JPS5993810A - Device for solidifying thin molten slag layer - Google Patents

Abstract

PURPOSE:To provide a titled device for solidifying a thin molten slag layer by a rotary drum system which enables smooth solidification of a thin slag layer on a rotary drum by providing heating elements in the bottom and side wall parts of a slag pool. CONSTITUTION:The molten slag 4 introduced by a slag spout 2 is stored temporarily in the recess formed of two water-cooled rotary drums 6 and the side walls-provided at both ends of the drums 6, whereby a slag pool 16 is formed. A heating element such as a round bar-like carbon electrode 22 is provided along the outside circumference of each drum 6 in the trough part 20 formed by the drums 6 and in the positions where both axial ends of the drum 6 and the side walls 8 contact with each other. The heating element is connected with a power source device 24, and is heated electrically. The temp. of the electrode 22, etc. is maintained at the temp. at which the slag 4 loses its fluidity or above. The sticking of the slag 4 is not observed by the above-mentioned device and there is no slipping phenomenon, whereby the smooth continuation of the operation for depositing the slag on the drums 6 is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a molten slag thin layer solidification device, and more particularly to a solidification device using a rotating drum type to stabilize slag adhesion.

The temperature of molten slag discharged from blast furnaces etc. varies somewhat depending on the initial, middle and final stages of tapping, but it is 1450 to 1
The temperature is in the range of 550°C, and its quantity reaches about 1/3 of the amount of iron tapped, so its sensible heat amount is an art. Therefore, recently,
From the point of view of energy conservation, the technology of explicit recovery from molten slag has become an important issue.

Regarding the method of explicitly recovering molten slag, due to the characteristic that slag has low thermal conductivity, a method is generally adopted in which heat is recovered by making the molten slag finer or thinner to increase its specific surface area. The granulation method is to use high-pressure air or a rotary table.

A method has been proposed in which the molten slag is scattered by flowing down into a rotating drum, and a technique has also been proposed in which heat is recovered through a crushing process after forming the molten slag into a thin plate shape.

As a method for obtaining this thin plate-like solidified slag, US Pat.
There is No. 050884. This method is shown in Figure 1 (5), (B
), two water-cooled rotary drums 6 rotate the molten slag 4 supplied by the slag gutter 2 upward in opposite directions, and a recess formed by side walls 8 provided at both ends of the drums 6, This is a method in which the thin plate-shaped solidified slag 4A adhering to the surface of the drum 60 is scraped off with a scraper 10 by rotating the rotating drum 6.

In addition to the conventional twin-drum method described above,
There is also a one-drum system as shown in the figure. This method involves rotating the molten slag 4 flowing down from the slag gutter 2.
In this method, a thin layer of solidified slag 4A is deposited on the surface of the rotating drum 60 by storing the slag in a recess formed by the drum 6, the side wall 12, and the bottom 14 to form a slag pool 16.

In any of the above methods, the rotary drum 6 is filled with cooling water 1.
Since the molten slag 4 is internally cooled by the rotary drum 6, the temperature of the molten slag 4 in contact with the rotating drum 6 decreases, and is also cooled by the side walls 8, etc., causing a rapid temperature decrease and an increase in viscosity. In particular, in the conventional device shown by Bl, 2
In the V-shaped valley 20 formed by the drums 6, cooling is achieved by both drums 6, and in the conventional apparatus shown in FIG. part 12 and bottom part 141
/1m, sensible heat is absorbed, so the temperature of the molten slag 4 decreases and its viscosity increases. As a result, Figure 1 Prisoner (
In the case of the apparatus shown in B), in the valley part 20 formed by the two drums 6, the two drums 6 rotating in phase draw the molten slag 4 together, forming a fixed slag 4B in the valley part 20, New molten slag 4 no longer adheres to the surface of the rotating drum 60, causing a so-called slip phenomenon. Also, in the case of the apparatus shown in FIG. 2, due to the increase in viscosity due to the temperature drop of the molten slag 4, the fixed slag 4B formed at the bottom of the slag sol 16 and the highly viscous slag 4 to be attached to the surface of the drum 60 are attracted to each other. If the adhesive force to the fixed slag 4B formed on the bottom portion 14 is greater than the adhesive force to the drum 6, no new molten slag 4 will adhere to the surface of the drum 60, and a slip phenomenon will occur.

Such a slip phenomenon often occurs when using a rotating drum system, and once the slip phenomenon occurs, the rotating solid drum comes into contact with the solidified slag, and the slag loses its adhesion to the surface of the drum 6, causing the operation to be interrupted. This becomes an unavoidable situation.

The slipping phenomenon in the rotating drum method is the greatest drawback of the conventional device, and is the biggest reason why the one-bokuto method is not put into practical use.

An object of the present invention is to provide a molten slag thin layer solidification device that eliminates the drawbacks of the conventional rotary drum type device and enables smooth continuous operation.

The gist of the present invention is as follows.

That is, a slag gutter that guides molten slag discharged from a blast furnace, etc., a side wall portion and a bottom portion that store molten slag flowing down from the end of the slag gutter to form a slag pool, and a side wall portion and a bottom portion that are in contact with the molten slag of the slag pool. A molten slag thin layer solidification device comprising a cooling drum that rotates and a stripping device for removing solidified slag adhering to the surface of the cooling drum. This is a molten slag thin layer solidification device characterized by having heating elements provided on both sides.

The inventors have discovered that the cause of the above-mentioned slip phenomenon in the conventional rotary drum system is the valley where two drums rotate in opposite directions in the twin drum system, and the valley where two drums rotate in opposite directions in the twin drum system. In this case, we focused on the fact that this is caused by the solidification of molten slag at the part of the bottom of the slag pool that comes into contact with the rotating drum, and devised a method to prevent the solidification of molten slag by installing a heating element in that part. , has completed the present invention.

The case of the twin-drum system in which the present invention is implemented is shown in the attached FIGS. 3(A), CB) and FIG. 4 will be described. That is, the molten slag 4 introduced by the slag gutter 2 is temporarily stored in the recess formed by the two water-cooled rotating drums 6 that rotate in opposite directions in the upward direction and the side walls 8 provided at both axial ends of the drums 6. slag pool 16
The structure for forming the grooves is the same as that of the conventional device, but in the present invention, there are grooves 20 formed by the two rotating drums 6 and on the outer periphery of the drums 6 at the positions where both axial ends of the drums 6 and the side walls 8 touch. A round bar-shaped carbon electrode 22 was provided along the line, and this was connected to a power supply device 24 to perform electrical heating. The power supply device 24 button is provided with a current control device, and controls the current flowing so that the temperature of the carbon electrode 22f7) is maintained at a temperature of 1000° C. or higher at which the molten slag 4 loses its fluidity.

Since the side wall 8 is usually constructed of an insulating material such as a refractory brick, in this case, the carbon electrode 22 can be buried as is with mortar, etc., but in the case of a conductive material such as a cast iron material, as shown in FIG. It is necessary to protect it with an insulating member 26, and it is also necessary to protect the lower part of the carbon electrode 22 provided in the valley part 20 with an insulating member 26 made of asbestos or the like so that it does not come into direct contact with the rotating drum 6. .

In the pilot test device of the present invention by the inventors,
The carbon electrode 22 is buried in the side wall 8 using alumina-based fireproof castable, and the carbon electrode is installed in the valley part 20 using plate-like asbestos, and the temperature of the carbon electrode is set to 1150-1
When the temperature was controlled at 350° C., no adhesion of the molten slag 4 was observed, and therefore, the operation of smoothly adhering the molten slag to the rotating drum 6 could be continued without occurrence of a slip phenomenon.

In the case of the one-drum system shown in FIG. 2, the slag is placed parallel to the axial direction of the drum 6 at the contact area between the bottom portion 14 and the rotating drum 6, which forms a slag pool 16 to which the molten slag 4 tends to stick. Carbon electrodes 22 are installed along the outer circumference of the drum 6 at both lengthwise ends of the rotating drum 6 in the pool 16.
It has been found that the most effective method is to provide

As is clear from the above examples, the molten slag thin layer solidification device using the σ-n rotating cooling drum system of the present invention has a heating element such as a carbon electrode that can conduct electricity to either or both of the bottom and side walls of the slag pool to be formed. By providing this, the following effects could be achieved.

(b) By heating the molten slag in the slag pool that is formed, it is possible to prevent the generation of stuck slag due to cooling from the side walls, etc., and eradicate the slip phenomenon, so that a thin layer of slag can be deposited on the rotating drum. Solidification could be carried out smoothly.

(b) Stable operation was made possible by (b), and the apparent cost of slag recovery was significantly reduced by increasing the operating rate and reducing repair costs.

(c) A part of the heat generated energy of the heating element can be recovered as slag sensible heat, and the increase in heating costs is more than compensated for by the improvement in operating efficiency and the reduction in repair costs due to (b), resulting in a reduction in overall costs. was able to make a significant contribution to

B) Due to the effects of (a), (b), and ←→, it has become possible to industrialize a method for recovering sensible heat from slag using a rotating cooling drum system, which was considered impossible to industrialize in the past.

In the above embodiments of the present invention, a case has been described in which a carbon electrode is used as the heating element, but it goes without saying that the heating element is not limited to a carbon electrode, and a heating element such as a carboranidum can also be used.

[Brief explanation of drawings]

Figures 1 (A) and (B) show conventional examples of molten slag thin layer solidification equipment using the twin-drum method. 3(A), (B) and 4 are front sectional views showing a conventional example of a thin layer solidification device, and FIG. 4 shows a molten slag thin layer solidification device according to the present invention, and FIG. 3(5) is a front sectional view thereof. Figure 3 (B) is a side sectional view, Figure 4 is Figure 3 (5)
FIG. 2 is an enlarged side sectional view of part A of FIG. 2... Slag gutter, 4... Molten slag 4A.
...Solidified slag, 4B...Fixed slag 6...Water-cooled rotating drum, 8...Side wall 10...Scraper (peeling device) 12...Side wall part, 14...Bottom part 20...
Valley part, 22... Carbon electrode (heating element) 24...
power supply. Representative Patent Attorney (Omitted) Takeo Figure 1 (A) (B) Figure 2

Claims (1)

[Claims] (1) A slag gutter that guides molten slag discharged from a blast furnace, etc., a side wall 7f portion and a bottom portion that store the molten slag flowing down from the end of the slag gutter to form a slag pool, and a molten slag in the slag pool. A molten slag thin layer solidification device comprising a cooling drum that rotates in contact with the cooling drum and a peeling device that removes solidified slag adhering to the surface of the cooling drum, wherein either one of the bottom portion and the side wall portion of the slag pool Or a molten slag thin layer solidification device characterized by having heating elements provided on both sides.