JPH05200272A - Moving bed type reaction tank - Google Patents

Abstract

PURPOSE:To achieve stable operation by dividing a passage of a granular substance into three beds, that is, the first bed between a main louver and a sub-louver, the second bed between the sub-louver and the partition plate on the downstream side of the sub-louver and the main reaction bed being the third bed on the downstream side of the partition plate and independently controlling the flow velocity and flow rate of granular particles flowing down through the respective beds. CONSTITUTION:Louvers are provided on the inlet and outlet sides of gas 6 and the louvers on the gas inlet side are set to main louvers 1 and a sub-louvers 2 each having a triangular cross section are provided inside the louvers 1 in one row in parallel to the louvers 1 in order to prevent the stagnation of a granular substance 7. Further, a partition plate 3 having vent holes is provided inside the sub-louvers 2 in a vertical direction in parallel to the louvers 1, 2. By this constitution, the flow of the substance 7 is divided into the first bed between the louvers 1 and the sub-louvers 2, the second bed between the sub-louvers 2 and the partition plate 3 and the third bed between the partition plate 3 and gas outlet louvers 1' and the flow velocities and flow rates of the substance 7 flowing down through the respective beds can be independently controlled.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a moving bed in which particulate matter such as a carbonaceous adsorbent or a catalyst moves from the top to the bottom.
The present invention relates to a moving bed type reaction tank for passing and contacting Ox and NOx-containing exhaust gas and reaction component-containing gas in a cross-flow to perform adsorption such as dust removal, desulfurization, denitration, or various reactions.

[0002]

2. Description of the Related Art FIG. 2 is a sectional view schematically showing an example of a conventional moving bed reaction tank. Conventionally, in this type of device, as shown in the figure, the particulate matter is filled and held by an inlet side main louver 1 and an outlet side louver 1 ', which are vertically arranged in a line, and is partitioned by a sublouver 2 having a triangular cross section. 7 moves from top to bottom to form a moving bed, and the gas 6 is introduced into the reaction tank 5 from the side of the moving bed through the main louver 1 and penetrates the moving bed, during which dust, reaction, etc. And is discharged from the louver 1'on the outlet side. Such a moving bed reaction tank equipped with a sublouver having a triangular cross section does not generate a non-moving part of the particulate matter on the louver, and further, a moving bed formed between the main louver and the sublouver is used. As a dust removal layer for removing substances that cause pressure drop increase such as dust and adsorptive substances and substances that interfere with the reaction in the main reaction layer such as catalyst poisoning substances, after the sublouver This is a moving bed reaction tank that can be adapted to a wide range of conditions by appropriately controlling the flow rate of the particulate matter in both moving beds with the flow side as the main reaction bed.
In this case, the flow velocity of the particulate matter flowing down in the moving bed should be high enough to sufficiently remove the dusts in the gas in the dust removal layer, and the utilization efficiency of the particulate matter should be high in the main reaction layer. It is desirable to make it as late as possible.

[0003]

However, even if the reaction tank having such a structure is used, if the dust concentration in the supplied gas becomes high, the dust cannot be completely removed in the dust removing layer. In some cases, the leaked dust accumulates on the sub-louver side of the main reaction layer having a slow moving speed, which causes an increase in pressure loss, which hinders the operation of the device. Further, if the distance between the main louvers is increased in accordance with the enlargement of the apparatus and the increase in the gas amount, the distance between the point B of the louver AB and the next louver becomes too large as shown in FIG. The flow of particulate matter in the vicinity deteriorates, and dust and reaction products tend to accumulate. Therefore, even if the device grows in size, the size of the main louver and sub louver cannot be increased, and the layer thickness of the particulate matter between the main louver and sub louver is insufficient, and sufficient dust removal is possible. In addition, because the distance between the sub-louvers is narrow for the gas flow rate, the linear velocity of the gas increases and the dust that has once been trapped is blown off to the subsequent stage. There was a problem that dust was accumulated and pressure loss increased in the latter stage where the speed was low.

An object of the present invention is to solve the above problems and provide a moving bed type reaction tank suitable for a large-scale apparatus and applicable to a gas having a high dust concentration.

[0005]

According to the present invention, a particulate matter is filled and held by a breathable structure, and the particulate matter is moved from top to bottom to form a moving layer. In a moving bed type reaction tank that comes into contact with the passing gas, the gas inlet side and the gas outlet side are supported by louvers, and the louver on the gas inlet side serves as the main louver, and the retention of particulate matter inside the main louver is prevented. In order to do so, sub louvers with a triangular cross section are provided in a row in parallel with the main louver, and a partition plate having ventilation holes inside the sub louver is provided in the vertical direction in parallel with the main louver and the sub louver. According to the configuration, the flow of the particulate matter is divided into the first layer between the main louver and the sublouver, the second layer between the sublouver and the partition plate, and the partition plate and the gas outlet side valve. Divided into a third layer between the bars, which is a moving bed type reaction vessel, characterized in that as the flow velocity and flow rate of the particulate material flowing down the respective layers can be controlled independently.

Here, the important feature of the present invention is that the flow of the particulate matter is caused by the first layer (U _{1 in} FIGS. 5 and 6) between the main louver and the sublouver, and between the sublouver and the partition plate. The second layer (also U ₂ ), and the third layer (also U ₃ ) between the partition plate and the gas outlet side louver are divided into three parts, and the respective flows are separately controlled, whereby a moving bed type reaction tank The point is that it enables efficient operation. In order to further facilitate the control of these flows, it is preferable to be able to adjust the amount and flow rate of the particulate matter flowing in each flow path.
That is, as shown in FIGS. 1 and 4, a partition plate is provided along the inner wall of the casing 8 of the moving bed type reaction tank from the lower end of the lowermost sublouver or the lower end of the flow path adjusting plate and the lower end of the partition plate. 9 and 11 are provided, and the partition plate is continuous to the inside of the particulate matter discharge nozzle of the moving bed type reaction tank. At the ends of the partition plates 9 and 11, rotary partition plates 10 and 12 having an axis parallel to the end sides are provided, and the angles of the rotary partition plates 10 and 12 are externally changeable. By changing the angle of the rotary partition plate, the moving velocity distribution of the particulate matter in the tank can be made effective without increasing the total amount of extraction.

The shape, size or installation position of the main louver 1, the sub louver 2, the partition plate 3, and the flow path adjusting plate 4, and the flow rate and flow velocity of the particulate matter in the flow of particulate matter U ₁ , U ₂ and U ₃ . And the like may be arbitrarily set within the above range depending on the amount of the processing gas and the amount of substances such as dust and depositable substances that cause an increase in pressure loss. In this case, the distance between the main louver and the sub louver cannot be made very large, so dust and the like that could not be sufficiently removed by the particulate matter flowing between U ₁ of U ₂ provided on the downstream side of the sub louver. Try to remove more in parts. The distance between the sub bar and the partition plate can be set in a relatively wide range according to the amount of dust and the like. Thus, U ₁ and U ₂ provided on the gas inlet side of the reaction tank
The gas, from which dust and catalyst poisoning substances have been almost completely removed by the particulate matter flow, is not affected by dust and catalyst poisoning substances in U ₃ which is the main part of the particulate matter. A main reaction such as a denitration reaction can be performed.
The moving bed type reaction tank of the present invention treats an exhaust gas containing a large amount of dust, and carries out a plurality of treatments in one reactor as in the case of performing desulfurization denitration or denitration together with dedusting, a reaction for performing a reaction. It is particularly suitable as a tank.

The moving bed type reaction tank of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view of an apparatus showing one embodiment of the moving bed type reaction tank of the present invention, and FIG. 4 is a sectional view of an apparatus showing another embodiment of the moving bed type reaction tank of the present invention. .. The apparatus of FIG. 1 has a main louver of a usual structure, but the reaction tank of FIG. 4 has a large pitch between the louvers in order to process a large amount of gas. In the apparatus of FIG. 4, in order to improve the flow of particles in the vicinity of the main louver with a large pitch, the shape of the main louver 1 is made to have a polygonal line ABCD as shown in FIG. In the normal louver structure as shown in FIG. 3, if the length of AB is increased, the distance between the point B and the next louver AB becomes too large, and the flow of particles near the point X deteriorates. For this reason, both ends of the louver EH are made substantially vertical like EF and GH, and the overall shape of the main louver is made to have a polygonal cross section, whereby the particulate matter between the main louver and the sub louver is prevented. The width of the flow path is made substantially uniform. The size of the main louver 1 having a polygonal cross section in FIG. 7 is such that the ratio of a, b and c is about 3 to 5: 4.
It is preferably in the range of 6: 1 and the angle θ is preferably in the range of 65 ° to 75.

As shown in FIGS. 5 and 6, the sub-louver 2 has a vertex C at one end, and one side CD whose one end is C extends downward from the vertex C toward the main louver D. And the other side CE is inclined downward from the vertex C vertically or within 5 °, preferably within 3 °, toward the inside of the moving layer. The reason that the side CE is inclined inward is to prevent the particulate matter flowing down between the main louver and the sub louver from leaking into the inside of the moving layer. When provided, it need not be tilted. This sub-louver is installed so that the apex D is approximately in the middle between the lower end B of the main louver and the lower end B of the next main louver in the device of FIG. 1, and in the device of FIG. The apex D is installed so as to be substantially in the middle between the lower end GH of the main louver and the lower end GH of the next main louver. If the apex D is too close to the left, the width of the flow path of the particulate matter between the main louver and the sub louver will be uneven, and an extremely narrow portion will be generated. No effect.
The shape of the sub-louver is preferably such that the flow velocity of the particulate matter flowing near the sub-louver is slightly higher than the flow velocity near the main louver. This shape is appropriately determined based on the size of the device, the size of the particulate matter, etc., but the angle DCE should be 30 ° to 55 °, and the side D
It is preferable that the inclination and length of E become wider within the range where the angle CED is 25 ° to 35 ° as the flow path formed by the main louver and the side DE goes downward. If the distance between the sub-louver and the sub-louver becomes too large, the particulate matter flowing on both sides of the sub-louver may be mixed with each other, so ventilation is performed between the lower end E of the upper sub-louver and the upper end C of the lower sub-louver. The flow path adjusting plate 4 having the property is provided to prevent the mixture of both. This flow path adjusting plate may be constituted by a porous plate having a large number of holes on the entire surface of the plate or a slit plate in which elongated plates are arranged at regular intervals.

In the present invention, a partition plate 3 having ventilation holes on the downstream side of the sublouver is provided in the vertical direction in parallel with the sublouver and an independent flow of particulate matter is provided between the sublouver and the partition plate. Form a path. This partition board is required to meet the following three requirements. First of all, it must have sufficient breathability. Secondly, the rate at which the particulate matter flowing down on both sides of the partition plate mixes with each other is as small as possible, and the leakage from one to the other is 1%.
The following is preferable. Thirdly, it has strength to withstand the powder pressure of the particulate matter from both sides and the friction caused by the flowing particulate matter. As a structure that satisfies these requirements, a perforated plate (punching plate) that has a large number of holes on the entire surface of the plate and appropriately uses a reinforcing material, or a slit plate or a flat bar in which elongated plates are arranged at regular intervals. A formal structure having an aperture ratio of 30% or more is preferably used. The gas outlet louver of this reaction tank is not limited in shape and the like as long as it has sufficient air permeability and can support the particulate matter, and may be a perforated plate in addition to the usual louver structure. With such a configuration, the flow of the particulate matter inside the moving bed reaction tank is divided into three of U ₁ , U ₂ and U ₃ in FIGS. 5 and 6, and each flow is controlled separately, It enables efficient operation of the moving bed reactor.

In the example in which the moving bed type reaction tank of the present invention shown in FIG. 1 or 4 is applied to a dry desulfurization and denitration apparatus, the gas inlet side is held by the main louver 1, and the main louver is installed between the main louver and the sublouver. A first dedusting / desulfurizing zone, and a second dedusting / desulfurizing zone between the partition plate 3 and the sublouver provided on the downstream side of the sublouver. Use as denitration zone. Exhaust gas containing dust and SOx and NOx is first subjected to dedusting and desulfurization through the first dedusting / desulfurization zone, and then dust and SOx that cannot be removed in the first zone in the second dedusting / desulfurization zone. Be sure to remove it sufficiently. The gas that has passed through the first and second dedusting / desulfurization zones contains almost no dust or SOx that causes pressure loss or catalyst poisoning. Therefore, in the denitration zone, the flow rate of activated coke should be slowed down. The use efficiency of the activated coke can be sufficiently increased. That is,
The flow of active coke in the moving bed can be divided into three, and the flow rate and flow velocity of active coke in each part can be arbitrarily adjusted according to the amount of processing gas and the concentration of dust, SOx, NOx, etc. contained. , Extremely efficient operation becomes possible.

[0012]

【Example】

(Example 1) In the apparatus shown in FIG. 1, activated coke 7 having an average particle size of about 8 mm was supplied into the reaction tank from a hopper 16 provided above the reaction tank in the direction of the arrow, and the inside of the reaction tank was moved downward from above. And is withdrawn from the lower part of the reaction tank.
On the other hand, the gas 6 to be treated is supplied from the side surface of the reaction tank through the gas inlet side main louver 1 into the moving bed according to the arrow, and desulfurization, denitration and dust removal are carried out through the active coke layer, and the gas on the other side surface. It is discharged from the outlet louver 1 '. The active coke in the reaction tank is held by the main louver 1 on the inlet side and the louver 1'on the outlet side. On the inlet side, next to the main louver 1, a sub-louher 2 in which a flow path adjusting plate 4 is arranged, a partition plate 3 is arranged on the downstream side, and a partition plate extending below the flow path adjusting plate and the partition plate in the lowermost stage. It is composed of plates 9 and 11, and further rotating partition plates 10 and 12 that follow therebelow. The flow rate of the whole active coke is controlled by the quantitative feeder 15. Further, a rectifying body 13 is provided at the bottom of the mainstream layer of the activated coke, and the moving speed of the activated coke is controlled by measuring the descending speed of the activated coke from 14 sight glasses. FIG. 5 is a detailed view of the louver portion on the entrance side. In the device used in this example, the size of the opening of the main louver,
That is, the distance between B and B is 450 mm, the distance between the main louver and the sub louver (a in FIG. 5) and the distance between the sub louver and the partition plate (b in FIG. 5) are 100 mm and 300 mm, respectively. The thickness of the third layer on the flow side is 1
It was 400 mm. The side CE of the sub bar is vertical,
The length of CE was 350 mm, the distance between the sub-louvers, that is, the distance between point E in FIG. 5 and point C below was 70 mm, and a structure in which a CE plate was connected with a multiplicity of apertures was used between them.
The partition plate has a flat bar structure in which plates having a width of 100 mm are arranged horizontally at intervals of 100 mm, and the exit side louver 1'is replaced by a perforated plate. Using this device,
And the flow rate and residence time of the three layers of desulfurized denitration molded activated coke were 334 mm / hr and 32 hr, respectively.
34 mm / hr and 80 hr and 57 mm / hr and 188
200 mg / Nm ³ D.h. B. Dust, S
A treatment test of a gas containing 50 ppm of Ox and 250 ppm of NOx was conducted. As a result, the total pressure loss was about 100 mmAq at the start of the operation and gradually increased with the passage of time, but after 72 hours, it was about 150 mmAq, which was almost constant, and stable operation was possible.

On the other hand, the same apparatus was used except that the partition plate 3 was not provided, and the flow rate and the residence time of the first and second layers of desulfurized and denitrated molded active coke were 44 and 40, respectively.
0 mm / hr and 25 hr and 63 mm / hr and 171 h
When a similar test was carried out for r, the pressure loss, which was about 100 mmAq at the start of operation, gradually increased and exceeded 250 mmAq in about 72 hours, making it difficult to continue operation.

Example 2 In FIG. 4, the average particle size is 8 m.
About m of activated coke is supplied according to arrow 7 from a hopper (not shown) provided above the reaction tank into the reaction tank,
It moves from the upper part to the lower part in the reaction tank and is withdrawn from the lower part of the reaction tank. On the other hand, the gas to be treated enters from the side surface of the reaction tank according to arrow 6, passes through the louver and the activated coke layer, undergoes desulfurization, denitration and dust removal, and is discharged from the opposite side surface.
The active coke in the reaction tank is held by the main louver 1 on the inlet side and the louver 1'on the outlet side. On the inlet side, next to the main louver 1, a sub-louher 2 in which a flow path adjusting plate 4 is arranged, a partition plate 3 is arranged on the downstream side, and a partition plate extending below the flow path adjusting plate and the partition plate in the lowermost stage. Plates 9 and 11, and a rotary partition plate 1 further below
It consists of 0 and 12. Further, a rectifying body 13 is provided at the bottom of the mainstream layer of the activated coke, and the moving speed of the activated coke is controlled by measuring the descending speed of the activated coke from 14 sight glasses.

FIG. 7 is a detailed view of the louver portion on the inlet side.
Here, θ is 70 °, α is 40 °, β is 30 °, and a is 4
30mm, b is 470mm, c is 100mm, d is 17
6 mm, e is 684 mm, f is 140 mm, g is 200
mm and h are 300 mm, the long side of the sub-louver is vertical, and although not shown, the thickness of the mainstream layer of the activated coke on the downstream side of the partition plate 3 is 1300 mm. / Nm ³ D. B. , SOx
A gas treatment test of 50 ppm and NOx 250 ppm was conducted. As a result, the flow of the activated coke in the first dedusting / desulfurization zone does not smoothly generate a retention portion, and the activated coke with dust or SOx components does not leak to the denitration zone, and the active coke in each zone does not leak. By appropriately adjusting the flow rate of 1, the smooth operation was possible with a desulfurization rate of 100%, a denitration rate of 80%, and a dust removal rate of 95% or more.

[0016]

In the moving bed reaction tank of the present invention, a partition plate is installed on the downstream side of the sublouver, and the flow path of the particulate matter is the first layer between the main louver and the sublouver. The flow velocity and flow rate of the particulate matter flowing down into each of the two layers are divided into the main reaction layer, which is the second layer between the partition plate of the subsequent flow and the third layer of the downstream flow of the partition plate. It is configured so that it can be controlled. Therefore, even when treating a gas containing a large amount of a substance that causes an increase in dust amount or pressure loss, the dust and the pressure loss increasing substance can be sufficiently removed in the first and second layers, so that the pressure loss as a whole is reduced. Since the rise of is kept constant within a small range, stable operation of the device is possible. Further, since a sufficient effect can be obtained only by providing the partition plate in the reaction tank having the conventional structure, there is an advantage that a large-scale apparatus modification such as changing the structure of the main louver portion is not required. Furthermore, by making the structure of the main louver a broken line in cross section, the pitch between the louvers can be made significantly larger than that of the louvers of the conventional structure, and the size of the device can be increased.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an apparatus showing one embodiment of a moving bed type reaction tank of the present invention.

FIG. 2 is a sectional view showing an outline of an example of a conventional moving bed type reaction tank.

FIG. 3 is a louver vicinity view of the moving bed type reaction tank of FIG.

FIG. 4 is a cross-sectional view of an apparatus showing another embodiment of the moving bed type reaction tank of the present invention.

FIG. 5 is a detailed explanatory view of a main louver, a sub louver, a flow path adjusting plate and a partition plate of the present invention.

FIG. 6 is a diagram illustrating the positions and structures of a main louver, a sub louver, a flow path adjusting plate and a partition plate of the present invention.

FIG. 7 is a diagram illustrating in detail the angles and positions of the main louver, the sub louver, the flow path adjusting plate, and the partition plate of the present invention.

[Explanation of symbols]

 1. Main louver 1 '. Exit louver 2. Subroubar 3. Partition plate 4. Flow path adjusting plate 5. Reaction tank 6. Gas 7. Particulate matter 8. Casing 9,11. Partition plate 10, 12. Rotating partition plate 13. Rectifier 14. Sight glass 15. Quantitative feeder 16. hopper

Claims (3)

[Claims] 1. A movement in which a particulate matter is filled and held by a breathable structure, the particulate matter is moved from top to bottom to form a transfer layer, and is brought into contact with a gas passing through the breathable structure from the lateral direction. In the layered reaction tank, the gas inlet side and the gas outlet side are supported by louvers, the louver on the gas inlet side is used as the main louver, and in order to prevent the accumulation of particulate matter inside the main louver, a subsection with a triangular cross section is used. The louvers are provided in a line in parallel with the main louver, and a partition plate having a vent hole inside the sub louvers is provided in the vertical direction in parallel with the main louvers and the sub louvers. The flow is divided into a first layer between the main louver and the sublouver, a second layer between the sublouver and the partition plate, and a third layer between the partition plate and the gas outlet side louver. A moving bed type reaction tank characterized in that the flow rate and flow rate of the particulate matter flowing down in each layer can be controlled independently. 2. The moving bed type reaction tank according to claim 1, wherein the main louvers have a linear shape in cross section and are arranged in a line in the vertical direction. 3. A partition plate is provided along the inner wall of the casing of the moving bed type reaction tank from the lower end of the lowermost sublouver or the lower end of the flow path adjusting plate and the lower end of the partition plate that are continuously provided below the sublouver. The transfer according to claim 1 or 2, wherein the partition plate is continued to the inside of the particulate matter discharge nozzle of the moving bed type reaction tank so that the flow rate of the particulate matter flowing through the first to third layers can be adjusted. Layered reaction tank.