CN209475965U - Ultralow-temperature denitration device combined with lime-gypsum desulfurization process - Google Patents

Abstract

The utility model discloses an ultra-low temperature denitration device combined with a lime-gypsum desulfurization process, comprising a desulfurization tower with a smoke inlet pipe connected to one side and a circulation tank arranged in the tower bottom, a denitration tower connected to a denitration circulation pump and connected to the top of the desulfurization tower through a pipeline, a denitration agent storage tank connected to a denitration agent pump and an oxidation fan connected to an oxidation air duct connected to the bottom of the circulation tank, a calcium-based desulfurization agent liquid in the circulation tank, pipelines connecting the two sides of the circulation tank to a reduction circulation pump and a desulfurization circulation pump connected to a desulfurization sprayer in the desulfurization tower, a demister, a chimney connected to the top of the denitration tower, a denitration sprayer connected to the denitration circulation pump and a reduction sprayer connected to the reduction circulation pump in the denitration tower in sequence from the bottom to the top of the tower, and one side of the bottom of the denitration tower is connected to the denitration agent pump; the utility model combines the lime-gypsum desulfurization process and the bottom temperature denitration technology, has a simple structure, reasonably utilizes desulfurization products for denitration, reduces costs, and simultaneously improves the synchronous desulfurization rate and the denitration rate.

Description

An ultra-low temperature denitrification device combined with lime-gypsum desulfurization process

technical field

The utility model relates to the technical field of flue gas purification, in particular to an ultra-low temperature denitrification device combined with a lime-gypsum desulfurization process.

Background technique

The flue gas denitrification of industrial furnaces is an environmental protection policy proposed and promoted by the state in recent years. It is in the stage of development and exploration; at present, SNCR and SCR methods are usually used for denitrification of industrial furnace flue gas; SNCR denitrification is to spray ammonia, urea and other reducing agents into the boiler furnace to select NOx under the condition of no catalyst However, reducing agent must be added in the high temperature area. This technology is greatly affected by the size of the boiler structure, and the denitrification rate is low; SCR denitrification refers to the reduction agent (liquid ammonia) and The nitrogen oxides in the flue gas react to generate harmless nitrogen and water, thereby removing NOx in the flue gas. The denitrification efficiency of the SCR method can reach 70-90%. , The flue gas temperature of the blowing furnace and coke oven is below 200°C. If the temperature after wet desulfurization is lower than 60°C, if the SNCR and SCR denitrification methods are used, the flue gas needs to be heated. Greatly increased operating costs.

The limestone/lime-gypsum flue gas desulfurization process uses calcium-based desulfurizers to absorb sulfur dioxide to produce two desulfurization products, calcium sulfite and calcium sulfate. However, the utilization rate of these two desulfurization products is not high and their solubility is small , it is easy to form fouling in the desulfurization absorption tower, leading to blockage, easy to cause waste of desulfurization products and affect the normal operation of the desulfurization system.

Utility model content

Aiming at the deficiencies of the existing technology, the purpose of this utility model is to provide an ultra-low temperature denitrification device combined with the lime-gypsum desulfurization process, which has the advantages of low operating cost and simultaneous high desulfurization and denitrification.

In order to achieve the above object, the utility model provides the following technical solutions:

An ultra-low temperature denitration device combined with a lime-gypsum desulfurization process, comprising a desulfurization tower, a denitration tower, a denitration agent storage tank and an oxidation fan, the top of the desulfurization tower is connected to the bottom of the denitration tower through a pipeline, and the desulfurization One side of the bottom of the tower is connected with a smoke inlet pipe, and there is a circulation tank with a calcium-based desulfurizer liquid in the bottom of the desulfurization tower. The oxidation fan is connected with an oxidation air pipe, and the oxidation air pipe is far away from the One end of the oxidation fan is connected to the tank bottom of the circulation tank, a desulfurization circulation pump is connected to a pipeline on one side of the circulation tank, and a side of the desulfurization circulation pump away from the circulation tank is connected to several layers located in the desulfurization tank. The desulfurization sprayer in the tower, the other side of the circulation tank is connected to the reduction circulation pump, and the direction from the bottom to the top of the denitrification tower is connected with a denitrification sprayer, a reduction sprayer, a demister device and chimney, the reduction circulation pump is connected with the reduction sprayer, the denitration tower bottom side is connected with a denitration circulation pump, the denitration circulation pump is connected with the denitration sprayer, and the denitration agent The storage tank is connected with a denitration agent pump, the bottom side of the denitration tower is connected with the denitration agent pump, and the chimney is connected with the top of the denitration tower.

In this way, the industrial flue gas containing SO ₂ and NO _X enters the desulfurization tower through the smoke inlet pipe connected to the bottom side of the desulfurization tower; the calcium-based desulfurizer in the circulation tank at the bottom of the desulfurization tower is transferred The liquid is transported to the desulfurization sprayer through the pipeline to contact with the industrial flue gas containing SO2 and NO _X for desulfurization reaction _{; 2.} Get a more sufficient reaction to achieve the effect of improving the desulfurization rate; the calcium sulfite produced by the desulfurization reaction enters the circulation tank, and the calcium sulfite reacts with the oxygen sent by the oxidation air pipe connected to the oxidation fan to generate calcium sulfate. The calcium sulfate liquid is transported to the reduction sprayer through the reduction circulation pump; then, the flue gas after the desulfurization is completed enters the bottom of the denitration tower from the top of the desulfurization tower through the pipeline, and is transported from the denitration agent storage tank by the denitration agent pump. The denitrification agent goes to the bottom of the denitrification tower, and then is transported to the denitrification sprayer by the denitrification circulating pump to contact with the flue gas for denitrification reaction; the flue gas that has completed the denitrification reaction enters the reduction sprayer at the upper end of the denitrification tower and the demister in turn for reaction , the calcium sulfate in the liquid transported to the reduction sprayer by the reduction circulation pump first reacts with the nitrogen and sulfur dioxide in the flue gas to generate calcium nitrite, H ₂ O and calcium sulfate respectively, and after further purification by the demister, pass through The straight chimney discharges up to the standard, so as to achieve further desulfurization and denitrification, and then realize the effect of improving the denitrification rate and desulfurization rate; the combination of lime-gypsum desulfurization technology and bottom temperature denitrification technology can be used at temperatures below 90 °C. The removal of nitrogen oxides can be completed without flue gas temperature limitation, which improves the stability of the system; and the overall structure is simple, and the desulfurization product is rationally used as the denitrification reducing agent, which avoids the influence of calcium sulfate scaling on the operation of the desulfurization system and reduces the While reducing the cost, the desulfurization rate and denitrification rate are improved; in addition, the gas-liquid closed internal circulation in the whole production process will not produce new three wastes and no secondary pollution.

It is further provided that: the end of the smoke inlet pipe close to the circulation tank is connected with a vortex gas distributor.

In this way, through the vortex gas distributor connected to the end of the smoke inlet pipe close to the circulation tank, the vortex gas distributor is used to change the way of flue gas, improve the contact mode of flue gas and desulfurization liquid, and further improve the utilization of desulfurization agent rate and denitrification efficiency.

It is further provided that: an air-rising cap is arranged between the denitration sprayer and the reduction sprayer, and the air-rising cap is connected to the denitrification tower.

With such an arrangement, the gas-liquid separation of the flue gas reacted with the spray liquid of the denitrification sprayer is realized through the gas-rising cap provided between the denitrification sprayer and the reduction sprayer.

Further setting: it also includes a lime silo, a preparation tank, a water pool and a lime milk pump, the output end of the lime silo is connected with a discharge valve, and the discharge valve is connected to the notch pipeline of the preparation tank, and the water pool is connected to the The notch opening of the preparation tank is connected with pipelines, the tank bottom of the preparation tank is connected with the milk of lime pump with pipelines, and the milk of lime pump is connected with the circulation tank with pipelines.

In this way, the discharge valve connected to the output end of the lime silo is opened, the lime in the lime silo enters the preparation tank through the pipeline, and the lime entering the preparation tank is mixed with the water injected into the pool connected to the notch of the preparation tank through the pipeline to make lime milk The milk of lime enters the circulation tank through the milk of lime pump connected to the bottom of the preparation tank through pipelines; the preparation of calcium-based desulfurizer is realized, and the purchase cost of desulfurizer is reduced.

Further setting: a stirring device is arranged in the preparation tank.

With such arrangement, the stirring device arranged in the preparation tank can make the lime fully contact with the water, so as to improve the preparation efficiency of milk of lime.

Further setting: a filter is connected between the preparation tank and the milk of lime pump.

Such setting, through the filter connected between the preparation tank and the milk of lime pump, can prevent the milk of lime pump from clogging, and at the same time improve the preparation purity of the desulfurizer.

Further setting: it also includes a collection tank, the bottom of the denitrification tower is connected to the collection tank pipeline, and the bottom of the circulation tank is connected to the collection tank pipeline.

In this way, the denitrification products produced by the denitrification reduction reaction enter the collection pool from the bottom of the denitration tower through the pipeline, and the reactants produced by the desulfurization reaction enter the collection pool through the pipeline, so as to realize the function of collecting desulfurization products and denitration reduction products, avoiding desulfurization products and The blockage of calcium sulfate in the denitrification reduction product affects the operation of the desulfurization tower and the denitrification tower.

Further setting: the pipeline of the collection tank is connected with a filter feed pump, and the end of the filter feed pump far away from the collection tank is connected with a cyclone, and the output end of the cyclone is connected with a filter. A feed pipe is connected between the filter and the desulfurization tower, and a gas-water separator is connected to one end of the filter near the feed pipe, and the input end of the cyclone is connected to the feed pipe. A circulation pipe is connected between the pipes.

In this way, the desulfurization products and denitrification products enter the collection tank and are transported through the filter feed pump pipeline to the cyclone connected to the end of the filter feed pump away from the collection tank, and the denitrification products and desulfurization products are initially cyclone Then the separated solids are sent to the filter connected to the output end of the cyclone and the gas-water separator connected to the filter for secondary separation and tertiary separation and dehydration respectively, and the gypsum by-product is separated; the liquid is passed through the filter After the gas-water separator, it enters the cyclone for secondary cyclone separation through the circulation pipe connected between the input end of the cyclone and the feeding pipe, and the separated liquid returns to the desulfurization tower to continue to participate in the desulfurization reaction, further improving The quality of the desulfurizer entering the circulation tank; and then realize the function of improving the utilization rate of desulfurization and denitrification products, reducing costs, and rationally recycling desulfurization and denitrification products to increase the desulfurization rate.

Further setting: the oxidation blower is a Roots blower.

In this way, the oxidation fan adopts Roots blower, which can save energy and reduce consumption.

Further setting: the desulfurization tower is provided with two layers of primary demisters.

In this way, the flue gas in the desulfurization tower can be preliminarily purified through the two-layer primary demister installed in the desulfurization tower.

In summary, the utility model combines the lime-gypsum desulfurization process with the bottom temperature denitrification technology, and can complete the removal of nitrogen oxides at a temperature lower than 90°C, without being limited by the flue gas temperature, and improves the System stability and denitrification rate; by using the oxidation fan to oxidize calcium sulfite to calcium sulfate and desulfurize with lime-gypsum to produce calcium sulfate as a denitrification reducing agent, improve the utilization rate of desulfurization products and avoid calcium sulfate scaling affecting the operation of the desulfurization system , reduce operating costs, and increase desulfurization and denitrification rates; in addition, the gas-liquid closed internal circulation during the entire production process will not produce new three wastes and no secondary pollution.

Description of drawings

Fig. 1 is a schematic structural view of an embodiment of the utility model.

In the figure: 1. Desulfurization tower; 2. Denitrification tower; 3. Denitrification agent storage tank; 4. Oxidation fan; 5. Smoke inlet pipe; 6. Circulation tank; 7. Oxidation air duct; Desulfurization sprayer; 10. Reduction circulation pump; 11. Denitration sprayer; 12. Reduction sprayer; 13. Demister; 14. Chimney; 15. Denitration circulation pump; 16. Denitration agent pump; 18. Lifting gas cap; 19. Lime bin; 20. Preparation tank; 21. Pool; 22. Lime milk pump; 23. Discharge valve; 24. Stirring device; 25. Filter; 26. Collection Pool; 27. Filter feeding pump; 28. Cyclone; 29. Filter; 30. Delivery pipe; 31. Air-water separator; 32. Circulation pipe; 33. Primary demister.

Detailed ways

Below in conjunction with accompanying drawing and embodiment, the specific embodiment of the utility model is described in further detail. The following examples are used to illustrate the utility model, but not to limit the scope of the utility model.

A kind of ultra-low temperature denitrification device combined with lime-gypsum desulfurization process of the present utility model, as shown in Figure 1, comprises desulfurization tower 1, denitrification tower 2, denitrification agent storage tank 3 and oxidation blower 4, the tower top of desulfurization tower 1 and The bottom of the denitrification tower 2 is connected by a pipeline, the denitrification agent storage tank 3 is connected with a denitrification agent pump 16 , and the bottom side of the denitrification tower 2 is connected with the denitrification agent pump 16 .

As shown in Figure 1, the side of the bottom of the desulfurization tower 1 is connected with a smoke inlet pipe 5, and the end of the smoke inlet pipe 5 close to the circulation tank 6 is connected with a vortex gas distributor 17; Fogger 33; the bottom of the desulfurization tower 1 is provided with a circulation tank 6 in which a calcium-based desulfurizer liquid is placed. One side of the circulation tank 6 is connected to a desulfurization circulation pump 8, and the other side of the circulation tank 6 is connected to a reduction cycle. Pump 10; the side of desulfurization circulation pump 8 far away from circulation tank 6 is connected with several layers of desulfurization sprayers 9 located in desulfurization tower 1; It is connected with the tank bottom of the circulation tank 6; the oxidation blower 4 is a Roots blower.

As shown in Figure 1, the denitrification tower 2 is connected in sequence from the bottom to the top of the tower with a denitrification shower 11, a reduction shower 12, a demister 13 and a chimney 14, a reduction circulation pump 10 and a reduction shower. 12 connection, the bottom side of the denitrification tower 2 is connected with a denitrification circulation pump 15, and the denitration circulation pump 15 is connected with the denitration sprayer 11; The gas lift cap 18 is connected in the denitrification tower 2 , and the chimney 14 is connected with the bottom of the denitrification tower 2 .

As shown in Figure 1, also comprise lime bin 19, preparation tank 20, pool 21 and lime milk pump 22; The pool 21 is connected with the notch pipeline of the preparation tank 20; the stirring device 24 is arranged in the preparation tank 20; the tank bottom of the preparation tank 20 is connected with the milk of lime pump 22 pipelines; Filter 25; milk of lime pump 22 is connected with circulation tank 6 pipelines.

As shown in Figure 1, it also includes a collection tank 26, the tower bottom of the denitrification tower 2 is connected to the collection tank 26 pipelines, and the tank bottom of the circulation tank 6 is connected to the collection tank 26 pipelines; the collection tank 26 pipelines are connected to the filter feed pump 27 The filter feeding pump 27 is connected to a cyclone 28 away from the collection tank 26; the output end of the cyclone 28 is connected to a filter 29, and a feed pipe 30 is connected between the filter 29 and the desulfurization tower 1; An air-water separator 31 is connected to the end of the filter 29 close to the feed pipe 30 ; a circulation pipe 32 is connected between the input end of the cyclone 28 and the feed pipe 30 .

Working principle: The industrial flue gas containing SO ₂ and NO _X enters the desulfurization tower 1 through the smoke inlet pipe 5 connected to the bottom side of the desulfurization tower 1; the desulfurization circulating pump 8 will open the circulation tank 6 at the bottom of the desulfurization tower 1 The calcium-based desulfurizer liquid inside is transported to the desulfurization sprayer ₉ through pipelines to contact with the industrial flue gas containing SO2 and _NOx for desulfurization reaction; the desulfurization sprayer 9 is provided with several layers to facilitate the desulfurization sprayer _The SO2 in the desulfurization liquid and the flue gas can be more fully reacted to achieve the effect of increasing the desulfurization rate; the calcium sulfite produced by the desulfurization reaction enters the circulation tank 6, and the calcium sulfite is sent out through the oxidation air pipe 7 connected to the oxidation fan 4 Oxygen reacts to generate calcium sulfate, and the calcium sulfate liquid in the circulation tank 6 is transported to the reduction sprayer 12 by the reduction circulation pump 10; then, the flue gas after desulfurization is completed enters the denitrification tower 2 from the top of the desulfurization tower 1 through a pipeline. After the bottom of the tower, the denitration agent delivered from the denitration agent storage tank 3 by the denitration agent pump 16 is sent to the bottom of the denitration tower 2, and then sent to the denitration sprayer 11 by the denitration circulation pump 15 to contact with the flue gas for denitration reaction; complete denitration The reacted flue gas passes through the gas-lift cap 18 provided between the denitrification shower 11 and the reduction shower 12 to realize the gas-liquid separation of the flue gas reacted with the spray liquid of the denitrification shower 11; The reduction sprayer 12 entering the upper end of the denitrification tower 2 contacts with the demister 13 for reaction, and the calcium sulfate in the liquid transported to the reduction sprayer 12 by the reduction circulation pump 10 first reacts with the nitrogen and sulfur dioxide in the flue gas respectively. After calcium nitrite, H ₂ O and calcium sulfate are generated, they are further purified by the mist eliminator 13 and discharged up to the standard through the straight chimney 14, so as to achieve further desulfurization and denitrification, and then achieve the effect of improving the denitrification rate and desulfurization rate; The combination of lime-gypsum desulfurization process and bottom temperature denitrification technology can complete the removal of nitrogen oxides at a temperature lower than 90°C, which is not limited by the flue gas temperature and improves the stability of the system; and the overall structure is simple Reasonable use of desulfurization products as denitrification reducing agents avoids calcium sulfate scaling affecting the operation of the desulfurization system, reduces costs and improves desulfurization and denitrification rates; in addition, the gas-liquid closed internal circulation during the entire production process will not produce The new three wastes have no secondary pollution; in addition, the oxidation blower 4 uses a Roots blower to save energy and reduce consumption.

When the calcium-based desulfurizer needs to be prepared, the discharge valve 23 connected to the output of the lime bin 19 is opened, the lime in the lime bin 19 enters the preparation tank 20 through a pipeline, and the lime entering the preparation tank 20 is connected to the preparation tank 20 through a pipeline The water injected into the pool 21 of the notch is mixed to make lime milk, and the lime is fully contacted with water by the stirring device 24 arranged in the preparation tank 20, which is convenient to improve the preparation efficiency of the lime milk; the lime milk is connected to the preparation tank 20 through pipelines The lime milk pump 22 at the bottom of the tank enters the circulation tank 6; and then realizes the preparation of calcium-based desulfurizer, reducing the purchase cost of desulfurizer; in addition, through the filter 25 connected between the preparation tank 20 and the lime milk pump 22, the It can prevent the lime milk pump 22 from clogging, and at the same time improve the preparation purity of the desulfurizer.

In addition, through the vortex gas distributor 17 connected to the end of the smoke inlet pipe 5 close to the circulation tank 6, the vortex gas distributor 17 is used to change the traveling mode of the flue gas, improve the contact mode between the flue gas and the desulfurization liquid, and achieve further improvement in desulfurization. The utilization rate of the agent and the denitrification efficiency; the denitrification product produced by the denitrification reduction reaction enters the collection pool 26 from the bottom of the denitration tower 2 through a pipeline, and the reactant produced by the desulfurization reaction enters the collection pool 26 through a pipeline, so that the desulfurization product and denitration The role of reducing product collection, avoiding the blockage of calcium sulfate in desulfurization products and denitrification reduction products affects the operation of desulfurization tower 1 and denitrification tower 2; the desulfurization products and denitrification products after entering the collection pool 26 are transported to Connected to the cyclone 28 at the end of the filter feed pump 27 away from the collection tank 26, the denitrification product and the desulfurization product are subjected to preliminary cyclone separation through the cyclone 28, and then the separated solids are sequentially sent to the cyclone 28 The filter 29 at the output end and the gas-water separator 31 connected to the filter 29 perform secondary separation and tertiary separation and dehydration to separate gypsum by-products; the liquid separated by the cyclone 28 passes through the filter 29 and the gas-water separator 31 After that, it enters the cyclone 28 again through the circulation pipe 32 connected between the input end of the cyclone 28 and the feed pipe 30 for secondary cyclone separation, and finally the liquid separated from the filter 29 returns to the desulfurization tower 1 Continue to participate in the desulfurization reaction, further improve the quality of desulfurizer entering the circulation tank 6; further realize the function of improving the utilization rate of desulfurization and denitrification products, reducing costs, and rationally recycling desulfurization and denitrification products to improve the desulfurization rate; the utility model also uses DSC The control system is precisely controlled to reduce operating costs while ensuring that the tail gas NOx emission meets the standard.

The above descriptions are only preferred implementations of the present utility model, and the protection scope of the present utility model is not limited to the above-mentioned embodiments, and all technical solutions under the idea of the present utility model all belong to the protection scope of the present utility model. It should be pointed out that for those skilled in the art, some improvements and modifications without departing from the principle of the utility model should also be regarded as the protection scope of the utility model.

Claims (10)

1. An ultra-low temperature denitrification device combined with a lime-gypsum desulfurization process, characterized in that: it comprises a desulfurization tower, a denitrification tower, a denitration agent storage tank and an oxidation blower, and the top of the desulfurization tower passes through the bottom of the denitrification tower Pipeline connection, one side of the bottom of the desulfurization tower is connected with a smoke inlet pipe, the bottom of the desulfurization tower is provided with a circulation tank with a calcium-based desulfurizer liquid inside, the oxidation fan is connected with an oxidation air pipe, The end of the oxidation air pipe far away from the oxidation fan is connected to the bottom of the circulation tank, the side of the circulation tank is connected to a desulfurization circulation pump, and the side of the desulfurization circulation pump away from the circulation tank is connected to a Several layers of desulfurization sprayers are located in the desulfurization tower, the other side of the circulation tank is connected to a reduction circulation pump, and the denitrification tower is sequentially connected with denitration sprayers, reduction Sprayer, mist eliminator and chimney, the reduction circulation pump is connected with the reduction sprayer, the denitration tower bottom side is connected with a denitration circulation pump, the denitration circulation pump is connected with the denitration sprayer The denitration agent storage tank is connected with a denitration agent pump, the bottom side of the denitration tower is connected with the denitration agent pump, and the chimney is connected with the top of the denitration tower. 2. The ultra-low temperature denitrification device combined with lime-gypsum desulfurization process according to claim 1, characterized in that: the end of the smoke inlet pipe close to the circulation tank is connected with a vortex gas distributor. 3. A kind of ultra-low temperature denitrification device combined with lime-gypsum desulfurization process according to claim 1, characterized in that: a gas-lifting cap is arranged between the denitrification shower and the reduction shower, so that The gas lift cap is connected to the denitration tower. 4. A kind of ultra-low temperature denitration device combined with lime-gypsum desulfurization process according to claim 1, characterized in that: it also includes a lime bin, a preparation tank, a water pool and a lime milk pump, and the output end of the lime bin is connected with A discharge valve, the discharge valve is connected to the notch pipeline of the preparation tank, the pool is connected to the notch pipeline of the preparation tank, the tank bottom of the preparation tank is connected to the lime milk pump pipeline, The lime milk pump is connected with the circulation tank pipeline. 5. The ultra-low temperature denitrification device combined with the lime-gypsum desulfurization process according to claim 4, characterized in that: the preparation tank is provided with a stirring device. 6 . The ultra-low temperature denitrification device combined with the lime-gypsum desulfurization process according to claim 4 , characterized in that a filter is connected between the preparation tank and the lime milk pump. 7. A kind of ultra-low temperature denitrification device combined with lime-gypsum desulfurization process according to claim 1, characterized in that: it also includes a collection pool, the bottom of the denitrification tower is connected to the collection pool with pipelines, and the circulation The tank bottom of the tank is connected with the collection tank pipeline. 8. A kind of ultra-low temperature denitrification device combined with lime-gypsum desulfurization process according to claim 7, characterized in that: the pipeline of the collection pool is connected with a filter feed pump, and the filter feed pump is far away from the One end of the collection tank is connected to a cyclone, the output end of the cyclone is connected to a filter, and a feed pipe is connected between the filter and the desulfurization tower, and the filter is close to the feed One end of the pipe is connected with a gas-water separator, and a circulation pipe is connected between the input end of the cyclone and the feeding pipe. 9. The ultra-low temperature denitrification device combined with lime-gypsum desulfurization process according to claim 1, characterized in that: the oxidation blower is a Roots blower. 10. The ultra-low temperature denitrification device combined with the lime-gypsum desulfurization process according to claim 1, characterized in that: the desulfurization tower is provided with two layers of primary demisters.