JPH07269829A - Method and apparatus for partitioning fluidized bed - Google Patents

Abstract

PURPOSE:To reduce wear of a partition member of a fluidized bed in a fluidized- bed furnace in which fluidized substance is circulated between first and second chambers. CONSTITUTION:A method for burning a fluidized bed has the steps of dividing a chamber having a fluidized bed to two chambers 2, 4 by a partition member 3a having openings 19, 20 at upper and lower parts, varying superficial velocities of the chambers 2, 4 and circulating fluidized substance through the openings 19, 20, and comprises the step of disposing the member 3a in the bed by deviating it to the chamber 4 having smaller superficial velocity than that of a partition member 3b of a plenum chamber, thereby reducing wear of the member 3a of the bed.

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 fluidized bed combustion of fuel such as municipal solid waste, industrial waste, and coal, which is divided into two chambers by providing a partition member in the fluidized bed. An improvement of a method and an apparatus for circulating a fluid substance by changing the superficial velocity of a chamber, more specifically, to a partition method and an apparatus for arranging a partition member so as to reduce wear of the partition member provided in a fluidized bed. is there.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 9, a fluidized bed in a main body 1 of an apparatus is divided into a combustion chamber 2 and a heat recovery chamber 4 by a partition member 3a, and the amount of fluidized gas blown into the combustion chamber 2 is increased. Collection room 4
Is larger than the fluidized gas blown into the heat recovery chamber 4 from the upper opening 19 of the partition member 3a and the flow material of the heat recovery chamber from the lower opening 20 of the partition member 3a. There is known a fluidized bed furnace in which the gas is returned to the combustion chamber 2 (for example, Japanese Patent Publication No. 5-87757).
(See the official gazette). 3b is a partition member of the wind box, and 6 is an air dispersion plate.

In FIG. 9, the partition member 3a of the fluidized bed is vertically provided directly above the partition member 3b of the wind box, but as shown in FIG. 10, the partition member 3b of the wind box is provided.
There is also known a fluidized bed furnace in which a partitioning member 3a of the fluidized bed is provided above the above (see, for example, Japanese Patent Publication No. 5-87759).
(See the official gazette).

[0004]

In an apparatus in which a fluidized bed is partitioned by a partition member into two chambers, generally,
Make the superficial velocity of the first chamber faster than the superficial velocity of the second chamber,
The fluid material is moved from the upper opening of the first chamber to the upper portion of the second chamber and circulated from the lower opening of the second chamber to the lower portion of the first chamber. Since the superficial velocity is higher on the first chamber side of the partition member than on the second chamber side, the first chamber side of the partition member is in a condition of being more worn than the second chamber side, which is a problem. . The partition member shown in FIGS. 9 and 10 has a problem that the wear on the first chamber side 2 of the partition member is larger than that on the second chamber side 4.

The thickness reduction of the material of the partition member (the reduction of the thickness of the material, that is, the thickness) is due to wear or corrosion, and when both occur at the same time, the thickness reduction is accelerated. It Fluidized bed combustion is in a situation where such wear and corrosion occur at the same time. FIG. 7 shows an example of superficial velocity of the combustion chamber 2 and the heat recovery chamber 4. In the combustion chamber 2, a fluidized substance with a fluidization initiation speed of 0.2 m / s
The double superficial velocity is 1.0 m / s, and the heat recovery chamber 4 is double the superficial velocity of 0.4 m / s. Therefore, since the superficial velocity is higher on the combustion chamber side a of the partition member 3a than on the heat recovery chamber side, the wear of the partition member on the combustion chamber side is significantly greater than on the heat recovery chamber side. Therefore, by moving the fluidized-bed partitioning member 3a to the heat recovery chamber side relative to the position of the partitioning member 3b of the air box, the superficial velocity of the fluidized-bed partitioning member 3a on the combustion chamber side becomes slower. Become.

As the partition member 3a in the fluidized bed is moved closer to the combustion chamber than the partition member 3b of the wind box, the slow superficial velocity of the heat recovery chamber 4 is approached, which is preferable in terms of wear. However, the amount of the fluid substance circulated from the combustion chamber 2 to the heat recovery chamber 4 decreases, which is not preferable. According to the test, from the intersection of the partition member 3b of the wind box and the air distribution plate 6,
An angle θ3 (see FIGS. 5 and 6) between the line connecting the upper ends of the lower openings 20 of the in-layer partition members 3a and the line extending vertically the intersection of the partition member 3b of the wind box and the air distribution plate 6 is 45. It has been clarified that if the degree of excess is exceeded, the circulating amount of the fluid substance becomes small, which is not preferable.

A method in which heat generated by combustion in the combustion chamber 2 is applied to a fluid substance, the fluid substance is moved to the heat recovery chamber 4 and the heat is recovered in the heat transfer tube 5 is S contained in the fuel. SO ₂ or HC, which is a combustible organism such as
The purpose is to protect the heat transfer tubes from corrosive gases such as l. FIG. 8 illustrates the state of CO diffusion when CO is supplied as a simulated gas into the fluidized bed from the lower part of the fluidized bed, and a CO spread angle (θ1) of about 20 degrees was obtained.

When the spread angle (θ1) of the gas is 20 degrees, that is, when the spread angle (θ1 / 2) to one side is 10 degrees, the gas spreads. If the partition member 3a is not arranged within this 10 degrees, It was clarified that the thickness reduction of the partition member due to corrosion is reduced. Above the opening 19 at the upper part of the partition member 3a, since there is less fluid substance and less thinning due to wear, it is arranged outside the diffusion region of the combustion chamber side gas at least up to the upper opening 19 of the partition member 3a. By
It is possible to significantly reduce metal loss.

The present invention has been made in view of the above points, and an object of the present invention is to dispose the partitioning member of the fluidized bed by displacing it to the second chamber side having a lower superficial velocity. It is an object of the present invention to provide a method and an apparatus that significantly reduce the wear of partition members.

[0010]

[Means and Actions for Solving the Problems] Since the wear of the heat transfer tubes and the like provided in the fluidized bed increases as the superficial velocity increases, the partition member is moved to the second chamber side where the superficial velocity is low. It has been revealed that it is possible to significantly reduce the wear by arranging them in such a manner. At this time, as shown in FIG. 5, the angle θ3 between the virtual line connecting the upper end of the lower opening 20 of the partition member and the upper end of the partition member 3b of the wind box and the center line of the partition member 3b of the wind box is 45 degrees. It has been clarified that it is preferable to select a value smaller than 45 degrees for the angle θ3 because the circulation amount sharply decreases when the value exceeds. However, if this angle is too small, wear occurs, so θ3 must be 15 degrees or more.

In order to achieve the above object, the method of partitioning a fluidized bed of the present invention divides a chamber equipped with a fluidized bed into two chambers by partitioning members having openings (communication ports) in the upper and lower portions, respectively. In the fluidized bed combustion method in which the superficial velocity of each chamber is changed to circulate the fluid substance through the opening, the partition member in the fluidized bed is shifted to the chamber side having a lower superficial velocity than the partition member of the wind box. Is arranged in order to reduce the wear of the partition member of the fluidized bed.

In the fluidized bed partitioning device of the present invention, the fluidized bed formed by the air blown upward from the air dispersion plate and the chamber provided with the fluidized bed are opened at the lower end and the upper end, respectively (communication ports). A first chamber and a second chamber that are formed by being divided by a partition member having a), and a wind box that is provided on the lower side of the first chamber and the second chamber and that has an independent air blowing amount adjusting mechanism. Therefore, in the fluidized bed combustion apparatus in which the superficial velocity of the first chamber is made higher than the superficial velocity of the second chamber,
It is characterized in that the partition member in the fluidized bed is arranged so as to be displaced toward the chamber side having a lower superficial velocity than the partition member of the wind box. It is preferable that the upper opening (communication port) is provided above the stationary bed height of the fluidized bed so that the fluid substance moves through the communication port when the fluidized bed is in a fluidized state.
Of course, it is also possible to position the upper opening (communication port) below the height of the stationary layer.

In the above apparatus, the first chamber is the combustion chamber,
The second chamber is configured as a heat recovery chamber having a heat transfer tube, the first chamber is configured as a partial combustion chamber, and the second chamber is configured as a combustion chamber, or the first chamber is configured as a partial combustion chamber. Then, the second chamber may be configured as a combustion / heat recovery chamber provided with a heat transfer tube.
In this case, as shown in FIG. 5, an angle (θ3) between a virtual line connecting the upper end of the lower opening 20 of the partition member 3a and the upper end of the partition member 3b of the wind box and the center line of the partition member 3b of the wind box. Is 1
The partition member 3a is provided in the fluidized bed so that the range is 5 to 45 degrees.
Is preferably provided.

Further, as shown in FIG. 6, the partition member 3a
The angle (θ3) between the imaginary line connecting the upper end of the lower opening 20 and the upper end of the partition member 3b of the wind box and the center line of the partition member 3b of the wind box is smaller than 45 degrees, and the partition member 3a An angle (θ2) between a virtual line connecting the lower end of the upper opening 19 and the upper end of the partition member 3b of the wind box and the center line of the partition member of the wind box.
The partition member 3 in the fluidized bed so that
It is preferable to provide a. With this configuration, the lower end of the upper opening 19 of the partition member 3a is located outside the value of the angle θ2.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the drawings. However, the dimensions, shapes, relative arrangements, and the like of the constituent members described in this embodiment are not intended to limit the scope of the present invention thereto, unless otherwise specified, and are merely It's just an example. Embodiment 1 An embodiment of the method and apparatus for partitioning a fluidized bed of the present invention is shown in FIG.
Explained by. Reference numeral 1 denotes a main body of the apparatus, which is manufactured with a water-cooled pipe structure (a refractory material structure is also possible), and 2 denotes a fluidized bed combustion chamber, for example, industrial waste having a calorific value of 4000 kcal / kg is supplied from a fuel supply port 18. Air supplied from a wind box 7 provided in the lower part of the fluidized bed combustion chamber 2 through an air dispersion plate 6 fluidizes a fluid substance to burn fuel. The main body 1 is divided into a fluidized bed heat recovery chamber 4 separate from the combustion fluidized bed 2 by an in-layer partition member 3a, and a heat transfer tube 5 is provided in the bed.
Air is supplied from the lower air box 8 through the air dispersion plate 6 to fluidize the fluid material, and the heat transfer tube 5 absorbs heat. The heat transfer tube 5 is a superheater tube (or a reheat tube or a water cooling tube).

The fluidized material particles are composed of particles of about 0.5 to 1 mm, and limestone, dolomite and the like are supplied as a desalting agent or a desulfurizing agent, if necessary, and the air from the lower part has a fluidization initiation speed of 3 to 3 It fluidizes and burns fuel at a superficial velocity of about 5 times. The temperature of the combustion chamber 2 is generally 550 to 9
The temperature is about 00 ° C., and for that purpose, for example, 550 to 700 ° C. under the conditions for carrying out desalting and 75 under the conditions for carrying out desulfurization.
It is designed to have a predetermined temperature such as 0 to 850 ° C. Since the combustion fluidized bed temperature increases when the calorific value of the fuel is high, a part of the heat generated by the combustion is collected by the heat transfer tube 5 of the heat recovery chamber 4 to reach a predetermined combustion temperature. The heat recovery chamber 4 is provided with necessary heat transfer tubes whose design is calculated in advance.

From the combustion chamber 2, the high-temperature fluid substance is heat-recovered from the upper part of the in-layer partition member 3a of the water-cooled pipe structure (or the refractory structure may be used), preferably the opening 19 provided at a level equal to or higher than the height of the stationary layer. After moving to the chamber 4 and removing a predetermined amount of heat by the heat transfer tube 5, the cooled fluidized material is transferred to the in-layer partition member 3
It is circulated to the combustion chamber 2 through an opening 20 provided in the lower part of a. Reference numeral 40 is an air supply pipe, and 41 and 42 are air flow rate adjusting means (valves, dampers, etc.).

The lower opening 2 of the in-layer partition member 3a shown in FIG.
As shown in FIG. 5, the upper end of 0 is, for example, 300 mm above the upper surface of the air dispersion plate. On the other hand, the in-layer partition member 3a
Are arranged so as to be displaced, for example, by 200 mm from the partition member 3b of the wind box toward the second chamber (heat recovery chamber) side. Angle θ3 at this time
Is approximately 33 degrees. Thus, the intra-layer partition member 3
By providing a on the side of the second chamber, the superficial velocity on the combustion chamber (first chamber) side of the in-layer partition member 3a becomes approximately equal to the superficial velocity on the second chamber side, and The wear of the member 3a was significantly reduced.

FIG. 6 shows a preferred arrangement example of the partition member 3a. That is, a line connecting the lower end of the upper opening 19 of the partition member 3a to the lower end of the upper opening 19 and the upper end of the partition member 3b of the wind box (intersection point of the partition member 3b of the wind box and the air distribution plate), The partition member 3b of the box is arranged outside this angle (θ2) so that the angle (θ2) with the extension of the vertical line is greater than 10 degrees, and the upper end of the lower opening 20 of the partition member 3a. The partition member 3a is arranged so that the angle (θ3) between the intersection of the partition member 3b of the wind box and the air dispersion plate 6 is smaller than 45 degrees. That is, the partition member 3 in the layer
It is preferable to arrange a so that the angle (θ2) is larger than 10 degrees and the angle (θ3) is smaller than 45 degrees.

FIG. 4 shows the in-layer partition member 3a when two heat recovery chambers 4 are provided for one combustion chamber 2. In addition to this, a plurality of heat recovery chambers may be arranged around one combustion chamber. In addition,
The partition member 3a on the upper side of the upper opening (communication port) 19 is not always necessary and can be omitted.

Embodiment 2 In this embodiment, as shown in FIG. 2, the first chamber is a partial combustion chamber 2
a and the second chamber as a combustion chamber 4a so that the unburned component in the fluid material that has moved from the partial combustion chamber 2a to the combustion chamber 4a through the upper opening 19 of the partition member 3a is burned in the combustion chamber 4a. It is configured in. Other configurations and operations are similar to those of the first embodiment.

Embodiment 3 In this embodiment, as shown in FIG. 3, the first chamber is replaced by the partial combustion chamber 2
a and the second chamber is a combustion / heat recovery chamber 4b equipped with a heat transfer tube 5.
As the temperature of the fluidized bed in the chamber 4b rises due to the combustion of unburned components, the heat is collected in the heat transfer tube 5 to a predetermined temperature. Other configurations and operations are similar to those of the first embodiment.

[0023]

Since the present invention is configured as described above, it has the following effects. (1) By arranging the partitioning member of the fluidized bed so as to be displaced toward the second chamber side having a lower superficial velocity, the wear of the partitioning member of the fluidized bed can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a fluidized bed partitioning device of the present invention.

FIG. 2 is a schematic configuration diagram showing another embodiment of the apparatus of the present invention.

FIG. 3 is a schematic configuration diagram showing still another embodiment of the device of the present invention.

FIG. 4 is an explanatory view showing an arrangement example of a combustion chamber and a heat recovery chamber in the device shown in FIG.

FIG. 5 is an explanatory diagram showing dimensions and angles of each part in the device of the present invention.

FIG. 6 is an explanatory diagram showing angles of each part in the device of the present invention.

FIG. 7 is an explanatory view showing an example of a conventional fluidized bed furnace and showing superficial velocity of each part.

FIG. 8 is an explanatory view showing a fluidized bed furnace used in the experiment of the present inventor and the result thereof.

FIG. 9 is an explanatory diagram showing an example of a conventional fluidized bed furnace.

FIG. 10 is an explanatory diagram showing another example of a conventional fluidized bed furnace.

[Explanation of symbols]

 1 Device Main Body 2 Combustion Chamber 2a Partial Combustion Chamber 3a Partition Member of Fluidized Bed 3b Partition Member of Air Box 4 Heat Recovery Chamber 4a Combustion Chamber 4b Combustion / Heat Recovery Chamber 5 Heat Transfer Tube 6 Air Dispersion Plate 7 Air Box 8 Air Box 18 Fuel Supply port 19 Upper opening 20 Lower opening 40 Air supply pipe 41 Air flow rate adjusting means 42 Air flow rate adjusting means

Claims (7)

[Claims] 1. A flow in which a chamber provided with a fluidized bed is divided into two chambers by partitioning members each having an opening in the upper part and a lower part, and the superficial velocity of each chamber is changed to circulate a fluid substance through the opening. In the laminar combustion method, the partitioning member in the fluidized bed is arranged so as to be displaced toward the chamber side having a lower superficial velocity than the partitioning member of the wind box to reduce wear of the partitioning member of the fluidized bed. Layer partition method. 2. A fluidized bed formed by air blown upward from an air dispersion plate and a chamber provided with the fluidized bed are formed by partitioning members having openings at the lower end and the upper end, respectively. It is composed of a first chamber and a second chamber, and a wind box provided on the lower side of the first chamber and the second chamber, which is provided with an independent air blowing amount adjusting mechanism, and the superficial velocity of the first chamber is the second chamber. In a fluidized bed combustor designed to be faster than the superficial velocity of the chamber, the partitioning member in the fluidized bed is arranged so as to be shifted toward the chamber having a lower superficial velocity than the partitioning member of the wind box. Layer partition device. 3. The fluidized bed partition device according to claim 2, wherein the first chamber is a combustion chamber and the second chamber is a heat recovery chamber provided with a heat transfer tube. 4. The fluidized-bed partitioning device according to claim 2, wherein the first chamber is a partial combustion chamber and the second chamber is a combustion chamber. 5. The fluidized bed partitioning device according to claim 2, wherein the first chamber is a partial combustion chamber and the second chamber is a combustion / heat recovery chamber provided with a heat transfer tube. 6. The angle (θ3) between a virtual line connecting the upper end of the lower opening of the partition member and the upper end of the partition member of the wind box and the center line of the partition member of the wind box is in the range of 15 to 45 degrees. A partition member is provided in the fluidized bed as described above.
The partition device for the fluidized bed according to any one of 1. 7. The angle (θ3) between a virtual line connecting the upper end of the lower opening of the partition member and the upper end of the partition member of the wind box and the center line of the partition member of the wind box is smaller than 45 degrees, and The angle (θ2) between the virtual line connecting the lower end of the upper opening of the partition member and the upper end of the partition member of the wind box and the center line of the partition member of the wind box is 1
The fluidized-bed partitioning device according to any one of claims 2 to 5, wherein the fluidized-bed is provided with a partitioning member so as to be larger than 0 degree.