JP2005241202A - Ash melting facility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide ash melting facility capable of melting ashes smoothly by preventing adhesion of chlorine compound to an inner face of a flue through which exhaust gas is fed out, improving quality of molten slag, and prolonging service life of the facility. <P>SOLUTION: This ash melting facility 1 has an ash melting furnace 10 for melting ashes X charged into a furnace body 12 through an ash charging port 15 to generate molten slag S and the flue 21 whose one end 21a is connected with the ash melting furnace 10 to lead exhaust gas G generated in the furnace body 12. The flue 21 is provided by tilting downward toward the other end 21b from one end 21a connected with the ash melting furnace 10. It is provided with a heating part 22 for heating exhaust gas G fed in from the furnace body 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ash melting facility for melting and treating ash generated when incineration of municipal waste, industrial waste, and other incineration products.

In recent years, ash melting using an ash melting facility equipped with an ash melting furnace has become widespread from the viewpoint of decomposition of dioxins contained in incineration ash of waste. As an ash melting furnace, a DC electric resistance type is known (for example, see Patent Document 1).
This DC electric resistance type ash melting furnace has a furnace body into which ash is introduced from an ash inlet, a main electrode disposed in the furnace body, and a furnace bottom electrode provided at the furnace bottom. . In this ash melting furnace, the ash in the furnace body is sequentially melted by Joule heat by the current flowing between the main electrode and the furnace bottom electrode to form molten slag. Then, the molten slag in the furnace body is taken out from the molten slag discharge port on the side of the furnace body, and the molten exhaust gas generated in the furnace body is exhausted from the exhaust gas port in the upper part of the furnace body.
JP 2000-274649 A

By the way, the chlorine compound contained in the ash charged into the furnace body has a low melting point (for example, softening at about 300 ° C., melting point 650 ° C.) and boiling point (for example, about 1100 ° C.). On the other hand, since the inside of the ash melting furnace becomes a high temperature of 1200 ° C. or higher, the chlorine compound in the ash is volatilized in the furnace to be in a gaseous state and exhausted from the exhaust gas outlet.
However, when the chlorine compound is discharged from the exhaust port, the temperature decreases, and as the temperature decreases, it changes to liquid and solid, adheres to the inner surface of the flue connected to the exhaust port, and blocks the flue. There was a risk of causing it.
For this reason, it is conceivable to use a device that mechanically scrapes the chlorine compound adhering to the inner surface of the flue or a device that blows it away with gas. In this case, the obstruction made of the chlorine compound removed from the inner surface of the flue It is returned to the body, causing the circulation and concentration of chlorine compounds in the system to be accelerated. As a result, a short path to the molten salt layer on the molten slag with a charged current causes problems in ash melting by the main electrode and the furnace bottom electrode, causes deterioration of the quality of the molten slag, and further Deterioration of the heat-resistant material will shorten the life of the equipment.

  The present invention has been made in view of the above circumstances, and prevents adhesion of chlorine compounds to the flue inner surface where exhaust gas is sent out, enabling smooth ash melting, improving the quality of molten slag, The purpose is to provide an ash melting facility capable of extending the life of the ash.

The ash melting furnace equipment according to the present invention employs the following means in order to solve the above problems.
The present invention relates to an ash melting furnace that melts ash charged into the furnace body from an ash charging port to form molten slag, and a flue that is connected to one end of the ash melting furnace and guides the exhaust gas generated in the furnace body The flue is installed so as to be inclined downward from one end to the other end connected to the ash melting furnace, and heats the exhaust gas fed from the furnace body A heating unit is provided.

In this way, the flue connected to the furnace body in order to guide the exhaust gas generated in the furnace body of the ash melting furnace is inclined downward, and further includes a heating unit for heating the exhaust gas sent from the furnace body Therefore, the chlorine compound in the exhaust gas sent to the flue is surely sent out from the ash melting furnace along the inclined flue in a liquid state without being solidified by being heated by the heating unit.
Therefore, the chlorine compound is liquefied, and the fluidity becomes poor and the adhesive state becomes soft and sticks to the inner surface of the flue. This can be prevented and contribute to stable operation.
Further, the backflow of the chlorine compound into the furnace body is reliably prevented, and the promotion of circulation and concentration of the chlorine compound in the system is avoided. As a result, the deterioration of the heat-resistant material due to the concentration of the chlorine compound is avoided and the life is prolonged. Furthermore, smooth and stable ash melting is possible, the input power is effectively used for ash melting, and the quality of the molten slag is improved.

Moreover, the said heating part is a burner provided in the said flue, It is characterized by the above-mentioned.
Thereby, the chlorine compound which falls in temperature when passing through the flue is reliably maintained in a liquid state without being heated and solidified by the burner.

Furthermore, the heating unit is the ash melting furnace that melts ash to form molten slag.
Thereby, the chlorine compound which falls in temperature when passing through the flue is reliably maintained in a liquid state without being heated and solidified by heat from the ash melting furnace.

Moreover, the said heating part makes exhaust gas 700 degreeC-1100 degreeC, It is characterized by the above-mentioned.
Thus, by making exhaust gas 700 to 1100 degreeC, a chlorine compound will be reliably made into a liquid state, and will be flowed along a flue.

Further, the flue has an inclination angle of 45 ° or more with respect to the horizontal.
Thereby, the chlorine compound in a liquid state is surely flowed downstream along the flue to prevent backflow into the furnace body.

Further, the other end of the flue is connected to a discharge part for discharging a chlorine compound contained in the exhaust gas.
As a result, the liquid chlorine compound flowing through the flue is reliably discharged and recovered.

According to the ash melting facility of the present invention, the flue connected to the furnace body for inducing the exhaust gas generated in the furnace body of the ash melting furnace is inclined downward, and the exhaust gas fed from the furnace body is further reduced. Because it has a heating section to heat, by raising the temperature of the chlorine compounds in the exhaust gas sent to the flue by the heating section, in a liquid state without solidification, the ash is surely ensured along the inclined flue It can be sent out from the melting furnace.
Therefore, the chlorine compound is liquefied, and the fluidity becomes poor and adheres to a softened state, which adheres to the inner surface of the flue and then solidifies, so that the flue channel is blocked. It can prevent and contribute to stable operation.
Further, the backflow of the chlorine compound into the furnace can be reliably prevented, and the promotion of circulation and concentration of the chlorine compound in the system is avoided. Thereby, it is possible to avoid the deterioration of the heat-resistant material due to the concentration of the chlorine compound, and to extend the life. Furthermore, smooth and stable ash melting is possible, the input power can be used effectively for ash melting, and the quality of the molten slag can be improved.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram illustrating a configuration of an ash melting facility 1 according to the present embodiment.
As shown in FIG. 1, the ash melting furnace 10 constituting the ash melting facility 1 includes a cylindrical furnace body 12 having a furnace bottom 11 and a furnace lid 13 that covers the top of the furnace body 12. . The furnace body 12 has a main electrode 14 made of a graphite electrode in the furnace body 12, and the main electrode 14 is supported by the furnace lid 13 so as to be movable up and down.

An ash charging port 15 is formed in the furnace lid 13, and ash fed from the ash supply unit 16 is charged into the furnace body 12 from the ash charging port 15.
The furnace bottom 11 includes a furnace bottom electrode 17, and the ash X introduced into the furnace body 12 is caused by Joule heat by flowing a current between the main electrode 14 and the furnace bottom electrode 17 by the DC power source 20. The molten slag S is melted sequentially.

A molten slag discharge port 18 is formed in the side wall of the furnace body 12, and the molten slag S in the furnace body 12 is taken out from the molten slag discharge port 18.
Further, an exhaust gas port 19 is formed at a side portion of the upper portion of the furnace body 12. The exhaust port 19 is connected to one end 21a of a flue 21 inclined downward. Exhaust gas G generated in the furnace body 12 is fed into the flue 21 through the exhaust port 19.

  Here, the inclination angle of the flue 21 is 45 ° or more with respect to the horizontal. Further, a burner (heating unit) 22 is provided in the flue 21. This burner 22 injects a flame into the flue 21, heats the exhaust gas G sent from the furnace body 12 to the flue 21 to 700 ° C. to 1100 ° C., and the chlorine compound Z contained in the exhaust gas G is in a liquid state To maintain.

  The other end 21 b of the flue 21 is connected to a discharge device (discharge unit) 23. The discharge device 23 has a cut gate 24 that opens and closes the opening at the bottom thereof. And this discharge device 23 sends the liquid chlorine compound Z sent from the flue 21 to the melt receiving container 25 installed below by opening the opening of the bottom part by the cut gate 24.

A pipe 26 is connected to the upper end of the discharge device 23, and the exhaust gas G sent to the discharge device 23 is discharged through the pipe 26, and a gas cooling tower connected to the pipe 26. 27 is sent.
The gas cooling tower 27 is provided with a cooling spray 28 on its upper side, and the cooling water W is ejected from the cooling spray 28 to cool the exhaust gas G sent to the gas cooling tower 27 with the cooling water W. Solidified dust is removed.
Further, a pipe 29 is connected to the side of the gas cooling tower 27, and the exhaust gas G sent to the gas cooling tower 27, cooled and free of contained dust is removed via the pipe 29. For example, it is sent to a gas processing device or the like.

In the ash melting furnace 10 having the above configuration, when energization is performed between the main electrode 14 and the furnace bottom electrode 17, Joule heat is generated in the molten slag S, and the inside of the furnace body 12 from the ash charging port 15. Melting of the ash X charged into the slag is started, and molten slag S is generated. The melting gradually proceeds from the main electrode 14 side to the outside.
Then, the molten slag S in the furnace body 12 is taken out by appropriately opening the molten slag discharge port 18 on the side wall of the furnace body 12.
Moreover, since the molten salt Y generated together with the molten slag S is lighter than the molten slag S, the molten salt Y is formed in a layered manner on the molten slag S.

The molten salt Y is vaporized by the heat of the molten slag S and volatilized as a chlorine compound Z. Then, the chlorine compound Z is volatilized from the molten salt Y and sent to the flue 21 from the exhaust port 19 together with the exhaust gas G.
And the inside of the flue 21 is heated by the burner 22 provided in the flue 21. Thereby, the exhaust gas G sent into the flue 21 is heated in the flue 21, and the chlorine compound Z contained in the exhaust gas G is heated to 700 ° C. to 1100 ° C. That is, when the chlorine compound Z contained in the exhaust gas G is sent into the flue 21, it is heated in the burner 22 and remains in a liquid state without being cooled and solidified in the flue 21.
Then, this liquid chlorine compound Z is caused to flow in the inclined direction through the flue 21 inclined downward, and sent into the discharge device 23 together with the exhaust gas G.

Thereafter, in the discharge device 23, the liquid chlorine compound Z is stored at the bottom. The liquid chlorine compound Z stored at the bottom of the discharge device 23 is sent to the melt receiving container 25 installed below by opening the opening at the bottom of the discharge device 23 by the cut gate 24. And recovered.
Further, the exhaust gas G sent to the discharge device 23 is sent to the gas cooling tower 27 on the downstream side via the pipe line 26 at the upper end.
The exhaust gas G sent to the gas cooling tower 27 is cooled by the cooling water W ejected from the cooling spray 28 and the contained dust is removed. It is sent to.

As described above, according to the ash melting facility 1 according to the above-described embodiment, the flue 21 connected to the furnace body 12 to guide the exhaust gas G generated in the furnace body 12 of the ash melting furnace 10 is directed downward. In addition, the burner 22 for heating the exhaust gas G fed from the furnace body 12 is provided, so that the chlorine compound Z in the exhaust gas G is heated to maintain the liquid state without solidifying, It can be reliably sent out from the ash melting furnace 10 along the inclined flue 21.
Accordingly, the chlorine compound Z is liquefied and becomes in a softened state with poor fluidity and adheres, and adheres to the inner surface of the flue 21, and then the adhering formation that solidifies is eliminated. It can be surely prevented and contribute to stable operation.

  Further, the backflow of the chlorine compound Z into the furnace body 12 can be reliably prevented, and the promotion of circulation and concentration of the chlorine compound Z in the system is avoided. Thereby, promotion of deterioration of the heat-resistant material due to concentration of the chlorine compound Z can be avoided, and the life can be extended. Furthermore, smooth and stable ash melting is possible, the input power can be used effectively for ash melting, and the quality of the molten slag S can be improved.

Further, by setting the exhaust gas G to 700 ° C. to 1100 ° C. by the burner 22, the chlorine compound Z can be reliably flowed along the flue 21 in a liquid state.
In addition, since the flue 21 is inclined downward by 45 ° or more, the liquid chlorine compound Z can be reliably flowed downstream to prevent the backflow into the furnace body 12.
Furthermore, since the other end 21b of the flue 21 is connected to the discharge device 23, the liquid chlorine compound Z contained in the exhaust gas G can be reliably discharged and recovered.

  The apparatus for heating the exhaust gas G is not limited to the burner 22, and for example, the ash melting furnace 10 itself that melts ash to form the molten slag S may be used as the heating apparatus. That is, by raising the temperature of the chlorine compound Z, which decreases in temperature when passing through the flue 21, by the heat from the ash melting furnace 10, the chlorine compound Z can be reliably maintained in a liquid state without solidifying.

  In addition, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

Schematic configuration diagram explaining the configuration of ash melting equipment

Explanation of symbols

1 Ash melting furnace equipment 10 Ash melting furnace (heating section)
12 furnace body 15 ash inlet 21 flue 21a one end 21b other end 22 burner (heating unit)
23 Discharge device (discharge unit)
X ash S molten slag G exhaust gas Z chlorine compound

Claims (6)

Ash having an ash melting furnace that melts the ash charged into the furnace body from the ash charging port into molten slag, and a flue that is connected at one end to the ash melting furnace and guides the exhaust gas generated in the furnace body A melting facility,
The flue is installed to be inclined downward from one end to the other end connected to the ash melting furnace, and further includes a heating unit that heats the exhaust gas fed from the furnace body. Ash melting equipment.   The ash melting facility according to claim 1, wherein the heating unit is a burner provided in the flue.   The ash melting facility according to claim 1, wherein the heating unit is the ash melting furnace that melts ash to form molten slag.   The said heating part makes exhaust gas 700 degreeC-1100 degreeC, The ash melting installation of any one of Claim 1 to 3 characterized by the above-mentioned.   The ash melting facility according to any one of claims 1 to 4, wherein the flue has an inclination angle of 45 ° or more with respect to the horizontal. 6. The ash melting facility according to claim 1, wherein the other end of the flue is connected to a discharge unit that discharges a chlorine compound contained in the exhaust gas.

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