CN101721901A - Flue gas desulfurization and denitration purifying device in chimney of horizontal flue - Google Patents

Abstract

A horizontal flue-chimney flue gas desulfurization and denitrification purification device, including a horizontal flue internal purification system, a chimney internal purification system, and an absorbent system. The internal purification system of the horizontal flue is a double-layer non-overflow sieve plate structure composed of a sieve plate frame and a sieve plate, and is equipped with a front and a rear baffle, so that the flue gas passes through the lower sieve plate and enters the upper sieve plate, forming a flow from the bottom to the upper sieve plate. The supreme double-layer washing and absorbing process. The purification system in the chimney includes the water baffle frame, the corrugated water baffle and the sump arranged along the slope at the bottom of the chimney. For the double-sided air intake system, the water baffles on both sides just form a V-shaped structure. The absorbent system includes a settling tank, a pulping tank, a circulation pump and pipelines. The invention completes the flue gas purification process of the coal-fired boiler in the horizontal flue and the chimney, simplifies the flue gas purification system of the coal-fired thermal power plant, and installs the desulfurization and denitrification device in the flue and the chimney, reduces the system footprint and improves the purification efficiency , especially suitable for use in the field of flue gas purification of small and medium-sized coal-fired thermal power systems.

Description

Horizontal flue-flue gas desulfurization and denitrification purification device in the chimney

【Technical field】：

The invention belongs to the technical field of environmental protection, in particular to a flue gas desulfurization and denitrification purification device.

【Background technique】:

Most of the flue gas purification of industrial boilers in my country adopts the form of multi-tube dust collector and desulfurization device in series, and large power plants use the form of multi-stage electrostatic precipitator and desulfurization device in series. For industrial boilers, some dust removal and desulfurization equipment have also appeared on the market, but their systems are not perfect and their structures are flawed. In recent years, with the improvement of emission requirements, some manufacturers have added a simple desulfurizer after the multi-tube dust collector. The efficiency of desulfurization and dust removal still cannot meet the current environmental protection emission standards.

In order to meet the requirements of environmental protection projects, for small and medium-sized thermal power plant boilers, domestic desulfurization products generally have the following problems: the equipment system is complicated, and the operating procedures are not suitable for small and medium-sized users; The induced draft fan cannot work normally; fouling and ash blockage occur during the operation of adding alkali; the flue gas resistance is large, the energy consumption is high, and the fan needs to be replaced, and the flue gas purification system cannot operate normally and perform effective flue gas desulfurization, denitrification and dust removal.

The imported flue gas purification system is mainly to meet the needs of flue gas desulfurization of thermal power units with large capacity and high parameters. Its system is complete and reliable in operation. However, there are problems such as high equipment cost, complicated operation and high operation cost when this system is used in the flue gas purification projects of my country's vast industrial boilers and small and medium-sized coal-fired thermal power plants.

On the basis of foreign mature desulfurization process and normal desulfurization, it is necessary to develop a combined purification device with high efficiency, low resistance, dust removal, desulfurization and denitrification, which is suitable for the vast number of industrial boilers and small and medium-sized thermal power plant boilers in my country.

[Content of the invention]: The object of the present invention is to overcome the above-mentioned deficiencies in the prior art, and provide a horizontal flue-flue gas desulfurization and denitrification purification device in the chimney. The device can be applied to the flue gas purification project of small and medium-sized coal-fired thermal power plants. It realizes the installation of desulfurization and denitrification devices in the flue and chimney, which can save installation space and construction funds. It is a scientific flue gas purification method.

The horizontal flue-flue gas desulfurization and denitrification purification device in the chimney provided by the present invention includes a horizontal flue internal purification system arranged in the horizontal flue and a chimney internal purification system arranged at the bottom of the chimney, and the horizontal flue internal purification system is double Layer non-overflow sieve plate structure, consisting of: sieve plate frame, the sieve plate frame is set in the horizontal flue through the bottom support and does not contact the flue wall, the sieve plate frame is equipped with a sieve plate, the front end of the sieve plate frame and the upward There is a front baffle extending to the flue wall, a rear baffle is installed on the rear end of the sieve frame and extending downward to the flue wall, a spraying part is installed above the sieve frame, and a backwash spray is installed below the sieve frame. The front of the sieve plate frame is also equipped with a pre-spraying part; the purification system in the chimney includes: a water baffle frame arranged along an inclined plane at the bottom of the chimney at the interface of the horizontal flue, and a corrugated baffle is arranged in the water baffle frame The water plate, and the water retaining plate frame and the corrugated water retaining plate are inclined towards the air intake direction, and a water collection tank is arranged under the water retaining plate frame. A backwashing spray part is also arranged on the oblique upper side of the corrugated water baffle.

The purification device also includes an absorbent system. The components of the absorbent system are used for the preparation, circulation, sedimentation and treatment of desulfurization and denitrification agents. Pool and absorbent pool, the circulating liquid in the purification system in the horizontal flue and the purification system in the chimney flows into the absorbent pool through the pipeline, and then enters the sedimentation tank together with the lye in the pulping tank, and the regenerated absorbent in the sedimentation tank It is sent back to the purification system by the circulating water pump for recycling.

The absorbent is inhaled by the circulating pump and transported into the flue gas purification system through the pipeline. The absorbent reacts with the harmful gas in the flue gas, and the product enters the sedimentation tank along with the ash liquid, and the sediment and dust are formed after air contact (aeration). Sedimentation in the sedimentation tank. During the flowing process, the circulating liquid is added to the alkali liquor in the pulping tank and the absorbent in the absorbent tank, and the regenerated absorbent is pumped back to the purification system for recycling by the circulating water. In order to ensure a certain purification efficiency during operation, the amount of absorbent added can be changed according to the change of pH value in the return liquid.

Advantage and positive effect of the present invention:

The invention is a flue gas purification product which saves floor space and reduces system investment. The horizontal flue-flue gas desulfurization and denitrification purification device in the chimney utilizes the concrete flue and chimney of the original thermal power plant building, and installs desulfurization and denitrification components inside to make full use of the space between the flue and chimney and reduce the floor space of the desulfurization and denitrification tower , Simplifies the flue gas purification system and reduces environmental protection investment.

The invention simplifies the complex desulfurization system, increases the denitrification function, reduces the desulfurization cost, is easy to operate and reliable in operation, and can be used for flue gas purification of newly-built and under-construction boilers, and can also be used for flue gas purification of existing small and medium-sized thermal power plant boilers Engineered.

[Description of drawings]:

Fig. 1 is a cross-sectional view of the flue gas desulfurization and denitrification purification device in the horizontal flue-chimney;

Fig. 2 is a flow chart of the flue gas desulfurization and denitrification purification device in the horizontal flue-chimney.

In the figure, 1 pre-spraying part, 2 front baffle, 3 backwash spraying part, 4 sieve plate frame, 5 rear baffle, 6 sieve plate, 7 spraying part, 8 anti-corrosion layer, 9 water retaining plate frame, 10 corrugated water baffle, 11 backwashing spray parts, 12 sump, 13 settling tank, 14 pulping tank, 15 circulation pump, 16 pipeline, 17 absorbent tank.

【Detailed ways】:

Example 1:

The invention provides a horizontal flue-chimney flue gas desulfurization and denitrification purification device, including a horizontal flue internal purification system, a chimney internal purification system, and an absorbent system.

The purification system in the horizontal flue described therein is a double-layer non-overflow sieve plate structure, which is used to purify the flue gas. Its composition is shown in Figure 1, including: 1 pre-spray components, 2 front baffles, 3 backwash spray Components, 4 sieve plate frame, 5 rear baffle, 6 sieve plate, 7 spray parts, 8 anti-corrosion layer.

The sieve plate frame 4, the sieve plate frame is set in the horizontal flue through the bottom support and does not contact with the flue wall, the sieve plate 6 is arranged in the sieve plate frame, the front end surface of the front end of the sieve plate frame and extending upward to the flue wall are provided with front baffles Plate 2, the rear end face of the sieve plate frame and extending downward to the flue wall are provided with a back baffle 5, the spray part 7 is provided above the sieve plate frame, the backwash spray part 3 is provided below the sieve plate frame, and the sieve plate The front of the frame is also provided with a pre-spray component 1 .

Among them: the pre-spray part 1 is the first-stage flue gas washing process, the front baffle 2 and the rear baffle 5 block the flue gas in the horizontal flue, and guide the flue gas into the washing bed. The sieve frame 4 and the sieve 6 form a washing bed. The anticorrosion layer 8 on the inner wall of the flue is to protect the corrosion of the horizontal concrete flue.

The purification system in the chimney is shown in Figure 2, comprising: a water retaining plate frame 9 arranged along an inclined plane at the bottom of the chimney at the interface of the horizontal flue, a corrugated water retaining plate 10 is arranged in the water retaining plate frame, and the retaining plate The water plate frame and the corrugated water retaining plate are tilted toward the air intake direction, and a water collecting tank 12 is arranged under the water retaining plate frame. Also be provided with the backwash spray part on the oblique top of the corrugated water baffle? 11. For the purification system in the chimney with double-sided air intake, the water retaining frame on both sides and the corrugated water retaining plate are combined to form a V-shaped structure (see Figure 2).

The absorbent system is shown in Figure 2, including: 13 settling tanks, 14 pulping tanks, 15 circulation pumps, 16 pipelines, 17 absorbent tanks, forming a water retaining and demisting section after flue gas purification. The components contained in the absorbent system are used for the preparation of desulfurization and denitrification agent, the circulation of desulfurization and denitrification agent, the settlement of washing liquid after reaction and the treatment function. The lye enters the settling tank together, and the regenerated absorbent in the settling tank is sent back to the purification system by the circulating water pump for recycling. (see the content of the invention for the working process)

working principle

After the high-temperature flue gas enters the horizontal flue, it is first pre-sprayed, humidified and atomized by part 1, the flue gas is humidified and cooled, the flue dust collides with the water mist, condenses, granulates, and the sulfur dioxide and nitrogen oxides in the flue gas are absorbed by the lye , forming the first stage of purification.

The purification system in the horizontal flue adopts a two-stage non-overflow grouped sieve plate structure to form an effective fluidized bed flow form, increase the reaction time between the flue gas and the absorbent, and fully mix and contact the flue gas and the absorption liquid. The flow section of the flow structure has been used in many projects, and the desulfurization effect meets the emission standards.

After the flue gas carrying smoke dust and water mist passes through the backwash spray of part 3 and the sieve plate of part 6, the flue gas collides with the lye at high speed, and the airflow will pass through the boiling liquid surface in a bead shape, and the effective contact area between the flue gas and the absorption liquid increases , a more effective absorption process is formed during the contact of flue gas with lye. After the flue gas is absorbed, it flows upwards and collides with the absorbent dripped from the upper sieve plate, thereby strengthening the mixing and forming a reaction process during this flow process. When the flue gas enters the secondary sieve plate, a reaction process similar to that of the previous stage is formed.

Component 7 spray equipment is installed on the upper part of the device, and the flue gas is further contacted and reacted with the falling absorbent while being purified, so as to improve the reliability of the device operation.

The purified flue gas enters the purification system in the chimney, which demistes the purified flue gas, removes liquid droplets in the flue gas, and ensures that the exhaust gas does not contain liquid moisture. The demister is made of high-grade engineering plastics, and a flushing device is installed to ensure that the demister is not blocked or scaled.

The solidified matter settles in the settling tank, and the clarified liquid is sent back to use by the circulating water pump after being treated. In order to ensure reliable purification efficiency during operation, the amount of alkali added can be changed according to the change of the pH value in the return liquid (to ensure that the pH value of the return liquid is constant). After adjusting the pH value, the lye is sent back to the equipment, and the desulfurizer and circulating water are recycled.

Claims (3)

1. A horizontal flue-flue gas desulfurization and denitrification purification device in the chimney, characterized in that the purification device includes a purification system in the horizontal flue arranged in the horizontal flue and a purification system in the chimney arranged at the bottom of the chimney, and the horizontal flue The composition of the purification system includes: a sieve plate frame, the sieve plate frame is set in the horizontal flue through the bottom support and does not contact the flue wall, a sieve plate is arranged in the sieve plate frame, the front end surface of the sieve plate frame extends upward to the flue wall A front baffle is provided, a rear baffle is provided on the rear end of the sieve frame and extends downwards to the flue wall, a spraying part is arranged above the sieve frame, a backwashing spray part is arranged under the sieve frame, and the sieve The front of the frame is also equipped with pre-spraying parts; the purification system in the chimney includes: a water baffle frame arranged along an inclined plane at the bottom of the chimney at the interface of the horizontal flue, and a corrugated water baffle is arranged in the water baffle frame, and the water baffle The water plate frame and the corrugated water retaining plate are inclined towards the air intake direction, and a water collecting tank is arranged under the water retaining plate frame. 2. The purification device according to claim 1, characterized in that a backwashing spray part is arranged obliquely above the corrugated water baffle in the purification system in the chimney. 3. The purification device according to claim 1, characterized in that the purification device also includes an absorbent system, and the components contained in the absorbent system are used to form desulfurization and denitrification agent preparation, circulation, sedimentation and treatment functions, and its composition Including: the settling tank, the pulping tank and the absorbent tank connected together by pipelines, the circulating liquid in the purification system in the horizontal flue and the purification system in the chimney flows into the absorbent tank through the pipeline, and then mixes with the alkali in the pulping tank The liquid enters the settling tank together, and the regenerated absorbent in the settling tank is sent back to the purification system by the circulating water pump for recycling.

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