JPS593677B2 - You can't help it. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for effectively recovering waste heat from melting furnace slag, such as blast furnace slag and converter slag, generated during iron and steel manufacturing processes.

Melting furnace slag, such as blast furnace slag and converter slag, is high temperature and has a large amount of waste heat, so it is desirable to recover this waste heat, but with conventional technology, the steam obtained from the recovered waste heat is However, it requires large turbine equipment, and it is difficult to efficiently refine the melting furnace slag and cool it from a liquid state to a solid state.Currently, there is still no effective way to utilize the heat from the melting furnace slag. No collection has taken place.

The present invention has been made in view of the above points, and its purpose is to provide a method for recovering heat possessed by various types of melting furnace slag produced in the iron and steel manufacturing processes. A plurality of rotating bodies having a plurality of rotating bodies are arranged in a direction inclined with respect to the vertical direction so that adjacent rotating bodies overlap in the vertical direction, and an upper surface of each rotating body having an upward velocity component that is forced to rotate. The melting furnace slag is dropped to the side to make it fine, and a cooling fluid is circulated through the circulation route having the tower, etc., and the cooling fluid is forcibly raised inside the tower, and the melting furnace slag is made to fall. Cool the melting furnace slag,
The cooling fluid that has become high in temperature due to this cooling is taken out before or after dustproofing and the heat is recovered by heat removal through heat exchange, and then the cooling fluid that has been cooled by the heat removal is fed into the tower via a circulation route. The present invention provides a method for recovering heat from melting furnace slag.

Hereinafter, the configuration of the present invention will be explained based on the drawings.

In Fig. 1, reference numeral 1 denotes a tower, in the upper part of which a pulverizer 2, which will be described later, is installed, and in the lower part of the tower, a partition wall 3 having a large number of cooling gas ejection holes is inclined. A discharge port 4 is provided in the tower wall on the side of this partition wall.

Particle refining device 2 is connected to furnace slag pan 5 provided at the upper end of tower 1.
When the high-temperature melting furnace slag flows down toward the tower, the melting furnace slag becomes fine particles and falls, and does not come into countercurrent contact with the cooling gas that is continuously introduced from the bottom of the tower 1 by the blower 6. The fine particles are cooled and solidified to a temperature that makes it impossible for them to stick together again.

The cooled and solidified fine particles are discharged to the outside of the tower from the discharge port 4 at the bottom of the tower.

On the other hand, the high-temperature cooling gas that rises to the top of the vehicle while coming into contact with the pulverizing furnace slag is taken out from the top of the vehicle and removed by the dust collector 7, and then sent to the heat exchanger 8 where it is mixed with the heat medium and heat medium. Contact is made via conduit 9.

The heat medium is heated by the high temperature gas and recovers the heat, and also cools the high temperature cooling gas.

This cooling gas is again sent and circulated to the lower part of the structure 1 by the blower 6.

10 is a cooling gas purge pipe.

As shown in Fig. 2, a residual heat recovery chamber consisting of a fixed chamber 12 equipped with a moving bed 11 having a large number of cooling gas ejection holes is provided adjacent to the lower part of the bunroku 1. The structure is such that the melting furnace slag is sent from the lower part of the bunker 1 to the fixed chamber 12, and a part of the cooling gas is sent to the lower side of the moving bed 11, so that heat can be recovered more effectively. There is also.

In addition, as shown in Fig. 3, a residual heat recovery chamber consisting of a rotary kiln 13 is connected to the discharge port 4 at the lower part of the bunraku, and the pulverized melting furnace slag is sent from the lower part of the bunraku 1 to the rotary kiln 13. death,
In some cases, a part of the cooling gas is sent to the rotary kiln 13 so that heat can be recovered more effectively.

As a method for refining the melting furnace slag, a refining device consisting of multiple rotating bodies is used.

That is, as shown in FIG. 4, a plurality of rotating bodies are arranged adjacent to the vertical wall 14, parallel to each other, and so that the longitudinal direction of the rotating body is perpendicular to the flowing down or outflow direction of the melting furnace slag 15. A body 16.16... is provided.

The rotating body 16 is fixed so as to be integral with a rotating shaft that penetrates the wall and is horizontally supported at both ends by bearings provided on the outside of the building, and is connected to the rotating shaft and the shaft from outside the building. It is configured to be able to drive the rotating body 16.

The rotating bodies are arranged in a straight line or in an arbitrary curved line that is inclined with respect to the vertical direction.

In addition, the surface shape of the rotating body includes, for example, a rotating cylindrical surface,
A curved surface such as a portion of a rotating conical surface, a rotating animal surface, a rotating hyperboloid surface, etc. can be employed.

The multi-rotating body constructed in this way is, for example, the first
If the rotating body is composed of a convex curved surface when viewed from the axis, then
The second rotating body has almost the same curved surface as the first one,
It is formed to have a concave shape when viewed from the axis, and the rotating bodies are arranged in parallel so that the first and second rotating bodies mesh with each other with an appropriate gap.

Since all of the rotating shafts arranged in parallel in this way are driven in the same direction of rotation, they pass each other at speeds in opposite directions at the meshing part, and the relative speed is determined by the circumferential speed of rotation of each rotating body. It is the sum of

For the above reasons, in order to avoid interference between the rotating curved surface of the rotating body and the rotating shafts, it is recommended that at least the axis of rotation of the rotating body coincides with the axis of the rotating shaft. This is desirable because it can be determined.

As shown in FIG. 4, the rotating shafts arranged parallel to each other are arranged in a straight line or in an arbitrary curved line with respect to the melting furnace slag 15 flowing vertically downward.

In this case, only the surface area where the circumferential velocity vector of the surface of each rotating body has an upward velocity component is exposed to the falling melting furnace, and the surface area where the circumferential velocity vector has a downward velocity component is located above the rotating body. It is configured so that it is in the shadow of a rotating body or a shielding plate.

Since the temperature of melting furnace slag such as blast furnace slag and converter slag is generally high, it is preferable that the rotating body and rotating shaft exposed to the high temperature atmosphere be made of materials such as heat-resistant cast iron or heat-resistant special steel. be.

In this case, as shown in FIGS. 5 and 6, the rotating body 1
It is preferable that the rotating body 6 is hollow so that a cooling liquid such as cooling water or a cooling gas is passed from the outside into the gap 18 between the rotating body 16 and the rotating shaft 1γ to continuously cool the rotating body.

Incidentally, it is also possible to provide suitable protrusions on the surface of the rotating body 16 to make it easier to make the particles finer.

In addition, as shown in FIGS. 7 and 8, one or more cooling fluid jets 19 are provided in the vertical wall 14, that is, the multi-rotating body support wall, and the jets 19 are arranged between the rotors. It may be arranged above or below the rotating body to cool the rotating body from the outside, prevent melting furnace slag from adhering to the rotating body, and promote grain refinement.

Furthermore, as shown in FIGS. 9 to 12, a large number of holes 20, 20...
... is provided to cool the rotor 16 from the inside by flowing cooling fluid into the gap 18 between the rotating shaft 17 and the rotating body 16, and cooling fluid is supplied from the holes 20, 20... The structure may be such that the melting furnace slag 15 can be made fine by spouting out the melting furnace slag 15.

Here, it is convenient to attach and detach the rotating shaft 17 and the rotating body 16 as separate bodies as part of the outer shell, but it is also possible to configure both the rotating shaft 16 and the rotating body 16 in an integrated structure.

The present invention has the following various effects.

(1) It is possible to effectively recover the sensible heat and latent heat released while the melting furnace slag changes from the molten state to the cooled and solidified state, and the recovered energy can be used for high-pressure steam, electric power, and other heating purposes. I can do it.

(2) Conventional natural and water cooling systems require post-processing processes such as crushing, collecting, pulverizing, and classifying large blocks of solid slag, but in the present invention, it is finely granulated before being discharged. No post-processing process is required.

(3) Since the furnace slag treatment can be carried out continuously and the tower system utilizes natural fall, the plant is small-scale and does not require a vast cooling yard.

(4) Converter slag generally contains 8 to 15% iron, up to 25%, but in the present invention, the handling of the slag is simplified by directly connecting the magnetic sorter to the slag particle discharge section, etc. By controlling the operating conditions of the process, small-diameter and uniform granules can be obtained, which increases the efficiency of magnetic sorting.

(5) A high level of waste heat can be recovered because of the countercurrent cooling system.

In particular, in the present invention, a plurality of rotating bodies each having a horizontal axis are arranged in a row in a direction oblique to the vertical direction so that adjacent rotating bodies ramp in the vertical direction. Since the melting furnace slag is dropped onto the upper surface side of each rotating body that is forced to rotate and becomes fine particles, the melting furnace slag collides with the rotating body at a high relative speed higher than the free fall speed. At the same time, the melting furnace slag that was not sufficiently refined by the collision with the rotating body on the upper stage is further refined by collision with the rotating body on the lower stage, and therefore, the efficiency of grain refinement is high. At the same time, as mentioned above, since the melting furnace slag is dropped onto the upper surface side of the rotating body having an upward velocity component, the melting furnace slag will be given the above-mentioned upward velocity component by the rotating body due to the collision with the rotating body. As a result, the empty time between volumes becomes longer, and the heat recovery rate from the melting furnace slag is improved.

In addition, in the opposing parts of both adjacent rotating bodies, the surfaces of both rotating bodies have circumferential velocities that are opposite to each other, and since the relative speed is constant, even if melting furnace slag adheres to the rotating bodies, When the thickness of the layer of melting furnace slag that has adhered to both adjacent rotating bodies exceeds the gap between both adjacent rotating bodies, the adhered melting furnace slag is subjected to a large shearing force at the opposing part, Therefore, the melting furnace slag attached to the rotating body can be prevented from growing beyond a predetermined level without using a special scraper.

[Brief explanation of drawings]

FIG. 1 is a flow sheet of an apparatus for implementing the method of the present invention, FIG. 2 is a flow sheet showing another embodiment, FIG. 3 is a flow sheet showing still another embodiment, and FIG. 4 is a detailed flow sheet. An explanatory diagram showing one embodiment of the granulating device, FIGS. 5 and 6 are longitudinal sectional views of the multiple rotating bodies used in the granulating device shown in FIG. 4, and FIGS. FIG. 9 is an explanatory diagram of a pulverizing device equipped with cooling fluid jets, FIG. FIG. 12 is an explanatory diagram of a grain refining device having a plurality of multiple rotors shown in FIG. 9. 1...Text omitted, 2...Particle refining device, 3.
...Partition wall, 4...Discharge port, 5...
... Furnace slag pot, 6 ... Blower, 7 ... Dust collector, 8 ... Heat exchanger, 9 ... Heat medium conduit, 10 ... ...Cooling gas purge pipe, 11...
...Moving floor, 12...Fixed room, 13...
・・Rotating kiln, 14・・Literary wall, 15・・・・
...Melting furnace slag, 16...Rotating body, 17...
...Rotating axis, 18...Gap, 19...
- Cooling fluid spout, 20... hole.

Claims (1)

[Claims] 1 In a method of recovering the heat possessed by various types of melting furnace slag produced in the iron and steel manufacturing process, a plurality of rotating bodies each having a horizontal axis are arranged in a tower, and adjacent rotating bodies overlap in the vertical direction. As shown in FIG. The cooling fluid is forced to rise inside the tower by circulating a cooling fluid through a circulation route with a cooling fluid that cools the falling melting furnace slag, and the cooling fluid heated to a high temperature by this cooling is cooled. Heat from the melting furnace slag is characterized in that the cooling fluid cooled by the heat removal is fed into the tower through a circulation route after being taken out before or after dustproofing and recovering the heat by heat removal through heat exchange. How to recover.