof, it will be understood by those skilled in the
art that the foregoing and other changes in form and
details can be made therein without departing from the
spirit and scope of the invention.
