JPH0739909B2 - Dust cooling system for melting furnace - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust removing cooling apparatus for a melting furnace for cooling high temperature exhaust gas discharged from the melting furnace.

[0002]

2. Description of the Related Art FIG. 11 is a sectional view showing a conventional aluminum alloy melting furnace.

In the figure, when a return material, which is once made into an aluminum alloy product, and an aluminum alloy ingot 13 (hereinafter simply referred to as "ingot") are supplied into a preheating tower 12 of a melting furnace 11, the ingot 13 is preheated. After the heat is received in the tower 12, it is completely melted by the burner 15 in the melting chamber 14. The molten aluminum alloy melted in the melting chamber 14 is pumped out from the molten metal outlet 16. During melting, exhaust gas is generated from the surface of the molten metal and the burner 15, and is therefore discharged from the exhaust duct 17 to the outside. However, if the exhaust gas is directly discharged to the outside, the environment inside the factory will be deteriorated and the residents around the factory will be damaged. Therefore, a dust remover is attached to the melting furnace 11 to discharge the exhaust gas with a bag filter. It is filtered and dusted before being discharged.

When the molten aluminum alloy is melted in the atmosphere, zinc, magnesium, titanium and the like contained in the alloy promote the promotion of aluminum oxide film formation, and these oxides are dissolved during melting. It becomes a fine oxide and mixes in the molten metal. Since the specific gravity of the oxide is almost the same as the specific gravity of the molten aluminum alloy, when mixed in the molten metal, the hydrogen gas that floats in the molten metal and penetrates into the molten aluminum alloy is adsorbed by the fine oxide. When this molten metal is poured into the mold, it mixes into the product, and foreign matter is mixed in or pinholes are generated due to hydrogen gas. In addition, when molten metal containing a large amount of oxide adheres to the small protrusions in the mold (metal mold), the oxide overlaps and adheres to that portion each time it is repeatedly poured, eventually forming a hard oxide layer. When pulling out the product from the mold, it interferes with the product, and the product does not come off, distortion occurs even if it comes off, and sometimes it causes damage such as damage. Therefore, in order to clean the molten aluminum alloy, it is necessary to remove the oxides generated on the molten metal surface of the melting furnace 14 and at the same time remove the fine oxides floating in the molten metal. Therefore, twice to several times a day, a flux, which is a flux for antioxidation and degassing, is charged into a molten metal, stirred, and reacted to generate a fine gas, which is suspended in the molten metal. The oxide is adsorbed and floated to clean the molten metal, and the oxide on the surface of the molten metal is separated from the aluminum alloy. When the oxide is removed, it is mixed in the oxide and discharged at the same time. The amount of loss of the aluminum alloy, which is a different matter, is reduced.

Here, when the gas discharged from the melting furnace 11 is supplied to the melting furnace 11 while the ingot 13 is full, the material receives heat in the preheating tower 12 in the melting furnace 11 to exchange heat. Therefore, the temperature of the exhaust gas is relatively low and is about 200 to 300 ° C.

On the other hand, when the ingot 13 is completely melted and no material is replenished, there is no heat exchange with the ingot 13 having a low temperature, so that the inside of the melting chamber 14 is heated by the burner 15 and has a high temperature. The gas is exhausted as it is, and the exhaust gas has a high temperature of about 500 ° C.

Further, the gas discharged from the melting chamber 14 is heated to a high temperature by the reaction heat when a flux, which is a flux for performing the above-mentioned oxidation prevention and degassing treatment, is introduced into the molten metal. Furthermore, once a day or once a week, the dissolution chamber 14
When all the materials charged in the above are melted and transferred to the holding chamber and the inside of the melting furnace 11 is cleaned using the flux, the burner 15 is burned until all the materials are melted. Therefore, high-temperature exhaust gas is discharged from the furnace top.

From the viewpoint of thermal efficiency, the gas in the melting furnace 11 which has been heated to a high temperature by melting and manipulating the above-mentioned materials has a small opening 18 formed through a channel steel or the like at the connecting portion with the exhaust duct 17 so as to remove the surrounding air. Exhaust duct 17 while sucking
Although it is cooled to some extent in order to flow through the inside, it is in a considerably high temperature state when passing through the bag filter in the dust remover additionally provided.

If this exhaust gas flows into the bag filter of the dust remover at a high temperature, the bag filter may burn. Therefore, the bag filter is installed as far away as possible from the melting furnace 11 to cool the exhaust gas while flowing, or the temperature of the high-temperature exhaust gas flowing in front of the bag filter is measured, and when a dangerous temperature is reached, , A device is installed to lower the temperature by mixing in secondary air to prevent a fire.

[0010]

However, in order to prevent a fire from being caused by high temperature exhaust gas, a bag filter is installed as far away from the melting furnace 11 as possible and the exhaust gas is cooled while flowing. Since the distance of the duct from the melting furnace to the dust removal is long, the equipment cost is high and a large installation space is required.

Further, when the temperature is lowered by mixing secondary air, the apparatus becomes large in size because it is necessary to send out a large amount of secondary air in a short time, and like the above, the equipment cost becomes high and a large space is required. Requires.

Since a low-temperature low-speed gas burner for melting and holding an aluminum alloy has been developed for several years,
High-performance furnaces with low thermal oxidization and high thermal efficiency have become popular, and are used extensively not only in small and medium-sized factories but also in large factories to reduce defects in aluminum alloy castings and cast high-quality aluminum castings. The factory environment is improving. However, in a foundry where air is easily polluted, this alone cannot secure a sufficiently good environment, and there is an urgent need to further improve the environment. The high-temperature exhaust gas discharged from the melting furnace 11 has a great influence not only on the inside of the factory but also on the environment around the factory.

Therefore, an object of the present invention is to provide a dust removal cooling device for a melting furnace which can cool high temperature exhaust gas generated from the melting furnace at a low cost in a small space.

[0014]

A dust removal cooling apparatus for a melting furnace according to the present invention has a plurality of storage containers into which high-temperature exhaust gas discharged from the melting furnace can flow, and the inside of the storage container can be installed. The particulate porous carbon-based filter material that cools by exchanging heat with the high-temperature exhaust gas flowing through it is filled through a wire mesh.

Here, as the granular porous carbon-based filtering material, for example, a filtering agent obtained by mixing waste paper with clay to form granules and baking and carbonizing them in a kiln can be used.

[0016]

In the present invention, the high-temperature exhaust gas discharged from the melting furnace is heat-exchanged with the granular porous carbon-based filter material when flowing through the granular porous carbon-based filter material in the storage container. To be cooled. This is because the granular porous carbon-based filter material has a high thermal conductivity even though it is a nonmetal, and exhibits a unique property that the thermal conductivity is equal to or higher than that of a general metal. Also, since the heat resistant temperature is as high as about 700 ° C,
Even if hot exhaust gas flows through, it will not burn.
Furthermore, since it is porous and adsorbs impurities, it also has a dust removing and deodorizing effect.

When the storage container containing the granular porous carbon-based filter medium is divided into multiple stages, the granular porous carbon-based filter medium in the storage container near the inlet that first comes into contact with the high-temperature exhaust gas is particularly effective. Since the degree of deterioration becomes faster, it is not necessary to replace all the granular porous carbon-based filter media each time when replacing the granular porous carbon-based filter media that has deteriorated on a regular basis, and partial deterioration is likely to occur. It suffices to take out only the storage container and replace the granular porous carbon-based filter material inside. In addition, the granular porous carbonaceous filter material that has deteriorated can be easily selected and replaced by using multiple stages. As a result, the labor and time for exchanging the granular porous carbon-based filter material can be shortened, the exchanging operation becomes easy, and the cost can be reduced.

[0018]

Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 is a perspective view showing a dust removing cooling apparatus for a melting furnace according to a first embodiment of the present invention, FIG. 2 is a partially cutaway front view showing the dust removing cooling apparatus for a melting furnace shown in FIG. 1, and FIG. 4 is a cross-sectional view showing a storage container storing the granular porous carbon-based filter material of FIG.
FIG. 3 is a perspective view showing the storage container of FIG. 2.

In the figure, the dust cooler 1 of the present embodiment comprises a cooling chamber 2 and a dust collecting chamber 3, and the cooling chamber 2 and the dust collecting chamber 3 are partitioned by a partition plate 4 having an opening 4a at the bottom. ing. An inflow port 5 is provided above the cooling chamber 2,
In addition, box-shaped storage containers 6 are vertically arranged in multiple stages (four stages in the figure). Each storage container 6 has a handle 6a on the front.
Is attached so that it can be taken in and out in the front-rear direction, and the top and bottom surfaces are open, and the bottom surface is covered with a wire mesh 6b having a mesh that does not drop the granular porous carbon-based filter material P. ing.

Here, the granular porous carbon-based filter medium P is a filter medium in which waste paper is mixed with clay to form granules, which are carbonized in a kiln and baked. This granular porous carbon-based filter material P is developed and sold under the trade name "Excellite" manufactured by Nippon Filter Ceramics. In addition, this granular porous carbon
System filtration material P is Japanese Patent Application No. 3-183214 (June 1991)
26th application), the title of the invention "Paper sludge as raw material"
A patent has been filed for "Suru filtration material". Granular porous carbon
The system filter material P has a particle size of about 2 to 35 mm and is dissolved.
Sieve considering the exhaust volume and pumping speed corresponding to the furnace capacity
Separate and use the granular porous carbon-based filter material P with the optimum particle size
is doing. Then, the size of the mesh of the wire netting 6b of the storage container 6 is set in accordance therewith.

On the other hand, in the dust collecting chamber 3, a plurality of bottomed cylindrical bag filters 7 having a bottom surface opened inside are suspended at regular intervals in a vertically replaceable manner. Further, a catch box 8 which can be freely taken in and out for receiving dust falling from the bag filter 7 is provided at the bottom of the dust collecting chamber 3, and a blower 9 for sucking and discharging the exhaust gas from the melting furnace is provided at the upper part.
Is installed.

The shaker 11 is a means for knocking down dust particles existing between the granular porous carbon-based filter media P of the storage container 6, and is adapted to electrically vibrate the storage container 6. However, the vibration may be manually applied to the storage container 6 from the timing of applying the vibration.

Next, the cooling and dust removal of the exhaust gas by the dust removal cooling device of the melting furnace of the present embodiment having the above-mentioned structure will be described.

Now, when the high temperature gas is discharged from the melting furnace, the exhaust gas is sucked by the operation of the blower 9 and flows into the cooling chamber 2 through the inflow port 5 of the dust removing cooler 1. The exhaust gas that has flowed into the cooling chamber 2 flows through the storage containers 6 arranged in four upper and lower stages in order from the upper stage to the lower stage.

At this time, since the granular porous carbon-based filter material P stored in each storage container 6 has both good thermal conductivity and good heat dissipation, it is accumulated in the high temperature exhaust gas flowing through the storage container 6. The amount of heat thus generated is heat-exchanged with the particulate porous carbon-based filter material P, becomes a low temperature, and flows out into the dust collecting chamber 3. As a result, the risk of the bag filter 7 burning due to the heating of the exhaust gas is avoided.

Further, since the granular porous carbon-based filter medium P is porous and acts as a filter medium, impurities such as NOx and chlorine gas in the exhaust gas are removed while flowing through the granular porous carbon-based filter medium P. To be done. Further, impurities not removed by the granular porous carbon-based filter material P are removed while passing through the bag filter 7.

The dust-exhausted exhaust gas that has passed through the bag filter 7 is discharged through the exhaust port 10 into and out of the factory.

The temperature of the exhaust gas is not always constant due to changes in the supply state and the melting state of the material in the melting furnace, and the high-temperature and low-temperature exhaust gases are alternately discharged and the granular porous carbon-based filter material P is used. Pass through. Therefore, the particulate porous carbon-based filter medium P that has been heated to a high temperature is, conversely, cooled when the next low-temperature exhaust gas passes through. On the other hand, the low-temperature exhaust gas that has passed through this portion is heat-received by the granular porous carbon-based filter material P, and then flows into the storage container 6 in the lower stage thereof, where it is cooled and then discharged into the dust collection chamber 3. .
As a result, the cooling effect is greater when the layer of the granular porous carbon-based filter material P is thick and is divided into multiple layers to form a multi-layer.

While the granular porous carbon-based filter medium P receives heat and deteriorates during use, the granular porous carbon-based filter medium P on the inflow side of the high-temperature exhaust gas and the granular porous carbon on the outflow side of the high-temperature exhaust gas. Since the degree of heat storage greatly differs from that of the system filter material P, the degree of deterioration also differs, and the degree of deterioration naturally increases on the inflow side where the heat storage is large.

As described above, in the dust removal cooling apparatus for the melting furnace of the above-described embodiment, the storage containers 6 through which the high-temperature exhaust gas discharged from the melting furnace can flow are built in four stages, and the inside of each storage container 6 is incorporated. The granular porous carbon-based filter material P that cools by exchanging heat with the high-temperature exhaust gas flowing through it is filled through the metal net 6b.

Therefore, according to the above-mentioned embodiment, when the high temperature exhaust gas discharged from the melting furnace is passed through the granular porous carbon-based filter material in the storage container, Since it is cooled by exchanging heat, it is possible to avoid the risk of burning the bag filter 7 in the dust collection chamber 3 in a small space without installing a large-scale device for sending the secondary air. Also, when the high temperature exhaust gas discharged from the furnace is forcibly sucked and removed, the air around the furnace is
Since it becomes the next air and is sucked at the same time, the high temperature ambient temperature around the melting furnace is also lowered by about 4 to 5 ° C, which contributes to the improvement of the working environment. Further, since the heat resistant temperature is as high as about 700 ° C., even if a high temperature gas flows through, it does not burn. Furthermore, since the granular porous carbon-based filter material P is porous and adsorbs impurities, it also has a dust removing and deodorizing effect and can remove impurities in exhaust gas. Therefore, depending on the physical properties of impurities in the exhaust gas, the processing capacity of the granular porous carbon-based filter material P, and the like, the dust collection chamber 3 to which the bag filter 7 is attached is attached.
It is possible to eliminate the need for installation of
The entire device can be miniaturized.

Since the storage container for storing the granular porous carbon-based filter material is divided into multiple stages, when replacing the deteriorated granular porous carbon-based filter material P, the entire granular material is replaced each time. It is not necessary to replace the porous carbon-based filter material P, and only the storage container 6 near the inflow side, which is likely to be partially deteriorated, may be taken out to replace the granular porous carbon-based filter material P. Moreover, the granular porous carbon-based filter material P that has deteriorated can be easily selected and replaced by adopting multiple stages. As a result, the material loss is reduced, the replacement weight of the granular porous carbon-based filtration material P per time is reduced, the work is facilitated, the time and effort for replacement are shortened, and the cost of the filtration material can be reduced. . Then, the granular porous carbon-based filter material P
It is possible to use each particle size according to the classification.

By the way, the above embodiment is applied to the dust collector / cooler 1 in which the exhaust gas from the melting furnace flows through the inside of the cooling chamber 2 from the upper side to the lower side. The same can be applied to the dust removing cooler or the like that flows from the lower side to the upper side in the cooling chamber 2 shown in FIGS. 5 to 8.

FIG. 5 is a partially cutaway front view showing a dust removal cooling apparatus for a melting furnace of a second embodiment of the present invention, FIG. 6 is a partially cutaway side view of FIG. 5, and FIG. 7 is a granular porous carbon of FIG. FIG. 8 is a partially cutaway front view showing the storage container filled with the system filter material, and FIG. 8 is a partially cutaway perspective view showing the storage container shown in FIG. In the figure, the same reference numerals as those in FIGS. 1 to 4 are the same as or correspond to the components of the above-described embodiment.

In the case of the dust-removing cooler in which the exhaust gas flows from the lower side to the upper side in the cooling chamber 2, the granular porous carbon-based filter material P in the storage container 6 is moved upward by blowing up the exhaust gas from the lower side. Wire mesh 6b is also stretched over the upper opening so as not to scatter.

Since the particulate porous carbon-based filter material P also has a dust removing and deodorizing action in this dust removing cooler, a separate dust removing chamber 3 is not provided and the cooling chamber 2 also serves as that. For this reason,
The size is smaller than that of the dust cooler 1 that flows from the upper side to the lower side in the above embodiment.

Other than this, the same operation as the dust removing cooler 1 of the first embodiment can be expected, and the same effect can be expected.

Further, the second embodiment is applied to the dust eliminator 1 in which the exhaust gas from the melting furnace flows through the inside of the cooling chamber 2 from the lower side to the upper side. The present invention can be similarly applied to a dust-removal cooler or the like that flows through the inside of the cooling chamber 2 from the upper side to the lower side, as shown in the basic embodiment of the second embodiment.

FIG. 9 is a partially cutaway front view showing a dust removing cooling apparatus for a melting furnace of a third embodiment of the present invention, and FIG. 10 is a partially cutaway side view of FIG. In the figure, the same reference numerals as those in FIGS. 1 to 8 are the same as or correspond to the components of the above-described embodiments.

Particularly, in the embodiment of this type, the exhaust gas from the melting furnace is applied to the dust remove cooler 1 in which the exhaust gas flows from the upper part to the lower part of the cooling chamber 2, and at the bottom of the cooling chamber 2. A receiving box 8 is provided for receiving dust falling from the granular porous carbon-based filter material P and being freely removable. Also in the present embodiment, the dust removing chamber 3 is not separately provided, and the cooling chamber 2 also serves as that. Therefore, the size is smaller than that of the dust cooler 1 that flows from the upper side to the lower side in the above-described embodiment.

It should be noted that the dust removal cooling device for the melting furnace in the case of carrying out the present invention does not always assume that the cooling chamber 2 and the dust removal chamber 3 are simultaneously configured in different compartments.
What has the functions of the cooling chamber 2 and the dust removing chamber 3 may be used.

[0043]

As described above, in the dust removal cooling apparatus for a melting furnace of the present invention, a plurality of storage containers, through which high-temperature exhaust gas discharged from the melting furnace can flow, are built into the storage container. The particulate porous carbon-based filter material that cools by exchanging heat with the high-temperature exhaust gas flowing through it is filled through a wire mesh. Therefore, when the high-temperature exhaust gas discharged from the melting furnace is cooled by exchanging heat with the granular porous carbon-based filter medium when flowing through the granular porous carbon-based filter medium in the storage container, It is possible to prevent the bag filter from burning and the like in a small space without installing a large-scale device for delivering the next air, and to reduce the high temperature ambient temperature around the melting furnace to improve the working environment. Since the heat-resistant temperature is high, the granular porous carbon-based filter material will not burn even if a high-temperature gas flows through. Further, since the granular porous carbon-based filter medium is porous and adsorbs impurities, dust removal,
It also has a deodorizing effect and can remove impurities in the exhaust gas. For this reason, depending on the physical properties of impurities in the exhaust gas, the processing capacity of the granular porous carbon-based filter material, etc., it is not necessary to separately install a dust collecting chamber, and the overall size of the device can be reduced.
Then, if the storage container storing the granular porous carbon-based filter material is divided into multiple stages, when replacing the periodically deteriorated granular porous carbon-based filter material, the storage in the vicinity of the inflow side that is likely to partially deteriorate It suffices to take out only the container and replace the granular porous carbon-based filter material, and the deteriorated granular porous carbon-based filter material can be easily selected and replaced. As a result, the material loss can be reduced, and the replacement weight of the granular porous carbon-based filter material per time is reduced to facilitate the work, and the time and effort for the replacement can be shortened. It is possible to use according to the classification of particle size.

[Brief description of drawings]

FIG. 1 is a perspective view showing a dust removing cooling apparatus for a melting furnace according to a first embodiment of the present invention.

FIG. 2 is a partially cutaway front view showing the dust removal cooling device of the melting furnace of FIG.

FIG. 3 is a cross-sectional view showing a storage container that stores the granular porous carbon-based filter material of FIG.

FIG. 4 is a perspective view showing the storage container of FIG.

FIG. 5 is a partially cutaway front view showing a dust removing cooling apparatus for a melting furnace according to a second embodiment of the present invention.

FIG. 6 is a partially cutaway side view of FIG.

FIG. 7 is a partially cutaway front view showing a container filled with the granular porous carbon-based filter material of FIG.

FIG. 8 is a partially cutaway perspective view showing the storage container of FIG.

FIG. 9 is a partially cutaway front view showing a dust removal cooling apparatus for a melting furnace according to a third embodiment of the present invention.

10 is a partially cutaway side view of FIG.

FIG. 11 is a cross-sectional view showing a conventional aluminum alloy melting furnace.

[Explanation of symbols]

 6 Storage Container 6b Wire Mesh P Granular Porous Carbon Filter Material

Claims (1)

[Claims] 1. A storage container having a plurality of stages incorporated therein, through which high-temperature exhaust gas discharged from a melting furnace can flow through, and a high-temperature exhaust gas which is filled in the storage container through a net and flows through the storage container. A dust removal cooling device for a melting furnace, comprising: a granular porous carbon-based filter material that exchanges heat with exhaust gas to cool, filter the exhaust gas, and remove dust.