CN210009826U

CN210009826U - Limestone gypsum wet desulphurization device

Info

Publication number: CN210009826U
Application number: CN201920436611.9U
Authority: CN
Inventors: 韩小卫; 钱义龙
Original assignee: Jiangsu Xinhuanneng Environment Protection Engineering Co Ltd
Current assignee: Jiangsu Xinhuanneng Environment Protection Engineering Co Ltd
Priority date: 2019-04-02
Filing date: 2019-04-02
Publication date: 2020-02-04
Anticipated expiration: 2029-04-02

Abstract

The utility model discloses a limestone gypsum wet flue gas desulfurization device, including absorption tower, thick liquid pond, gypsum swirler, hydroextractor and oxidation fan, the thick liquid pond set up in the absorption tower, the thick liquid pond is equipped with lime thick liquid entry, overflow backward flow mouth and oxygen entry, the overflow of gypsum swirler is followed overflow backward flow mouth flows in the thick liquid pond, a serial communication port, the setting height that sets up of lime thick liquid entry is higher than overflow backward flow mouth and oxygen entry, overflow backward flow mouth and oxygen entry set up the difference in height and be not more than 0.5m, the lime thick liquid entry with overflow backward flow mouth set up the difference in height and be greater than 1 m. The utility model discloses the activity of lime thick liquid can be guaranteed to the device, ensures sulfur dioxide's absorption rate and easy to carry out.

Description

Limestone gypsum wet desulphurization device

Technical Field

The utility model relates to a desulphurization unit especially relates to a lime stone gypsum wet flue gas desulfurization device.

Background

The main principle of limestone-gypsum wet desulfurization is to use limestone or lime as desulfurizing absorbent, the limestone is crushed and ground into powder, and the powder is mixed with water and stirred into absorption slurry, when lime is used as absorbent, the lime powder is digested and then added with water to prepare the absorbent slurry. In the absorption tower, the absorption slurry is contacted and mixed with the flue gas, the sulfur dioxide in the flue gas is chemically reacted with the calcium carbonate in the slurry and the blown oxidizing air so as to be removed, and the final reaction product is gypsum.

The existing limestone-gypsum wet desulphurization device comprises an absorption tower, a slurry pool, a demister, a gypsum cyclone and a dehydrator, wherein the absorption tower is of a countercurrent spray empty tower structure, the absorption and oxidation functions are integrated, the upper part is an absorption area, the lower part is a slurry pool, and flue gas subjected to dust removal is in reverse contact with circulating slurry in the absorption tower. The upper part of the absorption zone is provided with a demister, and the free moisture in the flue gas at the outlet of the demister is not more than 75mg/Nm 3. Absorption of SO₂And the slurry enters a slurry pool for cyclic oxidation, and the calcium sulfite is oxidized into gypsum crystals by blown air in the slurry pool. And discharging the slurry of the reaction product in the slurry tank to a gypsum cyclone when the slurry reaches a certain density, discharging the slurry from the gypsum cyclone to a dehydrator for dehydration, and refluxing the overflow of the gypsum cyclone to the slurry tank.

In the prior art, an overflow process pipeline of a gypsum cyclone and a make-up liquid inlet pipeline of a slurry pool are arranged on the same layer, the overflow of the gypsum cyclone can participate in the reaction process of new liquid, but the backflow liquid mainly comprises unreacted and sufficient heavy metals such as sulfite and dust, and thus, the dust can destroy the reaction. In addition, at this time, the slurry mostly uses calcium sulfite hemihydrate, so that calcium sulfate in the slurry is difficult to grow and dehydrate, a large amount of slurry is supplied for ensuring that outlet sulfur dioxide reaches the standard, and the large amount of calcium sulfate hemihydrate and calcium sulfate which cannot be dehydrated in the slurry prevent the decomposition of calcium carbonate and the absorption of sulfur dioxide, so that the activity of the slurry is greatly reduced, which is the most complicated and difficult to treat.

SUMMERY OF THE UTILITY MODEL

To the defect of above-mentioned prior art, the utility model provides a limestone gypsum wet flue gas desulfurization device solves the thick liquid pond thick liquid reactivity low, to the problem that sulfur dioxide's absorption rate descends.

The utility model discloses technical scheme as follows: the utility model provides a limestone gypsum wet flue gas desulfurization device, includes absorption tower, thick liquid pond, gypsum swirler, hydroextractor and oxidation fan, the thick liquid pond set up in the absorption tower, the thick liquid pond is equipped with lime thick liquid entry, overflow backward flow mouth and oxygen entry, the overflow of gypsum swirler is followed overflow backward flow mouth flows in the thick liquid pond, the setting height of lime thick liquid entry is higher than overflow backward flow mouth and oxygen entry, overflow backward flow mouth and oxygen entry set up the difference in height and be not more than 0.5m, lime thick liquid entry with overflow backward flow mouth set up the difference in height and be greater than 1 m.

Further, the height of the overflow return port is not less than 2.5m from the bottom of the slurry pool.

Preferably, the height of the overflow return opening is 2.8-3.1 m away from the bottom of the slurry pool.

Preferably, the lateral wall of thick liquid pond is equipped with the side agitator, the side agitator pivot is the horizontal direction, the difference in height that sets up of side agitator and oxygen entry is not more than 0.5m, the difference in height that sets up of side agitator and overflow backward flow mouth is not more than 0.5 m.

Compared with the prior art, the utility model, technical scheme can realize following beneficial effect:

the gypsum cyclone containing sulfite and dust overflows and flows back to the slurry tank and then can fully react with oxygen to generate calcium sulfate in a contact way, so that the calcium sulfate can be prevented from directly contacting with lime slurry stock solution of the slurry tank, the system balance of lime and sulfur dioxide is destroyed, the activity of lime slurry is ensured, and the absorption rate of the sulfur dioxide is ensured to meet the desulfurization requirement. The device is easy to implement based on the existing limestone-gypsum wet desulphurization device, and has the advantages of less modification equipment, low cost and contribution to popularization and implementation.

Drawings

Fig. 1 is a schematic structural view of a limestone-gypsum wet desulfurization apparatus.

Detailed Description

The present invention is further described in connection with the following examples, which are intended to illustrate the invention and not to limit the scope of the invention, which, after reading the present invention, are intended to cover modifications of the invention in its various equivalent forms by those skilled in the art, which fall within the scope of the appended claims.

Referring to fig. 1, the limestone-gypsum wet desulfurization apparatus according to the present embodiment includes an absorption tower 1, a slurry tank 2, a gypsum cyclone 3, a vacuum dewatering belt conveyor 4, and an oxidation fan 5, wherein a demister 6, a spray layer 7, and the slurry tank 2 are sequentially disposed in the absorption tower 1 from top to bottom. The bottom of the slurry pool 2 is connected with a gypsum pump 8 through a pipeline 9. The reacted calcium sulfate slurry and the small amount of unreacted calcium sulfite slurry and other impurities in the absorption tower 1 are pumped into the gypsum cyclone 3 through a gypsum pump 8 through a pipeline 9. The gypsum cyclone 3 concentrates and classifies the slurry pumped by the gypsum pump 8, the dilute overflow returns to the absorption tower 1 through an overflow pipeline 10 and enters the slurry tank 2 from an overflow return port 2a, and the concentrated underflow is sent to the vacuum dehydration belt conveyor 4 for gypsum dehydration. Lime slurry is supplemented in the slurry pool 2 through a lime slurry inlet 2b, and an oxidation fan 5 is connected to an oxygen inlet 2c of the slurry pool 2 through an air pipeline to supplement oxygen for the slurry in the slurry pool 2. On slurry pond 2, lime thick liquid entry 2b set up highly be higher than overflow return port 2a and oxygen entry 2c, and overflow return port 2a and oxygen entry 2c set up the difference in height and be not more than 0.5m, and lime thick liquid entry 2b and overflow return port 2a set up the difference in height and be greater than 1m, and overflow return port 2a sets up the bottom of high distance slurry pond 2 and is 2.8 ~ 3.1m, and the selection of this embodiment is about 3 m. In addition, a side stirrer 11 is arranged on the side wall of the slurry pool 2, the rotating shaft of the side stirrer 11 is in the horizontal direction, the height difference between the side stirrer 11 and the oxygen inlet 2c is not more than 0.5m, and the height difference between the side stirrer 11 and the overflow return port 2a is not more than 0.5 m. The above arrangement is such that the side stirrer 11, the oxygen inlet 2c and the overflow return 2a are located substantially at the same reaction layer level of the slurry in the slurry tank 2, below the layer of fresh lime slurry. The solid content of the overflow of the gypsum cyclone 3 is about 1-3% (mass content), the solid phase particles are fine, and the solid phase particles are mainly an absorbent which is not completely reacted, small gypsum crystals and the like. The incompletely reacted absorbent continues to participate in the desulfurization reaction, and the small gypsum crystals are used as crystal nuclei for crystal growth in the slurry tank, so that the formation of large gypsum crystals at the next stage is influenced. Therefore, the waste water flows back to the middle part of the slurry pool 2 to be in contact reaction with supplemented oxygen under the action of the side stirrer 11, and is oxidized into sulfate radicals until qualified calcium sulfate is produced, and gypsum dehydration is carried out again. The solid content of the underflow of the gypsum cyclone 3 is about 45-50% (mass content), the solid phase is mainly coarse gypsum crystals, and the purpose of the vacuum dewatering belt conveyor 4 is to remove free water among the large crystal particles.

Claims

1. The utility model provides a limestone gypsum wet flue gas desulfurization device, includes absorption tower, thick liquid pond, gypsum swirler, hydroextractor and oxidation fan, the thick liquid pond set up in the absorption tower, the thick liquid pond is equipped with lime thick liquid entry, overflow backward flow mouth and oxygen entry, the overflow of gypsum swirler is followed overflow backward flow mouth flows in the thick liquid pond, its characterized in that, the setting height of lime thick liquid entry is higher than overflow backward flow mouth and oxygen entry, overflow backward flow mouth and oxygen entry set up the difference in height and be not more than 0.5m, lime thick liquid entry with overflow backward flow mouth set up the difference in height and be greater than 1 m.

2. The limestone-gypsum wet desulphurization device according to claim 1, wherein the height of the overflow return port is not less than 2.5m from the bottom of the slurry tank.

3. The limestone-gypsum wet desulphurization device according to claim 1, wherein the height of the overflow return port is 2.8-3.1 m from the bottom of the slurry tank.

4. The limestone-gypsum wet desulphurization device according to claim 1, wherein the side wall of the slurry tank is provided with a side stirrer, the rotation shaft of the side stirrer is in horizontal direction, the height difference between the side stirrer and the oxygen inlet is not more than 0.5m, and the height difference between the side stirrer and the overflow return opening is not more than 0.5 m.