Note: Descriptions are shown in the official language in which they were submitted.
113~
The invention relates to refractory bodies and finds
particular use as wear:Lng parts for use in the outlets of
metallurgical vecse]s such as casting ladles and tundishes
and as refractory structures for use in outlet control devices
5. for such vessels and in particular slidin~ gate noz21e apparatus.
The invention is described with particular reference to
the casting of steel but, the refractory wearing parts according
to the invention are also applicable to the casting of other
metals which cause considerable wear because of their high
10. melting point or their corrosive nature.
Such apparatus comprises a stationary refractory upper
plate defining a discharge passage and adapted to be located on
the outside of the vessel in Juxtaposition to the outlet orifice
of the vessel, e.g. by being held in a metal frame attached to
15. the shell of the vessel, and a movable refractory sliding plate
defining a discharge pa~sage and rnounted for movement between
an open position inwhich the discharge passages of the two plates
are in register and a closed position ~n which -the movable plate
shuts off the discharge passage of the fixed plate.
20. Movement of the movable plate can be rotatory though a
straight sliding motion is preferred.
One form of such apparatus h~s a fixed upper pla-te and a
movable lower plate. Such apparatus will be referred to herein
as a two plate sliding gate nozzle apparatus. The mo~able plate
25. is preferably mounted for movement in a metal casing, and may
incorporate an outlet nozzle or- cooperate with one which is
also movably mounted in the me~al casing.
Anothèr form of such apparatus has the movahle plate
mounted for movement bet~een upper and lo~er fixed plates and
30. is thus subs-tantially parallel faced and the lol;er fixed pla-te
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incorporates or cooperates with an outlet nozzle. Such
apparatus will be referred to as a three plate sliding gate
nozzle apparatus.
Conventional refractory plates and nozzles for use in
5. such apparatus are made by pressing a refractory granular
mass and then firing it at high ternperature and then drilling
out the outle-t passage.
Refractory wearing parts of the described kind are
exposed in use to wi~ely varying therrr!al stresses. On the
10. one hand such refractory wearing parts are exposed during the
pour to very high temperatures at which me-tals have a maJor
corrosive and erosive action on refractory materials. On
the other hand such refractory wearing parts are exposed at
the start of the pour to an unusually severe and sudden thermal
15. shock which gi~es rise to correspondingly high mechanical
stresses due to differential thermal expansion. For both
these reasons the service life of known refractory wearing
parts of the kind contemplated is short~ For example, on
average a sliding plate requires replacement after only two
20. pours, representing, for example, a total casting time of only
two hours.
According to the present invention a refractory structure
which may be used as a fixed or sliding plate for a sliding
gate nozzie or as a sleeve or nozzle brick for the outlet from
25. a metallurgical vessel comprises A) a body of cast refractory
concrete rnaterial defining at least one discharge passage
- passing through the body and B) at least one reinforcing element,
preferably metallic, located within the body or forming a face
or faces thereof and interlocked mechanically with the refractory
3(). concrete with which it is in intimate contact o~er the whole of
any of its surface which is juxtaposed to the refractory concrete
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or C) means defining at least one duct for a work-ing fluid
intle body or D) the discharge passage being defined by
an insert of material embedded in the refractory concrete
and having bettelr wear resistance than the refractory concrete,
5. or A), B) and C), or A), B) or C) ana D) or A), B)y C) and D).
The metallic reinforcing element is referred to as
being interlocked mechanically with the refrac-tory concrete.
It is to be understood that this means not only arrangernents in
which the interlock is such that the cast refractory concrete
10. body and the reinforcing element car~ot be separated withou-t
breaking one or other of these components, but also arrangements
in which the interlock is at least operative in the situation
in which the plate is actually used so as to resist separation
o~ the cornponents at least so far as shear forces in the principal
15. plane of the plate are concerned.
Thus when the structure is in the form o~ a plate in a
sliding gate nozzle it is held in compression in use, both a-t
its edges and at i-ts opposed pr:incipal faces. It i~1 thus only
essential that the mechanical interlock is sufficient to reslst
20. separation of the cast concrete body from -the reinforcing elern2nt
in a direction parallel to the principal plane of the plate.
However arrangements in which the components are inseparab:Ly
attached to each other are preferred.
An object of the first aspect of the present invention
25. is to provide refractory wearing parts of t~le kind conternplated
in such a way that their service life is extended. The invenliQ1l
achieves this object by making the refractory part of a refrac-tory
concrete and by forming at least one duct in the refraetory
concrete for the c~rculation therethrougil Q~ a workin~ r~1ediur
30. such as a heating or cooling fluid.
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In a first aspect of the invention~ a refractory
wearing part is provided with one or more duc-ts or a system
of ducts formed and distr'ibuted as desired in the wearing
part so as to permit the introduction of a heating or cooling
5. fluid into the interior of the part, where the occurrence of
temperature shock or of undesirably high temperatures in the
material of the refractory part may ~e avoided or reduced.
By appropriately controlling the supply of heating and cooling
fluid it is po'ssible for example to raise the ternperature of
10. the refractory wearing part prior to the start of a pour
sufficiently to obviate the material being damaged by the
temperature shock at the start of the pour. During the pour
the ,temperature peaks which othe~ise arise in the wall of the
passage may be rèduced to an acceptable level by introducing
15. a coolant for a suitable period of time. In this way, on the
one hand, temperature changes can be made to proceed gradually
and, on the other hand, the temperature peaks to which the
refractory part is exposed can be limited to a level at which the
' ' service life of the part will be increased.
20. In a preferred form of the invention the refractory structure
is in the form of a plate, the discharge passage being transverse
to the major plane of ~the plate and the ducts being at least
partially and preferably substantially parallel to the principal
plane of the plate. Preferably the ratio of the maximum longi-
25. tudinal dimension of the sliding surface of the plate to the
minimum thickness of the plate is in the range of ratios of 25:1
to 7.5:1 and more preferably 20:1 to 10:1 and especially 15:1
to 10:1.
In a preferred form of the invention the duc-ts are
30. tortuous. The term "tortuous duct" covers any duct which undergoes
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a change of direction in its passage from its co~mencement
at an inlet aperture to the body to its emer~ence at an
outlet aperture to the body. These ducts may have a
circular or non-circular cross section, such as a rectangular,
5. oval or other cross ~ec-tion. Parts of the ducts may be curved,
others straigh-t and they rnay intercommunicate at an angle,
for instance at a right angle. The ducts may be formed by
metal or ceramic or other heat resistant tubes incorporated
in the refractory wearing parts. Preferably at least the
10. entry to a duct is formed by a metal insert to facilitate
connection of the ducts to a supply of working fluid.
In ano~her embodiment of the invention the refractory
wearing part is of two-part construction, preferably being
divided in a parting plane parallel to its principal plane
15. and one of the components of the piate contains the duct or
ducts with one open side in such a way that when combined with
the other plate component or cover the open side of the duct
or ducts is closed.
The cover is preferably flush with the surface of the
20. plate which may have parallel principal surfaces. Preferably
the inner edge of the cover is spaced away from the edges of
the dischar~e opening. It may consist of refractory material,
e.g. a ceramic or of steel.
The openings of the duct or ducts may be in the cover.
25. Alternatively the inlet and outlet openings may be formed in
the sides or ends of the plate. It is desirable that at least
the inlet opening of the ducts should be formed by a metal
insert to facilitate connecting the duct to a gas or liquid
supply.
30. Refractory wearing parts according to the invention may
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be produced by pouring a refractory co~crete into an appropriate
mould, means determining the duct or ducts of desired cross
section being disposed in the desired position inside the
mould before t~e concrete is poured.
5. The means used fcr forming the duct or ducts may, if this
is desirable, be of a temporary nature, for instance they may
consist of a combustible material such as paper or synthetic
plastics material, so that they can be remo~ed by heating before
the refractory wearing part is used for the first time, or may
10. be such that their removal during first use will not result in
a restriction of the duct cross sec-tion. Alterna-tively the rneans
may also consist of a removable solid material that possesses
the desired shape of the duct and that is inserted in the mould
(as a core) and removed after the refractory part has been
15. moulded, for instance they may consist of a combustihle
material such as paper or synthetic plastics Inaterial, so that
they can be removed by heating before the refrQctory wearing
part is used for the first time, or may be such that their
removal during first use will not result in a restriction
20. of the duct cross section. Alternatively the means may also
consist of a removable solid material that possesses the
desired shape of the duct and that is inserted in the mould
(as a core) and removed after the refractory part has been moulded,
for instance by the application of heat, for instance by making
~5. such a core of a low melting alloy, such as a tin alloy or
Rose's metal. This has the advantage of permitting ducts of
non-circular cross section to be easily produced. Alternati~rely
the duct or ducts may be formed of heat resistant ~etal or
ceramic tubes or pipes.
30. Preferably tne duc-ts are so shaped that they embrace
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the discharge passage traversing the slidin~ plate by
surrounding the same in 'at least 180 arc and preferably
in a 360 circle. In plates having asymmetrically disposed
discharge passages the ducts ~lill with advantage run at
5. least from the middle, preferably from the remote end of
the plate in an at least 180 arc around the discharge
passage and then preferably extend back again at least to
the middle and preferably to the same end of the plate.
The inlet openings into ducts surrounding the discharge
10. passage are preferably tangentially disposed to the circle
to facilitate circulation of the working fluid which may be
heating or cooling ~luid.
The heating fluid and the cooling fluid are preferably
gaseous. With advantage a heating fluid may be a combustlon
15. gas, whereas the coolant may with advantage be compressed air.
The invention also extends to a method of conditioning,
particularly sliding plates in sliding gate nozzles for vessels
containing molten metal, which is characterised in that heating
fluids and/or cooling fluids are circulated through at least
20. one duct contained in the sliding plate.
The invention also relates to refractory structures
containing a gas-permeable insert and adapted for use in or with
25. a vessel which is itself adapted to con-tain molten metal, parti~
cularly for discharge control means on vessels adapted to
contain a metal melt.
Refract~ry structures lncorporating gas-permeable inserts
have been described for example in German Pat. Specn, No. 1935401,
30. German Pat. Specn. No. 2019550, and German as-filed Patent Specn~
No~ 2218155.
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The purposes of the gas-permeable inserts include that of
permitting major volumes of a gas to be introduced under
pressure into the space or cross sectioll provided for the
discharge of the metal melt.
5. When such gas-permeable inserts are provided in
conventional fired refractory plates or nozzles they must
be inserted into pre-bored holes and not inconsiderable
difficulties arise, particularly in quantity production, in
firmly securing them in their holes and in making suitable
10. arrangements for the supply of the gas.
It is an object of the invention to avoid these draw
backs and to provide more simply a refractory component of
the kind contemplated above. In the present invertion this
object is achieved by embedding the gas-permeable insert in
15. refractory concrete from which the refractory component is
formed.
The gas-permeable porous insért is embedded preferably
directly, in the body of refractory con~crete, for instance
by pouring and vibrating the concrete around the inser-t. Ducts
20. for working fluid communicating with the gas permeable insert
may be formed in the in the refractory concrete. ~Iowever, if
desired, the insert may be previously located in a metal surround
in such a way that a cavity remains between an inner face of
the insert and the refractory concrete body9 the gas supply
25. means, for instance a duct moulded into the concrete opening
into this cavity. The ducts extends preferably to a remote end
face of the component. In the case of a slee~e (nozzle brick)
containing a central metal discharge passage or of the fixed
plate of a 2-plate sliding gate noz~le, the gas-permeable inser-c
30. may with advantage extend to the wall of the metal discharge
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passage traversing the part and may encompass the entire
periphery of this passage, thus itself forming the wall of
this passage.
With a sliding plate for a two-plate sliding gate
5. nozzle (i.e. comprising one fixed and one movable plate~,
the gas-permeable insert is preferably located in the
sliding plate and flush with the top face of the latter so
as to be below the discharge passage of -the fixed plate when
the gate is shut. The insert may be adapted to be supplied
10. with gas via a duct extending from one end or side wall of the
plate or the bottom face of the plate.
~ en the inlet is in the bottom face of the sliding
plate of a three-plate sliding gate (i.e. having two fixed plates
and one movable plate in the middle~, access thereto for the
15. gas may be obtained via a duct in the lower fixed plate. This
duct is preferably formed in a cast refractory concrete plate
as described above.
The use of gas-permeable inserts which are embedded in a
refractory component of a 2- or 3-plate sliding gate nozzle
20. made of refractory concrete is of particular importance in
preventing the gates from becoming inoperative by the molten
metal freezing in the discharge passage above the closed
sliding plate. The gas preferably used is an inert gas, such
as argon or nitrogen.
25. The form of construc-tion according to the invention in
which a ~as-permeable or porous insert is embedded in a
refractory part made of refrac-tory concrete 9 for instance by
pouring and possibly compacting the concrete, e.g. by vibratlon9
around the insert, provides an oustandingly reliable bond between
30. the gas-permeable insert and the refractory concrete and
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s~rprisingly there is no significant impairmen-t of the
permeability to gas of the gas-permeable or porous insert.
The gas-permeable insert and the ducts for the working
fluid may be loca-ted on a metal plate which is flush with
5. the underface of the sliding or middle plate.
The working fluid may be conducted to the gas-permeable
insert through an opening in the metal plate ln the bottom of
the sliding plate, which opening communicates with a recess
in the upper surface of the bottom fixed plate, and the recess
10. may be cor~ected to an external gas supply pipe.
Alternatively the working fluid may be conducted to
the gas-permeable insert through an opening in the upper surface
of the sliding plate, which opening communicates wit,h a
recess in the undersurface of the upper fixed plate, and the
15. recess may be co~nected to an external gas suppiy pipe.
The length of the recess is preferably so calculated
and its position so chosen that the closing movement of the
sliding plate uncovers the gas admission from the recess to the
gas-permeable insert when the insert is~in the working position
20. in the metal discharge passage, and the opening movement of the
sliding plate shuts off the gas supply when the gas-permeable
insert withdraws from the discharge passage and the latter
is opened for the discharge therethrough of molten metal.
The invention also extends to cases where the refractory
25. component is in the form of a sleeve or nozzle brick for lining
the well brick of a metallurgical vessel.
The gas-permeable insert may be itself sleeve-shaped and
embedded in the middle of the sleeve. The gas-permeable insert
preferably inserted into a sleeve shaped sheet metal surround
30. before bein~ embedded, so that a clearance remains bet~reen the
outside peripher~ of the insert and the inside surface of the
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metal surround, which clearance serves as a gas distributing
chamber.
The invention also extends to a method of producing
a nozzle brick in accordance with the invention in which the
5. concrete pouring mould comprises an outer form and a central
core for holding the gas permeable insert in the desired position
inside the mould. In a preferred form of the invention a
jacket conforming with the shape of -the form and consisting
of a fire-resistant felt is introduced into the form before
10. pouring begins, and is then firmly bonded to ~e refractory
component O
The gas-permeable insert is preferably soaked with
water before the concrete is poured.
As mentioned above the invention relates to sliding gate
15. nozzles for vessels adapted to contain molten metal, parti~
cularly steel casting ladles and -tundishes for the continuous
casting of steel.
In such sliding gate nozzles thermal stresses (i.e.
mechanical stresses due to differential thermal expansion)
20. often arise ~or which it is very difficult to compensate.
In addition, high thrusts are encountered. These may jointly
give rise to bending and tensile stresses of a severity which
the refractory material of the nozzle plates cannot withstand.
The conditions are unlike those when refractory components
25~ and parts are purely statically loaded such as occur in furnace
- walls or roofs. There it is fairly easy -to~make allowance for
any possib]e thermal stresses and strains. Tensile stresses
can be largel-y avoided and dynamic thrus-ts do not arise.
In conven-tioIlal sliding gate nozzles the above mentioIled
30. severe stresses are in practlce absorbed by embedding the
KDNK/JP 12.
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refractory material in the metal supporting structures
of the gate in a densely compacted layer of mortar which
makes all-overlclose surface contact with the refractory
plate and the suppo~ting structure. Th~ generally accepted
5. solution of the problem is technically satisfactory, provided
it is properly applied. However, it requires skilled manual
work and the functional reliability of the gate depends upon
this work having been carried out with repeatably uniform
precisian. The dependence of ope~atlng safety upon purel~r
10. human factors is a major defect, bearing in mind the freauency
with which the wearing material in sliding gates requires
replacement and the danger o~ a serious steel leakage. An
additional factor is that the service life of the refrac.toy
material located by embodiment in mortar is relatively short,
15. particularly in the case of the orificed plates used for
controlling such sliding gate nozzles as mentioned above.
It is an object of this aspect of the present invention
to provide a sliding gate nozzle for vessels adapted to contain
a metal melt, wherein the above described defects are at least
20. redvced in severity.
This aspect of the invention relates to a sliding ga-te nozzle
for vessels adapted to contain metal melts comprising at least
one fixed and one movable plate, at least one of the plates
being associated with a supporting frame and each plate having
25. an orifice for the passage therethrough of the metal melt,
characterised in that ~ least the movable sliding plate consists
substantially of refractory concrete and on its side facing
away from i-ts slidin~ face is provided with a metal reinforcement
embedded therein wi-thout the use of mortar, said reinforce.rnent
30. being thus anchored in the sliding plate so that tension,
KDNK/JP 13.
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compression or shear forces cannot shlf-t it, the sliding
plate itself being located in -the supporting frame without
the use of mortar and the likewise movable supporting frame
and the reinforlcement preferably incorporating elements for
5. transmitting the thrusts when the gate is operated.
The reinforcement preferably substantially comprises
a metal sheet or a metal plate provided with elements firmly
fitted thereto and projecting Otlt of its principal plane, the
said elements creating the non-shift anchorage of the rein-
10. forcement in the sliding plate against -tensile and brea~ing
forces or thrusts.
The elements projecting out of the principal plane o: the
reinforcement may be tabs integrally formed wi-th the sheet
metal or metal plate of the reinforcement and bent to embrace
15. the sides and ends of the sliding plate. Alternatively the
elements projecting from the principal plane of the reinforcement
may be parts that have been bent out of the reinforcemen-t plate
itself.
In another alternative the elements projecting from
20. the principal plane of the reinforcement rnay be indentations
or corrugations formed in the sheet metal reinforcement or
the reinforcement pla,te. In yet another alternative the
elements projecting from the principal p'lane of the reinforcement
may be projections such as pins welded to the sheet metal
25. reinforcement or reinforcement plate. In a further alternati~e
the sheet metal reinforcement or the reinforcement plate may
be perforated.
The elements for transmitting the thrusts which arise
when the gate is operated rnay comprise ai~utment or elevations
30. on either side of the discharge passage of the molten metal
KDNKJJP 14.
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through the s~pportlng frame, said abutments cooperating
wi-th shoulders formed by the reinforcement.
The abutments on the supporting frame may extend
across the direction of movement of the sliding plate and may
5. consist of ribs extending a distance correspor~ding to the
width of the sl~ding plate and each cooperating with a
complementary shoulder formed by the reinforcernent.
The elements on the supporting frame transrnitting the
thrusts which arise ~en the ga-te is operated may comprise
10. a pin provided at least at one poin-t spaced away from the
discharge passage for the molten metal, said pin engaging
a reinforcement socket in the sliding plate~
The reinforcement may rest on three and preferably
six bearing abutments on the facing surface of the supporting
15. frame.
Preferab]y at least three and preferably four of the
bearing abutments are disposed symmetrically at a distance about the
discharge passage for the molten metal, so that the sliding plate
can freely bend slightly in the axlal direction in the region
20. surrounding the orifice.
The reinforcemen-l; contains an opening in the region of
the discharge passage of the molten metal through the sliding
plate, and this opening preferably has a diameter exceeding
the diameter of the orifice, e.g. by an amount in the range of
25. 120 to 3009'.
,
KDI~IK/JP ~5.
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The invention may be put i.nto practice in various wa~Js
and certain specific ernbodiments w ll be descri~ed by way of
` example to illustrate the in~ention with reference to the
: accompanying drawings, in which~
: 5. Figure 1 is a diagrammatic cross sectional view taken
on the line I - I of Figure 2 of the middle plate of a th~ee-
plate sliding gate nozzle apparatus containing a duct forrned
therein in accordance with a first embodiment of the inventlon~
Figure 2 is a cross sectional view of the plate, taken
10. on the line II II of Figure 1)
Figure 3 is a diagramrnatic plan view of a second embodi-
ment of a middle plate in accordance with the invention con-
ta ming a duct formed therein and a porous insert~
Figure 4 is a cross sectional view of the plate in
15. Figure 3, taken on the line IV - IV of Figure 3~
Figure 5 is a cross sectional view of a modification of
the embodi.ment shown in Figures 3 and 4, taken on the line
V - V of Figure 6,
Figure 6 i.s a diagrammatic cross sectional view taken on
20. the line VI - VI of Figure 5 of the middle plate and of a
partial plan v.iew of the bottom plate of the embodiment shown
in Figure 5,
Figure 7 is a diagrammatic cross sectional view taken
on line VII - VII of Figure 8 of a third embodiment of a middle
25. plate in accordance with the invention,
Figure 8 is a cross sectional view of the plate sho~n
in Figure 7, taken on the line VIII - VIII of Figure 7,
Figure 9 is a diagra~lmatic cross sectional view taken
on the longitudinal centre line, of a fourth em~odiment of a
30. middle plate and of part of the bottom stationary plate in
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accordance with the present inven-tion,
Figure 10 is a cross sectional view of the ernbodiment sho
in Figure 9, taken on the line X X of Figure 9,
Figure 11 is a diagrammatic plan view of the upper surface
5. of the bottom stationary plate of the eMbodiment sho~ in
Figure 9,
Figure 12 is a diagrammatic cross sectional view from a~ove
taken on the line XIV - XIV in Figure 13 of a fifth embodiMent
of a middle p].ate in a three-plate sliding gate nozzle apparatus,
10. provided with a duct that can be directl.y heated,
Figure 13 is a sectional view of the plate shown in Figure.
12 taken on the line XIII ~ XIII in Figure 12~
Figure 14 is a diagrarnmatic cross sectional view of a
sixth embodiment of a middle plate of a 3-plate sliding gate
15. nozzle apparatus con^taining a gas-permeable inser-t embedded
therein in accordance with the present invention,
Figure 15 is a plan view of the~plate shown in Figure 14,
Figure 16 is a cross sectional view of a 3-plate sliding
gate nozzle apparatus for a vessel adapted -to hold a metal melt
20. showing a seventh embodiment of a middle plate in accordance
with the invention which incorporates a gas-permeable insert
embedded in the plate which is sho~m in the open position,
Figure 17 is a cross sectional view corresponding to
Figure 16 showing the middle or sliding plate in the partly
25. closed position,
Figure 18 is a cross sectional view corresponding to
Figure 16 showing the middle sliding plate in the closed position,
Figure 19 is a cross sectional view of a 2-pla-te slidlng
gate nozzle apparatus incorporating an eighth embodiment of
30. the invention namely a sliding plate having a gas-permeable
K~NK/JP ~7
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: insert embedded therein,
Figure 20 is a cross sectional view of a ninth embodirQent
of the invention, namely a nozzl.e containing a gas-permeable
insert in the metal discharge passage of a vessel adapted to
5. hold a metal melt.;
Figure 21 is a diagrammatic sectional view demonstratirig
the way in which the embodiment shown in Figure 2~ can be
produced,
Figure 22 is a cross sectional view taken on the line
10. XXll - XXII of Figure 21 of the gas permeable insert shol~m
in Figure 21,
Figure 23 is a diagrammatic cross sec-tional view of a
tenth embodiment of the invention exemplified by a sliding
plate containing a metal reinforcement;
15. Figure 24 is a view similar to Figure 23 showing a modi.fied
form of construction,
- Figure 25 is a plan view of an eleventh embodlment of
the invention,
Figure 26 is a longitudinal sectional view of the embodi-
20. ment shown in Figure 25,
- Figure 27 is a longitudinal sectional view of a twelth
embodiment of the invention,
Figure 28 is a longitudinal sectional view of a thirteerlt.h
embodiment of the invention,
25. Figure 29 is a longitudinal sectional view of a fourteenth
embodiment of the invention~
Figure 30 is a longitudinal sectional view of a fifteenth
embodment of t;he invention,
Figure 31 is a l.ongitudinal sectional view of a sixteenth
30. embodimen-t of the invention,
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~ F`igure 32 is a view of the embodiment sho~n in Flgure 31
s~en from above,
Figure 33 is a cross sectional view on the line XXXIII -
XXXIII of Figure 32,
5. Figure 34 is a view of a seventeenth embodiment of the
invention seen from above,
Figure 35 and 36 illustrate one way of producing a sliding
plate provided with a metal reinforceMent, and
Figures 37, 38 and 39 illustrate another way of produci.ng
10. a sli.ding plate provided with a metal reinforcement.
~igures 1 and 2 illustrate a middle plate 112 of a con~
ventional three-plate sliding gate nozzle apparatu.s. Other
parts of the apparatus are not shown since sliding gates as
such are kno~n.
15. A duct 150 for conducting a gas or a liquid extends from
an inlet opening 151 roughly in the middle of one of the longer
sides around a discharge passage 106 to an outlet open.ing 152
in the other longer sideO
In an alternative arrangement(indicated by a dot-dash li.ne
20. 153) the duct 150 may extend further around the discharge
passage 106.
In yet another alte~1ative the duct openings 151 and 152
may be formed in one end of the plate 112, preferably at the
end where the mechanism for actuating the plate is located.
25. The duct 150 is preferably formed in the upper half of the
plate 112, i.e. in that half which faces the metal melt, for
example at a height equal to 20 to 50% of the thickness of the
plate measured from the upper surface 141 of the plate 112.
The plate .L12 is made of refractory concrete suitable
30. compositions for ~vhich are given in Examples 1s 2 and 3 below.
KDNK/JP
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1~3~645
The duc-t 150 is formed for example by the provision
of a steel tube in the mould and the refractory concrete is
poured around the -tube. The concrete is then allowed to set,
for example for 12 hours, and the plate is then taken out of
5. the mould and allowed fully to harden for another 48
hours at room temperature.
Instead of providing a steel tube a consumable material
may be used to form the duct. Thus a tu~e made of cardboard or
of a synthetic plastics material can be used which burns away
10. when casting begin~s. Alt~ natively a core of low melting metal,
such as CERROBEND, an alloy of tin, or Rose's metal can be uscd.
This has the advantage that non-circular ducts of any desired
cross section, such as rectangular or oval cross sections can
be easily produced.
15. The CERROBEND material can be xemoved by the application
of heat 7 for instance during the proGess of drying the plate.
The alloy will then melt and run out, a process that can be
accelerated by blowing low pressure steam through the duct.
The discharge passage 106 may be bored through the cured
20. c.oncrete either with a diamond tool or preferably this passa~e
is moulded during the pouring of the concrete by providing a
removable core, and if the passage is cylindrical the core may
be of split construction to faci]itate its extraction.
- Figures 3 and 4 illustrate a modified form of construction
25. of a middle pla-te 112 containing a cooling duct or heating duct
150 and a porous or gas-permeable insert 1560
The plate 112 is composed of two component parts, namely
a body componen-t 160 and a separate cover plate 161 for the d~lCt.
The kody component 160 is first produced, as above descrlbed ~;itl
30. reference -to ~igures 1 and 2, by pouring the concrete into a
mould which forms the duct 1~0, in the present instance formln~
KDl~K/JP 20
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an opèn groove and reba-ted ledges 162 and 16~ .or the cover 161.
The ledge 163 adjoins another recessed. portion 164 which
penetrates to a greater depth into the body componen-~ part ].60
for the purpose of creating a gas distributing chamber surround~ng
5. a porous and gas-permeable insert 1560 The height of -the inser-t
156 is prefe.rably ..;lightly less than the depth of the led.ge i63
so that a clearance 167 remains between the cover 161 and -the
inner face of the insert 156.
The cover 161 may be separately made of the same materlal
10. as the body component 160 and it may be cemented into position
with the same refractory concrete (as indicated at 168). The
cover 161 may be reinforced by casting a metal plate into the
same.
Alternatively9 for some applications w~ere differences in
15. -thermal expansion are not very serious, a steel cover, preferably
of stainless steel, might also be used.
The discharge passage 106 and the inlet 151 and out].et
152 may be produced in the same way as described with reference to
Eigures 1 and 2. Al-ternatively they may be holes in the body
20. component 150 drilled with a diamond drill.
External valve means are preferably provided for the
purpose of allowing a gas e.g. air or nitrogen.to enter through
the inlet 151 and to leave through the outle-t 152 when the
sl.Lding gate is ~pen, escape through the insert 156 being prevented
25. by the upper st~ionary plate (not shown), and in the closed
position of the gate to enable the outlet 152 to be closed and
to cause a gas preferably argon to be dlver-ted to the insert 156
w~ence it escapes through the discharge passage in the upper
stationary plate and enters the molten metal.
30. In an al-cernative embodirnent the inlet and outlet openings,
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as lndicated at 170 and 171, may be formed in the cover 161
and arranged to comm~micate with the gas supply and return
through suitably located grooves in the bottom stationary plate
(not shown). Such an arrangement will be described in greater
5. detail wit.h reference to Figures 9 to 11. A special form of
this arrangement for an outlet is illustrated in Figures 5 and 6
In this instance the outlet 171 from the plate 112 is formed
in the cover 161 and leads across the undersurface of the plate
112 to the outside. The outlet 171 communicates with a longi-
10. .tudinal groove 172 in the upper surface of the bo-ttom stationary
plate 111. When the middle pl.ate 112 is in the casting pos.ition
(open position) one end 173 of the groove 172 extends beyond
the end of plate llZ thereby permitting the hot gas from the
duct 150 to escape from the end 173 of the groove 172 in the
15. bottom plate 111. At the same time the length of the groove 172
is so determined that when plate 112 is moved from its open
into its closed position, the groove 172 will be completely
covered by plate 112 and the gas in the duct 150 will be forced
to pass through the porous or gas-permeable insert 156 into the
20. melt in the metallurgical vessel. This form of construction
¦ clearly has the advantage of greater simplicity compared with the
¦ arrangement in Figures 7 and 4 and of providing automatic control
! f the gas.
I Figures 7 and 8 illustrate a modified form of the construc
i 25. tion of Figures 1 and 2, which includes a porous or gas-permeable
i inser-t 156. In this arrangement the middle plate 112 contains
an insert 175 made of a normal ceramic material or of steel
(ordinary or stainless steel) at the end 142 of the longer side of
the plate. This facilitates the provision of the parts required
¦ ~0. for the gas supply connection and it also serves as a support
.
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for the porous insert 156 and the core for the duct 150 during
! production of the plate9 both being secured, for example, with
a mastic, to the plate 112 whilst the concrete is being poured
into the mould. The duct 150 extends into the proximity of the
discharge passage 106 or in another form of construction it
embraces the same as indicated at 153.
The duct 150 is flattish and extends at a level which is
between 20% and 80S of the thickness of the plate 112 away from
its upper face 141. The porous insert 156 is rectangular &nd
10. disposed between the arms of the duct 150.
In this forrn of construction the above-described CERROBEND
material may be used. The insertion 175 is placed on the bottom
of the mould, the CERROBEND core defining the shape of duc~ 150
is formed and the porous insert 156 so located between the arms
15. of the duct that the CERROBEND material prevents the liquid
refractory concrete from penetrating into the porous insert 156.
The concrete mass is then poured into the mould. After the
casting has set and has been removed and allowed to cure the
CERROBEND material i~ removed by heating or by blowing it out
20. with steam.
The discharge passage 106 is produced as has been described
above and the upper and bottom surfaces of the plate are machined
should this be necessary.
Figures 9 to 11 show another form OI ConStrUCtiQn of the
25. three-plate sliding gate in~hich the middle plate 112 as well as
the bottom stationary plate 111 are of somewha-t different
construction.
A porous insert 156 is located in the longer part of
the middle piate 112 and supplied with gas from a pipe 180
30. through an upward,y recessed openin~ 1~1 in the insert 156.
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The insert 156 and the pipe 180 are located on a metal plate
182 which has aln opening 188 opposite to a corresponding opening
189 pointing do~ ards at the end of the pipe 180. A metal
pipe 184 is provided inside the plate 112 transversely there~
5. to between the insert 156 and the discharge passage 106 and this
has an elltry 185 and an outlet 186 both pointing do~wards~ 185
comm~micating with duct 184~ and 186 with 184b which have openings
in the undersurface of plate ].12.
As will be apparent from Figures 10 and 11 the bo-ttom
10. stationary plate 111 is provided with two parallel groo~es 190
and l91 in its upper face which are covered by the lGwer fase of
the plate 112 and serve as gas ducts. The groove 190 extends
from a metal or ceramic inserted component 192 ser~ing 8.S an
inlet to the end of the plate 111 where it communicates with a
15. -cross groove 19~ extending only across about half the width o*
the plate 111. The other groove 191 extends from a point facing
groove 193 to an outlet 194. In the open posi-tion of the plates
111 and 112 the cold gas is flowing through the opening 19~, the
groove 190 and the opening 184a into the cooling t~lbe 184 from
20. whence it passes at the other end through the opening '84b and
the groove 191 to the outlet 194, through which the hot gas
havlng cooled the plate can freely and safely blow off into the
at~.nosphere.
The pipe 180 is so d.isposed that when the plates 111 and
25. 112 are in the closed position (corresponding to a mo~ement
of the sliding plate 112 from left to right),the opening 188
communicates with groove 193 and gas will be conducted from the
entry 192 through the insert 156. The pipe 184 in this posi-cion
is closed.
30. In Figures 12 and 1~ the !niddle pla-te 112 has a central
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flattened duct 260 which reaches from one end of the plate
112 into the proximity of the discharge passage 106 where it
divides into two oval ducts 261 and 262 that embrace the
discharge passage 106 and have outlets at the other end O L the
5. plate 112. A burner nozzle 264 (or an air lance) is inserted
into the entry opening of the flattened duct 160, permitting
the~ plate 112 to be heated by hot combustion gases. When
an air lance is used the pl~te 112 can be cooled by compressed
air being blo~m through the plate.
10. Although not shown in the drawings the entry openings into
the duct or ducts in a preferred form of construction may
tangentially communicate with the ducts to improve circulation
of the heating or cooling fluid. This arr~ngement is parti-
cularly useful when the duct or ducts surround the discharge
15. passage.
Examples of refractory concretes are hereunder given, SUCh
as may be used for the wearing parts that have been described
above, and for making refractory parts provided with gas-
permeable inserts, particularly for parts of sliding gate no~zles
20. associated with vessels holding molten metal.
EXample 1
80% by weight of an aggregate containing 40% by weight of
A1203 and having a particle size from 0 to 5 mm are ~ixed with
- 20% by weight of a fused alumina cement having a content of
25. 40% by weight of A1203, 12 litres of water being added in
respect of each 100 kg of the dry mix.
For the production of a wearing part this mi~ is poured
into a ~ould and compacted by vibration should this be desirable.
After having sufficiently set the concrete part is taken out of
30. the ~ould, stored to cure and dried.
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80% by weight of ~uyana bauxite containing 88~ by weight
of A1203 particle size 0 to 5 mm was mixed with 20% by
weight of alumina cement containi.ng 70~ by ~eight of A1203
5. and 10 litres of water per 100 kg of ~ry mix. This mix is
further processed as described in Example 1~
However, if th~ plates are tobe used for casting st~els
having melting points above 1500C whlch are cast at temperatures
50C to 60C above their melt.ing points, the conditions
10. which the plates have to wi-thstand are very much more severe
and in order to ensure a more reliable service special compo~
sitions rnust be used.
These conditions consist in a very severe rnechanical
erosive and chemical corrosive attack on the edges of the dis-
15. charge passages of t~ plates combined with extreme thermalshock, the plates before the pour starts having a temperature
of only 200C to 300C.
For such very severe conditions it is preferred to use
refrac-tory concretes containing from 5 to 8% by weight of an
20. alumina cement, 2.5 to 4% by weight of a pulverent refractory
material (having a particle size of less than 50 microns and
I preferably less than 1 micron) such as a ~aolin or bentonite,
micronised silica, micronised al~nina, micronised magnesia,
micronised chromite or micronised fosterite, 0.01 to 0-30S'
25. by weight of an agent effective to increase the flowability
of the composition comprising an alkali metal phosphate, alkali
metal polyphosphate 9 alkali metal carbonate, alkali metal
carboxylate OI' alkali metal hl~.ate and from 87.7 to 92o by
weight of at least one refractory aggregate, desirably having
30. a particle size not exceeding 30 mm, an~ desirably all of which
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pass a 10 mrn mesh and about 25~ of which pass an 0.5 mrn
mesh screen. The refractory aggregate may consist of
calcined refrac-tory clay, bauxite, cyanite, sillimanite,
andalusite, corundum, tabular alumina~ silicon carbide,
5. magnesia, chromite or zircon or mixtures thereof.
An example of such a concrete is given below:
Example ~
.
87.8 to 92% by weight of tabular alumina, particle size 0 - 6
mm are mixed with 5 to 8% by weight of alumina cement con-taining
10. about 80% by weight of A120~, 2.5 - 4% by weight of micronised
alumina and 0.01 to 0.3% by weight of alkali metal poly-
phosphate. 5 litres of water are added per 100 kg of dry mix.
The mix is poured into the mould and can be compacted by
vibration.
15. Fi~ures 14 and 15 illustrate the sliding or middle plate
112 of refractory ooncrete of a 3-plate sliding gate nozzle
apparatus in which a gas-permeable insert 156 ~s embedded.
The insert 156 may be a porous body consisting of a coarse-
grained mass of corundum or mullite sintered with a small quantity
20. of a cementing agent and exhibiting a gas-permeability of at
least 100 nanoperms.
The principal component of the sliding plate 112 is a
pressed or cast body 200 containing a rectangular central window
201. In view of the relatively short-duration of a pour (from
25. the time of filling to the time of completely discharging the
vessel) this body is heated to only a relatively low temperature,
e.g. between 400 and 500C (when casting steel which heats
up the walls of the discharge passage to more than 1500C).
For this reason it ls not absolutely necessary to m~ke -the body
30. 200 of a refractory material. More important is the choice of
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a material that is dimensionally particularly stable and
insensiti~e to temperature shock of the described kind,
so that this body 200 can serve as a durable frame for the
actua] gating portion of the sliding plate 1127
5. The window 201 contains a member 202 which is of the same
thickness as the body 200, but which has a slight clearance in
the window 201 to facilitate replacement.
The member 202 has chamfered edges 203 and a cast-in
cylindrical sleeve 205 which defines the discharge passage 106
10. for the metal through the sliding plate. This sleeve may be
produced by pressing and firing or by casting a highly refractory
mass. Without significantly increasing the cost of a sliding
plate the sleeve may consist of a material of the highest quality,
such as zircon, which can be standardised for size and shape
15. and which will consitute only a small part of the entire volume
of the plate.
The member 202 consists of refractory concrete of a quality
that should be chosen to allow for the aggressiveness of the
molten metal in question. In the majority of cases a concrete
20. as specified above in Example 3 will sa-tisfy the needs of the
case. I~ the member 205, as is preferred, is used, then the
member 202 may be made of a lower quality, such as that
described in Examples 1 and 2 above.
The member 202 contains the gas-permeable insert 156 embedded
25. therein supported by a metal plate 182 which has an opening 188
comrnunicating with an opening 189 at one end of a metal tube 180
of which the other end opens into a distributing chamber 208
at the bottom of the gas-permeable insert 156.
The gas-permeable inser~ 156, the tube 180, and the rnetal
30. plate 1~2 are assernbled and cemented or otherwise joined toge,~her,
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as indicated at 209; before the refractory concrete is poured.
~ igures 16, 17 and 18 illustra-te a 3-plate sliding gate
nozzle apparatus in which the sliding plate 112 corresponds to
the sliding plate in Figures ~ and 15. The fixed plates
5. are marked 110 and 111.
The lower fixed plate 111 is mounted in a supporting
frame 131 in a prepared bed of mortar 1~1'. The metal dis-
charge passage through the 3-plate slidi.ng gate nozzle apparatus
is generally identified by 106~ but the sleeve for lining the
10. discharge passage has been omitted.
In its upper surface the lower fixed plate 111 contains
a recess 154 which communicates wi~h a supply duct 155 and
with a connecting gas pipe 157 for supplying the gas-permeable
insert 156 with gas. When the gate is wide open, as in Figure 16
15. no gas can enterO
However, when the gate is partly closed, as in Figure 17,
the gas entry opening is partly uncovered and some gas already
passes into the discharge passage 106.
Finally, when the gate is fully closed as in E'igure 18~ the
20. gas supply is completely uncovered and the gas flows at maximllm
rate into the discharge channel 106.
The recess 154 is so located in the lower ~ixed plate 111
and it is of a length such that during the closing movement
of the sliding plate 112 the supply of gas to the gas-permeable
25. insert 156 through the gas pipe 157, the gas duct 155, the
recess 154 and the tube 180 will begin when the gas-permeable
insert 156 enters the discharge passage 106, and that a full
rate gas supply to the gas-permeable insert 156 will be assur~d
when the sliding p.late 112 is in closing position.
30. Figure 19 is an embod.iment of a 2-plate sliding gate
KDl~K/JR
~3!~i45
nozzle appara~us in which 165 indicates a sliding plate
co-operating with a fixed plate 169 which in its underfaoe
- contains a recess 177 supplied with gas through a duct 183
and a gas supply pipe 183a.
5. The 2-plate sliding gate defines a metal discharge
passage 106. The sliding plate 165 contains a gas-perrneable
insert 156 which receives the gas through a duct 179 and a
distributing chamber 178. The distributing chamber 178 is
covered by a metal plate 178a. The gas is supplied in the
10. same way as described in the case of the 3-plate sliding gate
; in Figures 16, 17 and 18.
The fixed plate 169 is contained in a holder 174 and
bedded in mortar 176.
~igures 20 to 22 illustrate the ninth embodiment of the
15. invention in its application to a nozzle brick or sleeve.
~, Figure-20 shows a nozzle brick 212 held in position
in a mortar layer 21~ in the bottom b,rick 54 of a vessel
adapted to hold molten metal.
Alternatively, the mortar layer 21~ could be replaced
20. by a jacket of fire-resistant felt or ceramic fibre material.
For the purposes of the invention it is of particular advantage
to secure this jacket to the coned outer surface of the nozzle
brick or sleeve 212 whilst the concrete is being poured. The
, advantage thus achieved is of a dual nature. Though providing
i 25. a good seal the jacket will 210t adhere to the internal wall of
i the bottom brick 54. Hence the more rapidly wearing sleeve 212
can be easily removed without damage being done to the bottom
brick 54, whereas on the othe~ hand the pre~ormed bond between
the jacket and the sleeve ensures both correct positioning of
30. the sleeve and an easy removal of the jacket when the sleeve
212 is removed~
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It is of the essence that the sleeve 212 should
consist of a refractory concrete beGause the operationally
safe application of such a ~acket which forms a layer of
consistent thickness OAnA the peripheral surface of the sleeve
5. 212 demands the observance of close tolerances in Gverall
dimensions and angles during the fahrica-tion of t~e sleeve.
This is assured ~Jhen using a refractory concrete. In the
case of a burn-t material experieAnAce shows tha-t such close
tolerances carAAlot be assured without resorting to expensive
10. subsequeAnt machining.
The refractory ceramic fibre and felt material is
preferably 3 to 4 mm thick, its bulk weight is 170 to 210
kg/cub.rr., e.g. 1~2 kg/cub.m, and the fibre gauge is roùghly
3 to 4 microns. The material is preferably compressible to
15. half its thickness. If the sliding gate nozzle is to be
used in the casting of a metal melt at temperatures up to
about 1260C a suitable felt would contain about 52~o by weight
of SiO2 and 48yO by weight of ~1203. For higher temperatures
up to about 1500C it is advisable to make use of a felt based
20. on a chromium alurninium silicate having a content of for exa~ple
54.5% by weight of SiO2, 42.3% by weight of A1203 and 3.2%
by weight of Cr203 and a melting point above 1650C.
The sleeve 212 contains a gas-permeable insert 215
preferably surrounded b-y a metal cylinder 216 which leaves a
25. clearance creating a gas distributing chamber 217. The end
of the cylinder 216 is sufficiently far a-r~y from the metal
discharge passage 55 to be protected by -the insulating effect
of the refrac-toAry concrete. A ga., duct 218 is provided and
may be defined by a cast--in leng~;h of tube (not sho~n) or i-k
30. may be bored into the brickc The gas rnay -then be supplied
to the pOl'OUS insert through a tube 21~ loca-ted bet~l~een the
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ladle bottom and i-ts brick linin-g and emerging through the
bottom 52 on the outside of the frame 5~ of the plate. If
preferred the tube 219 might also be located bet~een the
bottom 52 and the frame 58 above the fixed plate 67.
5. The sleeve 212 in Figure 21 may be produeed in a mould 222
by pouring with the provision of cores 220 and 221. The core
220 is introduced through the bottorn of the inve~ted mould
form 222 and the metal sleeve 216 together with the insert 215
is placed on the metal disc 216a, which is held by the conical
10. part 223 of the core. If a jacket of refractory felt is to
be interposed between the sleeve 212 and the nozzle brick -to
form a seal, then a preformed coned felt jac~et 21~a is located
inside the form. The core 221 is then positioned on the end of
the core 220. The refractory concrete is poured into the form
15. and the moulding taken out when set to be stored until fully
hardened. Finally the duct 218 is produced by drilling (see
Figure 20).
~ igure 22 relates to particu]ars of a preferred geo-
metrical configuration of the gas-permeable insert 215. This
20. has a generally square cross section and charnfered edges to
enable it to fit into the cylindrical sleeve 216. The four
cavities thus created represent a distributing chamber 217.
Communication between the several cavities is prcvided by
peripheral groo~es 224 and 225.
25.
Gas-permeable or porous inserts for sliding gate nozzle
apparatus fitted to casting ladles can be produced as follows:
Raw material: - High purity corundum of a particle size between
O.5 and 3 mm and between 1 and 3 mm.
30. ~onding agent:-
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a) Clay containing not less than 4390 A1203: up to 5 percellt byweight (particle size 0 to 0.25 mm).
b) Aluminium monophosphate : up to 1.5 percent ky weight ~50%
aqueous solution).
5. Bricks are compacted from this mix under a pressure
of 500 to 600 kp/sq.cm. and the compacted masses are then
kilned for not less than four hours at 1600C.
The physical properties of the bricks are:-
Permeability to gas:- 500 to 700 nanoperm
10. Cold compressive strength:- 2~0 to 350 kp/sq.cm.
A few general explanations will be of assistance:- the
proportion of open pores in volume percent is determined by
the method of "Washburn". In this context it should be
emphasised that the permeable pore ~olu~e may be only a
15. proportion of total porosity.
The gas permeability (according to DIN 51 058) is
measured in nanoperm. 1 nanoperm corresponds to 10 9 perms.
A gas permeability of 1 perm is defined as the gas flow o~
1 cc/sq.cm/sec. driven by a pressure differential of one
20. dyne/sq.cm through a permeable body 1 cm thick, when the
viscosity of the gas is 1 poise.
We refer now to Figure 23. This shows a moveable
sliding plate 63 of a two-plate sliding gate nozzle for a vessel
adapted to contain a metal melt. Such sliding gates are kr.o~m
25. in the art and the fixed plate of the gate is not therefore
shown.
- The sliding plate 63 contains an orifice 55 for the
passage therethrough of the metal melt. It is supported by
a metal frame 64.
30. The side of -the sliding plate 63 facing away from its
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1~3~64S
sliding face is provided wi-th a metal reinforcement 229
in the form of a flat metal sheet or a flat rnetal plate.
The reinforcement 22~ extends across the entire underface
of the sliding plate 63 and it is connected to the plate so
5. that nei-ther tension, compression or shear forces can move it~
For transmitting the thrusts, which arise when the gate
is operated, ~rom the supporting frame 64 to the sliding plate
63,the supporting frame 64 is formed with elevations 232
and 233 which co-operate with correspondingly shaped shoulders
10. 230 and 231 formed by the reinforcement 229. The elevations
232 and 233 on the supporting frame 64 may be ribs extending
across the direction of movement of the sliding plate 63, the
length of the ribs substantially equalling the width of the
sliding plate 63.
15. It will be u~derstood that-the length and width of these
ribs or elevations 232, 233 are arranged to comply with the
demands that arise in any particular sliding gate nozzle. In
Figure 23 the elevations 232 and 233 on the supporting frame
64 are disposed a relatively short distance away from the
20. orifice 55 for the passage of the metal, so that only com-
paratively slight flexing of the sliding plate 63 can occur
in use.
If it is desired that the sliding pla-te 63 should be
capable of more pronounced bending the elevations 232 and
25. 233 on the supporting frame 6~ and the cooperating shoulders
230 and 231 of the sliding plate 63 may be spaced further
apart and more particularly the elevation 232 and the shoulder
230 may be located nearer the end of the sliding plate 63 as
is illustra-ted in Figure 24.
30. It will be understood -that the ?levations 232 and 233
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on the supporting frame 64 and the shoulders 230 and 231
of the relnforcement 225 will be in dlrect engagement when
the sliding gate is operated.
In the embodiment sho~m in Figures 25 and 26 the
5. reinforcement again comprises a flat metal sheet or a flat
metal plate 235. The reinforcement extends over -the greater
part of the underside of the sliding plate 112 and contains
an opening 236 of a diameter exceeding the diameter of the
orifice 106 for the molten metal. Preferably the diameter
10. of the opening in the reinforcement 236 may exceed the
diameter of the orifice 106 by an amount ranging bet~een 120
and 300~o~ preferably from 140 to 2005o. Consequently when
the refractory concrete is being poured during the production
- of the sliding plate the gap between the orifice 106 and the
15. opening 136 in the rein~orcement will fill up with refrac-tory
concrete and the reinforcement 235 will thus be sufficiently
insulated frorn the teeming metal whilst casting proceeds.
The reinforcement 235 is provided wi-th six tabs 237
which are integra]ly formed on the edges of the reinforcement
20. and bent upwards to embrace the sides and ends of the sliding
plate from the outside.
Figures 27 ~ 28 and 29 show three modified e~bodimen-ts
of this type of reinforcement which in each case contains an
opening 236 having a diameter exceeding that of the orifice
25. 106 as has abo~e been described.
~ In the embodi~nent sho~l in Figure 27 the reinforcement
comprises parts 238 and 239 which have been bent out of t~le
general plane defined by the reinforcement. In a ma~ner
similar to the tabs 237 in Figures 25 and 26 thes~ bent parts
30. create a firm anchorage for taking up tension, c~mpression and
KDI~l~;JJP
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shear stress that may arise between the reinforcement and
the body of the sliding plate 112, the allchorage or mechanical
interlocking being created when the plate is being produced
from refractory concrete by cas~ing.
5. In the embodiment sho~n in Figure 28, the reinforcement
contains indentations or depressions 240 which in a sirnilar
way also establish a secure anchorage between the reinforcernent
and the body of the sliding plate. In a modification of this
embodiment the depression 240 are replaced by punched up
10. perforated loops so that concrete can penetrate the loops and
for~ a flush bottom face thereby increasing the interlocking
, between the ref'ractory concrete and the metallic reinforcement.
In the embodiment shown in Figure 29 the only difference
is that the reinf'orcement is perforated ~ 2~4/
15. In all these examples the upper sliding face of the
sliding plate is manufactured so that it is parallel to the
underface of -the reinforcement.
Figure 30 shows a three-plate sliding gate nozzle in
which ~he sliding plate 112 has the f'orm shown in Figures 25
20. and 26. The fixed plates 110 and 111 of the sl:~din~ gate
nozzle are provided with sheet metal reinforcement reser,1bling the
sheet metal reinforcement 235, the upper fixed plate 110 being
provided with the reinforcement on its upper surface and the
lower fixed plale 111 on its underf'ace.
25. The sheet metal reinforcements are each formed with tabs
237, as in Figures 25 and 26~ and these tabs 237 embrace the
sides and ends of the sliding plates ~ , 111 and 112 from
the outside whil.st being embedded therein.
A supportin~ frame 118 is associated with the upper fixed
30. plate 110 and a supporting frame 131 with the lower fixed plate
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111. Both frames 118 and 131 are provided with a plurality of pro-
jections or bearing abutments 245 on their side facing the plate 110
or 111, and the sheet metal reinforcements 235 bear against these
abubments. This ensures that the fixed plates 110 and 111 will be
automatically fitted firmly and correctly without the need to use
mortar.
Should it be desirable, sliding plates which are rein-
forced in accordance with the invention may be reduced in thickness
to less than the thickness attainable by conventional pressed and
fired sliding plates. For instance, the ratio of length to thick-
ness may exoeed 15:1, e.g. 20:1 to 25:1 or even m~re.
Figures 31 to 33 shGw a cast sliding plate 63 containing
lengthwise and crosswide reinforcing elements formed on its under-
side by l-sections 250 and 251 extending along both sides of the
plate and interconnected by three welded transverse plates 252, 253
and 254.
Figure 34 shcws in plan view a sliding plate 312 which con-
tains a metal reinforcement like the above described sliding plates
although this cannot be seen in the illustrated view from above.
anly an opening 314 can be seen which is reinforoe d with sheet metal
in a manner that will be later described with referen oe to Figures
35 to 39.
Bearing elements 315 indicated in discantinuous lines and
conveniently for~ed by suitable elevations or abutments are provided
on that side of the supporting frame (not here shown) which faoe s
the sliding plate. m e reinforcement of the sliding plate 312 rests
on these bearing elements. Consequently the rein~orced sliding
plate 312 is freely suspended in the region of the discharge passage
106. The plate is
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thus capable of slight deformation when subjected to the
ef~ects of forces that arise in use.
The production of a sliding plate according -to this
aspect of the in~ention will now be more particularly
5. described ~rith reference to Figures 35 to 3~.
Figure 35 shows a mould 401 in which the prepar~d rein-
forcement 402 shown in Figure 37 is ~irst placed in position. In
the illustrate~ case the reinforcernent 402 consists of a metal
sheet (or plate) 4~3 containing a tubular sheet metal insertion
10. 404 covered by a cap 405. Projections, for instance in the fol~m
of metal pins or bosses, 406, are welded to the sheet metal rein~
~orcement 403. These pins 406 serv~ to create a mechanical inter-
lock and thus secure anchorage between the relnforcement 402 and
the refractory concrete constitu-ting the sliding plateO In a
15. ~urth~r ~referred modifica~ion we provide the pins 406 with broad
ened heads or tangs or recesses so as to increase the interlocking
of the metal reinforcement to t}le refractory concr~te.
The bottom of the mould 401 contains holes 407 through
which e~ectors 408 can be introduced -to eject, the finished
20. sliding plate from the mould 401. This action is illustrated
diagra~natically in Figure 36.
At the inst,ant lllustrated in Figure 35 the mould 401
has been prepared for the production of the slidlng plate l~y
pouring refractory concrete and compactinO the same, e.g. by
25c vibration. The mould 401 is thu.s filled with refractory
concrete, the surolus concrete being skimmed off over the ed~e
which is machined parallel to the bottom of' the mould 401.
It may be noted that the cap 405 may consist of any
suitable ma~erial since its purpose ~s to pre~ent the
30. refractory concrete from entering the tubular reinforcernent
insertion 404. However, if ~ormed as a welded on steel cap5
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it could also ~ncrease the mechanical interlocking.
Figure ~6 as above mentioned, dia~rarnmatically shows the
plate being Ipushed out o:E the mould as soon as -the concrete
has initially set. The reinforce~ent sheet 402 serves as a
5. support and prev-ents the sliding plate frorn warping in
storage and during further treatment (curing, drying and
so forth). ~t the same time the mould 401 is thus again quickly
available for lurther use.
Figure 33 diagrammatically shows a side elet~ation of
10. part of a supportiIlg frame 411 of conventional kind. Accordi7~g~
to the invention this supporting frame 411 is subsequently
provided with a firmly fittec3 boss or stub 409 which is of
a diameter so calculated that i-t will be a sliding fit in the
tubular insertion ~l04, in the reinforcement 402. .4 flat disc
15. 412 embraces the boss 409.
Figure 7`9 shows the reinforced sliding plate 413 about
to be assembled with the supporting frame 411. The reinforcing
metal sheet 402 rests on the disc 412 ~hich absorbs the
vertical forces, -transmitting the same through the supporting
20. frame 411 to ways not shown in the drawing. The boss 409
inside the insertion 404 provides anchorage for ~;he sliding
plate against horizontal displacement in ~e supporting frame Lll
without, ho~Yever, preventing hori20n-tal thermal expansion.
The boss 409 also takes up the entire thrust when the sliding
25. plate is operated. The transmission of this thrust by the
boS5 409 through the reinforcement 402 to the concrete component
of the plate 413 is effected by elevations 9 projections or
stubs 406 and the tube 404.
The disc-shaped bearing member 412 on the illustrated
30. long side OI +he siiding plate corresponds to at least one
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corresponding abutment on the short side not shown in the
drawing, resembling the abutments 245 in Figure 30 and
315 in Figure 34.
In the above-described embodiment the resultant bending
5. stresses are taken up by the reinforcement~ In the same way
as in the embodiment according to Figure 34 this affords the
advantage that the sliding plate by bending will be relieved
of undue compressive stress due to thermal expansion when
locally heated in the nei.ghbourho~d of the discharge
10. passage forthe molten metal. Furthermore, the provision of
these bearing abutments makes the reinforcement amenable
to precise static calculation.
It must still be mentioned that the boss 409, if desiredS
may be provided with a central bore for the admission there-
15. through of a gas.
Examples of refractory concretes which can be used forthe above sliding gate nozzles are described above in Examples
1, 2 and 3.
In a modification of the arrangements of Figures ~5
to 39 a hole is drilled in the supporting frame 41:L of a
size to accornmodate the tube 404 which is extended downwardly
through the reinforcing element 402 so as to engage the hole
in the frame 411. This tube can then be used as a working
fl~id inlet and within the plate can communicate with a duct
for working fluid.
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