JP3305491B2 - Melting furnace apparatus for granular material and melting furnace combustion method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for melting a particulate material and a method for burning a melting furnace.

[0002]

2. Description of the Related Art Techniques for fusing ceramics such as glass and granulated slag having a certain particle size and scraps of metal and the like are roughly classified into three types. (1) Combustion-type melting furnace The material is melted sequentially from the surface of the material by the flame of the burner. A surface melting furnace with an inclined hearth used for melting ash, a reflection furnace for non-ferrous metals, and a tower-type melting furnace And tank kilns for glass. (2) Electric melting furnace Typical examples of the arc furnace for melting iron scrap include a plasma furnace and a microwave furnace used for melting ash. (3) Coke bed method The shape is similar to the tower type melting furnace, but the material and fuel coke are mixed and charged into the tower, and high-temperature hot air is blown from below to generate heat in the furnace and melt sequentially. It is the same method as the blast furnace.

[0003]

[Problems to be solved by the invention]

(1) Combustion-type melting furnace In melting a light alloy such as aluminum having a relatively low melting point, a normal flame temperature using combustion air at normal temperature is sufficient.
It often melts efficiently using a tower type melting furnace while preheating the material with exhaust gas. However, melting high melting point metals and ceramics, such as copper and iron, requires high flame temperatures, so the combustion air must be preheated and used regardless of the type of furnace used. . Air preheating is also an indispensable element from the viewpoint of effective use of exhaust heat. There are mainly two methods for obtaining preheated air: a recuperator method and an external regenerative method, but each has disadvantages. Recuperator method This uses the heat of exhaust gas to preheat combustion air in a heat exchanger.However, the equipment is outside the furnace body, loss is likely to occur during exhaust gas recovery, and the equipment is made of metal. High-temperature preheated air due to the fact that it must be used even when a high exhaust temperature can be obtained due to its low temperature and heat exchange efficiency itself due to the indirect heat transfer form through the metal surface Cannot be obtained. Generally around 400 ° C.
Flame temperature does not rise so much, resulting in an energy saving rate of 20
%. An ash surface melting furnace and a reverberatory furnace for melting metals correspond to this. External regenerative method In a furnace type with one pair (or multiple pairs) of heat storage,
Fuel is burned by air passing through one of the heat storage bodies, and the exhaust gas is guided to the opposite heat storage body to recover retained heat. By repeating this, high efficiency can be maintained. This is called heat storage combustion. Since the heat storage body is made of ceramic, the exhaust gas from the furnace body can be directly recovered at a high temperature, and since heat exchange is performed directly by the surface of the heat storage body, there is an advantage that a considerably high preheated air temperature can be obtained. These include tank furnaces for melting glass with a heat storage room beside the melting furnace, and furnaces using compact regenerative burners. This method has a problem in high-temperature durability and corrosion resistance of the heat storage element, and is not suitable for dissolving copper scrap and dissolving waste and ceramics having a large amount of corrosive components. In addition, there is no element to preheat the material, and it cannot be said to be a thorough waste heat recovery. Since a surface melting mainly composed of radiation heat transfer from the two systems both flame will cause excessive flame temperature is generally in NO _x becomes higher tendency. (2) Electric melting furnace This method has an advantage that a high temperature can be easily obtained, iron components can be dissolved, and a large amount of exhaust gas is not generated. However, equipment such as an electrode supply device and a power supply device requires a considerable cost, and the cost of a graphite electrode to be consumed is extremely high. Also, the power cost related to the operation is high, and the total cost related to the treatment is higher than that of the combustion type. Since the power consumption changes drastically with time, compatibility with a power supply system without a buffer element also becomes a problem, regardless of whether it is commercial or self-generated. (3) Coke bed method This method is an application of a blast furnace, but it is necessary to blow high-temperature hot air (1000 ° C or more) from the bottom in order to burn coke as a fuel, which requires a large-scale hot air generator. Become. This type also generates a large amount of unburned components such as CO and harmful substances, and is difficult to operate. In addition, problems remain in the future coke supply situation.

[0004]

In order to solve the above-mentioned problems, the present invention comprises a furnace body having two inclined hearths integrally formed in a U-shape on the furnace bottom side, and a material on the furnace top. A charging section is provided, a basin is provided at the bottom of the furnace, a fuel nozzle is provided at an upper portion of the basin toward each of the inclined hearths, and a tap hole is provided at the bottom of the furnace, and each of the materials is provided. The input section is provided with an apparatus connected to the supply / exhaust section.

Further, according to the present invention, a furnace body having two inclined hearths is integrally formed in a U-shape on the furnace bottom side, a material charging section is provided on the furnace top, and a basin is provided on the furnace bottom. A fuel nozzle is provided on a ceiling wall or a side wall of the furnace body, and a tap hole is provided on the furnace bottom, and each of the material input sections is connected to a supply / exhaust section. is there.

According to the present invention, a furnace body having two inclined hearths is integrally formed in a U-shape on the furnace bottom side, a material charging section is provided on a furnace top, and a basin is provided on the furnace bottom. A fuel nozzle is provided at the upper part of the furnace bottom between the two inclined hearths, and a tap hole is provided at the furnace bottom, and each of the material input sections is connected to a supply / exhaust section. To provide.

The present invention also provides an apparatus characterized in that the inclined hearth comprises a staircase-shaped main hearth and a slightly flattened upper hearth.

Further, the present invention provides an apparatus characterized in that a pusher for pushing out a material in the furnace direction is provided on the preliminary hearth.

Further, according to the present invention, the two material input sections are connected via one hopper, and the two supply / exhaust sections are
An apparatus is provided which is connected to one air inlet and one exhaust port via a valve. .

Further, the present invention provides an apparatus wherein the fuel nozzle is a burner / nozzle provided with an air nozzle.

Further, according to the present invention, a furnace body having two inclined hearths is integrally formed in a U-shape on the furnace bottom side, a material charging section is provided on the furnace top, and a basin is provided on the furnace bottom. A burner nozzle is provided at the upper part of the pool chamber toward each inclined hearth, and a tap hole is provided at the furnace bottom, and each of the material charging parts is connected to a supply / exhaust part. Sometimes, fuel and air are ejected from the burner / shared nozzle, and after the hearth reaches a high-temperature region, fuel is ejected from one burner / shared nozzle only into one furnace and into another furnace. The combustion air is introduced from the upper supply / exhaust section, and is guided to the inside of the furnace in which the fuel is introduced to perform mixed combustion.
While preheating the material in the material packed tower, the material is discharged through a supply / exhaust section provided on the upper part thereof, and the supply, exhaust and fuel ejection are alternately performed on the two inclined hearths at regular intervals. The present invention provides a melting furnace combustion method characterized by being switched and executed.

Further, according to the present invention, a furnace body having two inclined hearths is integrally formed in a U-shape on a furnace bottom side, a material charging section is provided on a furnace top, and a basin is provided on the furnace bottom. A burner nozzle is provided on a ceiling wall or a side wall of the furnace body, a tap hole is provided on the furnace bottom, and each of the material charging sections is connected to a supply / exhaust section. After fuel and air are introduced from, the hearth reaches a high temperature area,
Fuel is injected into one furnace only from the one nozzle serving as a burner, and air is injected from the top of the furnace into the same furnace to mix and burn in the furnace. Is discharged through an air supply / exhaust section above the preheating furnace, and the combustion is performed by alternately switching the two inclined hearths at regular time intervals. Is what you do.

Further, according to the present invention, a furnace body having two inclined hearths is integrally formed in a U-shape on the furnace bottom side, a material charging section is provided on a furnace top, and a basin is provided on the furnace bottom. A burner nozzle is provided in the upper part of the furnace bottom between the two inclined hearths, and a tap hole is provided in the furnace bottom, and each of the material charging sections is connected to a supply / exhaust section. After fuel and air are introduced from the burner / shared nozzle, after the hearth reaches the high temperature region, fuel is injected into the furnace only from the burner / shared nozzle and air is injected from the furnace top into one furnace. Mixed combustion in another furnace, and the exhaust gas is discharged through a supply / exhaust unit located above the preheated material in the furnace while preheating the material in the furnace.
The present invention provides a melting furnace combustion method characterized in that combustion is performed by alternately switching two inclined hearths at regular time intervals.

[0014]

According to the present invention, two inclined hearths are alternately switched to burn, and preheating, combustion, and exhaust are effectively performed.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference numeral 1 denotes a furnace body having an inclined hearth 2;
The furnace body 1 is integrally formed in a U-shape on the furnace bottom side, a material charging section 4 is provided on the furnace top 3, a basin chamber 6 is provided on the furnace bottom 5, and an upper part of the basin chamber 6 is provided. Is provided with a fuel nozzle 7 directed toward each inclined hearth 2. A tap hole 8 is provided in the furnace bottom 5, and the material input sections 4 provided in the furnace top 3 are connected to a supply / exhaust section 9. The fuel nozzle 7 may be attached to a ceiling wall or a side wall of the material packed tower 1 as shown in FIGS. 3 and 4, or a hearth between two inclined hearths 2 as shown in FIG. One may be installed at the top of 5 and shared. The inclined hearth 2 is composed of a main hearth 10 having a step shape and a preliminary flat hearth 11 provided on the upper part thereof.
The angle of inclination of the inclined hearth 2 is preferably an angle of repose according to the fluidity of the material. The preliminary hearth 11 is provided with a pusher 18 for extruding the material 17 in the inclined hearth 2 direction. The two material input sections 4 are connected via one hopper 12 and the two supply / exhaust sections 9 are connected to one exhaust port 1.
3 and the air inlet 14 are connected via switching valves V ₁ , V ₂ , V ₃ , V ₄ . Further, the fuel nozzle 7
Burner dual-purpose nozzle 1 having air nozzle 15 indicated by broken line
6 is acceptable. Further, according to the present invention, in the above-described configuration,
In the case of FIGS. 1 and 2, at the start, combustion is performed using the burner / nozzle 16, and when the furnace bottom 5 becomes high temperature, for example, 750 ° C. or more, fuel is supplied only to the furnace B side. Then, the preheated air introduced from the furnace top 3 on the other furnace A side is mixed and burned on the furnace B side, and the exhaust gas is exhausted through the supply / exhaust unit 9 while preheating the material on the furnace B side. I do. Such combustion is performed by alternately switching the introduction of air and fuel. Further, in the case of FIGS.
Alternatively, a burner / nozzle 16 is provided on the ceiling or side wall of the furnace body 1 so that fuel is introduced into the furnace A on the furnace A side, and combustion air is supplied and exhausted from the furnace top 3 of the furnace A at the same time. The gas is introduced into the furnace A from the section 9, mixed and burned in the furnace A, the combustion gas is guided to the other furnace B side, and the material 17 in the furnace B is discharged through the supply / exhaust section 9 while preheating. Such combustion is performed by alternately switching the two material packed towers 1 to perform combustion. Further, in the case of FIG. 5, one fuel nozzle 7 or a burner nozzle 16 is provided above the hearth 5 between the two inclined hearths 2.
Is installed, and combustion can be performed corresponding to the combustion air alternately introduced into the inclined hearth 2.

First, in FIGS. 1 and 2, a material 17 is uniformly charged from the material charging section 4 into each of the material packed towers 1.
At the time of start, for example, the burner / nozzle 16 is used. That is, combustion air is introduced from the air nozzle 15 and fuel is introduced into the furnace A from the fuel nozzle 7. At this time, no air was introduced from the other
Alternatively, only gas is exhausted from one furnace top 3. When the combustion starts in the burner nozzle 16 and the hearth 2 is in a high temperature state, for example, 750 ° C. or more, the air nozzle 1
5, the fuel is introduced into the furnace B only from the burner nozzle 16, and the combustion air flows from the furnace top 3, that is, through the air inlet 14 and the supply / exhaust unit 9. After that, it is introduced into the furnace A. That is, when air is introduced into the furnace A in the figure, the switching valves V ₁ and V ₄ are opened and the switching valves V ₂ and V ₄ are opened in order to achieve the flow of air supply and exhaust indicated by the arrows in the figure. _Three
Is closed, and combustion air is introduced. The combustion air reaches the bottom portion 2 while being preheated while descending, and is further introduced into the furnace A and burns on the B side while being mixed with the fuel gas introduced from the burner nozzle 16. Exhaust heats the material 17 through the furnace B and is exhausted from the exhaust port 13. Before the gas is exhausted, the material 17 in the furnace B is heated while raising the packed layer of the material 17. Thus, the material 17 is exposed to a high temperature and melts to become a molten metal. The molten metal is discharged from the tap 8 as appropriate. At this time, the inclined hearth 2 has a large heat exchange area due to the main hearth 10 configured in a step shape,
The material 17 can be effectively heated. Further, the material 17 can be filled in the furnace by the preheating hearth 11 which is slightly flat, and effective preheating can be performed. The material 17 can be appropriately pushed into the furnace by the pusher 18. After a fixed time, contrary to the above, the switching valves V ₁ , V ₂ , V ₃ and V ₄ are switched to inject fuel into the furnace A and introduce air into the furnace B to perform combustion. For example, the combustion is switched at intervals of several tens of seconds to several tens of minutes. In the case of FIGS. 3 and 4, since the inside of the furnace A from which the fuel is ejected, for example, the inside of the furnace A from which the air is ejected is the same, the combustion is performed in the same inside of the furnace A, and the exhaust is performed by another furnace. While preheating the material 17 in the furnace B, the material 17 is discharged through the supply / exhaust portion 9 of the furnace top 3. Further, in the case of FIG. 5, the burner-cum-nozzle 16 is provided one above the hearth 5 between the two inclined hearths 2 so as to be shared by the two inclined hearths 2. For this reason, the fuel is always introduced into the furnace, and only the combustion air is alternately introduced into the furnaces A and B to be alternately burned. Others are the same as described above. At this time, the material is suitably a ceramic or granulated slag having a certain particle size, a metal scrap, or a pellet made of powder or an organic binder or the like so that air or exhaust gas can pass therethrough. . Also, as described above, when the hot water is discharged from the tap 8, the filling of the material is reduced, so that the material 17 is successively supplied from the material charging section 7 via the hopper 12 so that the height of the material 17 becomes uniform. It is thrown.

[0017]

As described above, the present invention has the following advantages. (1) Since the material to be treated itself serves as a heat storage,
It is easy to use high temperature (150
0 ° C.). Also, since the heat storage material is a material, there is no need to worry about corrosion of the heat storage material (self-regenerative method). For this reason, the most efficient operation without maintenance is possible. Of course, an external heat exchanger (for a recuperator system) and a hot air generator (for a coke bed system) are not required. (2) Every time the material is melted from the lower part, the sensible heat of the exhaust gas is efficiently recovered while adjusting the height of the material by supplying the material at room temperature from the upper part as needed. 10
The exhaust temperature can be reduced to about 0 ° C (material preheating). (3) Volatile impurities are carried along with the exhaust gas, but the temperature of the exhaust gas decreases in the course of heat exchange with the material, so that the impurities are intensively deposited at a certain position in the packed tower. Since the solidification temperature is determined by the component, the deposition position is determined if the required component is known.The deposition amount is concentrated and increases with the elapse of the operation time, so the maintenance position is determined in advance at this position. By setting up a zone and periodically cleaning the material-filled layer or replacing a part of the material (heat storage material), harmful substances such as heavy metals that pollute the atmosphere can be recovered in advance for each component. The load on the exhaust gas treatment equipment on the downstream side is reduced (filtering effect), and an organic binder or the like for converting the powder into a bellet shape based on the same principle is used after a certain period of use.
If it is collected periodically because it is concentrated in the upper low-temperature portion, it can be repeatedly used as a raw material for forming pellets from powder (binder-recycling effect).
(4) Since the material is completely melted in the molten pool, the quality of the molten metal to be poured becomes uniform. (5) In the connection portion, fuel is injected into the flow of high-temperature air. However, in this method, mixing takes place over a certain period of time, so that an excessive rise in flame temperature is avoided, and as a result NO
The occurrence of _x is also suppressed. (6) Normally, heating on the B side is performed using the same A side burner as when mixing the fuel supplied from the B side burner (or fuel nozzle) with the high temperature air supplied from the A side. Although if the two ways to use a mixture of fuel supplied, wherein the fuel two-stage effect is obtained by supplying a portion of the fuel from both sides of the burner (the), can be further reduced of the NO _x Becomes (7) The spare hearth and the material input section
Since the exhaust gas temperature drops sharply and the radiation in the furnace is also blocked by the material, the furnace body is kept well.

[Brief description of the drawings]

FIG. 1 is an explanatory plan sectional view of the present invention.

FIG. 2 is a vertical explanatory view of FIG.

FIG. 3 is an explanatory plan sectional view of another embodiment of the present invention.

FIG. 4 is a vertical explanatory view of FIG. 3;

FIG. 5 is an explanatory plan sectional view of another embodiment of the present invention.

FIG. 6 is a vertical explanatory view of FIG. 5;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Furnace body 2 Inclined hearth 3 Furnace top 4 Material input part 5 Furnace bottom 6 Pool chamber 7 Fuel nozzle 8 Outlet 9 Supply / exhaust part 10 Main hearth 11 Preliminary hearth 12 Hopper 13 Exhaust port 14 Air inlet 15 Air nozzles 16 bar - Na combined nozzle 17 material 18 pusher - 19 Mentezo - down _{V 1, V 2, V 3} , V 4 switching valve

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI F27D 13/00 F27D 13/00 F

Claims (10)

(57) [Claims] 1. A furnace body having two inclined hearths is integrally formed in a U-shape on a furnace bottom side, a material charging section is provided on a furnace top, and a basin chamber is provided on the furnace bottom. A granular material, wherein a fuel nozzle is provided at an upper portion of the pool chamber toward each of the inclined hearths, a tap hole is provided at the furnace bottom, and each of the material charging sections is connected to a supply / exhaust section. Melting furnace equipment. 2. A furnace body having two inclined hearths is integrally formed in a U-shape on the furnace bottom side, a material charging section is provided on a furnace top, and a basin chamber is provided on the furnace bottom. A granular material melting furnace apparatus, wherein a fuel nozzle is provided on a ceiling wall or a side wall of a furnace body, a tap hole is provided on the furnace bottom, and each of the material input sections is connected to a supply / exhaust section. 3. A furnace body having two inclined hearths is integrally formed in a U-shape on the furnace bottom side, a material charging section is provided on a furnace top, and a basin chamber is provided on the furnace bottom. A furnace for melting particulate matter, characterized in that a fuel nozzle is provided at the upper part of the furnace bottom between two inclined hearths, a tap hole is provided at the furnace bottom, and each of the material charging parts is connected to a supply / exhaust part. . 4. The furnace for melting particulate matter according to claim 1, wherein the inclined hearth comprises a stepped main hearth and a slightly flattened preliminary hearth. 5. The pre-furnace hearth is provided with a pusher for extruding the material in the furnace direction.
4. The melting furnace device for particulate matter according to claim 3. 6. The two material charging sections are connected via one hopper, and the two supply / exhaust sections are connected via an air inlet and an exhaust port via a valve. 4. The apparatus for melting particulate matter according to claim 1, wherein: 7. The apparatus according to claim 1, wherein the fuel nozzle is a burner nozzle having an air nozzle. 8. A furnace body having two inclined hearths is integrally formed in a U-shape on the furnace bottom side, a material charging section is provided on a furnace top, and a water pool is provided on a furnace bottom. A burner nozzle is provided at the upper part of the basin toward each inclined hearth, and a tap hole is provided at the bottom of the furnace, and each material charging part is connected to a supply / exhaust part. After the fuel and air are ejected from the combined nozzle and the hearth reaches the high temperature region, the fuel is ejected from the one burner combined nozzle only into one furnace and the other furnace has the upper part thereof. Combustion air is introduced from a supply / exhaust section, guided to the inside of the furnace where the fuel is introduced, and mixed and combusted. Exhaust gas is discharged through the exhaust part, and the supply, exhaust and fuel injection are performed on two inclined hearths A method for burning a particulate matter in a melting furnace, wherein the method is carried out by alternately switching every time. 9. A furnace body having two inclined hearths is integrally formed in a U-shape on a furnace bottom side, a material charging section is provided on a furnace top, and a basin chamber is provided on a furnace bottom. A burner nozzle is provided on the ceiling wall or side wall of the furnace body, a tap hole is provided on the furnace bottom, and each of the material charging sections is connected to a supply / exhaust section. At the start, fuel and air are supplied from the burner nozzle. After the hearth reaches the high-temperature area, fuel is injected into one furnace only from the one burner / serving nozzle, and air is injected from the furnace top in the same furnace, Mixing and burning in the furnace, the exhaust preheats the material in the other furnace, but discharges it through the supply / exhaust section above it, and the combustion alternates the two inclined hearths at regular intervals. A method for burning a particulate matter in a melting furnace, wherein the method is performed by switching. 10. A furnace body having two inclined hearths is integrally formed in a U-shape on a furnace bottom side, a material charging section is provided on a furnace top, and a basin chamber is provided on a furnace bottom. A burner nozzle is provided at the upper part of the furnace bottom between the two inclined hearths, and a tap hole is provided at the furnace bottom, and each of the material charging sections is connected to a supply / exhaust section. After fuel and air are introduced from the furnace floor and the hearth reaches the high-temperature region, fuel is injected into the furnace only from the burner nozzle, and air is injected from the furnace top into one furnace, and the other Mixing and burning in the furnace, the exhaust preheats the material in the furnace, but discharges it through the supply / exhaust section above it, and the combustion alternates between the two inclined hearths at regular intervals. A method for burning a particulate matter in a melting furnace.