Dust collection and purification system for a gypsum board production line

Abstract

This utility model relates to the technical field of gypsum board production equipment, specifically to a dust collection and purification system for a gypsum board production line. The system includes a calcination unit, a multi-stage dust removal unit, a wet purification unit, a deep treatment unit, and a recycling module. The calcination unit comprises a combustion chamber and a calcination chamber connected in series. The multi-stage dust removal unit includes a dry electrostatic precipitator and a dust grading device connected in sequence, with the inlet of the dry electrostatic precipitator connected to the outlet of the calcination chamber. The wet purification unit includes a wet oxidation tower and a cyclone-driven desulfurization tower connected in sequence, with the inlet of the wet oxidation tower connected to the outlet of the multi-stage dust removal unit. The deep treatment unit includes a wet electrostatic precipitator, with its inlet connected to the outlet of the wet purification unit. The recycling module includes a waste heat recovery pipeline connected to the hot flue gas outlet of the combustion chamber, and a wastewater membrane treatment system connected to the deep treatment unit. This utility model can achieve efficient graded dust collection, deep purification of pollutants, and resource recycling.

Description

Technical Field

[0001] This utility model relates to the technical field of gypsum board production equipment, specifically to a dust collection and purification system for a gypsum board production line. Background Technology

[0002] During the production of gypsum board, the flue gas generated by gypsum calcination contains a large amount of dust (such as gypsum particles and smoke) and pollutants (SO2, NO). x Traditional processing systems (etc.) have the following problems:

[0003] Dust treatment is limited: dust is collected using only a single dust removal device without classifying and utilizing coarse and fine particles, resulting in waste of gypsum resources and a heavy load on subsequent processing.

[0004] Incomplete pollutant purification: When traditional wet desulfurization towers are connected in series with electrostatic precipitators, their efficiency in capturing submicron particles and droplets is insufficient, making it difficult to meet ultra-low emission requirements.

[0005] Energy consumption and resource waste: High-temperature flue gas is directly emitted or cooled by water without recovering waste heat, and desulfurization wastewater is not effectively treated, resulting in energy waste and secondary pollution.

[0006] While existing technologies offer solutions for reducing pollutants through multi-stage treatment (such as dry electrostatic precipitators combined with wet desulfurization), they lack systematic integration of dust classification and recovery, waste heat recycling, and closed-loop wastewater treatment. This invention provides a dust collection and purification system for a gypsum board production line. Through an integrated design encompassing calcination treatment, multi-stage dust removal, wet purification, deep treatment, and recycling, it achieves efficient dust classification and recovery, deep pollutant purification, and resource recycling. Utility Model Content

[0007] In view of this, the purpose of this utility model is to provide a dust collection and purification system for gypsum board production lines, so as to solve the problems of low dust treatment efficiency, resource waste and failure to meet environmental protection standards in the existing technology of gypsum board production lines.

[0008] To achieve the above objectives, this utility model provides the following technical solution:

[0009] A dust collection and purification system for a gypsum board production line includes:

[0010] The calcination treatment unit includes a combustion chamber and a calcination chamber. The combustion chamber is provided with a fuel inlet and a hot flue gas outlet. The calcination chamber is connected to the hot flue gas outlet through a hot flue gas pipe and is used for calcining gypsum powder.

[0011] A multi-stage dust removal unit includes a dry electrostatic precipitator and a dust classification device connected in sequence. The inlet of the dry electrostatic precipitator is connected to the outlet of the calcination chamber and is used to collect coarse dust particles. The dust classification device is used to separate the dust particles by size.

[0012] The wet purification unit includes a wet oxidation tower and a cyclone-mixing desulfurization tower connected in sequence, wherein the inlet of the wet oxidation tower is connected to the outlet of the multi-stage dust removal unit;

[0013] The deep treatment unit includes a wet electrostatic precipitator, the inlet of which is connected to the outlet of the wet purification unit;

[0014] The recycling module includes a waste heat recovery pipeline connected to the hot flue gas outlet of the combustion chamber, and a wastewater membrane treatment system connected to the deep treatment unit.

[0015] As a further embodiment of this utility model: the dust classification device includes a cyclone separator and a bag filter. The outlet of the dry electrostatic precipitator is connected to the cyclone separator and the waste heat recovery pipeline through a three-way pipe. The coarse powder outlet at the bottom of the cyclone separator is connected to the raw material inlet of the calcination chamber, and the fine powder outlet at the top is connected to the bag filter.

[0016] As a further embodiment of this utility model, the waste heat recovery pipeline includes a plate heat exchanger, one end of which is connected to a hot flue gas pipeline and the other end of which is connected to a dust removal flue gas return pipeline of a dry electrostatic precipitator, for heat exchange between the hot flue gas and the dust removal flue gas.

[0017] As a further improvement of this utility model, the dust removal flue gas return pipe is provided with a return fan and a flow regulating valve connected in sequence.

[0018] As a further embodiment of this utility model: the wastewater membrane treatment system includes a membrane filtration device and an evaporator crystallizer, the drain outlet of the wet electrostatic precipitator is connected to the inlet of the membrane filtration device, the clean water outlet of the membrane filtration device is connected to the spray system of the wet oxidation tower and the cyclone hybrid desulfurization tower, and the concentrated water outlet of the membrane filtration device is connected to the evaporator crystallizer.

[0019] By adopting the above technical solution, this utility model will have the following beneficial effects:

[0020] 1. High-efficiency dust classification and recycling: Through a multi-stage dust removal unit (dry electrostatic precipitator + dust classification device), coarse dust particles are first captured, and then the remaining dust is separated by particle size to achieve the classification and utilization of coarse and fine particles, avoiding the waste of gypsum resources caused by traditional single dust removal, while reducing the load of subsequent processing.

[0021] 2. Deep purification of pollutants: The wet purification unit (wet oxidation tower + cyclone hybrid desulfurization tower) and the deep treatment unit (wet electrostatic precipitator) work together. The wet oxidation tower oxidizes and denitrates, the desulfurization tower enhances gas-liquid mass transfer to remove sulfur and nitrates, and the wet electrostatic precipitator further captures submicron particles and mist droplets, solving the problem of insufficient capture of fine particles by traditional processes and meeting ultra-low emission requirements.

[0022] 3. Resource recycling: The recycling module recovers the waste heat of the flue gas through the waste heat recovery pipeline, reducing energy waste; the wastewater membrane treatment system performs membrane filtration and evaporation crystallization on the wastewater generated by the deep treatment unit, the clean water is recycled for the spray system, and the concentrated water crystallization by-products are utilized as resources, avoiding secondary pollution and realizing closed-loop wastewater treatment.

[0023] In summary, through its integrated design, this system achieves graded dust recycling, deep purification of pollutants, and efficient resource recycling, solving problems such as low dust treatment efficiency, resource waste, and failure to meet environmental protection standards in existing gypsum board production lines. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the dust collection and purification system for a gypsum board production line according to an embodiment of the present invention.

[0026] The correspondence between the labels and component names in the attached figures is as follows:

[0027] 11. Combustion chamber; 12. Calcination chamber; 21. Dry electrostatic precipitator; 22. Dust classification device; 221. Cyclone separator; 222. Bag filter; 31. Wet oxidation tower; 32. Cyclone hybrid desulfurization tower; 4. Wet electrostatic precipitator; 51. Waste heat recovery pipeline; 511. Plate heat exchanger; 512. Return fan; 513. Flow regulating valve; 52. Wastewater membrane treatment system; 521. Membrane filtration device; 522. Evaporator crystallizer. Detailed Implementation

[0028] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this invention. Therefore, the following description is to be considered exemplary in nature and not restrictive.

[0029] Please refer to Figure 1 In one embodiment of the dust collection and purification system for a gypsum board production line provided by this utility model, the dust collection and purification system for a gypsum board production line includes a calcination treatment unit, a multi-stage dust removal unit, a wet purification unit, a deep treatment unit, and a recycling module.

[0030] The calcination unit includes a combustion chamber 11 and a calcination chamber 12. The combustion chamber 11 is equipped with a fuel inlet and a hot flue gas outlet. The combustion chamber 11 and the hot flue gas outlet of the calcination chamber 12 are connected by a hot flue gas pipe (made of 310S stainless steel, with a temperature resistance of 1100℃) for calcining gypsum powder.

[0031] The multi-stage dust removal unit includes a dry electrostatic precipitator 21 and a dust classification device 22. The inlet of the dry electrostatic precipitator 21 is connected to the outlet of the calcination chamber 12 and is used to collect coarse dust particles. Specifically, the dry electrostatic precipitator 21 can adopt a horizontal plate structure with an internal high-voltage electric field (voltage 40-60kV). The flue gas velocity is controlled at 0.5-0.6m / s, and the collection efficiency for coarse particles >10μm is >99%. The dust classification device 22 is connected to the dry electrostatic precipitator 21 and is used to separate the dust particles by size.

[0032] The wet purification unit includes a wet oxidation tower 31 and a cyclone hybrid desulfurization tower 32. The inlet of the wet oxidation tower 31 is connected to the outlet of the multi-stage dust removal unit. The outlet of the wet oxidation tower 31 and the inlet of the cyclone hybrid desulfurization tower 32 are connected in series through a corrosion-resistant pipe (FRP material). The wet oxidation tower 31 is equipped with a spiral nozzle (atomization particle size 150-250μm). The cyclone hybrid desulfurization tower 32 forms a high-speed turbulent zone (flow velocity 15-20m / s) with the swirl plate and the Venturi throat, which enhances the gas-liquid mass transfer efficiency.

[0033] The deep treatment unit includes a wet electrostatic precipitator 4, whose inlet is connected to the outlet of the wet purification unit. Specifically, the wet electrostatic precipitator 4 can adopt a vertical tubular structure with an anode tube inner diameter of 150mm, a cathode wire of barbed type, a flue gas velocity of 2-3m / s, a collection efficiency of >99% for particles ≤0.1μm, and an outlet flue gas particulate matter concentration ≤10mg / m³.

[0034] The recycling module includes a waste heat recovery pipeline 51 connected to the hot flue gas outlet of the combustion chamber 11, and a wastewater membrane treatment system 52 connected to the deep treatment unit. The waste heat recovery pipeline 51 is used to recover the waste heat of the hot flue gas and reuse it. The wastewater membrane treatment system 52 can wash the wastewater and remove heavy metal ions and suspended solids through membrane filtration, so that the clean water is returned to the spray system and the concentrated water is evaporated and crystallized to obtain by-products (gypsum + salts) as raw materials for building materials.

[0035] As a preferred embodiment, the dust classification device 22 includes a cyclone separator 221 and a bag filter 222. The outlet of the dry electrostatic precipitator 21 is connected to the cyclone separator 221 and the waste heat recovery pipeline 51 via a three-way pipe. The coarse powder outlet at the bottom of the cyclone separator 221 is connected to the raw material inlet of the calcination chamber 12, and the fine powder outlet at the top of the cyclone separator 221 is connected to the bag filter 222. Specifically, the cyclone separator 221 can adopt a downflow structure with a cylinder diameter of 1.2m, a cone angle of 60°, an inlet air velocity of 18m / s, and a separation efficiency of >95% for 50μm particles. A star-shaped discharge valve (sealing pressure ≤0.05MPa) is installed at the coarse powder outlet to prevent flue gas leakage. The 222 bag filter can be equipped with PTFE filter bags (filtration accuracy 1μm), uses pulse jet cleaning (air pressure 0.4-0.6MPa), and can handle an air volume of 5000-10000m³ / h. After fine powder is collected, it is sent to the connected gypsum powder silo via a screw conveyor to realize the resource utilization of dust.

[0036] As a preferred embodiment, the waste heat recovery pipeline 51 includes a plate heat exchanger 511. One end of the plate heat exchanger 511 is connected to the hot flue gas pipeline, and the other end is connected to the dust removal flue gas return pipeline of the dry electrostatic precipitator 21, for heat exchange between the hot flue gas and the dust removal flue gas. The heat exchange area of ​​the plate heat exchanger 511 is 200m², the plate material is 316L stainless steel, the maximum allowable pressure drop is 50kPa, the hot flue gas and the dust removal flue gas are arranged in countercurrent, and the heat recovery is ≥500kW when the temperature difference is ≥150℃.

[0037] Furthermore, the flue gas return duct is equipped with a return fan 512 and a flow regulating valve 513 connected in sequence. The return fan 512 is a high-temperature resistant centrifugal fan (temperature resistance 200℃, air volume 10000-20000m³ / h), equipped with a frequency converter (adjustment range 0-50Hz), which can automatically adjust the speed according to the oxygen content of the combustion chamber 11 (target excess coefficient 1.7-2); the flow regulating valve 513 is an electric butterfly valve (adjustment accuracy ±2%), which is linked with the temperature sensor of the combustion chamber 11. When the flue gas temperature is >650℃, the valve is automatically opened to increase the return flow, and the cooling rate is ≤50℃ / min.

[0038] As a preferred embodiment, the wastewater membrane treatment system 52 includes a membrane filtration device 521 and an evaporator crystallizer 522. The drain outlet of the wet electrostatic precipitator 4 is connected to the inlet of the membrane filtration device 521. The clean water outlet of the membrane filtration device 521 is connected to the spray system of the wet oxidation tower 31 and the cyclone-driven desulfurization tower 32. The concentrated water outlet of the membrane filtration device 521 is connected to the evaporator crystallizer 522. The membrane filtration device 521 adopts a cross-flow filtration mode, the membrane module is a ceramic membrane (pore size 0.5μm, membrane area 100m²), the design flux is 50-80L / (m²・h), and it is equipped with a pulse backwashing system (compressed air + clean water, backwashing frequency 30min / time), which can reduce the suspended solids in the wastewater from the wet electrostatic precipitator 4 from 500mg / L to ≤10mg / L. The evaporator crystallizer 522 is a forced circulation type with a processing capacity of 5-10 m³ / d and an evaporation temperature of 80-90℃. After crystallization, the concentrated water yields calcium sulfate dihydrate with a purity of >90%, which can be used as a raw material for gypsum board production or building gypsum, achieving zero wastewater discharge.

[0039] It should be noted that the aforementioned dry electrostatic precipitator 21, cyclone separator 221, bag filter 222, wet oxidation tower 31, cyclone hybrid desulfurization tower 32, wet electrostatic precipitator 4, plate heat exchanger 511, membrane filter device 521, and evaporator crystallizer 522 are all existing technologies, and their detailed structures and working principles will not be elaborated here.

[0040] The method of use or working principle of this utility model is as follows:

[0041] 1. Calcination treatment:

[0042] Fuel burns in combustion chamber 11 to produce high-temperature hot flue gas, and ammonia water is injected simultaneously for SNCR denitrification. The hot flue gas enters calcination chamber 12 and comes into contact with gypsum powder to complete calcination and dehydration, generating mixed flue gas containing a large amount of dust.

[0043] 2. Multi-stage dust removal:

[0044] The mixed flue gas first passes through a dry electrostatic precipitator 21 to collect coarse dust particles >10μm (such as gypsum blocks and large particulate dust). A portion of this dust is then returned to the combustion chamber 11 via a return fan 512 to regulate temperature and oxygen content, while the other portion enters a cyclone separator 221. In the cyclone separator 221, gypsum particles >50μm settle to the bottom due to centrifugal force and are returned to the calcination chamber 12 for reuse via a star-shaped discharge valve. Fine powder ≤50μm is carried by the airflow into a bag filter 222, where it is collected after filtration through PTFE filter bags and used to prepare gypsum-based materials.

[0045] 3. Wet purification:

[0046] Oxidation and denitrification: The dust removal flue gas passes through the wet oxidation tower 31 and comes into contact with sodium chlorite spray liquid inside the oxidation tower. NO is oxidized to NO2, creating conditions for subsequent desulfurization and denitrification.

[0047] Desulfurization and demisting: Dust-removed flue gas enters the cyclone-mixing desulfurization tower 32, where it forms high-speed turbulence through the cyclone plates and Venturi throat, fully mixing with the Ca(OH)2 slurry to remove SO2 and NO2. The top baffle demister intercepts droplets >5μm, reducing the humidity of the flue gas.

[0048] 4. Depth Filtering:

[0049] After desulfurization, the flue gas enters the wet electrostatic precipitator 4, where it passes through a vertical tubular electrode and a pulse spray device. The high-voltage electric field captures submicron particles (≤0.1μm) and fine droplets, ultimately achieving a particulate matter concentration of ≤10mg / m³, meeting ultra-low emission requirements, and is then discharged through the chimney.

[0050] 5. Recycling:

[0051] Waste heat recovery: Plate heat exchanger 511 transfers the heat of hot flue gas to the return dust removal flue gas, increasing the temperature of the return dust removal flue gas. The return dust removal flue gas enters the combustion chamber 11 through the return fan 512 and mixes with the combustion air before entering the combustion zone, reducing the energy consumption used to heat the air during fuel combustion.

[0052] Wastewater treatment: The wastewater from the wet electrostatic precipitator 4 is separated into clean water and concentrated water by the ceramic membrane filter device 521. The clean water is returned to the wet purification unit spray system for recycling; the concentrated water is treated by the evaporator crystallizer 522 to obtain gypsum by-product, achieving zero wastewater discharge.

[0053] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A dust collection and purification system for a gypsum board production line, characterized in that, include: The calcination treatment unit includes a combustion chamber (11) and a calcination chamber (12). The combustion chamber (11) is provided with a fuel inlet and a hot flue gas outlet. The calcination chamber (12) is connected to the hot flue gas outlet through a hot flue gas pipe and is used for calcining gypsum powder. The multi-stage dust removal unit includes a dry electrostatic precipitator (21) and a dust classification device (22) connected in sequence. The inlet of the dry electrostatic precipitator (21) is connected to the outlet of the calcination chamber (12) for collecting coarse dust particles. The dust classification device (22) is used to separate the dust particles by size. The wet purification unit includes a wet oxidation tower (31) and a cyclone-mixed desulfurization tower (32) connected in sequence. The inlet of the wet oxidation tower (31) is connected to the outlet of the multi-stage dust removal unit. The deep treatment unit includes a wet electrostatic precipitator (4), the inlet of which is connected to the outlet of the wet purification unit; The recycling module includes a waste heat recovery pipeline (51) connected to the hot flue gas outlet of the combustion chamber (11), and a wastewater membrane treatment system (52) connected to the deep treatment unit.

2. The dust collection and purification system for a gypsum board production line according to claim 1, characterized in that, The dust classification device (22) includes a cyclone separator (221) and a bag filter (222). The outlet of the dry electrostatic precipitator (21) is connected to the cyclone separator (221) and the waste heat recovery pipeline (51) through a three-way pipe. The coarse powder outlet at the bottom of the cyclone separator (221) is connected to the raw material inlet of the calcination chamber (12), and the fine powder outlet at the top is connected to the bag filter (222).

3. The dust collection and purification system for a gypsum board production line according to claim 1, characterized in that, The waste heat recovery pipeline (51) includes a plate heat exchanger (511), one end of which is connected to the hot flue gas pipeline and the other end is connected to the dust removal flue gas return pipeline of the dry electrostatic precipitator (21) for heat exchange between the hot flue gas and the dust removal flue gas.

4. The dust collection and purification system for a gypsum board production line according to claim 3, characterized in that, The dust removal flue gas return pipe is equipped with a return fan (512) and a flow regulating valve (513) connected in sequence.

5. The dust collection and purification system for a gypsum board production line according to claim 1, characterized in that, The wastewater membrane treatment system (52) includes a membrane filter (521) and an evaporator crystallizer (522). The drain outlet of the wet electrostatic precipitator (4) is connected to the inlet of the membrane filter (521). The clean water outlet of the membrane filter (521) is connected to the spray system of the wet oxidation tower (31) and the cyclone hybrid desulfurization tower (32). The concentrated water outlet of the membrane filter (521) is connected to the evaporator crystallizer (522).

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