JPH05124727A - Blow-in device for pulverized/granulated substance - Google Patents

Abstract

PURPOSE:To prevent a nozzle from clogging by coagulation of pulverized/ granulated substance likely to occur when blowing-in is stopped. by providing a counter-feed line in a pulverized/granulated substance blow-in device. CONSTITUTION:In a device to blow in a pulverized/granulated substance from an injection tank 1 into a blast furnace B, a valve 4b is closed when blowing-in of the substance is to be stopped, and a valve 5b on a booster line 5 and one on a feed path 4a are shut when the substance in a feed path 4 has gone. At this stage, the substance remains in a supply nozzle 3, and then a valve 6a on a counter-feed line 6 is opened to blow in an inert gas to the tip of the supply nozzle 3, and the substance 2 remaining in the nozzle 3 is pushed back into the injection tank 1, and valve 6a is shut when the substance 2 in the nozzle 3 has gone.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blowing device used for blowing a powder or granular material such as pulverized coal into a supply end of a blast furnace or the like, and particularly to prevent clogging of a powder or granular material blowing nozzle of the device. To do.

[0002]

2. Description of the Related Art A blowing device for blowing pulverized coal or ore powder (hereinafter simply referred to as powder or granular material) to the supply end of a blast furnace or the like is
In general, an injection tank that contains the granular material,
The injection tank has a structure provided with at least one powder-and-particles-supplying nozzle that has a role of feeding the powders and particles into a blast furnace. Reference is made to Japanese Patent Publication No. 1-54246.

[0003]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention In the conventional type blowing device as described above, the powdery or granular material supply nozzle arranged therein is connected to a feeding path connected to the tuyere of the blast furnace,
When injecting the powder and granules in the injection tank into the blast furnace through the powder and granule supply nozzle and the feed path connected to the nozzle, high-pressure air is supplied from a booster line separately provided in the path, whereby the inside of the injection tank is supplied. Of the powder and granules to the blast furnace, while stopping the blowing of the powder and granules, the shutoff valve provided at the connection between the powder supply nozzle of the blowing device and the supply path is first closed, and then the supply path is closed. It was usual to operate by shutting off the shut-off valve provided in the vicinity of the tuyere of the blast furnace when all of the powder inside was blown into the blast furnace.

By the way, in the conventional blowing device, when the supply of the powder or granules is stopped for a long time, the powder or granules may aggregate in the area to cause nozzle clogging, which makes it difficult to resend the powder. there were. Therefore, in the past, measures such as keeping heat in such areas were taken, but it has not yet been completely prevented from agglomerating powder particles in the supply nozzle. It was the current situation that they needed expenses. In addition, there is also an attempt to send the powder in the nozzle back into the injection tank by using a booster line separately provided in the transport path of the powder, but in this case, the oxygen concentration in the injection tank is Since it rises, if the powder or granular material is pulverized coal, there is a risk of ignition or explosion, which is not a practical solution.

It is an object of the present invention to propose a blowing device capable of effectively preventing the clogging of the supply nozzle, which has been unavoidable in the past in the device for blowing the powder or granular material contained in the injection tank to the supply end of a blast furnace or the like. Is the purpose of.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to an injection device having an injection tank for containing powder and granules, and at least one powder and granule supply nozzle for blowing the powder and granules in the injection tank to a supply end. The powdery-particles blowing device is characterized in that a back-feeding line for discharging the powdery-granular material in the nozzle into the injection tank is provided at the tip of the supply nozzle.

FIG. 1 shows an example in which the blowing device according to the present invention is applied to a blast furnace. In the figure, numeral 1 is an injection tank and 2 is an injection tank 1.
Granules such as pulverized coal contained in the inside, 3 is a granules supply nozzle for feeding the granules 2 to the blast furnace B, and 4 is arranged between the granules supply nozzle 3 and the blast furnace B In the feeding path, one end of the feeding path 4 is connected to the tuyere of the blast furnace B via the valve 4a, and the other end is connected to the tip of the supply nozzle 3 via the valve 4b. Further, 5 is a booster line separately provided in the feeding path 4, and in this booster line 5, a check valve 5a and a valve 5b for controlling the supply and stop of high pressure air are arranged. Reference numeral 6 is a back-feeding line for discharging the powdery or granular material 2 remaining in the supply nozzle 3 into the injection tank 1. In the back-feeding line 6, a high-pressure inert gas (for example, nitrogen gas) flows backward. A check valve 6a for preventing the above and a valve 6b for controlling the supply and stop of the gas are arranged. Further, 7 is a fluidized bed (separation plate) arranged in the injection tank 1, and 8 is a fluidized bed forming line for forming a fluidized bed of the granular material 2, and an inert gas ( Here, a valve 8a for controlling the supply and stop of the line 6 and the gas supply source is shown as an example.

[0008]

When the powder or granular material 2 in the injection tank 1 is blown into the blast furnace B, first, the valve 6 in the line 6 is used.
With b closed, the valves 5b and 4a are opened, high-pressure air is supplied from the booster line 5 into the feeding path 4, and the feeding path 4 is blown. After a certain period of time, when the valve 4b is opened, the powdery particles 2 in the injection tank 1 are blown into the blast furnace B through the supply nozzle 3 and the supply passage 4. At this time, the powder 2 in the injection tank 1 is fluidized, and an inert gas is constantly supplied through the line 8 so as to keep the pressure in the injection tank 1 constant.

In order to stop the blowing of the powder or granules, first, the valve 4b is closed, and when the powder or granules in the feed passage 4 are exhausted, the valve 5b of the booster line 5 and the valve of the feed passage 4a are closed. close. At this stage, the powder particles 2 remain in the supply nozzle 3 as shown in FIG. 2, but in the present invention, the valve 6b of the reverse feed line 6 is opened to the tip of the supply nozzle 3 as the next operation. An inert gas is blown into the nozzle 3 to push back the powder or granules 2 remaining in the nozzle 3, and the valve 6 is closed when the powder or granules 2 are exhausted from the nozzle 3 as shown in FIG.

According to the present invention, the powder / powder blowing device is provided with the back-feeding line 6 and when the blowing of the powder / granule 2 is stopped, all the powder / granule 2 remaining in the nozzle 3 is discharged into the injection tank 1. Since this is done, there is no humor that causes nozzle clogging due to the agglomeration of the powder or granules 2 and smooth blowing of the powder or granules can be performed again.

[0011]

As described above, according to the present invention, the nozzles of the supply nozzles arranged in the injection tank are completely closed, and stable blow operation can be realized. Therefore, the number of lines blown to the supply end of a blast furnace or the like can be reduced. It is possible to always secure a predetermined blowing amount. Further, according to the present invention, since the maintenance of the supply nozzle is little, the cost required for it can be reduced.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of a blowing device according to the present invention.

FIG. 2 is a diagram showing a state in which powder particles remain in a supply nozzle.

FIG. 3 is a diagram showing a state in which powder particles remaining in a supply nozzle are extruded into an injection tank.

[Explanation of symbols]

 1 Injection Tank 2 Powder and Granules 3 Powder and Granules Supply Nozzle 4 Feeding Route 5 Booster Line 6 Reverse Feeding Line 7 Fluidized Bed 8 Fluidized Bed Forming Line B Blast Furnace

Claims (1)

[Claims] 1. A blowing device comprising an injection tank for containing powder and granular material, and at least one powder and granular material supply nozzle for blowing the powder and granular material in the injection tank to a supply end through a feeding path. A powder-blowing device for blowing powder, characterized in that a back-feeding line for discharging powder that has stagnated in the nozzle into the injection tank is provided at the tip of the body supply nozzle.