CN201195098Y - Flue-gas desulfurizing device of sintering device - Google Patents

Abstract

The utility model discloses a flue gas desulfurization device for a sintering machine, which comprises a first-level dust remover, a circulating reactor and a second-level dust remover which are connected in sequence through a flue. The flue gas inlet of the first-level dust remover is connected with the flue gas outlet of the sintering machine; at least one water injector is arranged between the flue gas outlet of the first-level dust remover and the flue gas inlet of the circulating reactor; the flue gas outlet of the circulating reactor is connected with the flue gas inlet of the second-level dust remover; the circulating ash outlet of the second-level dust remover is connected with the circulating ash inlet of the circulating reactor through a recycle transporting device; and the flue gas outlet of the second-level dust remover is connected with a chimney or air through a blower fan. The utility model has compact and simple structure, little investment and low operating cost, and is very suitable for the working conditions that the concentration of sulfur dioxide is low, and the undulation of the sulfur dioxide content and humidity are larger in the flue gas of the sintering machine.

Description

Sintering machine flue gas desulfurization device

technical field

The utility model relates to equipment for removing sulfur dioxide in flue gas, in particular to a sintering machine flue gas desulfurization device.

Background technique

Sulfur dioxide gas pollution control is one of the key environmental protection issues that the world is concerned about. Sulfur dioxide gas pollution is extremely harmful to my country's ecological environment, and has become a top priority for my country's air pollution control. The flue gas emitted by the sintering machines of iron and steel enterprises is one of the main sources of sulfur dioxide pollution. According to relevant literature reports, an iron and steel enterprise with an annual output of 3 million tons will emit 2.2 kilograms of sulfur dioxide for every ton of crude steel produced, of which one ton is produced. Sulfur dioxide emitted by screening sintered ore reaches 1.5 kg. Therefore, how to eliminate and reduce the emission of sulfur dioxide in the flue gas of the sintering plant is a major problem that needs to be solved urgently.

At present, the limestone-gypsum desulfurization process is the main flue gas desulfurization technology, supplemented by other wet and dry desulfurization processes. Traditional flue gas desulfurization equipment is effective in treating power plant boiler flue gas with high concentration of sulfur dioxide, but its equipment is huge, covers a large area, complex technology, high investment and operating costs. The flue gas of the sintering machine has its own characteristics. The concentration of sulfur dioxide in the flue gas is low. When the sintering raw materials are different, the sulfur content in the flue gas of the sintering machine is also very different. The sulfur dioxide in the flue gas exhausted by different sintering machines The concentration of the flue gas can even vary by an order of magnitude; and the composition of the flue gas varies with the operating conditions, and the sulfur dioxide content and humidity fluctuate greatly. The above reasons lead to the fact that the existing flue gas desulfurization equipment of power plant boilers cannot be directly applied to the flue gas treatment of sintering machines, and the existing site conditions of sintering plants do not allow the construction of complex desulfurization devices. Therefore, there has been no suitable desulfurization equipment for sulfur dioxide emissions from sintering machine flue gas in my country's iron and steel metallurgical industry. The past emission reduction measures mainly stayed in the selection of low-sulfur raw materials. Solving the problem can not meet the requirements of the iron and steel enterprises for the total control of sulfur dioxide emissions.

In order to solve the above problems, scientific and technical personnel have carried out some beneficial research on sintering flue gas desulfurization technology and devices. For example, the Chinese invention patent application publication with the publication number CN1442228A introduces "A Process for Purifying Sulfur Dioxide in Flue Gas Using Honeycomb Ceramics" Method", although it has the advantages of high desulfurization efficiency, but the flue gas resistance in this process is very large, and the energy consumption is high. The Chinese Invention Patent Application Publication No. CN101024143A introduces "A Method and Device for Cyclic Enrichment and Desulfurization of Sintering Flue Gas", which achieves the purpose of enriching sulfur dioxide through the recycling of part of the sintering flue gas, but the flue gas of this method In the cycle process, high-concentration oxygen needs to be supplemented to the sintering machine to ensure combustion, and the high-concentration oxygen comes from the separation of air, which is expensive, resulting in extremely high operating costs for this method, and it is still unable to be applied industrially. The announcement number is CN2813075Y. The Chinese utility model patent specification introduces a "sintering head flue gas desulfurization device". Accumulation is not conducive to the smooth flow of flue gas, and even affects the safe operation of the entire desulfurization device.

Contents of the invention

The purpose of this utility model is to provide a sintering machine flue gas desulfurization device with simple and compact structure, low investment and operating costs, and can adapt to working conditions such as low sulfur dioxide concentration in the sintering machine flue gas, large fluctuations in sulfur dioxide content and humidity.

In order to achieve the above purpose, the flue gas desulfurization device of the sintering machine designed by the utility model includes a primary dust collector, a circulating reactor and a secondary dust collector connected in sequence through the flue, and the flue gas inlet of the primary dust collector is connected to the The flue gas outlet of the sintering machine is connected, and at least one water spray device is arranged between the flue gas outlet of the primary dust collector and the flue gas inlet of the circulation reactor, and the flue gas outlet of the circulation reactor is connected to the secondary dust removal The flue gas inlet of the secondary dust collector is connected, the circulating ash outlet of the secondary dust collector is connected with the circulating ash inlet of the circulating reactor through a recirculation conveying device, and the flue gas outlet of the secondary dust collector is connected to the chimney or the atmosphere through a booster fan. connected.

Further, a flue gas recirculation channel is provided between the outlet of the booster fan and the flue gas inlet of the circulation reactor. When the desulfurization device is operating under normal load, the flue gas recirculation channel can be closed; when the desulfurization device processes a small amount of flue gas, the flue gas recirculation channel can be opened to ensure the safe operation of the desulfurization device under low load.

Further, the water spray device is provided with two to three stages. When dealing with a large amount of flue gas, it is necessary to use multi-stage water spraying to ensure that the flue gas and water mist are evenly mixed, so that the sulfur dioxide gas in the flue gas and water undergo a rapid gas-liquid two-phase chemical reaction to generate sulfurous acid.

Further, the circular reactor adopts a straight cylindrical structure, and its cross section is circular, square or rectangular, and its cross-sectional area is 1.0-1.5 times the cross-sectional area of the flue connected to it. It has a simple and compact structure, low operating cost, suitable for small flow of flue gas to pass through, and is conducive to the rapid liquid-solid two-phase chemical reaction between the sulfurous acid generated in the flue gas and the absorbent particles to form calcium sulfite crystals, thereby realizing Flue gas desulfurization.

The utility model has the advantage that: the water spray device arranged between the flue gas outlet of the first-stage dust collector and the flue gas inlet of the circulating reactor can divide the desulfurization reaction of the flue gas into two stages: the flue gas near the water spray device In the reactor, SO ₂ in the flue gas reacts with H ₂ O to generate H ₂ SO ₃ ; in the circulation reactor, the H ₂ SO ₃ in the flue gas reacts with calcium-based absorbent particles to generate CaSO ₃ ·1/2H ₂ O. The above two stages of reaction are respectively gas-liquid two-phase chemical reaction and liquid-solid two-phase chemical reaction. The process is simple, the reaction speed is fast, the reaction efficiency is high, and the desulfurization effect is good. At the same time, the water spray device can ensure that the flue gas entering the circulating reactor has an appropriate temperature and humidity to meet the good environmental conditions for the desulfurization reaction. In particular, the setting of the multi-stage water spray device is conducive to the precise adjustment of flue gas temperature and humidity, ensuring the uniform mixing of flue gas and water mist, creating the best reaction conditions for flue gas desulfurization, and achieving the best desulfurization effect. In this way, the height of the circulating reactor can be appropriately reduced, making the overall structure more compact, especially suitable for working conditions where the sulfur dioxide concentration in the flue gas of the sintering machine is low, and the sulfur dioxide content and humidity fluctuate greatly. At the same time, the first-stage dust collector of the utility model The flue gas inlet is directly connected to the flue gas outlet of the sintering machine, and the equipment occupies a small area, which is very suitable for the small area of the sintering machine factory, and the investment and operation costs are very low.

Description of drawings

The accompanying drawing is a schematic diagram of the structure and principle of a sintering machine flue gas desulfurization device.

Detailed ways

The sintering machine flue gas desulfurization device of the present invention will be further described in detail in conjunction with the accompanying drawings:

The flue gas desulfurization device of the sintering machine shown in the figure is mainly composed of a first-stage dust collector 2, an induced draft fan 3, a circulation reactor 12, a second-stage dust collector 11, a booster fan 10 and a chimney 9, which are connected in sequence through the flue and valves. and other components. The first-stage dust collector 2 adopts an electrostatic precipitator to remove dust particles mixed in the flue gas, and its dust removal efficiency is required to reach more than 90%, so as to ensure that the flue gas entering the circulating reactor 12 contains very little dust and improve the flue gas efficiency. The effective contact area with water and absorbent particles. The secondary dust collector 11 adopts a bag filter to remove the product particles after the flue gas desulfurization reaction, and its dust removal efficiency is required to be over 99%, so as to remove the dust particles in the flue gas to the greatest extent.

The flue gas inlet of the first-stage dust collector 2 is connected with the flue gas outlet of the sintering machine 1, the flue gas outlet of the first-stage dust collector 2 is connected with the flue gas inlet of the circulation reactor 12 through the induced draft fan 3, and the water spray device 4 is set in the circulation The flue gas from the reactor 12 is on the flue before the inlet. The water spraying device 4 is preferably provided with two to three levels. The water spraying device 4 at each level has a plurality of water spray nozzles to accurately control the water spray volume and water spray range, thereby accurately adjusting the temperature and humidity of the flue gas, and providing a good environment for the flue gas. Desulfurization creates optimal reaction conditions.

The circular reactor 12 is a straight cylindrical structure with a circular or square cross-section, and its cross-sectional area is designed to be 1.2 times the cross-sectional area of the flue connected to it. It has the advantages of small and compact structure, integrated with the flue, suitable for the passage of small flow flue gas, and conducive to rapid desulfurization reaction. The absorbent storage bin 13 is connected with the absorbent inlet of the circulation reactor 12 through a feeder 14 . Carbide slag or slaked lime can be used as the absorbent, preferably industrial waste carbide slag, which can turn waste into treasure, is conducive to the development of circular economy, and can also significantly reduce the investment and operating costs of desulfurization equipment. The flue gas outlet of the circulating reactor 12 is connected with the flue gas inlet of the secondary dust collector 11 , and the circulating ash outlet of the secondary dust collector 11 is connected with the circulating ash inlet of the circulating reactor 12 through the recirculating conveying device 6 . A Venturi device 5 is arranged at the flue gas inlet of the circulation reactor 12 , and the circulation ash inlet of the circulation reactor 12 is arranged at the upper part of the Venturi device 5 . The flue gas outlet of the secondary dust collector 11 is connected with the chimney 9 through the booster fan 10 . A flue gas recirculation channel 8 is provided between the outlet of the booster fan 10 and the flue gas inlet of the circulation reactor 12, which can be opened according to the requirements of the operating load.

The working principle of the utility model is as follows: the flue gas produced by the sintering machine 1 enters the primary dust collector 2 to remove more than 90% of the dust in the flue gas. The flue gas after dedusting is sent to the flue gas inlet of the circulating reactor 12 through the induced draft fan 3. Under the action of the water mist of the water spray device 4, the temperature of the flue gas drops to about 70°C, and the relative humidity of the flue gas reaches 40%. Left and right, SO ₂ in the flue gas reacts with H ₂ O in two phases of gas and liquid to generate H ₂ SO ₃ , and at the same time creates good reaction conditions for the subsequent chemical reaction in the circulation reactor 12 . When the amount of flue gas is large, multi-stage water spraying is required to ensure the uniform mixing of flue gas and water mist.

In the circulation reactor 12 , the wet flue gas enters through the lower part of the Venturi device 5 , the circulating ash is fed in from the upper part of the Venturi device 5 , and the calcium-based absorbent is fed in from the absorbent storage bin 13 through the feeder 14 . The Venturi device 5 can increase the flue gas velocity and increase the degree of flue gas turbulence. The high-speed flowing wet flue gas forms a multiphase turbulent flow with the mixture of circulating ash and fresh calcium-based absorbent particles, fully contacting, _H2SO3 in the flue gas and calcium-based absorbent particles undergo a liquid- _solid two-phase chemical reaction to form a solid CaSO ₃ ·1/2H ₂ O.

The flue gas then carries the product particles into the secondary dust collector 11 to remove more than 99% of the ash particles in the flue gas. Most of the calcium-containing circulating ash captured by the secondary dust collector 11 is sent from the upper part of the Venturi device 5 to the circulating reactor 12 through the recirculating conveying device 6, and is repeatedly fully contacted with the moist flue gas to undergo a chemical reaction. The cycle is endless. A small part is sent into the waste residue bin 7 through its desulfurization waste residue outlet.

When the utility model operates under normal load conditions, the recirculation channel 8 can be closed; when the utility model handles a small amount of flue gas, the recirculation channel 8 needs to be opened to ensure the safe operation of the desulfurization system under low load conditions .

Claims (6)

1. A sintering machine flue gas desulfurization device, comprising a first-stage deduster (2), a circulating reactor (12) and a second-stage deduster (11) connected successively through a flue, characterized in that: said first-stage deduster The flue gas inlet of the device (2) is connected with the flue gas outlet of the sintering machine (1), and at least one stage water spraying device (4), the flue gas outlet of the circulating reactor (12) is connected with the flue gas inlet of the secondary dust collector (11), and the circulating ash outlet of the secondary dust collector (11) is passed through the recirculation The conveying device (6) is connected with the circulating ash inlet of the circulating reactor (12), and the flue gas outlet of the secondary dust collector (11) is connected with the chimney (9) or the atmosphere through a booster fan (10). 2. The flue gas desulfurization device for sintering machine according to claim 1, characterized in that: a flue gas recirculation channel is arranged between the outlet of the booster fan (10) and the flue gas inlet of the circulation reactor (12) (8). 3. The sintering machine flue gas desulfurization device according to claim 1 or 2, characterized in that: a Venturi device (5) is arranged at the flue gas inlet of the circulation reactor (12), and the circulation reactor ( 12) The circulating ash inlet is arranged on the top of the Venturi device (5). 4. The flue gas desulfurization device for sintering machine according to claim 1 or 2, characterized in that the water spraying device (4) is provided with two to three stages. 5. The sintering machine flue gas desulfurization device according to claim 1 or 2, characterized in that: the first-stage dust collector (2) is an electrostatic precipitator, and the second-stage dust collector (11) is a bag filter. 6. The flue gas desulfurization device for sintering machine according to claim 1 or 2, characterized in that: the circulating reactor (12) adopts a straight cylindrical structure, and its cross-section is circular, square or rectangular, and its cross-sectional area is It is 1.0 to 1.5 times the cross-sectional area of the connected flue.

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