JPH0772608B2 - Waste combustion and melting equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste combustion and melting apparatus, and more particularly to a coal-fired boiler, kiln, coal ash discharged from an industrial furnace, municipal waste, sewage sludge, and general waste. It is a device that melts and solidifies wastes or wastes such as incineration ash at high temperature, and solidifies the wastes, detoxifying the energy, reusing the solidified materials for building materials, etc. The present invention relates to a possible combustion melting device.

[0002]

2. Description of the Related Art In recent years, in industrial furnaces such as boilers, kilns, and heating furnaces, conversion from oil or gas fuel to coal fuel has been actively promoted from the viewpoint of reducing fuel cost. With the increase in the amount of coal fuel used, the amount of coal ash remaining after combustion of the coal fuel is also increasing year by year, and it is necessary to treat the coal ash.

Conventionally, most of the above-mentioned coal ash treatment methods are used for landfill treatment.
Some are effectively used as admixtures for building cement. In addition, municipal waste, sewage sludge, etc., and incinerator ash discharged from those incinerators are all disposed of by landfill.

However, in recent years, it has become difficult to secure landfill sites for the above-mentioned coal ash and incinerated ash, and the disposal standards are strict from the viewpoint of preventing marine pollution by harmful substances, resulting in high cost management. It is becoming a landfill and it is difficult to use the landfill treatment. Therefore, post-treatment of waste such as coal ash and incineration ash has become a very important issue today.

From this point of view, the present applicant has filed Japanese Patent Application No. 62-1
87453 and Japanese Patent Application No. 62-187454 proposed a device for melting and solidifying ash. These devices are, for example, as shown in FIG. 2, which is characterized in that coal ash and incineration ash are mixed in advance with combustion air, and the mixed solid-gas two-phase flow is swirled in the furnace. It is at the point that it is solidified after being jetted out and melted. The details will be described below with reference to FIG.

That is, the inside of the furnace 1 and the furnace wall are heated by the main burner 2 provided in the upper part of the swirling flow melting furnace 1, and the temperature is maintained at a temperature higher than the temperature at which the ash melts and can flow down. At this time, in order to burn the fuel ejected from the burner 2, combustion air is blown from the pipes 9 and 10. Pipe 10
Are arranged so that the direction of injection of combustion air is tangential to the furnace wall when viewed from above. Then, the ash in the hopper 3 is quantitatively cut out by the table feeder 4, dropped into the pipe 9 through the valve 5, mixed into the combustion air flowing in the pipe 9, and blown into the furnace 1 together with the air. . In this way, a solid-gas two-phase flow composed of ash and air is generated in the furnace 1.
The ash is melted and turned into slag by being heated while swirling on the furnace wall inside.

[0007] The molten slag S flows down along the furnace wall, passes through the narrowing portion 7, falls to the inclined portion of the slag portion 8, flows down along the inclined portion, and the vertical portion of the slag portion 8 From insulation hood
After passing through 20 openings, it flows into the mold 13 and is conveyed by the conveyor 14 together with the mold 13. During the transportation, the molten slag is cooled and solidified into solidified slag C, which is dropped into the solidified slag container 16 and collected.

Further, JP-A-63-70014 and JP-A-63-700.
No. 15 discloses a cyclone-type sewage sludge incinerator / melting furnace for treating granulated and dried sewage sludge. A plurality of blow ports for tangentially feeding into the furnace are provided near the preheating burner.

[0009]

The above-mentioned conventional technique is capable of stable melting when the waste disposal capacity is relatively small. That is, the processing capacity of dehydrated cake is 50 tons /
For small furnaces up to a day (ash processing capacity of about 8 tons / day),
Since the heat loss of the furnace body and the sensible heat of the exhaust gas are large, the unit preheating burner fuel unit (Kcal / cake Kg) is large, resulting in a large amount of air per unit weight of waste, and the concentration of waste in the furnace space. Is at a low level.

However, if the dehydration cake treatment capacity: 50 tons / day (ash treatment capacity: about 8 tons / day) or more is attempted to be processed by the conventional technique, the unit heating unit for preheating burner fuel will be greatly improved. Therefore, the concentration of waste in the furnace becomes extremely high. Therefore, the temperature of the furnace top is lowered, and the waste adheres to the furnace wall in a semi-molten state, gradually grows, is clogged, and cannot be dissolved. That is, if there is a waste material with a large heat absorption amount in the vicinity of the preheating burner, the flame temperature is extremely lowered, and the mixing of the fuel of the preheating burner and the combustion air is suppressed to cause a combustion delay and the melting becomes impossible. .

Further, as described above, since the concentration of the waste in the furnace is high, the light emitted from the flame is attenuated, sufficient light does not reach the flame detector, a misfire signal is issued, and combustion is cut off. There is a problem that it becomes impossible to melt.

The present invention has been made in order to solve the above problems, and its purpose is to generate a high temperature combustion gas when melting and solidifying this kind of waste, and to dispose of it. By arranging the area for melting an object by contacting it with high-temperature combustion gas and melting it in a melting furnace, it is possible to completely melt the waste even when the throughput of the waste is relatively large. The aim is to increase the processing capacity and to achieve a stable combustion and melting process.

[0013]

In order to achieve the above object, the waste combustion and melting apparatus according to the present invention has the following configuration. That is, the waste combustion / melting apparatus according to claim 1 has a combustion zone in the upstream portion where the fuel supplied from the burner and the combustion air are mixed and burned to generate high temperature combustion gas. And a combustion melting furnace having a melting zone in the downstream portion for melting the waste supplied from the supply hole by the high temperature combustion gas from the combustion zone, and combusting and melting the waste by the combustion melting furnace. A waste combustion melting device, wherein the burner is installed on the top wall of the combustion melting furnace.
While it is set, a combustion melter waste characterized by being 0.5 to 1.5 times the inner diameter of the combustion zone the length of the combustion zone of the combustion melting furnace.

A waste combustion and melting device according to claim 2
The waste combustion melting apparatus according to claim 1, wherein an annular partition is provided between the combustion zone and the melting zone, and the partition has a flow passage having an inner diameter of 0.6 to 0.9 times the inner diameter of the combustion melting furnace.

[0015]

As described above, the waste combustion / melting apparatus according to the present invention has, in the upstream portion, the combustion zone in which the fuel supplied from the burner and the combustion air are mixed and burned to generate high temperature combustion gas. the waste to be fed from the feed holes comprising a waste feed holes comprising a combustion melting furnace comprising a downstream portion of the melting zone for melting by hot combustion gases from the combustion zone, combustion soluble
Combustion-melting equipment for waste that burns and melts waste with a melting furnace
And the burner is disposed on the top wall of the combustion melting furnace.
While being made to the length of the combustion zone of the combustion melting furnace to 0.5-1.5 times the inner diameter of the combustion zone. Burning like this
The upstream part of the melting furnace is a combustion zone, and the combustion zone is used for fuel and combustion.
The burner that supplies air is the combustion melting furnace top wall or furnace top.
It is installed at the position corresponding to the upstream part of the combustion zone,
It is sufficient that the length of the zone is 0.5 to 1.5 times the inner diameter of the combustion zone.
Long, the combustion zone is burned with the fuel supplied by the burner.
Combustion air is mixed and burned to produce good high temperature combustion gas.
A combustion zone that has the function to generate (high temperature combustion gas generation function)
It On the other hand, the downstream part of the combustion melting furnace is a melting zone,
The strip is equipped with waste feed holes (ie melt zone location
(There is a waste supply hole in the side wall of the combustion melting furnace)
Therefore, the melting zone is designed to remove the waste supplied from the waste supply hole.
Function of melting by high temperature combustion gas from the combustion zone
It becomes a melting zone having (waste melting function). Therefore,
Combustion zone with such high temperature combustion gas generation function and waste melting
The melting zone having the melting function is respectively the upstream part of the combustion melting furnace.
It is located in the downstream part and is separated in the combustion melting furnace.
Therefore, the combustion zone and the melting zone are functionally separated from each other.
Will be. In other words, the waste supply holes are
Not in the burner section of the combustion zone upstream of the furnace, but in the burner section.
The high temperature combustion gas (waste
The space concentration is extremely low and the temperature does not easily drop.
Form a combustion zone that can generate retained hot gases)
Of the downstream of the combustion melting furnace at a position sufficient to
Since it is in the melting zone, the combustion zone and the melting zone are located inside the combustion melting furnace.
Exists in the combustion zone and has excellent high temperature combustion gas production.
It has a function of melting and one of the melting zones has a function of melting waste.
Will be. From the above, in the combustion zone, there is almost no waste and the space concentration of the waste is extremely low, so that the high temperature combustion gas generated is less likely to decrease in temperature and is kept at a high temperature. This hot combustion gas flows down into the melting zone where it completely melts the waste. Therefore, adhesion of the semi-molten material to the furnace wall is unlikely to occur, blockage can be prevented, and combustion delay does not occur. Therefore, it is possible to completely melt the waste even when the amount of the waste treated is relatively large.
The processing capacity can be enhanced, and a stable combustion and melting process can be realized. Furthermore, since the spatial concentration of the waste in the combustion zone is extremely low as described above, the light emitted from the flame is less likely to be attenuated, so that the occurrence of combustion interruption due to the misfire signal of the flame detector can be prevented. Become.

The length of the combustion zone of the combustion melting furnace is set to 0.5 to 1.5 times the inner diameter of the combustion zone in order to generate good high temperature combustion gas as described above in the combustion zone and To prevent the size from increasing ,
What is the length of the combustion zone with respect to the diameter and the generation state of hot combustion gas
There is a close relationship, and the length of such combustion zone is determined by the inner diameter of the combustion zone.
If it is less than 0.5 times, good high temperature combustion gas generation is hindered, combustion delay occurs, and combustion becomes unstable.
On the other hand, if it is 0.5 times or more, good high temperature as above
Although it is possible to produce a combustion gas, combustion in 1.5 fold
As the smelting and melting furnace becomes larger and larger, the furnace wall area increases and heat loss increases, which in turn causes economic deterioration.
Because it will be . In other words, the length of the combustion zone is
Combustion melting by 0.5 to 1.5 times the inner diameter
Do not cause problems such as increased heat loss due to the size increase of the furnace.
In addition, it is possible to generate good high temperature combustion gas as described above.
On the other hand, if it is less than 0.5 times,
It becomes impossible to generate good high temperature combustion gas,
When it exceeds 1.5 times, the heat loss due to the larger size of the combustion melting furnace
This is because it leads to problems such as increased losses. still,
The state of generation of high-temperature combustion gas depends on the combustibility of the fuel or the flame length.
Including this, the length of the above combustion zone is detected.
Has been debated and set.

That is, in the present invention, the combustion zone is composed of fuel and 1
This is a region where the secondary combustion air is mixed and burned, and as the fuel, gas fuel such as natural gas, propane gas, butane gas, liquid fuel such as heavy oil and kerosene, and solid fuel such as coal are used. These fuels have different combustibility and different flame lengths. In general, gas fuel, liquid fuel,
Combustibility is poor in the order of solid fuel, and flame tends to be long. Therefore, it is necessary to set the combustion zone length according to the flammability or flame length.

In setting the combustion zone length, considering that the high-temperature combustion gas is supplied (flowed down) to the melting zone and the waste is melted in the melting zone, the combustion zone is designed to completely burn the fuel in the combustion zone. It is best to set the length, but in consideration of the important compaction of the combustion melting furnace, in the combustion zone
It is practical to set the combustion zone length so that 50% or more of the fuel burns. The practical combustion zone length should be 0.5 to 1.0 times the inner diameter of the combustion zone when using gas fuel with good combustibility, and then 0.8 for liquid fuel.
~ 1.2 times, and for solid fuel, 1.0 to 1.5 times. Therefore, the length of the combustion zone is set to 0.5 to 1.5 times the inner diameter of the combustion zone in order to adapt it to the use of either gas fuel, liquid fuel or solid fuel.

[0019] The annular partition wall between the melting zone and the combustion zone is provided, if the partition wall to have a flow path of 0.6 to 0.9 times the inner diameter of the combustion melting furnace inside diameter, high-temperature combustion to the molten zone from the combustion zone
It is possible to prevent the waste gas supplied to the melting zone and the melt generated in the melting zone from flowing back into the combustion zone without obstructing the flow of the combustion gas, and therefore the spatial concentration in the combustion zone can be constantly lowered. Therefore, it is possible to more reliably generate the hot combustion gas, and
It is possible to prevent the occurrence of combustion interruption due to the misfire signal of the flame detector, and it is possible to further stabilize the combustion melting process. Therefore, it is desirable to provide such a partition. In contrast,
If the flow path diameter of the partition wall exceeds 0.9 times the inner diameter of the melting furnace , the partition wall
The difference between the flow path diameter and the melting furnace inner diameter is small,
The function of the partition to prevent backflow to the combustion zone is demonstrated.
However , the above-mentioned effects are small, and if it is less than 0.6 times.
The flow path diameter of the partition becomes too small with respect to the inner diameter of the melting furnace.
Rutotomoni stream of hot combustion gases into the melt zone is inhibited from the combustion zone by a partition wall, pressure loss increases, Ri swirling flow Yowama, pull
It becomes difficult to completely melt the waste in the melting zone,
Complete melting of materials, enhancement of processing capacity and realization of stable melting processing
It tends to be difficult to achieve the object of the present invention. Obey
When the partition wall is provided, the partition wall is in the combustion melting furnace.
It is recommended to have a flow passage with an inner diameter of 0.6 to 0.9 times the diameter.
Good. In other words, when the partition wall as described above is provided, the partition wall
If the flow path diameter is set to 0.6 to 0.9 times the inner diameter of the combustion melting furnace,
When the flow of hot combustion gas from the burning zone to the melting zone is obstructed
Wastes and melts as described above without causing such problems
It is possible to prevent the backflow of fuel into the combustion zone.
However, when it exceeds 0.9 times, it goes to the combustion zone of waste and melt.
The function of the partition wall to prevent the backflow of
When it is less than doubled, high temperature combustion gas from the combustion zone to the melting zone
This will lead to problems such as obstruction of the flow of the gas.
Therefore, when a partition wall is provided, change the flow path diameter of the partition wall in the combustion melting furnace.
It is recommended to use 0.6 to 0.9 times the diameter .

By forming the outer wall of the furnace wall of the melting zone of the combustion melting furnace into a water-cooled structure or an air-cooled structure, the melting loss of the furnace wall can be suppressed and the service life of the melting furnace can be extended. Further, although the present embodiment has a vertical shape, it goes without saying that it may have a horizontal shape.

[0021]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a sectional side view of a combustion melting apparatus according to an embodiment of the present invention. The combustion melting apparatus mainly has a melting furnace 1, and a slag portion 8 and a conveying means 19 (not shown) having the same structure as the conventional apparatus shown in FIG. 2 are connected to the lower part of the melting furnace 1. The waste melting and solidifying apparatus is formed as a whole.

The melting furnace 1 is provided with a throttle portion 7 (not shown) in the lower portion, and the inside of the furnace above the throttle portion 7 is composed of an upper combustion zone 22 and a lower melting zone 23. . The combustion zone 22 is formed in a region where the main burner 2 is provided on the top wall and the fuel F and the primary combustion air A ₁ are supplied from the main burner 2, mixed and burned. In this combustion zone 22,
It suffices if 50% or more of the fuel burns, and the length L of the combustion zone 22 required for that is 0.5 to 1.5 times the inner diameter D, so an appropriate value within this range should be selected depending on the type of fuel used. Just select it. In order to keep the combustion zone 22 at a high temperature, it is preferable that the furnace wall has a refractory structure.

A partition wall 24 is provided between the combustion zone 22 and a melting zone 23 whose inner peripheral wall is made of refractory. Also, the melting zone 23
A pipe 9 for injecting the secondary combustion air A ₂ is connected to the side wall of the upper part of the partition wall immediately below the partition wall 24. A waste supply device comprising a hopper 3, a table feeder 4 and a valve 5 is branched and connected in the middle of the pipe 9, and the waste quantitatively cut by the table feeder 4 is dropped into the pipe 9 through the valve 5. The secondary combustion air A ₂ flowing in the pipe 9 is mixed and blown into the melting zone 23 together with the air A ₂ . A solid-gas two-phase flow consisting of waste and air is heated by high-temperature combustion gas fed from a channel surrounded by the inner wall of the partition wall 24 while swirling on the furnace wall surface in the melting zone 23,
Waste is melted and turned into slag.

The partition wall 24 is provided so that the waste material supplied to the melting zone 23 does not flow back into the combustion zone 22,
The primary air A ₁ is a swirling flow, and the central portion of the combustion zone 22 outlet,
That is, in order to generate a reverse flow region in the flow path portion of the partition wall 24,
By providing the partition wall, it is possible to prevent the inflow of waste (melted material). The flow passage inner diameter d of the partition wall 24 is d / D = with respect to the inner diameter D of the furnace wall from the viewpoint of preventing inflow and increasing pressure loss.
It may be selected in the range of 0.6 to 0.9. However, it is not necessary to provide the partition wall 24 depending on the structure of the inner wall of the furnace.

On the other hand, a flame detector 25 is provided above the combustion zone 22.
Is provided and the combustion zone 22 is separated from the melting zone 23, there is almost no waste in the combustion zone 22 and flame detection is accurate. That is, it becomes possible to prevent the occurrence of combustion interruption due to the misfire signal of the flame detector.
Also, the temperature of the furnace top can be maintained at a high temperature, and it is possible to prevent the ash adhesion trouble of the waste on the burner tile.

Since the melting wall 23 of the furnace wall structure is likely to be severely melted with a normal refractory material, the outer wall has a structure of a water cooling jacket or an air cooling jacket 26, and the inside thereof is a refractory material 27, which is self-contained. It is preferably protected by a coating.

[0027]

The present invention has the structure as described above and operates, and the combustion zone and the melting zone are present separately in the combustion melting furnace, and the space for the waste is present in the combustion zone. The concentration is extremely low, and it is possible to cause only combustion between the fuel and combustion air , which makes it possible to reliably and efficiently generate hot combustion gas, and in one melting zone It is possible to melt and slag the waste that is the material to be melted and the high temperature combustion gas from the combustion zone .
As a result , the melting process can be carried out smoothly, and because of this, clogging of the semi-molten material to the furnace wall is less likely to occur and clogging can be prevented, and combustion delay does not occur. Even if it is large, the waste can be completely melted, the processing capacity can be enhanced, and stable combustion-melting processing can be realized. Furthermore, due to the low spatial concentration in the combustion zone, it is emitted from the flame. It is possible to prevent the generated light from being easily attenuated, and thus to prevent the occurrence of the combustion interruption due to the misfire signal of the flame detector.

[Brief description of drawings]

FIG. 1 is a sectional side view of a combustion melting apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional side view showing an example of a conventionally proposed ash melting and solidifying apparatus.

[Explanation of symbols] 1--melting furnace 2--main burner 3--hopper
4--Table feeder 5--Valve 9-Pipe 22-Combustion zone
23--Melting zone 24--Partition wall 25--Flame detector 26--Water cooling jacket 27--Refractory F--Fuel A ₁ --Primary combustion air A ₂ --Secondary combustion air

Claims (2)

[Claims] 1. A waste having a combustion zone for mixing a fuel supplied from a burner and combustion air to generate high temperature combustion gas at the upstream side thereof, and having a waste supply hole, and a waste supplied from the supply hole. A combustion melting furnace having a melting zone in the downstream portion for melting a substance by the high temperature combustion gas from the combustion zone,
A combustion combustion melting apparatus for combusting and melting waste by the combustion melting furnace , wherein the burner is a top wall of the combustion melting furnace.
The apparatus for combusting and melting waste according to claim 1, wherein the length of the combustion zone of the combustion melting furnace is 0.5 to 1.5 times the inner diameter of the combustion zone. 2. The combustion melting of waste according to claim 1, wherein an annular partition is provided between the combustion zone and the melting zone, and the partition has a flow passage having an inner diameter of 0.6 to 0.9 times the inner diameter of the combustion melting furnace. apparatus.