CN105688527A

CN105688527A - A device for removing sulfur dioxide and dioxin from sintering flue gas and a method therefor

Info

Publication number: CN105688527A
Application number: CN201410707381.7A
Authority: CN
Inventors: 徐仁觉; 申忠华; 徐伟; 邱俊兰
Original assignee: JIANGSU KANGJIE ENVIRONMENTAL ENGINEERING Co Ltd
Current assignee: JIANGSU KANGJIE ENVIRONMENTAL ENGINEERING Co Ltd
Priority date: 2014-11-27
Filing date: 2014-11-27
Publication date: 2016-06-22
Anticipated expiration: 2034-11-27
Also published as: CN105688527B

Abstract

The invention relates to a device for removing sulfur dioxide and dioxin from sintering flue gas and a method therefor. The device comprises a quench column, a bag type dust collector, an active-coke-filled absorption column and a bag type dust collector which are connected in order. An active coke purification and filtration plate separates the active-coke-filled absorption column into an upper part and a lower part from the middle. A desulfurizer storer and a water spraying nozzle are disposed in the lower part. A dismountable active-coke purification and filtration layer is adhered to the inner wall of the upper part. The method includes feeding high-temperature sintering flue gas into the quench column, dedusting, chemically reacting, decomposing, reducing, dedusting again, and other steps. Compared with the prior art, the device and the method are reasonable in process can effectively remove the sulfur dioxide, the dioxin and other harmful components from the sintering flue gas. The device is further optimized in structure, can meet process requirements, and is good in purification performance, high in efficiency and low in using cost.

Description

Device and method for removing sulphur dioxide and dioxin from sintering flue gas

Technical field

The present invention relates to fume treatment field, particularly a kind of device and method for removing sulphur dioxide and dioxin from sintering flue gas。

Background technology

Steel and iron industry is the pillar industry of Chinese national economy, and propelling and development for industrialization and urbanization are made that significant contribution。But China's steel and iron industry Environmental Protection Level is low simultaneously, pollutant discharge amount remains high, and seriously restricts the raising of steel industry whole competitiveness。In iron and steel enterprise's discharge waste gas, typical pollutant mainly includes dust, SO2, dioxin pollution thing etc., and in these pollutant, wherein more than 70% SO2, the air dioxin pollution thing of 90% discharges from steel sintering machine。Therefore it is one of the center of gravity of iron and steel pollution treatment to sintering device flue gas pollution control。

Flue gas desulfurization has dry method, semidry method, wet method three kinds。Dry desulfurization is inefficient, although wet desulphurization desulfuration efficiency is higher, but it is big to there is equipment investment, and floor space is big, and water resource waste, the shortcomings such as secondary pollution is serious, therefore the application of wet desulphurization is subject to certain restriction。The present flue gas of sintering machine overwhelming majority adopts semi-dry desulphurization。Semi-dry desulphurization has many kinds, including rotary spraying and drying sulfur removal technology, Circulating Fluidized Bed Process, dense-phase tower method desulfurization skill, ENS semi-dry desulphurization, VAI MEROS sulfur removal technology, LEC semidry methods etc. are multiple, whether adopt and in absorption reaction tower, be injected directly into quick lime serosity and flue gas react, or adopt calcium lime powder and atomized water to react with flue gas at Ta Nei, after end reaction, drop is dried rapidly by sintering flue gas heat, form dry state powder-material, then continued trapping by sack cleaner to purify, therefore semi-dry desulphurization does not produce waste water。

Summary of the invention

The invention provides a kind of device and method for removing sulphur dioxide and dioxin from sintering flue gas, activated coke defecator is set in existing semi-dry desulphurization absorption tower, it is possible to realize sintering flue gas is carried out the purpose of high-efficiency desulfurization, de-dioxin and heavy metal。

It is an object of the invention to by realizing by the following technical solutions:

For sintering the device of flue gas scrubbing CO_2 and dioxin, described device include being sequentially connected connect chilling tower, sack cleaner, activated coke packed absorber, sack cleaner, the cleaned filter plate of activated coke that described activated coke packed absorber is set is divided into upper and lower two parts from middle part, bottom is provided with desulfurizing agent memorizer and water spout, and upper inside wall is fitted with dismountable has the cleaned filtering layer of activated coke。

As the preferred technical solution of the present invention, described sack cleaner is low-pressure jet pulse bag type dust catcher。

As the preferred technical solution of the present invention, described activated coke packed absorber bottom adopts Venturi tube, and described Venturi tube is followed successively by circular cone contraction section, cylindrical section and conical expander section from the bottom up；Described desulfurizing agent memorizer is arranged at circular cone contraction section；Described water spout is arranged at conical expander section, and described circular cone contraction section is arranged below electric cleaner。

As the preferred technical solution of the present invention, the cleaned filtering layer of described activated coke is semi-spherical shape, and protruding sphere is towards entering flue gas direction。

For the method sintering flue gas scrubbing CO_2 and dioxin, comprise the following steps:

Step one: high temperature sintering flue gas sends into chilling tower, flue gas makes temperature be rapidly decreased to 110 DEG C～150 DEG C by humidification after entering chilling tower；

Step 2: the sintering flue gas through rapid cooling is sent into sack cleaner, filters most dust and heavy metal in flue gas, is filtered the dust produced and lead dust is stored in the ash bucket of cleaner unit, by humidifier, dust and lead dust are humidified at regular time and quantity；

Step 3: sintering flue gas removing dust enters activated coke packed absorber, desulfurizer powder Ca (OH) in the desulfurizing agent memorizer of Venturi tube bottom after processing₂Enter bottom activated coke packed absorber, desulfurizing agent mixes with flue gas in absorption tower, in absorption tower, the atomized water of water spout sprays to whole flow of flue gas cross section, and mixed being incorporated in absorption tower of flue gas, desulfurizing agent, water moves upward, sulfur dioxide and desulfurizing agent Ca (OH) simultaneously₂Chemical reaction occurs, and the sulfur dioxide in flue gas is removed；

Step 4: when sintering flue gas filtering layer cleaned by the activated coke in activated coke packed absorber, first the dust in flue gas is filtered by activity focus layer and intercepts；Then the material such as dioxin, sulfur dioxide and heavy metal is by activated coke micro-porous adsorption；Urged by activity coking oxidation or reduce with moisture, oxygen under ADSORPTION STATE at the sulfur dioxide of activated coke micropore surface simultaneously, form dilute sulfuric acid and the water of ADSORPTION STATE；

Step 5: sinter flue gas after filtration and send into sack cleaner, filter the dust in flue gas, heavy metal and desulfurizing agent further, filter the dust produced and lead dust is stored in the ash bucket of cleaner unit, by humidifier, dust and lead dust are humidified at regular time and quantity；

Step 6: the flue gas after dedusting is sent in chimney and discharged through chimney again。

As the preferred technical solution of the present invention, described step 3 sprays into the contained Ca in the desulfurizer powder in absorption tower and S molar ratio 1: 1.2～2.2 contained by flue gas。

As the preferred technical solution of the present invention, the flow velocity controlling flue gas in described step 3 is 6～8m/s, controls the straying quatity of the atomized water of water spout, makes temperature in reaction tower be maintained at 80 DEG C～90 DEG C。

The invention has the beneficial effects as follows: relative to prior art, present invention process is reasonable, can effectively remove the harmful components such as the sulfur dioxide sintered in flue gas and dioxin。Apparatus of the present invention structure optimizes further, it is possible to meet technological requirement, and its purifying property is good, efficiency is high, use cost is relatively low。

Accompanying drawing explanation

Fig. 1 is the structural representation of the present invention。

Accompanying drawing identifies: 1, chilling tower；2, sack cleaner is 1.；3, activated coke packed absorber；31, the cleaned filtering layer of activated coke；32, the cleaned filter plate of activated coke；33, water spout；34, Venturi tube；35, electric cleaner；36, desulfurizing agent memorizer；4, sack cleaner is 2.；5, chimney。

Detailed description of the invention

As shown in Figure 1, for sintering the device of flue gas scrubbing CO_2 and dioxin, including be sequentially connected connect chilling tower 1, sack cleaner 2, activated coke packed absorber 3, sack cleaner 4, the cleaned filter plate of activated coke that described activated coke packed absorber 3 is set 32 is divided into upper and lower two parts from middle part, bottom is provided with desulfurizing agent memorizer 36 and water spout 33, and upper inside wall is fitted with dismountable has the cleaned filtering layer 31 of activated coke。

In the present embodiment, sack cleaner 2 and sack cleaner 4 are low-pressure jet pulse bag type dust catcher, it includes support, casing, blowing device, filter bag and pulse control instrument, filter bag is located in casing, the lower end of casing and upper end are respectively equipped with air inlet and air outlet, casing ash-discharging device is arranged below, pulse control instrument is connected with blowing device circuit；Blowing device is arranged on above casing, and blowing device is connected with air compression plant by pipeline, and blowing device includes injection tube, nozzle and electromagnetic valve, and electromagnetic valve is located in injection tube and is connected with described Pulse Width Control instrument circuit。

This sack cleaner adopts Pressure difference feedback formula pulsed electron controller, in the pulse spacing according to cleaner running resistance regulation blowing device voluntarily, makes winding-up number of times reduce to minimum。Realizing the winding-up function of low-pressure, short pulse punching, it is lightweight, take up an area less, cost is low, and efficiency of dust collection is high, stable, dependable performance, easy to maintenance。

In the present embodiment, activated coke packed absorber bottom adopts Venturi tube 34, and Venturi tube 34 is followed successively by circular cone contraction section, cylindrical section and conical expander section from the bottom up；Desulfurizing agent memorizer 36 is arranged at circular cone contraction section；Water spout 33 is arranged at conical expander section, and circular cone contraction section is arranged below electric cleaner 35。The cleaned filter plate 32 of activated coke is semi-spherical shape, and protruding sphere, towards entering flue gas direction, adopts the cleaned filtering layer 32 of activated coke of semi-spherical shape mainly to make dust and noxious substance at semispherical surface, increases filter area, improve filter effect。

Step one: high temperature sintering flue gas sends into chilling tower 1, flue gas makes temperature be rapidly decreased to 110 DEG C～150 DEG C by humidification after entering chilling tower 1；

Step 2: the sintering flue gas through rapid cooling is sent into sack cleaner 2, filters most dust and heavy metal in flue gas, is filtered the dust produced and lead dust is stored in the ash bucket of sack cleaner 2, by humidifier, dust and lead dust are humidified at regular time and quantity；

Step 3: sintering flue gas removing dust enters activated coke packed absorber 3, desulfurizer powder Ca (OH) in the desulfurizing agent memorizer 36 of Venturi tube 34 bottom after processing₂Enter bottom activated coke packed absorber 3, desulfurizing agent mixes with flue gas in absorption tower, in absorption tower, the atomized water of water spout sprays to whole flow of flue gas cross section, and mixed being incorporated in absorption tower of flue gas, desulfurizing agent, water moves upward, sulfur dioxide and desulfurizing agent Ca (OH) simultaneously₂Chemical reaction occurs, and the sulfur dioxide in flue gas is removed；

Step 4: when sintering flue gas filtering layer 31 cleaned by the cleaned filter plate of activated coke 32 in activated coke packed absorber 3 and activated coke, first the dust in flue gas is filtered by activated coke and intercepts；Then the material such as dioxin, sulfur dioxide and heavy metal is by activated coke micro-porous adsorption；Urged by activity coking oxidation or reduce with moisture, oxygen under ADSORPTION STATE at the sulfur dioxide of activated coke micropore surface simultaneously, form dilute sulfuric acid and the water of ADSORPTION STATE；

Step 5: sinter flue gas after filtration and send into sack cleaner 4, filter the dust in flue gas, heavy metal and desulfurizing agent further, filter the dust produced and lead dust is stored in the ash bucket of sack cleaner 4, by humidifier, dust and lead dust are humidified at regular time and quantity；

Step 6: in the flue gas feeding chimney after dedusting, chimney 5 is discharged again。

In the present embodiment, described step 3 sprays into the contained Ca in the desulfurizer powder in absorption tower and S molar ratio 1: 1.2～2.2 contained by flue gas, the flow velocity controlling flue gas in step 3 is 6～8m/s, controls the straying quatity of the atomized water of water spout, makes temperature in reaction tower be maintained at 80 DEG C～90 DEG C。

The present invention is by above-mentioned technique and device purifying sintering flue gas, it is possible to the effectively harmful components such as the sulfur dioxide in elimination sintering flue gas and dioxin, dioxin annual average < 0.5TEQng/m³, SO₂<50mg/Nm³, particulate matter < 2.5mg/Nm³。Purifying property of the present invention is good, efficiency is high, and use cost is relatively low。

Claims

1. the device being used for sintering flue gas scrubbing CO_2 and dioxin, it is characterized in that, described device include being sequentially connected connect chilling tower, sack cleaner, activated coke packed absorber, sack cleaner, the cleaned filter plate of activated coke that described activated coke packed absorber is set is divided into upper and lower two parts from middle part, bottom is provided with desulfurizing agent memorizer and water spout, and upper inside wall is fitted with the cleaned filtering layer of dismountable activated coke。

2. the device for sintering flue gas scrubbing CO_2 and dioxin according to claim 1, it is characterised in that described sack cleaner is low-pressure jet pulse bag type dust catcher。

3. the device for sintering flue gas scrubbing CO_2 and dioxin according to claim 1 and 2, it is characterized in that, described activated coke packed absorber bottom adopts Venturi tube, and described Venturi tube is followed successively by circular cone contraction section, cylindrical section and conical expander section from the bottom up；Described desulfurizing agent memorizer is arranged at circular cone contraction section；Described water spout is arranged at conical expander section, and described circular cone contraction section is arranged below electric cleaner。

4. the device for sintering flue gas scrubbing CO_2 and dioxin according to claim 3, it is characterised in that the cleaned filtering layer of described activated coke is semi-spherical shape, protruding sphere is towards entering flue gas direction。

5. the method for sintering flue gas scrubbing CO_2 and dioxin, it is characterised in that comprise the following steps:

Step 2: bag-type dust removal system will be sent into through rapid cooling containing lead fume, filter most dust and heavy metal in flue gas, filter the dust produced and lead dust is stored in the ash bucket of cleaner unit, by humidifier, dust and lead dust are humidified at regular time and quantity；

Step 3: enter activated coke packed absorber, desulfurizer powder Ca (OH) in the desulfurizing agent memorizer of Venturi tube bottom containing lead fume removing dust after processing₂Enter bottom activated coke packed absorber, desulfurizing agent mixes with flue gas in absorption tower, in absorption tower, the atomized water of water spout sprays to whole flow of flue gas cross section, and mixed being incorporated in absorption tower of flue gas, desulfurizing agent, water moves upward, sulfur dioxide and desulfurizing agent Ca (OH) simultaneously₂Chemical reaction occurs, and the sulfur dioxide in flue gas is removed；

Step 4: when sintering flue gas filtering layer cleaned by the cleaned filter plate of activated coke in activated coke packed absorber and activated coke, first the dust in flue gas is filtered by activated coke and intercepts；Then the material such as dioxin, sulfur dioxide and heavy metal is by activated coke micro-porous adsorption；Urged by activity coking oxidation or reduce with moisture, oxygen under ADSORPTION STATE at the sulfur dioxide of activated coke micropore surface simultaneously, form dilute sulfuric acid and the water of ADSORPTION STATE；

Step 5: sinter flue gas after filtration and send into bag-type dust removal system, filter the dust in flue gas, heavy metal and desulfurizing agent further, filter the dust produced and lead dust is stored in the ash bucket of cleaner unit, by humidifier, dust and lead dust are humidified at regular time and quantity；

6. the method for sintering flue gas scrubbing CO_2 and dioxin according to claim 5, it is characterised in that spray into the contained Ca in the desulfurizer powder in absorption tower and S molar ratio 1: 1.2～2.2 contained by flue gas in described step 3。

7. the method for sintering flue gas scrubbing CO_2 and dioxin according to claim 5, it is characterized in that, the flow velocity controlling flue gas in described step 3 is 6～8m/s, controls the straying quatity of the atomized water of water spout, makes temperature in reaction tower be maintained at 80 DEG C～90 DEG C。