Desulfurization, denitration and dust removal system for high-temperature flue gas

Abstract

The utility model discloses a high-temperature flue gas desulfurization, denitrification and dust removal system which comprises a dry desulfurization tower, a cyclone dust collector, dust and nitrate integrated equipment, a desulfurization agent storage and feeding system, a material returning system, an ash conveying system, a waste ash storage system, a fluidization air system and an ammonia water storage and injection system, an ash hopper is arranged at the bottom of the shell; metal filter cartridges are uniformly distributed at the lower part of the tubesheet; a gas purification chamber is arranged at the upper part of the tubesheet and is communicated with the interiors of the metal filter cartridges; a catalyst layer is arranged in the gas purification chamber, a denitration catalyst is filled in the catalyst layer, and a purified gas outlet is formed in the top of the gas purification chamber. According to the dust and nitrate integrated equipment disclosed by the utility model, the high-temperature-resistant metal filter cartridge is used for removing dust in flue gas, a denitration catalyst is arranged in a low-dust environment, the abrasion of high-concentration dust to the catalyst is avoided, and the feeding and returning system of the dry desulfurization tower realizes uniform feeding and ensures the desulfurization efficiency.

Description

Technical Field

[0001] The utility model relates to the technical field of high-temperature flue gas desulfurization, denitrification and dust removal treatment, in particular to a high-temperature flue gas desulfurization, denitrification and dust removal system. Background Technique

[0002] Dry desulfurization is widely used in flue gas desulfurization due to its wide application range and the characteristic of not increasing the flue gas humidity under the condition of ensuring the desulfurization efficiency. However, due to the low utilization rate of the desulfurizer and the slow reaction rate, it is necessary to increase the amount of returned ash to ensure the desulfurization efficiency, so continuous and stable return of materials is very important. Filter dust removal has always been an efficient dust removal method. However, due to high-temperature limitations, conventional fiber filter bags cannot meet the requirements of high-temperature working conditions. Metal filter cartridges can meet the requirements of high-temperature flue gas dust removal due to their inherent stability and high-temperature resistance characteristics. SCR has always been an efficient denitrification method. When used in a high-dust environment, a dust cleaning system needs to be equipped. If the dust cleaning is not appropriate, it will cause catalyst wear or even penetration, affect the service life of the catalyst, and ultimately reduce the denitrification efficiency. Content of the Utility Model

[0003] To solve the above technical problems, the utility model designs a high-temperature flue gas desulfurization, denitrification and dust removal system integrating dry desulfurization, metal filter cartridge dust removal and SCR denitrification. The continuous and stable ash return method stabilizes the dry desulfurization efficiency. The metal filter cartridge dust removal and SCR integrated structure is adopted to ensure the dust removal and denitrification efficiency. At the same time, the catalyst is in a low-dust environment, which improves the service life of the catalyst.

[0004] The utility model adopts the following technical scheme:

[0005] A high-temperature flue gas desulfurization, denitrification and dust removal system includes a dry desulfurization tower, a cyclone dust collector, a dust and nitrate integration device, a desulfurizer storage and feeding system, a return material system, an ash conveying system, a waste ash storage system, a fluidizing air system and an ammonia water storage and injection system. The flue gas outlet of the dry desulfurization tower is connected to the cyclone dust collector, the flue gas after dust removal by the cyclone dust collector is connected to the dust and nitrate integration device, the materials collected by the cyclone dust collector are transported to the return material system, the ammonia water storage and injection system is connected in the flue before the dry desulfurization tower, the throat of the dry desulfurization tower is connected to the return material system and the desulfurizer storage and feeding system, the dry desulfurization tower, the dust and nitrate integration device and the return material system are respectively connected to the ash conveying system, and the ash conveying system is connected to the waste ash storage system. The dust and nitrate integration device includes a shell, the shell is separated up and down by a perforated plate, a hopper is arranged at the bottom of the shell, metal filter cartridges are uniformly distributed below the perforated plate, the upper part of the perforated plate is a clean gas chamber, the clean gas chamber is connected to the inside of the metal filter cartridges, a catalyst layer is arranged in the clean gas chamber, denitrification catalyst is installed in the catalyst layer, and a purified gas outlet is arranged at the top of the clean gas chamber.

[0006] Preferably, a blowpipe is provided corresponding to the metal filter cartridge in the clean gas chamber, spray nozzles are provided on the blowpipe corresponding to each metal filter cartridge, and a pulse valve and a metal expansion joint are connected to the blowpipe.

[0007] Preferably, an inlet for flue gas is provided at the lower part of the housing, an inlet electric valve is provided on the inlet for flue gas, an outlet electric valve is provided at the purification gas outlet, and an air flow distribution device is provided corresponding to the inlet for flue gas at the lower part of the housing.

[0008] Preferably, the desulfurizer storage and feeding system includes a desulfurizer bin, an electric feeder, a weighing chute, a variable-frequency feeder, and a gasification chute. The desulfurizer bin, the electric feeder, the weighing chute, the variable-frequency feeder, and the gasification chute are sequentially connected by pipelines, and the gasification chute is communicated with the dry desulfurization tower.

[0009] Preferably, a bypass pipeline is communicated between the weighing chute and the gasification chute, and a pneumatic valve is installed on the bypass pipeline.

[0010] Preferably, the return material system includes a return material hopper, a double-screw feeder, and a gasification chute. The return material hopper is connected to the double-screw feeder below, the double-screw feeder is connected to the gasification chute below, and the gasification chute is communicated with the dry desulfurization tower.

[0011] Preferably, the desulfurizer storage and feeding system is communicated with a fluidizing air system. The fluidizing air system includes a fluidizing air blower and an electric heater, and the fluidizing air blower and the electric heater are communicated with the desulfurizer bin, the weighing chute, and the gasification chute through pipelines.

[0012] Preferably, the ash conveying system includes a conveying pipeline and a gas storage tank. A switching valve is provided on the conveying pipeline, which can be directed to convey the materials collected from the dry desulfurization tower and the dust and nitrate integration equipment to the return material system or the waste ash storage system.

[0013] The beneficial effects of the present utility model are as follows: The present utility model provides a high-temperature flue gas desulfurization, denitrification and dust removal system, which is applicable to the purification of high-temperature flue gas. The high-temperature resistant metal filter cartridge in the dust and nitrate integration equipment is used to remove dust in the flue gas. The denitrification catalyst is installed in a low-dust environment, avoiding the abrasion of the catalyst by high-concentration dust. The dry desulfurization tower feeding and return material system realizes uniform feeding and ensures the desulfurization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic structural diagram of the present utility model;

[0015] Figure 2 is a schematic structural diagram of the dust and nitrate integration equipment in the present utility model;

[0016] Figure 3 is a schematic structural diagram of the desulfurizer storage and feeding system in the present utility model;

[0017] In the figure: 1 - dry desulfurization tower; 2 - cyclone dust collector; 3 - integrated dust and NOx removal equipment; 4 - desulfurizer storage and feeding system; 5 - return material system; 6 - ash conveying system; 7 - waste ash storage system; 8 - fluidizing air system; 9 - ammonia water storage and injection system;

[0018] 31 - inlet electric valve; 32 - air flow distribution device; 33 - metal filter cartridge; 34 - perforated plate; 35 - injection pipe; 36 - metal expansion joint; 37 - pulse valve; 38 - denitration catalyst; 39 - outlet electric valve;

[0019] 41 - desulfurizer bin; 42 - electric feeder, 43 - weighing chute; 44 - variable frequency feeder; 45 - pneumatic valve; 46 - pneumatic conveying chute. Specific embodiments

[0020] The technical solution of the present utility model will be further specifically described below through specific embodiments in conjunction with the accompanying drawings:

[0021] Embodiment: As Figures 1 - 3 shown, a high-temperature flue gas desulfurization, denitration and dust removal system includes a dry desulfurization tower 1, a cyclone dust collector 2, an integrated dust and NOx removal equipment 3, a desulfurizer storage and feeding system 4, a return material system 5, an ash conveying system 6, a waste ash storage system 7, an ammonia water storage, fluidizing air system 8 and an injection system 9. The flue gas outlet of the dry desulfurization tower is connected to the cyclone dust collector, the flue gas after dust removal by the cyclone dust collector is connected to the integrated dust and NOx removal equipment, the material collected by the cyclone dust collector is transported to the return material system, the ammonia water storage and injection system is connected in the flue before the dry desulfurization tower, the throat of the dry desulfurization tower is connected to the return material system and the desulfurizer storage and feeding system, the dry desulfurization tower, the integrated dust and NOx removal equipment and the return material system are respectively connected to the ash conveying system, the ash conveying system is connected to the waste ash storage system. The integrated dust and NOx removal equipment includes a shell, the shell is divided up and down by a perforated plate 34, a hopper is arranged at the bottom of the shell, metal filter cartridges 33 are evenly distributed below the perforated plate, the upper part of the perforated plate is a clean gas chamber, the clean gas chamber is connected to the inside of the metal filter cartridge, a catalyst layer is arranged in the clean gas chamber, a denitration catalyst 38 is installed in the catalyst layer, and a purified gas outlet is arranged at the top of the clean gas chamber.

[0022] An injection pipe 35 is arranged in the clean gas chamber corresponding to the metal filter cartridge, nozzles are arranged on the injection pipe corresponding to each metal filter cartridge, and a pulse valve 37 and a metal expansion joint 36 are connected to the injection pipe.

[0023] An inlet for flue gas is arranged at the lower part of the shell, an inlet electric valve 31 is arranged on the inlet for flue gas, an outlet electric valve 39 is arranged at the purified gas outlet, and an air flow distribution device 32 is arranged at the lower part of the shell corresponding to the inlet for flue gas.

[0024] The desulfurizer storage and feeding system includes a desulfurizer bin 41, an electric feeder 42, a weighing chute 43, a variable-frequency feeder 44, and a pneumatic chute 46. The desulfurizer bin, the electric feeder, the weighing chute, the variable-frequency feeder, and the pneumatic chute are connected in sequence through pipelines, and the pneumatic chute is connected to the dry desulfurization tower.

[0025] A bypass pipeline is connected between the weighing chute and the pneumatic chute, and a pneumatic valve 45 is installed on the bypass pipeline. The return material system includes a return hopper, a double-screw feeder, and a pneumatic chute. The return hopper is connected to the double-screw feeder below, the double-screw feeder is connected to the pneumatic chute below, and the pneumatic chute is connected to the dry desulfurization tower.

[0026] The desulfurizer storage and feeding system is connected to a fluidizing air system 8. The fluidizing air system includes a fluidizing air blower and an electric heater. The fluidizing air blower and the electric heater are connected to the desulfurizer bin, the weighing chute, and the pneumatic chute through pipelines.

[0027] The ash conveying system includes a conveying pipeline and a gas storage tank. A switching valve is provided on the conveying pipeline, which can be directed to convey the materials collected from the dry desulfurization tower and the dust and nitrate integration equipment to the return material system or the waste ash storage system.

[0028] When the utility model is in use, atomized ammonia water is sprayed into the flue before the high-temperature flue gas enters the dry desulfurization tower 1 through the ammonia water storage and spraying system 9. Under high-temperature conditions, the ammonia water evaporates to form ammonia gas, which is fully mixed with the high-temperature flue gas. After entering the dry desulfurization tower 1, desulfurizer and return material are added at the throat of the dry desulfurization tower. Sulfur dioxide in the flue gas reacts with the desulfurizer to remove sulfur dioxide in the flue gas. Subsequently, the flue gas enters the cyclone dust collector 2 for pre-dust removal, and then the flue gas enters the dust and nitrate integration equipment 3. The dust and nitrate integration equipment 3 is equipped with metal filter cartridges. The flue gas passes through the outer surface of the metal filter cartridges, and the dust is blocked on the outer surface of the metal filter cartridges. The clean gas rises from the inside of the metal filter cartridges to the clean gas chamber. The clean gas chamber is equipped with a catalyst. Under the action of the catalyst, nitrogen oxides in the flue gas fully react with ammonia gas, and finally the purpose of removing nitrogen oxides is achieved. The treated clean gas is discharged from the outlet of the dust and nitrate integration equipment.

[0029] The integrated dust and nitrate removal equipment 3 adopts a modular method and consists of a certain number of chambers according to the equipment selection. Taking the single-chamber structure as an example. The high-temperature flue gas enters the chamber through the chamber inlet pipe. Part of the dust falls into the ash hopper under the action of gravity. The remaining dust, along with the gas flow, is evenly upward and passes through the metal filter cartridge 33 under the action of the gas flow distribution device 32. The dust is intercepted on the outer surface of the metal filter cartridge 33. The high-temperature flue gas passes through the metal filter cartridge and then passes through the perforated plate 34 and enters the clean gas chamber. The denitration catalyst 38 is installed in the clean gas chamber. When the high-temperature flue gas passes through the catalyst layer, the nitrogen oxides in the high-temperature flue gas and ammonia are accelerated to react fully. The treated gas is discharged through the chamber outlet pipe. A blowpipe 35 is installed in the clean gas chamber. The blowpipe is provided with blowholes, and nozzles are arranged at the corresponding positions of the holes. One end of the blowpipe is connected to the air bag, and the other end is fixed with a head. A pulse valve 37 is installed on the air bag. The opening time of the pulse valve is in milliseconds. When it is opened, the high-pressure gas in the air bag enters the blowpipe, and through the blowholes and nozzles, it is sprayed into the interior of the metal filter cartridge 33 in the form of pulses. Under the action of the pulsed high-pressure gas, the dust intercepted on the outer surface of the metal filter cartridge is blown into the ash hopper. A metal expansion joint 36 is provided on the connecting pipe section between the blowpipe and the air bag outside the chamber to offset the thermal expansion caused by the high temperature of the blowpipe. An inlet electric valve 31 is installed on the chamber inlet pipe, and an outlet electric valve 39 is installed on the outlet pipe. By starting and stopping the electric valve, it can be selected whether this chamber participates in the operation. When it is necessary to repair the internal components of the chamber under the condition that the desulfurization, denitration and dust removal system is not shut down, the inlet electric valve 31 and the outlet electric valve 39 of the chamber are closed, and this chamber is cut off from operation, realizing the maintenance under the condition that the system is not shut down. At the same time, by adjusting the valve opening degrees of the inlet electric valve 31 and the outlet electric valve 39, the flue gas volume processed by the chamber can be adjusted, and the balance of the flue gas volumes processed by each chamber is ensured during the operation of multiple chambers.

[0030] The desulfurization agent stored in the desulfurization agent bin 41 enters the weighing chute 43 through the electric feeder 42. The weighing chute is equipped with a weighing meter for detecting the weight of the desulfurization agent in the weighing chute, so as to obtain the amount of desulfurization agent sprayed into the dry desulfurization tower. The weighing chute is equipped with two discharge pipes, which are respectively equipped with a variable-frequency feeder 44 and a pneumatic valve 45. The desulfurization agent enters the gasification chute 46 through the variable-frequency feeder 44 and the pneumatic valve 45, and is finally transported to the dry desulfurization tower 1. When the environmental protection system operates normally, only the variable-frequency feeder 44 is needed to meet the desulfurization requirements. The pneumatic valve 45 is used as an auxiliary device and is opened at the initial stage of system operation, when the variable-frequency feeder 44 fails or rapid feeding is required. The gasification chute 46 can stabilize the feeding amount of the dry desulfurization tower and avoid instantaneous overfeeding or underfeeding.

[0031] Due to reasons such as low flue gas flow velocity or the falling off of the return material plate in the dry desulfurization tower 1, some desulfurization agents or return materials will fall into the cone hopper. The return materials and desulfurization agents in the cone hopper, together with the dust collected in the ash hopper of the dust and nitrate integration equipment 3, are transported through the ash transportation system 6. A switching valve is provided on the transportation pipeline, which can direct the collected materials to be transported to the return material system 5 or the waste ash storage system 7.

[0032] The return material system 5 consists of a return material hopper, a double - screw feeder, and an air - fluidized chute. The materials collected by the cyclone dust collector 2, together with the materials transported by the ash transportation system, are stored in the return material hopper. The return material hopper is connected to the double - screw feeder and the air - fluidized chute below, which are used to transport the materials in the return material hopper into the dry desulfurization tower to ensure the desulfurization efficiency. The double - screw feeder has one in use and one in reserve to ensure the trouble - free operation of the return material system.

[0033] The fluidizing air system includes a fluidizing air blower and an electric heater. The fluidizing air leads to the desulfurization agent bin 41, the weighing chute 43, and the air - fluidized chute respectively, increasing the fluidity of the desulfurization agent and the return materials to ensure smooth feeding.

[0034] The above - described embodiments are only a preferred solution of the present utility model, and do not impose any form of limitation on the present utility model. There are other variations and modifications without exceeding the technical solutions recorded in the claims.

Claims

1. A high-temperature flue gas desulfurization, denitrification and dust removal system, comprising a dry desulfurization tower, a cyclone dust collector, a dust and nitrate integration device, a desulfurizing agent storage and feeding system, a return material system, an ash conveying system, a waste ash storage system, a fluidizing air system and an ammonia water storage and injection system. The flue gas outlet of the dry desulfurization tower is connected to the cyclone dust collector, the flue gas after dust removal by the cyclone dust collector is connected to the dust and nitrate integration device, the material collected by the cyclone dust collector is conveyed to the return material system, the ammonia water storage and injection system is connected to the flue duct in front of the dry desulfurization tower, the return material system and the desulfurizing agent storage and feeding system are connected to the throat of the dry desulfurization tower, the dry desulfurization tower, the dust and nitrate integration device and the return material system are respectively connected to the ash conveying system, and the ash conveying system is connected to the waste ash storage system. It is characterized in that The integrated dust and NOx removal equipment includes a housing, which is separated up and down by a perforated plate. A hopper is arranged at the bottom of the housing. Metal filter cartridges are evenly distributed below the perforated plate. The upper part of the perforated plate is a clean gas chamber, which is communicated with the inside of the metal filter cartridges. A catalyst layer is arranged in the clean gas chamber, and a denitration catalyst is installed in the catalyst layer. A purified gas outlet is arranged at the top of the clean gas chamber.

2. The high-temperature flue gas desulfurization, denitrification and dust removal system according to claim 1, characterized in that, A blowpipe is arranged in the clean gas chamber corresponding to the metal filter cartridges. Nozzles are arranged on the blowpipe corresponding to each metal filter cartridge. A pulse valve and a metal expansion joint are connected to the blowpipe.

3. A high-temperature flue gas desulfurization, denitrification and dust removal system according to claim 1, characterized in that, An inlet flue is arranged at the lower part of the housing, and an inlet electric valve is arranged on the inlet flue. An outlet electric valve is arranged at the purified gas outlet. An air flow distribution device is arranged at the lower part of the housing corresponding to the inlet flue.

4. A high-temperature flue gas desulfurization, denitrification and dust removal system according to claim 1, characterized in that, The desulfurizer storage and feeding system includes a desulfurizer bin, an electric feeder, a weighing chute, a variable-frequency feeder and a gasification chute. The desulfurizer bin, the electric feeder, the weighing chute, the variable-frequency feeder and the gasification chute are sequentially connected by pipelines, and the gasification chute is communicated with the dry desulfurization tower.

5. The high-temperature flue gas desulfurization, denitrification and dust removal system according to claim 4, characterized in that, A bypass pipeline is communicated between the weighing chute and the gasification chute, and a pneumatic valve is installed on the bypass pipeline.

6. The high-temperature flue gas desulfurization, denitrification and dust removal system according to claim 1, characterized in that, The return material system includes a return material hopper, a double-screw feeder and a gasification chute. The return material hopper is connected to the double-screw feeder below, and the double-screw feeder is connected to the gasification chute below. The gasification chute is communicated with the dry desulfurization tower.

7. A high-temperature flue gas desulfurization, denitrification and dust removal system according to claim 4, characterized in that, The desulfurizer storage and feeding system is communicated with a fluidizing air system. The fluidizing air system includes a fluidizing air blower and an electric heater. The fluidizing air blower and the electric heater are communicated with the desulfurizer bin, the weighing chute and the gasification chute through pipelines.

8. A high-temperature flue gas desulfurization, denitrification and dust removal system according to claim 1, characterized in that, The ash conveying system includes a conveying pipeline and a gas storage tank. A switching valve is arranged on the conveying pipeline, which can be directed to convey the materials collected from the dry desulfurization tower and the integrated dust and NOx removal equipment to the return material system or the waste ash storage system.

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