JP6601046B2 - Screw conveyor for material discharge in blast furnace - Google Patents

Description

The present invention, when the rest wind in blast furnace operation, in order to secure a working space by reducing the raw material level in the blast furnace, it relates to screw conveyors for discharging out of the furnace by scraping the raw material in the blast furnace .

  When the blast furnace is stored for a long period of time or when the staves installed inside the furnace are replaced for the purpose of protecting the blast furnace iron skin, the scale level is usually reduced to lower the raw material level in the blast furnace. .

  However, there is a limit to the raw material level that can be lowered by scale-down operation.For example, when it is necessary to lower the raw material level to a level higher than the limit when changing the stave, the raw material in the blast furnace is mechanically scraped to the furnace. It is necessary to discharge outside.

  Therefore, for example, in Patent Document 1, a portable loader is inserted from one tuyere and a portable conveyor is inserted into the blast furnace from the other tuyere, and the coke that is scooped by the portable loader is moved out of the furnace by the portable conveyor. A method and apparatus for discharging is disclosed.

  Moreover, in patent document 2, after dropping a raw material to the height of a tuyere and blowing it off, high pressure water is injected to the raw material, and then the raw material is scraped out of the furnace from a discharge port opened at the bottom of the furnace wall. A method is disclosed.

  Moreover, in patent document 3, after reducing scale reduction, the club bucket is lowered from the upper part of the furnace port to grab the raw material in the blast furnace, and the grabbed raw material is raised to the tuyere part, from the tuyere part to the inside of the furnace. A method and apparatus for supplying an inserted discharge chute and discharging it out of the furnace is disclosed.

  In Patent Document 4, an opening is provided in the lower part of the shaft of the blast furnace and in the furnace wall near the upper and lower sides, and after the raw material above the opening is scraped with a hydraulic excavator, the hydraulic excavator is inserted from the opening and the opening is opened. A method of discharging the lower raw material is disclosed.

  However, since the methods and apparatuses disclosed in Patent Documents 1 to 4 are all used to carry out the raw material in the blast furnace after the blast furnace is blown off, they cannot be applied to an operating blast furnace.

  Moreover, since all the methods disclosed in Patent Documents 1 to 4 carry out the raw material in the blast furnace after the blast furnace is blown off, the discharge of the raw material in the furnace during the long-term storage operation of the blast furnace or when the stave is replaced. The time required for work becomes longer. Furthermore, a cooling function is not required for the appliances and devices used, and no consideration is given to cooling.

JP-A-56-23205 JP 58-9904 A JP-A-1-177308 JP-A-9-287010

  The problem to be solved by the present invention is that the raw material in the blast furnace has been discharged after the blast furnace has been blown up conventionally, so it cannot be applied to the operating blast furnace, and the discharge operation of the raw material in the blast furnace It takes a long time to complete.

  The present invention makes it possible to insert a screw conveyor from the tuyere part during the operation of the blast furnace during the long-term storage operation of the blast furnace or when replacing the stave to scrape the raw material in the blast furnace and discharge it outside the furnace. Thus, it is an object to make it possible to shorten the discharge time of the raw material in the blast furnace.

To achieve the above objective,
The screw conveyor of the present invention for scraping the raw material in the blast furnace and discharging it outside the furnace,
Cooling water is passed through the screw shaft and screw wings constituting the screw conveyor to cool the screw shaft and screw wings,
The most important feature is that the screw blades have a structure capable of supplying and discharging water for each screw pitch .

The screw conveyor of the present invention is
After putting the blast furnace into a resting state,
The raw material in the blast furnace is scraped out from the tuyeres in the resting state and discharged outside the furnace .

  According to the present invention, since the raw material in a high temperature state of about 1000 ° C. can be transported, the operation of lowering the raw material level in the blast furnace by discharging the raw material out of the furnace to secure a working space Can be performed in a short time without blowing off.

  According to the present invention, the raw material in a high temperature state of about 1000 ° C. can be scraped out from the tuyere of the blast furnace by inserting the screw conveyor and discharged out of the furnace in a short time. Work space can be secured by lowering the raw material level.

It is a figure explaining the method of discharging | emitting the raw material in a blast furnace using the screw conveyor of this invention, (a) shows before discharge | emission of the raw material in a furnace, (b) shows after discharge | emission of the raw material in a furnace. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the principal part of the screw conveyor of this invention, (a) is a figure explaining the water supply / drainage part to a screw shaft and a screw blade, (b) is a longitudinal cross-sectional view explaining the structure of a screw shaft and a screw blade, (C) is a cross-sectional view illustrating the structure of a screw shaft and screw blades. It is a figure explaining the off-line test of the raw material scraping, (a) is a view seen from the side direction before scraping, (b) is a view seen from above after scraping, (c) is a view seen from the side direction after scraping. It is a figure. It is a figure explaining the heat-resistant performance test of a screw conveyor.

  In the present invention, during the operation of the blast furnace, the purpose of discharging the raw material in the blast furnace is to insert a screw conveyor cooled by passing cooling water through the screw shaft and the screw blades from the tuyere part in the resting state. This was realized by scraping the raw material and discharging it out of the furnace.

The present invention will be described below.
For example, when the stave is replaced, if the work space in the blast furnace is not sufficient by the reduced scale operation alone, the raw material in the blast furnace is discharged out of the furnace. In order to be able to discharge the raw material in a short time, the inventor considered that a screw conveyor was inserted from the tuyere portion during the blast furnace operation and the raw material was scraped out and discharged out of the furnace.

  In order to scrape the raw material in the blast furnace and discharge it out of the furnace when the wind is not in operation, an off-line test was conducted in which a screw conveyor was inserted from the tuyere to scrape the raw material in the blast furnace. Moreover, since the raw material in the blast furnace during the rest period is a high temperature of about 1000 ° C., the heat resistance performance of the screw conveyor inserted from the tuyere was tested.

[Offline test]
The screw conveyor 3 was inserted 2300 mm from the position of 1430 mm from the upper end at the center position in the width direction of the side wall of the hopper 2 filled with the coke 1 until it was full (the intake portion was in the range of 1000 mm on the front end side) (FIG. 3A). reference).

  Thereafter, the screw conveyor 3 was continuously operated to scrape the coke 1 in the hopper 2 and the state of the coke 1 in the hopper 2 after scraping was confirmed. In addition, since the motor stopped by the trip at the time of operation of the screw conveyor 3, the continuous operation was performed after restarting several times.

  Table 1 below shows the measured weight of the scraped coke, the operating time of the screw conveyor, the weight per hour of the scraped coke, and the volume per hour of the scraped coke. The hourly volume of scraped coke in Table 1 below is a value converted from the coke shape and measured weight in the hopper after scraping, as shown in FIGS. In addition, the dimension shown to FIG.3 (b) (c) is a dimension at the time of the 2nd test.

  It was confirmed by the offline test that a working space can be secured by lowering the raw material level in the blast furnace by inserting a screw conveyor into the tuyere and scraping out the raw material in the blast furnace.

[Heat resistance test of screw conveyor (see Fig. 4)]
The portions of the screw shaft 3a and the screw blade 3b of the screw conveyor 3 are inserted into the heating furnace 4, and the screw blade 3b at the tip of the screw shaft 3a is supported by the brick 6 via the ceramic fiber 5 and heated. The atmospheric temperature inside the furnace 4 was heated to 910 ° C.

For example, as shown in FIG. 2B , the screw shaft 3a has a double tube structure of an inner tube 3aa on the water supply side and an outer tube 3ab on the drain side. The screw blade 3b formed on the outer periphery of the screw shaft 3a has a hollow structure so that the cooling water supplied through the inner tube 3aa is guided and cooled, and then discharged to the outer tube 3ab. ing.

  As described above, the screw conveyor 3a and the screw blades 3b are water-cooled, so that a special heat-resistant steel is not used, for example, SS400, which is a general structural rolled steel, is used, and the screw conveyor has good heat resistance at low cost. 3 can be made. Non-special heat resistant steels include, for example, rolled steel for general structure defined in JIS G 3101, rolled steel for welded structure defined in JIS G 3106, and general stainless steel defined in JIS. .

  Further, when the screw shaft 3a and the screw blade 3b are cooled with the configuration shown in FIG. 2, it is possible to minimize the rise in the temperature of the cooling water until it passes through the screw blade 3b.

  The cooling water is flowed 10 tons per hour from the water supply part 3d attached to the base end side of the screw shaft 3a through the rotary joint 3c inside the screw shaft 3a and the screw blade 3b having the above-described configuration. The surface temperature of the wing 3b was measured.

  As a result of the heat resistance performance test, the surface temperature of the screw shaft 3a and the screw blade 3b is 130 to 190 ° C., and a screw conveyor is inserted into the blast furnace in a closed wind from the tuyere to scrape the raw material at about 1000 ° C. However, it was found that there was no problem in heat resistance.

  Based on the above test results, 2300 mm of the screw conveyor 3 shown in FIG. 2 is inserted from the tuyere portion 12 of the actual blast furnace 11 during the rest period, and the raw material 13 in the blast furnace is scraped out by continuously operating for 2 hours. The status of raw materials in the blast furnace after being discharged out of the furnace was confirmed.

  As a result, by cooling the screw conveyor with about 10 ton / h of cooling water, it was possible to scrape the red-hot raw material without damaging the screw conveyor, and it was confirmed that a working space could be secured in the blast furnace.

The present invention has been made based on the above test results.
That is, according to the present invention, first, as shown in FIG. Then, scan the clew shaft 3a and the screw blade 3b, the inner tube 3aa and passed through the cooling water from the water supply unit 3d, the screw blade 3b, and the screw shaft 3a of the screw conveyor 3 and the outer tube 3ab cooled tuyere 14 (See FIG. 1B).

  Finally, the cooled screw conveyor 3 inserted from the tuyere portion 14 is operated to scrape out the raw material 13 inside the blast furnace 11 and discharge it outside the furnace.

  According to the present invention, since the raw material in a high temperature state of about 1000 ° C. can be scraped from the tuyere of the blast furnace by inserting the screw conveyor and discharged out of the furnace during the rest period, A working space can be secured.

  The present invention is not limited to the above example, and it goes without saying that the embodiments may be changed as appropriate within the scope of the technical idea described in each claim.

For example, scan screw blade 3b of the clew conveyor 3 In addition to the cooling by the same route, a separate room screw blade 3b for each pitch, as shown in FIG. 2 (b), each pitch of the cooling water to be passed through It is also possible to supply water independently.

  If it does in this way, it will become possible to suppress the temperature rise of the cooling water which cools screw wing 3b to the minimum.

3 Screw conveyor 3a Screw shaft 3aa Inner tube 3ab Outer tube 3b Screw feather 11 Blast furnace 12 Tail 13 Raw material

Claims (2)

A screw conveyor that scrapes the raw material in the blast furnace and discharges it outside the furnace,
Cooling water is passed through the screw shaft and screw wings constituting the screw conveyor to cool the screw shaft and screw wings,
A screw conveyor for discharging raw materials of a blast furnace, wherein the screw blades have a structure capable of supplying and discharging water for each screw pitch . 2. The screw conveyor for discharging a blast furnace material according to claim 1, wherein the screw conveyor is inserted from a tuyere portion in a quiescent state after the blast furnace is in a quiescent state . 3.

Images