JPH073271Y2 - Fluidized bed furnace - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a fluidized bed furnace that fluidizes granular powder to perform various reactions, heat exchange, and classification or transfer of granular material. .

[Prior Art] When a powder or granular material is put into a container and a fluid such as gas is introduced from the bottom of the container at an appropriate flow rate, the powder or granular material moves with the fluid as if it were boiling. At this time, it is said that the granular material is fluidized, and the layer of the granular material in that state is called a fluidized bed. The fluidized bed is applied in a wide range of fields because the fluidized bed has good contact between the granular material and the fluid, and it is easy to continuously handle the granular material. ing. In addition, even if it is simply called a fluidized bed furnace for reaction, reduction of iron ore, carbonization of coal, cement
Its uses are diverse, such as calcination of lime.

In a fluidized bed furnace, in order to rectify the fluid to be introduced, it is usual to provide a dispersion plate (rectifier) between the wind box (fluid introduction chamber) below the furnace body and the fluidized bed chamber above the furnace body. The distribution plate is provided with fluid passage holes (nozzles) having an appropriate diameter and number (distribution) according to the particle size and amount of the powdery particles, the fluid flow rate, and the like. That is, the powder or granules filled on the dispersion plate are fluidized by the fluid flowing from the air box through the through holes of the dispersion plate to form a fluidized bed.

Conventionally, a furnace body of a fluidized bed furnace is generally configured integrally from a fluidized bed chamber to a wind box, but the following is known as a disposition form of a dispersion plate with respect to the furnace body. In other words, a) Dispersion plate is fixed and deployed integrally with the furnace body: This is the most widely adopted form because it is structurally simple.
Since the dispersion plate is worn due to contact with the powdery particles, a part of the dispersion plate is replaceable and is often attached inside the furnace body.

(B) A plurality of dispersion plates that are supported by inserting the peripheral edges into the recesses in the inner wall of the furnace, and are arranged so that they can be freely inserted and removed through the gaps for inserting and removing the dispersion plates provided on the side wall of the furnace: Since the through holes may be clogged with powder particles in the fluidized bed chamber or dust in the introduced fluid, the dispersion plate should be pulled out to the side of the furnace body through the gap and cleaned, and then re-inserted into the recess. This is the configuration disclosed in Japanese Utility Model Laid-Open No. 62-76896.

[Problems to be Solved by the Invention] The conventional fluidized bed furnaces provided with the dispersion plates as in the above a) and b) have the following disadvantages.

First, in the above item (a), when the fluid passage hole of the dispersion plate is clogged, a person must enter the furnace having a bad working environment to clean or replace the dispersion plate. Further, if the fluidized bed furnace is, for example, a large-scale furnace that is used at a high temperature, it is necessary to cool and raise the temperature for a long time before and after the above work, so that the operating efficiency of the furnace is extremely reduced.

On the other hand, in the case of (b) (No. 62-76896), there is a gap for inserting and removing the dispersion plate on the side wall of the furnace, and it is also possible to insert the dispersion plate between the recess on the inner wall of the furnace and the periphery of the dispersion plate. Since there is a gap, the introduced fluid may leak into the fluidized bed chamber through this gap, and proper fluidization may not be maintained. Further, in many cases, powder particles are caught in these gaps, so that the dispersion plate cannot be smoothly inserted and removed. In particular, since powder particles are deposited in the recesses when the dispersion plate is extracted,
Re-insertion of the dispersion plate requires considerable special measures. Furthermore, structurally the dispersion plate is limited to a flat plate, and this form is used for a dispersion plate with an upward or downward convex portion near the center and a dispersion plate with a discharge pipe for powder particles connected below. Cannot be used.

An object of the present invention is to provide a fluidized bed furnace in which the dispersion plate can be cleaned and replaced relatively easily, and the fluidization of the granular material is not disturbed during the operation.

[Means for Solving the Problems] In a fluidized bed furnace of the present invention, a fluidized bed chamber and a dispersion plate, and a dispersion plate and a wind box are separably joined to each other vertically and separated from the fluidized bed chamber and the wind box. The traverse means for moving the dispersion plate horizontally is provided outside the dispersion plate.

[Operation] Since the fluidized bed furnace of the present invention joins the fluidized bed chamber and the dispersion plate, and the dispersion plate and the air box, respectively, the fluid introduced from the air box leaks into the fluidized bed chamber from the periphery of the air dispersion plate during operation. And there is always proper fluidization.

When the operation of the furnace is stopped, the dispersion plate can be separated from the fluidized bed chamber and the wind box by unraveling each of the above-mentioned joints, and can be horizontally moved to the side of the furnace body by the traverse means. Maintenance work such as can be done easily. For example, even if the furnace is a large-scale furnace used at high temperature, if only the dispersion plate is separated and moved as described above, the dispersion plate will be cooled rapidly and will be outside the furnace in a short time. The work can be started in a much better environment than in a furnace. Regarding the joining of the dispersion plate with the fluidized bed chamber and the air box, it is not necessary to provide a recess or gap in which powder particles will accumulate during operation. It is not hindered by such things.

Further, in the fluidized bed furnace of the present invention, there are almost no restrictions on the shape of the dispersion plate. For example, if the dispersion plate has a convex portion on the top or bottom, the fluidized bed chamber or the air box should be separable from the dispersion plate at a height higher than the height of the convex portion. This is because when the pipes are connected, the discharge pipe can be separated from the dispersion plate together with the wind box (see the first embodiment described later).

[Embodiment] FIG. 1 is a vertical sectional view of a fluidized bed furnace according to a first embodiment of the present invention. This fluidized bed furnace 1 is used for preliminary reduction of iron ore in the smelting reduction iron manufacturing method (preliminary reduction furnace), and the iron ore (powder ore) is charged in the fluidized bed chamber 10 as powder and granules to perform smelting reduction. The gas generated from the furnace (not shown) is introduced into the gas inlet 31 of the wind box 30.
Introduce more. Since the gas generated in the smelting reduction furnace contains reducing components such as CO and H ₂ and has a high temperature of several thousand hundreds of degrees Celsius, this gas reduces iron ore while fluidizing it and converts it into pre-reduced iron. The pre-reduced iron ore is discharged from the discharge pipe 32 of the fluidized bed furnace 1.
After being discharged from the furnace, it is charged into the smelting reduction furnace and melted and finally reduced.

The main body of the fluidized bed furnace 1 is a vertically long container-like structure in which a refractory is stretched on the inside of a steel shell, and a steel frame (not shown) for vertically arranging the main body is provided around the structure. Only supports 51, 52, 53 that are part of the frame are shown). The fluidized bed furnace 1 is supported by the frame by fixing a bracket 11 protruding outward from the fluidized bed chamber 10 onto a support 51 as shown in the figure.

Between the fluidized bed chamber 10 and the wind box 30 of this fluidized bed furnace 1, there is a dispersion plate.
20 are arranged. The dispersion plate 20 moves from the wind box 30 to the fluidized bed chamber.
A large number of through holes 21 are provided for rectifying the gas introduced into 10. In this embodiment, the upper surface is inclined like a funnel, the discharge port 22 for the pre-reduced iron is provided in the central part, and the discharge pipe 32 is connected to the lower part of the discharge port 22. The upper surface of the dispersion plate 20 was formed into a funnel shape and the discharge port 22 was provided in the central portion of the dispersion plate 20 because coarse iron ore that does not fluidize was deposited on this surface and moved slowly while contacting with the introduced gas. This is because it is discharged from the discharge port 22. As a result, a relatively fine powder of iron ore forms a fluidized bed 10a in the fluidized bed chamber 10, and a relatively coarse powder forms a moving bed (or spouted bed) 10b on the dispersion plate 20. Since each is preliminarily reduced, the fluidized bed furnace 1 can simultaneously process iron ore having a wide range of particle size distribution. The discharge pipe 32 has a lower end fixed to the bottom of the wind box 30, and a blanket-like elastic fireproof packing 23 attached to the upper end fitted into the dispersion plate 20.

The main features of the fluidized bed furnace 1 are: a) fluidized bed chamber 10 and dispersion plate 2
0, and that the dispersion plate 20 and the wind box 30 are separably connected to each other, b) When the above connection is released, the dispersion plate 20 and the wind box 30 are separated.
Are mounted on the supports 52 and 53 of the steel frame, respectively, and in particular, the traverse means 40 that can move the dispersion plate 20 horizontally is provided between the dispersion plate 20 and the support 52 that receives the dispersion plate 20. . Each of these points will be described below.

Regarding the above-mentioned a), first, on the upper surface of the outer peripheral portion of the dispersion plate 20, the fluidized-bed chamber 10 and the iron shell and the refractory of the dispersion plate 20 are vertically divided to form a separable joint surface 41. This interface 41
Flange on the lower end of the fluidized bed chamber 10 so that
A flange 24 is provided on the outer peripheral portion of the upper end of the dispersion plate 20, and both are fastened with bolts 25a and nuts 25b during operation of the fluidized bed furnace 1. Similar joint surface between dispersion plate 20 and wind box 30
42 is formed, and the lower end flange 27 of the dispersion plate 20 and the upper end flange 33 of the wind box 30 are fastened with bolts 34a and nuts 34b.

The traversing means 40 of the above b) is constructed by mounting the wheels 26 below the upper end flange 24 of the dispersion plate 20 and laying the rails 43 on the support 52. The rails 43 are arranged in parallel with each other so that the two rails shown in the drawing are arranged in parallel from a side of the fluidized bed furnace 1 to a maintenance deck (not shown) located at a position completely separated therefrom.
4 were arranged on the left and right sides and the front and rear sides (direction perpendicular to the paper surface) of the figure. A drive source (motor or the like) may be connected to the wheels 26, but no drive source is provided for the wheels 26 of this embodiment, and the dispersion plate 20 is pulled back and forth by another pulling source (not shown). I decided to do it.

By the way, since the fluidized bed furnace 1 is a preliminary reduction furnace for iron ore as described above, deposits are often generated in the through holes 21 of the dispersion plate 20. Granules (iron ore) in fluidized bed 10a or moving bed 10b
May be caught in the through hole 21 like other powders, but in the case of iron ore, at high temperature (the temperature of the introduced gas is set high to promote the reduction reaction). One of the reasons is that the adhesion becomes strong by welding. Further, since the gas generated from the smelting reduction furnace is introduced, dust such as iron powder contained in the gas or pressure loss (temperature drop) while passing through the through hole 21 even though it was dissolved in the gas at high temperature. This is also because oxides and the like precipitated by the above are likely to adhere to the through holes 21. The dispersion plate 20 is a consumable item that gradually wears due to contact with iron ore, and requires periodic replacement.

Due to these circumstances, the dispersion plate 20 needs to be inspected frequently and regularly cleaned and replaced. However, the fluidized bed furnace 1 having the above-mentioned configuration has a dispersion plate 20 when the operation is stopped. 20 maintenance can be done easily. This separates the dispersion plate 20 from the fluidized bed chamber 10 and the wind box 30,
This is because the fluidized bed furnace 1 can be repaired after moving to the side (front and rear in the figure), and the procedure for this is as follows.

From the state shown in the figure, the bolt 25a and the nut 25b are removed to separate the joint surface 41. Wheels 26 and rails 43 in traversing means 40
And the distance S1 between the lower end surface of the flange 33 of the wind box 30 and the support
Since it is smaller than the distance S2 from 53, the dispersion plate 20 and the wind box 30 are placed on the support 52 via the traverse means 40 by this operation.

Remove the bolt 34a and nut 34b to separate the joint surface 42,
Place the wind box 30 on the support 53. And through
The gas inlet 31 and the exhaust pipe 32 are lowered by a height equal to the interval S2 together with the wind box 30, but the exhaust pipe 32 is a telescopic pipe.
Since it is connected to the fixed discharge pipe 55 via 54 and a flexible joint (not shown) is also provided at the upstream portion of the inlet 31, the wind box 30 can be smoothly lowered. The upper end of the discharge pipe 32 is
By this operation, it is extracted from the dispersion plate 20.

The dispersion plate 20 in a state of being separated from the fluidized bed chamber 10 and the wind box 30 and mounted on the support 52 via the traversing means 40 is traversed by using the above-mentioned traction source and moved to the above maintenance deck.

Wait for the dispersion plate 20 to cool, and then perform appropriate maintenance such as cleaning the through holes 21. When the wear is significant, it is necessary to replace the dispersion plate 20, but since the dispersion plate 20 of this embodiment is formed by a combination of inner and outer refractories fitted at the dotted line 20a in the figure. It is possible to easily replace only the refractory material inside, which is a consumable part.

The dispersion plate 20 that has been maintained, the traction source and the traverse means
40 is made to traverse between the original fluidized bed chamber 10 and the wind box 30, and the joint surfaces 42 and 41 are closed. Bolt 25a
And 34a are made sufficiently long so that the nuts 25b and 34b can be engaged with each other from the state where the joint surfaces 41 and 42 are open (the above state), the nuts 25b and 34b can be screwed.
Since it is possible to pull up the dispersion plate 20 and the wind box 30 by tightening, the means for jacking up is unnecessary. When the above operation is completed, the next operation can be started.

Next, a second embodiment of this invention will be described with reference to FIG. The fluidized bed furnace 2 shown in this figure is also a preliminary reduction furnace for iron ore, and the type of powder or granular material (iron ore) and the introduced fluid (gas generated in the smelting reduction furnace) are the same as those in the first embodiment. However, it is a type of furnace that is not supported by a steel frame and stands on the ground.

This fluidized bed furnace 2 also has a dispersion plate between the fluidized bed chamber 60 and the wind box 80.
Equipped with 70. Although it has the same number of through holes (not shown) for rectifying the introduced gas, this dispersion plate
Unlike the above-mentioned embodiment, the reference numeral 70 is flat and does not include a preliminary reduced iron discharge port or discharge pipe. In this fluidized bed furnace 2, iron ore is charged after the grain size is adjusted, and almost all of the iron ore is fluidized and preliminarily reduced. Therefore, the preliminary reduced iron discharge pipe 65 is downward from the lower side wall of the fluidized bed chamber 60. Is arranged toward. In the figure, 67 is a fixed discharge pipe following the discharge pipe 65, 66 is a connecting flange of these discharge pipes 65 and 67, and 81 is a wind box.
80 gas inlet pipe, 62 exhaust gas pipe from the fluidized bed chamber 60, 64
Is a fixed exhaust gas pipe that follows, 63 is these exhaust gas pipes 62, 64
It is a connecting flange.

Also in the fluidized bed furnace 2, a) the fluidized bed chamber 60 and the dispersion plate 70, and the dispersion plate 70 and the wind box 80 are detachably connected at the joint surfaces 91 and 92, respectively, and b) the wheels are attached to the dispersion plate 70. 72
The provision of the traversing means 90 including the rail 93 and the rail 93 is a major feature, but these are slightly different from the fluidized bed furnace 1 of the first embodiment in the following points.

That is, brackets 61 and 71 are provided on the respective side walls of the fluidized bed chamber 60 and the dispersion plate 70, and hydraulic jacks 101 and 102 having expansion and contraction ends arranged immediately below these are fixed to the ground, respectively.
The above-mentioned traversing means 90 is provided between the jack 102 and the bracket 71.
Is provided. The rail 93 of the traversing means 90 extends to a maintenance deck (not shown) apart from the fluidized bed furnace 2, and the above jacks 102 are provided in a plurality of rows below the maintenance deck (not shown).

Therefore, if the jacks 101 and 102 are extended after the joint surfaces 91 and 92 and the joint flanges 63 and 66 are jointed (both joints using bolts), the fluidized bed will not flow to the wind box 80 fixed on the ground. The chamber 60 and the dispersion plate 70 can be separated upwards. Since the expansion and contraction stroke of the jack 101 is longer than that of the jack 102, the fluidized bed chamber 60 and the dispersion plate 70 are also separated. At this time, the dispersion plate 70 is mounted on the rails 93 on the jack 102 via the wheels 72 provided downward on the bracket 71, so that the fluidized bed furnace 2 is traversed by front and rear (direction perpendicular to the plane of the drawing). Then, for example, move to the maintenance deck.

Since the dispersion plate 70 can be separated and traversed in this way,
Also in this fluidized bed furnace 2, maintenance work such as inspection, cleaning or replacement of the dispersion plate 70 can be easily performed.

Although two embodiments have been introduced above, the present invention can be implemented as follows.

B) As traversing means, in addition to the wheels and rails mentioned in the examples, those that use rollers and linear motion bearings in combination with other types of raceways, or those that use sliding surfaces are provided. Good. A drive source such as a motor may be connected to the wheels and rollers.

B) Unlike the embodiment, the structure may be such that the dispersion plate is always held at a constant height via the traversing means, while the fluidized bed chamber can be separated upward and the air box can be separated downward.

C) If two dispersion plates are prepared and used alternately, one can be separated from the fluidized-bed furnace and traversed for maintenance, while the other can be joined to the furnace for operation, thus improving operating efficiency.

D) For a small fluidized bed furnace, for example, it may not be necessary to separate the dispersion plate and the wind box. This is because it is possible to perform the minimum necessary cleaning on the dispersion plate even when the dispersion plate and the wind box are integrated and separated from the fluidized bed chamber and traversed laterally.

E) The invention is not limited to the iron ore reduction furnace described in the examples, and the present invention can be carried out in various fluidized bed furnaces such as a lime dry distillation furnace, a cement or lime calcination furnace that require inspection and maintenance of dispersion plates. In addition to the reactor, heat exchange, classification of powder and granules,
It can be applied to various fluidized bed furnaces used for transfer.

[Effects of the Invention] According to the fluidized bed furnace of the present invention, it is easy to inspect, maintain, and replace the dispersion plate, and the fluidization of powder particles during operation is not disturbed. In addition, various shapes of dispersion plates can be used, and the exhausted dispersion plates can be used as a whole (from the part with the through hole to the peripheral wall part such as the iron skin).
It also has the advantage of being easy to replace.

[Brief description of drawings]

1 and 2 are all related to a fluidized bed furnace for preliminary reduction of iron ore, which is an embodiment of the present invention.
FIG. 2 is a side sectional view of the second embodiment, and FIG. 2 is a longitudinal sectional view of a main part of the furnace of the embodiment. 1,2 ...... Fluidized bed furnace, 10,60 ...... Fluidized bed chamber, 20,70 …… Dispersion plate, 30,80 …… Wind box, 40,90 …… Transverse means, 41,42,91,92
…… Joint surface.

Claims (1)

[Scope of utility model registration request] 1. A fluidized bed furnace comprising a fluidized plate having fluid passages between a fluidized bed chamber in the upper part of a furnace and a windbox in the lower part of the furnace. And a traverse means for horizontally moving the dispersion plate separated from the fluidized bed chamber and the wind box, are provided outside the dispersion plate.