JP2001324108A - Discharging apparatus for fluidized medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for discharging fluidized medium which only discharges a fluidized medium, while preventing the flowing-out of a reaction gas from a fluidized bed, and in addition, enables the stable operation of the fluidized bed. SOLUTION: The fluidized medium is moved downward continuously smoothly by gravity in a fluidized medium discharge pipe 6b, by introducing a sealing fluid E to the pipe 6b in an amount such that the medium will not block the pipe 6b or flow in the pipe 6b, while the fluid E is made to flow upward to a fluidized medium lead-out pipe 6a through the pipe 6b. The flow velocity of the fluid E is gradually decreased, by gradually increasing the cross-sectional area of the pipe 6a as going to the upper part from the lower part, so that a material seal which prevents flow-out of the reaction gas from the fluidized bed 5 is formed, by filling up the upper part of the pipe 6a positioned in the fluidized bed 5 with the fluidized medium at a space factor which is nearly equal to that of a close-packed state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluidized medium discharging device for discharging only a fluidized medium while preventing a reaction gas from flowing out of a fluidized bed.

[0002]

2. Description of the Related Art Conventionally, an unreacted gas (or liquid) as an unreacted fluid is introduced into a fluidized bed containing a fluidized medium such as catalyst particles or reactive solid particles to cause the fluidized medium to flow.
Thus, there is known an apparatus which obtains a reactive gas by performing a solid-gas chemical reaction or the like between a fluid medium and an unreacted gas.

[0003] In this apparatus, in order to operate the fluidized bed stably, the fluidized medium in the fluidized bed is fixed, the bed height of the fluidized bed is kept constant, and, for example, residual catalyst particles and reacted solid particles are deteriorated. It is necessary to discharge a fluid medium such as material continuously or as needed from the bottom of the fluidized bed during operation, and to replenish the fluid. At the same time, it is necessary to prevent the reaction gas from flowing out of the fluidized bed.

[0004] As a flowing medium discharge device having such a function, for example, a double damper device is known. This double damper device is provided with openable and closable dampers at two locations in the vertical direction in the middle of a fluid medium discharge pipe extending vertically and having an upper part communicating with the bottom of the fluidized bed. (To open one and close the other, open the other and close one, and repeat this) to discharge only the fluid medium while preventing the reaction gas from flowing out of the fluidized bed. It is.

[0005]

However, in the above-described fluidized medium discharge device, the fluidized medium is basically intermittently discharged, so that the height of the fluidized bed fluctuates between discharge and stop. However, there is a problem that the fluidized bed cannot be operated stably.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it is intended to discharge only a fluid medium while preventing outflow of a reaction gas in a fluidized bed and to perform a stable operation of the fluidized bed. It is an object of the present invention to provide a fluidized medium discharge device that enables it.

[0007]

A fluid medium discharging device according to the present invention is a fluid medium discharging device applied to a device for introducing an unreacted fluid into a fluidized bed containing a fluid medium and flowing the fluid medium. An upper portion is located in the fluidized bed, and a fluid medium outlet pipe having a shape in which a cross-sectional area is sequentially increased from the lower portion to the upper portion, and is connected to a bottom portion of the fluid medium outlet tube and vertically extends, A fluid medium discharge pipe which has the same shape over the entire length, and a lower portion is led out of the fluidized bed,
And an amount of sealing fluid that does not block and fluidize the fluid medium in the fluid medium discharge pipe is introduced into the fluid medium discharge pipe.

[0008] According to such a fluid medium discharge device, an amount of sealing fluid that does not block and fluidize the fluid medium in the fluid medium discharge pipe is introduced into the fluid medium discharge pipe, so that the fluid medium is intermittent. Instead, the sealing fluid moves downward smoothly continuously due to gravity, while the sealing fluid flows upward. When the sealing fluid reaches the fluid medium outlet pipe, the fluid medium outlet pipe has a shape in which the cross-sectional area gradually increases from the lower part to the upper part, so that the flow velocity of the seal fluid decreases. Accordingly, a material seal is formed at the upper portion of the fluidized medium discharge pipe located in the fluidized bed, in which the fluidized medium is filled at a porosity close to the close packing, thereby preventing the reaction gas from flowing out of the fluidized bed.

Here, when the porosity of the fluid medium in the fluid medium discharge pipe is ε, if the sealing fluid is introduced so as to satisfy 0.42 <ε <0.45, it is possible to discharge the fluid medium. The fluid medium does not block the inside of the pipe, and the fluid medium does not fluidize.

[0010] The seal fluid is preferably an inert gas which is not subjected to a reaction.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a fluid medium discharging device according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram showing a desulfurization device to which a fluidized medium discharge device according to the present invention is applied.

As shown in FIG. 1, the desulfurization apparatus 1 introduces a combustion exhaust gas A as an unreacted gas into a fluidized bed 5 formed by activated carbon B as a fluidizing medium, so that Sulfur dioxide (SO ₂ ) is adsorbed on activated carbon B, thereby obtaining desulfurized gas C as a reacted gas. Hereinafter, the desulfurization apparatus 1 will be described in detail.

The desulfurization apparatus 1 includes an apparatus main body 2 in which a fluidized bed 5 is accommodated. This fluidized bed 5 is formed of activated carbon B. The apparatus main body 2 has a cylindrical shape, an inlet 4 for introducing the combustion exhaust gas A at a lower side thereof, an outlet 3 for discharging the desulfurization gas C at an upper portion thereof, and an activated carbon F having sulfur dioxide adsorbed at the bottom thereof. Flowing medium discharge device 6
Each is provided. Further, an air diffusion plate 7 having a large number of air diffusion holes is provided at a lower portion in the apparatus main body 2 in order to make the flow of the introduced combustion exhaust gas A uniform.

The fluid medium discharge device 6 includes an upper fluid medium discharge pipe 6a and a lower fluid medium discharge pipe 6b, and extends vertically.

The fluid medium outlet pipe 6a has a shape whose cross section perpendicular to the axis is circular or rectangular (preferably rectangular, but may be a polygon other than rectangular), and whose cross-sectional area increases gradually from the lower part to the upper part. Then, the whole is located in the apparatus main body 2 and the upper surface of the upper part thereof is arranged at the same level as the diffuser plate 7 in the fluidized bed 5.

The fluid medium discharge pipe 6b extends vertically and has an upper part connected to the bottom of the fluid medium discharge pipe 6a to form the same shape as the bottom of the fluid medium discharge pipe 6a.
It has the same shape (same cross-sectional area) over the entire length, and is configured so as to be entirely led out of the apparatus main body 2.

The fluid medium discharge device 6 further discharges the sealing fluid D into the inside of the fluid medium discharge pipe 6b from a small hole formed at the side of the fluid medium discharge pipe 6b when the activated carbon F adsorbing sulfur dioxide is discharged. It is configured to blow (introduce).

The seal fluid D introduced into the fluid medium discharge pipe 6b is an inert gas not used for the reaction, and in this embodiment, is a nitrogen gas which can be obtained at a low cost. Then, the nitrogen gas D is supplied to the flowing medium discharge pipe 6.
A small amount is introduced into b.

More specifically, an amount (fluidity) that can prevent the activated carbon F having adsorbed sulfur dioxide from blocking the inside of the fluid medium discharge pipe 6b and that does not fluidize the fluid medium discharge pipe 6b. Nitrogen gas D is introduced in an amount not exceeding the minimum gas amount that does not cause fluidization in the medium discharge pipe 6b.

Here, assuming that the porosity of the activated carbon F adsorbing sulfur dioxide in the fluidized medium discharge pipe 6b is ε, the nitrogen gas D is set so that the porosity of the fixed bed <ε <the porosity of the fluidized bed.
Is introduced. Since the porosity of the fixed bed is about 0.4 and the porosity of the fluidized bed is about 0.5, in this embodiment, 0.42 <
Nitrogen gas D is introduced so that ε <0.45.

Next, the operation of the desulfurization apparatus 1 configured as described above will be described. When the combustion exhaust gas A is introduced from the inlet 4, the flow of the combustion exhaust gas A is made uniform by the diffuser plate 7, and the activated carbon B flows and is stirred as shown by the arrow in the figure. At this time, the sulfur dioxide in the combustion exhaust gas A is adsorbed on the activated carbon B, and the reacted gas is discharged from the outlet 3 as the desulfurization gas C. On the other hand, the activated carbon F having adsorbed the sulfur dioxide enters the fluidized medium discharge pipe 6a.

Here, when the activated carbon F adsorbing sulfur dioxide is discharged, the nitrogen gas D is introduced into the fluid medium discharge pipe 6b.
Is blown so as to satisfy the above conditions. Then, the activated carbon F having adsorbed sulfur dioxide in the fluidized medium discharge pipe 6b is not intermittently (problem of the prior art) but moves continuously and smoothly downward by gravity, and is discharged out of the system.

On the other hand, the nitrogen gas E rises in the flowing medium discharge pipe 6b and reaches the flowing medium discharge pipe 6a. Here, as described above, since the fluid medium outlet pipe 6a has a shape in which the cross-sectional area increases gradually from the lower part to the upper part, the superficial velocity of the nitrogen gas E decreases as it goes to the upper part. . Therefore, in the upper part of the fluid medium outlet pipe 6a, the activated carbon F having adsorbed sulfur dioxide is filled at a porosity close to the fine packing, and a fine packing region is formed.

The densely packed region forms a material seal, and the material seal prevents the desulfurization gas C as a reaction gas in the fluidized bed 5 from flowing out.

As described above, in this embodiment, the activated carbon F adsorbing sulfur dioxide moves down the fluid medium discharge pipe 6b continuously and smoothly by gravity, not intermittently, while the fluid medium discharge pipe 6a Since a material seal for preventing the desulfurization gas C from flowing out of the fluidized bed 5 is formed, only the activated carbon F adsorbing sulfur dioxide is discharged while preventing the desulfurization gas C from flowing out of the fluidized bed 5. In addition, stable operation of the fluidized bed 5 is enabled.

As described above, the present invention has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment. Although the fluidized medium discharge pipe 6b is entirely located outside the fluidized bed 5 in the bed 5,
For example, the bottom of the fluid medium discharge pipe 6a may be shortened upward, the upper part of the fluid medium discharge pipe 6b may be lengthened upward, and the upper part of the fluid medium discharge pipe 6b may be located in the fluidized bed 5; Alternatively, the bottom of the fluid medium outlet pipe 6a may be led out of the fluidized bed 5.

Further, in the above embodiment, the desulfurization apparatus for obtaining the desulfurized gas C as the reacted gas by using the unreacted gas as the combustion exhaust gas A and the fluidized medium as the activated carbon B and discharging the activated carbon F adsorbing the sulfur dioxide. Although the application to 1 is described, the unreacted gas is, for example, air, the fluidized medium is, for example, silica sand, and garbage (general waste or industrial waste, etc.) is introduced into the fluidized bed and pyrolysis gasified. The present invention is similarly applicable to a refuse gasifier that obtains combustible gas as a reacted gas and simultaneously discharges ash (so-called bottom ash) with silica sand as a fluid medium. By appropriately selecting the unreacted gas and the fluid medium, the present invention can be applied to various other apparatuses. Therefore, the unreacted fluid A introduced into the fluidized bed 5 is not limited to gas, but may be liquid. Also, the sealing fluid D
Is not limited to gas, but may be liquid.

[0028]

The fluid medium discharge device according to the present invention introduces a sealing fluid into the fluid medium discharge pipe in such an amount that the fluid medium in the fluid medium discharge pipe is not blocked and fluidized.
The fluid medium is moved downward smoothly continuously by gravity, not intermittently, while the sealing fluid is caused to flow upward to reach the fluid medium outlet pipe. By adopting a configuration having a shape in which the cross-sectional area is gradually increased, the flow velocity of the sealing fluid is gradually reduced, and the fluid medium is filled into the upper part of the fluid medium outlet pipe located in the fluidized bed at a porosity close to the close packing. Since it is configured to form a material seal that prevents the outflow of the reaction gas in the fluidized bed, only the fluid medium is discharged while preventing the outflow of the reaction gas in the fluidized bed,
In addition, it is possible to provide a fluidized medium discharge device that enables stable operation of the fluidized bed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a desulfurization device to which a fluidized medium discharge device according to the present invention is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Desulfurization apparatus, 5 ... Fluidized bed, 6 ... Fluid medium discharge apparatus, 6
a: fluid medium outlet pipe, 6b: fluid medium discharge pipe, A: combustion exhaust gas (unreacted fluid), B: activated carbon (fluid medium), D,
E: nitrogen gas (inert gas: seal fluid), F: activated carbon with sulfur dioxide adsorbed.

Claims (3)

[Claims] 1. A fluid medium discharging device applied to a device for introducing an unreacted fluid into a fluidized bed containing a fluidized medium and flowing the fluidized medium, wherein an upper part is located in the fluidized bed, and a lower part is located in the fluidized bed. A fluid medium outlet pipe having a shape in which the cross-sectional area increases in order from the top to the upper part, and the fluid medium outlet pipe is provided at the bottom of the fluid medium outlet pipe, extends vertically, and has the same shape over the entire length, A fluid medium discharge pipe whose lower part is led out of the fluidized bed, and a sealing fluid is introduced into the fluid medium discharge pipe in an amount such that the fluid medium in the fluid medium discharge pipe is not blocked and fluidized. Fluid medium discharge device. 2. The sealing fluid is introduced so as to satisfy 0.42 <ε <0.45 when a porosity of the fluid medium in the fluid medium discharge pipe is ε. Item 6. A fluid medium discharging device according to Item 1. 3. The fluid discharge device according to claim 1, wherein the sealing fluid is an inert gas.