WO2010086966A1

WO2010086966A1 - Fusing apparatus for fibrous silicate mineral

Info

Publication number: WO2010086966A1
Application number: PCT/JP2009/051335
Authority: WO
Inventors: 清治道前
Original assignee: Michimae Kiyoharu
Priority date: 2009-01-28
Filing date: 2009-01-28
Publication date: 2010-08-05
Also published as: JPWO2010086966A1; JP4410843B1

Abstract

Provided is a fusing apparatus which can perform fusion detoxification processing of a fibrous silicate mineral such as asbestos safely, stably and efficiently. The fusing apparatus for fibrous silicate minerals comprises a shaft furnace type primary fusing furnace having a section for throwing in a matter to be processed at an upper part, and a burner for irradiating flame into the furnace from a lateral side at a lower part, and a secondary fusing chamber performing fusion processing of powdery matter produced in the primary fusing furnace, and is further provided with a heat exchanger for controlling outer air to hot wind of 700-1000°C by using combustion gas collected from the secondary fusing chamber. The temperature in the primary fusing furnace is controlled to 1700-1900°C by blowing the hot wind of 700-1000°C into the burner of the primary fusing furnace.

Description

Fibrous silicate mineral melting equipment

The present invention relates to a melt processing apparatus for melting and detoxifying fibrous silicate minerals collectively called asbestos.

Naturally produced mineral fibers are collectively referred to as asbestos. Specific examples include serpentinite chrysonyl (white asbestos), amphibolite crocidolite (blue asbestos) and amosite (tea asbestos). It is done.
Asbestos has been widely used all over the world because of its excellent industrial properties such as heat resistance, chemical resistance, and insulation properties. forbidden.

However, since fibrous minerals such as asbestos contain water of crystallization, etc., when the ambient temperature reaches 500 to 1000 ° C., dehydration proceeds and the crystal structure collapses to become powdery. If this powdered material is scattered, there is a high risk of generating secondary pollution, and detoxification is difficult.
More specifically, when the fibrous mineral melts, it becomes a molten ingot with a specific gravity of about 4000 kg / m ³ , but in the fibrous state, the specific gravity is very light, about 100 kg / m ^3, so asbestos is simply melted at high temperature. However, there is a problem that the entanglement phenomenon occurs without the mineral fibers being fused and scattered as a powdery material, and the actual situation is that an apparatus capable of completely detoxifying asbestos has not been realized.

An object of the present invention is to provide a melt treatment apparatus that can safely and stably perform fibrous detoxification treatment on fibrous silicate minerals such as asbestos.

The apparatus for melting a fibrous silicate mineral according to the present invention is a shaft furnace type primary melting having an input portion for an object to be processed at the upper portion and a burner device for irradiating a flame from the lower side portion into the furnace. A secondary melting chamber for melting the powder generated in the primary melting furnace and controlling the outside air to hot air of 700 to 1000 ° C. using the combustion gas recovered from the secondary melting chamber A heat exchanger is provided, and the temperature in the primary melting furnace is controlled to 1700 to 1900 ° C. by blowing hot air of 700 to 1000 ° C. into the burner device of the primary melting furnace.

A temperature of 1350 to 1500 ° C. is the limit of the temperature that can be obtained in a stable manner by simply placing a fibrous silicate mineral material into a shaft furnace type melting furnace and heating it with a burner combustion flame. .
Therefore, in the present invention, hot air obtained by heating outside air to 700 to 1000 ° C. is blown into the burner apparatus.
As a result, the temperature of the burner combustion flame can be increased to about 2000 ° C., and the temperature in the primary melting furnace can be controlled to a high temperature of 1700 to 1900 ° C.
In order to blow hot air into the burner, the blowing pressure is preferably 300 to 700 mmAq.

When the burner apparatus is used to irradiate the object to be processed, which is introduced into the furnace from the lower side of the primary melting furnace, the object to be processed is heated.
Asbestos and other objects to be treated are thrown into containers and stored and transported to prevent scattering, so waste plastics are often mixed in, so gas is also generated from plastics. .
Accordingly, when the object to be treated is heated together with the container, a flammable waste gas and a part of asbestos in powder form are generated in addition to the magmatic melt.

Therefore, in the present invention, a secondary melting chamber (secondary combustion chamber) is provided in which the gas generated in the primary melting furnace is subjected to secondary combustion and the powder generated in the primary melting furnace is melted into droplets. It was.
If the secondary melting chamber is kept at 1600 ° C. or higher, the powdered material becomes molten droplets.
Moreover, you may provide the auxiliary combustion burner for burning the gas emitted from plastics.

In the present invention, the input portion of the object to be processed in the primary melting furnace has a double door structure including a primary door on the side for receiving the object to be processed accommodated in the container and a secondary door on the side to be input into the furnace. It may be an input chamber.
In addition, the heat exchanger includes a primary heat exchanger that lowers the combustion exhaust gas temperature to about 1300 ° C., a secondary heat exchanger that lowers the combustion exhaust gas temperature to about 900 ° C., and a tertiary heat exchanger that drops the temperature to about 800 ° C. or less. It is also possible to obtain a hot air of 700 to 1000 ° C. by taking outside air as a refrigerant of the heat exchanger.
Combustion exhaust gas whose temperature has been lowered to about 800 ° C. or less by a heat exchanger can be effectively used using a waste heat boiler or the like, and thereafter, a conventional exhaust gas treatment means that passes through a bag filter or the like is used. be able to.
Moreover, you may employ | adopt a water cooling jacket structure so that the furnace wall of a primary melting furnace and a secondary melting chamber can endure high temperature.

Since the melt processing apparatus in the present invention can melt the powder generated at the time of melting in the secondary melting chamber in the case of detoxifying asbestos, the asbestos can be completely detoxified and safe. Stable operation.
In addition, the combustion air is used to heat and heat the outside air with a heat exchanger, and this hot air is blown into the burner device of the primary melting furnace to obtain a high-temperature frame and change the hot air temperature to 600 to 1000 ° C. The frame temperature can be variably controlled to about 1620-2000 ° C.

The flowchart of the melt processing apparatus which concerns on this invention is shown. The enlarged view of a heat exchanger is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Primary melting furnace 11 Burner apparatus 12 Primary door 13 Secondary door 14 Pusher 15 Extraction door 20 Secondary melting chamber 21 Recovery cylinder 22 Conveyor 23 Auxiliary burner 24 Blower 30 Primary heat exchanger 31a, 3ab Secondary heat exchanger 32 Tertiary heat exchanger

The structural example of the fusion processing apparatus of the fibrous silicate mineral which concerns on this invention is demonstrated based on drawing below.
FIG. 1 shows a flow diagram of recovered combustion gas accompanying the process from an asbestos stored in a storage room to a harmless melt as an example of a treatment target.
Asbestos is a cause of pollution if it is not reliably prevented from being scattered, so it is stored in a container 4 sealed from the collection site, and stored in a storage room 1 that is carried in and sealed by a truck or the like.
The container 4 carried in from the loading platform such as a truck using the lifter 3 is charged into the primary melting furnace 10 from the charging portion disposed at the upper part of the primary melting furnace 10 by the conveyor 2b.
The primary melting furnace 10 is a vertical shaft furnace type, and an object to be processed is introduced into the furnace from an upper charging part and is processed by a combustion frame of a burner device 11 provided on a lower side part. Heat.
The charging section of the primary melting furnace 10 has a double door structure including a primary door 12 on the side to receive the workpiece 5 while being accommodated in the container 4 and a secondary door 13 on the side to be charged into the furnace. It is chamber 18.
When the container 4 is charged into the charging chamber 18, the primary door 12 is opened by the operation of the cylinder 12a or the like with the secondary door 13 closed.
When the container 4 is charged into the charging chamber 18, the primary door 12 is closed, then the secondary door 13 is opened by the operation of the cylinder 13 a and the like, and the container 4 is pushed into the furnace 19 by the pusher 14.
When the container 4 falls into the furnace, the secondary door 13 is closed.

When the container 4 is put into the furnace 19, it is heated by the burner device 11 provided on the lower side portion of the primary melting furnace 10.
The burner device 11 is supplied with auxiliary combustion air by the compressor 16 and hot air A4 of about 700 to 1000 ° C. heated by a heat exchanger described later.
For example, the melting point of chrysotile is 1521 ° C., and 1600 ° C. or higher is preferable for melting mixed asbestos.
Therefore, the flame temperature can be raised to 1900 to 2000 ° C. by blowing heated hot air into the burner device.
Here, when hot air is blown at a pressure of 300 to 700 mmAq, if the hot air temperature is raised from 700 ° C. to 1000 ° C., the flame temperature changes from 1700 ° C. to 1900 ° C. or higher, so the temperature of the hot air to be blown is controlled. Thus, the furnace temperature can be managed.

In the primary melting furnace, approximately three layers are formed: a molten layer M, a dry oil layer C on which waste plastic or the like is gasified, and a dry layer D in which minerals are dried and decomposed thereon.
The molten layer M melted in a magma shape is recovered as a solid melt 15a by opening the extraction door 15 provided near the bottom of the furnace.

The powdery substance generated from the dry layer D and the combustible gas generated from the dry oil layer C are fed into the secondary melting chamber 20.
Reference numeral 17 in the figure denotes an analyzer.
The secondary melting chamber 20 is maintained at about 1550 to 1650 ° C. by the blower 24 and the auxiliary burner 23.
In the secondary melting chamber 20, the combustible gas generated in the primary melting furnace 10 burns, the asbestos powder is melted and dropped, flows down along the collection cylinder 21, and becomes solid on the conveyor 22 or the like. To be recovered.

The combustion gas generated in the secondary melting chamber 20 is guided to the heat exchanger as the recovered combustion gas 33.
The heat exchanger is divided into three stages of a primary heat exchanger 30, a

secondary heat exchange

31a, 31b, and a tertiary heat exchanger 32 according to the temperature range.
The enlarged schematic diagram is shown in FIG.
The primary heat exchanger 30 lowers the recovered combustion gas 33 to about 1300 ° C., and the

primary heat exchangers

31a and 31b lower the recovered combustion gas 33 from about 1300 ° C. to about 900 ° C. The vessel 32 is lowered to about 800 ° C. or less and then sent to, for example, the waste heat boiler 40 and used for waste heat utilization.
Thereby, the air A1 of the outside air sent to the tertiary heat exchanger 32 by the blower 34 becomes hot air A2 heated from 20 ° C. to about 240 ° C., and is about 800 ° C. in the

secondary heat exchangers

31a and 31b. Is heated to about 1000 ° C. by the primary heat exchanger 30 and supplied to the burner device 11 of the primary melting furnace 10.

A structural example of the heat exchanger will be described with reference to FIG.
In FIG. 2, an arrow indicated by a double line indicates a flow of the recovered combustion gas 33, and a white arrow indicates a large flow of hot air.
A thin solid line arrow indicates the flow of air in the heat exchange material, and a dotted line arrow indicates the flow of hot air in the primary to tertiary heat exchangers.
Since the primary heat exchanger 30 is intended for the high-temperature recovered combustion gas 33 of about 1450 to 1300 ° C., the heat exchanger 30a made of a ceramic material is used.
The heat exchanger material 30a can be thermally expanded and contracted without being restrained in the vertical direction so as to withstand a temperature difference.
Since the

secondary heat exchangers

31a and 31b target the recovered combustion gas at about 1300 ° C. to 900 ° C., the heat exchange material 31c in which the outer peripheral portion is made of a ceramic material and the metal material is arranged on the inner peripheral side is used. .
In addition, the heat exchange pipe made of a metal material has a double structure of the outside and the inside, and the inside heat exchange pipe 31e has a hanging structure in which the lower end portion is free.
Since the tertiary heat exchanger 32 has a relatively low temperature of about 900 to 800 ° C., it is composed of a metal double-structure

heat exchange pipe

32a, 32b, and the inner heat exchange pipe 32b has a lower end portion. It has a free hanging structure.
In addition, the code | symbol S in a figure shows the partition wall of collection | recovery combustion gas and heating air.

The recovered combustion gas 33 that has passed through the tertiary heat exchanger 32 may be used as waste heat in a waste heat boiler 40 or the like, as shown in FIG. 1, and the waste heat boiler 40 may be used for power generation. it can.
Further, the exhaust gas after use of heat is neutralized using a slaked lime tank 60 and a spray device 61 as necessary, passes through the bag filter 50, and is discharged from the chimney 53 to the atmosphere by the exhaust gas blower 51.
In that case, it is checked by the exhaust gas analyzer 54.
The residue collected by the bag filter 50 is opened and collected by the conveyor 50b by opening the valve 50a.

In the present invention, hot air is produced by a heat exchanger using a combustion gas as a heat source, and this hot air is blown into a burner device, so that a high temperature of 1600 ° C. or higher, which has been difficult in the past, can be achieved. It is possible to drop the powdery material generated in step 2 in the secondary melting chamber, and it is suitable for detoxifying high melting point fibrous minerals.

Claims

A shaft furnace type primary melting furnace having a burner device that has an input part of an object to be processed in the upper part and flame irradiation into the furnace from the lower side part;
A secondary melting chamber for melting the powder generated in the primary melting furnace,
Having a heat exchanger that controls the outside air to hot air of 700 to 1000 ° C. using the combustion gas recovered from the secondary melting chamber;
An apparatus for melting a fibrous silicate mineral, wherein the temperature in the primary melting furnace is controlled to 1700-1900 ° C. by blowing the hot air of 700-1000 ° C. into the burner device of the primary melting furnace. .
The input part of the workpiece of the primary melting furnace is a double door structure input chamber composed of a primary door on the side for receiving the object to be processed contained in the container and a secondary door on the side to be input into the furnace. The apparatus for melting a fibrous silicate mineral according to claim 1, wherein:
The heat exchanger includes a primary heat exchanger that lowers the flue gas temperature to about 1300 ° C., a secondary heat exchanger that lowers the temperature of the exhaust gas to about 900 ° C., and a tertiary heat exchanger that drops the temperature to about 800 ° C. or less. The fusion treatment of fibrous silicate mineral according to claim 1, which is a three-stage heat exchanger, and takes in air from outside as refrigerant of the heat exchanger to obtain hot air at 700 to 1000 ° C. apparatus.