JP2000129326A - Device for discharging reduced iron - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reduced iron discharging device that the structure of a cooling water passage is simple and the fear of cooling water leakage is reduced and the generation of breaking trouble of a bolt fitting a divided blade to a lug for fitting the blade on a rotary shaft can be reduced. SOLUTION: On the outer periphery in the attaching range of the spiral blade 9 on the water-cooled rotary shaft 3 having the cooling water passage for cooling only the shaft portion with the cooling water and having simple structure, a coating layer 12 composed of monolithic refractory having high heat conductivity, is formed to embed the lugs 3a for fitting the blade projecting on the outer periphery of the rotary shaft 3, the bolts 10 and nuts 11 for fitting the divided blade 9a to this lug 3a for fitting the blade and the base portion at the rotary shaft 3 side of the spiral blade 9. Since the bolt 10 is shielded from the high temp. atmosphere and further, the bolt 10 is held with the high strength by the cooling effect with the cooling water through the coating layer 12, the breaking trouble of the bolt 10 is reduced, and since the structure of the cooling water passage is simple, the fear of cooling water leakage is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a reduced iron discharging device, and more particularly, to a continuous cooling device for a long period of time by reducing a breakage trouble of a bolt for mounting a plurality of divided blades on the outer periphery of a water-cooled rotary shaft. It belongs to the technical field of a reduced iron discharger which is made possible.

[0002]

2. Description of the Related Art As is well known, in a moving bed type reduction furnace,
A reduced iron discharge device is incorporated. Since the reduced iron discharge device according to the conventional example 1 is rotated in a high-temperature atmosphere of up to 1200 ° C. and discharges the reduced iron out of the furnace, the water-cooled rotating shaft of the reduced iron discharge device is provided with a cooling water. Spiral blades that are cooled by water and are spirally mounted on the outer periphery of the water-cooled rotary shaft are formed of a heat-resistant material, and are protruded from the water-cooled rotary shaft to absorb thermal expansion. A plurality of divided blades are fixed with bolts and nuts to form a continuous spiral blade.

Hereinafter, the reduced iron discharging apparatus according to the prior art 1 will be described with reference to FIG. 3 which is a schematic sectional configuration explanatory view showing a cross section of a main part of a moving bed type reduction furnace.
Numeral 0 denotes a moving bed type reduction furnace. Above the hearth 21 of the reduction furnace 20, a reduced iron discharge device 1 described later, which is rotated by a driving device (not shown), is provided. This reduced iron discharge device 1 is a cylindrical water-cooled rotary shaft 3 having hollow portions supported at both ends via bearings 2b in bearing boxes 2a provided on a frame 2 that covers the upper side of the reduction furnace 20. A plurality of blade mounting lugs 3a projecting from the outer periphery of the water-cooled rotary shaft 3 at predetermined intervals so as to conform to a spiral locus are spirally provided by bolts 10 and nuts 11, and a plurality of The divided blade 9a is composed of a continuous spiral blade 9.

A cooling water supply channel 4a for supplying cooling water into the cooling water flow channel 4a protrudes from an end surface of one end of the hollow portion of the water-cooled rotary shaft 3 at one end. The cooling water flowing out of the cooling water flow passage 4a from the side opposite to the cooling water supply pipe 5 is provided between the core 4 and the inner wall of the hollow portion of the water-cooled rotary shaft 3 by inserting the inserted core 4. The cooling water return flow passage 6 through which the cooling water flows is formed. Further, the cooling water supply pipe 5 is provided with a cooling water drain pipe 7.
That is, the cooling water after cooling the water-cooled rotary shaft 3 flowing back through the cooling water return flow passage 6 passes through the cooling water drain passage 8 formed between the cooling water drain pipe 7 and the cooling water supply pipe 5. The lever is configured to be drained out of the water-cooled rotary shaft 3. In the case of the water-cooled rotary shaft 3, the water-cooling rotary shaft 3 has a flow channel for draining the cooling water from the inflow side, but has a configuration having a one-through flow channel for draining the cooling water flowing from one end side from the other end side. There is also a water-cooled rotating shaft.

[0005] As described above, the reduced iron discharger 1 has a maximum of one.
It is rotated in a high temperature atmosphere of 200 ° C. to discharge the reduced iron out of the furnace. Therefore, the reduced iron discharging device 1 is water-cooled throughout the operation. For example, the spiral blade 9,
The bolts 10 and the nuts 11 are not always sufficiently cooled and become high in temperature, and also cause deterioration of the material. Therefore, for example, SUS304, SUS310, SUS31
Although a bolt and a nut made of a heat-resistant material made of 6 or the like are used, sufficient high-temperature strength cannot be obtained, and breakage occurs in a relatively short period (within 40 days). Therefore,
Each time, it is necessary to stop the operation of the reduction furnace, cool down, and exchange the bolts and nuts, so that there is a problem to be solved that the continuous operation of the reduction furnace cannot be performed.

[0006] In view of such circumstances, research and development have been promoted in order to improve the durability of the reduced iron discharging device by reducing the breakage trouble of the bolt. For example,
US Patent 4,636,127 proposes a reduced iron discharge device (conventional example 2) in which cooling water is supplied not only to a water-cooled rotating shaft but also to a blade to cool the blade.

[0007]

The above-mentioned US Paten
According to the reduced iron discharging device according to Conventional Example 2 disclosed at t4, 636, and 127, not only the water-cooled rotary shaft but also the blades are cooled by the cooling water as described above.
Is considered better than However, the reduced iron discharge device according to the second conventional example has to be complicated as compared with the configuration of the cooling water channel of the reduced iron discharge device according to the first conventional example. In addition to the problem to be solved, the risk of cooling water leakage increases, the maintenance cost of the reduced iron discharger becomes disadvantageous, and the running cost increases.

There is another problem to be solved in that the water-cooled rotating shaft and the blades are both cooled, that is, the hearth is excessively cooled because the whole is a cooling body, and the hearth may be damaged. Was.

Accordingly, an object of the present invention is to adopt the configuration according to the conventional example 1 in which only the water-cooled rotary shaft is cooled to avoid an increase in the risk of leakage of cooling water, and to provide a split blade on the outer periphery of the water-cooled rotary shaft. An object of the present invention is to provide a reduced iron discharging device that can reduce the frequency of occurrence of breakage trouble of a bolt to be mounted.

[0010]

Means for Solving the Problems In order to solve the above-mentioned problems, a feature of the means adopted by the reduced iron discharging device according to claim 1 of the present invention is that it is attached to a moving bed type reducing furnace, A water-cooled rotary shaft rotatably supported by a frame, and a spiral blade with a plurality of divided blades attached to the outer periphery of the water-cooled rotary shaft along a spiral with bolts and nuts, and reduced by rotation. In a reduced iron discharging device for discharging reduced iron in a furnace to the outside of the furnace, the bolt and the nut are covered with an irregular refractory.

A feature of the means adopted by the reduced iron discharging device according to the second aspect of the present invention is that a water-cooled rotary shaft attached to a moving bed type reduction furnace and rotatably supported by a frame is provided. A reduction is provided around the outer periphery of the water-cooled rotating shaft by a bolt and a nut so as to extend along a spiral, and a plurality of divided blades are formed of a continuous spiral blade, and the reduced iron in the reduction furnace is discharged outside the furnace by rotation. In the iron discharging device, a coating layer of an indefinite type refractory is formed on an outer periphery of a region where the spiral blade of the water-cooled rotary shaft is provided so that the bolt and the nut are buried.

A feature of the means adopted by the reduced iron discharging device according to claim 3 of the present invention is that, in the reduced iron discharging device according to any one of claims 1 and 2, The irregular refractory has a power of 13 W / 500 ° C.
It has a thermal conductivity of at least m ° C.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a reduced iron discharging device according to a first embodiment of the present invention will be described with reference to FIG. However, the main configuration of the reduced iron discharging device according to the first embodiment is the same as that according to the above-described conventional example 1, except that the bolt and the nut are covered with an irregular type refractory and a high-temperature atmosphere is formed. Therefore, the same reference numerals are given to those having the same functions and the same functions as those of the above-mentioned conventional example 1, and only the differences will be mainly described.

FIG. 1 shows a main part of a reduced iron discharging device 1 according to Embodiment 1 of the present invention. That is, the reduced iron discharging device 1 includes a plurality of blade mounting lugs 3a protruding from the water-cooled rotary shaft 3, and bolts 10 having divided blades 9a mounted on the plurality of blade mounting lugs 3a so as to be continuous. And the nut 11 and the root portion of the divided blade 9a on the side of the water-cooling rotary shaft 3 are buried in a coating layer 12 made of an indefinite refractory material of a material to be described later formed on the outer periphery of an area where the spiral blade 9 of the water-cooling rotary shaft 3 is attached. The bolt 10 and the nut 11
Is a high temperature reducing and corrosive atmosphere [(CO +
Is obtained by reductive atmosphere) + (Na of H _2, K, and configured to prevent direct exposure to the corrosive atmosphere)] of Cl system.

The irregular refractory contains 84 Wt% of silicon carbide, and is 13.3 W / m ° C. at 500 ° C.
Having a high thermal conductivity of

The coating layer 12 made of silicon carbide which covers the outer periphery of the water-cooled rotary shaft 3 is formed by the following method. Hereinafter, a method for forming the coating layer 12 will be described. (1) Blade mounting lug 3 provided on the outer periphery of water-cooled rotary shaft 3
A divided blade 9a is attached to a with a bolt 10 and a nut 11. (2) The nut 11 is welded to the bolt 10 to prevent the nut 11 from loosening. (3) While supporting the water-cooled rotary shaft 3 horizontally, the divided blades 9
a is held horizontally so that a paper tube having a thickness of 10 mm or more called a void tube is fixed along the side surface of the lower divided blade 9a. Stuff the refractory fiber into the gap. (4) Pour in irregular refractories and solidify while applying vibration. (5) Rotate the water-cooled rotating shaft 3 by 180 degrees and perform the above (1) to (4)
Do the work. The irregular-shaped refractory layer is formed on the outer peripheral surface of the water-cooled rotating shaft 3 in this way, and then fired.

According to the reduced iron discharging device 1 according to the first embodiment, the plurality of blade mounting lugs 3a of the reduced iron discharging device 1 and the divided blades 9 are attached to the plurality of blade mounting lugs 3a.
a and bolts 1 and nuts 1 in which
1 means that the inner wall of the hollow part of the water-cooled rotary shaft 3 is not only cut off from the high-temperature atmosphere up to 1200 ° C. by the coating layer 12 but also through the coating layer 12 made of silicon carbide having a high thermal conductivity. There is also an effect that cooling is performed by cooling water flowing through a cooling water return flow passage formed between the cooling water flow path and the cooling water flow path.

Therefore, since the strength of the bolts of the reduced iron discharging device according to the first conventional example is maintained much higher than that of the bolts, the frequency of occurrence of breakage trouble of the bolt 10 is lower than that of the reduced iron discharging device according to the first conventional example. . In addition, the spiral blade 9 is cooled by the coating layer 12 as such, which is effective in extending the life of the spiral blade 9. As described above, the spiral blade 9 is also cooled by the coating layer 12 to some extent. However, the hearth 21 is excessively cooled as in the case of the reduced iron discharge device according to Example 2 in which the water-cooled rotating shaft and the blade are both cooling bodies. There is no danger of cooling.

Incidentally, according to the reduced iron discharging apparatus 1 according to the first embodiment, the operation after forming the coating layer 12 on the outer periphery of the water-cooled rotary shaft 3 has been performed for one year or more. However, there is no breakage trouble of the bolt 10. further,
Although the water-cooled rotary shaft 3 is rotating at a high speed of 50 rpm to 100 rpm to discharge the reduced iron out of the furnace,
Due to the excellent abrasion resistance, the appearance of the coating layer 12 is good, so that there is little risk of breakage of the bolt 10, and it can be expected that the bolt 10 can operate smoothly in the future. Of course, the configuration of the cooling water channel of the reduced iron discharge device 1 according to the first embodiment is the same as that of the conventional example 1, and the configuration of the cooling water channel is not complicated as in the above-described reduced iron discharge device of the conventional example 2. In addition, there is no disadvantage in terms of manufacturing cost, and there is no fear that the risk of leakage of cooling water increases.

Further, according to the reduced iron discharging device 1 according to the first embodiment, since the coating layer 12 is formed on the outer periphery of the water-cooled rotary shaft 3 as described above, the water-cooled Excessive cooling by the rotating shaft 3 is prevented, and the heat influence on the hearth 12 can be reduced.
In addition to the effect that the temperature deviation given to the furnace is small and troubles such as hearth separation can be reduced, the effect that the reduction furnace can be operated at a higher temperature has also been derived.

Next, a reduced iron discharging device according to a second embodiment of the present invention will be described with reference to FIG. Will be described with the same reference numerals. However, the difference between the reduced iron discharging device according to the second embodiment and the reduced iron discharging device according to the first embodiment lies in the difference in the shape of the coating layer. Therefore, only the differences will be described below. I do.

That is, the reduced iron discharging device 1 according to the second embodiment is formed so as to protrude from the water-cooled rotary shaft 3 by forming the covering portion 12 having a trapezoidal cross section along the base end of the spiral blade 9. A plurality of blade mounting lugs 3a, a bolt 10 and a nut 11 having split blades 9a mounted on the plurality of blade mounting lugs 3a so as to be continuous, and a water-cooled rotary shaft 3 of the split blade 9a.
In this configuration, the base portion on the side is buried.

According to the reduced iron discharging device 1 according to the second embodiment, the entire outer periphery of the area where the spiral blade 9 of the water-cooled rotary shaft 3 is attached is not covered with the coating layer. A lug 3a, a bolt 10 and a nut 1 having divided blades 9a attached to the plurality of blade mounting lugs 3a so as to be continuous.
1 indicates that the inner wall of the hollow portion of the water-cooled rotary shaft 3 is not only cut off from the high-temperature atmosphere up to 1200 ° C. by the coating portion 12 but also through the coating portion 12 made of silicon carbide having a high thermal conductivity. Since there is also a cooling effect of the cooling water flowing through the cooling water return flow passage formed between the reduced iron and the child, it is the same as the reduced iron discharging device according to the first embodiment.

In the above, an example has been described in which silicon carbide having a high thermal conductivity is used as the irregular refractory for forming the coating layer 12 or the coating portion 12. However, a general refractory having a thermal conductivity of 2 to 3 W / m ° C. or more can block the thermal effect on the bolt, and is a great measure for preventing the occurrence of breakage troubles of the holt. There is an effect, a plurality of blade mounting lugs 3a and bolts 10
And the nut 11 from the high temperature atmosphere,
Since the cooling effect by the cooling water flowing through the cooling water return flow channel through the coating layer can be expected, a certain effect can be expected for preventing the occurrence of the breakage trouble of the bolt. The material of the refractory is not limited.

[0025]

As described in detail above, claim 1 of the present invention
In the reduced iron discharge device according to the present invention, the bolt and the nut are covered with the irregular refractory, so that the bolt and the nut are shielded from the high-temperature atmosphere by the irregular refractory, There is a cooling water cooling effect for cooling the water-cooled rotary shaft, and in the reduced iron discharging device according to the second aspect of the present invention, the bolt and the nut are buried on the outer periphery of the area where the spiral blade of the water-cooled rotary shaft is attached. Since the coating layer of the irregular-shaped refractory is formed, the bolt and the nut are shielded from the high-temperature atmosphere by the coating layer of the irregular-shaped refractory, and the water-cooled rotating shaft through the irregular-shaped coating layer is cooled. There is a cooling effect of cooling water.

Therefore, according to the reduced iron discharging device according to the first or second aspect, the bolt and the nut continue to be held at a high strength, so that the frequency of occurrence of the breakage trouble of the bolt is reduced as compared with the conventional example 1, and Since the structure of the cooling water passage is not complicated as in Example 2, there is an excellent effect that there is no disadvantage in terms of manufacturing cost and there is no fear that the risk of cooling water leakage increases.

Further, according to the reduced iron discharging device of the third aspect of the present invention, the irregular refractory has a capacity of 13 W / 500 ° C. at 500 ° C.
3. Since the heat conductivity is not less than m.degree. C., the bolts and the nuts are cooled more effectively through the irregular refractory, and the bolts and the nuts are maintained with higher strength. There is an excellent effect that the frequency of occurrence of bolt breakage troubles is lower than in the case of (1).

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a main part configuration of a reduced iron discharge device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a main part configuration of a reduced iron discharge device according to a second embodiment of the present invention.

FIG. 3 is a schematic cross-sectional configuration explanatory view of a reduced iron discharging device according to Conventional Example 1, showing a main part of a moving bed type reduction furnace in cross section.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Reduced iron discharger 2 ... Frame, 2a ... Bearing box, 2b ... Bearing 3 ... Water-cooled rotating shaft, 3a ... Blade mounting lug 4 ... Core, 4a ... Cooling water flow path 5 ... Cooling water supply pipe 6 ... Cooling water Return flowing water channel 7 ... Cooling water drainage pipe 8 ... Cooling water drainage channel 9 ... Spiral blade, 9a ... Split blade 10 ... Bolt 11 ... Nut 12 ... Coating layer or coating portion 20 ... Reduction furnace 21 ... Hearth

Claims (3)

[Claims] 1. A water-cooled rotary shaft attached to a moving-bed type reduction furnace and rotatably supported by a frame, and a plurality of bolts and nuts attached to the outer periphery of the water-cooled rotary shaft so as to extend along a spiral. In the reduced iron discharger which consists of continuous spiral blades and discharges the reduced iron in the reduction furnace out of the furnace by rotation, the bolt and the nut are coated with an irregular type refractory. Reduced iron discharge device. 2. A water-cooled rotary shaft attached to a moving-bed type reduction furnace and rotatably supported by a frame, and a plurality of bolts and nuts attached to the outer periphery of the water-cooled rotary shaft so as to extend along a spiral shape. In the reduced iron discharger, wherein the divided blades are composed of continuous spiral blades, and the reduced iron in the reduction furnace is discharged to the outside of the furnace by rotation, the bolts and nuts are provided on the outer periphery of an area where the spiral blades of the water-cooled rotary shaft are attached. A reduced iron discharge device, wherein a coating layer of an irregular type refractory is formed so as to be buried. 3. The refractory according to claim 1, wherein said refractory is 13
The reduced iron discharging device according to claim 1, wherein the reduced iron discharging device has a thermal conductivity of W / m ° C. or more.