JPS6026397Y2 - Kyupora's powder blowing equipment - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a device for blowing powder and granules such as pig iron powder, pulverized coal, coke please, ferrosilicon, and graphite into a cupola.

Conventionally, this type of device has an injection pipe 4 installed in an air blowing branch pipe 3 connected to a tuyere 2 of a cupola 1, as shown in FIG. Powdered graphite is transported using compressed air,
It is known that the carbon content of the molten metal is increased by blowing it into the cupola 1 from a nozzle 6 at its tip.

Note that 7 indicates a wind box.

On the other hand, cast products formed using molten metal generate a large amount of piglet sludge during subsequent machining, and this slag is reused in cupolas.

By the way, if the soybean powder is charged from the top of the furnace for this reuse, a considerable amount of it will be blown up to the top of the furnace before it is melted, and will be sucked into the flue along with the exhaust gas and accumulate, which will only worsen the yield. This results in inconveniences such as increased ventilation resistance in the furnace and hanging on shelves.

Therefore, instead of this, charging is done in a solid form by compressing it under high pressure or using a binder, but this not only takes time to form but also complicates the operation of the furnace. This may cause other inconveniences.

Therefore, instead of these, use the injection pipe 4 described above.
They tried to blow out radish powder instead of graphite by using a radiator, but since the nozzle 6 was oriented downward, the radish powder, along with the compressed air, was close to the pool of molten metal melted in the dissolution zone. This has the disadvantage that the molten metal is blown out in the opposite direction, resulting in a drop in the temperature of the molten metal, and to prevent this disadvantage, the amount of running coke must be increased to raise the molten metal temperature in advance. .

Therefore, the object of this invention is to provide a powder blowing device that can supply powder and granular material such as pig iron powder into the interior of a cupola from an injection pipe without causing the above-mentioned drawbacks. It is something to do.

In this invention, in order to achieve the above-mentioned purpose, the nozzle of the injection pipe is bent upward toward the approximate center of the dissolution zone located above the grain.

Examples of the drawings will be described.

An embodiment of this invention is shown in FIG. 2, and the same parts as the conventional one are given the same reference numerals.The difference in this invention from the conventional one is that the nozzle 16 of the injection pipe 14 is melted. It is bent upward toward approximately the center P of the band 8.

Then, such an injection pipe 14 is fixed to a mounting lid 9 fixed to a flange of the blower branch pipe 3.

Note that 12 is a viewing window of the tuyere 2, and 13 is a water cooling jacket.

In the above-mentioned one, the injection pipe 1
4. Transfer the pig iron powder using conveying air made of compressed air.
When air, soybean flour, and air are supplied in pulses at regular intervals and blown into the cupola 1 from the nozzle 16, these soybean flour and air are supplied into the cupola 1 from the tuyere 2. Combined with the rising hot air, the nozzle 15
immediately reaches the superheating zone 10 just below the melting zone 8,
The cod daikon powder is dissolved, and the conveying air promotes the combustion of the coke, so that the melting temperature is not lowered by the conveying air and the soybean flour, and the drop in the tapping temperature in the hot water pool 11 is thereby reduced. becomes.

Using the device based on this invention and the device equipped with the nozzle 26 shown in Fig. 4 (hereinafter referred to as a comparative example), an experiment was conducted to blow out pig iron powder under the furnace operating conditions described later, and the amount of air discharged during that period was As a result of investigating changes in pig iron temperature, the values were changed as shown in the graph shown in Figure 5.

In this case, the difference between this invention and the comparative example is that the nozzle 1
6.26, the nozzle 16 is bent upward at an inclination angle α=500 with respect to the axis 1-1 of the tuyere 2, whereas the nozzle 26 is bent upward at an inclination angle α=500. There is.

In both cases, the tuyere 2 has an inclination angle of β=5° with respect to the horizontal line.
with the inner diameter of the pipe 14.24 ≠
52 rML, and to explain the main operating conditions, the feed rate of pigtail powder is 990 kg/hr, and the operating conditions are 7.
The total weight was 6.720 kg because the experiment was carried out for a certain period of time.
If 0 Orran Hg pressure at 500°C.

In Fig. 5, the solid line I shows the case of this invention, and the chain line ■ shows the case of the comparative example.During the experiment, no additional coke was charged to maintain the tapping temperature, but the The running coke and metal were charged several times, so the temperature drop curve was not constant.

From this experiment, it was found that the reduction in the tapping temperature due to this design was smaller than that according to the comparative example.

In the above, additional coke was not charged, so
It has been found that the tapping temperature decreases due to the melting of the pig iron powder, but how much additional coke is required to prevent this drop in the tapping temperature? FIG. 6 shows the results of an experiment to determine whether this is the case.

Therefore, in this experiment, using this idea and the comparative example, the range of tapping temperature was approximately varied for three ways: operating the furnace by blowing out pig iron powder, and operating the furnace without blowing out pig iron powder. Additional coke was charged to maintain a constant temperature of 1540 to 1570°C.

The tapping temperature at this time is shown in the upper column of FIG. 6, and the amount of coke required for this is shown over time in the lower column of the same figure.

In the same figure, the graph of this invention and the comparative example is the solid line 11.
In addition to the dashed line (■), the case of no blasting of pigtail powder is shown as a dotted line (■).

In this experiment, the operating conditions other than the supply of added coke were the same as in the case of FIG. 5.

As can be seen from this graph, the total amount of added coke required for 7 hours during the experiment was 1,300 kg with this design, 1,850/9 in the comparative example, and 1,070/9 in the case without supply.

Therefore, in order to blow and melt about 7 tons of pig iron powder without lowering the tapping temperature, this design uses 1300-1
It can be seen that while it is sufficient to increase the amount of chase coke by 9 to 070=230, the comparative example requires 1850-1070=780 kn.

Note that the above results indicate that the inclination angle α of the nozzle 16 of this invention
It has been found that it is sufficient that the angle is within the range of 50 to 60°.

This idea is as described above, and since the nozzle of the injection pipe installed in the tuyere is bent upwards toward the approximate center of the dissolution zone located above the tuyere, the piggyback powder is produced as a granular material. For example, when used, it prevents the tap temperature from dropping, so less coke is required to maintain the tap temperature, and at the same time, the coke powder is blown up to the top of the furnace. Therefore, the coke can be blown out as it is without the need for extra steps such as solidification to prevent this, and the ratio of the amount of raw metal and coke flour to the amount of running and chasing coke can be reduced. That is, the coke ratio is small and the amount of pig iron tapped can be increased.

On the other hand, if pulverized coal or coke pleat is used as the powder, the hot air supplied from the slats into the cupola will rise and diffuse very effectively, so the components can be controlled by reducing the coke ratio and carburizing. can be carried out quickly, and the rapid combustion of the powder and granules increases the amount of dissolved metal, thereby increasing the operating rate.

Furthermore, even if other powders or granules are used, the same effects as those described above can be expected.

[Brief explanation of drawings]

Fig. 1 is a partially longitudinal front view of an example of a conventional cupola powder/granular material blowing device, Fig. 2 is a partially longitudinal front view showing the operating state of an embodiment of this invention, and Fig. 3 is a summary of the previous example. FIG. 4 is a similar drawing of a conventional model for the same part as FIG. 3, and FIG. Temperature comparison graph,
FIG. 6 is a comparison graph showing the amount of coke consumed by this invention and the conventional one during the pig dust blowing operation and during the non-blowing operation. 1... Ki, 1 Pora, 2... Tuyere, 3.
...Blower branch pipe, 5...Supply pipe, 14...
...Injection pipe, 16...Nozzle.

Claims (1)

[Scope of utility model registration request] In the cupola siding and the ventilation branch pipes that are continuous with this siding,
In a powder blowing device equipped with an injection pipe for blowing powder, the injection pipe is fixed to the lid of a blower branch pipe, and the nozzle is bent upward so as to face approximately the center of the dissolution zone located above the slats. A cupola powder blowing device characterized by: