Small-air-volume VOC waste gas treatment system

Abstract

The invention discloses a small-air-volume VOC waste gas treatment system which comprises a first flame arrester, a gas mixing chamber, a second flame arrester, a glass rotameter, microwave treatment equipment, a variable-frequency centrifugal fan, a smell adjusting box and a gas discharge outlet which are sequentially connected behind a waste gas inlet, the device further comprises a variable-frequency air supplement machine which is connected with the gas air mixing chamber and used for diluting high-concentration VOC waste gas in the gas air mixing chamber. The microwave treatment equipment is used for decomposing pollution components in the VOC waste gas. The device has the advantages of simple structure, high treatment efficiency, safety, reliability, stable treatment effect and low energy consumption.

Description

Technical Field

[0001] The present invention belongs to the technical field of oilfield waste gas treatment, and particularly relates to a small-air-volume VOC waste gas treatment system. Background Art

[0002] In the industrial production field, a large amount of volatile organic compounds (VOCs) will be generated. The characteristics of VOCs are large quantity, wide variety, complex composition, irregular emission concentration, large volatility of organic matter content, flammable and having certain toxicity, and some even have bad smell. The emission of VOC waste gas not only causes waste of resources and increases production costs, but also causes serious environmental pollution. Volatile organic compounds VOC can react with NOx in the atmosphere to form photochemical smog, causing secondary pollution and endangering human health and the growth of crops. Most VOCs are flammable and explosive, and are prone to fire or explosion accidents when discharged at high concentrations. In addition, the emission of certain VOCs such as chlorofluorocarbons will also cause the destruction of the ozone layer and the greenhouse effect. The irritation and toxicity of organic gases seriously endanger human health, and sometimes cause acute poisoning or even death under high concentration. It mainly comes from processes such as coal chemical industry, petrochemical industry, and paint manufacturing. Therefore, the main object of waste gas treatment in the current petrochemical field is VOC waste gas.

[0003] The existing methods for treating VOC waste gas mainly include thermal destruction method, pressure swing adsorption separation and purification technology, adsorption method, oxidation treatment method, etc.

[0004] At present, the following problems exist in the operation process:

[0005] The commonly used treatment methods for VOC are combustion treatment method and oxidation treatment method. The combustion treatment method is suitable for the treatment of VOC with high concentration and high volume emission, and the treatment efficiency is higher than 90%. However, it still needs to consume energy, and the required catalyst is expensive, resulting in high treatment costs. Industrial waste gas contains a large amount of O2. Some enterprises use catalytic combustion process for tail gas treatment. However, due to the immaturity of the catalytic combustion process, multiple explosion accidents have occurred during the operation of the tail gas recovery equipment. The oxidation treatment method is suitable for the treatment of VOC with medium and high concentration and medium and small volume emission. It has high requirements for environmental conditions such as temperature and humidity. At the same time, the selection and dosage of oxidants will also affect the treatment cost and safety, and there is also the problem of low treatment efficiency. In the petrochemical field, especially in the waste gas of the oilfield field, there are a large number of light components such as C1-C3. The light components such as C1-C3 cannot be removed by ordinary adsorption and condensation processes, resulting in unqualified waste gas treatment.

[0006] The current VOC waste gas treatment technology has not achieved high treatment efficiency, good safety performance, and simple structure at the same time, and there is still room for innovation. Summary of the Invention

[0007] In view of the above problems, the present invention proposes a small-air-volume VOC waste gas treatment system.

[0008] The object of the present invention can be achieved by the following solutions:

[0009] The present invention provides a small-air-volume VOC waste gas treatment system, including: a first flame arrester, a gas mixing chamber, a second flame arrester, a glass rotameter, a microwave treatment device, a variable-frequency centrifugal fan, an odor adjustment box, and a gas discharge outlet, which are sequentially connected and arranged after the waste gas inlet;

[0010] It further includes a variable-frequency make-up air fan, and the variable-frequency make-up air fan is connected to the gas mixing chamber for diluting the high-concentration VOC waste gas in the gas mixing chamber;

[0011] The microwave treatment device is used to decompose the pollution components in the VOC waste gas.

[0012] Further, the microwave treatment device at least includes: an electrodeless ultraviolet lamp, a microwave source, a filtering chamber, and an electrostatic dust removal module; the electrodeless ultraviolet lamp, the microwave source, and the electrostatic dust removal module are arranged between the inlet and outlet of the microwave treatment device; the filtering chamber is connected to the inlet of the microwave treatment device; wherein, the number of the electrodeless ultraviolet lamps is at least 2, and the number of the microwave sources is at least 3.

[0013] Further, the filtering chamber includes a filter and a uniform air distribution plate; the filter is used to filter large particles in the VOC waste gas, and the uniform air distribution plate is used to make the VOC waste gas flow evenly.

[0014] Further, a metal mesh is arranged at the outlet of the microwave treatment device.

[0015] Further, the material of the metal mesh is 304 stainless steel.

[0016] Further, the electrodeless ultraviolet lamp is an electrodeless ultraviolet lamp with a wavelength of 185 nm.

[0017] Further, in the same time period, only two of the microwave sources work.

[0018] Further, it further includes: a control cabinet; the control cabinet is used to control the electrical equipment of the small-air-volume VOC waste gas treatment system.

[0019] Further, it further includes: a first gas concentration sensor, a second gas concentration sensor, and a third gas concentration sensor;

[0020] The first gas concentration sensor is arranged between the gas mixing chamber and the second flame arrester; the second gas concentration sensor is arranged between the frequency conversion centrifugal fan and the odor adjustment box; the third gas concentration sensor is arranged after the odor adjustment box.

[0021] Further, an ozone removal catalyst is arranged in the odor adjustment box.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] (1) High treatment efficiency: In the petrochemical field, especially for light components such as C1-C3 in oilfield waste gas, ordinary adsorption and condensation processes cannot remove them, resulting in unqualified waste gas treatment. The treatment effect of the technical solution of the present application can reach more than 90%;

[0024] (2) Safe and reliable: Compared with the catalytic combustion process, there is no open flame in the treatment process of the present application, and no explosion accident will occur;

[0025] (3) Stable treatment effect: The present application has low requirements for environmental conditions such as temperature and humidity, and the treatment effect is relatively stable;

[0026] (4) Low energy consumption: Compared with common processes such as condensation and adsorption, the power of this system is low and the energy consumption is small.

[0027] Other features and advantages of the present invention will be described in the following description of the specification, and some of them will be obvious from the description of the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures pointed out in the specification, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 Shows a schematic diagram of a small air volume VOC waste gas treatment system provided by an embodiment of the present invention;

[0030] Figure 2 Shows a schematic structural diagram of a microwave treatment system provided by an embodiment of the present invention;

[0031] In the figure, 1 - microwave source, 2 - power distribution control unit, 3 - electrostatic precipitator power supply, 4 - air inlet, 5 - air outlet, 6 - fan, 7 - filtration chamber, 8 - electrostatic precipitator module, 9 - microwave power chamber, 10 - metal mesh, 11 - electrodeless ultraviolet lamp, 101 - gas mixing chamber, 102 - glass rotameter, 103 - microwave treatment equipment, 104 - variable frequency centrifugal fan, 105 - odor adjustment box, 106 - first flame arrester, 107 - second flame arrester, 108 - variable frequency make-up air fan, 109 - second gas concentration sensor, 110 - first gas concentration sensor, 111 - third gas concentration sensor. Specific embodiments

[0032] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] The embodiments of the present invention provide a small air volume VOC waste gas treatment system, including: a first flame arrester, a gas mixing chamber, a second flame arrester, a glass rotameter, microwave treatment equipment, a variable frequency centrifugal fan, an odor adjustment box and a gas discharge outlet, which are sequentially connected and arranged after the waste gas inlet;

[0034] It further includes a variable frequency make-up air fan, and the variable frequency make-up air fan is connected to the gas mixing chamber for diluting the high-concentration VOC waste gas in the gas mixing chamber;

[0035] The microwave treatment equipment is used for decomposing the pollution components in the VOC waste gas.

[0036] Compared with the prior art, the small air volume VOC waste gas treatment system provided by the embodiments of the present invention has the advantages of simple structure, high treatment efficiency, safety and reliability, stable treatment effect and low energy consumption.

[0037] Refer to Figure 1 , and the components of a small air volume VOC waste gas treatment system provided by the embodiments of the present invention will be described.

[0038] A first flame arrester 106 is provided behind the waste gas inlet. The first flame arrester 106 can block the possible burning situation on the intake side. The first flame arrester 106 can quickly block the flame, thus effectively preventing the spread of fire. A gas mixing chamber 101 is provided behind the first flame arrester 106. The gas mixing chamber 101 is connected to a variable-frequency air supply fan 108. A second flame arrester 107 is provided behind the gas mixing chamber 101. The variable-frequency air supply fan 108 is used to dilute the high-concentration VOC waste gas in the gas mixing chamber 101 to adapt to the processing capacity of subsequent equipment, and at the same time avoid the explosion range of combustible gases, making the whole treatment process safer and more reliable. In the gas mixing chamber 101, the positive-pressure VOC waste gas from the waste gas inlet is diluted and pressure-regulated by fresh air to obtain a harmonized waste gas that meets the working conditions of subsequent treatment equipment. The second flame arrester 107 can block the possible burning situation on the outlet side of the gas mixing chamber 101.

[0039] A first gas concentration sensor 110 is provided at the measurement hole between the gas mixing chamber 101 and the second flame arrester 107. The first gas concentration sensor 110 is used to detect the concentration of the diluted VOC waste gas.

[0040] A glass rotameter 102 is provided behind the second flame arrester 107. The glass rotameter 102 can adjust the flow rate of the VOC waste gas. Specifically, adjusting the flow rate of the VOC waste gas is achieved by adjusting the flow switch on the glass rotameter 102.

[0041] A microwave treatment device 103 is provided behind the glass rotameter 102. The microwave treatment device 103 is used to decompose the pollution components in the VOC waste gas. The glass rotameter 102 can adjust the flow rate of the VOC waste gas entering the microwave treatment device 103.

[0042] Refer to Figure 2 , which is a schematic structural diagram of the microwave treatment device 103 provided by an embodiment of the present invention. Combining with the embodiment of the present invention, the microwave treatment device 103 at least includes an electrodeless ultraviolet lamp 11, a microwave source 1, a filter chamber 7 and an electrostatic precipitation module 8. At the same time, the electrodeless ultraviolet lamp 11, the microwave source 1 and the electrostatic precipitation module 8 are arranged between the intake port 4 and the outlet port 5 of the microwave treatment device 103. The filter chamber 7 is connected to the intake port 4 and is arranged inside the cavity of the microwave treatment device 103.

[0043] The lamp tube of the electrodeless ultraviolet lamp 11 is filled with an inert gas. The lamp tube has no positive and negative poles. When the lamp tube is placed in a microwave field, microwave ultraviolet light will be generated. Optionally, the number of electrodeless ultraviolet lamps is at least 2. Preferably, the electrodeless ultraviolet lamp 11 is an electrodeless ultraviolet lamp in the 185nm band. The microwave source 1 is a device that generates microwave energy. The microwave source 1 can optionally be a continuous wave source or a pulse modulation wave source. The number of microwave sources 1 is at least 3. In the same time period, only two microwave sources 1 are working, and the working time of the two simultaneously working microwave sources 1 is 3 minutes. The purpose is to protect the microwave source 1 and extend its service life.

[0044] The microwave cracking technology is to convert microwave energy into the internal energy of gas molecules in a microwave field, so that they are excited and ionized to generate plasma. The lamp tube of the electrodeless ultraviolet lamp 11 emits microwave ultraviolet light. While directly cracking the components of pollutants, photons and plasma also excite the air to generate active groups such as ozone and hydroxyl groups. The catalytic synergistic effect of microwaves can effectively increase the collision probability between molecules and improve the degradation efficiency of VOC waste gas. The ultraviolet light emitted by the electrodeless ultraviolet lamp 11 can also secondarily excite the pollutants that have not undergone degradation reactions. It can not only provide energy to bombard pollutant molecules to accelerate the reaction, but also degrade the excess ozone through the ultraviolet light itself, reducing secondary pollutants while improving the production efficiency of waste gas treatment, making the purification more thorough and improving the waste gas treatment effect.

[0045] The filtering chamber 7 is used to filter large particles in the VOC waste gas and make the VOC waste gas flow evenly in the filtering chamber 7, increasing the residence time of the VOC waste gas in the microwave treatment device 103 and improving the treatment efficiency. Specifically, the filtering chamber 7 includes a filter and a uniform air plate. The filter is used to filter large particles in the VOC waste gas, thus ensuring that the lamp tube of the electrodeless ultraviolet lamp 11 will not be broken by the particles in the VOC waste gas, playing a role in protecting the electrodeless ultraviolet lamp 11. Under the action of the uniform air plate, the VOC waste gas is evenly distributed, making the VOC waste gas flow evenly in the filtering chamber 7, increasing the residence time of the VOC waste gas inside the microwave treatment device 103 and improving the treatment efficiency.

[0046] The electrostatic dust removal module 8 is used to remove dust and particles in the gas, reducing their impact on the effect of microwave treatment of waste gas. A metal mesh 10 is provided at the gas outlet 5 of the microwave treatment device 103. The metal mesh 10 is used to prevent microwave leakage. In a specific embodiment, the material of the metal mesh 10 is preferably 304 stainless steel.

[0047] In combination with the embodiments of the present invention, the microwave treatment device 103 further includes a power distribution control unit 2, an electrostatic precipitation power supply 3, a fan 6, and a microwave power supply cavity 9. The power distribution control unit 2 is used to achieve the electrical control of the microwave treatment device 103, the electrostatic precipitation power supply 3 is used to achieve the electrical control of the electrostatic precipitation module 8, and the microwave power supply cavity 9 is used to achieve the electrical control of the microwave source 1. The fan 6 is used to make the VOC waste gas pass through the microwave treatment device 103. It is the core power device of the microwave treatment device 103, making the microwave treatment device 103 form a negative pressure device and providing the power required for the VOC waste gas to flow through the microwave treatment device 103. The cavity of the microwave treatment device 103 is made of metal material, and the preferred metal material is 304 stainless steel.

[0048] In combination with the embodiments of the present invention, refer to Figure 1 , a variable frequency centrifugal fan 104 is provided after the microwave treatment device 103. The variable frequency centrifugal fan 104 is the core power device of the whole system, making the whole system form a negative pressure system and providing the power required for the VOC waste gas and the treated gas to flow through the small air volume VOC waste gas treatment system. It should be noted that only one of the fan 6 in the microwave treatment device 103 and the variable frequency centrifugal fan 104 is used. If the microwave treatment device 103 is used alone, the fan 6 is enabled.

[0049] An odor adjustment box 105 is provided after the variable frequency centrifugal fan 104, and a gas discharge outlet is connected after the odor adjustment box 105. A second gas concentration sensor 109 is provided between the variable frequency centrifugal fan 104 and the odor adjustment box 105. The second gas concentration sensor 109 is arranged on the measurement hole between the variable frequency centrifugal fan 104 and the odor adjustment box 105, and the second gas concentration sensor 109 is used to measure the concentration of the treated gas.

[0050] The odor adjustment box 105 is provided with an ozone removal catalyst for treating the ozone flowing out of the microwave treatment device 103 to make the ozone content of the discharged gas meet the standards. Among them, according to the composition and structure types of the ozone catalyst, it can be divided into the following categories: metal catalysts, such as silver, palladium, copper, etc., which are mainly used for ozone reduction reactions; titanium dioxide catalysts, which have high oxidation activity and can be used to decompose ozone and oxidize harmful gases; activated carbon catalysts, which can adsorb and remove organic pollutants in the air due to their high porosity and specific surface area; composite catalysts, which are composed of different types of catalysts and have the ability to remove multiple harmful gases simultaneously. The action principle and types of the ozone removal catalyst are diverse and need to be selected according to specific requirements.

[0051] A third gas concentration sensor 111 is arranged on the measurement hole between the odor adjustment box 105 and the gas discharge outlet, and the third gas concentration sensor 111 is used to detect whether the concentration of the discharged gas meets the standards.

[0052] The second gas concentration sensor 109 is used to detect the concentration of the treated VOC waste gas. When the concentration of the detected VOC waste gas is higher than the standard value of the VOC waste gas concentration after a series of treatments on the VOC waste gas, the operator can adjust the ultraviolet energy emitted by the electrodeless ultraviolet lamp 11 and the microwave energy of the microwave source 1 through the control of the microwave treatment device 103 to increase the reaction rate of the VOC waste gas and enhance the waste gas treatment effect.

[0053] Combined with the embodiments of the present invention, the small air volume VOC waste gas treatment system further includes a control cabinet, which is used to control the electrical equipment of the small air volume VOC waste gas treatment system and is electrically connected to the variable frequency make-up air blower 108, the microwave treatment device 103, the variable frequency centrifugal fan 104, the first gas concentration sensor 110, the second gas concentration sensor 109 and the third gas concentration sensor 111.

[0054] Combined with the embodiments of the present invention, the waste gas inlet, the first flame arrester 106, the gas mixing chamber 101, the second flame arrester 107, the glass rotameter 102, the microwave treatment device 103, the variable frequency centrifugal fan 104, the odor adjustment box 105 and the gas discharge outlet are connected by pipelines. Among them, the inlet and outlet of the microwave treatment device 103 are soft-connected.

[0055] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0056] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0057] In the present invention, unless otherwise clearly defined or limited, terms such as "installed", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] In the present invention, unless otherwise clearly defined or limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower horizontal height than the second feature.

[0059] In the description of the present invention, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In the present invention, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine the different embodiments or examples described in the present invention and the features of different embodiments or examples.

[0060] Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A small air volume VOC waste gas treatment system, characterized in that, Including: A first flame arrester (106), a gas mixing chamber (101), a second flame arrester (107), a glass rotameter (102), a microwave treatment device (103), a variable-frequency centrifugal fan (104), an odor adjustment box (105) and a gas discharge outlet, which are sequentially connected after the waste gas inlet; It further includes a variable-frequency make-up air fan (108), and the variable-frequency make-up air fan (108) is connected to the gas mixing chamber (101) for diluting the high-concentration VOC waste gas in the gas mixing chamber (101); The microwave treatment device (103) is used for decomposing the pollution components in the VOC waste gas.

2. The small air volume VOC waste gas treatment system according to claim 1, wherein The microwave treatment device (103) at least includes: an electrodeless ultraviolet lamp (11), a microwave source (1), a filter chamber (7) and an electrostatic dust removal module (8); the electrodeless ultraviolet lamp (11), the microwave source (1) and the electrostatic dust removal module (8) are arranged between the inlet (4) and the outlet (5) of the microwave treatment device (103); the filter chamber (7) is connected to the inlet (4) of the microwave treatment device (103); wherein, the number of the electrodeless ultraviolet lamps (11) is at least 2, and the number of the microwave sources (1) is at least 3.

3. The small air volume VOC waste gas treatment system according to claim 2, wherein The filter chamber (7) includes a filter and a uniform air plate; the filter is used for filtering large particles in the VOC waste gas, and the uniform air plate is used for making the VOC waste gas flow evenly.

4. The small-air-volume VOC waste gas treatment system according to claim 2, wherein, A metal mesh (10) is arranged at the outlet of the microwave treatment device (103).

5. The small air volume VOC waste gas treatment system according to claim 4, characterized in that, The metal mesh (10) is made of 304 stainless steel.

6. The small-air-volume VOC waste gas treatment system according to claim 2, characterized in that, The electrodeless ultraviolet lamp (11) is an electrodeless ultraviolet lamp with a wavelength of 185nm.

7. The small air volume VOC waste gas treatment system according to claim 2, characterized in that, In the same time period, only two of the microwave sources (1) are working.

8. The small-air-volume VOC waste gas treatment system according to claim 1, characterized in that, It further includes: A control cabinet; the control cabinet is used for controlling the electrical equipment of the small-air-volume VOC waste gas treatment system.

9. The small-air-volume VOC waste gas treatment system according to claim 1, characterized in that, It further includes: A first gas concentration sensor (110), a second gas concentration sensor (109) and a third gas concentration sensor (111); The first gas concentration sensor (110) is arranged between the gas mixing chamber (101) and the second flame arrester (107); the second gas concentration sensor (109) is arranged between the variable-frequency centrifugal fan (104) and the odor adjustment box (105); the third gas concentration sensor (111) is arranged after the odor adjustment box (105).

10. The small air volume VOC waste gas treatment system according to claim 1, characterized in that, An ozone removal catalyst is arranged in the odor adjustment box (105).

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