JP2005090792A - Coke bed type melting treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coke bed type melting treatment device capable of separating metal from molten slag to produce the slag of high quality by improving a condition of the molten slag in a furnace bottom. <P>SOLUTION: In a melting furnace 1 constituting this coke bed type melting treatment device, a slag tapping port 32 and a metal tapping port 33 are formed in upper and lower two stages in the furnace bottom 30, a pair of furnace bottom tuyeres 34 are formed, and the air-blasting direction from each furnace bottom tuyere is offset to an outer side with respect to a center O of the furnace bottom in a plan view. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a coke bed type melt processing apparatus, which relates to a coke bed type melt processing apparatus that separates metal contained in the slag from the melt processed slag and generates high-quality slag.

Conventionally, in order to melt incineration ash and the like into slag, a coke bed type melt processing apparatus is used in which a lump processed product is put into a melting furnace together with coke, and the processed product is melted in the furnace. Yes. As shown in FIG. 6, the melting furnace 101 is a structure including a furnace top 110, a furnace body 120, and a furnace bottom 130, and this structure is supported by a frame 140.
The furnace top 110 is provided with a charging port 111 and a double damper device 112. The double damper device 112 prevents the gas from being released into the atmosphere from the melting furnace 101 when the processed material B and the coke C are charged into the melting furnace 101 from the charging port 111.

The furnace body 120 is below the furnace top 110 and has a vertically long cylindrical shape. A plurality of exhaust holes 120a are opened at equal intervals on the upper side wall of the furnace body 120, and the periphery of these exhaust holes is surrounded by smoke. A road 121 is formed, and an exhaust gas outlet 122 is connected to the flue 121.
An annular duct 123 is provided in the middle of the furnace body 120, and a plurality of furnace body tuyere air ducts 124 project from the annular duct 123. The discharge outlets at the tip of each furnace body tuyer tube 124 are inserted into the furnace body 120 from a plurality of furnace body tuyeres 125 provided below the furnace body 120, and each discharge port is a plane of the furnace body 120. It is arranged so as to face in the direction of the center O of the furnace body 120 in the view and slightly downward in the front view of the furnace body 120. The annular duct 123 is supplied with a mixture of air and oxygen heated by a heat exchanger (not shown) provided in the exhaust gas path, and this mixed gas is distributed to each furnace tuyere vent pipe 124. Thus, the air is blown from the furnace body tuyere 125 toward the center O of the furnace body 120.

The furnace bottom 130 is in the lower stage of the furnace body 120 and is provided with a slag hot water outlet 132.
A ladle 150 is movably disposed in the lower space of the furnace bottom 130 and is configured to receive molten slag Sm discharged from the slag hot water outlet 132.
In such a melting furnace 101, the processed material B and the coke C are charged into the melting furnace 101 from the charging port 111 of the furnace top 110, and the processed material B and the coke C are stacked and filled in the melting furnace 101. In the furnace body 120, the coke C in the vicinity of the furnace body tuyere 125 is blown and burned with the mixed gas from the furnace body tuyere 125, and the processed material B is melted by the combustion heat to become molten slag Sm. The coke C at the center of the furnace body 120 in the combustion state is at the highest temperature, and the coke C itself is combusted and melted, so that a melting region Zm is formed in the furnace body 120. The molten slag Sm descends in the melting furnace 101 from the furnace body 120 toward the furnace bottom 130 using the melting region Zm as a passage.

Although the coke C is also filled in the furnace bottom 130, most of the coke C is in an unburned state in the furnace bottom 130. The unburned coke C supports the coke C in the combustion state at the upper side. On the other hand, the coke C in a narrow range through which the molten slag Sm passes at the center of the furnace bottom 130 is combusted and melted by the heat of the molten slag Sm to form a molten region Zm.
The molten slag Sm descends in the melting furnace 101 and reaches the furnace bottom 130, is discharged from the slag hot water outlet 132, is received by the ladle 150, is pulverized after slow cooling, and is used as a roadbed material or the like.
The incineration ash and the like to be melt-processed contains a wide variety of incineration residues from general waste to industrial waste, and contains metal M. For this reason, in order to use the slag S that has been slowly cooled and crushed as a roadbed material, it is required to remove the metal M from the molten slag Sm and improve the quality of the molten slag Sm that is discharged.

In order to improve the quality of the molten slag Sm discharged from the melting furnace, there is a method of separating substances mixed in the molten slag Sm using a specific gravity difference (see Patent Document 1). In this separation method, as shown in FIG. 7, in a direct energization type melting furnace 201 in which a heater 238 extends in the furnace, slag outlets 232 and metal outlets 233 are provided at two locations above and below the furnace body 220. . Then, a liquid pool of molten slag Sm is formed from the middle to the bottom of the furnace body 220, and the substances are separated using the specific gravity difference. Separation using the difference in specific gravity requires a certain amount of settling time, so that a sufficient amount of molten slag Sm in the melting furnace 201 is provided, that is, a large pool of molten slag Sm is formed. It is preferable to separate the substances mixed in the molten slag Sm.
JP 58-30382 A

In the melting furnace 101 of the coke bed type melting processing apparatus, when a substance mixed in the molten slag Sm is separated using a specific gravity difference, it is necessary to form a liquid pool of a certain amount of the molten slag Sm in the melting furnace 101. However, if most of the melting furnace 101 is the melting region Zm from the furnace body 120 to the furnace bottom 130, the unburned coke C is reduced in the furnace bottom 130, and the upper coke C or It becomes difficult to support the processed product B. For this reason, it is necessary that a certain amount of unburned coke C exists in the furnace bottom 130, and it is heated using a heater that extends into the melting furnace 101 as in the melting furnace 201 of FIG. 7. The large melting region Zm cannot be formed in the furnace bottom 130. Therefore, the melting zone Zm in the furnace bottom 130 is formed only in a narrow range through which the molten slag Sm passes, and a sufficient liquid pool is not formed. Therefore, it becomes difficult to separate the metal M from the molten slag Sm by the specific gravity difference. Even if the slag hot water outlet and the metal hot water outlet are provided at two locations on the upper and lower sides of the furnace bottom 130, the high-quality molten slag Sm cannot be obtained.
The present invention solves the above problems, and its object is to improve the state of the molten slag at the furnace bottom, thereby separating the metal from the molten slag and producing a high-quality slag. It is to provide a type melt processing apparatus.

In order to solve the problem, the present invention is a coke bed type melting processing apparatus in which a processed product and coke are put into a melting furnace, and the processed product is melted in the furnace. A pouring gate is provided in two upper and lower stages, and a furnace bottom tuyere for blowing air to the furnace bottom is provided.
In this coke bed type melt treatment device, blowing from the furnace bottom tuyere increases the melting area in the furnace bottom and increases the amount of molten slag pool, and the metal in the molten slag settles due to the difference in specific gravity. It becomes easy, the molten metal slag is removed from the upper slag outlet, and the molten slag having a high quality is discharged, and the metal separated from the molten slag can be discharged from the lower metal outlet.

  In this coke bed type melting processing apparatus, a plurality of furnace bottom tuyere is provided in the furnace bottom, and the blowing direction from each furnace bottom tuyere is offset outward with respect to the center of the furnace bottom in a plan view. The distribution of the melting region at the bottom of the furnace spreads and stabilizes at the center of the furnace bottom and its vicinity.

  The coke bed type melt treatment apparatus of the present invention has an effect of separating the metal from the molten slag by improving the state of the molten slag at the furnace bottom, and producing high-quality slag.

FIG. 1 is a front view showing a cross section of a part of a melting furnace of a coke bed type melting processing apparatus according to an embodiment of the present invention, FIG. 2 is a front view in which a part of the furnace bottom is broken, and FIG. 4 is a longitudinal sectional view taken along the line A-O-D in FIG. 3, and FIG. 5 is a longitudinal sectional view taken along the line A-O-E in FIG.
The melting furnace 1 of the coke bed melting apparatus shown in FIG. 1 has the same basic configuration as the conventional one except for the configuration of the furnace bottom 30.
That is, the melting furnace 1 is a structure that includes a furnace top 10, a furnace body 20, and a furnace bottom 30 and is supported by the frame 40.
At the furnace top 10, an inlet 11 that allows the processed material B and coke C to be charged into the melting furnace 1, and the gas in the melting furnace 1 is released to the atmosphere when the processed material B is charged from the charging port 11. A double damper device 12 is provided to prevent this.

A vertically long cylindrical furnace body 20 under the furnace top 10 has a plurality of exhaust holes 20a opened at equal intervals on the upper side wall thereof, and an exhaust gas outlet 22 is connected to a flue 21 surrounding these exhaust holes. ing.
From the annular duct 23 in the middle of the furnace body 20, a plurality of furnace body tuyere air ducts 24 project, and a discharge port at the tip of each furnace body tuyere air duct 24 is opened below the furnace body 20. The furnace body tuyere 25 is inserted into the furnace body 20, and each discharge port is disposed so as to face the center O direction of the furnace body 20 in a plan view of the furnace body 20 and slightly downward in a front view of the furnace body 20. Has been. The annular duct 23 is supplied with a mixed gas of air and oxygen heated by a heat exchanger (not shown) in the exhaust gas path, and this mixed gas is distributed to each furnace tuyere air blower tube 24. Further, it is configured such that continuous air blowing is possible from the furnace body tuyere 25 toward the center O of the furnace body 20.

There is a furnace bottom 30 at the lower stage of the furnace body 20, and a ladle 50 is movably disposed in a lower space of the furnace bottom 30, and from the molten slag Sm discharged from the slag hot water outlet 32 and the metal hot water outlet 33. It is configured such that the metal M to be taken out can be received in the ladle 50.
As shown in FIGS. 2 to 5, the furnace bottom 30 has a cylindrical shape, and the inner bottom surface 31 of the furnace bottom 30 is gently inclined. The side wall of the furnace bottom 30 is provided with a slag hot water outlet 32 and a metal hot water outlet 33 in two upper and lower stages, and the height position of the slag hot water outlet 32 is higher than the height position of the metal hot water outlet 33. The height position of the gate 33 substantially coincides with the height position of the inner bottom surface 31. In a plan view of the furnace bottom 30, the positions of the slag outlet 32 and the metal outlet 33 on the side wall of the furnace bottom 30 are separated from each other in the circumferential direction of the furnace bottom 30.

  In addition, two furnace bottom tuyere 34 which are paired are formed on the side wall of the furnace bottom 30 with an interval of 180 °, and each furnace bottom tuyere 34 is inserted with a furnace bottom blowing pipe 35. Yes. The furnace bottom blowing pipe 35 is a double pipe, and the outer passage of the double pipe forms an air supply pipe 36 and the inner passage forms an oxygen supply pipe 37. The furnace bottom blowing pipe 35 is configured such that the flow rate of air and oxygen can be independently controlled by a flow rate control valve (not shown), and a mixed gas of air and oxygen can be intermittently blown into the furnace bottom 30. The furnace bottom blow pipe 35 at each furnace bottom tuyere 34 is offset by a distance d outward from the center O of the furnace bottom 30 in the plan view of the furnace bottom 30, and the furnace body in the front view of the furnace bottom 30. It arrange | positions so that it may face downward with the inclination angle (theta) smaller than the inclination angle of the tuyere 25. FIG.

Next, the operation will be described.
The processed material B and the coke C are charged into the melting furnace 1 from the charging port 11 of the furnace top 10, and the processed material B and the coke C are stacked and filled in the melting furnace 1. In the furnace body 20, the coke C in the vicinity of the furnace body tuyere 25 is continuously blown and burned with the mixed gas from the furnace body tuyere 25, and the processed material B is heated by this combustion heat to become molten slag Sm. . The central portion of the coke C in the combustion state is at the highest temperature, and the coke C itself is combusted and melted, so that a melting region Zm of the coke C is formed in the furnace body 20. The molten slag Sm descends in the melting furnace 1 from the furnace body 20 toward the furnace bottom 30 using the melting region Zm as a passage.

The coke C is also filled in the furnace bottom 30, and the coke C in the range through which the molten slag Sm passes at the center in the furnace bottom 30 is melted by the heat of the molten slag Sm to form a molten region Zm.
When a mixed gas of air and oxygen is intermittently blown into the furnace bottom 30 from the furnace bottom blowing pipes 35 of the two opposed furnace bottom tuyere 34, the combustion region of the coke C in the furnace bottom 30 is near the center O of the furnace bottom 30. It expands and the melting zone Zm in the furnace bottom 30 also expands. Since the blowing direction of the mixed gas blown from each furnace bottom tuyere 34 is offset from the center O of the furnace bottom 30 by a distance d, the combustion region of the coke C is expanded near the center O of the furnace bottom 30 and is stable. The melting region Zm can also be expanded to the vicinity of the center O of the furnace bottom 30 and stabilized.

  The coke C in the vicinity of the inner surface of the side wall in the furnace bottom 30 has a lower temperature than the coke C in the combustion region and is in an unburned state. The coke C in the unburned state supports the coke C in the upper combustion state. Since the blowing of the furnace bottom tuyere 34 is performed intermittently, the melting region Zm is expanded more than necessary, and the unburned coke C as a structural member is not burned and melted.

  Accordingly, a somewhat large pool of molten slag Sm is formed in the melting region Zm at the center of the furnace bottom 30. In this liquid pool, the metal M derived from the processed material B and mixed in the molten slag Sm has a large specific gravity, so it settles down to the inner bottom surface 31, and high-grade molten slag Sm accumulates in the upper part of the liquid pool. . Moreover, since the blowing direction of the mixed gas blown from the paired furnace bottom tuyere 34 is offset from the center O of the furnace bottom 30, the molten slag Sm in the melting region Zm to which the mixed gas is blown is moderated. , And more favorable sedimentation conditions of the metal M are given, so that the sedimentation of the metal M is promoted.

The inclination angle θ of the furnace bottom tuyere 34 is set smaller than that of the furnace tuyere 25, and the mixed gas is not directly blown into the liquid pool of the molten slag Sm. Therefore, turbulent flow unfavorable for the sedimentation of the metal M does not occur in the molten slag Sm.
Then, high-quality molten slag Sm is discharged from the slag outlet 32 on the upper side of the side wall of the furnace bottom 30 and enters the ladle 50. The molten slag Sm that has entered the ladle 50 is pulverized after slow cooling to obtain high-quality slag from which the metal M has been removed, and can be used for roadbed materials and the like. Further, the metal M that has settled down to the inner bottom surface 31 flows along the inclination of the inner bottom surface 31 and is discharged from the metal outlet 33.

  In the present embodiment, two furnace bottom tuyere 34 forming a pair are opened in the furnace bottom 30 with an interval of 180 ° in the circumferential direction, but the number of furnace bottom tuyere 34 is two. Needless to say, the interval between the furnace bottom tuyere 34 is not limited to 180 °. For example, the number of furnace bottom tuyere 34 to be opened may be three, and the blowing direction of the mixed gas blown from each furnace bottom tuyere 34 may be offset from the center O of the furnace bottom 30. Further, the intervals between the three furnace bottom tuyere 34 may be different from each other without being equal.

It is a front view which shows a part of melting furnace of the coke bed type melting processing apparatus which concerns on this Embodiment by a cross section. It is the front view which fractured | ruptured a part of furnace bottom. It is a top view of a furnace bottom. 4 is a vertical cross-sectional view taken along line A-O-D in FIG. FIG. 5 is a longitudinal sectional view taken along line A-O-E in FIG. It is the front view which showed the conventional coke bed type melt processing apparatus as a part in cross section. It is sectional drawing of the melting furnace which fractionates a metal from the molten slag using the conventional specific gravity difference.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Melting furnace 10 Furnace top 11 Input port 12 Double damper device 20 Furnace body 21 Flue 22 Exhaust gas outlet 23 Annular duct 24 Furnace tuyere blow pipe 25 Furnace tuyere 30 Furnace bottom 31 Furnace bottom inner bottom 32 Slag outlet 33 Metal outlet 34 Furnace bottom tuyere 35 Furnace bottom ventilation pipe 36 Air supply pipe 37 Oxygen supply pipe 40 Frame 50 Ladle B Processed material C Coke Sm Melting slag M Metal Zm Melting zone

Claims (2)

  A coke bed type melt processing apparatus for charging a processed material and coke into a melting furnace and melting the processed material in the furnace, and providing a slag outlet and a metal outlet in two stages on the furnace bottom A coke bed type melting apparatus characterized by providing a furnace bottom tuyere for blowing air to the furnace bottom.   The coke bed type melting according to claim 1, wherein a plurality of furnace bottom tuyere are provided so that a blowing direction from each furnace tuyere is offset outwardly with respect to a center of the furnace bottom in a plan view. Processing equipment.

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