DE2165010A1 - Method of removing broken small particles from a fluidized bed - Google Patents

Description

Dr. F. Zumstöln sen. - Dr. L Assmann Dr. R. Koenlgsberger - Dlpl.-Phys. R. Hölzbauer - Dr. F. Zumsteln Jun.

PATENT LAWYERS

TELEPHONE: COLLECTIVE NO. 2253.41

TELEX 52997Θ

TELEGRAMS: ZUMPAT CHECK ACCOUNT: MUNICH 91139

BANK ACCOUNT: BANKHAUS H. AUFHÄUSER

8 'MUNICH 2,

BRÄUHAUSSTRASSE 4 / III

5 M
P-2226-52

ITIPPOH "KOKAU KABUSHIKI KAISHA, Tokyo

and
Daizo KUHII, Tokyo, Japan

Procedure for removing broken small particles

from a fluid bed. ■

The invention "relates to a method of removing broken Particles from a fluidized bed, and in particular to eliminate an adverse effect of these particles for the fluidized bed process by accumulating the particles on top of the fluidized bed and by fusing and sintering of the particles.

209828/0737

In recent years, numerous studies have been carried out on "direct reduction methods for iron ores, and the majority of these studies have resulted in practical evaluation. For example, the Fu-iron method, the H-iron method, the ADI- method, the Fior process which Stelling method, the bubble cooker method and the ITovalfer-Onia method as I ¹ Iiess "bed method under the direct reduction process" known. the common characteristic of the above fluidized bed process is that a gaseous reducing agent in On the other hand, a new fluidized bed method using composite pellet masses of fine iron and some kind of reducing agent has been introduced. In any case, the following disadvantages are inevitable in performing the fluidized bed method by abrasion of the green, pelletför moderate masses generated in the fluidized bed. However, this ore powder can easily be removed upwards with the Meissen airflow. On the other hand, these green, pellet-shaped masses are often broken into smaller pieces by thermal or mechanical shock loads during fluidization. These broken small pieces can hardly be removed and therefore easily accumulate on the top of the fluidized bed. It is obvious that these accumulated masses are fusible and sinterable. Once these masses are sintered, they naturally exert an unfavorable influence on the fluidized bed process. ”An effective countermeasure to prevent these phenomena from occurring has not yet been found

The invention is directed to the broken, small bulk particles that accumulate on top of the fluidized bed have to be removed before the masses are melted and sintered. The features of the invention lie in a development far away from the broken, small mass parts that are on the Top of the fluidized bed, through an overflow pipe, that is located near the top of the fluidized bed

209828/0737

The inventive method should act so that a stable Operation can be continued ".

The following are, for example, preferred embodiments the invention explained in more detail with reference to the accompanying drawing. . .

Fig. 1 shows a representation for ^; Explanation of the method according to the invention; ■

Fig. 2 shows a modified embodiment of the invention manure;

Pig. 3 shows a further modification of the Maafferr method according to the invention; .

Pig. FIG. 4 shows another modified embodiment of FIG Invention.

rf _.

The broken, kleinßn mass particles caused by thermal and mechanical shock see ¹ influences during the fluidization. The resulting, broken, small particles can hardly be carried upwards with the hot air flow and therefore remain on the top of the fluidized bed. Once these masses have accumulated on the top, they fuse and sinter. This reduces the amount of defect-free masses, and various unfavorable influences on the implementation of the method are the result. Similar difficulties arise when these masses reach the next bed. These phenomena can be avoided by an overflow pipe located near the top of the fluidized bed, as shown in the accompanying drawing.

Based on Pig. 1 are the principles of the invention Procedure understandable. The reference numeral 1 refers to a treatment vessel similar to that of a conventional one Fluid bed process corresponds. In this cauldron or container

209828/0737

"is a fluidized bed 12, a throttle area 2, a transferred Bed 3, a cooling bed and a stairway area 4, the are arranged in the same way as in known gate directions. The reference number 5 relates to an input hopper for green, pellet-shaped hats, and 6 denotes a conveyor. More, additional facilities that with regard to -. to the method according to the invention of a known device are added, v / earth through the overflow pipe 1, a control valve 8 and a suitable receptacle 9 is formed. Now when the operation of the device begins, it becomes an upward one Hot air flow is blown in from the lower region of the boiler in a manner not shown, known per se. An ore powder, which is formed by abrasion of the fluidizing, green masses, is drawn in with the hot air stream as shown Kfeil taken while at the same time during the ■ -Fluidiöierung small mass particles broken by thermal and mechanical impacts are separated and build up on the top of the bed. In this case, the overflow pipe causes the severed hatches to be removed and can be passed continuously through this pipe.

FIG. 2 is a modified example according to FIG. 1. In the device of FIG. 2, there is an opening and closing device ~ 'TO added to the device of FIG. This facility enables the masses in question to be removed if necessary, FIG. 3 shows a further modification. According to FIG. 2 the tube passes through the fluidized bed and opens near the surface of the fluidized bed. Fig. 4 shows again a variation. Here the pipe is arranged along the center line of the boiler. The inlet of the tube is open, as at the previous examples.

The method according to the invention has numerous advantages achieved. The greatest advantage is that the operating conditions of the fluidized bed process are free as required

2Ö9S28 / 0737

Can be changed by, for example, the fluidized bed temperature increased, the green, pelletförtnien masses changed, the amount of fluidizing gas can be reduced, etc. This was up to not possible in practice because the broken, small ones Parts of the pellet-shaped masses melted or sintered. The inventive method, the thermal and production efficiency of the known fluidized bed process can be increased to the highest degree.

209828/0737

Claims (5)

Patent claims: 1. Fluidized bed process for ore powder, characterized in that that the broken, little hate parts. that accumulated on the top of the fluidized bed and which are caused by thermal and mechanical impacts during fluidization, be directed through an overflow pipe near the top of the fluidized bed. 2. The method according to claim 1, characterized in that the inlet of the overflow pipe on the side of the treatment vessel lies. 3. The method according to claim 1, characterized in that the overflow pipe runs through the side of the treatment vessel. 4. The method according to claim 1, characterized in that the Overflow pipe along the center line of the treatment vessel is introduced. 5. The method according to any one of claims 2 to 4, characterized in that that the inlet of the overflow pipe can be closed and opened. 2Q9828 / Ö7S7 ^8e