JP2862863B2 - Multi-chamber split type fluidized bed furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluidized-bed furnace for treating a granular material in a fluidized state.

[0002]

2. Description of the Related Art A powdery or granular material is put into a container having a perforated plate or a diffuser tube, and gas is caused to flow through the perforated plate or a diffuser tube. When the upward force acting on the granular material corresponding to the speed is balanced with the gravity of the granular material, the granular material exhibits a so-called flowing state. In this fluidized bed, the granules are actively moving by the rising airflow, and the temperature of the whole bed can be kept almost constant,
Because of its easy control, fluidized bed furnaces are widely used in various industrial fields. For example, in recent years, a fluidized bed manufacturing process has been used to manufacture eye anchor hydride, which has been attracting attention as a raw material for iron and steelmaking, in which iron ore is powdered, charged into a fluidized bed furnace, and reduced gas (hydrogen Gas) and carbonized gas (such as methane gas)
The iron oxide in the iron ore is reduced and carbonized by reacting it with a mixed gas of at a predetermined temperature to produce an anchor carbide.

A technique of this kind is disclosed in Japanese Patent Laid-Open Publication No. 1-1760.
No. 03 discloses, as shown in FIG.
The inside of a fluidized bed furnace 23 having an outlet 1 and an outlet 22 is vertically partitioned by a fluidizing plate 24, a gas injection chamber 25 is provided below the fluidizing plate 24, and a fluidizing chamber 26 above the fluidizing plate 24 is partitioned. Divided into a plurality by the plate 27 (26a to 26e), a gap (communication port) is provided between the partition plate 27 and the fluidizing plate 24,
A fluidized-bed powder processing apparatus, characterized in that the raw material charged into the fluidized-bed furnace 23 through this communication port flows in a flowing state from the input port 21 to the discharge port 22.

However, in the fluidized-bed furnace shown in FIG. 25, since the transfer from the division chamber to the division chamber is performed by a communication port provided at the lower part of the partition plate 27, which is a mere hole, the pressure of the adjacent division chamber is reduced. Back mixing depending on the balance (a phenomenon in which the raw material in the downstream division chamber moves backward to the upstream division chamber)
May occur, thereby reducing the effect of dividing the fluidized bed. Therefore, in order to facilitate understanding of the present invention, back mixing and related problems of a conventional fluidized bed furnace will be described in detail.

In general, in a fluidized bed furnace, powder ore as a raw material is fired or reacted. For this purpose, it is preferable to increase the time during which the ore stays in the furnace. In order to extend the residence time, the diameter of the furnace or the height of the ore layer retained in the furnace may be increased, but the former method increases the equipment cost significantly, and the latter method increases the furnace size. Instead, the power of the gas supply compressor is greatly increased, and the operating cost is increased.

Therefore, a fluidized-bed furnace in which various known gas dispersers and partition plates are combined has been devised. For example, in the case of the dispersion plate method, as shown in FIG. 1, a wind box 1 is provided at the bottom, and gas is supplied from a large number of gas blowing nozzles 3 provided in a gas distributor 2 (dispersion plate) above the wind box 1. The fluidized bed 4 is ejected to form a fluidized bed 4 of the granular material on the gas disperser 2.
Is divided into a plurality (4a, 4b, 4c) by a partition plate 5 in a multi-chamber split type fluidized bed furnace. When the fluidized bed is divided into multiple chambers (when the number n of divided fluidized beds is increased), the ore residence time in the furnace is greatly increased as shown in FIG. In FIG. 2, n = 1 indicates the case where the fluidized bed was not divided.

[0007] In particular, in the case of a plant requiring a residence time of several hours or more, such as an eye anchor hydride production plant, it is inevitable to divide the fluidized bed into multiple chambers (for example, four or seven). . By the way, in order to realize a multi-chamber fluidized bed having such features, it is essential to satisfy the following two points.

That is, back mixing does not occur. That is, as shown in FIG. 3, it is necessary that most of the ore flows from the upstream divided chamber 7 partitioned by the partition plate 6 to the downstream divided chamber 8 via the communication port 9. It is. Conversely, when a phenomenon (back mixing) that flows from the downstream division chamber 8 to the upstream division chamber 7 occurs, the effect of dividing the fluidized bed is reduced. For example, even in the case of four divisions, if back mixing occurs, the ore residence time distribution curve of the ore shown in FIG. 2 is not the same as that of n = 4 as shown in FIG. The curve may have a distribution close to 2.

In order to make the difference in height of the fluidized bed between the upstream divided chamber and the downstream divided chamber appropriate, in order to flow from the upstream side to the downstream side, the fluidized bed height of the upstream divided chamber is set to the downstream side. It must be greater than the height of the fluidized bed in the compartment, but the difference is preferably smaller. For example, in the case of a 7-segmented chamber type fluidized bed furnace, if the fluidized bed height difference is 20
If it is 0 mm, it is 1200 mm (200 mm
× 6), and the average fluidized bed height is 100
It cannot be applied to 0 mm or 2000 mm process (when applied, extra care is required; that is, the furnace height needs to be increased, and the feed gas pressure needs to be adjusted to the highest fluidized bed height). As a result, the cost of both equipment and operation is increased, and the distribution of gas between the divided chambers becomes difficult, that is, if the pressure loss at the nozzle for ejecting the gas is not properly adjusted, the gas may be lost. Will not be evenly distributed).

One of the conventional methods for preventing backmixing of a multi-chamber split type fluidized bed furnace based on the above concept is to reduce the diameter of a communication port for connecting the divided chambers with each other. Is smaller, the difference between the heights of the fluidized beds in the front and rear divided chambers becomes large, and the above-described inconvenience occurs.

Further, the disadvantages of the conventional fluidized bed furnace will be described. When the length of the communication port is 100 mm or less, back mixing occurs. Generally, the pressure at each point in the fluidized bed fluctuates in a time cycle shorter than 1 second, and the ore moves due to the pressure difference between the communication port and the entrance. For example, as shown in FIG. 5, the flow rate of the ore passing through the communication port fluctuates. In FIG. 5, the symbol “+” indicates a flow from upstream to downstream, and the symbol “−” indicates a flow from downstream to upstream (back mixing). Therefore, if the length of the contact is short (for example, 5 m
m), backmixing easily occurs.

However, in this case, if the length of the communication port is long, even if a flow in the “−” direction occurs, the ore in the flow in the “−” direction remains in the communication port, and as a result, The flow is in the “+” direction.

When there is no dense downflow of ore near the entrance and the exit of the communication port, a difference in height of the fluidized bed between the front and rear divided chambers becomes large, and back mixing occurs. If there is no dense downflow of ore near the entrance and the exit of the communication port, a large amount of gas passes through a gap in the communication port.
This leads to a large fluidized bed height difference. In addition, the gas flows between the upstream side and the downstream side, thereby causing back mixing.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object the purpose of preventing the back mixing from occurring and ensuring that the fluidized bed height difference between the front and rear divided chambers is appropriate. It is to provide a fluidized bed furnace which is of size.

[0015]

In order to achieve the above-mentioned object, the present invention provides a method for controlling the height of a communication port in a vertical direction to be equal to or less than a predetermined value, and for setting the length of the communication port communicating between divided chambers to be equal to or more than a predetermined value. The distance between the inlet / outlet of the communication port and the end face of the gas outlet nozzle should be equal to or greater than a certain value. By making the angle of repose larger than the angle of repose, the raw material in the upstream division chamber moves to the downstream division chamber through the communication port without stagnation near the entrance and exit of the communication port and without back mixing. Becomes possible.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The gist of the present invention resides in that a powdered raw material charged from one side is blown from a number of gas blowout nozzles provided in a gas disperser provided in a lower part of a furnace. A bubbling fluidized bed furnace that performs a reaction while fluidizing and discharges the product from the other side,
The fluidized bed is divided into a plurality of division chambers by a partition plate, and a communication port for moving the raw material from the upstream division chamber to the downstream division chamber is provided at a lower portion of the partition plate, and an average of the raw material passing through the communication port is provided. A fluidized bed furnace having a moving speed of 500 mm / sec or less is characterized by satisfying the following conditions. The vertical position of the communication port is 1/4 or less of the height of the fluidized bed,
When the length of the communication port is 100 mm or more, and the blowing direction of the gas blowing nozzle is almost vertically upward, the distance between the communication port inlet and the upstream nozzle end face is larger than 150 mm, and the communication port outlet and the downstream nozzle end face. Is 50mm
When the blowing direction of the gas blowing nozzle is substantially horizontal, the distance between the communication port inlet and the upstream nozzle end face is larger than 200 mm, and the distance between the communication port outlet and the downstream nozzle end face is larger than 100 mm. When the blowing direction of the nozzle is obliquely downward, the distance between the communication port inlet and the upstream nozzle end face is larger than 200 mm, the distance between the communication port outlet and the downstream nozzle end face is larger than 100 mm,
In any of the openings on the upstream side and the downstream side of the communication port, the angle formed by the line connecting the corner of the upper surface of the communication port and the gas outlet with respect to the horizontal plane is larger than the angle of repose of the granular material. I have.

The reasons for limiting the components of the fluidized bed furnace configured as described above will be described in detail below in relation to the operation of the present invention. (1) Prevent only gas from flowing through the communication port. When the gas flows through the communication port, the pressure loss increases, so that the difference between the heights of the fluidized beds in the front and rear division chambers increases (for the same flow rate of the granular material), and back mixing occurs. In order to prevent this, it is necessary that the granular material is filled in the communication port. That is, if only the granular material exists in the communication port, the pressure difference between the upstream fluidized bed and the downstream fluidized bed causes
Move so that the whole granular material is extruded from the upstream side to the downstream side (temporarily or momentarily, even if it moves slightly from the downstream side to the upstream side, if the moving distance is smaller than the length of the communication port, No problem).

Therefore, in order to prevent the gas flow in the communication port, it is preferable to employ the following means. The vertical position of the communication port shall be 1/4 or less of the height of the fluidized bed. It is not preferable that the vertical position of the communication port is too high. This is because the density of the granular material in the fluidized bed is thin at the upper part, and when the position of the communication port is high, the gas easily flows into the communication port. Therefore, the vertical position of the communication port is preferably not more than 1/4 of the height of the fluidized bed.

Forming a dense downward flow of the granular material near the entrance of the communication port. As shown in FIG. 6, when the position of the gas blowing nozzle 11 provided on the dispersion plate 10 is separated from the partition plate 6 by an appropriate distance, the granular material moves as shown by the arrow in FIG. Produces a dense downward flow. Gas is prevented from flowing into the communication port by being blocked by the dense downward flow near the communication port entrance.

The thickness of the dense downward flow of the granular material near the entrance of the communication port is increased. When the granular material moves from the upstream side to the downstream side via the inside of the communication port, a part of the downward flow of the granular material flows into the communication port 9 as shown in FIG. At this time, if the thickness of the descending flow is small, as shown in FIG.
A large amount will be sucked inside. When a large amount of gas is sucked into the communication port, the above-described problem occurs. Therefore, the thickness of the dense downward flow of the granular material near the entrance of the communication port must be large.

As described above, as a result of conducting an experiment on a factor that forms a dense downward flow of the granular material near the entrance of the communication port and increases the thickness of the downward flow, as shown in FIG. It turned out that the relative position of 9 and the gas blowing nozzles (11a, 11b, 11c) was important. In other words, if the gas blowing nozzle is too close to the communication port 9, the thickness of the downflow of the granular material is very small (or no downflow is formed), and a gas flow occurs in the communication port. It was found that the granules could not move in the mouth. On the other hand, it was found that the farther the position of the gas blowing nozzle is from the communication port 9, the greater the thickness of the descending flow near the communication port entrance.

That is, as shown in FIG. 9A, in the case of the upward nozzle 11a in which the gas blowing direction is substantially vertical upward, the inlet of the communication port 9 and the end face of the upward nozzle 11a shown in FIG. Is preferably larger than 150 mm. Also, as shown in FIG.
Horizontally oriented nozzle 1 whose gas blowing direction is almost horizontal
1b (the flow velocity in the nozzle is 10 to 80 m /
Second), it is preferable that the distance X between the entrance of the communication port 9 and the end face of the horizontal nozzle 11b shown in FIG. In addition, as shown in FIG. 9C, in the case of the obliquely downward nozzle 11c in which the gas blowing direction is obliquely downward (the flow velocity in the nozzle is 10 to 80 m / sec), FIG.
(C) The entrance of the communication port 9 and the obliquely downward nozzle 11c
Is preferably larger than 200 mm.

However, the above limitation of the distance X is applied when the average moving speed of the granular material in the communication port is 500 mm / sec or less. That is, when the average moving speed of the granular material is higher than this, the granular material goes from the entrance to the exit of the communication port without causing back mixing at all, without limiting the distance X to a certain value or more. Because they move.
Note that the average moving speed of the granular material refers to the input amount A of the granular material.
Numerical value obtained by dividing the flow rate Q (m ³ / H) obtained by dividing (T / H) by its bulk specific gravity γ (T / m ³ ) by the sectional area (m ² ) of the communication port ( m / H)
Say.

Forming a dense downward flow of the granular material also near the outlet of the communication port. If a dense downward flow of the granular material is not formed near the outlet of the communication port, as shown in FIG.
The effective length of the communication port which is filled with the granular material without the granular material at the outlet portion in the inside is shortened. Then, as described above, back mixing is likely to occur. Therefore, it is preferable to form a dense descending flow near the outlet of the communication port as well as at the inlet. For this purpose, as in the case of the inlet, the distance X between the end face of the gas blowing nozzle and the outlet of the communication port is set to a certain value or more. On the outlet side, it is only necessary to press the granular material in the communication port so as not to slip off, and the thickness of the downward flow may be smaller than that on the inlet side. Specifically, it is as follows.

As shown in FIG. 9A, in the case of an upward nozzle 11a in which the gas blowing direction is upward in a substantially vertical direction, it is preferable that the distance X is greater than 50 mm. Further, as shown in FIG. 9B, in the case of a horizontally oriented nozzle 11b in which the gas blowing direction is substantially horizontal, it is preferable that the distance X is larger than 100 mm. Further, as shown in FIG. 9C, in the case of the obliquely downward nozzle 11c in which the gas blowing direction is obliquely downward, the distance X
Is preferably larger than 100 mm.

(2) Preventing the Granular Materials Around the Communication Port from Stagnation If the particles around the communication port stagnate as shown in FIG. 11, the particles in the communication port will not move. . In order to move this granular material, the fluidized bed height difference between the divided chambers before and after the communication port must be very large (for example,
Uneconomic value of 00 mm).
The presence or absence of the stagnation portion depends on the angle formed by the line connecting the communication port and the gas outlet with respect to the horizontal plane. In general, since the powdery material near the gas blowing nozzle is lifted by the gas flow, as shown in FIG. 12, the line L connecting the corner P on the lower surface of the communication port 9 and the gas blowing port Q is positioned on the horizontal plane. If the angle α is larger than the angle of repose of the granular material, no stagnation portion of the granular material is generated near the entrance of the communication port 9, and the granular material in the communication port 9 moves from the entrance to the exit. However, in practice, it has been found that even if the angle α is slightly smaller than the angle of repose of the granular material, the movement of the granular material in the communication port 9 does not hinder the movement. That is, as shown in FIG. 13, there is no problem if the angle β formed by the line M connecting the corner R of the upper surface of the communication port 9 and the gas outlet Q to the horizontal plane is larger than the angle of repose of the granular material. Do you get it. That is, even if α is smaller than the angle of repose of the granular material and there is a slight stagnant portion near the entrance of the communication port, a considerable amount of the granular material in the vicinity of the line M (below the line M) flows downward. This is because the powder does not substantially prevent the movement of the granular material in the communication port because the powder slides down on the slope with this.

Therefore, it is preferable that the angle formed by the line connecting the corner on the upper surface of the communication port 9 and the gas outlet with respect to the horizontal plane is larger than the angle of repose of the granular material. It is preferable that the relationship between the angles α and β and the angle of repose of the granular material be the same at the outlet of the communication port. The same applies to not only the dispersion plate but also various known gas dispersers.

(3) Others It is preferable that the lower surface of the communication port is located above the tip of the gas outlet nozzle. This is because a stagnant portion is less likely to occur in the communication port. It is preferable that the upstream opening of the communication port gradually decreases in diameter toward the downstream side. This is because the granular material is more likely to enter the communication port. It is preferable that the lower surface portion of the upstream opening of the communication port protrudes upstream from the end surface of the partition plate. This is because a dense downward flow of the granular material easily occurs near the entrance of the communication port. Further, it is preferable that a corner of the upper surface of the protruding portion is cut obliquely. This is because a stagnant portion is less likely to be generated near the entrance of the communication port. It is preferable that the upper surface of the protruding portion is inclined downward from the upstream side to the downstream side. This is because the granular material easily flows through the communication port. It is preferable that the communication port is inclined downward from the upstream side to the downstream side. This is because the granular material easily flows through the communication port. It is preferable that the inclination angle is larger than the angle of repose of the granular material. This is because a stagnation portion hardly occurs. It is preferable that the lower surface portion of the downstream opening of the communication port protrudes downstream from the end face of the partition plate. This is because a dense downward flow of the granular material is formed near the outlet of the communication port.
Further, it is preferable that a corner of the upper surface of the protruding portion is cut obliquely. This is because a stagnant portion is less likely to be generated near the communication port exit. It is preferable that the communication port protrudes from both end faces on the upstream side and the downstream side of the partition plate. This is because, regardless of the thickness of the partition plate, a dense downward flow of the granular material is formed near the entrance side and the exit side of the communication port.

It is preferable that one or a plurality of gas blowing nozzles are provided at an intermediate portion of the communication port, and the reaction gas is blown into the communication port from the gas blowing nozzle. By doing so, it is possible to prevent the granular material from staying in the communication port. As the reaction gas, a part of the gas introduced into the fluidized bed furnace or a gas introduced from the outside can be used. Further, a porous material, for example, a porous refractory (brick) can be used at the tip of the gas blowing nozzle. Further, it is preferable that the tip of the gas blowing nozzle bends obliquely from the upstream side to the downstream side, because the effect of suppressing the stagnation of the granular material in the communication port is further improved.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below together with experimental conditions with reference to the drawings. (1) Experimental conditions (1 example) Granule raw material a Iron ore powder having a bulk specific gravity of 2.0 T / m ³ was charged into a fluidized bed furnace experimental facility at 2.0 T / H. b. Silica powder having a bulk specific gravity of 1.5 T / m ³ was charged into the fluidized bed experimental facility at 2.0 T / H. The fluidized-bed furnace experimental equipment used a plastic cylindrical container capable of clearly observing the flow phenomenon of the granular material inside. The major difference from the actual fluidized bed furnace shown in FIG. 1 is that there is no support pipe 12 for supporting the dispersion plate 2,
That is, the number of the partition plates 5 that partition the fluidized bed 4 is one. The gas used was air and the temperature was room temperature. The height of the communication port provided at the bottom of the partition plate is about 1 of the height of the fluidized bed.
/ 4 or less. The diameter of the communication port was 150 mm. From the above conditions, the average moving speed of the granular material passing through the communication port is 20 mm / sec for iron ore powder and 30 mm / sec for silica stone powder.

(2) Basic type (with the configuration shown in FIG. 8) The length of the communication port 9 is 200 mm. When the blowing direction of the gas blowing nozzle is almost vertically upward, the distance X on the inlet side is 200 mm and the distance X on the outlet side is 200 mm.
And When the blowing direction of the gas blowing nozzle is obliquely downward, the distance X on the inlet side was 250 mm and the distance X on the outlet side was 200 mm. The angle β (see FIG. 13) was 45 ° (the angle of repose of iron ore powder was 40 ° and the angle of repose of quartzite powder was 30 °). A fluidization experiment of iron ore powder or silica stone powder was performed under the above conditions. In any of the powdery and granular materials, the raw material passing through the communication port 9 was fixed at the outlet side due to the pressure difference between the communication port inlet and outlet. While performing a motion of slightly moving to the entrance side after moving a distance, the sub-chamber was moved from the upstream sub-chamber to the downstream sub-chamber without backmixing. In addition, when the blowing direction of the gas blowing nozzle is almost vertically upward, when the distance X on the inlet side of the communication port is 150 mm or less and the distance X on the outlet side of the communication port is 50 mm or less, the gas flows into the communication port, The fluidized bed height difference between the upstream and downstream divided chambers was abnormally large (about 200 mm), and back mixing occurred. Further, when the blowing direction of the gas blowing nozzle is obliquely downward, the same phenomenon occurs when the distance X on the communication port inlet side is 200 mm or less and the distance X on the communication port outlet side is 100 mm or less.

When the angle β is smaller than the angle of repose of the granular material, a stagnant portion is formed near the entrance of the communication port, and the raw material of the granular material cannot move in the communication port.

(3) The upstream opening of the communication port is gradually reduced in diameter toward the downstream side. FIG. 14 (a) shows the upstream opening of the communication port 9 formed in a curved shape. 14 (b) is obtained by obliquely cutting the opening on the upstream side of the communication port, and it can be seen that the raw material of any shape smoothly flows into the communication port 9 in any shape. It could be confirmed.

(4) The lower surface portion of the upstream opening of the communication port is projected upward from the end face of the partition plate. As shown in FIG. When it protrudes toward the upstream side, it can be confirmed that a dense downward flow of the granular material is formed near the entrance of the communication port 9,
It was confirmed that the granular material moved from the inlet to the outlet in the communication port 9 without back mixing.

(5) Obliquely cut corners of the upper surface of the protruding portion shown in FIG. 15 In the case of the configuration shown in FIG. As shown in FIG. 16, it was confirmed that the stagnant portion almost disappeared by obliquely cutting the corner of the upper surface of the lower surface portion 13.

(6) The upper surface of the protruding portion shown in FIG. 15 is inclined downward by 30 ° from the upstream side to the downstream side. As shown in FIG. When inclined 30 ° downward toward the side, the weight of the granular material is added in addition to the fluidized bed pressure difference at the inlet / outlet side of the communication port. Mouth 9
It was confirmed that the movement of the granular material inside was slightly promoted.

(7) The communication port is inclined downward from the upstream side to the downstream side. As shown in FIG. 18, when the communication port 9 is inclined downward by 30 ° from the upstream side to the downstream side. 8, it was confirmed that the movement of the granular material in the communication port was slightly accelerated as compared with the structure shown in FIG. Note that the inclination angle in FIGS. 17 and 18 is preferably about 30 ° or more in order to promote the movement of the granular material.

(8) The lower surface portion of the downstream opening of the communication port is protruded downstream from the end face of the partition plate. As shown in FIG. When projecting toward the downstream side, it can be confirmed that a dense descending flow of the granular material is formed near the outlet of the communication port 9,
It was confirmed that the granular material moved from the inlet to the outlet in the communication port 9 without back mixing.

(9) Obliquely cut corners of the protruding portion shown in FIG. 19 In the case of the configuration shown in FIG. As shown in FIG. 5, it was confirmed that the stagnant portion was almost eliminated by cutting the corner of the upper surface of the lower surface portion 13 obliquely.

(10) A communication port having a length of 100 mm or more protruding toward the upstream side and the downstream side below the partition plate having a thickness of 100 mm or less. In any of the above examples, the partition plate is cut. Although a communication port is provided, it has been confirmed that similar results can be obtained by providing a pipe-shaped communication port 9a in the partition plate 6 as shown in FIG.

(11) A gas outlet nozzle is provided at an intermediate portion of the communication port. FIG. 22 shows a gas outlet nozzle 14 provided at an intermediate portion of the communication port 9, and a gas flows from the gas outlet nozzle 14 into the communication port 9. A part of the reaction gas introduced into the bed furnace is blown out. By doing so, it was confirmed that almost no stagnant portion of the granular material in the communication port 9 was present. FIG. 23 shows a case where a porous material 15 (porous refractory (brick)) is used at the tip of the gas blowing nozzle 14. Thus, even when the tip of the nozzle is made of a porous material, the effect of suppressing the stagnation of the granular material in the communication port 9 can be confirmed as in the case of FIG.

FIG. 24 shows a structure in which three gas blowing nozzles 14a, 14b and 14c are provided in the communication port 9, and the distal ends of the gas blowing nozzles 14a, 14b and 14c are obliquely bent from the upstream side to the downstream side. It is. By doing so, it was confirmed that the stagnation of the granular material in the communication port 9 was completely eliminated.

[0043]

Since the present invention is configured as described above, the following effects can be achieved. According to the first aspect of the present invention, the raw material powder flows upstream in the communication port without back mixing, and while maintaining the height difference of the fluidized bed between the upstream and downstream divided chambers at an appropriate level. A fluidized bed furnace capable of moving from the side to the downstream side can be provided. Therefore, it is possible to realize a fluidized bed furnace with low equipment cost and operation cost.

According to the second aspect of the present invention, it is possible to provide a fluidized bed furnace in which the powder material is less likely to stagnate in the communication port.

According to the third aspect of the present invention, it is possible to provide a fluidized bed furnace in which the powdery material easily flows into the communication port.

According to the fourth aspect of the present invention, it is possible to provide a fluidized bed furnace in which a dense downward flow of the granular material is easily formed near the entrance of the communication port.

According to the fifth aspect of the present invention, it is possible to provide a fluidized bed furnace in which the granular material is unlikely to stay near the entrance of the communication port.

According to the sixth, seventh, and eighth aspects of the present invention, it is possible to provide a fluidized bed furnace in which the granular material is easily moved in the communication port.

According to the ninth aspect of the present invention, it is possible to provide a fluidized bed furnace in which a dense downward flow of the granular material is easily formed near the outlet of the communication port.

According to the tenth aspect of the present invention, it is possible to provide a fluidized bed furnace in which the powder material is less likely to stagnate near the outlet of the communication port.

According to the eleventh aspect of the present invention, a dense downward flow of the granular material is likely to be formed near the entrance / exit of the communication port, and backmixing is unlikely to occur. In addition, it is possible to provide a fluidized bed furnace in which the granular material can move from the upstream side to the downstream side in the communication port.

(10) According to the invention of claims 12, 13 and 14, it is possible to provide a fluidized bed furnace in which the powdery material is less likely to stay in the communication port.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of a multi-chamber split type fluidized bed furnace.

FIG. 2 is a diagram showing a relationship between a raw material ore amount and a furnace residence time in a fluidized bed furnace.

FIG. 3 is a diagram schematically illustrating a state of movement of raw materials in a fluidized bed furnace.

FIG. 4 is a diagram showing a relationship between a raw material ore amount and a residence time in a furnace in a fluidized bed furnace.

FIG. 5 is a diagram illustrating a state of movement of raw materials in a communication port that connects the division chambers.

FIG. 6 is a diagram for explaining the flow of the granular material near the entrance of the communication port.

FIG. 7 is another diagram illustrating the flow of the granular material near the entrance of the communication port.

FIG. 8 shows a distance X between the entrance of the communication port and the end face of the gas blowing nozzle.
FIG.

FIG. 9A is a sectional view of an upward nozzle, and FIG.
FIG. 9B is a cross-sectional view of a horizontal nozzle, and FIG. 9C is a cross-sectional view of an obliquely downward nozzle.

FIG. 10 is a diagram illustrating a state of filling of granular material near a communication port exit.

FIG. 11 is a view for explaining a stagnation state of the granular material near the entrance of the communication port.

FIG. 12 is a diagram illustrating an angle (α) formed by a line connecting a corner P on the lower surface of the opening on the upstream side of the communication port and the gas outlet Q with respect to a horizontal plane.

FIG. 13 is a diagram illustrating an angle (β) formed by a line connecting a corner R on the upper surface of the opening on the upstream side of the communication port and the gas outlet Q with respect to a horizontal plane.

FIG. 14 is a cross-sectional view showing an example in which the upstream opening of the communication port gradually decreases in diameter toward the downstream side.

FIG. 15 is a cross-sectional view showing an example in which the lower surface portion of the upstream opening of the communication port protrudes from the end surface of the partition plate.

16 is a cross-sectional view showing an example in which a corner of the upper surface of the protruding portion in FIG. 15 is obliquely cut.

FIG. 17 is a cross-sectional view showing an example in which the upper surface of the protruding portion in FIG. 15 is inclined downward from the upstream side to the downstream side.

FIG. 18 is a cross-sectional view showing an example in which the communication port is inclined downward from the upstream side to the downstream side.

FIG. 19 is a cross-sectional view showing an example in which the lower surface portion of the downstream opening of the communication port protrudes from the end surface of the partition plate.

20 is a cross-sectional view showing an example in which a corner of the upper surface of the protruding portion in FIG. 19 is obliquely cut.

FIG. 21 is a cross-sectional view showing an example in which communication ports protrude from both end faces on the upstream side and the downstream side of the partition plate.

FIG. 22 is a cross-sectional view showing an example in which a gas blowing nozzle is provided at an intermediate portion of a communication port.

FIG. 23 is a cross-sectional view showing an example in which a porous material is used for a tip portion of a gas blowing nozzle provided at an intermediate portion of a communication port.

FIG. 24 is a cross-sectional view showing an example in which the tip of a gas blowing nozzle provided at an intermediate portion of a communication port is obliquely bent from upstream to downstream.

FIG. 25 is a schematic configuration diagram showing an example of a conventional fluidized bed furnace.

[Explanation of Signs] 1 ... wind box 2, 10 ... gas disperser (dispersion plate) 3, 11, 14, 14a, 14b, 14c ... gas blowing nozzle 4 ... fluidized bed 5, 6 ... partition plate 7 ... upstream division Chamber 8: Downstream split chamber 9, 9a: Connection port 11a: Upward nozzle 11b: Horizontal nozzle 11c: Diagonal downward nozzle 12: Support pipe 13: Lower surface portion

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuo Tsutsumi 1-1, Kawasaki-cho, Akashi-shi, Hyogo Kawasaki Heavy Industries, Ltd. Inside the Akashi Plant (72) Inventor Masahide Kazuki 1-1, Kawasaki-cho, Akashi-shi, Hyogo Inside the Akashi Plant of Kawasaki Heavy Industries, Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) F27B 15/09 F27B 15/10

Claims (14)

(57) [Claims] 1. A reaction is carried out while flowing a granular material supplied from one side by a reaction gas blown from a number of gas blowing nozzles provided in a gas disperser disposed in a lower part of a furnace. A bubbling fluidized bed furnace for discharging products from a side surface, in which a fluidized bed is divided into a plurality of divided chambers by a partition plate, and a raw material is moved from an upstream divided chamber to a downstream divided chamber below the partition plate. A fluidized-bed furnace in which an average moving speed of a raw material passing through the communication port is 500 mm / sec or less, wherein the following conditions are satisfied. When the vertical position of the communication port is 1/4 or less of the height of the fluidized bed, the length of the communication port is 100 mm or more, and the blowing direction of the gas blowing nozzle is almost vertically upward, the upstream of the communication port and upstream The distance from the side nozzle end surface is 15
0 mm, the distance between the outlet of the communication port and the end face of the downstream nozzle is larger than 50 mm, and the blowing direction of the gas blowing nozzle is substantially horizontal.
The distance between the communication port inlet and the upstream nozzle end face is greater than 200 mm, and the distance between the communication port outlet and the downstream nozzle end face is 1 mm.
When the gas outlet nozzle is obliquely downward, the distance between the inlet of the communication port and the end face of the upstream nozzle is larger than 200 mm, and the distance between the outlet of the communication port and the end face of the downstream nozzle is 10 mm.
Greater than 0 mm, the angle between the line connecting the corner of the upper surface of the communication port and the gas outlet with respect to the horizontal plane at both the upstream and downstream openings of the communication port is defined as the angle of repose of the granular material. I made it bigger. 2. The multi-chamber split type fluidized bed furnace according to claim 1, wherein the lower surface of the communication port is located above the blowout portion of the gas blowout nozzle. 3. The multi-chamber split type fluidized bed furnace according to claim 1, wherein the upstream opening of the communication port gradually decreases in diameter toward the downstream side. 4. The multi-chamber split type fluidized-bed furnace according to claim 1, wherein a lower surface portion of the upstream opening of the communication port protrudes upstream from an end face of the partition plate. 5. The multi-chamber fluidized bed furnace according to claim 4, wherein a corner of the upper surface of the protruding portion is cut obliquely. 6. The multi-chamber fluidized bed furnace according to claim 4, wherein the upper surface of the protruding portion is inclined downward from the upstream side to the downstream side. 7. The communication port according to claim 1, wherein the communication port is inclined downward from the upstream side to the downstream side.
The multi-chamber split type fluidized bed furnace according to the above. 8. The multi-chamber split type fluidized bed furnace according to claim 6, wherein the inclination angle is larger than the angle of repose of the raw material. 9. The multi-chamber split type fluidized bed furnace according to claim 1, wherein a lower surface portion of the downstream opening of the communication port projects downstream from an end face of the partition plate. 10. The multi-chamber split type fluidized bed furnace according to claim 9, wherein a corner of the upper surface of the protruding portion is cut obliquely. 11. The multi-chamber fluidized bed furnace according to claim 1, wherein the communication port protrudes from both end faces on the upstream and downstream sides of the partition plate. 12. The multi-chamber split type according to claim 1, wherein one or a plurality of gas blowing nozzles are provided at an intermediate portion of the communication port, and the reaction gas is blown into the communication port from the gas blowing nozzle. Fluidized bed furnace. 13. The multi-chamber split type fluidized bed furnace according to claim 12, wherein a porous material is used at the tip of the gas blowing nozzle. 14. The multi-chamber split fluidized-bed furnace according to claim 12, wherein the tip of the gas blowing nozzle is obliquely bent from the upstream side to the downstream side.