JP6509769B2 - Wall structure of container or piping for containing or transporting high temperature gas - Google Patents

Description

  The present invention relates to the wall structure of a vessel or piping for containing or transporting a high temperature gas. A melting furnace, a melting furnace, an incinerator, a secondary combustion tower etc. can be illustrated as a container which accommodates a high temperature gas. As piping which conveys high temperature gas, the exhaust pipe of the melting furnace which melt-processes a waste material and piping which connects the melting furnace of the apparatus which melt-processes a waste and a secondary combustion tower can be illustrated.

  Conventionally, for example, an arc furnace, a plasma furnace, a resistance furnace, a burner furnace or the like is used as a melting furnace for melting and processing waste.

  A metal (iron shell) is used for the wall of a container or piping for containing or transporting high-temperature gas of a device equipped with a melting furnace or melting furnace for melting metal or waste.

  As shown in FIG. 3, the conventional wall structure is constructed in the order of iron skin 51, heat insulation board 52 in contact with iron skin 51, and fireproof castable 53 in contact with heat insulation board 52. Heat insulation board 52 and fireproof castable 53 are iron skin It is supported by a metal anchor 54 welded to 51.

  There is also known a wall structure in which a heat insulation board is attached to the inside of the iron skin to enhance the heat insulation of the container and piping, and a fireproof castable is installed on the inside of the heat insulation board and supported by anchors. Reference 1.).

JP 9-318275 A

  The anchor is usually made of metal and attached by welding to the iron skin. When the refractory castable is exposed to high temperature gas (direct contact with high temperature gas), it is likely to crack or the like. The gas penetrates the fireproof castable from a crack or the like, passes through the pores of the heat insulating board, and is exposed to the gas from the tip of the anchor to the root (welded portion between the anchor and the iron skin). The anchor and the iron shell are corroded by the gas and the supporting power is reduced. In particular, welds are susceptible to corrosion and fireproof castables may fall off with each anchor.

  The anchor may be made of ceramic and screwed to the iron skin, but even in this case, the gas that has penetrated and reached the iron skin may corrode the screw hole of the iron skin, and the fireproof castable may fall off with each anchor. .

  Increasing the thickness of the insulation board and fireproof castables attached to the inside of the shell can reduce gas penetration, but reduces the volume of the container and the inner diameter of the piping.

  The present invention has been made in view of the above problems, and it is an object of the present invention to provide a wall structure in which the penetration of gas into the joint between the anchor and the skin is suppressed without reducing the volume or the inner diameter. It will be an issue.

The wall structure according to the present invention made to solve the problem is a wall structure supported by an anchor of a container or piping which accommodates or transports high temperature gas, and the wall in contact with the high temperature gas is from the outside to the inside. The iron shell, the outer refractory castable in contact with the iron shell, the heat insulating layer in contact with the outer refractory castable, and the inner fireproof castable in contact with the heat insulating layer are constructed in this order ; It is characterized in that it consists of either .

  Since the outer refractory castable is not exposed to the high temperature gas, it is unlikely to crack. Therefore, the penetration of the gas that has passed through the pores of the heat insulating layer and reached the outer refractory castable into the joint between the anchor and the iron skin is suppressed.

  In the above-mentioned wall structure, the apparent porosity of the outer refractory castable may be lower than the apparent porosity of the heat insulating layer.

  The gas that has passed through the pores of the heat insulating layer and reached the outer refractory castable is further suppressed from entering the joint between the anchor and the iron skin.

  The outer refractory castable does not come into contact with the high temperature gas, so cracking is less likely to occur. Therefore, the gas that has passed through the pores of the fireproof insulation and reaches the outer refractory castable is inhibited from intruding into the joint between the anchor and the iron skin.

It is a longitudinal cross-sectional view of a melting furnace provided with the wall structure which concerns on Embodiment 1 of this invention. It is a longitudinal cross-sectional view of the exhaust pipe of the melting furnace of FIG. 1 provided with the wall structure which concerns on Embodiment 2 of this invention. It is sectional drawing which shows the conventional wall structure.

  The wall structure according to the embodiment of the present invention will be specifically described below.

(Embodiment 1)
The wall structure of the present embodiment is applied to the furnace wall portion in contact with the gas of the melting furnace that melts and processes waste.

  FIG. 1 is a longitudinal sectional view of a melting furnace provided with the wall structure of the present embodiment. The illustrated melting furnace is an arc furnace, and the arc furnace includes a furnace body 11, a furnace lid 12 attached to the furnace body 11, and an electrode 13 inserted into the furnace from the furnace lid 12. In the furnace, a molten metal layer 22 in the lower layer and a molten slag layer 23 in the upper layer are formed as the melt 21 generated by the melting treatment of waste, and unmelted waste is formed on the upper portion of the molten slag layer 23 There are 24. The furnace space above the molten slag layer 23 is filled with the gas 25 generated by the melting treatment of waste. Connected to the furnace lid 12 is an exhaust pipe 14 for transporting the gas 25 to a secondary combustion tower, a dust collector, and the like.

  The furnace wall portion (upper side wall of the furnace main body 11) in contact with the gas 25 is an iron shell 31, an outer refractory castable 41 in contact with the iron shell 31, and a heat insulation board 42 in contact with the outer refractory castable 41 The inner refractory castable 43, the heat insulating board 42 and the outer refractory castable 41 are supported by an iron anchor 44 welded to the iron shell 31.

  As described above, in the furnace wall structure supported by the anchor 44 exposed to the high temperature gas of the present embodiment, the outer refractory castable 41 is interposed between the iron skin 31 and the heat insulation board 42. Since the outer refractory castable 41 is not exposed to the high temperature gas, the occurrence of cracking is suppressed. As a result, the gas that has passed through the pores of the heat insulating board 42 and reached the outer refractory castable 41 is prevented from entering the joint between the anchor 44 and the iron shell 31.

  As the heat insulation board 42, for example, a plate made of a siliceous powder, slaked lime, ceramic fiber or the like as a main raw material and formed into a plate shape can be used.

  Moreover, the heat insulation board 42 should just be a heat insulation layer, and heat insulation bricks and heat insulation castables can also be used.

  Thereby, the penetration of the gas that has passed through the pores of the heat insulating board 42 and reached the outer refractory castable 41 into the joint between the anchor 44 and the iron skin 31 is further suppressed.

Second Embodiment
The wall structure of the present embodiment is applied to the exhaust pipe of a melting furnace that melts and processes waste.

  FIG. 2 is a longitudinal sectional view of the exhaust pipe (the exhaust pipe 14 of FIG. 1) provided with the wall structure of the present embodiment. The tube wall portion includes an iron shell 141, an outer fireproof castable 142 in contact with the iron skin 141, an insulation board 143 in contact with the outer fireproof castable 142, and an inner fireproof castable 144 in contact with the insulation board 143 The inner fireproof castable 144, the heat insulation board 143 and the outer fireproof castable 142 are supported by an iron anchor 145 welded to the iron shell 141.

  The thickness of the heat insulation board 52 when the exhaust pipe 14 provided with the wall structure of this embodiment is the conventional wall structure from the viewpoint of heat insulation and heat resistance is tdr, and the thickness of the fireproof castable 53 is tcr (Fig. 3). The thickness td of the heat insulation board 143 of the exhaust pipe 14 having the wall structure of the present embodiment is equal to tdr from the viewpoint of heat insulation. Further, a thickness obtained by adding the thickness tco of the outer refractory castable 142 to the thickness tci of the inner refractory castable 144 of the exhaust pipe 14 having the wall structure of the present embodiment is the thickness tcr of the refractory castable 53 from the viewpoint of heat resistance. Is equal to That is, since the total thickness of the wall is not increased from the viewpoint of heat insulation and heat resistance, the inner diameter of the exhaust pipe 14 does not decrease.

  If the iron anchor 145 of this embodiment is made of ceramic (for example, silicon nitride or silicon carbide), the anchor 145 itself is not corroded by gas, but the screw hole of the iron shell 141 for screwing the anchor 145. When the gas penetrates, the portion may be corroded and the anchor 145 may come off. However, in the wall structure of the exhaust pipe 14 of the present embodiment, since the outer refractory castable 142 is interposed between the heat insulation board 143 and the iron shell 141, the invasion of gas to the screw hole of the iron shell 141 is suppressed Be done.

31,141 ...... iron skin 41,142 ...... outside the refractory castable 42,143 ...... insulation board 43,144 ...... inside the refractory castable 44,145 - ·····anchor

Claims (2)

A wall structure supported by a container for containing a high temperature gas or an anchor of a pipe for conveying a high temperature gas, the wall structure comprising:
Wall in contact with hot gases from the outside to the inside furnace shell, outer refractory castable in contact with the iron skin, the heat insulating layer in contact with the outer refractory castable, will be constructed in the order of the inner refractory castable in contact with the heat insulating layer ,
The wall layer structure of a vessel or piping , wherein the heat insulating layer is made of either a heat insulating board or a heat insulating brick .   The wall structure of a vessel or pipe according to claim 1, wherein an apparent porosity of the outer refractory castable is lower than an apparent porosity of the heat insulating layer.

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