JP3351658B2 - Dry desulfurization / denitration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry desulfurization / denitration apparatus capable of simultaneously performing desulfurization and denitration in a reaction tower.

[0002]

2. Description of the Related Art Conventionally, in a dry desulfurization / denitration apparatus,
A catalyst such as activated carbon is moved from the upper end to the lower end of the reaction tower, and desulfurization and denitration are simultaneously performed by passing a gas to be treated therebetween, and sulfur oxides such as sulfurous acid gas (SO ₂ ) and nitrogen oxides ( NO _x ) is removed.

FIG. 2 is a perspective view of a conventional reaction tower, FIG. 3 is a cross-sectional view of the conventional reaction tower, and FIG. 4 is a diagram showing a measurement result of a conventional particle size distribution. In the drawing, reference numeral 11 denotes a reaction tower main body in which a pair of moving layers 10 parallel to each other is formed, and an upper hopper 12 having a pyramid (cone) shape, and the upper hopper 1
2, a body 13 having a rectangular cross section connected to the body 2;
3 is connected to a lower hopper 14 having a pyramid shape. The upper hopper 12 has a supply port 15 at the upper end.
The lower hopper 14 has a discharge port 16 at the lower end, and the catalyst 17 dropped from the supply port 15
It moves downward in the moving bed 10 and the lower hopper 14 and is discharged to the outside through the discharge port 16. Further, the outlet 16
The catalyst 17 discharged from is regenerated by a regenerator (not shown) and supplied to the supply port 15 again.

A gas supply section 18 for supplying a gas to be treated is provided on one of the side walls of the body 13, and a gas discharge section 20 for supplying a gas to be treated is provided on the other side of the side wall. Is established. Further, in the body 13, the gas to be processed supplied from the gas to be processed supply section 18 is diverted to the left and right, moves in each moving layer 10, and flows into the gas to be processed discharge section 20.
Is discharged from

The moving bed 10 is provided with an entrance louver 1.
0a and an outlet louver 10b. The entrance louver 1
Reference numeral 0a has an opening structure so that the medium 17 does not drop, and the outlet louver 10b is formed of a perforated plate so that the gas to be processed can be passed. The diameter of each hole of the perforated plate of the outlet louver 10b is set smaller than the particle diameter of the catalyst 17, so that the catalyst 17 does not flow out of the inlet louver 10a and the outlet louver 10b to the outside.

The lower end of the moving bed 10, that is, between the body 13 and the lower hopper 14, is rotated by a drive system (not shown), and is adjusted from the discharge port 16 while constantly adjusting the level of the moving bed 10. A cut-out device 22 for discharging the catalyst 17 by a fixed amount is provided. Therefore, the catalyst 17 in the moving bed 10 moves downward at a constant speed, contacts the gas to be treated during that time, and simultaneously performs desulfurization and denitration.

Incidentally, the catalyst 17 is provided in the reaction tower main body 11.
Of the catalyst 17 having a predetermined angle of repose θ at the upper end of the moving bed 10. When the width of the body 13 is L and the height of the peak of the catalyst 17 formed in the upper hopper 12 is H, the angle of repose θ is θ = tan ⁻¹ {H / (L / 2)}. Can be represented by

[0008]

However, in the conventional dry desulfurization / denitration apparatus, when activated carbon is used as the catalyst 17, it has a wide particle size distribution as shown in FIG. When the peak of the catalyst 17 having a predetermined angle of repose θ is formed because the peak is not uniform, the catalyst 17 having a large particle diameter falls along the slope and gathers in the peripheral portion in the width L direction of the moving bed 10, Small particle size catalyst 17
Gather in the center of the moving layer 10 in the width L direction.

Therefore, similarly in the moving bed 10, the catalyst 17 having a large particle diameter gathers at the peripheral portion in the width L direction of the moving bed 10, and the catalyst 17 having a small particle diameter moves in the width L direction of the moving bed 10. Gather in the central part of. In this case, the gas to be processed easily flows to the peripheral portion in the moving bed 10 and hardly flows to the central portion, and gas drift occurs, so that the denitration rate decreases. An object of the present invention is to solve the problems of the conventional dry desulfurization / denitration apparatus and to provide a dry desulfurization / denitration apparatus capable of increasing the denitration rate without generating gas drift. .

[0010]

For this purpose, in the dry desulfurization / denitration apparatus of the present invention, a catalyst inlet is provided on the upper wall,
An upper distribution hopper having a lower inverted conical portion having an inverted conical shape formed on a lower wall, and a body having a rectangular cross-section, which is divided into compartments by a partition plate. A pair of moving layers for passing the processing gas, an upper hopper provided at a top end of each moving layer, and having a plurality of hopper chambers formed in correspondence with the respective compartments, and It has a chute inlet formed at a plurality of locations on the same circle at a constant pitch and a chute connecting the hopper chambers. Then, the catalyst is dropped from the catalyst inlet to a central portion in the upper distribution hopper, forms a mountain having a predetermined angle of repose in a columnar portion in the upper distribution hopper, and is the same in the circumferential direction. They gather in a particle size distribution and are sent into each of the chutes from the lower inverted cone below the cylindrical portion.

[0011]

According to the present invention, as described above, in the dry desulfurization / denitration apparatus, an upper distribution hopper having a catalyst inlet on an upper wall and a lower inverted conical portion having an inverted conical shape formed on a lower wall; A pair of moving layers formed in the body having a rectangular cross section, divided into compartments by a partition plate, for moving the catalyst downward, and passing the gas to be treated, and disposed at an upper end of each of the moving layers. An upper hopper provided with a plurality of hopper chambers formed corresponding to the respective compartments; a chute inlet formed at a plurality of locations on the same circle in the lower inverted conical portion at a constant pitch; and the hopper chambers And a chute for connecting Then, the catalyst is dropped from the catalyst inlet to a central portion in the upper distribution hopper, forms a mountain having a predetermined angle of repose in a columnar portion in the upper distribution hopper, and is the same in the circumferential direction. They gather in a particle size distribution and are sent into each of the chutes from the lower inverted cone below the cylindrical portion.

In this case, the catalyst supplied to the upper distribution hopper from the catalyst inlet falls to the center of the upper distribution hopper, and forms a mountain having a predetermined angle of repose in a cylindrical portion of the upper distribution hopper. Then, the catalyst having a large particle diameter falls along the slope of the mountain and gathers at the periphery of the upper distribution hopper, and the catalyst having a small particle diameter gathers at the center of the upper distribution hopper. Then, the catalyst in the upper distribution hopper is supplied to each hopper chamber of the upper hopper through each chute from a chute inlet formed at a constant pitch in a lower inverted cone portion below the columnar portion, and Each compartment can be moved downward. Further, the gas to be treated is supplied to the moving bed and brought into contact with a catalyst, and is desulfurized and denitrated by the catalyst.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic view of a dry desulfurization / denitration apparatus according to an embodiment of the present invention, and FIG. 5 is a plan view of the dry desulfurization / denitration apparatus according to the embodiment of the present invention. In the figure, 31 is a reaction tower main body, 35 is a catalyst supply conveyor, and the catalyst 1 conveyed by the catalyst supply conveyor 35.
7 falls into the upper distribution hopper 36.

The upper distribution hopper 36 has a diameter of about 3 mm.
A lower inverted conical portion 38 having a column shape of [m], a catalyst inlet 37 on the upper wall, and an inverted conical shape with an angle of 45 [°] is formed on the lower wall. The lower inverted conical portion 38
The chute inlets 39 are formed at 16 places on the same circle having a radius of 1 [m]. One purge hole 40 is formed at the lowermost portion of the lower inverted conical portion 38, and a purge pipe 41 is connected to the purge hole 40.

Each of the pair of moving layers 55 has upper hoppers 42 and 43 at its upper end, respectively.
Reference numeral 43 denotes eight pyramid-shaped hopper chambers 45 each. Then, each chute inlet 39 and each hopper chamber 45
Are connected by a chute 47 made of an iron pipe having a diameter of 250 [mm]. The upper hoppers 42, 4
Below the 3, there are disposed body portions 48 each having a rectangular cross section, and the moving layer 55 is formed in each body portion 48. Each of the moving layers 55 is partitioned by seven partition plates 49, and eight partition chambers 50 corresponding to the hopper chambers 45 are formed.

A pyramid-shaped lower hopper (not shown) is connected to the lower part of the body 48 similarly to the conventional dry desulfurization and denitration apparatus, and a cutting device and a discharge port are arranged in the lower hopper. You. A processing gas supply chamber 61 is provided between the moving layers 55, and a pair of processing gas discharge chambers 62 and 63 are provided outside the moving layer 55, respectively. A processing gas inlet 65 is connected to the processing gas outlets 62 and 63 to the processing gas discharge chambers 62 and 63, respectively.

Accordingly, the gas to be processed supplied from the gas inlet 65 to be processed is diverted right and left (up and down in FIG. 5) in the gas supply chamber 61 and passes through each moving layer 55 to discharge the gas to be processed. The gas reaches the chambers 62 and 63 and is discharged from the gas outlets 66 and 67. In the dry desulfurization / denitration apparatus having the above configuration, the catalyst 17 transported by the catalyst supply conveyor 35 is supplied to the upper distribution hopper 36.
At this time, the catalyst 17 falls to the central portion in the upper distribution hopper 36, and the catalyst 17 having a large particle size falls along the slope of the mountain and gathers at the peripheral portion of the upper distribution hopper 36, where The small catalysts 17 gather in the center of the upper distribution hopper 36, but in the circumferential direction gather with the same particle size distribution. Therefore, catalysts 17 having the same particle size
7 and is supplied to each hopper chamber 45 of the upper hoppers 42 and 43.

The catalyst 17 in each hopper chamber 45 is
Each gas is supplied to each of the compartments 50 and falls downward in the compartments 50. During this time, the gas comes into contact with the gas to be treated supplied from the gas to be treated supply chamber 61 in a cross flow, and the sulfurous acid gas in the gas to be treated is adsorbed. At the same time, the nitrogen oxides are decomposed into harmless nitrogen (N ₂ ) and water (H ₂ O). Incidentally, the inner diameter of said upper distributing hopper 36 and D _1, the chute inlet 39
The diameter of a circle passing through the center of the hopper is D ₂ , the diameter of the chute 47 is D ₃ , the number of divisions of the upper hoppers 42 and 43, that is, the number of hopper chambers 45 in each of the upper hoppers 42 and 43 is n, Assuming that the pitch between the inlets 39 is P, the relationship is D ₂ = (2n × D ₃ + 2n × P) / π.

When D ₂ / D ₁ = 2/3 and the diameter of the catalyst 17 is D ₄ , the diameter D ₃ of each chute 47 is D ₃ = K ₁ × D ₄ (K ₁ : 10-30). Usually, D ₄ = 10 [mm] n = 8 to 12 P = 50 to 100 [mm], so D ₁ = 2 to 3 [m] D ₂ = about 1.3 to 2 [m] It is preferred that

The height of the upper distribution hopper 36 is H,
Over from the wall to the top of the mountain of the catalyst 17 which is formed in the upper dispensing hopper 36 height of the upper distribution hopper 36 and h _1,
From the top of the mountain to the mountain at the foot of the (foot) height and h _2,
The height from the foot of the mountain to the lower wall of the upper distribution hopper 36 is h ₃
When, becomes _{H = h 1 + h 2 +} h 3, is substantially _{h 1 = h 2 = h 3} .

Further, the angle of repose of the mountain theta catalyst 17, theta = tan becomes ^{_{-1 {h 2 / (D 1}} /2)}, usually about 35 [°]. Assuming that the inclination angle of the portion where each chute 47 is connected to each of the upper hoppers 42 and 43 is θ ₁ to θ ₈ , the inclination angles θ _{1 to} θ ₈ are θ ₁ = θ ₈ <θ ₂ = θ _7. It is set so that <θ ₃ = θ ₆ <θ ₄ = θ ₅ . Normally, the inclination angle θ ₁ is 45
[°] or more is preferable. Further, each moving layer 55
Is L, and the length of the bottom of each hopper chamber 45 is L _{1 to} L
And _8, and the height of each hopper chamber 45 and _{h 4, L = K 2 ×} L 1 (K 2: 4~10) L 1 = L 2 = L 3 = L 4 = L 5 = L
₆ = a L ₇ = L _8, pyramid angle [theta] & apos each hopper chamber 45 can be expressed by _{^{θ'= tan -1 {h 4 /}} (L 1/2)}, edge (Ryo) square Is preferably 40 [°].

The thickness w ₁ of the moving layer 55 depends on the denitration ratio, and is preferably set to w ₁ = 1 to 2 [m].
₂ is w ₂ = K ₃ w ₁ (K ₃ : 1 to 3).

In this embodiment, 0.6 <L ₁ / w ₁ ≦ 1.0. Next, the difference in particle size distribution between the conventional dry desulfurization / denitration apparatus and the dry desulfurization / denitration apparatus of the present invention will be described.

FIG. 6 is a diagram showing a particle size distribution in a conventional dry desulfurization / denitration device, and FIG. 7 is a diagram showing a particle size distribution of a dry desulfurization / denitration device in an embodiment of the present invention. In the figure, the horizontal axis represents the entire catalyst 17 (FIG. 1) and each compartment (in the present invention, compartment 50) # 1 to # 8, and the vertical axis represents the particle size distribution. In this case, the particle size distribution of the catalyst 17 supplied to each of the compartments # 1 to # 8 is shown.

As can be seen from FIG. 6, the conventional dry desulfurization
In the denitration apparatus, the catalyst 17 having a large particle size is provided in the moving bed 1.
0 (FIG. 3) in the width L direction.
8 and the catalyst 17 having a small particle size is formed in the width L of the moving bed 10.
It gathers in the compartments # 4 and # 5 at the center in the direction. In this case, the standard deviation σ indicating the variation of the particle size is 1
4.74.

On the other hand, as can be seen from FIG. 7, in the dry desulfurization / denitration apparatus according to the present invention, both the catalyst 17 having a large particle size and the catalyst 17 having a small particle size have the same size in the width L direction of the moving bed 55. Is supplied uniformly. In this case, the standard deviation σ is 2.99. Next, the relationship between the denitration rate, the space velocity, and the particle diameter in this embodiment will be described. FIG. 8 is a diagram showing the relationship between the denitration rate, the space velocity, and the particle size in the example of the present invention. In the figure, the horizontal axis represents the space velocity sv, and the vertical axis represents the denitration rate.

Here, the space velocity sv is a value obtained by dividing the amount of the gas to be treated by the amount of the catalyst 17 (FIG. 1).
The amount of the gas to be treated that can be treated by a certain amount of the catalyst 17 is shown. As shown in the figure, when the space velocity sv decreases, the denitration rate increases, and as the particle size decreases, the denitration rate increases.

As described above, since the particle size distribution becomes uniform in the width L direction of the moving layer 55, no drift occurs in the gas to be processed. Therefore, the space velocity sv can be uniformly reduced, and the denitration rate can be increased. FIG. 9 is a diagram showing a comparison between the conventional dry desulfurization / denitration device and the dry desulfurization / denitration device of the present invention for the denitration rate of each compartment, and FIG. 10 is a diagram showing the space velocity of each compartment.
It is the figure which compared the conventional dry desulfurization and denitration apparatus with the dry desulfurization and denitration apparatus of the present invention. In FIG. 9, the compartments # 1 to # 8 are plotted on the horizontal axis, the denitration rate is plotted on the vertical axis, and the compartments # 1 to # 8 are plotted on the horizontal axis and the space velocity is plotted on the vertical axis in FIG. .

As can be seen from the figure, the dry desulfurization of the present invention
In the denitration apparatus, since both the denitration rate and the space velocity sv can have an average value in each of the compartments # 1 to # 8, the denitration rate of the entire dry desulfurization / denitration apparatus is about 1.2 [% ] Can be increased. In this embodiment, the reaction tower body 31 (FIG. 1) of the dry desulfurization / denitration apparatus is described, but the present invention can be applied to a catalyst supply tank, a desorption tower, and the like.

As the catalyst 17, other than activated carbon, a general catalyst such as a metal-based denitration catalyst can be used. It should be noted that the present invention is not limited to the above-described embodiments, but can be variously modified based on the gist of the present invention, and they are not excluded from the scope of the present invention.

[0031]

As described above in detail, according to the present invention, in a dry desulfurization / denitration apparatus, a catalyst inlet is provided on an upper wall, and a lower inverted conical portion having an inverted conical shape is formed on a lower wall. And a pair of moving layers formed in a body having a rectangular cross section, divided into compartments by a partition plate, for moving the catalyst downward, and for passing the gas to be treated, and An upper hopper provided at the upper end of the layer and having a plurality of hopper chambers formed so as to correspond to the compartments, and chutes formed at a constant pitch at a plurality of locations on the same circle in the lower inverted conical portion A chute connecting the inlet with each of the hopper chambers; Then, the catalyst is dropped from the catalyst inlet to a central portion in the upper distribution hopper, forms a mountain having a predetermined angle of repose in a columnar portion in the upper distribution hopper, and is the same in the circumferential direction. They gather in a particle size distribution and are sent into each of the chutes from the lower inverted cone below the cylindrical portion.

In this case, the catalyst supplied from the catalyst inlet to the upper distribution hopper forms a mountain having a predetermined angle of repose in a cylindrical portion in the upper distribution hopper. At this time, the catalyst having a large particle diameter falls along the slope of the mountain and gathers at the periphery of the upper distribution hopper, and the catalyst having a small particle diameter gathers at the center of the upper distribution hopper, but in the circumferential direction, Gather with the same particle size distribution. Therefore, the catalyst having the same particle diameter is supplied from the lower inverted conical portion below the columnar portion to each hopper chamber of the upper hopper through each chute.

As a result, the gas to be treated does not generate a drift in the moving bed, so that the space velocity can be reduced uniformly and the denitration rate can be increased.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a dry desulfurization / denitration apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view of a conventional reaction tower.

FIG. 3 is a sectional view of a conventional reaction tower.

FIG. 4 is a diagram showing a measurement result of a conventional particle size distribution.

FIG. 5 is a plan view of the dry desulfurization / denitration apparatus according to the embodiment of the present invention.

FIG. 6 is a diagram showing a particle size distribution in a conventional dry desulfurization / denitration apparatus.

FIG. 7 is a diagram showing a particle size distribution of a dry desulfurization / denitration apparatus in an example of the present invention.

FIG. 8 is a diagram showing a relationship between a denitration rate, a space velocity, and a particle diameter in an example of the present invention.

FIG. 9 is a diagram showing a comparison between the conventional dry desulfurization / denitration apparatus and the dry desulfurization / denitration apparatus of the present invention with respect to the denitration rate for each compartment.

FIG. 10 is a diagram comparing the conventional dry desulfurization / denitration apparatus with the dry desulfurization / denitration apparatus of the present invention with respect to the space velocity of each compartment.

[Explanation of symbols]

 17 Catalyst 36 Upper distribution hopper 37 Catalyst inlet 38 Lower inverted conical section 39 Chute inlet 42, 43 Upper hopper 45 Hopper chamber 47 Chute 55 Moving bed

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B01D 53/34

Claims (3)

(57) [Claims] 1. An upper distribution hopper having (a) a catalyst inlet on an upper wall and a lower inverted conical portion having an inverted conical shape on a lower wall, and (b) formed in a body having a rectangular cross section. On the partition board
Therefore, a pair of moving layers are defined in each of the compartments , move the catalyst downward, and allow the gas to be treated to pass therethrough. (C) disposed at the upper end of each of the moving layers,
An upper hopper having a plurality of hopper chambers formed in response thereto; and (d) connecting the chute inlets formed at a plurality of locations on the same circle in the lower inverted conical portion at a constant pitch with the hopper chambers. (E) the catalyst is dropped from the catalyst inlet to a central portion in the upper distribution hopper, and a column in the upper distribution hopper is formed .
Form a mountain with a predetermined angle of repose in the shape part , and
Ri Atsuma the same particle size distribution in the circumferential direction, part of the cylindrical
From the lower inverted cone below the minute
Re dry desulfurization and denitration apparatus according to claim Rukoto. 2. The dry desulfurization / denitration apparatus according to claim 1, wherein (a) a purge hole is formed at a lowermost portion of the lower inverted conical portion, and (b) a purge pipe is connected to the purge hole. Wherein the gas to be treated supply chamber is arranged to (a) each moving layers, (b) said in claim 1 in which the pair of the treated gas discharge chamber on the outside of the transfer layer is disposed The dry desulfurization / denitration apparatus described in the above.