JPH05288314A - Waste material melting furnace and loading method in waste material melting furnace - Google Patents

Abstract

PURPOSE:To restrict dispersion of dust even in case of poor aeration waste material and to enable a stable melting process to be performed by a method wherein a spacing region is formed over a charging layer formed by some block-like carbonic combustibles loaded from a loading cylinder. CONSTITUTION:Four cokes loading ports 7 are present around a periphery of a ceiling of a furnace body 3. Loading cylinders 8 are inserted into the loading ports 7 in such a manner that their lower ends are positioned above the lower end position of a waste material inserting cylinder 5, and loading cokes charging region 9 is formed in such a manner that it may enclose the loading region 6 with the waste material being applied as a main body, and the cokes are charged in the loading cylinders 8. In addition, a spacing region 11 is formed over the charging region 9 of the loaded cokes. With such an arrangement, even in case of the poor aeration waste materials, they can be stably processed for their melting operations while their aeration within the furnace and their load descending being kept during their restriction against the dust dispersion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to municipal solid waste, various industrial wastes, or intermediate products obtained by drying, incineration, crushing, etc., using a lumpy carbonaceous combustible substance such as coke as a heat source. The present invention relates to a waste melting furnace that heats and melts and recovers as a civil engineering material, a concrete fine aggregate, and a slag material for a surface makeup aggregate.

[0002]

This waste melting furnace itself is disclosed in Japanese Patent Laid-Open No.
No. 82212 and Japanese Patent Laid-Open No. 55-114382, the waste is charged from the top of the shaft furnace together with limestone, silica stone and coke as a basicity adjusting agent, and the oxygen-containing gas or oxygen is supplied from the tuyere. The enriched gas is blown into the furnace, and the carbonaceous matter produced by coke and pyrolysis is burned at high temperature in the high-temperature hearth, and the dry zone, carbonization gasification zone and combustion melt zone formed in the furnace are sequentially As it descends and becomes molten slag, the high temperature combustion exhaust gas rises as a counter flow in the waste packed bed in the shaft and is discharged,
It has a structure to collect it as a combustible gas.

However, with this structure, a large amount of oxygen-containing gas must be supplied in order to stably maintain the molten state of waste, and when waste with poor air permeability is treated. Has a drawback in that the unloading of waste becomes irregular and stable treatment becomes difficult.

Further, Japanese Patent Publication No. 63-49128 discloses that in the waste melting furnace, as a measure for preventing pollution due to entrainment and discharge of dust in combustion exhaust gas and troubles in auxiliary equipment, Disclosed is a structure in which a waste charging cylinder is provided in the center, the lower end is buried in a coke filling area, a coke charging inlet is disposed around the waste charging cylinder, and an exhaust pipe is disposed around the coke charging inlet. Has been done. As a result, the waste is charged in the center and the coke is charged so as to cover the periphery thereof, and dust blowing from the waste filling area due to exhaust gas is prevented by the coke suppressing action.

However, in this melting furnace, since the waste containing no lumpy carbonaceous combustible substance is charged from the center, it is difficult to supply the lumpy carbonaceous combustible substance to the bottom of the furnace, and the formation and maintenance of the high temperature hearth is maintained. Has the drawback of being difficult. Also,
Since the massive carbonaceous combustibles to be filled are distributed at an angle of repose from the core to the peripheral wall, coarse particles with a small pressure drop are vented to the peripheral wall part where the filling height is low, and to the central part where the filling height is high. Fine particles with a large pressure loss tend to be distributed, and the high-temperature gas generated in the high-temperature hearth flows preferentially through the peripheral wall, resulting in insufficient preheat drying of the waste and wasting heat on the peripheral wall. Therefore, there is a problem that the thermal efficiency is deteriorated, and therefore the fuel ratio is increased and the oxygen enrichment ratio is increased, so that the uneconomical operation is forced.

Further, in order to solve the problems of increased entrained dust and insufficient calorific value caused by uneven distribution of coke in the waste melting furnace, the applicant of the present invention has disclosed in Japanese Patent Application Laid-Open No. 3-56.
In the publication No. 11, waste and coke, and a basicity adjusting agent are charged from a charging pipe inserted from above the center of the furnace body, and the waste and coke are formed around the filling area.
Disclosed is a waste melting furnace in which a lumpy carbon-based combustible material is uniformly distributed and filled in a hollow cone-shaped furnace without forming a space.

However, in this melting furnace, since the exhaust gas pipe is directly connected to the filling region of the lumpy carbonaceous combustible material, the dust in the high-speed gas discharged from the packed bed is lumpy carbon near the inlet of the flue gas pipe. The concentrated carbon-based combustible substances adhere to each other, which causes the massive carbon-based combustible substances to adhere to each other due to the dust, and the breathability and descent of the packed bed cannot be smoothly performed.
A new problem arose that stable operation would not be carried out.

In order to solve this problem, a waste melting furnace that forms a waste filling area containing coke just above the high temperature hearth and forms a space area above the coke filling area surrounding the waste filling area is proposed. was suggested. As a result, due to the header function of this space region, the exhaust gas is in a state where the gas flow velocity is sufficiently reduced, and the exhaust gas with a small amount of dust entrained can be extracted, and stable furnace operation can be performed.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to efficiently form such a space, whereby
An object of the present invention is to provide a waste melting furnace that can perform stable melting processing while suppressing dust scattering even with waste having poor air permeability, and that has high thermal efficiency.

[0010]

In the waste melting furnace of the present invention, a tuyere is provided in the lower part of a hollow cone-shaped furnace body whose upper part is enlarged and whose inner surface is formed to be at or above the repose angle of massive carbonaceous combustible material. , A tap hole is provided at a position lower than the tuyere, and a waste charging cylinder for charging waste and massive carbonaceous combustible substances from the center of the upper surface of the furnace body has its filling area at the lower end and the tuyere placement level. It is inserted and arranged so that it is located at a level between the waste charging cylinder on the upper surface of the furnace body, and a mass is formed on the peripheral surface of the furnace upper surface away from the waste charging cylinder. In a waste melting furnace provided with a carbon-based combustible material charging port, the charging cylinder is inserted from the massive carbon-based combustible material charging port so that the tip thereof is located at a position higher than the insertion tip of the waste charging cylinder, Formed by the lumpy carbonaceous combustible substance charged from the lumpy carbonaceous combustible substance charging cylinder. Characterized in that the structure forming the space region above the packed bed that.

Further, the charging method of the waste melting furnace is characterized in that the lump carbonaceous combustible material charging cylinder in the periphery is filled with the lump carbonaceous combustible material.

[0012]

[Function] Since a charging cylinder for the lumpy carbonaceous combustible material in the periphery is provided near the peripheral wall of the furnace body, and the tip is buried in the charged packed bed of the lumpy carbonaceous combustible material, it is arranged. Above the furnace body, a space is likely to be formed between the waste charging cylinder whose tip is buried in the waste packing layer in the center and the bulk fuel charging cylinder.

In addition, by filling the inside of the lumped carbonaceous combustible substance charging cylinder with a carbonaceous combustible substance to have a material sealing effect, the hot gas generated in the furnace is charged into the surrounding lumped carbonaceous combustible substance. It becomes difficult for the charging tube to flow toward the charging device portion, and the charging device can be protected from dust and high temperature gas.

[0014]

EXAMPLE FIG. 1 shows an example in which coke is used as the lumpy carbonaceous combustible substance in the present invention, and FIG. 2 is a view showing a plane structure as seen from line AA in FIG.

In these figures, the waste melting furnace 10
Is a shape in which the diameter of the upper portion is expanded to 5 times the diameter of the cross-sectional portion of the lower tuyeres 2 in the two tuyeres 1 and 2 so that the superficial velocity of the combustion exhaust gas is reduced. 20 to 80 mm
Angle of inclination greater than the angle of repose when using diameter coke 70
It consists of a hollow cone-shaped furnace body 3 having a certain degree. The inclination angle and dimensional ratio below the inner wall are changed when the medium mass of blast furnace coke is used and are changed depending on the characteristics of the massive carbonaceous combustible material used, such as petroleum coke, pitch coke, and electrode scrap. Is preferred.

The tuyeres 1 and 2 of the furnace body are installed around the furnace body, respectively, and from the upper tuyeres 1 and the lower tuyeres 2, the coke in the furnace is burned to form a grate of a high temperature atmosphere. Blow in preheated air as you would.

Further, at the lower part of the furnace body 3, there is provided a tap hole 4 for discharging the ash content of the waste, the incombustible content, the coke, and the ash content of the limestone at a high temperature and discharging the molten slag having the adjusted basicity. ing. It is also possible to provide a plurality of tap holes 4 of the same shape at equal intervals, use only one during operation, and install the furnace body by rotating it when restarting after the furnace is stopped and use them alternately. ..

From the center of the ceiling of the furnace body 3, waste A
The lower end of the charging cylinder 5 for charging the coke B and the limestone C for adjusting the basicity of the melt is formed above the level of the upper tuyere 1 by the charging material from the waste charging cylinder 5. It is inserted and arranged at a position where it is buried in the filling area 6 mainly composed of the discarded waste.

Further, four coke charging ports 7 are arranged on the peripheral edge of the ceiling of the furnace body 3, and a charging cylinder 8 is installed in each charging port 7.
However, it is inserted so that its lower end is located above the lower end of the waste insertion cylinder 5 and surrounds the filling area 6 mainly composed of waste, and the charging coke filling area 9 is filled.
Is formed, and the charging cylinder 8 is filled with coke. Further, a space area 11 is formed above the charging area 9 of the charging coke.

The coke B is sieved in advance, the one having a large particle size is charged from the charging cylinder 5, and the one having a small particle size is charged into the peripheral coke charging port 7 to change the particle size of the coke. Is desirable from the standpoint of ventilation into the waste filling area.

Reference numeral 12 denotes a gas exhaust pipe provided on one side of the ceiling of the furnace body 1, which is vertically connected so as to prevent dust accumulation. The gas exhaust pipe 12 can also be provided in the waste charging cylinder 5.

Reference numeral 13 is a high temperature hearth area due to coke B concentrated in the vicinity of the hearth by the dropping of the melted waste heated and heated by the air blown from the lower tuyere 2 below the filling area of the mixture of waste and coke. Indicates.

The broken line shows the processing system of the combustion exhaust gas E, and the secondary combustion chamber 14, the air preheater 15, the gas cooler 16, the dust collector 17, and the smoke washing device 1 are provided from the gas exhaust pipe 12 provided in the furnace.
8, an example in which the air is discharged through the induction blower 19 and the chimney 20 is shown, but a recovery system as a combustible gas may be used. Reference numeral 21 is a blower fan for blowing air to the tuyere.

When the waste melting furnace 10 is operated, the coke having a relatively small diameter is filled in the waste filling area 6 made of a mixture of the waste charged from the charging cylinder 5, limestone, and large-sized block coke. Is charged from the charging cylinder 8 at the peripheral edge and forms a coke filling area 9 in a state of surrounding the periphery of the waste filling area 6. The upper surface thereof has a space angle between the cylinder wall and the cylinder wall of the waste charging cylinder 5 due to the angle of repose caused by the natural flow of the charging coke and the charging cylinder 8 being inserted into the furnace for a long time. 11 is easily formed.

In this state, the waste filling area 6 is 700 to 10
While reaching the temperature of 00 ℃ and reaching the high-temperature hearth area 13, ash and incombustibles rapidly soften, melt, and melt the voids of the grate of the coke due to the radiant heat from the red-hot coke and the hot exhaust gas from the combustion of the coke. ， Dripping and discharging from the tap.

Further, in the coke filling area 9, heat exchange is carried out while flowing countercurrently to the discharged combustion exhaust gas and descending, and when the coke rises in temperature gradually and reaches the upper tuyeres 1, it rises from below. It is heated to a higher temperature by the heat obtained by preferentially burning part of the CO gas in the combustion exhaust gas, and part of the blown oxygen is burned in the coke distributed around the inside of the charging cylinder 5. Let

At this portion, as described above, the softening and melting of ash and incombustibles have started, and it is relatively difficult for the ascending gas to pass through. However, a ring-shaped coke layer is formed on the peripheral wall side. Is formed, and the rising gas passes through this portion having good air permeability. At this time, the ascending gas maintains a uniform flow in the circumferential direction and the flow velocity is increased, so that heat transfer is promoted at the boundary below the waste filling region 6.

Further, the filling area formed by the combustible substance charged by the coke charging cylinder 8 surrounds the filling layer mainly composed of wastes formed in the central portion of the furnace body and covers from above. Further, the space area 11 can be surely formed above the massive combustible material layer-packed layer. As a result, the exhaust gas port 12 is sufficiently reduced in the gas flow rate.
Since it is emitted from the exhaust gas, it becomes an exhaust gas with little dust entrainment.

On the other hand, gas intrusion into the coke charging device in the vicinity is reduced, and the charging device can be protected from dust and high temperature gas.

[0030]

The present invention has the following effects.

(1) A high-temperature hearth can be reliably formed, and even a waste material with poor air permeability can be stably melted while maintaining air permeability and unloading in the furnace while suppressing dust scattering.
A waste melting furnace with high thermal efficiency can be realized by improving the effect of preheating and drying exhaust gas.

(2) By mainly passing the exhaust gas generated from the high-temperature hearth through the lumpy carbonaceous combustible substance-packed layer around the waste-packed layer having good air permeability, dust scattering from the waste can be minimized, and Dust that has once scattered is also captured in the process of passing through the packed bed of massive carbonaceous combustible material,
The dust accompanying the exhaust gas finally discharged from the furnace can be suppressed, and the gas flow in the furnace can be stabilized because the packing layer has good air permeability.

(3) Since the upper part of the packed bed of the waste lump carbonaceous combustible material can be formed such that the charging surface height is high in the peripheral wall part and low in the furnace center part, the lump-shaped mass with large particle size is formed in the furnace center part. The carbon-based combustible material can be distributed, and the high-temperature exhaust gas generated mainly in the high-temperature hearth can flow near the waste packed bed.Therefore, the high-temperature exhaust gas accelerates the preheat drying of the waste, thus reducing the fuel cost. Can be reduced. At that time,
By providing a cylinder for charging the surrounding lumpy carbonaceous combustible substance by filling the lumped carbonaceous combustible substance packing layer, the exhaust gas in the upper space of the hollow cone can be charged into the surrounding lumpy carbonaceous combustible substance by the material sealing effect. It is possible to prevent troubles of the charging device due to heat and dust contained in the device.

(4) It is possible to reliably form a space above the lumpy combustible substance-packed layer, which allows the gas to be discharged from the lumpy carbonaceous combustible substance-packed layer in a state where the gas flow velocity is sufficiently reduced. Exhaust gas with less dust can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a planar structure seen from line AA of FIG.

[Explanation of symbols]

A waste B coke C limestone D blast air E combustion exhaust gas 1, 2 tuyeres 3 hollow cone-shaped furnace body 4 tap hole 5 waste charging cylinder 6 waste-filled area 7 coke charging port 8 coke Charging cylinder 9 Charging coke filling area 10 Waste melting furnace 11 Space area 12 Gas exhaust pipe 13 High temperature hearth area 14 Secondary combustion chamber 15 Air preheater 16 Gas cooler 17 Dust collector 18 Smoke washing device 19 Induction blower 20 Chimney 21 Blower fan

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Kunihiro Watanabe 59 Nippon Steel Plant Design Co., Ltd., 46 Nakahara, Tobata-ku, Kitakyushu, Fukuoka

Claims (2)

[Claims] 1. A tuyere is provided in the lower part of a hollow cone-shaped furnace body whose upper part is enlarged and the inner surface is formed to have a repose angle of a massive carbonaceous combustible material or more, and a tap hole is provided at a position lower than the tuyere. A waste charging cylinder for charging waste and massive carbonaceous combustible substances from the center of the upper surface of the furnace body is inserted and arranged so that its lower end is located at a level between the filling area and the tuyere arrangement level. , A gas discharge port is provided around the waste charging cylinder on the upper surface of the furnace body,
In a waste melting furnace in which a lumpy carbonaceous combustible substance charging port is provided at a peripheral portion of the upper surface of the furnace body, which is distant from the waste charging barrel, the charging cylinder is introduced from the lumpy carbon type combustible substance charging port, and the tip thereof is the waste. A structure that is inserted at a position higher than the insertion tip of the charging cylinder and forms a space region above the packed bed formed by the massive carbon combustible material charged from the massive carbon combustible material charging cylinder. And waste melting furnace. 2. A charging method for a waste melting furnace, characterized in that the lumpy carbonaceous combustible substance charging cylinder in the periphery is filled with the lumpy carbonaceous combustible substance.