Absorption tower for tail gas desulfurization

Abstract

The absorption tower comprises an absorption tower body, the absorption tower body is divided into an upper layer and a lower layer, the lower layer comprises filler and a liquid distribution plate, organic amine liquid evenly flows into the filler through the liquid distribution plate and makes full contact with sulfuric acid tail gas, SO2 in the sulfuric acid tail gas is dissolved in the organic amine liquid, and SO2 in the sulfuric acid tail gas is reduced; the upper layer comprises a liquid collecting plate, a rotational flow ejector, a washing spraying layer, a demister washing spraying layer, a demister and a control turning plate, alkaline washing water passes through the washing spraying layer and the rotational flow ejector, is gathered on the liquid collecting plate and flows back to the washing tank, on one hand, smoke dust in the sulfuric acid tail gas can be washed away, and on the other hand, SO2 in the sulfuric acid tail gas can be further absorbed. The device is suitable for an organic amine system, and realizes ultra-low and ultra-clean emission of sulfuric acid tail gas.

Description

Technical Field

[0001] The utility model belongs to the technical field of SO2 absorption and purification equipment in sulfuric acid tail gas, and specifically relates to an absorption tower used for tail gas desulfurization. Background Art

[0002] The absorption tower is an organic amine system used to treat sulfuric acid tail gas. As the country pays more and more attention to environmental protection, emission standards are becoming increasingly stringent. Sulfuric acid tail gas is treated by an organic amine system, and smoke can no longer meet emission standards, which will directly affect the operation of the entire industrial chain. Utility Model Content

[0003] In view of the deficiencies in the prior art, the purpose of the utility model is to provide an absorption tower for tail gas desulfurization to solve the problem that smoke dust still cannot meet emission standards after the organic amine system treats sulfuric acid tail gas.

[0004] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0005] An absorption tower for tail gas desulfurization, comprising an absorption tower and the absorption tower is divided into an upper and a lower layer;

[0006] The lower layer includes a lower filler and a liquid distribution plate above the lower filler, and the liquid distribution plate is connected to the organic amine liquid inlet;

[0007] The upper layer includes an upper filler, a liquid collecting plate, a swirl ejector, a water washing spray layer, a demister flushing spray layer, a demister and a control flap, which are located above the liquid distributing plate and arranged in sequence from bottom to top; the liquid collecting plate is connected with an alkaline water outlet, the water washing spray layer is connected with an alkaline water inlet, and the demister flushing spray layer is connected with a desalted water inlet;

[0008] A sulfuric acid tail gas inlet is arranged on the lower side wall of the absorption tower below the lower filler; an organic amine liquid outlet is arranged at the bottom of the absorption tower; and a sulfuric acid tail gas outlet is arranged at the top of the absorption tower.

[0009] The utility model also includes the following technical features:

[0010] Specifically, the lower filler is a perforated plate corrugated filler layer with a thickness of 5m and a specific surface area of ​​452m 2 / m 3 .

[0011] Specifically, the liquid distribution plate includes a main tank and multiple sub-tanks below the main tank; multiple liquid distribution holes are evenly distributed at intervals on the lower part of the two side walls of the main tank; the sub-tanks are perpendicular to the main tank, and the liquid distribution holes are evenly distributed at the bottom of the sub-tanks; multiple sub-tanks are evenly distributed at intervals, and the liquid distribution holes of the main tank correspond one to one with the sub-tanks; the organic amine liquid enters the main tank through the organic amine liquid inlet, the liquid distribution holes on the side of the main tank divert the amine liquid to the sub-tanks, and the liquid distribution holes at the bottom of the sub-tanks evenly distribute the amine liquid to the lower filler.

[0012] Specifically, the upper filler is a perforated plate corrugated filler layer with a thickness of 0.5m and a specific surface area of ​​452m 2 / m 3 .

[0013] Specifically, the liquid collecting plate is a trough-shaped plate with multiple grooves for collecting upper alkaline flushing water, the gaps between adjacent grooves are used for the circulation of sulfuric acid tail gas, and an umbrella-shaped baffle is arranged above the gaps between adjacent grooves to prevent the alkaline flushing water from entering the lower amine liquid.

[0014] Specifically, the swirl injector is cylindrical, and the swirl blades are welded with steel plates at the bottom.

[0015] Specifically, the water washing spray layer is a water inlet main pipe connected to multiple thin pipes for diversion, and a glass fiber reinforced plastic nozzle is installed on the thin pipe to evenly distribute the alkaline desalted water into the swirl ejector.

[0016] Specifically, a plastic hose is installed on the water inlet pipe of the mist eliminator flushing spray layer, and the other end of the plastic hose is connected to a polytetrafluoroethylene nozzle, which is installed at the center of the cylindrical mist eliminator to flush the mist eliminator.

[0017] Specifically, the control flap controls five groups of flaps through five electric valves, each group of flaps consists of an axis and multiple circular baffles, and each cylindrical demister has a circular baffle on the top. The flow rate of the sulfuric acid tail gas is controlled by controlling the opening of each group of circular baffles.

[0018] Compared with the prior art, the utility model has the following technical effects:

[0019] The utility model is suitable for an organic amine system and realizes ultra-low and ultra-clean emission of sulfuric acid tail gas.

[0020] The organic amine liquid in the lower layer of the absorption tower of the utility model flows into the filler evenly through the liquid distribution plate, fully contacts with the sulfuric acid tail gas, and circulates to absorb the SO2 in the sulfuric acid tail gas; the alkaline flushing water in the upper layer passes through the water washing spray layer and the swirl ejector, is collected on the liquid collecting plate and refluxes to the water washing tank, which can wash away the smoke in the sulfuric acid tail gas on the one hand, and further absorb the SO2 in the sulfuric acid tail gas on the other hand, thereby realizing ultra-low emission of sulfuric acid tail gas.

[0021] The upper demister of the utility model can remove water mist in sulfuric acid tail gas washed by alkaline water, and the desalted water washes the demister through the demister flushing spray layer, and finally collects on the liquid collecting plate and flows to the water washing tank.

[0022] The utility model has a control flap installed on the upper part of the demister, and the flap opening is controlled according to different working conditions during operation to control the flow rate of sulfuric acid tail gas and improve the dust removal effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0024] Figure 2 The figure is a flow chart of a process for ultra-low and ultra-clean emissions of sulfur-containing tail gas.

[0025] The meaning of each number in the figure is:

[0026] 1. Absorption tower, 2. Lower filler, 3. Liquid distribution plate, 4. Upper filler, 5. Liquid collecting plate, 6. Cyclone ejector, 7. Water washing spray layer, 8. Demister flushing spray layer, 9. Demister, 10. Control flap; 11. Sulfuric acid tail gas inlet, 12. Organic amine liquid outlet, 13. Sulfuric acid tail gas outlet, 31. Organic amine liquid inlet, 51. Alkaline water outlet, 71. Alkaline water inlet, 81. Desalted water inlet. DETAILED DESCRIPTION

[0027] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of the present application fall within the protection scope of the present invention.

[0028] Embodiment 1:

[0029] This embodiment provides an absorption tower for tail gas desulfurization, such as Figure 1 As shown, it includes an absorption tower 1 and the absorption tower 1 is divided into two layers, an upper layer and a lower layer.

[0030] The lower layer includes a lower filler 2 and a liquid distribution plate 3 above the lower filler, and the liquid distribution plate 3 is connected to the organic amine liquid inlet 31; the organic amine liquid can flow into the lower filler evenly through the liquid distribution plate to fully contact with the sulfuric acid tail gas, dissolve the SO2 in the sulfuric acid tail gas in the organic amine liquid, and reduce the SO2 in the sulfuric acid tail gas.

[0031] The upper layer includes an upper filler 4, a liquid collecting plate 5, a cyclone ejector 6, a water washing spray layer 7, a demister flushing spray layer 8, a demister 9 and a control flap 10, which are located above the liquid distribution plate 3 and arranged in sequence from bottom to top; the liquid collecting plate 5 is connected to an alkaline water outlet 51, the water washing spray layer 7 is connected to an alkaline water inlet 71, and the demister flushing spray layer 8 is connected to a desalted water inlet 81; the alkaline flushing water passes through the water washing spray layer and the cyclone ejector, is collected on the liquid collecting plate and flows back to the water washing tank to wash away the smoke in the sulfuric acid tail gas, and further absorbs SO2 in the sulfuric acid tail gas; the demister can remove the water mist in the sulfuric acid tail gas washed with alkaline water, and the desalted water passes through the demister flushing spray layer to clean the demister, and finally is collected on the liquid collecting plate and flows to the water washing tank; the top control flap is used to control the flow rate of the sulfuric acid tail gas to adapt to different production conditions.

[0032] The lower layer absorbs SO2 in the sulfuric acid tail gas through the circulation of organic amine liquid, and the upper layer reduces the smoke in the sulfuric acid tail gas through the circulation of alkaline water, and further absorbs SO2 in the sulfuric acid tail gas, thereby achieving ultra-low emissions of sulfuric acid tail gas.

[0033] A sulfuric acid tail gas inlet 11 is provided on the lower side wall of the absorption tower 1 below the lower filler 2; an organic amine liquid outlet 12 is provided at the bottom of the absorption tower 1; and a sulfuric acid tail gas outlet 13 is provided at the top of the absorption tower 1.

[0034] The lower packing 2 is a 316L perforated plate corrugated packing layer with a thickness of 5m and a specific surface area of ​​452m 2 / m 3 .

[0035] The liquid distribution plate 3 is a trough made of 316L, including a main trough and multiple sub-troughs below it; multiple liquid distribution holes are evenly distributed at intervals on the lower part of the two side walls of the main trough; the sub-trough is perpendicular to the main trough, and liquid distribution holes are evenly distributed at the bottom of the sub-trough; multiple sub-troughs are evenly distributed at intervals, and the liquid distribution holes of the main trough correspond to the sub-troughs one by one; the organic amine liquid enters the main trough through the organic amine liquid inlet, and the liquid distribution holes on the side of the main trough divide the amine liquid into the sub-troughs, and the liquid distribution holes at the bottom of the sub-troughs evenly distribute the amine liquid into the lower filler 2. Specifically, in this embodiment, 30 sub-troughs are provided, and 30 liquid distribution holes are evenly distributed on the lower part of the two side surfaces of the main trough, and the 30 sub-troughs are aligned with the 30 groups of liquid distribution holes respectively.

[0036] The upper packing 4 is a 316L perforated plate corrugated packing layer with a thickness of 0.5m and a specific surface area of ​​452m 2 / m 3 .

[0037] The liquid collecting plate 5 is a grooved plate made of glass fiber reinforced plastic with multiple grooves. The grooves are used to collect the upper alkaline flushing water, and the gaps between adjacent grooves are used for the circulation of sulfuric acid tail gas. An umbrella-shaped baffle is arranged above the gaps between adjacent grooves to prevent the alkaline flushing water from entering the lower amine solution.

[0038] The swirl ejector 6 is cylindrical and made of stainless steel, and the bottom is welded with steel plates to form swirl blades with a certain angle.

[0039] The water washing spray layer 7 is a water inlet main pipe connected to a plurality of thin pipes for diversion, and a glass fiber reinforced plastic nozzle is installed on the thin pipe to evenly distribute the alkaline desalted water into the swirl ejector 6.

[0040] A plastic hose is installed on the water inlet pipe of the demister flushing spray layer 8, and the other end of the plastic hose is connected to a PTFE nozzle. The PTFE nozzle is installed at the center of the cylindrical demister 9 to flush the demister 9; the demister 9 is cylindrical, and the bottom surface is made of PTFE plates to form blades with a certain angle, and a PTFE nozzle is installed in the center of the blades.

[0041] The control flap 10 controls five groups of flaps through five electric valves. Each group of flaps consists of an axis and multiple circular baffles. Each cylindrical demister 9 has a circular baffle on the top. The flow rate of the sulfuric acid tail gas is controlled by controlling the opening of each group of circular baffles.

[0042] As shown in the figure, the operation process of the absorption tower for tail gas desulfurization in this embodiment mainly includes:

[0043] The organic amine liquid enters the absorption tower through the organic amine liquid inlet, is evenly distributed through the liquid distribution plate, and is fully contacted with the sulfuric acid tail gas entering the absorption tower through the sulfuric acid tail gas inlet from the lower part of the absorption tower in the lower filler, absorbing SO2 in the sulfuric acid tail gas. The desulfurized sulfuric acid tail gas passes through the upper filler to intercept the escaping organic amine liquid.

[0044] Under the action of alkaline water washing in the water washing spray layer and centrifugal force when passing through the swirl ejector, the smoke and dust in the sulfuric acid tail gas finally enters the alkaline washing water, gathers on the liquid collecting plate and flows back to the water washing tank. On the one hand, it can wash away the smoke and dust in the sulfuric acid tail gas, and on the other hand, it can further absorb SO2 in the sulfuric acid tail gas.

[0045] After the sulfuric acid tail gas passes through the water washing spray layer, it passes through the demister to remove the water mist, further reducing the smoke and dust in the sulfuric acid tail gas, and finally is discharged through the sulfuric acid tail gas outlet.

[0046] During operation, desalted water is regularly used to flush the demister through the spray layer to ensure the demister's demisting effect. The flushing water eventually collects on the liquid collecting plate and flows to the washing tank.

[0047] A control flap is installed on the top of the demister. During operation, the flap opening is controlled according to different working conditions to control the flow rate of sulfuric acid tail gas and improve the dust removal effect.

[0048] Embodiment 2:

[0049] The present embodiment provides a process method for ultra-low and ultra-clean emissions of sulfur-containing tail gas, which realizes ultra-low and ultra-clean emissions of industrial sulfur-containing tail gas based on the absorption tower in Example 1; first, organic amine liquid is used to absorb SO2 in the tail gas, and then the tail gas is flushed with alkaline desalted water; the organic amine liquid absorbs SO2 in the tail gas, including: SO2 in the tail gas is absorbed by the organic amine liquid in the absorption tower; SO2 absorbed by the organic amine liquid is desorbed and released in the desorption tower; and the organic amine liquid is used for impurity removal and purification.

[0050] like Figure 2 As shown, the process method specifically includes the following steps:

[0051] Step 1, amine liquid absorption: the sulfur-containing tail gas is sprayed with an organic amine liquid to absorb the SO2 gas therein;

[0052] Step 2, washing with alkaline desalted water: the tail gas after amine desulfurization is washed with alkaline desalted water and then discharged into the atmosphere. The alkaline desalted water removes the smoke in the tail gas and further reduces the SO2 content in the tail gas. Specifically, the process of washing the tail gas with alkaline desalted water includes:

[0053] Step 2.1, spraying and flushing the tail gas with alkaline desalted water;

[0054] Step 2.2, regularly cleaning the demister with alkaline desalted water;

[0055] Step 2.3, controlling the pH value of the alkaline desalted water by NaOH;

[0056] Step 2.4, controlling the dust removal effect of the alkaline desalted water by blowdown.

[0057] Step 3, amine solution desorption: the organic amine solution that has absorbed SO2 releases high-concentration SO2 through desorption and enters the next process (in this implementation method, the high-concentration SO2 gas is purified, dried, and converted into sulfuric acid), and the desorbed organic amine solution enters the next absorption;

[0058] Step 4, amine solution purification: organic amine solution purification includes dust filtration, control of thermal stability salts, removal of harmful cations, and removal of highly corrosive acids. Specifically, organic amine solution impurity removal and purification includes:

[0059] Step 4.1, filtering solid impurities in the organic amine solution through a filter;

[0060] Step 4.2, controlling the heat-stable salt in the organic amine solution by anion exchange resin;

[0061] Step 4.3, removing harmful cations in the organic amine solution by cation exchange resin;

[0062] Step 4.4, removal of highly corrosive acids by Al2O3.

[0063] In the organic amine desulfurization process, the flow rate, temperature of the amine liquid and the flow rate and temperature of the sulfur-containing tail gas and other process parameters are controlled to ensure that the amine liquid is in full contact with the tail gas to improve the desulfurization efficiency; the desalted water washing process needs to control the flow rate and temperature of the desalted water, and use NaOH to control the pH of the desalted water within a certain range (normal pH 7-8) according to different working conditions. The demister is flushed regularly and the sewage is replaced to ensure the washing effect.

[0064] Before the organic amine liquid absorbs SO2, it is called lean amine liquid. After absorbing SO2 in the sulfur-containing tail gas through the absorption process, it is called rich amine liquid. The rich amine liquid releases high-concentration SO2 through the desorption process and becomes lean amine liquid again. The organic amine liquid completes the desulfurization process of the sulfur-containing tail gas through the continuous cycle of absorption and desorption. The desorption process controls the desorption flow and temperature.

[0065] This process method can absorb SO2 in the tail gas as much as possible to achieve ultra-low emissions after treating the sulfur-containing tail gas twice. Ultra-clean emissions are achieved after the smoke dust is washed. The dust removal effect of the desalted water washing process and the effect of secondary absorption of SO2 are controlled by controlling the discharge volume and pH value. The flow rate of sulfur-containing tail gas can be controlled according to different working conditions. The amine liquid purification process can ensure the long-term stable operation of the process system.

[0066] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the present invention.

[0067] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0068] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. An absorption tower for tail gas desulfurization, characterized in that: The absorption tower (1) comprises an absorption tower (1) and the absorption tower (1) is divided into two layers, an upper layer and a lower layer; The lower layer includes a lower filler (2) and a liquid distribution plate (3) above the lower filler, and the liquid distribution plate (3) is connected to an organic amine liquid inlet (31); The upper layer comprises an upper filler (4), a liquid collecting plate (5), a swirl ejector (6), a water washing spray layer (7), a demister flushing spray layer (8), a demister (9) and a control flap (10) which are located above the liquid distributing plate (3) and arranged in sequence from bottom to top; the liquid collecting plate (5) is connected to an alkaline water outlet (51), the water washing spray layer (7) is connected to an alkaline water inlet (71), and the demister flushing spray layer (8) is connected to a desalted water inlet (81); A sulfuric acid tail gas inlet (11) is provided on the lower side wall of the absorption tower (1) below the lower filler (2); an organic amine liquid outlet (12) is provided at the bottom of the absorption tower (1); and a sulfuric acid tail gas outlet (13) is provided at the top of the absorption tower (1).

2. The absorption tower for tail gas desulfurization according to claim 1, characterized in that: The lower filler (2) is a perforated plate corrugated filler layer with a thickness of 5m and a specific surface area of ​​452m 2 / m 3 .

3. The absorption tower for tail gas desulfurization according to claim 1, characterized in that: The liquid distribution plate (3) comprises a main tank and a plurality of sub-tanks below the main tank; a plurality of liquid distribution holes are arranged at equal intervals on the lower part of the two side walls of the main tank; the sub-tanks are perpendicular to the main tank, and the liquid distribution holes are evenly distributed at the bottom of the sub-tanks; the plurality of sub-tanks are evenly distributed at equal intervals, and the liquid distribution holes of the main tank correspond one to one with the sub-tanks; the organic amine liquid enters the main tank through the organic amine liquid inlet, the liquid distribution holes on the side of the main tank divert the amine liquid to the sub-tanks, and the liquid distribution holes at the bottom of the sub-tanks evenly distribute the amine liquid to the lower filler (2).

4. The absorption tower for tail gas desulfurization according to claim 1, characterized in that: The upper filler (4) is a perforated plate corrugated filler layer with a thickness of 0.5 m and a specific surface area of ​​452 m 2 / m 3 .

5. The absorption tower for tail gas desulfurization according to claim 1, characterized in that: The liquid collecting plate (5) is a grooved plate with a plurality of grooves, which is used to collect the upper alkaline flushing water. The gaps between adjacent grooves are used for the circulation of sulfuric acid tail gas. An umbrella-shaped baffle is arranged above the gaps between adjacent grooves to prevent the alkaline flushing water from entering the lower amine liquid.

6. The absorption tower for tail gas desulfurization according to claim 1, characterized in that: The swirl injector (6) is cylindrical, and the bottom thereof is welded with swirl blades using steel plates.

7. The absorption tower for tail gas desulfurization according to claim 1, characterized in that: The water washing spray layer (7) is a water inlet main pipe connected to a plurality of thin pipes for diversion, and a glass fiber reinforced plastic nozzle is installed on the thin pipe to evenly distribute the alkaline desalted water into the swirl ejector (6).

8. The absorption tower for tail gas desulfurization according to claim 1, characterized in that: A plastic hose is installed on the water inlet pipe of the demister flushing spray layer (8), and the other end of the plastic hose is connected to a polytetrafluoroethylene nozzle. The polytetrafluoroethylene nozzle is installed at the center of the cylindrical demister (9) to flush the demister (9).

9. The absorption tower for tail gas desulfurization according to claim 1, characterized in that: The control flap (10) controls five groups of flaps through five electric valves, each group of flaps is composed of a shaft and a plurality of circular baffles, and each cylindrical demister (9) has a circular baffle on the top, and the flow rate of the sulfuric acid tail gas is controlled by controlling the opening of each group of circular baffles.

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