JP2002226866A - Method for dryning fine particle matter and method for blasting the matter into furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for drying a fine particle matter, especially coke and a method for blasting the matter into a furnace, requiring no specific drying facility for drying and no specific transfer means such as a tank truck and the like and no large area for receiving and capable of reducing the cost. SOLUTION: This method for drying a fine particle matter is to receive the fine particle matter easily transferred and having a predetermined particle size and 10-14% water content in at least one storage hopper and dry the fine particle matter to have the predetermined water content in a state to be air transferred to the furnace through a pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for drying fine powder such as coke, and more particularly to a method for drying coke having a high moisture content to a moisture content capable of being transported pneumatically in a storage hopper.

[0002]

2. Description of the Related Art Fine powders such as coke, coal, metal and the like are dried to a predetermined moisture content in a predetermined dryer depending on their use. Coke which is one of the fine powders will be described below. Coke is used not only as a heat source but also as a reducing agent in steelmaking melting furnaces using iron scrap as a raw material, and is indispensable in slag forming for improving thermal efficiency. At present, coke used in many factories is powdered coke having a water content of 2% or less, aggregate coke having a particle size of 10 mm or more, and water content of 1 mm or less having a particle size of about 5 mm or less.
There is 0-14% wet coke.

[0003] Coke powder having a water content of 2% or less is introduced into a melting furnace by pneumatic transportation. Agglomerated coke is difficult to pneumatically transport due to its large particle size. The coke is charged into the furnace with a bucket of iron scrap (melted raw material) or dropped naturally through a chute provided on the furnace. It is thrown in. A water-containing coke having a particle size of about 5 mm or less and a water content of 10 to 14% is also difficult to be transported by air, and is therefore introduced into the furnace in the same manner as the aggregate coke.

[0004] However, in the above-described method of loading into the furnace by natural fall through the chute, carbon in the molten steel may be uneven, or the dust may be drawn by the dust collector at the time of loading, leading to deterioration of the yield. In some cases, inconvenience may occur in operation.

Therefore, in order to solve the above-mentioned problem,
Conventionally, a water-containing coke having a particle diameter of about 5 mm or less and a water content of 10 to 14% has been conventionally dried in a predetermined drying apparatus to prepare powdered coke having a water content of 2% or less. The drying device is, for example, a vertical ventilation (moving bed) dryer. In a vented vertical (moving bed) dryer, the wet coke is
Because of its own weight, it moves down as a moving bed, and during this time, hot air is passed through the bed to perform drying. Therefore, it is suitable as a large-volume continuous dryer for water-containing coke having relatively low water content. In this dryer, the method of blowing hot air is adjusted so as to reduce uneven drying. Depending on the method of blowing hot air, it is classified into two types: a looper blowing type and a side wall blowing type.

In the looper blowing type, a large number of triangles formed of coke are vertically arranged in a zigzag pattern, and hot air is fed into the triangle formed of coke. Since the opposite surface to which the hot air is introduced is cut off, the hot air enters the coke layer from the bottom of the triangle mountain and vents through the coke layer. This reduces uneven coke drying.

[0007] In the side wall blow-in type, hot air is sent from one side to a coke layer that slowly descends from above, and is exhausted from the side opposite to the side into which the hot air is sent. This is so-called through-air drying. However, according to this method, since the whole is a flat layer, there is no mixing of coke particles and drying unevenness is caused. Therefore, a zigzag passage is provided so that the coke particles can be mixed and inverted well.

The above two methods have the following features. Since operations are performed continuously, it is suitable for mass processing. Furthermore, the structure is simple and the handling is easy. That is,
Hydrous coke is continuously charged from the upper part of the apparatus and continuously discharged from the lower part of the apparatus. By discharging the water-containing coke layer from the lower part by a constant amount, the water-containing coke layer is dried by hot air while descending sequentially, so that stable operation can be performed without any need for manual operation. Furthermore,
Requires less power. That is, the ventilation resistance of the water-containing coke layer is about 10 to 100 mm water column, the blowing power is small, and there is almost no driving part, so the required power is extremely small. Further, the heat transfer capacity coefficient is large, the heat transfer amount per unit volume is large, and the units can be stacked in the height direction, so that the installation space is small. Furthermore,
The residence time can be freely adjusted. That is, since the residence time is determined only by the discharge speed, the adjustment can be freely performed. Therefore, it is suitable for drying which takes a relatively long time.

Further, there is a stirring type dryer as another dryer. Stirring dryers are classified into a hot air type and a conduction type according to a coke heat receiving method and a stirring method, and the conduction type is further classified into a low speed stirring type and a high speed stirring type.
The characteristics of this dryer are as follows. That is, since the water-containing coke and the hot air are in good contact with each other by the high-speed stirring blade (outer peripheral speed of 5 to 15 m / sec), the critical water content is low and the water content is 2 to 3%.
About. Since the evaporation of water in the first half of the dryer is active and the temperature of the hot air in the oven drops rapidly, the temperature of the coke does not rise so much even if high-temperature hot air is used.
The drying time is generally as short as 2 to 10 minutes, and the amount of coke held in the vessel is small.

Although the above-mentioned methods all have the above-mentioned excellent characteristics, a special dryer for drying coke is required, and the cost for installation and operation of facilities is reduced. Has limitations.

Further, any of the above-mentioned methods can be used to dry a water-containing coke having a particle size of about 5 mm or less and a water content of 10 to 14% to prepare a powdered coke having a water content of 2% or less. The dried coke breeze is easily scattered, and a tank lorry is used to transport the coke to a storage hopper.

FIG. 3 shows a conventional method of receiving and blowing coke breeze. As shown in FIG. 3, the coke breeze having a moisture content of 2% or less prepared by a predetermined dryer is moved to a location where the storage hopper 21 is located by the tank lorry 22. An incoming air supply line 24 is set between the tank lorry 22 and the storage hopper 21. Therefore, the tank lorry 22 moved to a predetermined place and the receiving air supply line 24 provided in the storage hopper 21 are connected, and the coke breeze is
It is stored in the storage hopper 21 from the tank lorry 22 through the receiving air supply line 24.

A coke blowing device 23 is provided below the storage hopper 21, and a blowing air supply line 26 is provided between the blowing device 23 and the furnace 25. The coke breeze powder 30 stored in the storage hopper 21 is blown into the furnace 25 at a predetermined speed and amount through a blowing air supply line 26 by a blowing device 23 provided below the storage hopper. .

[0014]

As described above, in the conventional method of drying coke using a separate dryer, a special dryer is required, and it is necessary to reduce costs such as facility installation and operation costs. There is a limit. Furthermore, the coke breeze dried as described above is easily scattered and contains many pharmaceuticals for transportation, and requires tank lorries and the like. When a tank lorry is used, there is a problem that it takes time to receive the tank lorry from the tank lorry to the storage hopper. Further, in order to receive a large amount of coke breeze, a large number of tank lorries and a wide receiving place are required, and there is a problem that it is difficult to secure this wide place in a factory in an urban area.

Accordingly, an object of the present invention is to eliminate the need for a special drying facility for drying and a special transportation means such as a tank lorry, to require a large space for receiving, to reduce the cost, and to reduce the cost of fine powders. It is an object of the present invention to provide a method for drying coke and a method for blowing into a furnace.

[0016]

Means for Solving the Problems The present inventor has made intensive studies to solve the above-mentioned problems of the prior art. As a result, low-cost, high-moisture content coke is received in a storage facility such as a storage hopper in a high-moisture-content state, and the storage facility itself dries the water-containing coke to prepare powdered coke. It has been found that large quantities can be transported in a short time at low cost by a dump truck, a belt conveyor, and the like, and that the prepared coke breeze can be blown into the furnace. Furthermore, it has been found that coke breeze can be more effectively prepared by sending high-temperature air to a storage facility such as a storage hopper using a waste heat source not used around the melting furnace.

The present invention has been made on the basis of the above-described findings. The first aspect of the method for drying fine powder according to the present invention is directed to a method for easily transporting fine powder having a predetermined particle size of 10% or more. Receiving the fines having a moisture content in at least one storage hopper, and drying the fines in the storage hopper to a predetermined moisture content in a state capable of being pneumatically transported through a pipe into a furnace. It is a drying method.

In a second aspect of the method for drying fine powder according to the present invention, a fine powder having a predetermined particle size and having a water content of 10 to 14%, which is easy to transport, is received in at least one storage hopper. A method for drying fine powder, characterized by drying in a storage hopper to a predetermined moisture content in a state capable of being pneumatically transported into a furnace through a pipe.

In a third aspect of the method for drying fine powder according to the present invention, the storage hopper comprises a plurality of storage hoppers, and the plurality of storage hoppers are combined to continuously inject into the furnace. A method of drying a fine powder, comprising drying the fine powder as much as possible.

A fourth aspect of the method for drying a fine powder according to the present invention is a method for drying a fine powder, wherein the drying of the fine powder is performed by compressed air.

A fifth aspect of the method for drying a fine powder according to the present invention is a method for drying a fine powder, wherein the drying of the fine powder is performed by using recovered waste heat.

A sixth aspect of the method for drying fine powder according to the present invention is characterized in that the predetermined particle size is about 5 mm or less and the predetermined moisture content is less than 10%. It is a drying method.

In a seventh aspect of the method for drying fine powder according to the present invention, the fine powder having a water content of about 10 to 14% is conveyed to the storage hopper by a conveyor. It is a drying method.

An eighth aspect of the method for drying a fine powder according to the present invention is a method for drying a fine powder, wherein the fine powder is coke.

A ninth aspect of the method for drying fine powder according to the present invention is a method for drying fine powder, wherein the fine powder is coal.

A tenth aspect of the method for drying a fine powder according to the present invention is a method for drying a fine powder, wherein the fine powder is a metal.

The first aspect of the method for injecting a fine powder into a furnace according to the present invention is as follows.
The high-moisture content fine powder is received in at least one storage hopper, and is dried in the storage hopper to a predetermined moisture content in a state where it can be pneumatically transported through a pipe into a furnace. This is a method of blowing fine powder into a furnace by blowing the fine powder into a furnace by a pneumatic facility installed below the storage hopper.

The second aspect of the method for injecting a fine powder into a furnace according to the present invention is that the powder having a predetermined particle size is easily transported.
The fines having a moisture content of 14% are received in at least one storage hopper and dried in said storage hopper to a predetermined moisture content which is pneumatically transportable through pipes and into a furnace, and thus dried. This is a method of blowing fine powder into a furnace by blowing the fine powder into a furnace by a pneumatic facility installed below the storage hopper.

According to a third aspect of the method of blowing fines into a furnace according to the present invention, the storage hopper comprises a plurality of storage hoppers, and the plurality of storage hoppers are combined to continuously form the furnace. And drying the fine powder so that the fine powder can be injected into the furnace.

[0030] A fourth aspect of the method of blowing fines into a furnace according to the present invention is that the predetermined particle size is about 5 mm or less, the predetermined moisture content is less than 10%, and A method for blowing fine powder into a furnace, characterized in that drying of the powder is performed by air and / or hot air heated by recovered waste heat.

A fifth aspect of the method for blowing fines into a furnace according to the present invention is a method for blowing fines into a furnace, wherein the fines are coke.

A sixth aspect of the method for injecting fines into a furnace according to the present invention is a method for injecting fines into a furnace, wherein the fines are coal.

A seventh aspect of the method for injecting a fine powder into a furnace according to the present invention is a method for blowing a fine powder into a furnace, wherein the fine powder is a metal.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the method for drying fine powder and the method for blowing it into a furnace according to the present invention will be described in detail with reference to the drawings. In the method of drying fine powder according to the present invention, fine powder having a predetermined particle size and having a water content of about 10 to 14%, which is easy to transport, is received in at least one storage hopper, and piping is provided in the storage hopper. Through the furnace to a predetermined moisture content ready for air transport. Further, in the method for drying fine powder according to the present invention, the storage hopper is composed of a plurality of pieces, and the plurality of storage hoppers are combined so that the fine powder can be continuously injected into the furnace. dry.

Further, in the method for drying fine powder according to the present invention, the fine powder is dried by air including compressed air. Further, the drying of the fine powder may be performed by high-temperature air heated by the recovered waste heat. Further, it is preferable that the above-mentioned predetermined particle size is about 5 mm or less and the predetermined water content is less than 10%. The water content is more preferably 8% or less. Further, in the method for drying fine powder of the present invention, the fine powder having a water content of about 10 to 14% is conveyed to a storage hopper by a conveyor. The fine powder described above is coke, coal, or metal.

Further, in the method of blowing fine powder into a furnace according to the present invention, the powder having a predetermined particle size, which is easy to transport, has a diameter of about 1 mm.
The fines having a moisture content of 0 to 14% are received in at least one storage hopper and dried in said storage hopper to a predetermined moisture content which is pneumatically transportable through a pipe and into a furnace. The dried fine powder is blown into a furnace by a pneumatic facility installed below the storage hopper.

FIG. 1 is a diagram showing one embodiment of the method of drying coke and the method of blowing it into a furnace according to the present invention. As shown in FIG. 1, in the method for drying coke and the method for blowing it into a furnace according to the present invention, coke having a particle size of about 5 mm or less and a water content of about 10 to 14% is dumped into a dump truck 4.
Is transported to a place where the storage hopper / drying device 1 is located. In the vicinity of the storage hopper / drying device 1, there is provided a receiving hopper 7 for containing wet coke transported by a dump truck. A receiving conveyor 8 is provided extending from below the receiving hopper 7 to above the storage hopper / drying device 1.

A coke blowing device 3 is provided below the storage hopper / drying device 1.
Is provided with a blowing air supply line 5. An exhaust gas duct 9 is attached above the furnace 6. A hot air recovery machine 10 that recovers heat of the exhaust gas is installed in the exhaust gas duct 9. Further, a line for sending the drying gas 12 is provided at a required position near the furnace, and a flow control valve 11 for adjusting the flow rate of the drying gas is provided. The above-mentioned hot air recovery machine may be set on the drying gas line 14 for sending the drying gas. At a predetermined position of the drying gas line 14, a temperature control valve 13 for further controlling the temperature of the gas is provided.

The drying gas line 14 sends a drying gas having a temperature controlled by a temperature recovery device, a flow control valve, a temperature control valve, and the like, into the storage hopper / drying device 1. As shown in FIG. 1, the coke transported by the dump truck 4 to the location of the storage hopper / drying apparatus 1 and having a water content of about 10 to 14% and having a particle size of about 5 mm or less is firstly obtained.
It is stored in the receiving hopper. The water-containing coke stored in the receiving hopper is stored in the storage hopper /
It is moved by a receiving conveyor 8 extending upward from the drying device 1 and is loaded into the storage hopper / drying device 1 from above. In the storage hopper / drying apparatus 1, the water-containing coke is stacked, mixed if necessary, and moves slowly downward. In the storage hopper / drying device 1,
The compressed air is sent to dry the wet coke.

Further, when utilizing waste heat, the heat of the exhaust gas duct is recovered by a hot air recovery machine 10 for recovering heat from the exhaust gas duct 9 mounted above the furnace 6, and the heat is recovered at a required position near the furnace. The temperature of the provided line for sending the drying gas is increased. The drying gas passing through the drying gas line is controlled to a predetermined temperature by a flow control valve 11 for controlling the flow rate of the gas and a temperature control valve 13 for controlling the temperature of the gas. Sent.

The coke dried in this manner to a moisture content of 8% or less passes through the blowing air supply line 5 and the furnace 6 by the coke blowing device 3 provided below the storage hopper / drying device 1. It is blown in. A transport test was performed under the following conditions by the method described above. That is, the transfer weight: 200 kg, the transfer speed: 60 kg / min, the transfer distance: 150 m, the carrier gas pressure: 4.0 kgf / c.
m ² G, coke powder particle size: 3.0 mm or less. The results were as follows. That is, the coke moisture content [wt.
%]: 14 wt. %, The transfer condition is not possible, and the coke moisture content [wt. %]: 12 wt. %, The transfer condition is not possible, and the coke moisture content [wt. %]: 10 wt. %, The transport condition is acceptable, and the coke moisture content [wt. %]: 8w
t. %, The transport condition is good, and the coke moisture content [wt.
%]: 6 wt. %, The transport condition was excellent. As is clear from the results of the transport test, the water content of the coke is 10 watts.
t. %, Ie, 14, 12 wt. In%,
The coke cannot be pumped. On the contrary,
Coke moisture content is 10 wt. %, Ie, 8,
6 wt. %, The coke is pneumatically delivered in good condition.

FIG. 2 is a diagram showing another embodiment of the method of drying coke and the method of blowing it into a furnace according to the present invention. As shown in FIG. 2, in the method for drying coke and the method for blowing it into a furnace according to the present invention, coke having a particle size of about 5 mm or less and having a water content of about 10 to 14% is stored by a dump truck 4 in a storage hopper / It is transported to a place where the drying device 1 is located. In the vicinity of the storage hopper / drying device 1, there is provided a receiving hopper 7 for containing wet coke transported by a dump truck. A receiving conveyor 8 is provided extending from below the receiving hopper 7 to above the storage hopper / drying device 1.

A coke blowing device 3 is provided below the storage hopper / drying device 1.
Is provided with a blowing air supply line 5. An exhaust gas duct 9 is attached above the furnace 6. A hot air recovery machine 10 that recovers heat of the exhaust gas is installed in the exhaust gas duct 9. Further, a line for sending the drying gas 12 is provided at a required position near the furnace, and a flow control valve 11 for adjusting the flow rate of the drying gas is provided. The above-mentioned hot air recovery machine may be set on the drying gas line 14 for sending the drying gas. At a predetermined position of the drying gas line 14, a temperature control valve 13 for further controlling the temperature of the gas is provided.

The drying gas line 14 sends a drying gas having a temperature controlled by a temperature recovery device, a flow control valve, a temperature control valve, and the like, into the storage hopper / drying device 1. In addition to the hot air recovery machine that recovers heat from the exhaust gas duct described above,
For example, a hot air recovery machine 1 that recovers heat from a slag pan 13 as a waste heat source not used around the melting furnace
4 and 15 may be provided.

As shown in FIG. 2, the coke having a particle size of about 5 mm or less and having a water content of about 10 to 14%, which is transported by the dump truck 4 to a place where the storage hopper / drying apparatus 1 is provided, is firstly obtained. It is stored in the receiving hopper. The hydrated coke stored in the receiving hopper is received by the receiving hopper 7.
Is moved by a receiving conveyor 8 extending upward from above the storage hopper / drying device 1 and loaded into the storage hopper / drying device 1 from above. In the storage hopper / drying apparatus 1, the water-containing coke is stacked, mixed if necessary, and moves slowly downward.

Further, the heat of the exhaust gas duct is recovered by a hot air recovery machine 10 for recovering heat from an exhaust gas duct 9 mounted above the furnace 6, and the drying gas provided at a required position near the furnace is removed. The temperature of the sending line is increased. In addition, heat is recovered from a slag pan located at another location near the furnace, increasing the temperature of the line sending the drying gas. The drying gas passing through the drying gas line is controlled to a predetermined temperature by the flow control valve 11 for controlling the flow rate of the gas and the temperature control valve 13 for controlling the temperature of the gas. Sent within 1.

The coke dried in this manner to a moisture content of 8% or less passes through the blowing air supply line 5 by the coke blowing device 3 provided below the storage hopper / drying device 1 to the furnace 6. It is blown in.

As described above, according to the method of the present invention, coke having a high water content is not scattered, so that it can be transported in large quantities by a dump truck, and furthermore, the water-containing coke temporarily stored in the receiving hopper is With the receiving conveyor, it can be charged into the storage hopper / drying device 1 in a short time. At this time, if a plurality of storage hoppers / dryers 1 can be used, a larger amount of coke can be moved quickly, and coke can be charged into the plurality of storage hoppers / dryers 1 in a short time. Can be. Therefore,
It can be blown into the furnace by air transport in the same way as expensive coke breeze with a water content of 2% or less.

[0049]

According to the present invention, a special drying facility for drying and a special transportation means such as a tank lorry are not required, a large space is not required for receiving, and the cost can be reduced. A method for drying and a method for blowing into a furnace can be provided, and the industrial use value is high.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of a method of drying coke and a method of blowing coke into a furnace according to the present invention.

FIG. 2 is a diagram showing another embodiment of the method of drying coke and the method of blowing it into a furnace according to the present invention.

FIG. 3 is a diagram showing a conventional method of receiving and blowing coke breeze.

[Explanation of symbols]

 1. Storage hopper / dryer 2. Coke 3. 3. Coke powder blowing device Dump truck 5. Insufflation pneumatic line 6. Furnace 7. 7. Receiving hopper 8. Receiving conveyor Exhaust gas duct 10. Hot air recovery machine 11. Flow control valve 12. Drying gas 13. Temperature control valve 14. Dry gas line 15. Hot air recovery machine 16. Temperature control valve

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) F23K 3/02 301 F23K 3/02 301 (72) Inventor Toshimichi Maki 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Japan F-term (reference) in Kokan Co., Ltd. 4H012 RA02 RA05 4K001 AA10 BA23 BA24 CA09 4K015 AD00 AD05 4K070 AC21 AC32 AC36 CE04 DA01

Claims (17)

[Claims] 1. 10% having a predetermined particle size, which is easy to transport
Receiving the high-moisture-content fine powder in at least one storage hopper, and drying the powder in the storage hopper to a predetermined moisture content in a state that can be pneumatically transported through a pipe into a furnace. How to dry fine powder. 2. A material having a predetermined particle size which is easy to transport.
Receiving the fines having a moisture content of 14% in at least one storage hopper and drying in the storage hopper to a predetermined moisture content that is pneumatically transportable through a pipe and into a furnace. How to dry fine powder. 3. The storage hopper comprises a plurality of storage hoppers, and the plurality of storage hoppers are combined to dry the fine powder so as to be continuously injected into the furnace. The method for drying a fine powder according to claim 1, wherein the method comprises the steps of: 4. The method for drying a fine powder according to claim 1, wherein the drying of the fine powder is performed by compressed air. 5. The method for drying a fine powder according to claim 1, wherein the drying of the fine powder is performed by using recovered waste heat. 6. The method according to claim 1, wherein the predetermined particle size is about 5 mm or less, and the predetermined water content is less than 10%.
A method for drying a fine powder according to any one of claims 1 to 5. 7. The storage hopper according to claim 1, wherein the fine powder having a high water content of 10% or more or the fine powder having a water content of 10 to 14% is conveyed. 2. The method for drying a fine powder according to claim 1. 8. The method for drying fine powder according to claim 1, wherein the fine powder is coke. 9. The method for drying a fine powder according to claim 1, wherein the fine powder is coal. 10. The method for drying a fine powder according to claim 1, wherein the fine powder is a metal. 11. A particle having a predetermined particle size, which is easy to transport.
% Fine powder having a high water content of at least 1% is received in at least one storage hopper, and dried in the storage hopper to a predetermined moisture content in a state capable of being pneumatically transported through a pipe into a furnace. A method of blowing the fine powder into the furnace, wherein the fine powder is blown into the furnace by a pneumatic facility installed below the storage hopper. 12. A particle having a predetermined particle size which is easy to transport.
Receiving fine powder having a moisture content of １４14% in at least one storage hopper, in said storage hopper, drying to a predetermined moisture content ready for pneumatic transport through pipes and into a furnace; A method of blowing the fine powder into the furnace, wherein the fine powder is blown into the furnace by a pneumatic facility installed below the storage hopper. 13. The storage hopper includes a plurality of storage hoppers, and the plurality of storage hoppers are combined to dry the fine powder so as to enable continuous injection into the furnace. 13. The method according to claim 11, wherein:
The method for blowing fines into a furnace according to the above. 14. The method according to claim 14, wherein the predetermined particle size is about 5 mm or less;
The method according to claim 1, wherein the predetermined moisture content is less than 10%, and the drying of the fine powder is performed by air and / or high-temperature air heated by recovered waste heat.
12. The method for blowing fine powder into a furnace according to 0 or 11. 15. The method for blowing fine powder into a furnace according to claim 14, wherein the fine powder is coke. 16. The method for blowing fine powder into a furnace according to claim 14, wherein said fine powder is coal. 17. The method according to claim 14, wherein the fine powder is a metal.