CN216367388U - Semidry flue gas desulfurization device - Google Patents

Abstract

The utility model discloses a semidry flue gas desulfurization device which comprises a desulfurization tower, a flue and a Venturi tube bundle used for communicating the desulfurization tower and the flue, wherein the inlet and the outlet of the Venturi tube bundle are respectively connected with the outlet of the flue and the inlet of the desulfurization tower. On one hand, by arranging the multi-tube-bundle venturi tube, the uniformity of a flow field in the desulfurizing tower is effectively improved, the mixing uniformity of the flue gas and the desulfurizing agent is promoted, and the desulfurizing efficiency is improved; on the other hand, the throat pipe of the Venturi tube is connected with the desulfurizing tower through the flue gas circulating pipe, negative pressure generated at the throat pipe of the edge Venturi tube is fully utilized, self-circulation of flue gas in the tower is realized, energy consumption of a draught fan is reduced, the residence time of the flue gas in the desulfurizing tower is increased, the circulation multiplying power of the flue gas is improved, the utilization rate of slaked lime is improved, and the stability of the flue gas amount of the desulfurizing tower under the low-load working condition is ensured.

Description

Semidry flue gas desulfurization device

Technical Field

The utility model belongs to the technical field of environmental protection engineering, and particularly relates to a semidry flue gas desulfurization device.

Background

Sulfur dioxide pollution is a main factor for forming acid rain, can seriously pollute the ecological environment and endanger the health of animals and plants. With the increasing environmental protection situation, people pay more attention to environmental protection, strengthening flue gas treatment and reducing sulfur dioxide emission, and become the key points of social attention gradually.

Currently mainstream flue gas desulfurization processes include: ammonia desulfurization, wet desulfurization typified by limestone-gypsum desulfurization, active coke-dry desulfurization, and CFB semi-dry desulfurization. The ammonia desulphurization process takes liquid ammonia or ammonia water as a desulfurizer, the byproduct is ammonium sulfate, the desulphurization efficiency is high, but the use of the process is gradually limited along with the problem of secondary pollution of ammonia gas; the wet desulphurization process represented by a limestone-gypsum method has high desulphurization efficiency, but has poor smoke discharging effect, can generate 'plume', has high requirement on corrosion resistance of equipment, and has more auxiliary equipment for matched operation; the active coke process has large occupied area and high investment cost.

The CFB semi-dry desulfurization process has simple equipment, no moving parts in the whole desulfurization tower, high desulfurization efficiency and secondary utilization of desulfurization byproducts, thereby being widely used. The core of the CFB semi-dry desulfurization process lies in maintaining the uniformity of the flue gas distribution at the inlet of the desulfurization tower and the stability of the flue gas quantity, and preventing the desulfurization tower from collapsing under the condition of low load. At present, the main stream adopts a mode of circularly returning clean flue gas after the induced draft fan to the inlet of the desulfurizing tower to ensure that the flue gas volume at the desulfurizing inlet is stable, and the power consumption of the induced draft fan is higher.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the problem of high power consumption of a draught fan in a CFB semi-dry desulfurization process by providing a semi-dry flue gas desulfurization device, and further improve the uniformity and stability of the flue gas amount in a desulfurization tower.

The utility model is realized by the following steps:

a semidry flue gas desulfurization device is characterized in that: the device comprises a desulfurizing tower, a flue gas circulating pipe and a Venturi tube bundle for communicating the desulfurizing tower and the flue, wherein the inlet and the outlet of the Venturi tube bundle are respectively connected with the outlet of the flue and the inlet of the desulfurizing tower;

the venturi tube bundle comprises a central venturi tube and a plurality of edge venturi tubes uniformly distributed around the central venturi tube;

one end of the flue gas circulating pipe is connected with the desulfurizing tower, and the other end of the flue gas circulating pipe is connected with a throat pipe of the edge Venturi tube of the Venturi tube bundle.

Preferably, the range of the gradually-reducing angle of the central Venturi tube is 30-60 degrees, and the gradually-widening angle is 10-30 degrees; the range of the edge Venturi tube taper angle is 20-60 degrees, and the taper angle is 8-30 degrees.

Preferably, the throat diameter of the edge venturi is 0.8 to 1.2 times the throat diameter of the central venturi.

Preferably, all still be equipped with the baffle that is used for preventing to leak the cigarette between venturi restraints and flue and the desulfurizing tower, open on the baffle with venturi restraints the position and the corresponding through-hole of size all, venturi restraints with the welding of through-hole one-to-one is in on the baffle.

Preferably, the flue gas circulating pipe is obliquely connected to the side surface of the throat pipe of the edge Venturi tube, and an included angle between the flue gas circulating pipe and the throat pipe of the edge Venturi tube is 20-40 degrees.

Preferably, the pipe diameter of the flue gas circulating pipe is 0.5-0.8 times of that of the edge Venturi throat pipe.

Preferably, the flue gas circulating pipe is provided with a horizontal section with the lowest point, the horizontal section is provided with a purging pipe for preventing desulfurization ash from being accumulated in a transition mode, and the other end of the purging pipe is connected with an air pump or a compressed air cylinder.

Preferably, venturi center venturi and marginal venturi inner wall are equipped with the wearing layer that adopts wear-resisting material to make.

The utility model has the beneficial effects that:

the utility model provides a semidry flue gas desulfurization device, which effectively improves the uniformity of a flow field in a desulfurization tower, promotes the mixing uniformity of flue gas and a desulfurizing agent and improves the desulfurization efficiency by arranging a multi-tube-bundle venturi tube; on the other hand, the throat pipe of the Venturi tube is connected with the desulfurizing tower through the flue gas circulating pipe, negative pressure generated at the throat pipe of the edge Venturi tube is fully utilized, self-circulation of flue gas in the tower is realized, energy consumption of a draught fan is reduced, the residence time of the flue gas in the desulfurizing tower is increased, the circulation multiplying power of the flue gas is improved, the utilization rate of slaked lime is improved, and the stability of the flue gas amount of the desulfurizing tower under the low-load working condition is ensured.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a semidry flue gas desulfurization apparatus according to an embodiment of the present invention;

fig. 2 is a cross-sectional view of a venturi tube bundle in a semidry flue gas desulfurization device according to an embodiment of the present invention.

In the figure: 1-central Venturi tube, 2-edge Venturi tube, 3-baffle, 4-gradually-widening section, 5-throat tube, 6-gradually-shrinking section, 7-flue gas circulating tube, 8-flue, 9-desulfurizing tower, 10-purging tube, 11-compressed air bottle and 12-valve.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1 and 2, the embodiment of the utility model provides a semidry flue gas desulfurization device, which comprises a desulfurization tower 9, a flue 8 and a venturi tube bundle consisting of a plurality of venturi tubes, wherein the desulfurization tower 9 is communicated with the flue 8 through the venturi tube bundle. Specifically, the method comprises the following steps:

the Venturi tube bundle comprises a central Venturi tube 1 arranged in the middle of the bottom of the desulfurizing tower 9 and six edge Venturi tubes 2 uniformly distributed around the circumference of the central Venturi tube 1; venturi center venturi 1 and 2 inner walls of marginal venturi are equipped with the wearing layer that adopts wear-resisting material to make, venturi restraints the entry (gradually reducing section 6 promptly) and exports (gradually widening section 4 promptly) and links to each other with 8 exports of flue and the entry of desulfurizing tower 9 respectively, through venturi restraints and enables the flue gas and get into in the desulfurizing tower 9 with higher speed to integrate the fluidization with irregular flue gas stream, fall into the stranded air current and get into, guarantee the homogeneity in the 9 interior flow fields of desulfurizing tower, flue gas and absorbent and circulation desulfurization ash can intensive mixing and suspend and form the fluidized bed under the impact of air current, thereby carry out abundant vulcanization.

Because the divergent angle and the convergent angle of the Venturi tube can also cause certain influence on the flow field in the absorption tower: too little divergent angle can make venturi outlet air current unable effective diffusion, leads to the air current rigidity too big, and upper portion flue gas velocity of flow is too high, and too big divergent angle can lead to the too early inflation of air current, forms the backward flow at diffuser segment limit wall, can't carry out effective fluidization to the upper portion bed body, and the convergent angle then admits air to the lower part and plays the water conservancy diversion effect, and the size of convergent angle has directly decided the speed and the flow size that get into venturi air current. Therefore, in the present embodiment, the gradually widening angle and the gradually narrowing angle of the central venturi tube 1 and the peripheral venturi tube 2 of the venturi tube bundle are different, specifically, the gradually narrowing angle of the central venturi tube 1 ranges from 30 ° to 60 °, and the gradually widening angle ranges from 10 ° to 30 °; the range of the taper angle of the edge Venturi tube 2 is 20-60 degrees, the taper angle is 8-30 degrees, the diameter of the taper section 6 of the Venturi tube and the diameter change of the throat tube 5 of the edge Venturi tube are matched with the taper angle, wherein the diameter of the throat tube 5 of the edge Venturi tube 2 is 0.8-1.2 times of the diameter of the throat tube 5 of the central Venturi tube 1, so that the phenomena of bias flow and backflow in a flow field of a desulfurizing tower 9 are effectively reduced, the uniformity of a flue gas flow field at the inlet of the desulfurizing tower 9 is improved, and the stable operation of the desulfurizing tower 9 is ensured.

The export of flue 8 with between the convergent section 6 of venturi restrainted, and the entry of desulfurizing tower 9 with all still be equipped with baffle 3 between the gradually-widening section 4 of venturi restrainted, it is corresponding, baffle 3 also open have with the gradually-widening section 4 of venturi restrainted or the gradually-widening section 6 the same, the corresponding through-hole in position of quantity, the aperture of through-hole equals with the diameter of gradually-widening section 4 or convergent section 6 respectively, central venturi 1 with marginal venturi 2 with the welding of through-hole one-to-one is in on the baffle 3.

In order to realize the self-circulation of the flue gas in the desulfurizing tower 9 and reduce the energy consumption, the desulfurizing tower also comprises a plurality of flue gas circulating pipes 7, one end of each flue gas circulating pipe 7 is arranged on the side wall of the desulfurizing tower 9, and the other end of each flue gas circulating pipe 7 is communicated with the throat pipe 5 of the edge Venturi tube 2; through the low-pressure entrainment effect of the throat 5 department of make full use of marginal venturi 2, make the flue gas in the desulfurizing tower 9 follow again during flue gas circulating pipe 7 flows back marginal venturi 2, realize the self-loopa of flue gas, the circulation multiplying power of flue gas has been improved, the stability of desulfurizing tower 9 entry flue gas volume under the low-load operating mode has been guaranteed, and can also reduce the flue gas volume of 8 extrinsic cycles of circulation flue to a certain extent through flue gas self-loopa in the desulfurizing tower 9, be favorable to reducing the energy consumption of draught fan, further reduce the running cost of desulfurization system, the mass transfer condition of flue gas and lime hydrate has been improved, the utilization ratio and the desulfurization efficiency of lime hydrate have been improved.

Furthermore, the pipe diameter of the flue gas circulating pipe 7 is 0.5-0.8 times of the pipe diameter of the throat pipe 5 of the edge Venturi tube 2, the flue gas circulating pipe 7 is connected to the side wall of the throat pipe 5 of the edge Venturi tube 2 in an upward and oblique mode, and an included angle between the flue gas circulating pipe 7 and the throat pipe 5 of the edge Venturi tube 2 is 20-40 degrees, so that the flowing direction of the returned flue gas can be kept consistent with the flowing direction of the flue gas in the Venturi tube as much as possible, and impact and friction of the flue gas on the inner wall of the throat pipe 5 are reduced.

In a preferred embodiment, the flue gas circulation pipe 7 has a horizontal section with the lowest point, the horizontal section of the flue gas circulation pipe 7 is provided with a purging pipe 10, the other end of the purging pipe 10 is connected with an air pump or a compressed air bottle 11, and a valve 12 is arranged, when needed, high-speed air flow can be sprayed into the flue gas circulation pipe 7 by opening the valve 12, so that large-particle desulfurized ash deposited at the bottom of the flue gas circulation pipe 7 can be blown loose and can flow back to the desulfurizing tower 9 for reaction again, and the desulfurized ash is prevented from being excessively deposited in the pipe to block the flue gas circulation pipe 7.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the utility model, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (9)

1. A semidry flue gas desulfurization device is characterized in that: the device comprises a desulfurizing tower, a flue gas circulating pipe and a Venturi tube bundle for communicating the desulfurizing tower and the flue, wherein the inlet and the outlet of the Venturi tube bundle are respectively connected with the outlet of the flue and the inlet of the desulfurizing tower;

the venturi tube bundle comprises a central venturi tube and a plurality of edge venturi tubes uniformly distributed around the central venturi tube;

one end of the flue gas circulating pipe is connected with the desulfurizing tower, and the other end of the flue gas circulating pipe is connected with a throat pipe of the edge Venturi tube.

2. The semidry flue gas desulfurization apparatus according to claim 1, wherein: the range of the gradually-reducing angle of the central Venturi tube is 30-60 degrees, and the gradually-widening angle is 10-30 degrees; the range of the edge Venturi tube taper angle is 20-60 degrees, and the taper angle is 8-30 degrees.

3. The semidry flue gas desulfurization apparatus according to claim 2, wherein: the diameter of the throat pipe of the edge Venturi pipe is 0.8-1.2 times of that of the throat pipe of the central Venturi pipe.

4. The semidry flue gas desulfurization apparatus according to claim 1, wherein: all still be equipped with the baffle that is used for preventing to leak the cigarette between venturi restraints and flue and the desulfurizing tower, open on the baffle with venturi restraints the position and the all corresponding through-hole of size, venturi restraints the access & exit with the welding of through-hole one-to-one on the baffle.

5. The semidry flue gas desulfurization apparatus according to claim 1, wherein: the flue gas circulating pipe is obliquely connected to the side surface of the throat pipe of the edge Venturi tube.

6. The semi-dry flue gas desulfurization apparatus according to claim 5, wherein: the included angle between the flue gas circulating pipe and the throat pipe of the edge Venturi tube is 20-40 degrees.

7. The semi-dry flue gas desulfurization apparatus according to claim 5, wherein: the pipe diameter of the flue gas circulating pipe is 0.5-0.8 times of that of a throat pipe of the edge Venturi tube.

8. The semi-dry flue gas desulfurization apparatus according to claim 5, wherein: the flue gas circulating pipe is provided with a horizontal section with the lowest point, and the horizontal section is provided with a purging pipe for preventing transitional accumulation of desulfurized fly ash.

9. The semidry flue gas desulfurization apparatus according to any one of claims 1 to 8, wherein: the inner walls of the central Venturi tube and the edge Venturi tube are provided with wear-resistant layers made of wear-resistant materials.

Images