JPH07258649A - Delivering apparatus for granule - Google Patents

Abstract

PURPOSE:To provide a delivering apparatus for granules in which a feeding port for flushing gas and an exhausting port for exhausting the gas after flushing from a pneumatic carriage tank, are attached at the pneumatic carriage tank and the granules are dried in the pneumatic carriage tank to improve the delivering properties. CONSTITUTION:This delivering apparatus 1 for pneumatically delivering granules is composed of a hopper 12 for charging granules, such as raw material coal 14, a pneumatic carriage tank 10 for tentatively storing the granules from the hopper 12 and a pneumatically delivering piping system 13 connected to the pneumatic carriage tank 10. In the delivering apparatus 1, a raw material coal 14 is fed into the pneumatic carriage tank 10 from the hopper 12 through a hopper valve 11, a flushing gas is supplied from a flushing gas-supplying port 16 placed at a lower part of the pneumatic carriage tank 10 to flush the gas under stirring with a stirrer 24. The gas is exhausted from an exhausting port 18 of the flushing gas placed at an upper part of the pneumatic carriage tank 10 through a gas-exhausting valve 19 which has been opened. The granules are dried by this treatment. Then, the gas-exhausting valve 19 is closed and a pneumatic carriage valve 34 is opened to efficiently deliver the granules 14 from the pneumatic carriage tank 10 through a pneumatically delivering piping system 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for transporting powder and granules by air flow, and in particular, for example, when charging raw coal into a coke oven, it is possible to appropriately pipe powder or granules such as coal having moisture. The present invention relates to a transportation device that transports air through a system. Less than,
The present invention will be described by taking a case where raw coal is supplied to a coke oven as an example.

[0002]

BACKGROUND ART As is well known, a coke oven is a heating furnace for carbonizing carbon to produce coke required as a reducing agent during blast furnace operation. Conventionally, in a coke oven, fuel and air are first preheated in a heat storage chamber, and 80% of the whole is fed by a coal car to a coking car, and is charged into the carbonization chamber from the upper part of the furnace to form refractory bricks. Heat stored (1100 to 1300 ℃)
Manufactured a blast furnace coke by carbonizing and carbonizing coal. The carbonization time varies depending on the capacity of the furnace, but usually 10 to
It takes about 20 hours. The coke after the carbonization is extruded to the fire extinguisher truck on the opposite side by an extruder provided on the side of the furnace, and then digested with nitrogen or water.

By the way, most of the refractory bricks constituting this coke oven are silica stone bricks, and although this silica stone brick is excellent in terms of thermal conductivity and formability, its volume change due to temperature change in the furnace is large. Therefore, there is a problem that spalling is likely to occur. That is, when the raw coal is charged, the life of the furnace body is adversely affected due to the occurrence of spalling due to the temperature decrease in the upper part of the furnace body and the excessive load load of the carburized car, which is a heavy object. Also,
There is also an environmental problem due to dust generation when the raw coal is introduced into the furnace interior. Therefore, in recent years, an air flow transportation method has been proposed in which coking coal is supplied to a coke oven without using a coal car. (See JP-A-4-303324)

[0004]

However, it has been found that in the method of pneumatically transporting powder, the water content and surface shape of the granules are important and have a great influence on the transportation ability. That is, the raw material coal in the coke oven is pulverized in the middle, and 80% of the whole is prepared to have a particle size of 3 mm or less. On the other hand, from the viewpoint of storage in the yard and the environment, the attached water content is 8 to 10%. There is a degree. However, if such a large amount of water is contained, problems such as blockage of the piping system tend to occur during air flow transportation. Therefore, the attached water content is controlled to 3% or less by a dryer in the middle process. Therefore, if the facility capacity of the dryer is not sufficient or a trouble occurs, the transportation capacity is significantly reduced, and the operation is greatly affected.

Further, the water vaporized by the dryer may be exposed in the hopper and re-adhere to the raw material coal, and the water content may be increased above a predetermined level to be conveyed, causing a trouble.
Thus, the object of the present invention is to solve the problem caused by moisture as seen in, for example, an air flow transportation system that exhibits excellent characteristics when charging raw material coal into a coke oven, and further improve the transportation efficiency. It is to provide a new air flow transport device that can.

[0006]

According to the present invention, it is particularly advantageous to dry the raw material powder or granules by using the flushing gas in the pneumatic tank constituting the above-mentioned air flow transport device. It turned out to be

[0007] Therefore, the gist of the present invention is to provide a hopper for introducing powder and granular material, an air feeding tank for temporarily storing the powder and granular material from the hopper, and an air flow connected to the air feeding tank. A transportation device for pneumatically transporting a granular material comprising a transportation piping system, wherein the pneumatic tank is provided with a flushing gas supply port for pre-flushing the granular material in the pneumatic tank, and after flushing. A discharge port for flushing gas for discharging the flushing gas to the outside of the pneumatic tank, and drying the granular material in the pneumatic tank to improve transportability. It is a transportation device.

According to a preferred embodiment of the present invention, a moisture measuring means may be provided in the hopper in order to know in advance the amount of moisture of the powdered or granular material to be charged. Further, a suitable stirring device for the charged powder particles may be provided in the pneumatic tank to accelerate the drying.

[0009]

Next, the operation of the present invention will be described more specifically with reference to the accompanying drawings. FIG. 1 is a schematic explanatory view of a powdery or granular material transport device according to the present invention. In the figure, the powdery- or granular-material transporting device 1 is composed of an air-transporting tank 10, a hopper 12, and an air-stream transporting piping system 13.

The hopper 12 installed at the inlet of the pneumatic tank 10 is equipped with a raw material moisture measuring device 15, which measures the adhering moisture content of the fed raw material coal 14 each time,
Remember. On the other hand, the pneumatic tank 10 is provided with a plurality of holes 16 constituting a supply port for flushing gas at the lower end thereof, and an exhaust port 18 is also provided above the hole 16. A bag filter 22 is provided in the exhaust pipe 20 connected to the exhaust port 18, and a hygrometer 35 is provided on the outlet side of the bag filter 22. Pneumatic tank, if desired
A stirring device 24 may be provided in the inside of the device 10. Reference numeral 30 indicates a load cell.

The illustrated example shows an embodiment in which a plug transportation means is incorporated in a powdery or granular material transportation device, and the pipe system 13 is provided with an air knife 42 connected to an air knife gas supply valve 40.

When the hopper valve 11 is closed and the exhaust valve 19 is also closed to supply flushing gas, the flushing gas in the tank becomes a carrier gas for air flow transportation, and the powder is in the piping system 13
Sent to. Next, the flushing gas is stopped, the air knife gas supply valve 40 is opened, and this operation is repeated to carry out the plug transportation. The powder is transported by plugs by appropriately opening and closing the valve in this manner, but the plug transport itself is already known, and a further description will be omitted.

The structure of the hole 16 for blowing the flushing gas is
For example, it may be fine pores having a diameter of 0.5 mm or less, but it is more preferable that the pores are made of a gas permeable porous body using a sintered metal or the like.

A cutout 32 is provided in the lower part of the pneumatic tank 10, and a certain amount of raw coal is cut out by operating the pneumatic valve 34, and the coal is conveyed to the airflow through the piping system 13 to reach the destination. Will be transported to. In particular, in the illustrated example, the air knife gas is supplied from the air knife gas supply valve 40 by intermittently opening and closing the valve to open and close the air knife 42.
In the present invention, 13 is not particularly limited to plug transportation and may be a conventional one.

Further, in the illustrated example, only one air supply tank 10 is shown, but it is also possible to arrange some of them and send them to the same air flow transportation piping system 13 by a valve mechanism as appropriate.
Therefore, the larger the number of pneumatic tanks 10, the more effective.

According to the present invention, a method of gas-drying the particles stored in the pneumatic tank 10 is adopted. However, since the particles have a large surface area, a gas dehumidified in advance is aerated. When this is done, the adhered water vaporizes and the water content can be reduced more quickly.

The efficient way to do this is to widen the range through which the gas passes, which is achieved by, for example, stirring with a stirrer at the same time and measuring the contact between the passing gas and the powder. Furthermore, flushing with a high-temperature gas (inert gas such as nitrogen or argon) promotes vaporization of moisture, so that the attached moisture can be more effectively removed in a short time. At this time, the powders are agitated at the same time, causing friction between the powders. As a result, when viewed microscopically, the corners of the angular powders are removed and the whole is rounded, and the cohesiveness of the powders Decreases, the fluidity of the powder and the angle of repose are improved, and the gas transport property is improved. Additionally, additionally, dehumidification can be effectively performed by frictional heat between powders.

According to the pneumatic transportation method of the present invention, it is possible to control the water content of raw coal by the following procedure. First, when the raw material coal 14 is charged into the hopper 12, the water content is measured by means such as a water content meter utilizing the attenuation of neutrons. Pneumatic tank via valve 11
The amount of the raw material coal 14 charged into the inside 10 can be measured by the load cell 30 provided in the pneumatic tank, and the total amount of water can be calculated from these. Based on this, it becomes possible to previously obtain the required amount and temperature of the flushing gas.
The exhaust valve 19 of the pneumatic tank is opened to feed the raw coal into the hopper, and then the feed valve 11 is closed and then the flushing gas supply valve (not shown) is opened, and at the same time, the agitator is opened.
Rotate 24 to allow dehumidified flushing gas to flow through holes 16 and into air tank.

The flushing gas absorbs moisture while passing through the raw coal, passes through the valve 19 and the exhaust port 18 through the back filter 22 to remove dust, and is exhausted. The humidity at this time is measured by a hygrometer 35. The amount of water removed can be calculated by integrating with the gas flow rate. When the target removal moisture is reached, the exhaust valve is closed and the agitator 24 is stopped to pressurize the tank as it is with flushing gas. If the valve 34 is opened, transportation can be performed as it is. If there is no raw coal in the hopper 12, flushing may be performed with both the hopper valve 11 and the exhaust valve 19 open.

FIG. 2 is a graph showing the relationship between the amount of moisture in the powder (after drying) and the pressure in the pneumatic tank when the air is transported without operating the agitator 24. It can be seen that under constant pressure, the transport amount increases as the water content decreases. FIG. 3 is a graph showing the results when the stirrer 24 is also used (shown by the solid line), but the transport amount is increased in any case as compared with the case without the stirrer (shown by the broken line). This is not only because the water removal efficiency was improved, but also because the surface shape of the powder was changed by stirring to facilitate the flow.

Therefore, according to a preferred embodiment of the present invention,
The raw material coal can be continuously dried and pressed. In addition, even in normal air flow transport that does not rely on plug transport,
The same effect is obtained by a similar mechanism.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Air transportation using the equipment shown in FIG. 1 and the procedure described in the above-mentioned section of operation according to the present invention.
An example of (plug transportation) is shown.

The amount of coal charged into the pneumatic tank is 10 tons,
At that time, the amount of attached water was 3 to 4%. Table 1
As a summary of the conditions, in the case of continuously flowing a flushing gas (nitrogen) of 30 Nm ³ / min at 23 to 25 ° C, and at the same time when the stirrer was rotated at 25 to 35 rpm, the temperature was raised to about 200 ° C. Heated flushing gas (nitrogen) 20 N
Table 2 shows the measured water content and the results of the investigation of its transport capacity obtained when m ³ / min was continuously used and when the stirrer was used at. The solid-gas ratio shown in Table 2 is the transport capacity of the powdery particles at the same carrier gas flow rate.

It can be seen from Table 2 that the water is removed only by flushing, but the water removal becomes more remarkable when the temperature of the flushing gas is raised or a stirrer is used.

Further, as shown in Table 2, the lower the water content, the lower the transportation capacity.
Although the (solid-gas ratio) is improved, as can be seen from the comparison between C and E, the transportation capacity is improved when the agitator is used even if the water content is low. This is because the surface shape of the powdery particles was changed by using the stirrer.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

As shown in the embodiments, the present invention enables the control of water content in the pneumatic tank and the improvement of the transportation capacity by reducing the water content. Furthermore, by installing an agitator inside the air tank, the transport capacity can be improved even with the same water content.

Conventionally, when equipment troubles such as a dryer occur, the moisture charged in the tank for pneumatic transportation fluctuates, and the transportation capacity fluctuates accordingly, which may hinder the operation. However, the method of the present invention made it possible to control the water content during the waiting time.

The present invention uses a knife valve, for example,
An example of the plug transportation in which the carrier gas and the knife air are switched to every other second and the knife air of the same amount as the carrier gas is supplied for transportation is shown, but the invention is not limited to the plug transportation.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a powder transport device according to the present invention.

FIG. 2 is a graph showing a relationship between a gas transportation capacity of a charging raw material coal and a pressure in a gas transportation tank for each attached water content.

FIG. 3 is a graph showing the relationship between the gas transport capacity of coal and the pressure in the gas transport tank, showing the effect of using the stirrer according to the present invention.

Claims (3)

[Claims] 1. A granular material comprising a hopper for charging the granular material, a pneumatic tank for temporarily storing the granular material from the hopper, and a pneumatic transportation pipe system connected to the pneumatic tank. And a flushing gas supply port for flushing powder particles in the air transport tank in advance, and the flushing gas for air transport after the flushing. An apparatus for transporting powder or granules, characterized in that discharge ports for flushing gas to be discharged to the outside of the tank are provided respectively, and the powder or granules are dried in the pneumatic tank to improve transportability. 2. The apparatus according to claim 1, further comprising means for measuring the water content of the granular material prior to supplying the granular material to the pneumatic tank. 3. The powdery or granular material transport device according to claim 1, further comprising a stirrer in the pneumatic tank.