Waste gas treatment system

Abstract

Disclosed in the present invention is a waste gas treatment system, at least comprising a fume treatment system and an oil mist treatment system. The fume treatment system comprises a gas collection hood, fume ductwork, a cyclone dust collector, a bag filter and a first fan, wherein the gas collection hood, which is used for collecting fumes, is arranged above the area where fumes / dust are generated; the gas collection hood is connected to the cyclone dust collector via the fume ductwork, the cyclone dust collector, the bag filter and the first fan are connected in sequence, and the first fan is connected to a first exhaust stack. The oil mist treatment system comprises an oil mist collection hood, oil mist ductwork, a pneumatic cyclone tower, an electrostatic adsorption device, an activated carbon adsorption device, and a second fan, wherein the oil mist collection hood is connected to the pneumatic cyclone tower via the oil mist ductwork, the pneumatic cyclone tower, the electrostatic adsorption device, the activated carbon adsorption device, and the second fan are connected in sequence, and the second fan is connected to a second exhaust stack. The present invention enables effective removal of various waste gases generated during enterprise production and processing.

Description

Exhaust gas treatment system Technical Field

[0001] This invention relates to the field of waste gas treatment technology, and in particular to a waste gas treatment system. Background Technology

[0002] The production processes involved in the enterprise, such as machining, aluminum alloy melting, die casting demolding, and shot blasting, generate waste gases such as oil mist, fumes from aluminum melting, and non-methane hydrocarbons. According to the relevant emission standards in the "Integrated Emission Standard for Air Pollutants" (DB31 / 933-2015) and the "Emission Standard for Air Pollutants in the Foundry Industry" (GB39726-2020), the waste gases emitted by the enterprise must be treated to meet the emission standards.

[0003] Currently, there is no specialized equipment to remove various waste gases, including smoke and oil mist, generated during the production and processing of enterprises. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides an exhaust gas treatment system to solve the issues in the prior art.

[0005] An exhaust gas treatment system, characterized in that it includes at least a dust treatment system and an oil mist treatment system;

[0006] The dust treatment system includes a dust collection hood, dust pipelines, a cyclone dust collector, a bag filter, and a first fan. The dust collection hood is used to collect dust and is installed above the dust / powder generation area. The dust collection hood is connected to the cyclone dust collector through the dust pipelines. The cyclone dust collector, the bag filter, and the first fan are connected in sequence. The first fan is connected to the first exhaust stack.

[0007] The oil mist treatment system includes an oil mist collection hood, an oil mist pipeline, a pneumatic cyclone tower, an electrostatic adsorption device, an activated carbon adsorption device, and a second fan. The oil mist collection hood is connected to the pneumatic cyclone tower through the oil mist pipeline. The pneumatic cyclone tower, the electrostatic adsorption device, the activated carbon adsorption device, and the second fan are connected in sequence. The second fan is connected to the second exhaust stack.

[0008] Preferably, the air collection hood is a rotating dust collection hood, and the air inlet of the hood is provided with rotating blades.

[0009] Preferably, the cyclone dust collector includes an air inlet, an exhaust outlet, a gas spiral descending section, an accelerating spiral descending section, and a dust outlet. The gas spiral descending section is a hollow cylinder, the air inlet is located in the gas spiral descending section, the accelerating spiral descending section is a hollow truncated cone, and the dust outlet is located in the accelerating spiral descending section.

[0010] Preferably, the pneumatic cyclone tower is provided with a water tank, a cyclone layer, a spray layer, and an air outlet assembly from bottom to top; the water in the water tank is pumped to the spray layer by a water pump, the cyclone layer is provided with a gas inlet, and the air outlet assembly is provided with an environmentally friendly filler water-proof layer.

[0011] Smoke and dust and natural gas combustion exhaust generated during the enterprise's production and processing are collected by a gas collection hood, treated by a cyclone dust collector and a bag filter, and then discharged at high altitude through the first exhaust stack.

[0012] Oil mist containing non-methane total hydrocarbons is led through an oil mist pipeline to a pneumatic cyclone tower, an electrostatic adsorption device, and an activated carbon adsorption device for sequential treatment. The exhaust gas is then discharged at high altitude through a second exhaust stack.

[0013] The waste gas generated from wastewater treatment first enters the alkaline scrubbing tower. After being treated by the alkaline scrubbing tower, it then passes through the pneumatic cyclone tower, electrostatic adsorption device, and activated carbon adsorption device in sequence before being discharged into the atmosphere through the second exhaust stack.

[0014] This invention can effectively remove various waste gases generated during the production and processing of enterprises. Attached Figure Description

[0015] Figure 1 is a schematic diagram of the waste gas treatment system.

[0016] Figure 2 is a schematic diagram of the gas collection hood.

[0017] Figure 3 is a schematic diagram of a cyclone dust collector.

[0018] Figure 4 is a partial schematic diagram of the dust treatment system.

[0019] Figure 5 is a partial schematic diagram of the oil mist treatment system.

[0020] Figure 6 is a schematic diagram of an aerodynamic cyclone tower.

[0021] Figure 7 is a schematic diagram of an activated carbon adsorption device. Detailed Implementation

[0022] The technical solution of the present invention will now be described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them; and the structures shown in the accompanying drawings are merely illustrative and do not represent physical objects. It should be noted that all other embodiments obtained by those skilled in the art based on these embodiments of the present invention are within the scope of protection of this application.

[0023] It should be noted that, in this document, the term "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical or equivalent elements in the process, method, article, or apparatus that includes said element.

[0024] The terms "upper," "lower," "inner," and "outer" do not constitute absolute spatial relationship restrictions, but are merely concepts of relative position. This is something that anyone skilled in the art can understand.

[0025] Referring to Figures 1-7, the exhaust gas treatment system includes a dust treatment system 100 and an oil mist treatment system 200;

[0026] The dust collection system 100 includes a dust collection hood 110, a dust duct 120, a cyclone dust collector 130, a bag filter 140, and a first fan 150.

[0027] The gas collection hood is used to collect smoke and dust. There can be multiple hoods, which are arranged above the smoke / dust generating area (such as melting furnace, holding furnace), as shown in Figure 2. The gas collection hood is a rotary dust collection hood, that is, the air inlet of the hood is equipped with rotating blades 111 to accelerate the gas intake. All gas collection hoods are connected to the cyclone dust collector 130 through the smoke and dust pipeline 120. The cyclone dust collector 130, the bag dust collector 140, and the first fan 150 are connected in sequence. The first fan 150 is connected to the first exhaust stack 160.

[0028] The 120 flue gas duct is constructed of 304 stainless steel and includes straight pipes, branch pipes, elbows, connectors, clamps, screws, seals, and pipe support and fixing materials. It can withstand a positive pressure of +3000Pa, a negative pressure of -5000Pa, and a temperature range of -30℃ to +100℃. The straight pipe thickness is 1.0~1.2 mm, depending on the pipe diameter.

[0029] As shown in Figure 3, the cyclone dust collector 130 mainly consists of an air inlet 131, an exhaust outlet 132, a gas spiral descending section 133 (hollow cylindrical shape), an accelerating spiral descending section 134 (frustum-shaped), and a dust outlet 135. When the airflow carrying dust enters through the air inlet 131, the mixture rotates clockwise downwards along the sidewall of the accelerating spiral descending section (the solid line in the figure). Because the accelerating spiral descending section is frustum-shaped, the gas mixture undergoes accelerated spiral descending to the dust outlet 135. At the dust outlet 135, the dust is thrown out of the cyclone cone by the gas (lower arrow in the figure), while the gas spirals upwards along the center line and is discharged from the exhaust outlet (dashed line in the figure).

[0030] The baghouse dust collector 140 primarily relies on filter bags to filter dust-laden gas. When the dust-laden gas passes through the filter bags, larger particles settle to the bottom due to gravity, while smaller particles are trapped by the filter bags through diffusion and sieving, thus purifying the gas. A pulse-jet baghouse dust collector can be selected; however, this is an existing structure and will not be described in detail here.

[0031] After the first fan 150 is started, the airflow containing smoke and dust enters the cyclone dust collector 130 and the bag filter 140 through the dust collection hood 110 and the dust pipe 120 for dust removal. Then the gas is discharged through the first exhaust pipe 160.

[0032] The oil mist treatment system 200 includes an oil mist collection hood 210, an oil mist pipeline 220, a pneumatic cyclone tower 230, an electrostatic adsorption device 240, an activated carbon adsorption device 250, and a second fan 260. The oil mist collection hood 210 is a square gas collection hood, and there can be multiple hoods, which are arranged above the oil mist generation area.

[0033] The oil mist collection hood 210 is connected to the pneumatic cyclone tower 230 through the oil mist pipeline 220. The pneumatic cyclone tower 230, the electrostatic adsorption device 240, the activated carbon adsorption device 250, and the second fan 260 are connected in sequence. The second fan 260 is connected to the second exhaust pipe 270.

[0034] The 220 oil mist duct uses a 304 stainless steel duct structure. The complete set includes straight pipes, branch pipes, elbows, connectors, pipe clamps, screws, seals, and pipe support and fixing materials. It can withstand a positive pressure of +3000Pa, a negative pressure of -5000Pa, and a temperature range of -30℃ to +100℃. The straight pipe thickness is 1.0~1.2 mm, depending on the pipe diameter.

[0035] Referring to Figure 6, the pneumatic cyclone tower 230 is arranged from bottom to top as follows: a water tank 231, a cyclone layer 232, a spray layer 233, and an air outlet assembly 234. Water in the water tank 231 is pumped to the spray layer 233 by a water pump 235. The cyclone layer 232 has a gas inlet. When the exhaust gas enters the cyclone layer 232 under the traction of a negative pressure fan, the gas is confined by the inner wall of the tower, thus forming a rotating flow. The exhaust gas, cyclone, and water falling from the spray layer undergo a gas-liquid emulsification reaction during high-speed rotation, fully mixing the exhaust gas and rotating liquid, achieving gas-liquid separation under centrifugal force. The separated dust particles settle to the bottom of the water tank. The air outlet assembly 234 is equipped with an environmentally friendly filling material water-proof layer. The separated gas enters the environmentally friendly filling material water-proof layer and then enters the subsequent exhaust gas treatment equipment. After treatment, the purification rate can reach over 95%, and the purified exhaust gas meets emission requirements, lower than national emission standards.

[0036] This equipment can effectively remove water-soluble gases such as hydrogen chloride (HCl), hydrogen fluoride (HF), ammonia (NH3), sulfuric acid mist (H2SO4), chromic acid mist (CrO3), hydrogen cyanide (HCN), alkaline vapor (NaOH), hydrogen sulfide (H2S), and formaldehyde (HCHO).

[0037] The electrostatic adsorption device 240 uses a high-voltage electrostatic field to ionize gas molecules in the air, generating a large number of negative and positive ions. These ions move towards the electrodes under the influence of the electric field, colliding with dust particles in the air and charging them. The charged dust particles then move towards the electrodes of opposite polarity under the influence of the electric field and are eventually adsorbed onto the electrodes, thus achieving dust removal. This equipment is a conventional dust removal device and will not be described in detail here.

[0038] Referring to Figure 7, the activated carbon adsorption device 250 includes a tank 251, with inlets and outlets (252, 253) at both ends of the tank 251, and an activated carbon adsorption plate device 254 installed inside the tank.

[0039] The activated carbon adsorption plate device 254 uses activated carbon with a large specific surface area and high adsorption performance as an adsorbent to adsorb atmospheric pollutants in organic waste gas and discharge clean air.

[0040] The mechanism of activated carbon adsorption for treating waste gas mainly includes two aspects: physical adsorption and chemical adsorption.

[0041] Physical adsorption primarily occurs during the removal of impurities from liquid and gas phases by activated carbon. The porous structure of activated carbon provides a large surface area, making it highly effective at absorbing and collecting impurities. Due to the presence of unbalanced and unsaturated molecular attraction or chemical bonding forces on the surface of activated carbon adsorbents, gas molecules are attracted to this solid surface when in contact with gas, causing them to concentrate and remain on the solid surface – a phenomenon known as adsorption. By utilizing the adsorption capacity of a solid surface, waste gas is brought into contact with a porous solid material with a large surface area. Pollutants in the waste gas are adsorbed onto the solid surface, separating them from the gas mixture and achieving purification.

[0042] Besides physical adsorption, chemical reactions also frequently occur on the surface of activated carbon. Activated carbon not only contains carbon, but also contains small amounts of chemically bonded functional groups of oxygen and nitrogen on its surface, such as hydroxyl groups, phenols, lactones, quinones, and ethers. These surface oxides or complexes can chemically react with the adsorbed substances, thereby binding and accumulating on the surface of the activated carbon.

[0043] In addition, the exhaust gas treatment system also includes an alkaline scrubbing tower 300. The inlet of the alkaline scrubbing tower 300 is connected to the gas collection hood of the wastewater treatment station, and the outlet of the alkaline scrubbing tower 300 is connected to the air inlet of the pneumatic cyclone tower 230. The exhaust gas generated from the wastewater treatment first enters the alkaline scrubbing tower 300. After being treated by the alkaline scrubbing tower, it is then led to the pneumatic cyclone tower 230 and the activated carbon adsorption device 250. The exhaust gas is discharged at high altitude through the second exhaust stack 270.

[0044] When particulate pollutants in the airflow come into contact with the washing liquid, droplets or liquid films diffuse and adhere to the airflow particles, or humidify the particles, allowing them to be separated and removed by gravity, inertia, and other forces. Gaseous pollutants are transported into the washing liquid through turbulence, molecular diffusion, mass transfer, and chemical reactions, achieving separation from the incoming gas. Chemical substances can be added to the washing liquid to control gaseous odorous substances through absorption. The equipment itself includes the main body, a packing layer, a demister layer, circulating water spray pipes, and a circulating water tank.

[0045] The waste gas is treated in an alkaline scrubbing tower 300 using a counter-current gas-liquid absorption method. Liquid is sprayed downwards from the top of the tower as a mist (or small water droplets), while the waste gas flows counter-currently from the bottom, achieving gas-liquid contact. This treatment method cools the waste gas, conditions the gas, and removes particles. After further treatment in a demister section, the gas is released into the atmosphere.

[0046] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A waste gas treatment system, characterized in that, It should include at least a fume extraction system and an oil mist extraction system; The dust treatment system includes a dust collection hood, dust pipelines, a cyclone dust collector, a bag filter, and a first fan. The dust collection hood is used to collect dust and is installed above the dust / powder generation area. The dust collection hood is connected to the cyclone dust collector through the dust pipelines. The cyclone dust collector, the bag filter, and the first fan are connected in sequence. The first fan is connected to the first exhaust stack. The oil mist treatment system includes an oil mist collection hood, an oil mist pipeline, a pneumatic cyclone tower, an electrostatic adsorption device, an activated carbon adsorption device, and a second fan. The oil mist collection hood is connected to the pneumatic cyclone tower through the oil mist pipeline. The pneumatic cyclone tower, the electrostatic adsorption device, the activated carbon adsorption device, and the second fan are connected in sequence. The second fan is connected to the second exhaust stack.

2. The waste gas treatment system according to claim 1, characterized in that, The air collection hood is a rotating dust collection hood, and its air inlet is equipped with rotating blades.

3. The waste gas treatment system according to claim 1, characterized in that, The cyclone dust collector includes an air inlet, an exhaust outlet, a gas spiral descending section, an accelerating spiral descending section, and a dust outlet. The gas spiral descending section is a hollow cylinder, the air inlet is located in the gas spiral descending section, the accelerating spiral descending section is a hollow truncated cone, and the dust outlet is located in the accelerating spiral descending section.

4. The waste gas treatment system according to claim 1, characterized in that, The pneumatic cyclone tower is provided with a water tank, a cyclone layer, a spray layer, and an air outlet assembly from bottom to top. Water in the water tank is pumped to the spray layer by a water pump. The cyclone layer is provided with a gas inlet, and the air outlet assembly is provided with an environmentally friendly water-proof filling material layer.

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