JP2866199B2 - Fluidized bed gas dispersion equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fluidized bed gas dispersion apparatus used in a fluidized bed pre-reduction furnace for iron ore, chromium ore, and the like.

Background Art Iron ores and other metal ore resources tend to decrease in lump and increase in powdery ones. Currently, however, active efforts are being made to concentrate low-grade ores such as flotation or magnetic separation. This trend is expected to increase further in the future, partly due to the progress being made.

Therefore, in recent years, the so-called smelting reduction method for producing molten metal directly from powder ore, that is, after preliminarily reducing powder ore in a fluidized bed prereduction furnace, the obtained prereduced ore powder was filled with a carbonaceous solid reducing agent A means has been developed for introducing into a smelting reduction furnace where it is liquefied while being reduced to form a molten metal.

By the way, in the fluidized bed pre-reduction furnace, when the furnace diameter becomes large, the gas flow in the fluidized bed becomes uneven and it becomes difficult to properly fluidize it. A gas distribution plate provided with a large number of gas distribution holes is provided at the lower part of the furnace, which is a port.

When a high-temperature gas generated in a smelting reduction furnace is used as the fluidized reducing gas, there is a disadvantage that the generated gas contains a large amount of dust, so that the gas dispersion plate is clogged.

To solve this, as shown in FIG.
Japanese Patent Application Laid-Open No. 62-29094 discloses a fluidized bed dispersing device 3 in which a plurality of rods 2 which can be extended in the longitudinal direction are arranged so as to cross up and down inside a pre-reduction furnace 1. In this example, the rod 2 is pulled out occasionally so as to remove the deposits 12 such as dust adhering to the surface of the rod.

This technique has a problem that the rod cannot be pulled out due to thermal deformation of the rod.

In addition, the present applicant has proposed a technique in Japanese Patent Application Laid-Open No. S59-107185, in which the size of the opening is changed by rotating parallel deformed bars.

This technique changes the size of the opening between the rods, and is not a technique for preventing clogging of the rods due to dust.

DISCLOSURE OF THE INVENTION The object of the present invention is to solve the above-mentioned problems, and aims to prevent thermal deformation of the rod and clogging of the dispersion plate by dust, and to extend the life of the rod and stabilize the fluidized bed. It is an object of the present invention to provide a fluidized-bed gas dispersion apparatus capable of performing the above steps.

The present invention provides a grade in which a plurality of rotatable rods having a circular cross section are arranged side by side in a plane, and a plurality of bars arranged in parallel in a direction intersecting with each other in a plurality of stages, and a rotation for rotating each of the rods And a device.

The bar groups vertically adjacent to each other may be arranged so as to be orthogonal or oblique to each other when viewed from above.

It is desirable that the aperture ratio formed by these rod groups is 2 to 10%.

The rotating device has a pinion fixed to each end of the rod,
It can be composed of a rack that engages with a plurality of pinions and a power cylinder that reciprocates the rack.

Other rotating means may include a sprocket fixed to the end of the rod, a chain engaged with the sprocket, and a drive motor for the chain.

The rotating device is preferably a continuous rotating device. In this case, the rotation speed of the rod may be set in the range of 0.1 to 3.0 rpm.

 Further, the rotating device may be an intermittent rotating device.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of a first embodiment of the present invention.
FIG. 1 (a) shows a two-stage dispersion plate, FIG. 1 (b) is a side view of the rod rotation drive mechanism of FIG. 1 (a), and FIG. 2 is a second embodiment of the present invention. FIG. 2 (a) is an explanatory view of FIG.
FIG. 2 (b) is a side view of the rod driving mechanism of FIG. 2 (a), FIG. 3 is a graph showing the operation of the present invention,
FIG. 4 is an explanatory view of a conventional example.

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a rod is rotated, for the following reason.

The load of fine ore is applied to the rod in the cross-sectional direction, and if the temperature distribution differs depending on the location of the rod, the rod will be deformed, or if the rod is rotated, the load and temperature distribution difference will average. The deformation can be prevented.

Dust contained in the introduced reducing gas and particles falling from the fluidized bed adhere to the rod, but when the rod is stationary,
Due to the rising reducing gas, it adheres only to the upper and lower surfaces of the rod and does not adhere to the side surfaces. Therefore, if the rod is rotated, no adhesion of dust or particles occurs.

FIG. 1 is an explanatory view of a first embodiment of the present invention. FIG. 1 (a) shows a movable rod having a two-stage structure in a preliminary reduction furnace 1.
3 shows a dispersion plate 3a made of 2a. FIG. 1 (b) shows a rotary drive mechanism of the rod of FIG. 1 (a).

As shown in FIGS. 1 (a) and 1 (b), both ends of the movable rod 2a are rotatably supported by bearings 6 provided outside the furnace via a gas seal portion 7. The portion is configured such that the left and right racks 4 meshed with the pinion 5 are moved by the cylinder 8 to rotate the movable rods 2a.

FIG. 2 is an explanatory view of a second embodiment of the present invention. FIG. 2 (a) shows a movable rod having three stages in a preliminary reduction furnace 1.
FIG. 2 (b) shows a dispersing plate 3a made of 2a.
Fig. 3 shows a rotary drive mechanism of the rod of Fig. 1 (a).

In this embodiment, an example is shown in which the rotating device includes a chain 9, a sprocket 10, and a motor 11. The rotating device may also be comprised of a belt and a pulley, not shown.

 FIG. 3 is a graph showing the operation of the present invention.

That is, the bar axis indicates the rotation speed of the bar, and the vertical axis indicates the attached matter removal rate. Here, the adhering matter removal rate is the thickness of the adhering matter adhering to the stick in a week when the stick is rotated and operated.
When the operation is performed without rotating the rod at t ₀ mm, and the thickness of the substance adhering to the rod in one week is t ₁ mm, the removal rate is (t ₁ −t ₀ ) / t ₁ × 100%. Say.

FIG. 3 shows an example of the relationship between the rotation speed of the rod and the attached matter removal rate in the continuous operation. When the rotation speed is less than 0.1 rpm, the above-mentioned operation efficiency is not obtained. When the rotation speed is more than 3 rpm, the effect is saturated, and the power cost is merely increased.

Therefore, when rotating the rod continuously,
From 0.1 to 3.0 rpm.

As can be seen from FIG. 3, the rotation speed is preferably 0.1 to 3 rpm.

 Next, the results of the embodiment will be described.

(1) The apparatus of the first embodiment was operated under the following conditions.

Diameter 40mm length 1200mm material resistant alloy rod speed 2.0rpm ambient temperature 980 ° C. ambient gas composition _{H 2 O 20% CO 45%} N 2 34% trace gas 1% reduced ore iron ore rod (5mm or less) As a result, The stick had no deposits, and the life of the stick, which had been only one month in the past, was extended to six months.

(2) The apparatus of the second embodiment was operated under the following conditions.

Rod diameter 30mm Length 1800mm Material Heat resistant alloy Rod rotation speed 1.0rpm Atmospheric temperature 1030 ℃ Atmospheric gas composition H ₂ 17% H ₂ O 0.6% CO 32% CO ₂ 1% N ₂ 49% Trace gas 0.4% Vertical of rod As a result, in the past, it was only one month on average, and in the worst case, in about 6 days, deposits were formed and the opening of the dispersion plate was closed, In the invention, no deposit was formed even after one year of continuous use.

 The present invention has the following excellent effects.

The rod has no deformation and its life has been extended.

The deposits on the rods could be removed and the fluidized bed could be operated stably.

In addition, as a result of various experiments, when rotating intermittently,
It may be every 5 to 10 seconds, and the aperture ratio of the dispersion device refers to the ratio of the projected aperture area of the dispersion device to the total plane area. Usually, it is 2 to 5% in a fluidizing device for fine particles, but a large method is preferable from the viewpoint of preventing clogging. On the other hand, in order to prevent particles from falling downward through the dispersing device, the content is limited to 10% or less.

────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Kazuo Kimura 1 Kawasaki-cho, Chiba-shi, Chiba Kawasaki Steel Corporation Chiba Works (58) Field surveyed (Int. Cl. ⁶ , DB name) F27B 15/10

Claims (8)

(57) [Claims] A plurality of rods having a circular cross section and rotatable in a plane are arranged in a plane, and a plurality of rods arranged in a row are arranged vertically in a direction intersecting with each other, and the rods are rotated. A fluidized bed gas dispersion device comprising a rotating device. 2. A fluidized bed gas dispersion apparatus according to claim 1, wherein vertically adjacent rods are orthogonal or oblique. 3. The fluidized bed gas dispersion apparatus according to claim 1, wherein an aperture ratio is 2 to 10%. 4. A fluidized bed gas dispersion apparatus according to claim 1, wherein the rotating device includes a pinion fixed to an end of the rod, a rack that meshes with the pinion, and a power cylinder that reciprocates the rack. A device consisting of: 5. The fluidized bed gas dispersion apparatus according to claim 1, wherein the rotating device includes a sprocket fixed to an end of the rod, a chain engaged with the sprocket, and a motor for driving the chain. Device consisting of 6. An apparatus according to claim 1, wherein the rotating device is a continuous rotating device. 7. The fluidized bed gas dispersion device according to claim 6, wherein the rotating device controls the rotation speed of the rod to 0.1 to 3 r.p.
m. A fluidized bed gas dispersion device set in the range of m. 8. The fluidized bed gas dispersion device according to claim 1, wherein the rotating device is an intermittent rotating device.