JP2629108B2 - Waste melting furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to municipal solid waste, various industrial wastes, or intermediate products obtained by drying, incineration, crushing, etc., using a massive carbon-based combustible material such as coke as a heat source. The present invention relates to a melting furnace that is heated and melted to recover as civil engineering material, concrete fine aggregate, and slag material for surface decorative aggregate, and more particularly to a structure of a tap hole portion thereof.

[0002]

2. Description of the Related Art In this waste melting furnace, waste containing a coke blended with limestone and silica stone as a basicity adjusting agent is charged from the top of the furnace, and an oxygen-containing gas or an oxygen-enriched gas is supplied from a tuyere into the furnace. And the coke is burned at a high temperature, and the drying zone, the carbonization gasification zone and the combustion melting zone in the furnace are sequentially lowered to form molten slag.

[0003] In a waste melting furnace, the properties of the waste change, so that the properties of the melt change and the viscosity also changes. In particular, when the viscosity is high, it becomes difficult to discharge the melt from the tap hole, and in an extreme case, the melt port is blocked.

[0004] Therefore, as for the tap hole, in order for the melt to drop stably from the flow path at the tip of the tap hole, the temperature of the melt drops and the fluidity deteriorates in order to stabilize the tapping of the melt. Therefore, it is necessary to suppress the phenomenon of sticking and growing in the flow channel.
In addition, it is necessary to consider the harmless derivation of flammable gas containing a large amount of CO ejected with the melt,
Further, it is necessary to maintain a good working environment for maintenance and inspection by the operator.

Conventionally, as a structure of a tap hole of this waste melting furnace, Japanese Utility Model Application Laid-Open No. 58-58240 discloses a cover for guiding a jet gas downward, thereby keeping the heat of the melt and the combustible A structure in which a gas is guided out of the system is disclosed.

However, the heat retention of the melt by the guide cover alone is insufficient, so that the fluidity of the melt deteriorates, and the tap hole tends to be clogged, and may be completely clogged in extreme cases. . Furthermore, since the combustible gas ejected from the tap hole has no oxygen in the guide cover and comes into contact with the atmosphere only when it comes out of the guide cover, the molten material on the tap hole channel cannot be kept warm. In addition, mixing with the atmosphere was not complete, but incomplete combustion occurred, making it difficult to maintain a good environment.

In Japanese Utility Model Publication No. Sho 61-43070, a tuyere is added in the vicinity of the tap hole to increase the temperature in the vicinity of the tap hole, and the temperature in the vicinity of the inside of the tap hole is increased. Since it is in the system flammable substance packed bed, the combustion exhaust gas burned at the tuyere is discharged from the tap as a flammable gas containing CO gas. Therefore, the massive carbon combustible material is consumed more than necessary. In addition, since the temperature near the taphole in the furnace becomes locally high, refractory wear occurs locally. Furthermore, the melt does not take measures as it causes a temperature drop especially at the tap hole outlet.

Further, Japanese Patent Publication No. 2-606 discloses a structure in which a gas discharged from a tap is connected to a main exhaust gas pipe by a duct without burning the gas. No special measures have been taken.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to maintain a good flow state in a melt to be extracted, and to realize a stable operation of a furnace, a tap hole structure for effectively utilizing a combustible gas to be jetted out. The object of the present invention is to provide a waste melting furnace having:

[0010]

SUMMARY OF THE INVENTION According to the present invention, a waste material is charged with a basicity adjuster and a bulk carbonaceous fuel from the top, and a combustion gas is blown from a tuyere provided at a lower portion. the was melted slag, the waste melting furnace to extract the molten material from hot water port formed in a lower position than the tuyere, the tap hole
The furnace side direction, sideways provided a forehearth for receiving the extract melts and surrounds the outflow position is arranged, the tap hole in the front furnace
U-shaped header around U-shaped opening
Provided in the orientation, double directed to the tap hole in the header
A number of combustion gas spray nozzles are arranged.

[0011]

[Effect] The gas ejected from the tap is a combustible component C
O is contained in about 30%, and by burning this, it becomes possible to keep heat near the tip of the tap hole where the melt falls by the gas radiation.

Further, by providing the forehearth, it is possible to further enhance the heat retention effect by solid radiation on the inner wall of the forehearth in addition to gas radiation. Once separated from the tip of the taphole and begins to fall into the lower space, no sticking growth occurs even if the temperature of the melt is slightly lowered.

Further, since the oxygen-containing gas for combustion is forcibly blown from the nozzle, the mixing with the ejected gas is promoted to enable complete combustion, and the forehearth can be completely shut off from the atmosphere. The environment is also improved.

[0014]

FIG. 1 shows the entire structure of a melting furnace according to the present invention.

In FIG. 1, a waste melting furnace 10 has a diameter of an upper portion which is a cross section of the upper tuyere 1 in two tuyeres 1 and 2 so that the superficial velocity of the flue gas is reduced. It has a hollow cone-shaped furnace body 3 having a shape enlarged to five times the diameter and having an inclination angle of 70 degrees or more at the repose angle when coke having a diameter of 20 to 80 mm is used below the inner surface.

The tuyeres 1 and 2 of the furnace body are provided around the furnace body, each having six tuyeres. The upper tuyeres 1 and the lower tuyeres 2 burn the coke in the furnace to form a grate in a high-temperature atmosphere. Blow in preheated air as you do.

Further, the ash content of the waste,
A tap hole 4 is provided for discharging molten slag in which incombustible components, coke, and limestone are melted and mixed at a high temperature, and the basicity of which is adjusted.

A charging cylinder 5 for charging waste A, coke B, and limestone C for adjusting the basicity of the melt is mounted from the center of the ceiling of the furnace body 3.

The charge from the charging cylinder 5 is charged together with the limestone C in the form of a layer or a mixture of 40 to 80% of the waste A and the coke B. Furthermore, coke B
May be changed, and the particle size of the coke may be changed so that the large particle size is charged into the charging cylinder 5 and the small particle size is charged into the peripheral coke charging inlet 6. The peripheral coke inlet 6 is open to the inner ceiling at four locations on the outer peripheral upper surface. Reference numeral 7 denotes a gas exhaust pipe provided on one side of the ceiling of the furnace body 3, which is connected vertically so as not to accumulate dust. Further, the gas exhaust pipe 7 can be provided also in the waste charging cylinder 5.

Reference numeral 8 denotes a coke filling area formed in the furnace inside by the coke B charged from the charging inlet 6.
Reference numeral 9 denotes a high-temperature hearth region formed immediately below the central charging cylinder 5 from the center near the furnace bottom, and above the waste A, coke B, and limestone charged by the charging cylinder 5 are located above the high temperature hearth area. C, a waste-filled area 11 composed of a mixture with
The lower end of the charging cylinder 5 for charging the coke B and the limestone C is buried in the waste filling area 11.

Further, reference numeral 12 denotes a space formed between the coke filling region 8 and the furnace ceiling. The formation of this space 12 reduces the dust in the exhaust gas discharged from the gas exhaust pipe 7 and reduces the amount of dust. Gas can be discharged smoothly.

A broken line indicates a processing system for the flue gas E, and a secondary combustion chamber 13, an air preheater 14, a gas cooler 15, a dust collector 16, and a smoke cleaning device 1 are connected through a gas exhaust pipe 7 provided in the furnace.
7. Although an example is shown in which the air is discharged through the induction blower 18 and the chimney 19, a recovery system as combustible gas may be used. Reference numeral 20 denotes a blower fan for sending air preheated by the air preheater 14 to the tuyeres 1 and 2.

Reference numeral 21 denotes a forehearth which surrounds the tap hole 4. The forehearth 21 blows combustion air from the introduction box 23 through the flow control valve 22 to the tap hole 4 so as to be flammable. Is provided, which keeps the temperature of the melt M at about 1450 ° C., prevents the tap hole 4 from being clogged, and heats the forehearth 21;
Further, the melt M flowing down from the bottom (not shown) of the forehearth
It is carried out to a processing device for commercialization. During this time, the melt is shut off from the atmosphere, and the surrounding environment can be maintained well. Reference numeral 25 denotes an exhaust port for discharging exhaust gas in the forehearth 21, and this exhaust gas is mixed with exhaust gas from the furnace body 3 and subjected to gas treatment.

2 and 3 show details of the structure of the forehearth shown in FIG.

FIG. 2 is an enlarged view of the nozzle section 24 shown in FIG. 1, and FIG. 3 is a front view as viewed from the line AA in FIG.

In these figures, a combustion air header 26 is formed in an inverted U-shape to cover the upper part of the hole 41 of the tap hole 4 on the front surface of the tap hole 4 provided at the bottom of the furnace body 3 at an angle. A plurality of nozzles 27 are arranged on the header 26 so as to be directed above the hole 41 of the tap hole, and blow air from the air inlet pipe 28 to effectively combustible gas ejected from the tap hole 4 together with the melt. Burns.

[0027]

According to the present invention, the following effects can be obtained.

(1) An economical waste melting furnace can be realized while reliably forming a high-temperature hearth and maintaining a stable tapping of the melt discharged from the high-temperature hearth.

(2) By installing a forehearth and burning the combustible gas spouted from the tap, it is possible to keep the melt at the tip of the tap and to avoid clogging and the like.

(3) By installing a forehearth and forcibly blowing in the combustion air, the surrounding working environment is maintained well, the mixing with the combustible gas is improved, and complete combustion becomes possible. .

[Brief description of the drawings]

FIG. 1 shows the entire structure of a waste melting furnace to which the present invention is applied.

FIG. 2 is an enlarged view of the structure of the forehearth shown in FIG.

FIG. 3 is a front view of FIG. 2 as seen from line AA.

[Explanation of symbols]

Reference Signs List A waste B coke C limestone D blast air E flue gas M melt 1 upper tuyere 2 lower tuyere 3 furnace body 4 tap hole 5 charging cylinder 6 coke charging inlet 7 gas exhaust pipe 8 coke filling area 9 high temperature hearth Area 10 Melting furnace 11 Waste filling area 12 Upper space 13 Secondary combustion chamber 14 Air preheater 15 Gas cooler 16 Dust collector 17 Smoke washing device 18 Induction blower 19 Chimney 20 Ventilation fan 21 Forehearth 22 Flow control valve 23 Air introduction box 24 Nozzle part 25 Exhaust port of forehearth 26 Air header for combustion 27 Nozzle 28 Air introduction pipe 41 Hole of tap hole

 ──────────────────────────────────────────────────続 き Continued on the front page (56) References JP-A-3-5611 (JP, A) JP-A-53-111574 (JP, U) JP-B-41-11038 (JP, B1) JP-B-51- 42433 (JP, B2)

Claims (1)

(57) [Claims] 1. A basicity adjuster and a massive carbonaceous fuel are charged into waste from the top, and combustion gas is blown from a tuyere provided at a lower portion to convert the charged waste into a molten slag to form said wings. In a waste melting furnace for extracting molten material from a tap hole provided below the tap, the tap port is provided laterally on the side of the furnace body.
A forehearth surrounding the tap hole and receiving the extracted melt is formed in the forehearth in an inverted U-shape around the tap hole.
Header with the U-shaped opening facing down,
Waste melting furnace in which a plurality of combustion gas blowing nozzle directed to the tap hole to chromatography.