JP2006300410A - Ash melting furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ash melting furnace prevented from erosion, seepage, or the like of a hearth structure such as firebricks or a monolithic refractory in a short period of time in melting ashes under actual circumstances where the variation of composition of the ashes to be melted cannot be predicted. <P>SOLUTION: The ash melting furnace with electrodes inserted in the furnace and with the firebricks laid in inverted arch shape as a whole on the hearth through the monolithic refractory, is constituted to melt the ashes charged in the furnace by applying a current to the electrodes, wherein the monolithic refractory of completely different material from the firebricks is placed further on the upper face of the firebricks laid in inverted arch shape as a whole on the hearth. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ash melting furnace. When municipal waste or industrial waste is incinerated, ash such as incineration ash and fly ash is generated. Such ash is melted using an ash melting furnace in order to reduce the volume and make it harmless. The present invention relates to an improvement of such an ash melting furnace.

Conventionally, as an ash melting furnace as described above, an electrode is inserted in the furnace, and the refractory bricks are laid in a reverse arch shape as a whole on the hearth via an indeterminate refractory and charged into the furnace. What melt | dissolved the ash by supplying with electricity to this electrode is known (for example, refer patent document 1). In such a conventional ash melting furnace, an Al ₂ O ₃ -based material containing Al ₂ O ₃ as a main material and containing SiC, for example, Al ₂ O ₃ − it is preferred to use those of SiC-based or _Al 2 _O 3 -SiC-C system, also those of _Al 2 _{O 3} system to further composed primarily Similarly the _Al 2 _{O 3} surface of such refractory bricks, for example Al ₂ It has also been proposed that it is preferable to protect with an O ₃ —Cr ₂ O ₃ -based or Al ₂ O ₃ —SiO ₂ -based amorphous refractory.

However, in the conventional ash melting furnace as described above, there is little erosion or infiltration of the refractory bricks usually laid on the hearth or the amorphous refractory for protecting the ash melting process. It is speculated that this is due to fluctuations in the composition of ash due to its origin, but sometimes refractory bricks laid on the hearth and irregular refractories to protect this erode or infiltrate in a short period of time. There is a problem that it may occur.
Japanese Patent Laid-Open No. 5-118522

  The problem to be solved by the present invention is presumed to be attributable to its origin, but when the ash is melt-treated under the circumstances where fluctuations in the composition of the ash that is the subject of the melt treatment cannot be predicted, The present invention is to provide an ash melting furnace that can prevent a hearth structure such as a brick or an irregular refractory from being eroded or infiltrated in a short time.

  The present invention that solves the above-mentioned problem is that an ash is inserted in the furnace, with electrodes inserted in the furnace, and refractory bricks are laid in a reverse arch shape as a whole on the hearth via an irregular refractory. In an ash melting furnace which is melted by energizing the electrode, an amorphous refractory made of a material completely different from the refractory brick is further provided on the upper surface of the refractory brick laid in a reverse arch shape on the hearth as a whole. The present invention relates to an ash melting furnace.

  Also in the ash melting furnace according to the present invention, an electrode is inserted in the furnace, and refractory bricks are laid in a reverse arch shape as a whole on the hearth via an irregular refractory, and the ash charged into the furnace is removed. Melting is performed by energizing the electrode. Therefore, the ash melting furnace according to the present invention is a so-called electric furnace, and examples of such an electric furnace include a resistance furnace, an arc furnace, a plasma arc furnace, and a plasma furnace, and an arc furnace or a plasma arc furnace is preferable.

In the ash melting furnace according to the present invention, an amorphous refractory made of a material completely different from the refractory brick is placed on the upper surface of the refractory brick laid in a reverse arch shape as a whole on the hearth. Here, a completely different material is at least the main material between a refractory brick laid on the hearth in a reverse arch shape as a whole and an irregular refractory placed on the upper surface of the refractory brick. Means different. For example, as a refractory brick laid in a reverse arch shape as a whole on the hearth, an Al ₂ O ₃ based material containing Al ₂ O ₃ as a main material and containing SiC, more specifically an Al ₂ O ₃ —SiC based material When an Al ₂ O ₃ —SiC—C-based material is used, an amorphous refractory placed on the upper surface of the refractory brick is similarly used as an oxide-based material mainly composed of Al ₂ O ₃ . Rather than using an Al ₂ O ₃ —Cr ₂ O ₃ type or Al ₂ O ₃ —SiO ₂ type, MgO—Al ₂ O ₃ type or MgO— containing MgO as the main material A Cr ₂ O ₃ -based material is used. The main material is the same as Al ₂ O ₃ described above between the refractory brick laid in a reverse arch shape as a whole on the hearth and the irregular refractory placed on the upper surface of the refractory brick. If this is the case, the refractory bricks and irregular refractories for the same reason are subject to erosion, infiltration, etc. in a short period of time, making it impossible to cope with unpredictable variations in ash composition.

  In the ash melting furnace according to the present invention, as described above, refractory bricks are laid in a reverse arch shape as a whole on the hearth, and the refractory bricks are made of a material that is completely different from the refractory bricks on the upper surface of the refractory bricks. Refractories are placed. In place of such an irregular refractory, it is conceivable that a refractory brick is separately laid, so that it is possible to stack refractory bricks of completely different materials in the upper and lower two stages, but in this way, according to the present invention as described above. Compared to ash melting furnaces, not only is it uneconomical, but repair and replacement of these refractory bricks become extremely troublesome.

  According to the ash melting furnace according to the present invention, when the ash is melt-processed under a situation where fluctuations in the composition of the ash to be melt-processed cannot be predicted, a hearth structure such as a refractory brick or an amorphous refractory is provided. It is possible to prevent erosion or infiltration in a short time.

FIG. 1 is a longitudinal sectional view illustrating an ash melting furnace according to the present invention. Here, the case of a three-phase AC arc furnace is illustrated. A furnace lid 2 is attached to the top of the furnace body 1 so as to be openable and closable, and an electrode 3 is inserted into the furnace through the furnace lid 2. An indeterminate refractory 5 is placed on the hearth 4 of the furnace shell 4 of the furnace body 1, and the upper surface of the indeterminate refractory 5 is formed in a reverse arch shape as a whole. A refractory brick 6 is laid on the upper surface of the irregular refractory 5, and thus the refractory brick 6 has a reverse arch shape as a whole. On the upper surface of the refractory brick 6, an irregular refractory 7 made of a material different from that of the refractory brick 6 is placed. Therefore, the irregular refractory 7 is also formed in a reverse arch shape as a whole. In the ash melting furnace illustrated in FIG. 1, the refractory brick 6 uses an Al ₂ O ₃ —SiC-based refractory 7 containing 55% by mass of Al ₂ O ₃ and 35% by mass of SiC. Uses an MgO-based material containing 94% by mass of MgO.

  Although the refractory bricks 8 and 9 are lined on the furnace wall of the furnace shell 4, illustration is omitted, but the furnace lid 2 has an ash inlet and an exhaust outlet, and the furnace body 1 has a molten slag outlet. Etc. are provided. In the case of the illustrated ash melting furnace, the ash charged into the furnace is melted by an arc generated by energizing the electrode 3, and the molten metal layer A generated by the melting process is contained in the furnace. And a molten slag layer B are formed.

The longitudinal cross-sectional view which illustrates the ash melting furnace which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Furnace body 2 Furnace lid 3 Electrode 4 Furnace shell 5,7 Amorphous refractory 6,8,9 Refractory brick A Molten metal layer B Molten slag layer

Claims (2)

  An electrode is inserted in the furnace, and the refractory bricks are laid in a reverse arch shape as a whole via an irregular refractory on the hearth, and the ash charged into the furnace is melted by energizing the electrode. In the ash melting furnace constructed as described above, the refractory brick laid in a reverse arch shape as a whole on the hearth is further provided with an indeterminate refractory made of a material completely different from the refractory brick. Ash melting furnace. Is of Al ₂ O ₃ system refractory bricks laid in reverse arch shape as a whole in the hearth and containing SiC as a main material an Al ₂ O _3, not being Da設further the upper surface of the refractory bricks 2. The ash melting furnace according to claim 1, wherein the regular refractory is an MgO-based material mainly composed of MgO.

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