• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    1447721 Ceramic bodies resistant to thermal stress GROUPEMENT POUR LES ACTIVITES ET AVANCEES 31 Jan 1974 [9 Feb 1973 16 April 1973] 04661/74 Heading B2E [Also in Divisions Cl and H2] An element, e.g. of a pump for moving liquid metal e.g. Al 2 in which thermal stresses are reduced, comprises a refractory core 1', a surface provided with grooves 53, 54, 61 or covered with refractory plates arranged non- contiguously to provide grooves therebetween and a filling for the grooves which is more compressible than the refractory core material and impermeable to the molten metal. The core matrial is preferably ceramic as are the plates, the plates being less dense than the core. The plates may be adhered to the core with a mixture of a ceramic binder and alumina and/or silica fibres. The filling may be compacted fibres of alumina and/or silica. Slots may end in borings e.g. 51, 52, 60. When grooves are formed on the surface of the core, the surface spaces between the grooves may be covered with non-contiguous plates which form further grooves.
    公开号:SU867330A3
    申请号:SU742001380
    申请日:1974-02-08
    公开日:1981-09-23
    发明作者:Десклев Пьер；Меньен Жан-Клод
    申请人:Групман Атомик Альзасьен Атлантик (Фирма)；
    IPC主号:
    专利说明:

    (54) PRODUCT
    The invention relates to equipment components used in the non-ferrous metallurgy industry, in particular to pumps for transferring liquid molten metals, the bodies of which are subjected to thermal shocks during immersion and extraction; them from the melt. A product is known, preferably a pump casing, subjected to repeated thermal shocks when it is repeatedly immersed in a liquid medium, for example, in an aluminum melt. 1 The disadvantage of this product is that when an article made of a ceramic material with high surface destruction energy has a low thermal conductivity , a small modulus of elasticity and a low Poisson's quotient, immersed in a high-temperature liquid medium, for example, in an aluminum melt, an abrupt jump instantaneously occurs temperature in the thin surface layer of this block. In accordance with the properties of the material, this surface layer tends to be exposed to heat. expanded, while the remaining internal mass of the ceramic block of the product continues to retain its original temperature, since this layer forms part of the ceramic block, this surface layer, being part of the block of the product, cannot move away from it, therefore it is subjected to compression, which may have great meaning, or not. In addition, when the product is removed from the high-temperature environment and immersed in an environment with a much lower temperature, surface cooling occurs, causing tensile forces limited by the outer layer. It is known that these alternating compressive and tensile forces generate cracks. This phenomenon will be obvious, the more noticeable, the less heat-conducting material used and the lower its resistance to compression and tension. This is exactly what happens when products are made of low-refractory low-conductive material, such as ceramics. This phenomenon will also occur in pump housings that have a ceramic lining, which are used when working with a melt.
    metals, and in which fire resistant low-conductive cladding material serves as thermal protection.
    The purpose of the invention is to increase the service life of the product.
    This goal is achieved in that the product is predominantly in the pump casing, subjected to repeated thermal shocks when it is repeatedly immersed in a liquid medium, for example, in molten aluminum, and filled with refractory material, on its surfaces there are slots filled with refractory material, more compressible than the product itself.
    In order to reduce the stress concentration, each slot inside the product ends in a cylindrical channel.
    In addition, the slots are filled with felt, as well as with fibers from alumina or silica or mixtures thereof.
    There are several types of cuts on the surfaces, i.e. several methods to protect the product from destruction.
    The first method of product protection, i.e. the pump casing consists in cutting in the mass of refractory material, periodically spaced slots of the grooves supplemented, if necessary, with a second network of grooves perpendicular to the previous grooves to create rectangular platforms separated by grooves. These grooves are filled with cotton wool or felt made from very thin compact refractory fibers.
    The second method of product protection consists in coating the smooth surface of a refractory product with non-adjacent plates made of a refractory material less dense than the base material and therefore less thermally conductive. These plates are associated with a refractory base material with a mastic composed of molded refractory fibers bonded with an inorganic binder and ceramic binder in the form of a liquid or paste. The slot of the groove formed by the spacing of the plates is filled, as in the previous method, with cotton wool or felt of refractory fiber. This gasket provides double protection on the one hand, it does not allow hot liquid to come into thermal contact with the underlying layer and, on the other hand, it protects the mastic, which anchors the plates and which can react with the liquid, from contact with this liquid.
    The third method of fabricating the structure is to combine the above methods and cut each ceramic element processed to protect it from thermal shock, one or more rows of cuts, depending on the nature of the surface to be protected, then perform the appropriate bores at the ends of the cuts located closer to the center, and finally in filling the slots and drillings with a pad of cotton wool or felt of refractory fibers ..,
    In some cases it is more advantageous for the slot to end simply with a more or less noticeable rounding in order not to weaken the mechanical strength of the product, significantly reducing the likelihood of an intermittent zone.
    Q on the basis of the slot.
    The invention is illustrated by the example of an electromagnetic pump, which is intended to be transferred immersed in an active molten metal, such as aluminum.
    FIG. 1 shows schematically a view from the front to the outer surface of the housing of a magnetohydrodynamic pump, processed in accordance with the first two methods; in Fig. 2, the lower plate of the pump casing, the treatment variant according to the third method.
    It is known that magnetohydrodynamic pumps for corrosive molten metals, in which the pump casing is made of refractory materials, are made up of a number of plates through which the pipeline for the liquid metal passes and in which various sockets for the wires of magnetic circuits are arranged. These refractory plates protect the magnetic circuits from the corrosion of molten metals and keep the magnetic circuits below the Curie point due to the low thermal conductivity of the refractory materials used.
    Thus, the casing of such a pump from the outside looks like the imposition of several plates of refractory material (Fig. 1), where the image is. SRI removed all internal parts for
    j with the exception of the vertical pipeline for liquid metal.
    Sequential plates of refractory material 1, 2, 3 and 4: form the pump casing, in which 0 parts 5, 6.7 and 8 are represented
    only channel elements for molten material.
    The bottom plate 1 is in contact with the molten metal with its 5 base and side surface.
    processed on the side and bottom surfaces.
    This plate 1 is reversed in order to better see the slits applied on these two surfaces. It is seen / that radial slots 9 are made on the base. These slots end on channel 5, where they penetrate to a certain depth.
    On the side surface of the plate 1, which is also in contact with the liquid metal, there are visible slots 10, which continue the slots 9 applied on the base. Thus, all the slits are radial.
    Plate 2 carries slots on its side surface, 11, etc. These slots are also radial. The upper and lower surfaces of this plate are not in contact with the liquid metal. Therefore, these surfaces do not have slots.
    The side slits of these two plates are rounded at their ends in order to avoid the formation of zones of sharp drops.
    According to the second method of product protection, plates made of a less dense heat-resistant material than the base material, but having the same expansion coefficient, are glued to the surface of the heat-resistant body of the product.
    FIG. 1, such plates are superimposed on plate 3. They are represented by positions 12 and are separated by grooves 13 and 14.
    Plates are made of ceramics of the same composition as the ceramics surrounding the pump, but of much lower density and possessing higher insulating properties than the ceramics of the pump casing, as well as a higher resistance to thermal shocks than the base material. The mechanical properties of these plates are lower than the mechanical properties of the ceramics supporting them, but these plates play the role of only thermal protection, so they do not need special mechanical properties. Glue for these plates is made by finely grinding a mixture of alumina and silicon fibers and then introducing an inorganic and kemetic binder to take the form of a paste or liquid. However, such sv. it is insufficiently resistant to the impact of corrosive molten metals.
    Therefore, for protection, it is necessary to fill the grooves, slots and drilling with means, impermeable to liquid metal, and easily compressible in order not to oppose the expansion of the outer, thus treated, layer of the pump casing. ,
    FIG. 2 shows the bottom plate 1 of the pump, which is treated according to the third method, which does not allow to reduce the stress after the thermal shock.
    The two surfaces that are in contact with the molten metal are the same as in the previous case (the side surface and the base, this time represented at the bottom of the plate, since it is located in its usual position). Radial drills 15 are connected to the central channel 5. These drills are then extended to the base, which is in constant contact with the molten metal, through slots 16. Thus, the slits 16 end with radial drills, which protect the plate from mechanical forces, arising from the propagation of heat from the base of the pump up.
    The side protection of the plate 1 is made as before (Fig. 1) with vertical drillings 17 parallel to the pump axis extending out through the slots 18.
    These drillings and cuts are located in plate 1 symmetrically, each drilling parallel to the axis lies in
    0
    planes of a dihedral bisector
    the angle formed by the slots 16. With the arrangement, when each slot ends with a cylindrical channel, the distribution of internal stresses is provided, such that the cracking really becomes unlikely.
    The cuts and drillings are also filled with a substance impermeable to the molten metal. It is convenient to use a known mixture of alumina and silicon fibers, made in the form of wadding or felt, which is carried out
    stuffing these slots and drillings.
    Such packing is not wetted by liquid metal. Therefore, the liquid metal does not penetrate into the slots and does not come into contact with the inner ceramic layer, and thus ensures complete protection of the pump.
    The pump casing, made with protection, was tested by abrupt immersion in molten aluminum for 60 minutes, then quickly removed 5 and cooled in an air stream for 60 minutes. This operation was repeated 50 times, without any changes in the external ceramic plug of the pump.
    权利要求:
    Claims (1)
    [1]
    1. The product, preferably the pump casing, subjected to repeated thermal shocks during
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    同族专利:
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    引用文献:
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    RU176420U1|2017-11-16|2018-01-18|Дмитрий Вадимович Пакин|3D STEP|US3242239A|1961-08-16|1966-03-22|Freeman Chemical Corp|Filling structural cavities|
    FR1578396A|1967-12-12|1969-08-14|
    US3505158A|1967-12-22|1970-04-07|Coors Porcelain Co|Composite porous-dense ceramic article|
    US3552533A|1968-10-01|1971-01-05|Abex Corp|Carbonized friction article|
    FR2052105A6|1969-07-16|1971-04-09|Alsacienne Atom|
    US3712428A|1970-06-22|1973-01-23|Carborundum Co|Reinforced carbon bodies|US4115608A|1977-11-22|1978-09-19|Glass Carl R|Ornamental sunburst hub|
    US4228210A|1978-01-30|1980-10-14|Trw Inc.|Plate or the like with serrated opening|
    US4315098A|1979-07-25|1982-02-09|Electric Power Research Institute, Inc.|Insulative spacer for a low temperature coaxial cable and coaxial cable including the same|
    FR2520701B1|1982-02-02|1985-10-25|Giepac Bourgogne Sa|PRE-CUT CARDBOARD BLANK FOR CONSTITUTING A TRAY FOR PACKAGING VARIOUS OBJECTS|
    US4692367A|1986-04-24|1987-09-08|The United States Of America As Represented By The Secretary Of The Army|Method of making a thermally stable composite honeycomb panel|
    DE9001227U1|1990-02-03|1990-04-05|H. Krantz Gmbh & Co, 5100 Aachen, De|
    KR0147672B1|1995-11-30|1998-08-01|김광호|A label of wiper easily distinguished|
    US20130260089A1|2012-03-28|2013-10-03|Refractory Specialties, Inc.|Body formed of refractory material having stress relief slits and method of forming the same|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    FR7304667A|FR2217291B1|1973-02-09|1973-02-09|
    FR7313733A|FR2244729B2|1973-04-16|1973-04-16|
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