JP3506608B2 - Dry distillation pyrolysis melting combustion equipment for waste - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a dry distillation pyrolysis / melting combustion apparatus for waste used for melting and burning waste such as municipal waste. The heavy metal of is volatilized by using the heat of combustion of the pyrolysis gas, and by cooling and solidifying the volatilized heavy metal to separate and collect it, the heavy metal content of the granulated slag discharged to the outside is significantly reduced. The present invention relates to a dry distillation pyrolysis melting and combustion apparatus for waste.

[0002]

2. Description of the Related Art The dry distillation pyrolysis melting treatment of waste has an excellent property that harmful substances such as dioxins released to the outside can be reduced, and its development is being promoted in various fields. FIG. 3 shows an example of a conventional dry distillation pyrolysis / melting combustion apparatus for waste, in which the waste C supplied to the dry distillation pyrolysis reactor 2 by the supply device 1 is blocked by air here. At that time, it is heated to a temperature of 300 ° C. to 600 ° C. and converted into a pyrolysis gas G and a pyrolysis residue D.

The pyrolysis products formed inside the dry distillation pyrolysis reactor 2 are separated into pyrolysis gas G and pyrolysis residue D in the carry-out device 3, and the former pyrolysis gas G is melted and burned. It is sent to the device 4 and burned. Further, the latter pyrolysis residue D is sent to the separating device 5 where the relatively coarse non-combustible solid substance N is removed and the fine combustible solid substance I remaining is finely divided in the pulverizing device 6. after being crushed I _O, the fed to the melt combustion apparatus 4, together with the dust E, etc. from the pyrolysis gas G and waste heat boiler 7 and the dust collector 8, 120
It is melted and burned at a temperature of 0 ° C or higher. Further, the molten slag F formed in the melting combustion device 4 is a water granulated slag F ₂
The combustion exhaust gas G _O from the melting combustion device 4 is discharged into the atmosphere through the waste heat boiler 7, the dust collector 8, the gas purification device 9 and the chimney 10.

The dry distillation pyrolysis reactor 2 is composed of a rotary dry distillation drum provided with a heating pipe 11, and waste is put into a plurality of heating pipes 11 arranged in the longitudinal direction of the dry distillation drum. A heating gas K for heating is circulated.
In FIG. 3, 12 is a generator of heated gas K, 13 is a burner, 14 is a steam turbine power generation facility, 15 is a pushing fan, 16 is an induction fan, 17 is a vibration cooler, and 18 is a storage of combustible fine powder. Tank, 19 is a pipe line, 20 is a circulation fan, 21
Is a damper device, 22 is fuel (oil or gas), 23
Is a waste pit, and 24 is a crane.

By the way, the total amount of ash and dust E in the combustible fine powder I _O brought into the melt combustion apparatus 4 does not become the molten slag F in the melt combustion apparatus 4, but
In reality, about 40% of the ash and dust E of combustible fine powder I _O
To a degree, fly ash is transferred into the combustion exhaust gas G _O , and is discharged to the outside of the melting combustion device 4.

On the other hand, combustion exhaust gas G from the melt combustion device 4
The fly ash in _O is collected by the dust collector 8 or the like as described above and returned to the melting and combusting device 4 as the dust E. Therefore, heavy metals such as Pb, Zn, Cd, and Cr contained in the dust E are also melted and combusting device. It will be blown into 4 again. as a result,
The heavy metal concentration in the melting and combustion device will gradually increase, and along with this, the heavy metal concentration in the molten slag F formed in the melting and combustion device 4 will also increase, and the water granulated slag discharged to the outside will be increased. The increased heavy metal content can cause various problems in terms of recycling the granulated slag.

[0007]

DISCLOSURE OF THE INVENTION The present invention has the above-mentioned problems in the prior carbonization pyrolysis / melting combustion treatment of wastes.
That is, it is intended to solve the problem that the heavy metal content of the water granulated slag discharged from the melting and combustion device increases, and the molten slag F is heated in the reducing atmosphere for a predetermined time by using the combustion heat of the pyrolysis gas to By holding the molten metal at a high temperature of 1300 ° C., the heavy metal is volatilized from the inside of the molten slag F, the volatilized heavy metal is discharged together with the combustion gas, and then the solidified water is cooled and solidified to collect water, thereby reducing the water content. It is intended to provide a dry distillation pyrolysis melting and combusting apparatus for waste, which is made into crushed slag.

[0008]

According to the invention of claim 1, the waste is pyrolyzed in a dry distillation pyrolysis reactor to produce a pyrolysis gas and a pyrolysis residue, and the pyrolysis gas and the pyrolysis residue are contained in the pyrolysis gas and the pyrolysis residue. In the dry distillation pyrolysis melting and combusting device of the waste, in which the combustible substance of is melted and burned in the melting and combusting device, and the molten slag from the melting and combusting device is discharged as water granulated slag, The slag pit that receives the molten slag and the molten slag in the slag pit are heated to below the melting temperature.
Burner device for heating to the above temperature and C in the slag pit
CO concentration detection sensor for detecting O concentration and CO concentration detection
Supply to the burner device based on the detection value of the output sensor
Control the amount of combustion air to generate carbon monoxide in the slag pit
To reduce the atmosphere and reduce the evaporation of heavy metals in the molten slag.
And CO concentration control device for promoting a slag cooling water tank receives molten slag and water granulated slag flowing down from the slag pit, the combustion gas by cooling the combustion <br/> gas extracted from within the slag pit Heavy metal volatilized inside
A cooling device for the combustion gas that condenses and solidifies the substances, and a fuel that removes the condensed and solidified heavy metals in the combustion gas from the cooling device.
It is characterized in that a slag treatment device consisting of a burnt gas purifying device is provided to reduce the heavy metal content of the discharged water granulated slag.

According to a second aspect of the present invention, in the first aspect of the invention, the fuel of the burner device is a pyrolysis gas, the cooling device of the combustion gas is a water spray type cooling device, and the combustion gas is purified. The device is a bag filter device, and the combustion gas from the bag filter device, which is attracted by an attracting fan, is supplied to the inside of the melting and combusting device for re-combustion.

According to a third aspect of the present invention, in the first aspect of the invention, the combustion air supplied to the burner device is preheated by the combustion gas extracted from the slag pit.

According to a fourth aspect of the invention, in the second aspect of the invention, the amount of combustion gas attracted from the slag pit by the attraction fan is controlled based on the temperature in the slag pit.
The temperature in the slag pit is adjusted to 1300 ° C to 1 by adjusting the supply amount of the pyrolysis pyrolysis gas supplied to the burner device.
The temperature is kept at 400 ° C.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall system diagram of a waste carbonization pyrolysis melting and combustion apparatus according to an embodiment of the present invention, and FIG. 2 is an overall system diagram of a slag treatment apparatus A forming a main part of the present invention. 1 and 2, the same members as those of the dry distillation pyrolysis melting and combustion apparatus for waste shown in FIG. 3 are designated by the same reference numerals. Also, FIG.
The description of the same members as the constituent members will be omitted.

In FIG. 1 and FIG. 2, reference numeral 4 denotes a melting combustion device.
Reference numeral 4a denotes an outflow passage for the molten slag F, and 4b denotes a high temperature combustion exhaust gas.
G_ODischarge channel, 30 is a slag pit, 31 is a burner
Installation, 32 is a pushing fan, 33 is a heat exchanger, and 34 is combustion
Gas H cooling device, 34a exhaust device, 34b exhaust
Valve, 34c is a storage tank, 35 is a purifying device for combustion gas H, 3
5b is a discharge valve, 35c is a storage tank, 36 is an induction fan, 3
6a is a motor, 37 is a CO concentration controller, 37a is CO
Concentration detection sensor, 38 is temperature control device, 38a is temperature
Detection sensor, 39 slag cooling water tank, 39a slag
Conveyor, 39b is cooling water, 40 is granulated slag F₂Savings
Distillation tank, 41 is the inlet of combustion gas H, G₁・ G ₂Is pyrolysis
Gas, FF₁Is molten slag, F₂Is granulated slag, W is
It is cooling water.

A slag processing device A which constitutes an essential part of the present invention
Is a slag pit 30 for receiving the molten slag F flowing down from the molten combustion device 4, and a burner device 31 for maintaining the molten slag F ₁ in the slag pit 30 at a predetermined temperature.
A cooling device 34 for cooling the combustion gas H extracted from the slag pit 30, a purifying device 35 for removing and recovering the heavy metal contained in the cooled combustion gas H, and an attraction for extracting the combustion gas H in the slag pit 30. Combustion gas H formed of a fan or the like 36 holds the slag pit 30 in a reducing atmosphere to promote volatilization of the heavy metal contained in the molten slag F ₁ and also contains a volatile gas of the heavy metal.
Is extracted from the slag pit 30, and the heavy metal in the combustion gas H condensed and solidified by cooling in the cooling device 34 is recovered and removed in the combustion gas purifying device 35.

The slag pit 30 is provided below the molten slag outflow passage 4a of the molten combustion apparatus 4, and receives the molten slag F flowing down through the outflow passage 4a.
A burner device 31 is provided on the ceiling of the slag pit 30, and the molten slag F in the slag pit 30 is
₁ is about 1300 ℃ due to the combustion heat of the burner device 31
The temperature is kept around.

A part G ₁ of the pyrolysis gas G is supplied to the burner device 31 as a fuel. In the present embodiment shown in FIGS. 1 and 2, the temperature control device 38 will be described later. The amount of suction of the pyrolysis gas G ₁ to the burner device 31 is adjusted by controlling the amount of induction air of the induction fan 36 by this, whereby the temperature of the molten slag F ₁ in the slag pit 30 is adjusted to about 1300. Hold at ℃. Needless to say, the type of fuel supplied to the burner device 31, the fuel supply method, the supply amount control method, the slag pit temperature control method, and the like may be any method.

Combustion air a of the burner device 31 is supplied by a pushing fan 32 and a heat exchanger 33.
The air a preheated by the combustion gas H from the inside of the slag pit 30 is supplied. Further, the supply amount of the combustion air a is controlled by the CO concentration control device 37.
By controlling the air flow rate of 2, the inside of the slag pit 30 is adjusted so as to always have a reducing atmosphere.

It should be noted that the inside of the slag pit 30 is about 1300 ° C.
The high temperature reducing atmosphere of 1400 ° C. is maintained because Pb, Zn, Cd, Cr and the like contained in the molten slag F ₁ are easily volatilized and vaporization of heavy metals is accelerated. Further, in FIGS. 1 and 2, the CO concentration control device 37 changes the supply amount of the combustion air a to keep the inside of the slag pit 30 in the reducing atmosphere. Any method may be used for maintaining the reducing atmosphere in the reducing atmosphere.

The combustion gas H generated in the slag pit 30 by the operation of the burner device 31 contains a large amount of the volatile gas of the heavy metal in the molten slag F ₁ as described above. The combustion gas H containing a large amount of heavy metal volatile gas is
It is extracted from the slag pit 30 by the operation of the induction fan 36 and introduced into the cooling device 34 through the heat exchanger 33.

In the present embodiment, a water spray type cooling device is used as the cooling device 34, and the combustion gas H is brought into contact with the sprayed cooling water W at about 1300 ° C. to 1 ° C.
It is cooled from a high temperature of 400 ° C to a temperature of about 160 ° C. Further, the heavy metal gas in the combustion gas H is condensed and solidified by the contact with the spray water W, and a part of the heavy metal gas is discharged to the outside through the discharge device 34a and the discharge valve 34b together with the cooling water W, and is discharged to the storage tank 34c as a discharge product Wa. Be recovered.

In the embodiment shown in FIGS. 1 and 2,
Although a water spray type cooling device is used, any other cooling device for the combustion gas H may be used, and for example, a waste heat boiler may be used.

The combustion gas H cooled by the cooling device 34 is continuously introduced into the combustion gas purifying device 35, where the solidified heavy metals and other impurities remaining in the combustion gas H are recovered and removed. Further, the removed heavy metal and other impurities Wb are recovered into the storage tank 35c through the discharge valve 35b.

In the present embodiment, a bag filter device is used as the purifying device 35 for the combustion gas H. While the combustion gas H is passing through the bag filter by the induction fan 36, condensed solid heavy metals and the like are removed. Collected in the filter material on the outer surface of the bag. Further, the combustion gas H purified by passing through the bag filter is continuously ejected inward from the combustion gas supply port 41 provided in the melting combustion device 4 through the pipe line 42, where it is injected into the combustion gas H. CO remaining
Is burned. The combustion gas H extracted from the reducing slag pit 30 contains a large amount of CO,
In addition, these CO are the cooling device 34 and the bag filter device 3.
This is because 5 is not enough to remove it.

Further, in this embodiment, the bag filter device 3 is used.
The high-concentration combustion gas H from 5 is re-combusted in the melting combustion device 4, but when the emission amount of the combustion gas H is small, CO is chemically removed, and then it is released into the atmosphere. Of course, it may be released. Further, in this embodiment, a part G ₁ of the pyrolysis gas G from the dry distillation pyrolysis reactor 2 is supplied to the burner device 31 as it is.
The pyrolysis gas G ₁ may be supplied to the burner device 31 after being brought into contact with a dehydrochlorination treatment agent such as slaked lime to perform dehydrochlorination treatment. By subjecting the pyrolysis gas G ₁ to the dehydrochlorination treatment, the concentration of hydrogen chloride gas in the combustion gas H is reduced to a negligible level, and the heat exchanger 33
It is possible to prevent the occurrence of high-temperature corrosion in such cases.

[0025]

According to the present invention, the molten slag F flowing out of the melting and combustion apparatus is kept at a temperature of about 1300 ° C. for a certain period of time in the slag pit 30 kept in a reducing atmosphere, and the molten slag F ₁ is kept in the molten slag F ₁ . The heavy metal is volatilized, and the combustion gas H in the slag pit 30 containing the volatile gas is cooled and purified to recover the heavy metal. as a result,
The heavy metal in the molten slag F ₁ discharged from the slag pit 30 is significantly reduced, and the granulated slag F ₂ discharged to the outside is discharged.
The heavy metal content of is also reduced, making recycling easier.
In addition, the recovered heavy metal can be reused, which is advantageous in terms of effective use of resources. Furthermore, 30 slug pits
When the pyrolysis gas G ₁ is used as the fuel for the burner device 31 of FIG. ₁ , more effective utilization of waste energy can be achieved, and the cost of heavy metal removal treatment of slag can be reduced. In addition, when the pyrolysis gas subjected to the dehydrochlorination treatment is used as the fuel of the burner device 31, the concentration of hydrogen chloride in the combustion gas H from the slag pit 30 is reduced, and the heat exchanger 33 and the like are cooled. It is possible to prevent the occurrence of high temperature corrosion. INDUSTRIAL APPLICABILITY As described above, the present invention can efficiently and significantly reduce the heavy metal in the water granulated slag discharged from the dry distillation pyrolysis / melting combustion device of waste to a large extent, and has an excellent practical utility. It plays.

[Brief description of drawings]

FIG. 1 is an overall system diagram of a dry distillation pyrolysis melting and combustion apparatus for waste according to an embodiment of the present invention.

FIG. 2 is an overall system diagram of a slag processing device showing a main part of the present invention.

FIG. 3 is an overall system diagram of a conventional dry distillation pyrolysis melting and combustion apparatus for waste.

[Explanation of symbols]

A ... slag treatment device, C ... waste, D ... thermal decomposition residue, E
… Dust, FF₁… Molten slag, F₂… Granulated slag,
GG₁・ G₂… Pyrolysis gas, I… Combustibles, I _O... flammable
Fine powder, G_O… Combustion exhaust gas, H… Combustion gas, a… Combustion sky
Air, W ... Cooling water, Wa / Wb ... Emissions, 2 ... Pyrolysis pyrolysis
Reactor, 3 ... Carrying out device, 4 ... Melting combustion device, 4a ... Melting
Slag outflow passage, 4b ... High temperature combustion exhaust gas discharge passage, 5 ... min
Separator, 6 ... Crusher, 7 ... Waste heat boiler, 8 ... Dust collector,
9 ... Gas purifier, 30 slag pit, 31 ... Burner
Placement, 32 ... Pushing fan, 33 ... Heat exchanger, 34 ... Combustion
Gas cooling device, 35 ... Combustion gas purification device, 36 ... Invitation
Draw fan, 37 ... CO concentration control device, 38 ... Temperature control device
39, slag cooling water tank, 40 ... granulated slag storage tank,
41 ... Combustion gas inlet.

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B09B 3 / 00,5 / 00 F23G 5/027

Claims (4)

(57) [Claims] 1. A pyrolysis gas and a pyrolysis residue are generated by pyrolyzing a waste material in a dry distillation pyrolysis reactor, and the pyrolysis gas and a combustible material in the pyrolysis residue are melted and burned in a melting combustion device. In addition, in the dry distillation pyrolysis melting and combusting device of the waste so that the molten slag from the melting and combusting device is discharged as granulated slag, a slag pit that receives the molten slag from the melting and combusting device, and a slag pit Molten slag in
A burner device that heats the
CO concentration detection sensor for detecting CO concentration in lag pit
And the value based on the detection value of the CO concentration detection sensor.
The slag pit is controlled by controlling the amount of combustion air supplied to the
The inside of the molten slag is made into a reducing atmosphere with carbon monoxide.
And CO concentration control device for promoting the volatilization of heavy metals, and slag cooling water tank to water granulated slag accept molten slag flowing down from the slag pit, combustion by cooling the combustion gas extracted from within the slag pit In gas
A cooling device for the combustion gases the heavy metals condense solidified volatilized to heavy condensed solidified in the combustion gas from the cooling device
A dry distillation pyrolysis melting and combustion apparatus, characterized in that a slag treatment device comprising a combustion gas purifying device for removing metal is provided to reduce the heavy metal content of discharged granulated slag. 2. A bag filter in which a burner device uses pyrolysis gas as fuel, a combustion gas cooling device as a water spray type cooling device, and a combustion gas purification processing device as a bag filter device, which is attracted by an induction fan. The combustion gas from the apparatus is supplied into the melting combustion apparatus for re-combustion.
Pyrolysis pyrolysis melting combustion equipment of waste according to. 3. The waste carbonization pyrolysis / melting combustion apparatus according to claim 1, wherein the combustion air supplied to the burner unit is preheated by the combustion gas extracted from the slag pit. 4. The slag is controlled by controlling the amount of combustion gas attracted from the inside of the slag pit by the attracting fan based on the temperature inside the slag pit, and adjusting the amount of carbonization pyrolysis gas supplied to the burner device. The temperature in the pit is 130
The dry distillation pyrolysis melting combustion apparatus for waste according to claim 2, wherein the apparatus is kept at 0 ° C to 1400 ° C.