CN209161975U - Alkali spraying washing tower - Google Patents

Abstract

The utility model discloses an alkali spray washing tower, which comprises a shell (7), and the shell (7) contains an air flow uniform device, an alkali liquid spray device, a demister (3) and an upper part arranged in sequence from bottom to top. The spray device (2) and the water removal device (1), along the vertical direction, the air flow uniform device contains at least one layer of gas grids (5), and the lye spray device contains at least one lye spray layer (16). The alkali spraying washing tower has the functions of washing dust, spraying alkali to remove acid, without adding additional blast furnace gas treatment equipment. Comprehensive treatment of three kinds of gas.

Description

An alkali spray washing tower

technical field

The utility model relates to the field of iron and steel smelting equipment, in particular to an alkali spray washing tower.

Background technique

The long-term gas emitted with the normal production of blast furnace ironmaking includes two parts: one part is the gas discharged from the material tank when charging the top of the furnace, which is called equalizing gas; It's called top gas. When the blast furnace interrupts production and stops air supply due to special reasons, the gas discharged from the top of the furnace is called large-scale gas.

The furnace top pressure-equalizing gas necessary for blast furnace production is discharged into the atmosphere through a cyclone and a muffler before each charging (about 300 times a day to the air). The pressure-equalizing gas contains a large amount of CO and CO. _2. Toxic and combustible mixed gas with dust, the discharge amount of pressure-equalizing gas is 6-8Nm ³ /ton of iron, and the dust content exceeds 10g/Nm ³ . The annual production of molten iron in China is about 700 million tons. The amount of gas discharged into the atmosphere by the pressure and release equipment is as high as 5.5 billion m ³ / year, and the unit price of blast furnace gas is calculated at 0.11 yuan / Nm ³ , the economic loss caused by this part of the gas is about 600 million yuan / year, and the amount of dust discharged reaches 5.5 tons/year. The equal-pressure gas in the blast furnace ironmaking production process is directly discharged into the atmosphere, which not only causes atmospheric pollution, but also wastes energy.

There are many technologies at home and abroad that can realize the recovery of blast furnace top pressure equalization gas, and some have achieved good results, such as Chinese patent CN102031321A, published on April 27, 2011, a kind of "blast furnace top pressure equalization gas" disclosed. Recovery method and recovery device". However, these technologies all need to add special pressure equalizing gas dedusting equipment on the basis of the original blast furnace system, so as to realize the dust removal of the equalizing gas and then recycle it. For most blast furnace systems that need to be retrofitted on the original site, the area of the retrofit process and additional equipment investment are important issues that cannot be avoided.

During the production process of the blast furnace, ironmaking production is sometimes interrupted according to the needs of maintenance and handling of accidents, and planned wind breaks are arranged, such as dealing with damaged cooling walls. At this time, the material surface needs to be lowered to draw water; Production, unplanned wind break. When the blast furnace stops blowing and injecting fuel, the original raw fuel in the blast furnace is not fully reacted. In addition, due to operations such as drawing water on the lowering surface, the composition of the gas discharged at this time is complex, including a large amount of water vapor, large Particulate dust, H ₂ , CH ₄ , CO, CO ₂ , N ₂ . The gas produced after the blast furnace shut-off operation does not meet the recycling requirements due to the characteristics of high humidity, high temperature, complex composition, large dust content, large dust particle size, and easy explosion. For this part of the large-scale emission gas, it is not suitable to use the bag filter in the blast furnace production process for dust removal. There is no good treatment method at home and abroad. The only way to open the furnace top emission valve for large-scale emission treatment is to remove the gas containing a large amount of dust pollutants. The large released gas is directly discharged into the atmosphere, causing serious air pollution.

Many iron and steel enterprises inject bituminous coal or anthracite to different degrees in order to reduce the coke ratio. Some iron and steel enterprises use imported raw materials sprayed with seawater, and some iron and steel enterprises use chlorine-containing additives (CaCl ₂ , etc.) to improve the strength of sintered ore. For the above reasons, the top gas produced by many domestic iron and steel enterprises in the production process contains a large amount of acidic media (chloride ions and sulfate ions).

With the enlargement of blast furnace and the increase of furnace top pressure, the blast furnace gas purification method has been developed from wet to dry. "French bag dust removal process", therefore, dry bag dust collectors are widely used in China to complete the purification of furnace top gas. Dry dust removal can not purify the acidic medium in the top gas, these acidic medium will form a strong acid solution when contacted with water, which will cause serious corrosion to the gas pipeline. "Design Specifications for Blast Furnace Ironmaking Engineering" (GB50427-2015) recommends that "when the content of corrosive substances such as chloride ions in clean gas is high, it is advisable to set up lye spray towers before entering the gas pipeline network of the whole plant to control the content of chloride ions in the gas. facilities”. In response to this situation, many domestic iron and steel enterprises use the soda spray tower as the dechlorination device for the top gas while applying the dry gas dedusting technology. A "blast furnace gas spray alkali dechlorination device".

Blast furnace production requires solving the corrosive problem of top gas in terms of technology, and in environmental protection, it requires solving the problem of dust removal and recovery of pressure-equalized gas, and to solve the problem of dust removal and acid removal of large-spread gas. From the above analysis, it can be seen that the existing technology has no good treatment method for large-scale loose gas, and it is directly discharged to the air; for blast furnace top pressure equalization gas, although the existing technology has provided many recovery methods, but all need to add special The pressure-equalizing gas dust removal equipment of the company faces the important problems of floor space and additional equipment investment in the transformation process. As an alkali spray tower for eliminating acidic medium in coal gas, it only has the single function of spraying alkali to remove acid.

Utility model content

In order to complete the dedusting and deacidification of the large-scale gas, the dedusting and recovery of the pressure-equalizing gas, and the deacidification of the furnace top gas. The utility model provides an alkali spraying washing tower. The alkali spraying washing tower has the functions of washing dust, spraying alkali and removing acid, without adding additional blast furnace gas treatment equipment, and can remove the top gas and pressure-equalizing gas after dry dust removal. And the large-scale gas is directly introduced into the alkali spray washing tower to realize the comprehensive treatment of the three types of gas.

The technical utility model adopted by the utility model to solve the technical problem is as follows: an alkali spray washing tower, including a shell, and the shell contains an air flow uniform device, an alkali liquid spray device, a demister, an upper For the spray device and the water removal device, along the vertical direction, the air flow uniform device contains at least one layer of gas grids, and the alkali liquor spray device contains at least one alkali liquor spray layer.

The alkali spraying washing tower contains a gas inlet, which is located at the lower part of the shell, and the gas flow uniform device is located above the gas inlet. The grids are staggered by a set angle.

The lye spray layer includes long spray guns and short spray guns evenly spaced along the circumferential direction of the casing. The long spray guns and the short spray guns are arranged along the radial direction of the casing.

The lye spray device contains a plurality of lye spray layers, and in two adjacent lye spray layers, the spray directions of the high-pressure atomizing nozzles in one lye spray layer are all upward, and the other The spraying directions of the high-pressure atomizing nozzles in the lye spray layer are all downward.

The lye spray device contains four lye spray layers, and the four lye spray layers are the first lye spray layer, the second lye spray layer, the third lye spray layer in the order from bottom to top. The lye spray layer and the fourth lye spray layer.

The spray directions of the high-pressure atomizing nozzles in the first lye spray layer are all upward, the spray directions of the high-pressure atomizing nozzles in the second lye spray layer are all downward, and the third lye spray layer The spraying directions of the high-pressure atomizing nozzles in the first lye spray layer are all upward, and the spraying directions of the high-pressure atomizing nozzles in the first lye spray layer are all downward.

The upper spraying device includes a plurality of nozzles capable of spraying water flow to the demister, the water removing device is a packing water removing device, and the water removing device is located on the upper part of the shell.

The top of the casing is provided with two gas outlets, the two gas outlets are respectively a first gas outlet and a second gas outlet, the first gas outlet is connected with a release valve, and the second gas outlet is sequentially connected with a first gas outlet Shut-off valves and eliminators.

The bottom of the shell is provided with a sewage outlet, a sewage treatment device is arranged below the sewage outlet, and an inlet pipe is connected outside the gas inlet, and the inlet pipe is provided with a second stop valve, a pressure instrument, a temperature instrument and a flow instrument.

The beneficial effects of the present utility model are:

1. It can complete the washing and dust removal treatment of the pressure-equalized gas, simplify the process flow of the pressure-equalized gas recovery, and reduce the floor space.

2. It can complete the dust removal and acid removal treatment of large scattered gas to reduce air pollution.

3. It can complete the alkali spraying and deacidification treatment of the top gas to reduce the corrosion of the gas pipeline.

4. The alkali spray washing tower has simple structure, low cost and low maintenance cost.

5. The alkali spray washing tower has few moving parts, is not easy to fail, and has a high operation rate.

Description of drawings

The accompanying drawings forming a part of the present application are used to provide further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention.

Fig. 1 is the structural schematic diagram of the alkali spray washing tower of the present invention.

Figure 2 is a schematic structural diagram of an alkali spray layer.

1. Water removal device; 2. Spray device; 3. De-foamer; 4. High-pressure atomizing nozzle; 5. Gas grille; 6. Sewage treatment device; 7. Housing; 8. Drain valve; 9. Section 9. 1. Stop valve; 10. Water remover; 11. Check valve; 12. Clean gas pipe network; 13. Second stop valve; 14. Long spray gun; 15. Short spray gun; 16. Alkali spray layer.

Detailed ways

It should be noted that the embodiments in the present application and the features of the embodiments may be combined with each other in the case of no conflict. The present utility model will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

An alkali spray washing tower includes a shell 7, and the shell 7 contains an air flow uniform device, an alkali liquid spray device, a demister 3, an upper spray device 2 and a water removal device 1 arranged in sequence from bottom to top. In the vertical direction, the air flow uniform device includes at least one layer of gas grids 5, and the lye spray device includes at least one lye spray layer 16, as shown in FIG. 1 .

In this embodiment, the alkali spray washing tower contains a gas inlet, which is located at the lower part of the shell 7 , and the airflow uniform device is located above the gas inlet, and the airflow uniform device contains three layers of gas grids 5 . , the adjacent two layers of gas grids 5 are staggered by a set angle, so that the blast furnace gas entering the tower is evenly distributed on the cross section of the entire tower.

In this embodiment, the lye spray layer 16 includes a plurality of long lances 14 and short lances 15 arranged at uniform intervals along the circumferential direction of the housing 7 , the long lances 14 intersect with the centerline of the housing 7 , the long lances 14 and The short spray guns 15 are all columnar structures, the length of the long spray gun 14 is greater than the length of the short spray gun 15, the long spray gun 14 and the short spray gun 15 are both arranged along the radial direction of the housing 7, that is, the length direction of the long spray gun 14 and the length of the short spray gun 15. The directions are all arranged along the radial direction of the housing 7 , and a plurality of high-pressure atomizing nozzles 4 are provided on both the long spray gun 14 and the short spray gun 15 , as shown in FIG. 2 .

In this embodiment, the lye spray device includes a plurality of lye spray layers 16 spaced along the vertical direction. Among the two adjacent lye spray layers 16, one lye spray layer The spraying directions of the high-pressure atomizing nozzles 4 in 16 are all upward, and the spraying directions of the high-pressure atomizing nozzles 4 of the other lye spray layer 16 are all downward. For example, the lye spray device includes four lye spray layers 16, and the four lye spray layers 16 are the first lye spray layer and the second lye spray layer in order from bottom to top. layer, the third lye spray layer and the fourth lye spray layer.

The spray directions of the high-pressure atomizing nozzles 4 in the first lye spray layer are all upward, and the spray directions of the high-pressure atomizing nozzles 4 in the second lye spray layer are all downward, and the third lye spray The spraying directions of the high-pressure atomizing nozzles 4 in the spray layer are all upward, and the spraying directions of the high-pressure atomizing nozzles 4 in the first lye spray layer are all downward, as shown in FIG. 1 . The bottom of the casing 7 is provided with a sewage outlet, and a sewage treatment device 6 is located below the sewage outlet. The dust-laden sewage produced after the gas is treated by the alkali spray washing tower is treated by the sewage treatment device 6 to obtain sludge and recyclable water.

According to process requirements, a plurality of lye spray layers 16 and their accompanying high-pressure atomizing spray heads 4 are arranged on different heights. After the lye is sprayed from the high-pressure atomizing nozzle 4, an atomized state is formed inside the shell 7 of the caustic spray washing tower, and the atomized caustic lye evenly fills the interior space of the caustic spray washing tower. The high-pressure atomizing nozzle 4 sprays the lye in the high-pressure atomization state to realize the dechlorination treatment of the coal gas.

The acid dust-laden blast furnace gas enters the alkali spray washing tower from the gas inlet on the lower side of the alkali spray washing tower, and under the action of the atomized alkali liquid, the acid removal and dust removal treatment are completed:

1. Alkali spraying and acid removal treatment: The atomized lye that fills the inner space of the spraying alkali washing tower fully reacts with the acidic medium in the gas to eliminate the corrosiveness of the gas.

2. Washing and dedusting treatment: Due to the inertial collision, interception and cohesion between the atomized lye and the gas dust, the larger particles of dust settle with the atomized washing by gravity, and are discharged together with the washing liquid and enter the alkali spraying washing tower The sewage treatment device 6 outside the sewage outlet at the bottom. The dusty sewage can be recycled after being treated by the sewage treatment device 6 at the bottom of the alkali spray washing tower.

In this embodiment, the upper spraying device 2 includes a plurality of nozzles capable of spraying water to the demister 3 , the dewatering device 1 is a packing dewatering device, and the dewatering device 1 is located on the upper part of the casing 7 . The demister 3 can be selected from a wire mesh demister (or other types of high-efficiency demisters such as a folding plate demister), and the demister 3 is arranged in the space above the high-pressure atomizing nozzle 4. The smaller particles of dust and the lye in the atomized state form mist, and the gas with mist rises at a certain speed through the demister 3. The demister 3 completes the treatment of the smaller dust particles in the gas, and obtains a water-containing clean gas. The upper spray device 2 is arranged above the demister 3, and the demister 2 is regularly sprayed and washed with high-pressure water through the upper spray device 2 to prevent the demister 3 from being blocked after long-term use. The acid dust-laden blast furnace gas passes through the action of the atomized lye sprayed by the high-pressure atomizing nozzle 4 and the demister 3, so that the gas with larger water content can be obtained.

In this embodiment, the top of the casing 7 is provided with two gas outlets, and the two gas outlets are a first gas outlet and a second gas outlet respectively. The second gas outlet is connected with a first stop valve 9, a water eliminator 10, a check valve 11 and a clean gas pipe network 12 in sequence, as shown in FIG. 1 .

Above the upper spraying device 2, a packing water removing device 1 is arranged near the top outlet of the alkali spraying washing tower. The inner packing of the packing water removing device 1 can be selected from aluminum alloy rosette packing (or stainless steel rosette packing or other types of packing). When the water-containing gas passes through the packing water removing device 1, the small water droplets in the gas will converge into large water droplets under the action of the packing and realize the preliminary water removal under the action of gravity.

The water eliminator 10 can be a baffle type water eliminator (or other types of high-efficiency water eliminators such as a cyclone type water eliminator). The water-containing gas after the preliminary water removal is discharged from the second gas outlet at the top of the alkali spraying washing tower, and enters the water eliminator 10 arranged on the outside of the top of the alkali spraying washing tower to complete the water removal treatment of the water-containing gas, and finally obtain a gas that meets the requirements of the user. The qualified gas enters the clean gas pipe network 12 through the check valve 11 for the user to use.

There is a relief valve 8 at the top outlet of the alkali spray washing tower, which has the functions of a stop valve and a safety valve at the same time: when the internal pressure of the alkali spray washing tower is normal, the relief valve 8 is in a closed state; when the pressure exceeds the set value, the relief valve 8 Automatic opening reduces internal pressure.

According to the process requirements, the soda spray washing tower can separately process the top gas discharged from the top of the blast furnace in the chemical reaction of the raw fuel and the pressure equalizing gas discharged from the material tank when the top is charged, and can also process the top gas and the uniform pressure at the same time. Press the gas. According to the process requirements, the alkali spray washing tower can handle the large gas emission when the blast furnace is off. When processing the top gas and pressure-equalizing gas whose gas composition meets the recovery requirements, open the first shut-off valve 9 at the top outlet of the alkali spray washing tower, and close the vent valve 8. The treated top gas and pressure-equalizing gas can be recovered normally and enter the net. Gas network 12. When dealing with large scattered gas whose composition does not meet the recovery requirements, close the first shut-off valve 9 at the top outlet of the alkali spray washing tower, open the venting valve 8, and release the gas that meets the emission requirements after dust removal and acid removal into the air.

In this embodiment, the gas inlet is connected with an inlet pipe, and the inlet pipe is provided with a second shut-off valve 13, a pressure instrument, a temperature instrument and a flow instrument. The diameter and height of the shell 7 of the alkali spray washing tower are determined according to the average flow rate of blast furnace gas in the tower. The blast furnace gas comprehensive treatment device proposed by the utility model automatically adjusts the water spray amount of the high-pressure atomizing nozzle 4 by detecting the gas pressure, flow rate and flow rate at the blast furnace gas inlet, so as to improve the acidic dust-containing gas and atomized alkali inside the spraying alkali washing tower. Liquid neutralization reaction and dust removal effect.

The alkali spray washing tower of the utility model has high dust removal efficiency, can remove dust with a particle size of 0.1-20 microns, and the dust content of the treated gas is less than 5 mg/m ³ . The mechanical water content of the water-containing clean gas is less than 7g/m ³ after being processed by the packing water removing device 1 and the water removing device 10 . The top gas and pressure-equalizing gas treated by the alkali spray washing tower proposed by the utility model meet the recovery requirements.

The alkali spraying washing tower proposed by the utility model can realize the comprehensive treatment of three kinds of blast furnace gas: during blast furnace production, it can not only realize the deacidification treatment of the furnace top gas to eliminate its corrosiveness, but also can complete the pressure equalization of the gas. It has the functions of dust removal and recovery; when the blast furnace is off, it can complete the dust removal and acid removal treatment of the large loose gas, and discharge it into the air after meeting the emission requirements.

The gas grid 5, the demister 3, the upper spraying device 2 and the water removing device 1 described in the present utility model can all adopt the existing commercially available products. Therefore, the alkali spray washing tower proposed by the utility model has the advantages of simplicity, low cost, low maintenance cost, few movable parts, less failure to occur, and high operating rate, which can reduce air pollution, realize energy saving, emission reduction and resource recycling.

The above descriptions are only specific examples of the present invention, and cannot limit the scope of implementation of the present invention. Therefore, the replacement of the equivalent components thereof, or the equivalent changes and modifications made according to the scope of the patent protection of the present invention, shall still belong to the scope of the present invention. Scope covered by this patent. In addition, the technical features of the present invention can be freely combined with the technical features, between the technical features and the technical utility model, and between the technical utility model and the technical utility model.

Claims (9)

1. a kind of spray caustic scrubber, which is characterized in that the spray caustic scrubber includes shell (7), in shell (7) containing from it is lower to On the air-flow uniform device, lye spray equipment, demister (3), top spray equipment (2) and the de-watering apparatus (1) that set gradually, Along the vertical direction, the air-flow uniform device contains at least one layer of gas grid (5), and the lye spray equipment contains at least one A lye spraying layer (16).

2. spray caustic scrubber according to claim 1, which is characterized in that the spray caustic scrubber contains gas entry, should Gas entry is located at the lower part of shell (7), and the air-flow uniform device is located at the top of the gas entry, and the air-flow uniformly fills It sets containing multi-layer gas grid (5), the angle for the setting that is staggered between two layers adjacent of gas grid (5).

3. spray caustic scrubber according to claim 1, which is characterized in that lye spraying layer (16) contains along shell (7) The long spray gun (14) and short spray gun (15) of circumferential uniform intervals arrangement, long spray gun (14) and short spray gun (15) are along shell (7) It is arranged radially, is equipped with high-pressure atomization spray head (4) on long spray gun (14) and short spray gun (15).

4. spray caustic scrubber according to claim 3, which is characterized in that the lye spray equipment contains multiple lye sprays Drenching layer (16), in two adjacent lye spraying layers (16), high-pressure atomization spray head (4) in a lye spraying layer (16) All upward, the injection direction of the high-pressure atomization spray head (4) in another lye spraying layer (16) is whole downward for injection direction.

5. spray caustic scrubber according to claim 4, which is characterized in that the lye spray equipment is containing there are four lye to spray Drenching layer (16), four lye spraying layers (16) are followed successively by the first lye spraying layer, the second lye according to order from bottom to top Spraying layer, third lye spraying layer and the 4th lye spraying layer.

6. spray caustic scrubber according to claim 5, which is characterized in that the high-pressure atomization spray in the first lye spraying layer The injection direction of head (4) is whole upward, the injection direction whole court of the high-pressure atomization spray head (4) in the second lye spraying layer Under, the injection direction of the high-pressure atomization spray head (4) in the third lye spraying layer is whole upward, in the first lye spraying layer The injection direction of high-pressure atomization spray head (4) is whole downward.

7. spray caustic scrubber according to claim 1, which is characterized in that top spray equipment (2) containing it is multiple can be to The nozzle of demister (3) injection water, de-watering apparatus (1) are filler de-watering apparatus, and de-watering apparatus (1) is located at the upper of shell (7) Portion.

8. spray caustic scrubber according to claim 1, which is characterized in that it is set at the top of shell (7) there are two gas vent, Two gas vents are respectively first gas outlet and second gas outlet, and first gas outlet is externally connected with diffusion valve (8), second gas outlet is outer is connected with the first shut-off valve (9) and dehydrater (10) in turn.

9. spray caustic scrubber according to claim 2, which is characterized in that the bottom of shell (7) is equipped with sewage draining exit, the blowdown Lower section outside mouthful is equipped with sewage-treatment plant (6), which is externally connected with inlet duct, is provided on the inlet duct Second shut-off valve (13), pressure gauge, thermometric instrument and flow instrument.