CN104624020B - A kind of de-except the method for hydrogen sulfide in gas and solid dust - Google Patents

Abstract

The invention relates to a method for removing hydrogen sulfide and solid dust in gas. The purpose of the invention is to provide an effective process for removing hydrogen sulfide and solid particles contained in exhaust gas, so as to realize clean emission of exhaust gas. It specifically includes a wet absorption step and a dry dust removal step. The wet absorption step uses an absorption tower to absorb the acidic hydrogen sulfide in the exhaust gas, and the dry dust removal step uses a dust collector to remove solid dust particles.

Description

A method for removing hydrogen sulfide and solid dust in gas

technical field

The invention relates to a method for purifying gas, in particular to a method for purifying gas containing hydrogen sulfide and solid dust particles.

Background technique

In industry, for example, the shift gas produced by the shift section in fertilizer production or coking production or the tail gas of the coking industry usually contains H ₂ S and solid dust. Not only will it corrode the pipeline in the middle of the production process, but it will also affect the purity of the product, and what is more harmful is that it will pollute the environment after being discharged. H ₂ S is a colorless gas with a foul smell similar to rotten eggs. It is highly toxic and easily soluble in water. The aqueous solution is acidic and can form salt with alkali, so it can be absorbed by lye. H ₂ S is extremely toxic. When the concentration in the air reaches 140mg/m ³ , it will cause conjunctivitis and keratitis. When the concentration is about 280mg/m ³ , it will cause coma, respiratory paralysis and even death. Symptoms caused by low concentration of H ₂ S include headache, vomiting, insomnia, fatigue, eye and mucous membrane inflammation, so H ₂ S exhaust gas is a gas that has a greater impact on humans, animals and plants, and the country has also formulated strict emission regulations standard. It is stipulated that the maximum allowable concentration in the air is 0.06mg/m ³ . However, the disadvantage of conventional lye absorption is that the absorption is not complete, the absorption efficiency is low, and it is difficult to effectively remove solid particles in the exhaust gas. Therefore, it is necessary to develop an effective purification process to efficiently remove hydrogen sulfide and solid dust particles in the gas.

Contents of the invention

The purpose of the present invention is to provide an effective process for removing hydrogen sulfide and solid particles contained in the exhaust gas, so as to realize the clean discharge of the exhaust gas.

The technical solution adopted by the present invention to solve the technical problem is: a method for purifying exhaust gas containing hydrogen sulfide and solid dust, including a wet absorption step and a dry dust removal step, characterized in that the exhaust gas first enters the absorption tower 1 , after the gas inlet 2 of the absorption tower enters the absorption tower 1, it becomes a plurality of branch inlets 6, and the branch inlets 6 are evenly distributed in the absorption tower along the oblique line from top to bottom, the uppermost branch inlet is closest to the gas inlet 2, and the lowermost branch inlet The branch inlet is farthest from the gas inlet 2; a corresponding sprayer 5 is arranged on the upper part of each branch inlet, and the distance between each sprayer 5 and the corresponding branch inlet is 0.5-2m; the diethanolamine absorption liquid sprayed by the sprayer is the same as that in the exhaust gas. The hydrogen sulfide falls into the bottom of the absorption tower after fully reacting, and the absorption liquid at the bottom is circulated back to the sprayer under the action of the circulation pump 7 to continue to participate in the reaction;

The exhaust gas discharged from the absorption tower 1 then enters the dust collector 10. The exhaust gas first enters the dust collector from the inlet 11 of the dust collector. Section 16 enters the flow chamber 33 in the expansion section 17 of the dust collector, and the exhaust gas passes through the flow chamber 33 and contacts the filter element 30 in the filter element support frame 29, and the gas passes through the filter element 30 and is filtered and enters the exhaust chamber 32 to be discharged from the dust collector;

A small part of the exhaust gas hits the shunt cover 12 and flows down along the shunt cover 12, and hits 3-10 blades 28 fixed on the upper top plate 39 of the filter element support frame 29. The inner wall of the filter element support frame 29 is provided with a spiral slideway 36 , the spiral slideway 36 cooperates with the second spiral slideway on the outer wall of the annular inner baffle plate 15, the exhaust gas hits the blade 28, and the blade 28 drives the filter element support frame 29 to move downward while rotating along the second spiral slideway, and the support frame 29 The base plate 40 at the bottom is connected with a buffer component 27, and the other end of the buffer component 27 is fixed on the support block 20 on the inner wall 19 of the ash collection chamber; the support frame 29 rotates and moves downward together with the filter element 30, and the lower end of the filter element 30 enters the ash collection chamber 34 Inside, a scraper 22 is arranged on the outer wall 18 of the ring-shaped ash-collecting chamber near the entrance of the ash-collecting chamber 34, a brush 23 is provided below the scraper 22, and a nozzle 24 is provided at a corresponding position in the inner wall 19 of the ash-collecting chamber opposite to the brush 23 for Blow back blowing gas to the back of the filter element 30 ; under the joint action of the scraper 22 , the brush 23 and the nozzle 24 , remove the particles adsorbed and filtered by the filter element 30 , and the filter element 30 is regenerated.

Preferably, the number of branch entrances is 4-8.

Preferably, the distance between the sprayer and the branch inlet is 1-1.5m.

Preferably, the filter element of the dust remover is an activated carbon filter element, polypropylene fiber, metal fiber, glass fiber.

Preferably, the number of blades is 7 pieces.

Preferably, the buffer component is a damping rod, a hydraulic rod or a spring, and the number thereof may be 2-8.

Preferably, the shunt cover is provided with a discharge port.

The beneficial effects of the present invention are:

1. The method of absorbing tabu gas is unique, which greatly improves the gas distribution effect and gas-liquid contact efficiency, and greatly improves the purification effect.

2. During the work of the dust collector, the filter element can rotate continuously for regeneration and recycling, and the regeneration operation does not require additional operating power, and the movement of the filter element can be realized only by the kinetic energy of the exhaust itself, saving energy and low consumption.

3. By combining wet deacidification and dry dust removal methods, hydrogen sulfide and solid particles in the exhaust can be efficiently removed, which is energy-saving and environmentally friendly.

Description of drawings

Fig. 1 is a process roadmap of the present invention.

Fig. 2 is a schematic diagram of the wet absorption tower of the present invention.

Fig. 3 is a front view of the dust remover of the present invention.

Fig. 4 is an AA sectional view of the dust remover of the present invention.

Fig. 5 is a schematic diagram of the shunt hood of the dust remover of the present invention.

Fig. 6 is a perspective view of the support frame of the dust remover of the present invention.

The descriptions of the reference signs and their corresponding parts are as follows:

1. Absorption tower; 2. Absorption tower gas inlet; 3. Absorption tower gas outlet; 4. Demister; 5. Sprayer; 6. Branch inlet; 7. Circulation pump; 10. Dust collector; 11. Dust collector inlet; 12. Shunt cover; 13. Discharge port; 14. Annular outer baffle; 15. Annular inner baffle; 16. Gradually expanding section; 17. Expansion section; 19. Lower baffle; 20. Support block; 21. Seal Ring; 22, scraper; 23, brush; 24, nozzle; 25, blowback valve; 26, ash discharge valve; 27, buffer component; 28, blade; 29, support frame; 30, filter element; 31 filter plate; , exhaust cavity; 33, flow cavity; 34, ash collection cavity; 35, discharge cavity; 36, spiral slideway; 38, fastening ring; 39, top plate; 40, bottom plate

detailed description

The following examples are used to illustrate the present invention, but not to limit the scope of the present invention.

The present invention is an exhaust purification method, which comprises a wet absorption step and a dry dust removal step. The dust content in the exhaust gas containing hydrogen sulfide is about 3-70mg/m ³ , and the hydrogen sulfide content is about 8000mg/Nm ³ . The exhaust gas enters the absorption tower first, and the acidic exhaust gas enters from the gas inlet of the absorption tower, and reacts with the atomized diethanolamine, the exhaust releases heat to cool down, and the absorption liquid evaporates rapidly; the acid gas in the exhaust gas fully contacts with the absorption liquid reaction, H ₂ S can be effectively removed. Part of the dust contained in the exhaust gas is also absorbed and removed by the atomized absorption liquid.

The exhaust gas treated by the absorption tower then enters the dust collector, and passes through the filter element of the dust collector to effectively remove the remaining solid particles in the exhaust gas. Since the acidic and corrosive substances in the exhaust gas have been removed in the absorption tower, the dust collector The filter elements in the filter have a wide range of choices, and non-acid-resistant and corrosion-resistant filter elements can be used. The purified exhaust can be discharged into the atmosphere through induced draft fans and other mechanisms.

Example:

As shown in Figure 1 and Figure 2, the 150-250 °C shift gas containing hydrogen sulfide and solid dust particles first enters the absorption tower 1, and the gas inlet 2 of the absorption tower enters the absorption tower 1 and becomes four branch inlets 6, and the branch inlets 6 are evenly distributed in the absorption tower along the oblique line from top to bottom, the uppermost branch inlet is the closest to the gas inlet 2, and the lowermost branch inlet is the farthest from the gas inlet 2. The 4 branch inlets can basically realize the uniform distribution of gas. A corresponding sprayer 5 is provided on the upper part of each branch entrance, and the sprayer 5 is 1m away from the branch entrance. Since the gas inlet is divided into several branch inlets, the reaction efficiency can be improved by setting corresponding sprayers at each branch inlet, and the distribution degree of the exhaust gas in the absorption tower can be improved. In addition to the sprayer 5 provided correspondingly, a conventional sprayer is also arranged on the top of the absorption tower to further improve the gas-liquid contact efficiency. After the diethanolamine fully reacts with the hydrogen sulfide in the exhaust, it falls into the bottom of the absorption tower, and the absorption liquid at the bottom is circulated back to the sprayer under the action of the circulation pump 7 to continue to participate in the reaction. Through this strong mass and heat transfer process, the acidic pollutants in the exhaust gas are fully combined with diethanolamine, and the acidic gases in the exhaust gas are fully removed. A mist eliminator 4 is installed on the top of the absorption tower, and the wet exhaust gas passes through the mist eliminator 4 and then exits the absorption tower from the gas outlet 3 of the absorption tower. In the exhaust after passing through the absorption tower, the concentration of H ₂ S can be reduced from the initial 8000 mg/Nm ³ to about 3 mg/Nm ³ .

The exhaust gas discharged from the absorption tower 1 then enters the dust collector 10. The exhaust gas first enters the dust collector from the dust collector inlet 11, and the exhaust gas first impacts on the shunt cover 12. The shunt cover is a conical body. Next, most of the exhaust gas enters the flow chamber 33 in the expansion section of the dust collector through the gradual expansion section. The wall of the expansion section of the dust collector and the inner annular outer baffle 14 constitute the flow chamber 33. After the exhaust gas passes through the flow chamber 33, the same The filter element 30 in the filter element support frame 29 contacts, and the filter element 30 is an activated carbon filter element. The annular outer baffle plate 14 together with the annular inner baffle plate 15, the outer wall 18 of the ash collection chamber and the inner wall 19 of the ash collection chamber together constitute the gas flow path on the filter element 30, and a sealing ring 21 is arranged between the filter element 30 and the outer wall 18 of the ash collection chamber. It is used to prevent gas from entering the ash collection chamber 34 without passing through the filter element 30 . Particles and toxic substances in the gas are adsorbed and filtered by the filter element 30, and the purified gas enters the exhaust chamber 32 and is discharged from the dust collector after being filtered by the filter element 30. The ring-shaped filter element 30 will deposit a layer of filtered particles on the surface of the filter element during filtering, and the deposited particles will reduce the filtering effect of the filter element, so the filter element needs to be periodically regenerated.

The regeneration process of the filter element 30: see Fig. 3, Fig. 4, Fig. 6. After the exhaust gas enters the dust collector from the dust collector inlet 11, as mentioned above, most of the exhaust gas enters the flow chamber 33 under the guidance of the shunt cover 12 and enters the filtration stage. In addition, after a small part of the exhaust gas hits the shunt cover 12 It flows downward along the shunt cover 12 and hits the blade 28 fixed on the upper top plate 39 of the filter element support frame 29. The inner wall of the filter element support frame 29 is provided with a spiral slideway 36, and the spiral slideway 36 is connected with the spiral slide on the outer wall of the annular inner baffle. Road (not shown), therefore, the exhaust hits the vane 28, and the vane 28 drives the filter element support frame 29 to move downward while rotating under the support and guidance of the spiral slideway. The support frame 29 rotates and moves downward together with the filter element 30 and enters the ash collection chamber 34. The support frame 29 is in close contact with the inner wall 19 of the ash collection chamber. There is a certain space between the filter element 30 and the outer wall 18 of the ash collection chamber. Close to the entrance of the ash collection chamber, there are two scrapers 22 correspondingly arranged first. The scrapers 22 are close to the filter element 30. A brush 23 is arranged under the scraper 22. The bristles of the brush 23 contact the filter element 30. The inner wall 19 of the ash collection chamber opposite to the brush 23 is A nozzle 24 is provided at a corresponding position for blowing back blowing gas to the back of the filter element 30 , and a back blowing valve 25 controls the flow rate of the back blowing gas. Under the action of the scraper 22, the impurities deposited on the surface of the rotating filter element 30 are scraped off by the scraper, and the filter element 30 further rotates and descends, and then the particulate matter adsorbed and filtered by the filter element 30 is further removed under the combined action of the brush 23 and the nozzle 24. It can be regenerated under the treatment of multiple regeneration methods. The removed impurities fall into the bottom of the ash collecting chamber 34, and after accumulating to a certain extent, they are discharged out of the dust collector through the ash unloading valve 26. The amount of ash accumulated in the ash collection chamber 34 can be detected by automatic detection means such as particle sensor detection.

Referring to Fig. 3, the bottom circumference of the shunt cover 12 is fixedly connected with the annular inner baffle 15, the support frame 29 rotates and descends around the annular inner baffle 15, and the bottom plate 40 at the bottom of the support frame 29 is connected with a buffer member 27, the buffer member is preferably The damping rod, the other end of the buffer component 27 is fixed on the support block 20 on the inner wall of the ash collection chamber. The effect of buffer member 27 is to control the descending speed of support frame 29, prevents descending too fast. The position and quantity of the buffering member 27 can be selected according to needs, and it is advisable not to block the nozzle 24 of course. In FIG. Of course, other devices with similar functions can also be used, such as hydraulic rods, springs and the like. In addition, the descending speed of the support frame 29 can also be adjusted by setting blades 28 of different numbers and angles. In this embodiment, the number of blades is preferably 7. According to the flow rate of the exhaust, 7 blades can achieve a better rotation speed. , it is also possible to reduce or increase the descending speed of the support frame 29 by setting fewer or more blades, for example, it may be 3, 5, 10 and so on. During the regeneration process, after most of the filter element 30 has fallen into the ash collection chamber 34 and is regenerated, the buffer component or other similar components can be controlled to apply pressure to the support frame 29 in reverse, such as stopping the air intake, and the compressed buffer component will Prompt the support frame 29 to reversely rotate and rise back to the initial working state, and thus work in a cyclical manner.

Referring to FIG. 5 , this figure is a perspective view of the shunt cover 12 . A discharge port 13 may be provided on the flow cover 12 . Normally, the discharge port 13 is closed and gas cannot pass through the flow cover 12 . When the pressure sensor (not shown) in the dust collector measures that the pressure in the dust collector is higher than the normal value, the discharge port 13 is opened, and the air flow can flow through the discharge port 13, enter the discharge cavity 35, and pass through the filter plate 31 After filtration, it is discharged from the dust collector. The opening and closing of the discharge port 13 can be remotely controlled by a closing switch at the discharge port. When the dust collector is running, sometimes it encounters the input air flow with large fluctuations in flow rate and flow velocity, and sometimes encounters accidental clogging of the filter. When encountering a similar situation that increases the pressure inside the dust collector, it can be opened to ensure production safety. The discharge port 13 is used to quickly reduce the pressure in the dust collector to prevent damage to the filter element or the dust collector. Due to the existence of the filter plate 31, the safety of the discharged gas can also be ensured.

Referring to Fig. 6, this figure is a perspective view of the support frame 29, the blade 28 is fixed on the top plate 39 at the upper end of the support frame 29, the main body of the support frame 29 is composed of a vertical grid and a plurality of fastening rings 38 for reinforcement The substantially net-like air-permeable structure, the inner wall of the support frame 29 is fixed with a spiral slideway 36 to guide the support frame 29 to rotate and descend around the annular inner baffle. The material of the support frame 29 and the spiral slideway 36 can be any material with certain rigidity, such as stainless steel, plastic and the like.

After the exhaust gas passes through the absorption tower 1 and the dust collector 10, the acidic substances and solid particles in the gas are basically removed, and the gas reaches the emission standard.

In the purification method of the present invention, the absorption tower used greatly improves the gas distribution effect and gas-liquid contact efficiency through a unique gas distribution means, and greatly improves the purification effect. The filter element used by the dust collector can be continuously regenerated and recycled during operation, and no additional operating power is required, and the regeneration of the filter element can be realized only by the kinetic energy of the exhaust gas itself. Due to the combined use of the absorption tower and the dust remover of the present invention, the hydrogen sulfide and solid particles in the exhaust gas are effectively removed, and the clean emission of the exhaust gas is realized.

The embodiment described above is only a preferred solution of the present invention, and does not limit the present invention in any form. There are other variations and modifications on the premise of not exceeding the technical solution described in the claims.

Claims (7)

1. A method for purifying exhaust gas containing hydrogen sulfide and solid dust, comprising a wet absorption step and a dry dust removal step, characterized in that: the exhaust gas first enters the absorption tower (1), and the absorption tower gas inlet (2) enters After the absorption tower (1) becomes a plurality of branch inlets (6), the branch inlets (6) are evenly distributed in the absorption tower along the oblique line from top to bottom, the uppermost branch inlet is closest to the gas inlet (2), and the bottom The branch inlet of each branch is farthest from the gas inlet (2); a corresponding sprayer (5) is arranged on the top of each branch entrance, and the distance of each sprayer (5) from the corresponding branch entrance is 0.5-2m; The ethanolamine absorption liquid fully reacts with the hydrogen sulfide in the exhaust gas and falls into the bottom of the absorption tower, and the absorption liquid at the bottom is circulated back to the sprayer under the action of the circulation pump (7) to continue to participate in the reaction; The exhaust gas discharged from the absorption tower (1) then enters the dust collector (10), and the exhaust gas first enters the dust collector from the inlet (11) of the dust collector, and the front of the exhaust gas impacts on the shunt cover (12), and the shunt cover is a conical body , most of the exhaust gas enters the flow cavity (33) in the expansion section (17) of the dust collector through the gradual expansion section (16), and the exhaust gas passes through the flow cavity (33) and is connected with the filter element (30) in the filter element support frame (29) Contact, the gas passes through the filter element (30) and then enters the exhaust chamber (32) to be discharged from the dust collector; a small part of the exhaust gas hits the shunt cover (12) and then flows down along the shunt cover (12), hitting the filter element support frame (29) 3-10 blades (28) are fixed on the upper top plate (39), and the inner wall of the filter element support frame (29) is provided with a spiral slideway (36), and the spiral slideway (36) and the annular inner baffle plate (15 ) on the outer wall of the second spiral slideway, the exhaust air hits the blade (28), and the blade (28) drives the filter element support frame (29) to move downward while rotating along the second spiral slideway, and the bottom of the filter element support frame (29) The bottom plate (40) of the bottom plate (40) is connected with a buffer component (27), and the other end of the buffer component (27) is fixed on the support block (20) on the ash collection cavity inner wall (19); the filter element support frame (29) is connected with the filter element (30) ) rotates and moves downward, the lower end of the filter element (30) enters the ash collection chamber (34), and the outer wall (18) of the annular ash collection chamber (18) is correspondingly provided with a scraper (22) near the entrance of the ash collection chamber (34), and the scraper (22) The bottom is provided with a hairbrush (23), and a nozzle (24) is provided at a corresponding position in the ash collecting cavity inner wall (19) opposite to the hairbrush (23) to blow back blowing gas to the back of the filter element (30); ), the brush (23) and the nozzle (24) remove the particulate matter adsorbed and filtered by the filter core (30), and the filter core (30) is regenerated. 2. The purification method according to claim 1, characterized in that: the number of branch inlets (6) is 4-8. 3. The purification method according to claim 1, characterized in that the distance between the sprayer (5) and the branch inlet (6) is 1-1.5m. 4. The purification method according to claim 1, characterized in that: the filter element (30) of the dust remover is activated carbon, polypropylene fiber, metal fiber, glass fiber. 5. The purification method according to claim 1, characterized in that: the number of blades (28) is seven. 6. The purification method according to claim 1, characterized in that: the buffer member (27) is a damping rod, a hydraulic rod or a spring, the number of which is 2-8. 7. The purification method according to claim 1, characterized in that: the shunt cover (12) is provided with a discharge port (13).