A device for removing VOCs

Abstract

The application provides a device for removing VOCs, comprising a box, a rotating wheel and a rotating assembly. The rotating wheel is arranged in the box and is divided into a plurality of geometrically identical fan-shaped units along the circumference of the rotating wheel. The boundary line between adjacent fan-shaped units is a radial straight line passing through the center of the rotating wheel. Each fan-shaped unit comprises a fan-shaped mounting groove. Each mounting groove is provided with a molecular sieve assembly. One end of the molecular sieve assembly close to the center of the rotating wheel is rotatably connected to one end of the mounting groove close to the center of the rotating wheel. The molecular sieve assembly is used for adsorbing volatile organic compounds. A rotating assembly is arranged corresponding to each molecular sieve assembly. When one side of the molecular sieve assembly adsorbs VOCs to saturation, the rotating assembly is used to rotate the molecular sieve assembly, exchange the orientations of the two sides of the molecular sieve assembly, make the originally unsaturated side rotate to the waste gas side to continue adsorbing VOCs, and make the saturated side temporarily separate from the waste gas adsorption environment. In this way, the unsaturated part of the molecular sieve assembly can be fully utilized to continue waste gas treatment, and the utilization rate of the molecular sieve assembly is significantly improved.

Description

Technical Field

[0001] This invention relates to the field of waste gas treatment technology, and more specifically to a device for removing VOCs. Background Technology

[0002] With rapid industrialization and urbanization, emissions of volatile organic compounds (VOCs) are constantly increasing, causing serious pollution to the atmospheric environment. Many compounds in VOCs are toxic, irritating, teratogenic, and carcinogenic; therefore, effectively reducing VOC emissions has become an important issue in environmental protection. Among VOCs treatment technologies, zeolite molecular sieve rotary adsorption and concentration technology has become one of the mainstream solutions due to its high efficiency and stability.

[0003] Zeolite molecular sieve rotors are highly efficient VOCs treatment devices, operating on a continuous adsorption-desorption-cooling process. The rotor consists of an adsorption zone, a desorption zone, and a cooling zone, with rotation enabling the recycling of each zone. In the adsorption zone, VOCs in the exhaust gas are adsorbed by the zeolite molecular sieve, and the purified gas is directly emitted. Subsequently, the rotor enters the desorption zone, where, under the action of high-temperature hot air, the adsorbed VOCs are desorbed and concentrated. Finally, the gas is cooled to room temperature in the cooling zone, preparing it for the next adsorption cycle.

[0004] Zeolite molecular sieve rotors have the following advantages: First, their hydrophobicity and selective adsorption capacity enable them to efficiently remove VOCs from waste gas; second, the rotor structure is compact and the modular design facilitates installation and maintenance; third, zeolite molecular sieves can be reused through regeneration, reducing operating costs.

[0005] However, during the adsorption of VOCs in waste gas by molecular sieves, the molecular sieves closer to the waste gas side will reach saturation earlier. The molecular sieves that saturate earlier will hinder the adsorption of the unsaturated molecular sieves on the other side, affecting the overall utilization rate of the molecular sieves and failing to fully utilize their adsorption performance. Summary of the Invention

[0006] In view of the defects and shortcomings of the prior art, this application provides a device for removing VOCs to solve the problem that the overall utilization rate of molecular sieves is low and the adsorption performance of molecular sieves cannot be fully utilized in the prior art.

[0007] To achieve the above and other related objectives, this application provides an apparatus for removing VOCs, comprising:

[0008] Box;

[0009] A rotating wheel, disposed within the housing, is divided into multiple geometrically congruent sector units along its circumference. The boundary line between adjacent sector units is a radial straight line passing through the center of the rotating wheel. Each sector unit includes a sector-shaped mounting groove, and each mounting groove is provided with a molecular sieve assembly. The end of the molecular sieve assembly near the center of the rotating wheel is rotatably connected to the end of the mounting groove near the center of the rotating wheel. The molecular sieve assembly is used to adsorb volatile organic compounds.

[0010] A rotating assembly includes a gear ring, multiple gears meshing with the gear ring, at least one first drive mechanism, and multiple rotating shafts. The gear ring is fixedly disposed on the outer periphery of the rotating wheel along its circumference. The number of gears and rotating shafts corresponds to the number of mounting slots. The first drive mechanism is fixedly disposed outside the rotating wheel. The drive end of the first drive mechanism is fixedly connected to one of the gears. One end of the rotating shaft is fixedly connected to the gear, and the other end of the rotating shaft passes through the mounting slot and is fixedly connected to the end of the molecular sieve assembly away from the center of the rotating wheel. Alternatively, the rotating assembly includes multiple first drive mechanisms, multiple gears, and multiple rotating shafts. The number of first drive mechanisms, gears, and rotating shafts corresponds to the number of mounting slots. The first drive mechanism is fixedly disposed outside the rotating wheel. The drive end of the first drive mechanism is fixedly connected to the gear. One end of the rotating shaft is fixedly connected to the gear, and the other end of the rotating shaft passes through the mounting slot and is fixedly connected to the end of the molecular sieve assembly away from the center of the rotating wheel.

[0011] In one embodiment, the sector-shaped unit further includes a rotating groove, which is disposed adjacent to the mounting groove and close to the center of the rotating wheel;

[0012] The molecular sieve assembly includes a frame and a molecular sieve unit. The end of the frame away from the center of the rotating wheel is fixedly connected to the rotating shaft. A rotating ring is fixedly provided at the end of the frame near the rotating groove. The rotating ring is located in the rotating groove and is adapted to the rotating groove. The molecular sieve unit is disposed in the frame and is detachably connected to the frame.

[0013] In one embodiment, the molecular sieve unit includes a first molecular sieve unit and a second molecular sieve unit; the first molecular sieve unit and the second molecular sieve unit are sequentially arranged in the frame from the outer edge of the rotor to the center of the rotor;

[0014] A lifting groove is provided inside the frame near the rotating groove;

[0015] The first molecular sieve unit is detachably connected to the frame via a screw, the second molecular sieve unit is detachably connected to the frame via a pusher assembly, and the first molecular sieve unit and the second molecular sieve unit are connected via an elastic element;

[0016] The pushing assembly is located within the lifting groove. The pushing assembly includes a first wedge block, a second wedge block, a second driving mechanism, and a locking rod. The driving end of the second driving mechanism is fixedly connected to the first wedge block, and the second wedge block is fixedly connected to the locking rod. The inclined surface of the second wedge block abuts against the inclined surface of the first wedge block. The second driving mechanism drives the first wedge block to press the second wedge block, causing the second wedge block to rise. The driving direction of the second driving mechanism is perpendicular to the rising direction of the second wedge block. A first connecting rod is provided at one end of the second molecular sieve unit near the center of the rotor. The end of the locking rod away from the second wedge block is detachably connected to the first connecting rod.

[0017] In one embodiment, a locking groove is provided at the end of the first connecting rod near the locking rod; an electromagnetic lock is provided at the end of the locking rod away from the second wedge block, and the lock cylinder of the electromagnetic lock is adapted to the locking groove.

[0018] In one embodiment, the first molecular sieve unit includes a first frame and a first elastic support plate disposed within the first frame. The first elastic support plate is disposed close to the second molecular sieve unit, and both ends of the first elastic support plate are fixedly connected to the first frame.

[0019] The second molecular sieve unit includes a second frame and a second elastic support plate disposed within the second frame. The second elastic support plate is disposed away from the first molecular sieve unit, and both ends of the second elastic support plate are fixedly connected to the second frame.

[0020] The second elastic support plate has the first connecting rod disposed on the surface away from the first molecular sieve unit, and the second frame has a through hole at the end away from the first frame. The end of the first connecting rod away from the second elastic support plate can pass through the through hole.

[0021] A second connecting rod is fixedly disposed on the surface of the first elastic support plate near the second frame, and the second connecting rod passes through the first frame and is fixedly connected to one end of the second frame near the first frame;

[0022] A protective ring is provided at the edge of the first frame and the second frame that are close to each other.

[0023] In one embodiment, ZSM-5 modified molecular sieve blocks are provided between the interior of the first frame and the first elastic support plate, and between the interior of the second frame and the second elastic support plate.

[0024] As one embodiment, the preparation of the ZSM-5 modified molecular sieve block includes the following steps:

[0025] The modified ZSM-5 molecular sieve powder was ground and mixed with inorganic binder and inorganic fiber to obtain a mixed powder.

[0026] Organic plasticizers and pore-forming agents are added to water and mixed to form a uniform gel.

[0027] The mixed powder is mixed with the uniform gel to obtain a paste-like mixture;

[0028] The paste mixture is ultrasonically treated to eliminate air bubbles trapped in it, resulting in a homogeneous paste mixture.

[0029] The printing program is designed using AutoCAD software, and the uniform paste mixture is placed in a 3D printing device for 3D printing. Finally, the 3D printed product is subjected to low-temperature aging and shaping and high-temperature calcination to obtain ZSM-5 modified molecular sieve blocks.

[0030] As one embodiment, the preparation of the modified ZSM-5 molecular sieve powder includes the following steps:

[0031] Prepare sodium formate solutions with concentrations ranging from 0.3 mol / L to 0.7 mol / L;

[0032] Powdered ZSM-5 molecular sieve was immersed in the sodium formate solution, filtered under reduced pressure, and the resulting filter cake was dried at 120°C to constant weight and then crushed into powder to obtain modified ZSM-5 molecular sieve powder; the solid-liquid ratio (g:mL) of the ZSM-5 molecular sieve to the sodium formate solution was 1:4.

[0033] Preferably, the concentration of the sodium formate solution is between 0.3 mol / L and 0.5 mol / L.

[0034] In one embodiment, the interior of the housing is further provided with a first support frame and a second support frame, which are arranged opposite to each other. The rotating wheel is disposed between the first support frame and the second support frame and is rotatably connected to the first support frame and the second support frame.

[0035] The first support frame has a first cover on the top of the side away from the wheel, and the first cover includes a separately arranged air-gathering area and an air-guiding area;

[0036] The second support frame has a second cover on the top side away from the rotating wheel. The second cover includes a separate air collection area and an air supply area.

[0037] The gas gathering zone and the gas collecting zone are connected through the molecular sieve unit; the gas guiding zone and the gas supply zone are connected through the molecular sieve unit.

[0038] The enclosure is equipped with an exhaust gas inlet pipe, an exhaust gas branch pipe, a heating pipe, and a connecting pipe;

[0039] The inlet of the exhaust gas branch pipe is connected to the exhaust gas inlet pipe, and the outlet of the exhaust gas branch pipe is connected to the gas collection area.

[0040] The inlet of the heating pipe is connected to the outlet of the gas collection area, and the outlet of the heating pipe is connected to the inlet of the gas supply area. A heater and a fan are installed on the heating pipe.

[0041] The inlet of the connecting pipe is connected to the outlet of the air guiding zone.

[0042] In one embodiment, a third drive mechanism is provided on the second support frame, and the drive end of the third drive mechanism is fixedly connected to the rotating wheel;

[0043] Multiple filter screens are provided on the side of the rotating wheel near the first support frame. The filter screens are arranged in a circular array on the rotating wheel, and flow sensors are provided on the filter screens.

[0044] A sealing layer is provided between the molecular sieve assembly and the mounting groove.

[0045] As described above, the VOCs removal device of this application has the following beneficial effects:

[0046] The VOCs removal device of this application is equipped with a rotating component for each molecular sieve assembly. When one side of the molecular sieve assembly reaches saturation with VOCs, the rotating component rotates the assembly, changing the orientation of its two sides. The unsaturated side moves to the waste gas side to continue adsorbing VOCs, while the saturated side is temporarily removed from the waste gas adsorption environment. This fully utilizes the unsaturated portion of the molecular sieve assembly for waste gas treatment, significantly improving the utilization rate of the molecular sieve assembly. During adsorption, the swapped molecular sieve assembly balances the workload on both sides, avoiding the situation where premature saturation on one side hinders adsorption on the other side. This allows the molecular sieve assembly to work in a more balanced state, further improving its adsorption effect and better meeting the requirements for VOCs adsorption in waste gas treatment, ensuring that waste gas emissions comply with environmental standards. By rotating the two sides of the molecular sieve assembly, the overall service life of the molecular sieve assembly is effectively extended. Compared with traditional molecular sieve assembly replacement methods, this method reduces the frequency of molecular sieve assembly replacement, lowering the time and economic costs associated with replacement. It also helps reduce the potential pollution caused by discarded molecular sieves, resulting in good economic and environmental benefits. Attached Figure Description

[0047] Figure 1 The diagram shown is a structural schematic of the device for removing VOCs according to Embodiment 1 of the present invention.

[0048] Figure 2 The diagram shown is a structural schematic of the rotor in the VOCs removal device according to Embodiment 1 of the present invention.

[0049] Figure 3 This is a schematic diagram of the rotor in the VOCs removal device according to Embodiment 1 of the present invention from another perspective.

[0050] Figure 4 The diagram shown is a schematic diagram of one of the sector-shaped units of the rotor in the VOCs removal device according to Embodiment 1 of the present invention.

[0051] Figure 5 Displayed as Figure 4 Enlarged view of the structure of part A in the middle.

[0052] Figure 6 Displayed as Figure 4 Enlarged view of the structure of section B in the middle.

[0053] Figure 7 The diagram shown is a structural schematic of the rotating wheel, the first support frame, and the second support frame in the VOCs removal device according to Embodiment 2 of the present invention.

[0054] Figure 8This is a schematic diagram of the rotating wheel, the first support frame, and the second support frame in the VOCs removal device according to Embodiment 2 of the present invention from another perspective.

[0055] Figure 9 The diagram shown is a structural schematic diagram from one perspective of the VOCs removal device according to Embodiment 2 of the present invention.

[0056] Figure 10 This is a schematic diagram showing another perspective of the VOCs removal device according to Embodiment 2 of the present invention.

[0057] Figure 11 The diagram shows the N2 adsorption-desorption isotherms of ZSM-5 molecular sieve before and after alkali treatment in Example 3 of the present invention.

[0058] Figure 12 The diagram shown is a schematic diagram of the pore size distribution of the ZSM-5 molecular sieve before and after alkali treatment in Example 3 of the present invention.

[0059] Figure 13 The image shows the infrared spectra of ZSM-5 molecular sieve before and after modification in Example 3 of this invention.

[0060] Figure 14 The figures shown are the adsorption curves and error bars of ZSM-5 molecular sieves for VOCs before and after modification in Example 3 of this invention.

[0061] Figure 15 Displayed as Figure 14 Adsorption curves and error bar graphs of ZSM-5 molecular sieve for VOCs before and after modification are shown in the continued figures.

[0062] Figure 16 The diagram shown is a schematic diagram of the thermal desorption of ZSM-5 molecular sieve onto a high-solidity epoxy paint 380 solvent system, which is an adsorbate, according to Embodiment 3 of the present invention.

[0063] Figure 17 The diagram shown is a schematic diagram of the thermal desorption of ZSM-5 molecular sieve onto a general epoxy paint 510 solvent system, which is an adsorbate, according to Embodiment 3 of the present invention.

[0064] Figure 18 The diagram shown is a schematic diagram of the thermal desorption of ZSM-5 molecular sieve onto an adsorbate system of acrylic silane low-resistivity self-smoothing antifouling paint (P) solvent system, which is an embodiment of the present invention.

[0065] Figure 19 The diagram shown is a schematic diagram of the thermal desorption of the ZSM-5 molecular sieve onto a xylene solvent system, as described in Example 3 of this invention.

[0066] Figure 20 The diagram shown is a schematic diagram of the thermal desorption of ZSM-5 molecular sieve onto an ethylbenzene solvent system, as described in Example 3 of this invention.

[0067] Component Symbol Explanation

[0068] 10, Box body; 20, Rotary wheel; 30, Molecular sieve assembly; 40, Pushing assembly; 50, First support frame; 60, Second support frame; 70, First cover; 80, Second cover; 110, Exhaust gas inlet pipe; 111, Exhaust gas branch pipe; 120, Heating pipe; 130, Connecting pipe; 201, Mounting groove; 202, Rotating groove; 203, Filter screen plate; 204, Sealing layer; 210, Rotating assembly; 211, Gear ring; 212, First drive mechanism; 213, Gear; 214, Rotating shaft; 310, Frame; 311, Rotating ring; 312, Lifting groove; 3 20, Molecular sieve unit; 321, First molecular sieve unit; 322, Second molecular sieve unit; 323, Elastic element; 324, Protective ring; 410, Second drive mechanism; 420, First wedge block; 430, Second wedge block; 440, Locking rod; 610, Third drive mechanism; 710, Gas gathering zone; 720, Gas guiding zone; 810, Gas collecting zone; 820, Gas supply zone; 3211, First elastic support plate; 3212, Second connecting rod; 3213, First frame; 3221, First connecting rod; 3222, Second elastic support plate; 3223, Second frame. Detailed Implementation

[0069] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0070] Please see Figures 1 to 20 It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the number, shape and size of the components in the actual embodiment. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0071] Example 1

[0072] This embodiment provides a device for removing VOCs, such as... Figures 1 to 3 As shown, the VOCs removal device includes a housing 10, a rotor 20, a molecular sieve assembly 30, and a rotating assembly 210.

[0073] like Figure 1 As shown, the rotating wheel 20 is disposed inside the housing 10. Figures 1 to 3As shown, along the circumference of the rotating wheel 20, the interior of the rotating wheel 20 is divided into multiple geometrically congruent sector-shaped units, and the boundary line between adjacent sector-shaped units is a radial straight line passing through the center of the rotating wheel 20. Each sector-shaped unit includes a sector-shaped mounting groove 201, and each mounting groove 201 contains a molecular sieve assembly 30. The end of the molecular sieve assembly 30 near the center of the rotating wheel 20 is rotatably connected to the end of the mounting groove 201 near the center of the rotating wheel 20. The molecular sieve assembly 30 is used to adsorb volatile organic compounds (VOCs).

[0074] As one implementation method, such as Figure 2 and Figure 4 As shown, the rotating assembly 210 includes a gear ring 211, a plurality of gears 213 meshing with the gear ring 211, at least one first drive mechanism 212, and a plurality of rotating shafts 214. The gear ring 211 is fixedly disposed on the rotating wheel 20 around the outer periphery of the rotating wheel 20; the number of gears 213 and rotating shafts 214 corresponds to the number of mounting slots 201, or in other words, to the number of molecular sieve assemblies 30. The first drive mechanism 212 is fixedly disposed on the outside of the rotating wheel 20, close to the gear ring 211. The drive end of the first drive mechanism 212 is fixedly connected to one of the gears 213, and the remaining gears 213 are rotatably connected to the outside of the rotating wheel 20; if the number of first drive mechanisms 212 is multiple but not as many as the number of gears 213, the first drive mechanisms 212 can be spaced out, or can be continuously disposed, or can be disposed in a series of consecutive arrangements followed by spaced-out arrangements. One end of the rotating shaft 214 is fixedly connected to the gear 213, and the other end of the rotating shaft 214 passes through the outer edge of the rotating wheel 20 and extends into the mounting groove 201, and is fixedly connected to the end of the molecular sieve assembly 30 away from the center of the rotating wheel 20.

[0075] As one implementation method, such as Figure 3 As shown, the rotating assembly 210 includes multiple gears 213, multiple first drive mechanisms 212, and multiple rotating shafts 214. The number of gears 213, first drive mechanisms 212, and rotating shafts 214 are equal, and one gear 213, one first drive mechanism 212, and one rotating shaft 214 form a group, corresponding to one mounting groove 201. The first drive mechanism 212 is fixedly disposed on the outside of the rotating wheel 20. The drive end of the first drive mechanism 212 rotates and is fixedly connected to the gear 213. The surface of the gear 213 away from the first drive mechanism 212 is fixedly connected to one end of the rotating shaft 214. The other end of the rotating shaft 214 passes through the outer edge of the rotating wheel 20 and extends into the mounting groove 201, and is fixedly connected to the end of the molecular sieve assembly 30 away from the center of the rotating wheel 20.

[0076] The VOCs removal device provided in this embodiment, by setting a rotating component 210 and rotatably connecting the molecular sieve component 30 and the mounting groove 201, allows the molecular sieve component 30 to rotate when one side of the molecular sieve component 30 reaches saturation with VOCs, thereby changing the orientation of the two sides. This improves the utilization rate of the molecular sieve component 30, increases the adsorption efficiency of VOCs in the exhaust gas, and balances the workload of both sides of the molecular sieve component 30 by rotating and using the two sides alternately, extending the overall service life of the molecular sieve component 30, reducing the replacement frequency of the molecular sieve component 30, and lowering the cost of exhaust gas.

[0077] In an optional embodiment, the first drive mechanism 212 may be a rotary motor.

[0078] In optional embodiments, such as Figure 4 and Figure 5 As shown, the sector-shaped unit also includes a rotating groove 202, which is disposed adjacent to the mounting groove 201 and near the center of the rotating wheel 20. Both the mounting groove 201 and the rotating groove 202 are grooves formed on the rotating wheel 20. In one specific embodiment, the projection of the rotating groove 200 onto the surface of the mounting groove 201 near the center of the rotating wheel 20 is located at the center of that surface.

[0079] In an optional embodiment, VOCs concentration sensors are installed on both the side of the molecular sieve assembly 30 closest to the exhaust gas inlet and the side furthest from the exhaust gas inlet. The concentration distribution on both sides of the molecular sieve assembly 30 can be detected by the VOCs concentration sensors.

[0080] During use, the concentration distribution of VOCs on both sides of the molecular sieve assembly 30 is detected by a VOCs concentration sensor. When the VOCs concentration sensor on the side of the molecular sieve assembly 30 near the exhaust gas inlet detects that the VOCs concentration has reached the set threshold, it indicates that the molecular sieve assembly 30 near the exhaust gas inlet has reached saturation in adsorbing VOCs. At this time, the continued introduction of exhaust gas into the housing 10 and the emission of gas from the housing 10 are stopped. The first drive mechanism 212 is started to drive the gear 213 to rotate. Under the meshing of the gear 213 and the gear ring 211, the gear ring 211 drives the other gears 213 to rotate (or, in the case where the gear ring 211 is not set and multiple first drive mechanisms 212 are set, the first drive mechanism 212 is started and the gear 213 is driven to rotate), thus completing the front and rear swapping of multiple sets of molecular sieve assemblies 30. By swapping the front and back of the molecular sieve assembly 30, the utilization rate of the molecular sieve assembly 30 can be improved, and the adsorption efficiency of VOCs in the exhaust gas can be increased. This avoids the molecular sieve assembly 30 becoming saturated on one side and hindering the adsorption on the other side. By swapping the two sides of the molecular sieve assembly 30 for alternating use, the workload on both sides of the molecular sieve assembly 30 can be balanced, the overall service life of the molecular sieve assembly 30 can be extended, and the replacement frequency of the molecular sieve assembly 30 can be reduced.

[0081] like Figure 2 As shown, the molecular sieve assembly 30 includes a frame 310 and molecular sieve units 320, with the frame 310 disposed within the mounting groove 201. Specifically, as... Figure 4 and Figure 5 As shown, the end of the frame 310 furthest from the center of the rotating wheel 20 is fixedly connected to the rotating shaft 214. A rotating ring 311 is fixedly installed at the end of the frame 310 closest to the rotating groove 202. The rotating ring 311 is located inside the rotating groove 202 and is adapted to fit the groove. This allows for the rotational connection between the frame 310 and the rotating groove 202, and enables the frame 310 to rotate when the rotating assembly 210 rotates. The molecular sieve unit 320 is disposed inside the frame 310 and is detachably connected to the frame 310. This allows for easy replacement of only the molecular sieve unit 320 when it needs to be replaced.

[0082] In optional embodiments, such as Figure 2 As shown, the molecular sieve unit 320 includes a first molecular sieve unit 321 and a second molecular sieve unit 322. From the outer edge of the rotating wheel 20 to the center of the rotating wheel 20, the first molecular sieve unit 321 and the second molecular sieve unit 322 are arranged sequentially in the frame 310, that is, the first molecular sieve unit 321 is arranged away from the center of the rotating wheel 20, and the second molecular sieve unit 322 is arranged close to the center of the rotating wheel 20.

[0083] like Figure 4 and Figure 6As shown, the first molecular sieve unit 321 and the second molecular sieve unit 322 are connected by an elastic element 323. The first molecular sieve unit 321 is detachably connected to the frame 310 by a screw, and the second molecular sieve unit 322 is detachably connected to the frame 310 by a pushing assembly 40. Optionally, the elastic element 323 may be, for example, a spring. In one specific embodiment, the elastic element 323 is symmetrically arranged between the first molecular sieve unit 321 and the second molecular sieve unit 322. Specifically, a threaded hole is provided on the side of the frame 310 away from the center of the rotating wheel 20, and the first molecular sieve unit 321 is installed and fixed by connecting the screw to the threaded hole on the frame 310.

[0084] like Figure 4 and Figure 5 As shown, a lifting groove 312 is provided inside the frame 310 near the rotating groove 202, and the pushing assembly 40 is located within the lifting groove 312. The pushing assembly 40 includes a second driving mechanism 410, a first wedge block 420, a second wedge block 430, and a locking rod 440. Both the first wedge block 420 and the second wedge block 430 have an inclined surface, and the slopes of their inclined surfaces are the same. In one specific embodiment, the top inclined surface of the first wedge block 420 engages with the bottom inclined surface of the second wedge block 430. The driving end of the second driving mechanism 410 is fixedly connected to one surface of the first wedge block 420, and one surface of the second wedge block 430 is fixedly connected to the locking rod 440. The driving direction of the driving end of the second driving mechanism 410 is perpendicular to the locking rod 440, the inclined surface of the first wedge block 420 abuts against the inclined surface of the second wedge block 430, and the driving direction of the second driving mechanism 410 is perpendicular to the rising direction of the second wedge block 430. The second molecular sieve unit 322 has a first connecting rod 3221 at one end near the center of the rotor 20, and the locking rod 440 at one end away from the second wedge block 430 is detachably connected to the end of the first connecting rod 3221 near the center of the rotor 20. In one specific embodiment, the second driving mechanism 410 may be, for example, a cylinder, and the telescopic end of the cylinder is fixedly connected to the first wedge block 420.

[0085] The VOCs removal device provided in this embodiment includes the following steps for installing the molecular sieve unit 320 on the frame 310: First, the first molecular sieve unit 321 is installed and fixed to the frame 310 by connecting and fixing with a screw and a threaded hole; second, pressure is applied to the second molecular sieve unit 322, causing it to move closer to the first molecular sieve unit 321, causing the elastic element 323 between the two to contract, and simultaneously causing the first connecting rod 3221 to correspond with the locking rod 440; third, by removing the pressure applied to the second molecular sieve unit 322, the end of the first connecting rod 3221 near the locking rod 440 passes through the second molecular sieve unit 322 and connects and locks with the locking rod 440; finally, the installation of the multiple molecular sieve units 320 on the frame 310 is completed in the above manner.

[0086] When the molecular sieve unit 320 reaches its preset service time and needs to be replaced: the second drive mechanism 410 drives the first wedge block 420 forward, and the top inclined surface of the first wedge block 420 cooperates with the bottom inclined surface of the second wedge block 430 to compress the second molecular sieve unit 322 and the first molecular sieve unit 321. At the same time, the locking rod 440 pushes the first connecting rod 3221 into the second molecular sieve unit 322 and releases the locking relationship between the two. The screw of the first molecular sieve unit 321 is unscrewed from the threaded hole of the frame 310 to complete the removal of the old molecular sieve unit 320. Then, the new molecular sieve unit 320 is installed on the frame 310 according to the above steps of installing the molecular sieve unit 320 on the frame 310.

[0087] In an optional embodiment, the first connecting rod 3221 is provided with a locking groove at the end near the locking rod 440, and the locking rod 440 is provided with an electromagnetic lock at the end away from the second wedge block 430, with the lock cylinder of the electromagnetic lock being adapted to the locking groove.

[0088] Example 2

[0089] This embodiment also provides a device for removing VOCs, such as... Figures 7 to 10 As shown, the similarities between this VOCs removal device and Embodiment 1 will not be repeated here. The differences from Embodiment 1 are as follows:

[0090] like Figure 1 , Figure 7 and Figure 8 As shown, the interior of the housing 10 is also provided with a first support frame 50 and a second support frame 60. The first support frame 50 and the second support frame 60 are arranged opposite to each other with a gap between them. The rotating wheel 20 is disposed in the gap and is rotatably connected to the first support frame 50 and the second support frame 60.

[0091] like Figure 7 As shown, a first cover 70 is provided on the top of the side of the first support frame 50 away from the rotating wheel 20. The first cover 70 includes a separately configured air-gathering area 710 and an air-guiding area 720. The top of the first cover 70 is fixedly connected to the top surface inside the housing 10. A partition is provided inside the first cover 70 to divide it into the air-gathering area 710 and the air-guiding area 720.

[0092] like Figure 8 As shown, a second cover 80 is provided on the top of the side of the second support frame 60 away from the rotating wheel 20. The second cover 80 includes a separately configured air collection area 810 and an air supply area 820. The top of the second cover 80 is fixedly connected to the top surface inside the housing 10. A partition is provided inside the second cover 80 to divide it into the air collection area 810 and the air supply area 820.

[0093] The gas gathering zone 710 is connected to the gas collecting zone 810 through the molecular sieve unit 320 on the rotor 20. The gas guiding zone 720 is connected to the gas supply zone 820 through the molecular sieve unit 320 on the rotor 20.

[0094] like Figure 9 and Figure 10 As shown, the exterior of the housing 10 is equipped with an exhaust gas inlet pipe 110, an exhaust gas branch pipe 111, a heating pipe 120, and a connecting pipe 130. The outlet of the exhaust gas inlet pipe 110 is connected to the interior of the housing 10. A cooling fan is installed on the exhaust gas inlet pipe 110 to cool the airflow inside the exhaust gas inlet pipe 110, and part of the cooled airflow flows to the exhaust gas branch pipe 111. The exhaust gas branch pipe 111 is connected to the exhaust gas inlet pipe 110, that is, the exhaust gas branch pipe 111 is a branch of the exhaust gas inlet pipe 110. The outlet of the exhaust gas branch pipe 111 is connected to the gas collection zone 710, and the exhaust gas branch pipe 111 is used to cool the desorbed rotor 20. The inlet of heating pipe 120 is connected to the outlet of gas collection zone 810, and the outlet of heating pipe 120 is connected to the inlet of gas supply zone 820. A heater and a fan are installed on heating pipe 120, with the fan positioned close to gas supply zone 820. The fan continuously delivers the air heated by the heater to gas supply zone 820. The inlet of connecting pipe 130 is connected to the outlet of gas guiding zone 720, and the outlet of connecting pipe 130 is connected to subsequent processing equipment. The heated gas in heating pipe 120 enters gas supply zone 820, then passes through the molecular sieve unit 320 of rotor 20, enters gas guiding zone 720, and is finally discharged outwards through connecting pipe 130.

[0095] In this embodiment, during the use of the VOCs removal device, exhaust gas enters the housing 10 through the exhaust gas inlet pipe 110 and the exhaust gas branch pipe 111. The exhaust gas entering the housing 10 through the exhaust gas inlet pipe 110 is directly blown onto the rotor 20, where the molecular sieve assembly 30 mounted on the rotor 20 adsorbs the VOCs in the exhaust gas. The exhaust gas entering the housing 10 through the exhaust gas branch pipe 111 flows into the gas collection zone 710, and then flows from the gas collection zone 710 through the molecular sieve assembly 30 on the rotor 20 to the gas collection zone 8. 10. Gas flowing out of the gas collection zone 810 enters the heating pipe 120. After being heated by the heater on the heating pipe 120, the gas is transported to the gas supply zone 820 by the fan on the heating pipe 120. When the gas flowing out of the gas supply zone 820 passes through the molecular sieve assembly 30 on the rotor 20, the VOCs gas on the molecular sieve assembly 30 is desorbed and flows together into the guide gas zone 720. Then, it is discharged outward through the connecting pipe 130 connected to the guide gas zone 720 to the next processing step. The above process is repeated. During this process, the rotor 20 does not rotate.

[0096] Subsequently, the rotation of the rotor 20 causes the molecular sieve assembly 30, after hot air desorption, to move with the rotor 20 to the position corresponding to the gas collection zone 710. The low-temperature exhaust gas, cooled by the cooling fan on the exhaust gas branch pipe 111, enters the gas collection zone 710 and then flows from the gas collection zone 710 through the molecular sieve assembly 30 on the rotor 20 into the gas collection zone 810. During this process, the low-temperature exhaust gas rapidly cools the molecular sieve assembly 30, restoring its ability to continue adsorbing VOCs from the exhaust gas. As the rotor 20 rotates, the above process is repeated, allowing the molecular sieve assembly 30 in the rotor 20 to sequentially complete the adsorption of VOCs from the exhaust gas, the desorption of VOCs, and the cooling of the rotor 20 and the molecular sieve assembly 30.

[0097] In optional embodiments, such as Figure 7 and Figure 8 As shown, a third drive mechanism 610 is provided on the second support frame 60, and the drive end of the third drive mechanism 610 is fixedly connected to the rotating wheel 20. In one specific embodiment, the third drive mechanism 610 may be, for example, a drive motor, and the rotating shaft of the drive motor is fixedly connected to the center of the rotating wheel 20. The drive motor drives the rotating wheel 20 to rotate, so that the rotating wheel 20 sequentially performs adsorption, desorption and cooling.

[0098] In optional embodiments, such as Figure 7 As shown, a plurality of filter screens 203 are provided on the side of the rotating wheel 20 near the first support frame 50. The filter screens 203 are arranged in a ring array on the rotating wheel 20, and a flow sensor is provided on the filter screens 203. The filter screens 203 have a plurality of filter holes, which block fine particulate impurities.

[0099] In an optional embodiment, a sealing layer 204 is provided between the molecular sieve assembly 30 and the mounting groove 201.

[0100] In optional embodiments, such as Figures 4 to 6 As shown, the first molecular sieve unit 321 includes a first frame 3213 and a first elastic support plate 3211 disposed within the first frame 3213. The first elastic support plate 3211 is disposed close to the second molecular sieve unit 322, and both ends of the first elastic support plate 3211 are fixedly connected to the first frame 3213.

[0101] The second molecular sieve unit 322 includes a second frame 3223 and a second elastic support plate 3222 disposed within the second frame 3223. The second elastic support plate 3222 is disposed away from the first molecular sieve unit 321, and both ends of the second elastic support plate 3222 are fixedly connected to the second frame 3223.

[0102] The second elastic support plate 3222 has a first connecting rod 3221 on its surface away from the first molecular sieve unit 321. The second frame 3223 has a through hole at one end away from the first frame 3213. The first connecting rod 3221 can be detachably connected to the locking rod 440 through the through hole at one end away from the second elastic support plate 3222.

[0103] A second connecting rod 3212 is fixedly disposed on the surface of the first elastic support plate 3211 near the second frame 3223. The second connecting rod 3212 passes through the first frame 3213 and is fixedly connected to one end of the second frame 3223 near the first frame 3213. In one specific embodiment, the second connecting rod 3212 is located at the center of the surface of the first elastic support plate 3211 to which it is connected, and also at the middle of the two elastic elements 323.

[0104] A protective ring 324 is provided at the edge of the first frame 3213 and the second frame 3223 that are close to each other. The protective ring 324 is a sealing protective ring to form a seal between the first molecular sieve unit 321 and the second molecular sieve unit 322.

[0105] A ZSM-5 modified molecular sieve block is disposed inside the first frame 3213 located above the first elastic support plate 3211, and a ZSM-5 modified molecular sieve block is disposed inside the second frame 3223 located above the second elastic support plate 3222.

[0106] In the prior art, after the molecular sieve assembly 30 completes the adsorption of VOCs in the exhaust gas, the molecular sieves in the assembly 30 are densely packed. When heated air blows through the molecular sieve assembly 30, the heating rate of the hot air is slow, and it cannot efficiently contact the molecular sieves to desorb VOCs. The VOCs removal device provided in this embodiment can solve the above problems, specifically:

[0107] In use, after the first molecular sieve unit 321 is fixedly connected to the frame 310 by a screw, the elastic element 323 serves as the elastic support between the first molecular sieve unit 321 and the second molecular sieve unit 322. When the third drive mechanism 610 drives the rotating wheel 20 to rotate, causing the molecular sieve assembly 30 to desorb VOCs corresponding to the gas guiding zone 720 and the gas supply zone 820, the second drive mechanism 410 drives the first wedge block 420 to retract backward. The second wedge block 430, the second elastic support plate 3222, and the first elastic support plate 3211 simultaneously lose the supporting force of the first wedge block 420. When the second elastic support plate 3222 and the first elastic support plate 3211 are not supported by external force (i.e., in their initial form), they are in a state of... After losing the support of the first wedge block 420, the second elastic support plate 3222 and the first elastic support plate 3211 return to their downward arched shape. At this time, an active space for the ZSM-5 modified molecular sieve block will appear in the first molecular sieve unit 321 and the second molecular sieve unit 322. Based on this active space, during VOCs desorption, the third drive mechanism 610 repeatedly drives the first wedge block 420 to move back and forth. During this process, the first wedge block 420 uses its top inclined surface to interact with the second wedge block. The bottom inclined surface of block 430 engages with the locking rod 440 and the first connecting rod 3221, which repeatedly drive the middle part of the second elastic support plate 3222 to move up and down, creating a vibration effect. This causes the gap size between the ZSM-5 modified molecular sieve blocks inside the second molecular sieve unit 322 to change repeatedly under the vibration. At the same time, during this process, after the second elastic support plate 3222 compresses and compacts the ZSM-5 modified molecular sieve blocks inside the second molecular sieve unit 322, it will further drive the second molecular sieve unit... 322 moves towards the first molecular sieve unit 321, compressing the elastic element 323, causing the second connecting rod 3212 to drive the middle part of the first elastic support plate 3211 to arch upwards. This allows the third drive mechanism 610 to repeatedly drive the first wedge block 420 back and forth, while the second molecular sieve unit 322 and the first molecular sieve unit 321, under the vibration of the second elastic support plate 3222 and the first elastic support plate 3211 respectively, cause the gap size between the ZSM-5 modified molecular sieve blocks to change repeatedly. When the hot airflow passes through the molecular sieve assembly 30, the hot airflow utilizes the gaps between the ZSM-5 modified molecular sieve blocks to accelerate the overall heating efficiency of the ZSM-5 modified molecular sieve blocks, while simultaneously allowing VOCs within the ZSM-5 modified molecular sieve blocks to desorb and release more smoothly from the ZSM-5 modified molecular sieve blocks through the gaps between the molecular sieves.

[0108] With the cooperation of the first wedge block 420 and the second wedge block 430, the extension of the cylinder's telescopic end allows the top inclined surface of the first wedge block 420 and the bottom inclined surface of the second wedge block 430 to push the second elastic support plate 3222 upward, further reducing the gap between the ZSM-5 modified molecular sieve blocks in the second molecular sieve unit 322. Conversely, the contraction of the cylinder's telescopic end, combined with the elastic restoring force of the second elastic support plate 3222 and the first elastic support plate 3211 and the rebound force of the elastic element 323, increases the gap between the ZSM-5 modified molecular sieve blocks in the second molecular sieve unit 322 and the first molecular sieve unit 321, thereby improving the smoothness of airflow. The gap between the ZSM-5 modified molecular sieve blocks in the second molecular sieve unit 322 and the first molecular sieve unit 321 can be adjusted according to the concentration of VOCs in the exhaust gas delivered to the housing 10. As one specific implementation method, when the VOCs concentration in the exhaust gas is high, the gaps between the molecular sieves in the ZSM-5 modified molecular sieve block are reduced to improve the adsorption effect of VOCs in the exhaust gas; when the VOCs concentration in the exhaust gas is low, the gaps between the molecular sieves in the ZSM-5 modified molecular sieve block are increased to reduce energy consumption.

[0109] Furthermore, when the second molecular sieve unit 322 and the first molecular sieve unit 321 correspond to the positions of the gas accumulation zone 710 and the gas collection zone 810, by increasing the mutual gap between the ZSM-5 modified molecular sieve blocks in the second molecular sieve unit 322 and the first molecular sieve unit 321, the cooling rate of the ZSM-5 modified molecular sieve blocks in the second molecular sieve unit 322 and the first molecular sieve unit 321 is accelerated, so that the second molecular sieve unit 322 and the first molecular sieve unit 321 can quickly restore their adsorption capacity for VOCs in the exhaust gas.

[0110] Example 3

[0111] This embodiment provides a method for preparing modified ZSM-5 molecular sieve powder, including the following steps:

[0112] S10. Prepare a sodium formate solution with a concentration of 0.3 mol / L to 0.7 mol / L;

[0113] S20. Take powdered ZSM-5 molecular sieve, immerse it in the above sodium formate solution, filter under reduced pressure, dry the obtained filter cake at 120℃ to constant weight, and crush it into powder to obtain modified ZSM-5 molecular sieve powder. The solid-liquid ratio (g:mL) of ZSM-5 molecular sieve to sodium formate is 1:4.

[0114] In this embodiment, a sodium formate solution with moderate alkalinity was used to modify ZSM-5 molecular sieve, and the changes in specific surface area, pore size, and pore volume of ZSM-5 molecular sieve after alkali treatment were investigated.

[0115] Regarding the modification of ZSM-5 molecular sieves:

[0116] Using an electronic balance (OHAUS) (CP114, OHAUS Instruments (Shanghai) Co., Ltd.), weigh out 0.2039 g, 0.2726 g, 0.3419 g, 0.4075 g, and 0.4769 g of sodium formate (Sodium formate, AR, ≥99.5%, Anhui Zesheng Technology Co., Ltd.), respectively, to prepare sodium formate solutions of 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, and 0.7 mol / L, respectively. Weigh out 2.5 g of powdered ZSM-5 molecular sieve (Henan Woda Environmental Protection Materials Co., Ltd.) and immerse it in the sodium formate solutions of the above concentrations at a liquid-to-solid ratio (mL:g) of 4:1 for 3 hours. Filter under reduced pressure (using a circulating water multi-purpose vacuum pump, SH...). Z-D(Ⅲ), Shanghai Tianheng Instrument Co., Ltd.), the filter cake was dried to constant weight in a 120℃ oven (electric thermostatic drying oven, DHG-9030A, Shanghai Jinghong Experimental Equipment Co., Ltd.), crushed into powder for later use, and labeled as ZSM-5-3, ZSM-5-4, ZSM-5-5, ZSM-5-6, and ZSM-5-7 respectively, and the unmodified one was labeled as ZSM-5-0; after N2 physical adsorption and desorption experiments (specific surface area and pore size distribution tester, ASAP2020, Micromeritics), the final suitable modification concentration was determined; and the modified ZSM-5 molecular sieve at the appropriate concentration was detected by ATR-IR; the prepared sample was crushed into powder for later use.

[0117] As shown in Table 1, alkaline treatment with sodium formate solution can modify the S content of ZSM-5 molecular sieve. BET When the sodium formate concentration is 0.5 mol / L, S decreases. meso / S BET and S meso / S micro The value is the largest, S micro / S BET The smallest value indicates the best modification effect; at the same time, it was found that V total V micro S BET S micro The S value decreased due to alkaline treatment with sodium formate solution, but when the sodium formate concentration was 0.5 mol / L, the S value was lower. meso / S BET The increased proportion of [a certain percentage] leads to the conclusion that alkali treatment can generate mesopores, but it destroys the original microporous framework structure. Because the alkali treatment conditions are relatively mild, most of the Si removal from molecular sieves occurs on the surface. Here, "micro" is an abbreviation for micropore, and "meso" is an abbreviation for mesopore.

[0118] Table 1: Pore parameters of ZSM-5 molecular sieve before and after sodium formate solution treatment

[0119] ZSM-5-0 362.41 0.2270 284.24 0.1149 78.18 0.1122 ZSM-5-3 349.54 0.2143 265.69 0.1075 83.91 0.1068 ZSM-5-4 335.39 0.2091 276.26 0.1112 59.14 0.0979 ZSM-5-5 347.28 0.2014 263.33 0.1065 83.95 0.0949 ZSM-5-6 331.98 0.1780 287.08 0.1151 44.90 0.0629 ZSM-5-7 324.39 0.1960 259.19 0.10456 65.20 0.0914

[0120] N2 adsorption-desorption tests were performed on ZSM-5 molecular sieves before and after alkali treatment with sodium formate solution to investigate the effect of different alkali concentrations on the pores of ZSM-5 molecular sieves. The results are as follows: Figure 11 As shown, both the unmodified ZSM-5 molecular sieve and the ZSM-5 series molecular sieves treated with sodium formate solutions at concentrations of 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, and 0.6 mol / L exhibited type IV isotherms and all had H4 type hysteresis loops. The pore structure was irregular, and the hysteresis loop area fluctuated slightly with different alkali treatment concentrations. The specific surface area did not change significantly before and after modification. The ZSM-5 molecular sieves modified with 0.7 mol / L sodium formate solution all exhibited type IV isotherms, and the hysteresis loops disappeared. The originally formed mesopores further evolved into macropores under the action of alkali because the concentration of 0.7 mol / L sodium formate solution caused excessive etching of the molecular sieve structure.

[0121] The pore size distribution and corresponding pore volume accumulation of micropores and mesopores in the molecular sieve were fitted, and the results are as follows: Figure 12 As shown, by Figure 12 It can be seen that the ZSM-5 molecular sieve modified with 0.3 mol / L, 0.4 mol / L, and 0.5 mol / L sodium formate solutions showed a significant increase in pore volume in the 2 nm to 3 nm range compared to the unmodified sieve, indicating the formation of a large number of mesopores. However, the ZSM-5 molecular sieve modified with 0.6 mol / L and 0.7 mol / L sodium formate solutions did not show a significant increase in pore volume, possibly because the high alkali concentration caused further collapse of the formed mesopores.

[0122] Depend on Figure 13 It can be known that 550cm -1 The left and right sides are characteristic peaks of the five-membered ring, 800cm. -1 The left and right sides exhibit Si-O-Al symmetrical stretching vibration, 1100 cm⁻¹ -1 The left and right sides are skeletal vibrations. There is no significant change in the infrared peaks before and after modification. Modification only removes Si and does not significantly change the skeletal structure.

[0123] Regarding the determination of saturated adsorption capacity:

[0124] 5g of the modified ZSM-5 molecular sieve was immersed in a disposable plastic cup containing xylene and statically adsorbed at room temperature for 24h.

[0125] Place the sample on a windowsill and allow xylene to evaporate in a ventilated environment. Weigh the sample when it is noticeably dry and record the weight every 24 hours until a constant weight of m2 is achieved.

[0126] Two sets of parallel experiments were conducted to determine the saturated adsorption capacity of a mixture of high-strength epoxy paint 380 solvent system, general epoxy paint 510 solvent system, acrylic silane low-resistance self-smoothing antifouling paint (P) solvent system (JOTUN, in which the molar ratios of xylene and ethylbenzene are 3.79:1, 2.71:1, and 1.90:1, respectively) and ethylbenzene system using the same method.

[0127] like Figure 14 and 15 As shown, the saturated adsorption capacity is calculated according to X = (m2-m1) / (m1-m0)*1000.

[0128] Where X represents the saturated adsorption capacity, in mg / g;

[0129] m0 — Mass of the disposable plastic cup, in grams;

[0130] m1—The total mass of ZSM-5 molecular sieve after weighing, in g;

[0131] m2 — Mass after constant weight, in grams.

[0132] As shown in Table 2, the adsorption capacity of ZSM-5 molecular sieve for benzene series compounds was significantly improved after alkali treatment with 0.5 mol / L NaOH solution.

[0133] At room temperature, the saturated adsorption capacities of high-solids epoxy paint 380 solvent system, general-purpose epoxy paint 510 solvent system, acrylic silane low-resistivity self-smoothing antifouling paint (P) solvent system, xylene solvent system, and ethylbenzene solvent system increased from 76.276 mg / g, 67 mg / g, 81 mg / g, 70.50 mg / g, 80.08 mg / g, and 68.27 mg / g to 102.57 mg / g, 98.38 mg / g, 82.53 mg / g, 117.24 mg / g, and 90.89 mg / g, respectively, representing increases of 33.63%, 45.09%, 17.07%, 46.40%, and 33.15%.

[0134] Most studies have shown that VOCs components that are closer to the pore size of a molecular sieve are more easily adsorbed, and the static activity of molecular sieves in adsorbing different VOCs components is concentrated in the range of 20 mg / g to 300 mg / g.

[0135] Table 2: Saturated adsorption capacity of ZSM-5 molecular sieve

[0136]

[0137] Determination of desorption residue rate:

[0138] 5g of modified ZSM-5 molecular sieve was immersed in a petri dish containing xylene for 36h; the saturated adsorbed ZSM-5 molecular sieve was placed in an oven and desorbed at 100℃, 120℃, and 150℃ respectively, and weighed every 1h until constant weight was achieved; three parallel experiments were performed at each temperature; the desorption residue of ethylbenzene, high solid epoxy paint 380 solvent system, general epoxy paint 510 solvent system and acrylic silane low resistance self-smoothing antifouling paint (P) solvent system was measured using the same method; a comparative experiment was conducted with unmodified ZSM-5 molecular sieve.

[0139] Take 5g of unmodified ZSM-5 molecular sieve in a petri dish and dry it in an oven at 100℃, 120℃ and 150℃ until constant weight. Perform three sets of parallel experiments and calculate the weight loss rate.

[0140] Calculate the desorption residue using Y = (m2-m1) / (m1-m0)*1000;

[0141] Calculate the desorption residual rate using Z = Y / X * 100;

[0142] Calculate the corrected desorption residual rate using Z' = (Y + 1000 * Q) / X * 100.

[0143] Where m0 is the mass of the culture dish, in grams;

[0144] m1—The total weight of ZSM-5 molecular sieve after weighing, in grams;

[0145] m2—mass at constant weight, in grams;

[0146] Y—Desorption residue, mg / g;

[0147] Z—Desorption residual rate, %;

[0148] Z' — Corrected desorption residual rate, %;

[0149] Q—Weight loss rate of molecular sieve at desorption temperature.

[0150] Depend on Figures 16 to 20 As shown, the thermal desorption trends of ZSM-5 molecular sieves for various solvent systems at different temperatures are consistent before and after modification. Occasional anomalies are due to different experimental environments and operational procedures.

[0151] Due to limitations in the experimental method, variables were not controlled during the modification of ZSM-5 molecular sieve. Therefore, experiments were conducted on the unmodified molecular sieve at 100℃, 120℃, and 150℃ to obtain the weight loss rate. The theoretical weight loss rate of the modified ZSM-5 molecular sieve at 150℃ was also calculated. The results are shown in Table 3.

[0152] Table 3: Thermal desorption weight loss rate of ZSM-5 molecular sieve

[0153]

[0154] As shown in Tables 4 and 5, the desorption residual rate of the modified ZSM-5 molecular sieve for high-solidity epoxy paint 380 solvent system, general epoxy paint 510 solvent system, acrylic silane low-resistance self-smoothing antifouling paint (P) solvent system, xylene solvent system and ethylbenzene solvent system is lower than that before modification. At 100℃, it is only about 10%, even as low as 1 / 3 of the desorption residual rate of the unmodified ZSM-5 molecular sieve, and the thermal desorption effect is better.

[0155] The higher the thermal desorption temperature, the more complete the desorption of ZSM-5 molecular sieve. The optimal desorption temperature is 120℃.

[0156] At thermal desorption temperatures of 120℃ and 150℃, several desorption systems exhibited the anomalous phenomenon of weight loss, which is speculated to be due to the ZSM-5 molecular sieve absorbing water molecules from the air before the experiment.

[0157] Table 4: Desorption Residual Rate of ZSM-5 Molecular Sieves After Correction

[0158]

[0159] Table 5: Desorption time of ZSM-5 molecular sieve

[0160]

[0161]

[0162] In summary, ZSM-5 molecular sieves were modified by soaking them in sodium formate solutions of concentrations of 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, and 0.7 mol / L at a liquid-to-solid ratio (mL / g) of 4:1 for 3 h. After modification, a large number of mesopores were generated in the 2 nm to 3 nm range of ZSM-5 molecular sieves, and the contribution of mesopores to the total pore volume was increased. Among them, the alkali treatment modification effect was the best when the sodium formate solution concentration was 0.5 mol / L. As can be seen from the ATR-IR spectrum, there was no significant change in the infrared peaks before and after modification, indicating that the modification was only the removal of Si without significant structural changes. After alkali treatment with 0.5 mol / L sodium formate solution, the adsorption and desorption performance of ZSM-5 molecular sieves for benzene series compounds was significantly improved, with the adsorption capacity increasing by about 30%. The desorption residue rate at 100℃ was as low as 1 / 3 of that before modification, and the optimal thermal desorption temperature was 120℃.

[0163] ZSM-5 molecular sieves were modified by alkali treatment to expand their pores. N2 adsorption-desorption experiments were conducted to investigate the changes in their pore structure. Infrared spectroscopy was used to investigate their framework structure. Static adsorption and thermal desorption experiments were conducted to investigate the saturated adsorption of benzene series compounds by ZSM-5 molecular sieves before and after modification at room temperature and the desorption performance at different temperatures.

[0164] ZSM-5 molecular sieves were modified by soaking in sodium formate solutions of 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, and 0.7 mol / L for 3 h at a liquid-to-solid ratio (mL:g) of 4:1. Whole-pore tests were performed. ZSM-5 molecular sieves modified by alkali treatment with sodium formate solution of the optimal modification concentration were subjected to infrared spectroscopy, benzene series adsorption experiments, and thermal desorption experiments at 100℃, 120℃, and 150℃.

[0165] The following results were obtained through investigation:

[0166] It was found that a large number of mesopores were generated in the 2nm-3nm range after modification, and the contribution of mesopores to the total pore volume was increased. Specifically, when the sodium formate solution concentration was 0.5mol / L, S... meso / S BET and S meso / S micro The value is the largest, S micro / S BET The value is the lowest, and the alkali treatment has the best modification effect, among which S BET Let S be the surface area of ​​BET. meso S is the surface area of ​​the mesopores. micro S represents the surface area of ​​the micropores. meso / S BET S represents the proportion of mesoporous surface area to the total BET surface area. meso / S micro It is the ratio of the surface area of ​​mesopores to the surface area of ​​micropores.

[0167] According to ATR-IR, 550cm -1 The left and right sides are characteristic peaks of the five-membered ring, 800cm. -1 The left and right sides exhibit Si-O-Al symmetrical stretching vibration, 1100 cm⁻¹ -1 The left and right sides are skeletal vibrations. There is no significant change in the infrared peaks before and after modification. Modification only removes Si and does not significantly change the skeletal structure.

[0168] After being modified by alkaline treatment with 0.5 mol / L sodium formate solution, the adsorption and desorption performance of ZSM-5 molecular sieve for benzene series compounds is significantly improved. The adsorption capacity at room temperature can be increased by about 30%, and the desorption residual rate at 100℃ can be as low as 1 / 3 of that before modification, with 120℃ being the optimal desorption temperature.

[0169] Among them, gas chromatography was used to conduct detailed VOCs detection on three commercially available industrial coatings, identify the VOCs components, and accurately determine their content.

[0170] N2 adsorption-desorption tests were conducted to investigate the changes in pore parameters of ZSM-5 molecular sieve before and after alkali treatment with sodium formate solutions of different concentration gradients.

[0171] Infrared spectroscopy was conducted to investigate the structural changes of ZSM-5 molecular sieve before and after modification with sodium formate solution at the optimal modification concentration.

[0172] The saturated adsorption capacity of ZSM-5 molecular sieve for VOCs at room temperature and the desorption residual rate at 100℃, 120℃ and 150℃ were investigated by impregnation method and thermal desorption method before and after modification with sodium formate solution at the optimal modification concentration.

[0173] ZSM-5 molecular sieve powder, with the sample being ZSM-5-5, was modified by alkaline treatment with 0.5 mol / L sodium formate solution. This was used as an implementation method for preparing ZSM-5 modified molecular sieve blocks, which can be prepared based on 3D printing technology.

[0174] Specifically, the following steps are included:

[0175] S100. Powdered ZSM-5 modified molecular sieve is ground and mixed with kaolin and glass fiber to obtain a uniform powder. Carboxymethyl chitosan and pore-forming agent are added to water and mixed until a uniform gel-like substance is formed. Then, the mixture is added to the powder and mixed again to obtain a uniform paste-like mixture. The dry weight composition of the obtained paste-like mixture is: 15 wt% kaolin, 3 wt% glass fiber, 2 wt% pore-forming agent, 5 wt% carboxymethyl chitosan, and the remainder is powdered ZSM-5 modified molecular sieve.

[0176] S200. The paste mixture obtained in step S100 is subjected to ultrasonic treatment to eliminate air bubbles trapped in the paste and obtain a uniform paste mixture.

[0177] S300. Based on the required shape of the integral molecular sieve block, design the printing program using AutoCAD software;

[0178] S400: Place the uniform paste mixture obtained in step S200 into a 3D printing device and perform 3D printing to form a network structure of continuous molecular sieve rods.

[0179] S500. The product obtained in step S400 is subjected to low-temperature aging and shaping and high-temperature calcination to obtain an integral molecular sieve block. The low-temperature aging and shaping procedure is as follows: place in a freeze dryer, outdoor environment or oven for 2h to 72h, at a temperature of -10℃ to 50℃. The parameters for high-temperature calcination are as follows: heating program of 1℃ / min to 20℃ / min, calcination temperature of 400 to 800℃, and calcination time of 1 hour to 5 hours. The calcination atmosphere is air, vacuum or inert gas.

[0180] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A device for removing VOCs, characterized in that, include: Box; A rotating wheel, disposed within the housing, is divided into multiple geometrically congruent sector units along its circumference. The boundary line between adjacent sector units is a radial straight line passing through the center of the rotating wheel. Each sector unit includes a sector-shaped mounting groove, and each mounting groove is provided with a molecular sieve assembly. The end of the molecular sieve assembly near the center of the rotating wheel is rotatably connected to the end of the mounting groove near the center of the rotating wheel. The molecular sieve assembly is used to adsorb volatile organic compounds. A rotating assembly includes a gear ring, multiple gears meshing with the gear ring, at least one first drive mechanism, and multiple rotating shafts. The gear ring is fixedly disposed on the outer periphery of the rotating wheel along its circumference. The number of gears and rotating shafts corresponds to the number of mounting slots. The first drive mechanism is fixedly disposed outside the rotating wheel. The drive end of the first drive mechanism is fixedly connected to one of the gears. One end of the rotating shaft is fixedly connected to the gear, and the other end of the rotating shaft passes through the mounting slot and is fixedly connected to the end of the molecular sieve assembly away from the center of the rotating wheel. Alternatively, the rotating assembly includes multiple first drive mechanisms, multiple gears, and multiple rotating shafts. The number of first drive mechanisms, gears, and rotating shafts corresponds to the number of mounting slots. The first drive mechanism is fixedly disposed outside the rotating wheel. The drive end of the first drive mechanism is fixedly connected to the gear. One end of the rotating shaft is fixedly connected to the gear, and the other end of the rotating shaft passes through the mounting slot and is fixedly connected to the end of the molecular sieve assembly away from the center of the rotating wheel.

2. The VOCs removal apparatus according to claim 1, characterized in that, The sector-shaped unit also includes a rotating groove, which is disposed adjacent to the mounting groove and close to the center of the rotating wheel; The molecular sieve assembly includes a frame and a molecular sieve unit. The end of the frame away from the center of the rotating wheel is fixedly connected to the rotating shaft. A rotating ring is fixedly provided at the end of the frame near the rotating groove. The rotating ring is located in the rotating groove and is adapted to the rotating groove. The molecular sieve unit is disposed in the frame and is detachably connected to the frame.

3. The VOCs removal apparatus according to claim 2, characterized in that, The molecular sieve unit includes a first molecular sieve unit and a second molecular sieve unit; the first molecular sieve unit and the second molecular sieve unit are sequentially arranged in the frame from the outer edge of the rotor to the center of the rotor. A lifting groove is provided inside the frame near the rotating groove; The first molecular sieve unit is detachably connected to the frame via a screw, the second molecular sieve unit is detachably connected to the frame via a pusher assembly, and the first molecular sieve unit and the second molecular sieve unit are connected via an elastic element; The pushing assembly is located within the lifting groove. The pushing assembly includes a first wedge block, a second wedge block, a second driving mechanism, and a locking rod. The driving end of the second driving mechanism is fixedly connected to the first wedge block, and the second wedge block is fixedly connected to the locking rod. The inclined surface of the second wedge block abuts against the inclined surface of the first wedge block. The second driving mechanism drives the first wedge block to press the second wedge block, causing the second wedge block to rise. The driving direction of the second driving mechanism is perpendicular to the rising direction of the second wedge block. A first connecting rod is provided at one end of the second molecular sieve unit near the center of the rotor. The end of the locking rod away from the second wedge block is detachably connected to the first connecting rod.

4. The VOCs removal apparatus according to claim 3, characterized in that, The first connecting rod has a locking groove at one end near the locking rod; the locking rod has an electromagnetic lock at one end away from the second wedge block, and the lock cylinder of the electromagnetic lock is adapted to the locking groove.

5. The apparatus for removing VOCs according to claim 3 or 4, characterized in that, The first molecular sieve unit includes a first frame and a first elastic support plate disposed within the first frame. The first elastic support plate is disposed close to the second molecular sieve unit, and both ends of the first elastic support plate are fixedly connected to the first frame. The second molecular sieve unit includes a second frame and a second elastic support plate disposed within the second frame. The second elastic support plate is disposed away from the first molecular sieve unit, and both ends of the second elastic support plate are fixedly connected to the second frame. The second elastic support plate has the first connecting rod disposed on its surface away from the first molecular sieve unit, and the second frame has a through hole at one end away from the first frame. The first connecting rod passes through the through hole at one end away from the second elastic support plate. A second connecting rod is fixedly disposed on the surface of the first elastic support plate near the second frame, and the second connecting rod passes through the first frame and is fixedly connected to one end of the second frame near the first frame; A protective ring is provided at the edge of the first frame and the second frame that are close to each other.

6. The apparatus for removing VOCs according to claim 5, characterized in that, ZSM-5 modified molecular sieve blocks are provided between the interior of the first frame and the first elastic support plate, and between the interior of the second frame and the second elastic support plate.

7. The apparatus for removing VOCs according to claim 6, characterized in that, The preparation of the ZSM-5 modified molecular sieve bulk material includes the following steps: The modified ZSM-5 molecular sieve powder was ground and mixed with inorganic binder and inorganic fiber to obtain a mixed powder. Organic plasticizers and pore-forming agents are added to water and mixed to form a uniform gel. The mixed powder is mixed with the uniform gel to obtain a paste-like mixture; The paste mixture is ultrasonically treated to eliminate air bubbles trapped in it, resulting in a homogeneous paste mixture. The printing program is designed using AutoCAD software, and the uniform paste mixture is placed in a 3D printing device for 3D printing. Finally, the 3D printed product is subjected to low-temperature aging and shaping and high-temperature calcination to obtain ZSM-5 modified molecular sieve blocks.

8. The apparatus for removing VOCs according to claim 7, characterized in that, The preparation of the modified ZSM-5 molecular sieve powder includes the following steps: Prepare sodium formate solutions with concentrations ranging from 0.3 mol / L to 0.7 mol / L; Powdered ZSM-5 molecular sieve was immersed in the sodium formate solution, filtered under reduced pressure, and the resulting filter cake was dried at 120°C to constant weight and then crushed into powder to obtain modified ZSM-5 molecular sieve powder; the solid-liquid ratio of the ZSM-5 molecular sieve to the sodium formate solution was 1:4 g:mL.

9. The apparatus for removing VOCs according to claim 8, characterized in that, The concentration of the sodium formate solution is between 0.3 mol / L and 0.5 mol / L.

10. The apparatus for removing VOCs according to claim 2, characterized in that, The box body is also provided with a first support frame and a second support frame, which are arranged opposite to each other. The rotating wheel is arranged between the first support frame and the second support frame and is rotatably connected to the first support frame and the second support frame. The first support frame has a first cover on the top of the side away from the wheel, and the first cover includes a separately arranged air-gathering area and an air-guiding area; The second support frame has a second cover on the top side away from the rotating wheel. The second cover includes a separate air collection area and an air supply area. The gas gathering zone and the gas collecting zone are connected through the molecular sieve unit; the gas guiding zone and the gas supply zone are connected through the molecular sieve unit. The enclosure is equipped with an exhaust gas inlet pipe, an exhaust gas branch pipe, a heating pipe, and a connecting pipe; The inlet of the exhaust gas branch pipe is connected to the exhaust gas inlet pipe, and the outlet of the exhaust gas branch pipe is connected to the gas collection area. The inlet of the heating pipe is connected to the outlet of the gas collection area, and the outlet of the heating pipe is connected to the inlet of the gas supply area. A heater and a fan are installed on the heating pipe. The inlet of the connecting pipe is connected to the outlet of the air guiding zone.

11. The apparatus for removing VOCs according to claim 10, characterized in that, The second support frame is provided with a third drive mechanism, and the drive end of the third drive mechanism is fixedly connected to the rotating wheel; Multiple filter screens are provided on the side of the rotating wheel near the first support frame. The filter screens are arranged in a circular array on the rotating wheel, and flow sensors are provided on the filter screens. A sealing layer is provided between the molecular sieve assembly and the mounting groove.

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