EP3103562B9 - Template - Google Patents

Description

The invention relates to a template, which has a frame-shaped or box-shaped, preferably downwardly slightly tapered, configuration with a circumferential wall and a box-like design also has a bottom for the production of molds or a wear layer in metallurgical vessels by drying a warmabbind , in the space between the wall of the vessel on the one hand and wall and possibly bottom of the template on the other hand filled, Rieselmasse.

In steelmaking, the liquid steel is first passed into a vessel designed as a tundish or distributor, which is provided with a heat-resistant lining. This cladding is applied by within the intermediate container a mold, called stencil, is attached, which leaves a small distance to the wall of the intermediate container, in which a dry Rieselmasse (wear mass) is given, which then sets by heating the stencil and solidifies. The same applies to metallurgical casting molds.

From practice it is known that the heating is done by hot air, burners or infrared radiation, for which appropriate equipment needs and must be operated.

The object of the invention is to provide a way by which the heating without such additional equipment is feasible.

This object is achieved in that at least the wall and, if present, the bottom of the template are each formed of a current-conducting, resistance-flow-heated material, wherein the wall and possibly ground each at the two furthest away points two power connection points to form each have a heating element and that in box-shaped configuration, the wall and the bottom are insulated from each other. In this case, the wall and / or the bottom can be advantageously formed exclusively of an electrically conductive, resistance-heated material in the flow of current. The two furthest points of the wall with the two power points are in turn adjacent to each other, but are isolated from each other, so that the current must take the "long way" through the wall and thus heated. The same applies to the ground.

In this case, there is the circumferential wall of a plurality of superposed, adjoining and complementary to the wall circumferential strip-shaped portions, wherein adjacent strip-shaped portions are isolated from each other. As a result, the conductor cross-section (of the individual portions) is lower than in a fully high wall, so that the power requirement is lower. Advantageously, the height of the individual subregions 15 cm to 50 cm, in particular about 30 cm, amount.

Here, the current is passed directly through the template and the template itself represents the "resistance wire", which formwork and heating energy production are combined in one component. Since thus no intermediate components or transmission media are used, which would worsen the overall efficiency by their partial efficiencies, it is an energetically particularly economical process, with the very high efficiencies of over 90% can be achieved.

Significantly higher temperatures than usual in the prior art can be realized, the maximum temperature is limited in principle only by the choice of materials of the template and the insulators and the power supply, which in the future Rieselmassentechnik then new binder systems can be used.

The slightly tapered design, if provided, may have an obtuse interior angle, for example from 93 ° to 105 °, preferably approximately 98 °, between the peripheral wall and the bottom.

According to the invention, at least the wall and the bottom of the template can each be formed from a metallic material, preferably from a heat-resistant stainless steel alloy, which has an electrical resistance that is advantageously high for resistance heating.

In a preferred embodiment of the invention, the wall or the partial areas of the wall may each comprise plate elements and corner elements, wherein the settlement along the height has a uniform length, so that as uniform as possible heating along the longitudinal extent is given.

According to the invention, the corner elements may consist of several layers of sheet metal and have the same total material thickness as the plate elements, so that a flexible corner design is given and the resistance values are unchanged there compared to the plate elements. The corner areas can thus accommodate expansion on heating and shrinkage on cooling.

Preferably, at least one corner element for a deflection of about 90 ° can be bent several times, which easily a corresponding deflection can be realized.

Advantageously, at least one corner element in the region of its two outer edges each have a contact strip placed thereon on the surface, so that in this way a defined electrical connection is provided.

Furthermore, the bottom of a plurality of juxtaposed, adjoining and complementary to the ground strip-shaped portions may exist, with adjacent strip-shaped portions are isolated from each other. As a result, the conductor cross section (of the individual subregions) is smaller than in the case of a single bottom part extending over the entire width of the bottom, so that the power requirement is lower. Advantageously, can the width of the individual sections 15 cm to 50 cm, in particular about 30 cm, amount.

According to the invention adjacent strip-shaped portions may be interconnected by a screw with electrical insulation, so that a stable and releasable connection with standard fasteners is given. This may apply to the subregions of the wall and / or the floor in each case with each other, but also for the connection of portions of the soil with portions of the wall.

Also, the wall and / or the floor or at least one strip-shaped portion of wall and / or floor with in particular transversely to the longitudinal extent, d. H. arranged to the current flow direction, this portion and provided along the longitudinal extent at a distance from each other provided stiffeners that have no effect on the resistance heating even with a welding attachment along the entire length due to their orientation.

Also, the wall and / or the floor or at least one strip-shaped portion of wall and / or floor may be provided with at least one along the longitudinal extension of this portion arranged stiffening, which may be welded only at certain points.

For a good and uniform over the level of current coupling, the power connection points of the wall as over the height of the wall reaching copper strips and / or the power connection points of the floor as over the width of the bottom reaching copper strips and / or the power connection points of the sub-areas than the height or Be formed width of the portions of the wall reaching copper strips.

In a preferred embodiment of the invention, the wall and the floor or the partial areas of the wall and / or the partial areas of the floor can be connected to one another in series by suitable connecting elements connected to the power connection points in an electrically conductive manner.

Preferably, the wall and / or the floor can be flexibly connected to a central frame, so that expansion / shrinkage is possible with temperature changes without high stresses in the material of the template.

In this case, the central frame, preferably over a provided counterweight and / or pneumatic or hydraulic cylinders, be designed to be restoring, so that upon cooling, a corresponding provision is made.

Preferably, the stencil can be at least partially closed on the top side by a cover and / or a fan for circulating the air located in the interior of the stencil can be provided. The cover insulates the internal air, which also reduces heat losses and results in more uniform heating. The latter is also achieved by air circulation by means of a blower. In addition, an air exchange can be effected by the fan in the cooling phase, which shortens the cooling time

The object underlying the invention is also achieved by a system with a template according to one of the preceding claims for the production of a wear layer in metallurgical vessels or molds by drying a warmabbindenden, in the space between the wall of the container on the one hand and wall and possibly ground the stencil on the other hand filled, trickle, the system comprises a connectable to a power supply, preferably thyristorized, current transformer for transforming the current into a small voltage, preferably protective extra-low voltage, to which the template is electrically connected. Depending on the capacity of the current transformer temperatures of about 450 ° C in 2 to 5 minutes are reached, and the drying of the hot-setting Rieselmasse then takes place in about another 5 min.

Fig. 1

eine perspektivische Darstellung eines Teilbereichs einer erfindungsgemäßen Schablone,

Fig. 2

eine Draufsicht des Gegenstands nach Fig. 1,

Fig. 3

eine seitliche Außenansicht des Gegenstands nach Fig. 1,

Fig. 4

eine erste perspektivische Ansicht eines Eckelementes,

Fig. 5

eine zweite perspektivische Ansicht des Gegenstands nach Fig. 4,

Fig. 6

eine seitliche Außenansicht des Gegenstands nach Fig. 4,

Fig. 7

eine Innenansicht in Längsrichtung des Endbereichs des Gegenstands nach Fig. 1,

Fig. 8

eine Innenansicht in Längsrichtung des mittleren Bereichs des Gegenstands nach Fig. 1,

Fig. 9

das Detail "X" des Gegenstands nach Fig. 7 und

Fig. 10

das Detail "Y" des Gegenstands nach Fig. 2.

In the following, an embodiment of the invention shown in the drawings will be explained. Show it:

Fig. 1

a perspective view of a portion of a template according to the invention,

Fig. 2

a top view of the subject Fig. 1 .

Fig. 3

a lateral outside view of the subject Fig. 1 .

Fig. 4

a first perspective view of a corner element,

Fig. 5

a second perspective view of the article according to Fig. 4 .

Fig. 6

a lateral outside view of the subject Fig. 4 .

Fig. 7

an interior view in the longitudinal direction of the end portion of the article according to Fig. 1 .

Fig. 8

an interior view in the longitudinal direction of the central region of the article after Fig. 1 .

Fig. 9

the detail "X" of the object after Fig. 7 and

Fig. 10

the detail "Y" of the object after Fig. 2 ,

In all figures the same reference numerals are used for identical or similar components.

Fig. 1 shows a perspective view of part of a template 1 according to the invention for the production of molds or a wear layer in metallurgical vessels by drying a warmabbindenden Rieselmasse. In this case, the partial area shown is slightly more than half of the approximately mirror-image in plan view 1 template. The symmetry axis AA is in Fig. 2 located.

The template 1 in this case has a box-shaped, slightly tapered down configuration with a circumferential wall 2 and a bottom 3.

As well as out Fig. 3 it can be seen, the circumferential wall 2 consists of a plurality of superimposed, adjoining and complementary to the wall 2 circumferential strip-shaped portions 4, wherein adjacent strip-shaped portions 4 are isolated from each other. In addition, the subregions 4 of the wall 2 each comprise plate elements 5 and corner elements 6 along their longitudinal extent.

The design and construction of the corner elements 6 is in the FIGS. 4, 5 and 6 shown in detail. As far as can be seen, the corner elements 6 consist of several layers of sheet metal 7, wherein the layers of sheet metal 7 together have the same material thickness as the plate elements 5. The corner element 6 is bent several times for a deflection of about 90 ° (see. 4 and FIG. 6 ).

Corner elements 6 are likewise provided between the partial regions 4 of the wall 2 and the partial regions 4 of the bottom 3. These can consist of several layers of sheet metal 7, but they can also be like the plate elements 5 consist of a continuous solid material. The corner regions at which the respective corner elements 6 of the bottom edges and a corner element 6 of the wall meet, can be closed otherwise, for example by appropriately connected and current-carrying metal fabric or the like.

In the region of the two outer edges of each corner element 6, which are likewise aligned obliquely in accordance with the tapered design of the template 1, a patch contact strip 8 made of copper is provided on the surface for a defined electrical connection.

As in the Figures 2 . 7 and 8th shown, there is also the bottom 3 of a plurality of juxtaposed, adjoining and complementary to the bottom 3 strip-shaped portions 4. Again, adjacent strip-shaped portions 4 are isolated from each other. This also applies to adjacent strip-shaped portions 4 of wall 2 on the one hand and bottom 3 on the other.

In this case, the connection of adjoining subregions 4 is provided by a screw connection 9 with electrical insulation in the form of mutual flange bushes 10 and insulator plates 11 arranged between the abutting edges of the subregions 4 (cf. Fig. 9 and 10 ). The same also applies to the connections of plate elements 5 with each other or with corner elements 6. For this purpose, each corresponding angled edge portions at the abutting edges of the sections 4 and the plate elements 5 or the corner elements 6 are provided.

As in the FIGS. 1 and 7 shown, the plate members 5 of the wall 2 transversely to the longitudinal extent, ie the current flow direction, this portion 4 arranged stiffeners 12.

The subregions 4 of the wall 2 and the subregions 4 of the base 3 are connected to one another in series by suitable connecting elements 13 connected to power connection points 14 in an electrically conductive manner. This is for example in the FIGS. 1 to 3 as well as 7 and 8 recognizable.

The first and last partial region 4, as seen in the direction of current flow, is connected in an electrically conductive manner at the beginning or at the end with connected connecting elements 15 to a power supply, not shown in the drawing, which may for example be a converter. This is in Fig. 1 shown.

In that regard, the current flow takes place via the first connecting element 15, which is connected via the power connection points 14 to a first plate element 5 in the uppermost row. The current flow continues via a first corner element 6, a front-side plate element 5 and a second corner element 6 into a further plate element 5 which runs parallel to the first plate element 5. Since the illustrated template 1 is designed to be mirror-symmetrical overall, it continues analogously. After the current has flowed through the uppermost portion 4 of the wall 2, it continues via a connecting element 13 into the next lower partial area 4 of the wall 2, and so forth. Subsequently, a connection is then made to the first plate element 5 of the bottom 3 and then to the second plate element 5 of the bottom 3. From here, a connection then takes place via the second Connecting element 15, which is connected to the end of the last plate element 5 of the bottom 3.

Claims (16)

1. Template (1), comprising a frame-shaped or box-shaped configuration, preferably tapering slightly downwards, with a circumferential wall (2), and, with the box-shaped configuration, also with a base (3), for the production of casting moulds or of a hard-facing layer in metallurgical vessels, by the drying of a heat-setting free-flowing mass filled into the intermediate space between the wall of the vessel on the one hand and the wall (2) and the base (3) respectively of the template (1) on the other, characterised in that at least the wall (2) and, if present, also the base (3) of the template (1) are formed from an electrically conductive material, which undergoes resistance heating when subjected to an electric current flow, wherein the wall (2) and floor (3) if applicable comprise in each case, at the two points most widely separated from one another, two electric current connection points (14), for the formation in each case of a heat conductor, and that, with the box-shaped configuration, the wall (2) and the base (3) are insulated from one another,
   wherein the circumferential wall (2) consists of a plurality of circumferential strip-shaped part regions (4), arranged above one another and adjacent to one another, and supplementing the wall (2), wherein adjacent strip-shaped part regions (4) are insulated from one another,
   and wherein the two points of the wall most widely separated from one another, with the two electric current connection points, are in turn adjacent to one another but insulated from one another, such that the current must take the "long way round" through the wall, and therefore heats it, with the same also applying to the base.
2. Template (1) according to the preceding claim, characterised in that at least the wall (2) and the floor (3) of the template (1) are formed in each case from a metallic material, preferably of a heat-resistant special steel alloy.
3. Template (1) according to any one of the preceding claims, characterised in that the wall (2) or the part regions (4) of the wall (2) respectively comprise in each case plate elements (5) and corner elements (6), wherein their extent along the height exhibits a unitary length.
4. Template (1) according to any one of the preceding claims, characterised in that the corner elements (6) consist of multiple layers of sheet (7) and overall have the same material thickness as the plate elements (5).
5. Template (1) according to claim 3 or 4, characterised in that the corner elements (6) are canted in a multiple manner such as to form a deflection of approximately 90°.
6. Template (1) according to claim 3 to 5, characterised in that at least one corner element (6) comprises in the region of its two outer edges in each case a contact strip (8) located on the surface at that point.
7. Template (1) according to any one of the preceding claims, characterised in that the base (3) consists of a plurality of strip-shaped part regions (4), arranged next to one another and adjacent to one another and supplementing the base, wherein strip-shaped part regions (4) adjacent to one another are insulated from one another.
8. Template (1) according to any one of the preceding claims, characterised in that strip-shaped part regions (4) adjacent to one another are connected to one another by a screw connection (9) with electrical insulation.
9. Template (1) according to any one of the preceding claims, characterised in that the wall (2) and/or the base (3) or, respectively, at least one strip-shaped part region (4) of the wall (2) and/or the base (3), are provided with bracing elements (12), preferably arranged transverse to the longitudinal extension of this part region (4) and provided at a distance from one another.
10. Template (1) according to any one of the preceding claims, characterised in that the wall (2) and/or the base (3), or, respectively, at least one strip-shaped part region (4) of the wall (2) and/or the base (3) are provided with at least one bracing element arranged along the longitudinal extension of this part region (4).
11. Template (1) according to any one of the preceding claims, characterised in that the electric current connection points (14) of the wall (2) are formed from copper strips extending over the height of the wall (2) and/or the electric current connection points of the base (3) are formed as contact strips (8), preferably copper strips, extending over the width of the base (3), and/or the electric current connection points (14) of the part regions (4) are formed as contact strips (8), preferably copper strips, extending over the height or width respectively of the part regions (4) of the wall (2).
12. Template (1) according to any one of the preceding claims, characterised in that the wall (2) and the base (3), or the part regions (4) respectively of the wall (2) and/or the part regions (4) of the base (3) are electrically conductively connected to one another in series by suitable connection elements (13) connected to the electric current connection points (14).
13. Template (1) according to any one of the preceding claims, characterised in that the wall (2) and/or the base (3) are flexibly connected to a central frame.
14. Template (1) according to the preceding claim, characterised in that the central frame is configured such as to be reset, preferably by means of a counterweight provided and/or by pneumatic or hydraulic cylinders.
15. Template (1) according to any one of the preceding claims, characterised in that the template (1) is at least partially closed on its upper side by a cover, and/or is provided with a blower fan for circulating the air present in the interior of the template (1).
16. System with a template (1) according to any one of the preceding claims for producing a hard-facing layer in metallic vessels or casting moulds, by the drying of a heat-setting free-flowing mass filled into the intermediate space between the wall of the vessel on the one hand and the wall (2) and the base (3) respectively of the template (1) on the other, characterised in that the system comprises a current transformer, which can be connected to an electric current supply, for transforming the current into a low voltage, preferably a safety extra-low voltage, to which the template (1) is electrically connected.

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