JP2905082B2 - Fluid material circulation method and apparatus - 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 in which fuel such as municipal solid waste, industrial waste and coal is burned in a fluidized bed, and a partition member is provided in the fluidized bed and divided into two chambers. Improvement of the method and apparatus for circulating the fluid material by changing the superficial velocity of the chamber, more specifically, by improving the diffusion and mixing of the fluid material in the chamber with the lower superficial velocity, aiming for efficient heat recovery, and The present invention relates to a method and an apparatus for circulating a fluid material for efficiently burning fuel.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 5-87757 discloses that a fluidized bed is divided into a combustion section and a heat recovery section by a partition plate, and a flow rate of a fluidizing gas blown in the combustion section is determined by a flow rate of a fluidized gas blown in the heat recovery section. The fluidized-bed furnace described above has a configuration in which the fluidized material in the combustion section flows into the heat recovery section over the partition plate by flowing the fluid material in the heat recovery section from the lower part of the partition plate to the combustion section. Have been.

In the fluidized-bed furnace described in this publication, fluidized material flows from a fluidized bed with a high superficial velocity to an upper part of a fluidized bed with a low superficial velocity. As the distance from the partition plate increases, the inflow of the fluid substance decreases. For this reason, even if the width of the fluidized bed having a low superficial velocity is widened, the flow rate of the fluidized material is small and the heat transfer tube cannot be used effectively, so that the width of the fluidized bed is limited.

[0004]

As described above, there is a problem that the amount of the fluid flowing into the upper portion of the fluidized bed having a low superficial velocity decreases with increasing distance from the partition plate. That is, when heat is absorbed from the fluid material, it is necessary to arrange the heat transfer tubes intensively near the partition plate. In addition, the combustion of unburned components flowing in with the fluid material also increases in the vicinity of the partition plate, and there is a problem that oxygen in this portion is insufficient and combustion is deteriorated. For this reason, there has been a demand for a means for dispersing the inflowing fluid in the upper part of the fluidized bed substantially uniformly in a plane direction.

[0005] The present invention has been made in view of the above points,
An object of the present invention is to provide a particle diffusion means in the upper part of the fluidized bed with a lower superficial velocity to horizontally disperse the fluid substance flowing from the fluidized bed with the higher superficial velocity beyond the upper end of the partition plate. It is an object of the present invention to provide a method and an apparatus for circulating a fluid material, in which heat is efficiently recovered by dispersing the fluid substantially uniformly in the direction and the flammability is improved.

[0006]

As described above, when a fluid material flows from a fluidized bed with a high superficial velocity to the upper part of a fluidized bed with a low superficial velocity, as described above, the fluid substance is inflowed closer to the partition plate. And the inflow of the fluidized material decreases as the distance from the partition plate increases. FIG. 14 shows that the first chamber has a fluidization start flow rate of 4
FIG. 9 shows test results obtained by measuring the amount of circulating fluid to the second chamber when the second chamber was fluidized at a gas flow rate 1.5 times the fluidization start flow rate at twice the gas flow rate. . FIG. 14 shows that the amount of circulation to the vicinity of the partition plate is very large.

[0007] Generally, the diffusion of a fluid substance in a fluidized bed is fast in the vertical direction, but slow in the horizontal direction. For this reason, even if the width of the fluidized bed in the second chamber is widened, the fluid material flowing from the first chamber and the unburned material flowing along with the fluid material are provided at a position distant from the partition plate. Heat tubes cannot be effectively recovered. Further, the method of burning unburned components cannot completely burn unburned components. In order to solve these problems, a means for reducing the vertical diffusion is provided in the upper region of the fluidized bed of the second chamber. As a result, the fluid flowing from the first chamber is reduced by the horizontal diffusion. It can be distributed almost uniformly in the upper region of the two fluidized beds. This allows efficient heat recovery in the second chamber. Further, in the second chamber, unburned components flowing from the first chamber together with the fluid material can be efficiently burned.

In order to achieve the above object, according to the method for circulating fluidized material of the present invention, a chamber provided with a fluidized bed is divided into two chambers by a partition member having openings at upper and lower portions, respectively. In the method in which the superficial velocity is changed and the fluid material is circulated through the opening , the fluid material is dispersed horizontally in the upper part of the fluidized bed of the chamber with the smaller superficial velocity.
So that the fluid substance flows into the position away from the partition member
For diffusing the fluid material circulated from the upper opening of the partition member.

In the fluidized material circulation apparatus of the present invention, a fluidized bed formed by air blown upward from an air distribution plate and a chamber provided with the fluidized bed are formed at a lower end portion and an upper portion of the fluidized bed above the stationary bed height. And a second chamber having a heat transfer tube in a fluidized bed and a separate chamber provided below the first and second chambers, respectively. It consists of a windbox having a blowing amount adjusting mechanism, in a fluidized material circulation apparatus that superficial velocity of the first chamber is greater than the superficial velocity of the second chamber, the fluidized bed above the second chamber, the flow Partition material by dispersing the substance horizontally
To allow the flow of material to flow away from
It is characterized in that a particle spreading means.

In the above apparatus, the first chamber is a combustion chamber,
The second chamber may be configured as a heat recovery chamber, or the first chamber may be configured as a partial combustion chamber, and the second chamber may be configured as a combustion chamber. A heat transfer tube is provided below the particle diffusing means in the fluidized bed of the second chamber. The particle diffusion means is the top heat transfer tube
The uppermost heat transfer tube is covered with a cover, and a gap is formed between the covers. A gap is formed between them, or a fin is provided with an opening. The shape of the holes in the perforated plate can be circular, triangular, square, polygonal, or any other shape.

The porosity of the particle diffusion means is 5 to 50%, preferably 10 to 30%. If it is smaller than this range, the movement of particles from the opening to the lower part of the fluidized bed will be poor. Further, since the gas flow velocity passing through the opening increases, the abrasion of the particle diffusion means tends to increase. On the other hand, if it is larger than this range, the effect of suppressing the vertical diffusion tends to decrease. Further, the opening of the particle diffusing means may be configured to increase as the distance from the partition member increases, or the particle diffusing means may be arranged so as to be inclined such that the one closer to the partition member is upward. .

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. However, the shapes of the components described in this embodiment, the relative arrangement thereof, and the like are not intended to limit the scope of the present invention to them only, unless otherwise specified, and are merely illustrative examples. It's just Embodiment 1 One embodiment of a method and apparatus for circulating a fluid substance according to the present invention will be described with reference to FIG. Reference numeral 1 denotes an apparatus body having a water-cooled tube structure (a refractory material structure is also possible). Reference numeral 2 denotes a fluidized bed combustion chamber to which, for example, industrial waste having a calorific value of 4000 Kcal / kg is supplied from a fuel supply port 18. Wind box 7 provided at the lower part of fluidized bed combustion chamber 2
The fluid is fluidized by the air supplied through the air dispersing plate 6 to burn the fuel. The main body 1 is divided by a partition member 3 into a fluidized bed heat recovery chamber 4 separate from the combustion fluidized bed 2, a heat transfer tube 5 is provided in the bed, and a lower wind box 8
The fluidized material is fluidized by the air supplied from the air through the air distribution plate 6, and the heat is absorbed by the heat transfer tube 5.
The heat transfer tube 5 is a superheater tube (or a reheat tube or a water-cooled tube).

The fluidized particles are composed of particles of about 0.5 to 1 mm, and limestone, dolomite or the like is supplied as a desalinating agent or desulfurizing agent as required, and the fluidization starting speed is 3 to 5 with air from below. Fluidizes at about double the superficial velocity and burns fuel. Combustion chamber 2
Is generally about 550-900 ° C., and for that purpose, for example, 550-700 ° C. under the conditions for performing desalination,
Under the conditions for performing desulfurization, the temperature is designed to be a predetermined temperature such as about 750 to 850 ° C. If the calorific value of the fuel is high, the combustion temperature increases. Therefore, a part of the heat generated by the combustion is collected by the heat transfer tube 5 of the heat recovery chamber 4 so as to reach a predetermined combustion temperature. The heat recovery chamber 4 is provided with necessary heat transfer tubes 5 designed and calculated in advance.

From the combustion chamber 2, a high-temperature fluid substance is supplied from the upper part of the partition member 3 having a water-cooled pipe structure (or may be a refractory material structure), preferably from an opening 19 provided at a position equal to or higher than the height of the stationary layer. Then, the predetermined heat is removed by the heat transfer tube 5, and the cooled fluid material is circulated to the combustion chamber 2 from the opening 20 provided at the lower part of the partition member 3. As shown in FIG. 1, the particle diffusion means 51 is provided in the upper region 50 of the heat recovery chamber 4.
Is provided. As shown in FIG. 2, a porous plate 52 having a porosity of 5 to 50% is used as the particle diffusion means 51. 54 is a hole. Also, as shown in FIG.
In some cases, the perforated plates 56 are arranged so that the size of the perforated plate 4 increases as the distance from the partition member increases. As shown in FIG. 4, these perforated plates 52 and 56 may be arranged so as to be inclined such that the side closer to the partition member 3 is upward.

Further, as shown in FIG. 5, the uppermost heat transfer tube 5 is covered with a cover 58, and a particle diffusion means is formed by forming an opening between the covers, or as shown in FIG. The fins (fins) 60 may be provided in the upper heat transfer tube 5 so that the space between the fins is used as an opening to constitute the particle diffusion means. Further, as shown in FIG. 7, the uppermost heat transfer tubes 5 may be connected to each other by fins (fins) 62, and the fins 62 may be provided with openings 64. The opening 64 may be provided to fill the width of the fin 62 as shown in FIG. Also, the shape of the opening 64,
The arrangement can be circular as shown in FIG. 9 or increased in the number of apertures 64 as shown in FIG. The shape, size, and number of the openings 64 are not limited to the above figures, and may be appropriately changed to any shape, size, and number.

When the particle diffusing means 51 is not provided, a large amount of fluid flows into the area a if the width of the heat recovery chamber 4 is considered as areas a, b, c and d as the distance from the partition member 3 increases. However, since the amount of the inflow material into the region d is very small, the heat transfer tube 5 in this region cannot effectively recover heat. However, the upper area 5 of the heat recovery chamber 4
0, the particle diffusion means 51 is provided.
The fluidized material flowing in at the upper part of 1 moves toward the lower part of the fluidized bed while being mixed almost uniformly in the width direction of c and d, so that the heat transfer tubes 5 can be arranged effectively. In addition, since the width of the heat recovery chamber 4 can be effectively used, the number of heat transfer tubes used is reduced, and the heat recovery chamber 4 can be designed to be compact.

The circulation of the fluid material is performed as follows.
That is, if the superficial velocity of the combustion chamber 2 is made higher than the superficial velocity of the heat recovery chamber 4, the fluid material moves from the upper part of the combustion chamber 2 to the upper part of the heat recovery chamber 4 through the upper opening 19, It passes through the interior of the recovery chamber 4 and circulates from the lower opening 24 to the combustion chamber 2. If the superficial tower speed in the heat recovery chamber 4 is increased, the circulation is naturally reversed. The temperature and / or heat recovery amount of the combustion chamber 2 is controlled by changing the superficial velocity of the heat recovery chamber 4 and / or the superficial velocity of the combustion chamber 2. 40 is an air supply pipe, 41,
42 is an air flow rate adjusting means (a valve, a damper, etc.).
FIG. 1 shows a case where one heat recovery chamber 4 is provided for one combustion chamber 2. However, as shown in FIG. 11, the combustion chamber 2 is rectangular and a plurality of heat recovery chambers 4 are provided. (In FIG. 11, four as an example). Of course, a circle may be used instead of a rectangle. In some cases, the combustion chamber 2 may be configured as a partial combustion chamber, and the heat recovery chamber 4 may be configured as a combustion chamber. In this case, it is preferable to embed a heat transfer tube in the fluidized bed of the combustion chamber to form a combustion / heat recovery chamber.

Embodiment 2 In this embodiment, as shown in FIG. 12, an incombustible discharge pipe 13 is provided through the wind box 7 of the partial combustion chamber 2a. (A valve, a damper, etc.) and a partial combustion chamber 2a
The temperature detection control means 31 is connected to the fluidized bed of this, the temperature detection control means 31 and the air flow rate adjustment means 30 are connected,
The fluidized bed temperature of the partial combustion chamber 2a is controlled by the amount of air supplied to the incombustible discharge pipe 13. The fluid material containing incombustible material extracted from the incombustible discharge pipe 13 is separated into coarse incombustible material and fluid material by a classifier 15 such as a sieve, and the coarse incombustible material is discharged out of the system. The fluid material is circulated and reused in the partial combustion chamber 2a.
In addition, it is also possible to circulate the fluid substance to the combustion chamber (combustion / heat recovery chamber) 4a. It is also possible to use the partial combustion chamber 2a as a combustion chamber and the combustion chamber 4a as a heat recovery chamber.

If the air supply method as shown in FIG. 12 is adopted, the circulation of the fluid material is controlled by the partial combustion chamber 2a of the partition member 3.
The superficial velocity on the side, that is, the superficial velocity near the upper opening 14 of the incombustible discharge pipe 13 is higher than the superficial velocity on the combustion chamber 4 a side of the partition member 3. Generally, the superficial velocity near the upper opening 14 of the incombustible discharge pipe 13 is set to 3 to 5 times the fluidization start velocity, and the superficial velocity at the combustion chamber 4a side of the partition member 3 is changed from the fluidization start flow velocity to the flow velocity. The circulation of the fluid substance is performed at about twice the flow rate at the start of the formation. The temperature of the partial combustion chamber 2a is adjusted by adjusting air supplied to the incombustible discharge pipe 13 by the air flow rate adjusting means 30. When the air supplied from the incombustible discharge pipe 13 is stopped, fluidization of the fluidized bed portion of the incombustible discharge pipe 13 stops, and the fluidized bed portion becomes stationary. The upper opening 19 of the partition member 3 is provided between the partial combustion chamber 2a and the combustion chamber 4a.
The fluid material is alternately moved between the partial combustion chamber 2a and the small amount, and the heat is hardly removed from the partial combustion chamber 2a. As described above, when it is not necessary to remove heat from the partial combustion chamber 2a, for example, at the time of startup, the air in the combustion chamber 4a may also be stopped.

When the flow rate of the air from the incombustible discharge pipe 13 is increased to be in a fluidized state, the flowable material in the combustion chamber 4a moves from the lower opening 20 to the partial combustion chamber 2a, and thereby, from the upper opening 19. The high-temperature fluid material in the partial combustion chamber 2a moves to the combustion chamber 4a, receives heat from the heat transfer tube 5, is cooled, and is circulated to the partial combustion chamber 2a. Chamber 2a and combustion chamber 4
If the superficial velocity of a is constant, it increases as the flow rate of the air supplied to the incombustible discharge pipe 13 increases. Thus, the temperature of the partial combustion chamber 2a can be controlled to a predetermined fluidized bed temperature by adjusting the amount of air supplied to the incombustible discharge pipe 13. In addition, the incombustible discharge pipe 13
The amount of heat to be recovered can be controlled by adjusting the flow rate of the air supplied to the heater.

In the apparatus shown in FIG. 12, the combustion chamber 4a
Since the temperature of the fluidized bed rises due to the combustion in, the heat transfer tube 5 is provided in the fluidized bed to collect heat and reach a predetermined temperature. The configuration of the particle diffusing unit 51 is the same as that of the first embodiment. As shown in FIG. 13, the partial combustion chamber 2a
May be rectangular, and the number of combustion chambers 4a may be plural (four in FIG. 13 as an example). Of course, a circle may be used instead of a rectangle. Other configurations and operations are the same as those of the first embodiment. Further, it is of course possible to apply the air supply method as shown in FIG. 12 to an apparatus including the combustion chamber 2 and the heat recovery chamber 4 shown in FIG.

[0022]

As described above, the present invention has the following effects. (1) In the upper part of the fluidized bed in the second chamber , the fluid material is placed horizontally.
And the fluid substance flows to a position distant from the partition member.
Since the particle diffusing means for allowing the fluid to enter is provided, diffusion and mixing of the fluid in the second chamber is improved, and the fluid is uniformly dispersed, so that heat can be efficiently recovered. (2) For the same reason, in the second chamber, the unburned portion that has flowed in from the first chamber together with the fluid substance can be efficiently burned. (3) Disperse the fluid material in the horizontal direction from the partition member
Since the width of the heat recovery chamber can be effectively used by the particle diffusion means for allowing the fluid to flow into a distant position, the number of heat transfer tubes used is reduced, and The size of the collection chamber can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of a fluidized matter circulation device of the present invention.

FIG. 2 is a plan view showing an example of a particle diffusing unit in FIG.

FIG. 3 is a plan view showing another example of the particle diffusion means.

FIG. 4 is a schematic configuration diagram showing another embodiment of the apparatus of the present invention.

FIG. 5 is a cross-sectional view showing another example of the particle diffusion means.

FIG. 6 is a cross-sectional view showing another example of the particle diffusion means.

FIG. 7 is a plan view showing another example of the particle diffusion means.

FIG. 8 is a plan view showing another example of the particle diffusion means.

FIG. 9 is a plan view showing another example of the particle diffusion means.

FIG. 10 is a plan view showing still another example of the particle diffusion means.

FIG. 11 is an explanatory plan view showing an example of arrangement of a combustion chamber and a heat recovery chamber in the apparatus of the present invention.

FIG. 12 is a schematic configuration diagram showing still another embodiment of the device of the present invention.

FIG. 13 is an explanatory plan view showing an arrangement example of a partial combustion chamber and a combustion chamber in the apparatus of the present invention.

FIG. 14 is a graph showing a relationship between a distance from a partition plate and a circulating amount of a fluid substance.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Device main body 2 Combustion chamber 2a Partial combustion chamber 3 Partition member 4 Heat recovery chamber 4a Combustion chamber (combustion / heat recovery chamber) 5 Heat transfer tube 6 Air dispersion plate 7 Wind box 8 Wind box 13 Noncombustible material discharge conduit 14 Upper opening 15 Classification Apparatus 18 Fuel supply port 19 Upper opening 20 Lower opening 30 Air flow control means 31 Temperature detection control means 40 Air supply pipe 41 Air flow control means 42 Air flow control means 50 Upper area 51 Particle diffusion means 52 Perforated plate 54 Hole 56 Perforated plate 58 Cover 60 Fin 62 Fin 64 Opening

Continuation of front page (56) References JP-A-63-180086 (JP, A) JP-A-63-14086 (JP, A) JP-A-5-340681 (JP, A) JP-A-63-183380 (JP) , A) JP-A-3-70992 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F28D 1/00-13/00

Claims (11)

(57) [Claims] 1. A method in which a chamber provided with a fluidized bed is divided into two chambers by a partition member having upper and lower openings, and a fluid material is circulated through the openings by changing the superficial velocity of each chamber. At the top of the fluidized bed in the chamber with the lower superficial velocity ,
Dispersed in the horizontal direction and flowed away from the partition member
A method for circulating a fluid material, comprising: providing a particle diffusing means for allowing a material to flow therein; and diffusing the fluid material circulated from an upper opening of the partition member. 2. A fluidized bed formed by air blown upward from an air distribution plate, and a partition member having an opening in a lower end portion and an upper portion of the fluidized bed above the stationary bed height. Wind having a first chamber and a second chamber having a heat transfer tube in a fluidized bed formed separately from each other, and an independent air blowing amount adjusting mechanism provided below the first chamber and the second chamber, respectively. In a fluidized material circulating apparatus comprising a box, wherein the superficial velocity of the first chamber is higher than the superficial velocity of the second chamber , the fluidized material is horizontally dispersed in the upper part of the fluidized bed of the second chamber.
Fluid material will flow into the area away from the partition
Flow material circulating apparatus characterized in that a particle diffuser means for sea urchin. 3. The fluidized matter circulation device according to claim 2, wherein the first chamber is a combustion chamber, and the second chamber is a heat recovery chamber. 4. The apparatus according to claim 2, wherein the first chamber is a partial combustion chamber, and the second chamber is a combustion chamber. 5. A heat transfer tube is provided below the particle diffusing means in the fluidized bed of the second chamber.
A fluid material circulation device as described in the above. 6. The method according to claim 1, wherein the particle diffusion means is located above the uppermost heat transfer tube.
It is a perforated plate provided in, The claim 2 characterized by the above-mentioned.
6. The fluid substance circulating apparatus according to any one of 5. 7. The apparatus according to claim 2, wherein the particle diffusion means covers the uppermost heat transfer tube with a cover so that a gap is formed between the covers. Fluid material circulation device. 8. The particle diffusion means, wherein a fin is provided on the uppermost heat transfer tube, and a gap is formed between the fins, or an opening is provided in the fin. Item 7. A fluid material circulating apparatus according to any one of Items 2 to 6. 9. The fluidized matter circulation device according to claim 2, wherein the porosity of the particle diffusion means is 5 to 50%. 10. The fluidized matter circulating apparatus according to claim 2, wherein the opening of the particle diffusing means increases with distance from the partition member. 11. The fluidized matter circulating apparatus according to claim 2, wherein the particle diffusing means is arranged so as to be inclined such that a part closer to the partition member is upward.