JP2006329619A - Ash supply method to burner type ash fusion furnace, and burner type ash fusion facility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply ash mixed with plastic pieces to an ash fusion furnace to be burnt satisfactorily, and to attain a low fuel consumption. <P>SOLUTION: The ash mixed with waste plastics is fed from an ash feed chute 12 into an ash hopper 13, the ash mixed with the waste plastics is fed respectively toward feeding-directional both side walls 13a of a pusher main body 14a, from the ash feed chute 12 into the ash hopper 13, when supplied to the ash fusion furnace by the pusher main body 14a advancing and retreating from a bottom opening of the ash hopper 13 into/from a supply passage, and a distribution of the waste plastics is thereby concentrated in the central part of the ash hopper 13, using differences between particle sizes and repose angles of the ash and the waste plastics. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for supplying ash to a burner-type ash melting furnace and a burner-type ash melting facility for reducing the volume of incinerated ash and fly ash and making them harmless.

The incineration ash and fly ash discharged from the waste incinerator have a large capacity and contain harmful substances. Therefore, for the purpose of volume reduction and detoxification, the molten slag is heated and melted to produce molten slag, and asphalt slag It is reused as aggregate or used for landfill. Examples of the melting heat source of the ash melting furnace include a burner and plasma described in Patent Document 1.
Japanese Patent Laid-Open No. 6-147452

  In the burner type ash melting furnace using a burner as a melting heat source as in the cited document 1, since the heat generation amount of ash is low, there is a problem that a large amount of fuel is required for the burner, and improvement of fuel consumption has been demanded.

  An object of the present invention is to solve the above problems and provide an ash supply method and a burner ash melting facility for a burner ash melting furnace capable of realizing low fuel consumption.

  The method for supplying ash to the burner type ash melting furnace according to claim 1 is characterized in that ash mixed with waste plastic is supplied from an ash input chute to an ash hopper, and is pushed by a pusher that exits the supply passage from the bottom opening of the ash hopper. When supplying the ash melting furnace, the ash from the ash charging chute is fed into the ash hopper into the ash hopper toward the side walls on both sides in the pusher delivery direction, thereby distributing the waste plastic to the center of the ash hopper. Concentrate.

  The burner-type ash melting facility according to claim 2 inputs ash mixed with waste plastic from an ash charging chute into an ash hopper, and supplies the ash melting furnace with a pusher that exits and exits a supply passage from the bottom opening of the ash hopper. In the burner type ash melting facility, the ash charging chute is opened so as to be charged toward the side walls on both sides in the pusher feed direction above the ash hopper.

  The burner-type ash melting facility according to claim 3 inputs ash mixed with waste plastic from an ash charging chute into an ash hopper, and supplies the ash melting furnace with a pusher that exits and exits a supply passage from the bottom opening of the ash hopper. In the burner type ash melting facility, a waste plastic supply line that mixes waste plastic is connected to an ash supply line that supplies ash to the ash charging chute, and a pulverizer that pulverizes the waste plastic to the waste plastic supply line, The ash charging chute is placed on both sides of the pusher delivery direction above the ash hopper via a pressure reducing machine that compresses and reduces the volume of the pulverized waste plastic to an apparent specific gravity of 0.35 or more. It opened so that it might each inject | pour toward the side wall.

  As described above, according to the first or second aspect of the present invention, ash is accumulated on both sides of the ash hopper at the center of the charging direction, and the waste plastic is ash. Rolls down into the recess at the center of the hopper and concentrates on the distribution. For this reason, waste plastic gathers in the center part at the time of extrusion by a pusher, and waste plastic which contacts the side wall of a supply passage can be reduced very much. Therefore, the waste plastic melts and adheres due to the heat of the side wall, solidifies or carbonizes and does not fall out of supply, and the waste plastic is in good contact with air in the center of the furnace, so incomplete combustion Thus, neither CO nor DXN is generated.

  According to the invention described in claim 3, since the amount of heat generated can be increased by the waste plastic, the fuel consumption of the burner can be reduced, and the combustion speed is reduced by the waste plastic whose volume has been reduced after pulverization. As a result, combustion fluctuations associated with fluctuations in the supply amount of ash can be reduced, and efficient and stable low air ratio combustion is possible even at a mixing ratio of 16% by weight. In addition, due to the difference in the angle of repose of ash and waste plastic, ash accumulates on both sides, and the waste plastic rolls down to the central recess and is concentrated. For this reason, waste plastic gathers in the center part at the time of extrusion by a pusher, and waste plastic which contacts the side wall of a supply passage can be reduced very much. Therefore, the waste plastic does not melt and adhere due to the heat of the side wall of the supply passage, solidifies or carbonizes and cannot be supplied, and the waste plastic is in good contact with the air in the center of the furnace. There is no combustion and no generation of CO or DXN.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Embodiment 1]
Embodiment 1 of the burner type ash melting facility according to the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the burner type ash melting facility includes a burner type ash melting furnace 1, an ash supply device 2, an ash supply line 3 that supplies ash A composed of incinerated ash and fly ash to the ash supply device 2, and The ash supply line 3 is provided with a waste plastic supply line 4 for mixing the waste plastic P.

  The ash melting furnace 1 is provided with a preheating chamber 6 on the upstream side of the inclined bottom wall 5 and a melting chamber 7 on the downstream side, and preheats the exhaust gas from the melting burner 8 provided at the top of the melting chamber 7. The ash A is introduced into the chamber 6 and discharged to the exhaust duct 9 to preheat the ash A supplied from the preheating chamber 6.

  The ash supply device 2 supplies ash A mixed with waste plastic P from the ash input chute 12 to the ash hopper 13 and supplies the ash hopper 13 from the bottom opening of the ash hopper 13 to the preheating chamber 6 by the pusher device 14. The pusher device 14 includes a pusher body 14a that is detachably disposed in a supply passage 15 connected to the preheating chamber 6 side from the bottom opening of the ash hopper 13, and a push cylinder 14b that drives the pusher body 14a to move in and out. It consists of As shown in FIG. 2, the ash charging chute 12 is branched in an inverted V shape from the center portion to form openings 12 a, 12 a toward the left and right side walls 13 a of the ash hopper 13, and the ash of waste plastic P mixed. It is configured so that A is thrown toward the left and right side walls 13a, 13a of the ash hopper 13 and accumulated, so that the waste plastic P with a small angle of repose rolls from the vicinity of the top of the ash A near the side wall 13a when thrown. It can fall and collect in the center part of the ash hopper 13 used as a recessed shape. Here, instead of the ash charging chute 12 branched in an inverted V shape, chutes may be arranged on both sides.

  Here, an introduction experiment of the ash A mixed with the waste plastic P will be described. That is, as shown in FIG. 4A, ash A mixed with waste plastic P was dropped from a 350 mm × 300 mm square duct 31 and dropped onto a tray 32 500 mm below. As a result, as shown in FIG. 4 (b), the ash A was deposited in a mountain shape at the central portion, whereas the waste plastic P was rolled down and concentrated on the skirt portion. This is because the waste plastic P tends to slide down and its distribution concentrates on the periphery of the tray 32 due to the difference in the particle size and angle of repose of the ash A and the waste plastic P. When the waste plastic P is concentrated on the periphery of the ash hopper 13, it is pushed out from the bottom by the pusher body 14a along the side wall 15a to the preheating chamber 6, and the waste plastic P is melted by the heat of the heated side wall 15a. There was a risk that it could not be supplied due to solidification or carbonization. Furthermore, the waste plastic P supplied to the corner portion of the melting chamber 6 along the side wall 15a has poor contact with the air in the furnace, and may be incompletely burned to cause CO and DXN.

  Next, as shown in FIG. 4 (a), a plate 33 is erected on one side of the tray 32, and a guide tube 31 a that is inclined toward the plate 33 is provided at a lower portion of the rectangular duct 31. The ash A mixed with the waste plastic P was dropped toward the plate 33 through the cylinder 31a, and dropped onto the tray 32 550 mm below along the plate 33. In this case, as shown in FIG. 4B, the ash A accumulated in a mountain shape on the plate 33 side, and a large amount of waste plastic P was distributed on the bottom side opposite to the plate 33.

  From the above experimental results, it was found that the distribution of the waste plastic P in the dropped state of the ash A mixed with the waste plastic P is concentrated in the periphery of the dropping position. Therefore, in this embodiment, when the ash A mixed with the waste plastic P is dropped toward the left and right side walls 13 a of the ash hopper 13, the ash A accumulates on the left and right side walls 13 a of the ash hopper 13. Waste plastic P is concentrated and distributed in the central part. As a result, the ash A mixed with the waste plastic P pushed out by the pusher main body 14a is distributed in a concentrated manner in the central portion, and the waste coming into contact with the side wall 15a of the supply passage 15 to be heated. Plastic P is very little. And it does not adhere and solidify to the side wall 15a or the side wall of the melting furnace 1. In addition, since the waste plastic P is burned in contact with sufficient air in the central portion of the preheating chamber 6, it does not burn incompletely, and the generation of CO and DXN can be prevented.

  The ash supply line 3 is used to dry and supply the ash A discharged from the incinerator in a fixed amount, and a waste plastic supply line 4 is connected to the downstream side to mix a predetermined amount of waste plastic P. In the waste plastic supply line 4, a pulverizer 21 for pulverizing the waste plastic P is interposed on the upstream side, and a pressure reducing machine 22 is interposed on the downstream side.

  By the way, when this waste plastic is pulverized by the pulverizer 21, the apparent specific gravity of the waste plastic is 0.1, the apparent specific gravity (bulk specific gravity) of the ash is lower than 1.0, and the amount of the waste plastic is small by volume ratio. Become more. In addition, the pulverized product has a non-uniform shape and weight, and the combustion rate is not constant, and combustion fluctuations are likely to occur due to fluctuations in the ash supply amount, making stable low air ratio combustion difficult. For this reason, there is a problem that stable operation cannot be achieved with a mixing ratio of waste plastics having a weight ratio of 10% or more.

  However, the pulverized waste plastic P can be pressurized and compressed by the pressurization and volume reducer 22 to make the apparent specific gravity 0.35 or more with a particle size of about 15 mmφ. In addition, when the mixing ratio exceeds 10% by weight, ordinary plastic waste plastic P that is only pulverized cannot be mixed more than 10% because combustion becomes unstable. In addition, by increasing the apparent specific gravity to 0.35 or more, the burning rate of the waste plastic P can be reduced and averaged, so even if the mixing ratio is increased to about 16% by weight, stable efficiency is high. Low air ratio combustion is possible, and the fuel consumption of the melting burner 8 can be improved by increasing the calorific value, thereby enabling stable melting.

Table 1 below shows the waste plastic mixing ratio and the O ₂ concentration in the exhaust gas in the experiment when the ash melting amount is 200 kg / h. According to Table 1, it can be seen that even when the mixing ratio of the waste plastic P according to the present invention is 16%, the O ₂ concentration in the exhaust gas is low and the combustion is sufficiently performed.

上記実施の形態によれば、廃プラスチックＰを灰Ａに混合することにより、発熱量を上げて溶融バーナー８の燃料の消費を低減することができる。また廃プラスチックＰが粉砕機２１により粉砕された後、加圧減容機２２により見掛け比重が０．１から０．３５以上に圧縮されることから、粒径の均一化と燃焼速度の減速が図れ、混合率を重量比で１６％程度に上げても安定した低空気比燃焼が可能となる。

According to the above embodiment, by mixing the waste plastic P with the ash A, the calorific value can be increased and the fuel consumption of the molten burner 8 can be reduced. In addition, after the waste plastic P is pulverized by the pulverizer 21, the apparent specific gravity is compressed from 0.1 to 0.35 or more by the pressure-reducing unit 22, so that the particle size is uniformized and the combustion speed is reduced. As a result, even if the mixing ratio is increased to about 16% by weight, stable low air ratio combustion is possible.

  Further, since the charging chute 12 is branched and the ash A mixed with the waste plastic P is introduced toward the left and right side walls 13 a of the ash hopper 13, the waste plastic P is concentrated on the central portion of the ash hopper 13. Can be distributed. Thereby, when the pusher body 14a is pushed in, the waste plastic P hardly comes into contact with the side wall 15a of the supply passage 15, and a failure such as a blockage due to the solidification of the waste plastic P can be prevented. In addition, since most of the waste plastic P is sent out to the central portion of the preheating chamber 6, it can be sufficiently brought into contact with air and can be completely burned, and the generation of CO and DXN due to incomplete combustion can be prevented. .

It is a lineblock diagram showing an embodiment of a burner type ash melting furnace concerning the present invention. It is II sectional drawing shown in FIG. (A) And (b) shows the dropping distribution experiment of the mixed ash of a waste plastic, (a) is a layout, (b) is a perspective view which shows a distribution state. (A) And (b) shows the dropping distribution experiment of the mixed ash of a waste plastic, (a) is a layout, (b) is a perspective view which shows a distribution state.

Explanation of symbols

A ash (incineration ash + fly ash)
P Waste plastic 1 Ash melting furnace 2 Ash supply device 3 Ash supply line 4 Waste plastic supply line 6 Preheating chamber 7 Melting chamber 8 Melting burner 12 Ash charging chute 12a Opening 13 Ash hopper 13a Side wall 14 Pusher device 14a Pusher body 15 Supply passage 21 Crusher 22 Pressure reduction machine

Claims (3)

When charging the ash mixed with waste plastic from the ash charging chute into the ash hopper and supplying it to the ash melting furnace with a pusher that exits and exits the supply passage from the bottom opening of the ash hopper,
A burner characterized in that the distribution of waste plastic is concentrated in the center of the ash hopper by charging the ash from the ash charging chute into the ash hopper toward the side walls on both sides in the pusher feed direction. Ash supply method to the ash melting furnace. In the burner-type ash melting facility, the ash mixed with waste plastic is charged into the ash hopper from the ash charging chute, and the ash melting furnace is supplied to the ash melting furnace by a pusher that exits and exits the supply passage from the bottom opening of the ash hopper.
A burner-type ash melting facility, wherein the ash charging chute is opened so as to be charged toward the side walls on both sides in the pusher delivery direction above the ash hopper. In the burner-type ash melting facility, the ash mixed with waste plastic is charged into the ash hopper from the ash charging chute, and the ash melting furnace is supplied to the ash melting furnace by a pusher that exits and exits the supply passage from the bottom opening of the ash hopper.
Connect the waste plastic supply line that mixes waste plastic to the ash supply line that supplies ash to the ash input chute,
In this waste plastic supply line, a pulverizer for pulverizing the waste plastic and a pressure reducing machine for compressing and reducing the volume of the pulverized waste plastic so that the apparent specific gravity is 0.35 or more are interposed,
A burner-type ash melting facility, wherein the ash charging chute is opened so as to be charged toward the side walls on both sides in the pusher delivery direction above the ash hopper.

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