A device for freely switching between air supply and air supply of a fume hood

Abstract

The present invention relates to the technical field of ventilation equipment, and more specifically, to a device for freely switching the supply and supply of air in a fume hood, comprising a fume hood body, a duct switching device provided on the top of the fume hood body, an air duct delivery portion connected to the end of the ventilation pipe body, and an air duct adjustment module provided on the outside of the pipe mouth of the extended pipe body. The device for freely switching the supply and supply of air in a fume hood, after the starting motor drives the rotating shaft to rotate, the upper connected gear shifts the cylinder wall tooth plate to drive the rotating cylinder to rotate inside the fixed bin body, and by controlling the rotation angle of the rotating cylinder, the air supply slot or the supply air slot on the annular cylinder body can be selected to dock with the ventilation pipe body. When using a single blower, the air supply system and the supply air system are combined, so that the air flow can selectively enter the air delivery duct from the supply air area or the supply air area of the ventilation pipe body, and finally be blown out by the duct adjustment bin, thereby simplifying the structure and reducing the large amount of power loss caused by the start and stop of the blower.

Description

Technical Field

[0001] The present invention relates to the technical field of ventilation equipment, in particular to a device for freely switching between air supply and air supply of a fume hood. Background Art

[0002] In laboratories, biopharmaceuticals, biological analysis, plant cultivation and other working environments, a large amount of harmful gases or waste gases are often generated in the work process. Once the concentration of these gases increases, it will have an adverse effect on the health of the staff. In order to discharge these gases from the working environment, fume hoods are often used; fume hoods, also known as fume hoods, are currently classified as a type of laboratory furniture by the mainstream industry. They are a first-level protective barrier to protect staff and play the role of local exhaust in the laboratory to protect scientific researchers and the laboratory environment.

[0003] Under normal circumstances, the fume hood will only activate the internal air supply system to bring fresh air from outside into the room to provide sufficient oxygen and dilute any harmful gases that may be present. At the same time, the exhaust system will also operate as needed to exhaust harmful gases or turbid air inside the laboratory to the outside. When the experiment produces harmful gases, the exhaust system will be fully activated and exhaust the harmful gases to the outside. At this time, in order to maintain indoor air pressure balance and air circulation, the air supply system is usually shut down and the air supply system is activated to replenish fresh air from outside. This results in the existing fume hoods having the air supply system and the air supply system running separately. The air supply duct and the air supply duct need to be installed outside the inner lining frame of the cabinet, and each duct needs to be equipped with a fan. At the same time, during the switching process between the air supply system and the air supply system, the fan in the external duct will always start and stop, which leads to a large amount of power loss.

[0004] In view of this, we propose a device for freely switching between supply and supplementary air in a fume hood.

[0005] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0006] The object of the present invention is to provide a device for freely switching between air supply and air supply of a fume hood, so as to solve the problems raised in the above-mentioned background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A device for freely switching between air supply and air supply of a fume hood, comprising a fume hood body, wherein an air duct switching device is provided on the top of the fume hood body;

[0009] The air duct switching device includes a fixed module, an air duct composite part arranged at the center of the fixed module, a rotating cylinder arranged inside the air duct composite part, a connecting part arranged outside the rotating cylinder, and two sets of transmission parts respectively arranged at the left and right sides of the connecting part;

[0010] The air duct composite part includes an annular plate, a ventilation pipe body provided on the outer side walls of the left and right ends of the annular plate, a plurality of air duct partition plates regularly provided on the inner side walls of the ventilation pipe body for separating the supply air area and the supply air area, and an air filter element provided inside the supply air channel;

[0011] The rotating cylinder includes an annular cylinder body and a cylinder wall tooth plate arranged near the top of the outer wall of the annular cylinder body. The inner wall of the annular cylinder body is provided with air supply grooves and air supply grooves symmetrically arranged in pairs near the bottom.

[0012] The end of the ventilation pipe body is connected to an air duct delivery part, which includes an air delivery duct, an extended pipe body provided on the outer wall of the air delivery duct, a pipe body partition plate provided inside the air delivery duct and the extended pipe body for separating the air supply area and the air supply area, and a plurality of air guide plates provided on the inner wall of the air delivery duct for changing the direction of air flow;

[0013] An air duct adjustment module is provided on the outside of the pipe mouth of the extended tube body, and the air duct adjustment module includes an air duct adjustment bin, a plurality of bending plates arranged between the inner walls at the upper and lower ends of the air duct adjustment bin, a wind block plate arranged at the air duct adjustment bin near the external bin mouth, an extension shaft arranged at the top position of the central axis of the wind block plate, and a shaft gear arranged at the top of the extension shaft.

[0014] In the technical solution of the present invention, the fume hood includes a placement cabinet for storing experimental supplies, a control console fixed by screws at the front end position of the placement cabinet top, an inner lining frame arranged on the top surface of the placement cabinet, an external frame fixed by screws to the top surfaces of the left and right ends of the placement cabinet, a protective window slidably connected to the inside of the slots of the outer side walls of the front ends of the two external frames, a side top plate fixed by snapping on the top of the external frame, a middle top mold fixed by screws between the inner side walls of the two external frames, an exhaust duct fixed by screws inside the middle top mold, and a front cover plate fixed by screws to the top of the outer side walls of the front ends of the two external frames, the middle top mold including a module plate body, two protective frames symmetrically welded and fixed to the front end of the bottom of the module plate body for protecting the extension axis, and a plate bottom bracket fixed by screws at the left and right ends of the bottom surface of the module plate body for providing a fixed position for the upper guide plate, and the top surface of the module plate body is provided with a square groove that runs through the top and bottom to provide a fixed interval for the exhaust duct.

[0015] In the technical solution of the present invention, the inner lining frame includes a rear frame plate fixedly connected to the top surface of the cabinet by screws, a number of plate brackets fixedly connected to the left and right ends of the front side wall of the rear frame plate by screws, a number of guide plates fixedly connected to the inside of the corresponding plate brackets by bolts at the left and right ends, and two side frame plates welded and fixed to the left and right front side walls of the rear frame plate, and the side frame plates are provided with plate slots for the protruding pipes to pass through.

[0016] In the technical solution of the present invention, the fixed module includes a fixed warehouse body and an extended warehouse body integrally formed at the front end position of the outer wall on both ends of the fixed warehouse body for providing a placement area for the transmission part; a warehouse top circular groove for providing a rotation area for the annular cylinder is opened near the center position on the top surface of the fixed warehouse body; a plurality of regularly distributed warehouse top openings are opened on the outside of the warehouse top circular groove on the top surface of the fixed warehouse body; warehouse wall through grooves adapted to the external dimensions of the ventilation pipe body are opened on the outer walls on both ends of the fixed warehouse body; a spherical limit block is slidably connected to the inside of the warehouse top opening; a pressure spring is welded and fixed to the bottom surface of the limit block; and the bottom end of the pressure spring is welded and fixed to the bottom hole wall of the warehouse top opening.

[0017] In the technical solution of the present invention, the bottom surface of the annular plate is welded and fixed to the bottom surface of the fixed bin body, the ventilation pipe body and the fixed bin body are integrally formed, the air duct partition plate is welded and fixed to the inner wall of the ventilation pipe body, and the top sealing plate of the air filter element is fixedly connected to the top surface of the air supply area inside the ventilation pipe body by screws.

[0018] In the technical solution of the present invention, the top end of the annular cylinder is rotatably connected to the inside of the circular groove on the silo top, and the top surface of the annular cylinder is provided with limiting holes with the same number, corresponding positions and sizes as the openings on the silo top. The sizes of the air supply groove and the air supply groove are respectively adapted to the longitudinal cross-sectional sizes of the air supply area and the air supply area of the ventilation pipe body separated by the air duct partition plate, and the cylinder wall tooth plate is welded and fixed to the outer wall of the annular cylinder.

[0019] In the technical solution of the present invention, the connecting part includes a rotating shaft with both upper and lower ends rotatably connected to the inner wall of the fixed warehouse body, an upper connecting gear fixedly connected to the outer wall of the rotating shaft near the upper position by a pin, a lower connecting gear fixedly connected to the outer wall of the rotating shaft near the lower position by a pin, and a motor fixedly connected to the top surface of the fixed warehouse body by bolts, and the output end of the motor passes through the top surface of the fixed warehouse body and is coaxially connected to the rotating shaft.

[0020] In the technical solution of the present invention, the transmission part includes two pulleys arranged in parallel on the left and right, a transmission belt mounted on the outside of the two pulleys, a docking gear fixedly connected to the position above the inner pulley by a pin, and a wheel body gear fixedly connected to the position above the outer pulley by a pin. The two pulleys are rotatably connected to the inner bottom surfaces of the fixed warehouse body and the extended warehouse body respectively, the docking gear is engaged with the lower connecting gear, and the wheel body gear is engaged with the shaft body gear.

[0021] In the technical solution of the present invention, the air duct is fixedly connected to the ventilation pipe body by bolts, the extended pipe body is integrally formed with the air duct, the number of the pipe body partition plates is the same as the number of the air duct partition plates and the positions correspond one to one, the air guide plate is welded and fixed to the inner wall of the air duct, the top surface of the air guide plate is inclined with the outside higher and the inside lower, and the outer side of the pipe mouth of the extended pipe body is fixedly connected to the inner groove wall of the groove of the plate body by screws.

[0022] In the technical solution of the present invention, the air duct adjustment bin is clamped and fixed to the extended tube body, the bent plate is welded and fixed to the inner wall of the air duct adjustment bin, the upper and lower ends of the central axis of the wind block plate are rotatably connected to the inner walls of the upper and lower ends of the air duct adjustment bin, the bottom end of the extension shaft is clamped and fixed to the central axis of the wind block plate, the top end of the extension shaft is rotatably connected to the inner wall of the extension bin body, and the shaft gear is fixed to the outer wall of the top end of the extension shaft through a bayonet.

[0023] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0024] 1. This device for freely switching between supply and supply air in a fume hood starts the motor to drive the rotating shaft to rotate, and then the upper connected gear shifts the toothed plate on the cylinder wall to drive the rotating cylinder to rotate inside the fixed bin body. By controlling the rotation angle of the rotating cylinder, the air supply slot or the supply air slot on the annular cylinder can be selected to dock with the ventilation pipe body. When using one fan, the air supply system and the supply air system are combined, so that the air flow can selectively enter the air duct from the air supply area or the supply air area of the ventilation pipe body, and finally be blown out by the air duct adjustment bin, which simplifies the structure and reduces the large amount of power loss caused by starting and stopping the fan.

[0025] 2. The device for freely switching between supply and replenishment air in the fume hood, the transmission part in the air duct switching device cooperates with the air duct adjustment module. When the lower connecting gear rotates, the wheel body gear can be driven to rotate through the pulley and the transmission belt, and the shaft body gear is driven to rotate together with the extension shaft, thereby changing the relative position of the wind blocking plate, thereby adjusting the size of the air outlet of the air duct adjustment bin, ensuring that the flow rate of the air flow blown out of the air duct adjustment bin is stable when supplying or replenishing air, and preventing backflow. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 This is a schematic diagram of the structural disassembly of the fume hood body of the present invention;

[0028] Figure 3 It is a structural schematic diagram of the inner lining frame in the present invention;

[0029] Figure 4 Schematic diagram of the structure of the middle top plate of the present invention;

[0030] Figure 5 It is a structural cutaway side view of the fume hood body of the present invention;

[0031] Figure 6 It is a partial structural diagram of the present invention;

[0032] Figure 7 It is a schematic cross-sectional view of the structure of the air duct switching device of the present invention;

[0033] Figure 8 It is a structural diagram of the fixing module in the present invention;

[0034] Figure 9 It is an enlarged schematic diagram of part A of the present invention;

[0035] Figure 10 Schematic diagram of the structure of the air duct composite part of the present invention;

[0036] Figure 11 It is a partial structural diagram of the air duct switching device in the present invention;

[0037] Figure 12 It is a structural schematic diagram of the rotating drum in the present invention;

[0038] Figure 13 Schematic diagram of the structure of the connecting portion of the present invention;

[0039] Figure 14 It is a schematic diagram of the structural disassembly of the transmission part in the present invention;

[0040] Figure 15 It is a schematic cross-sectional view of the structure of the air duct conveying portion of the present invention;

[0041] Figure 16 This is a structural diagram of the air duct adjustment module of the present invention;

[0042] Figure 17 It is a structural cutaway top view of the air duct adjustment module of the present invention.

[0043] Description of reference numerals:

[0044] 1. Fume cabinet; 10. Cabinet placement; 11. Control console; 12. Liner frame; 120. Rear frame; 121. Panel bracket; 122. Air guide plate; 123. Side frame; 1230. Panel slot; 13. Protective window; 14. External frame; 15. Side top plate; 16. Middle top mold; 160. Module panel; 161. Protective frame; 162. Panel bottom bracket; 17. Exhaust duct; 18. Front cover

[0045] 2. Air duct switching device; 20. Fixed module; 201. Fixed silo; 2010. Silo top circular groove; 2011. Silo top opening; 2012. Silo wall through groove; 202. Stop block; 203. Pressure spring; 204. Extended silo; 21. Air duct composite part; 210. Annular plate; 211. Ventilation pipe body; 212. Air duct partition plate; 213. Air filter element; 22. Rotating cylinder; 220. Annular cylinder; 2201. Supply air slot; 2202. Supplement air slot; 2203. Stop hole; 221. Cylinder wall tooth plate; 23. Connecting part; 230. Rotating shaft; 231. Upper connecting gear; 232. Lower connecting gear; 233. Motor; 24. Transmission part; 240. Pulley; 241. Transmission belt; 242. Docking gear; 243. Wheel body gear;

[0046] 3. Air duct delivery unit; 30. Air delivery duct; 31. Extended tube body; 32. Tube body partition plate; 33. Air guide plate;

[0047] 4. Air duct adjustment module; 40. Air duct adjustment chamber; 41. Bending plate; 42. Wind blocking plate; 43. Extension shaft; 44. Shaft gear. DETAILED DESCRIPTION

[0048] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0049] See also Figures 1-17 As shown, the present invention provides a technical solution:

[0050] A device for freely switching between air supply and air supply of a fume hood, comprising a fume hood body 1, with an air duct switching device 2 provided on the top of the fume hood body 1;

[0051] In the present invention, the fume hood 1 includes a cabinet 10 for storing experimental supplies, a console 11 fixedly connected to the front end position of the top of the cabinet 10 by screws, an inner lining frame 12 arranged on the top surface of the cabinet 10, an outer frame 14 fixedly connected to the top surfaces of the left and right ends of the cabinet 10 by screws, a protective window 13 slidably connected to the inner groove of the outer side wall of the front end of the two outer frames 14, a side top plate 15 fixedly connected to the top of the outer frame 14, a middle top mold 16 fixedly connected between the inner side walls of the two outer frames 14 by screws, and a The exhaust duct 17 connected to the interior of the middle top mold 16 and the front cover 18 fixedly connected to the top of the outer side walls of the front ends of the two outer frames 14 by screws, the middle top mold 16 includes a module plate 160, two protective frames 161 symmetrically welded and fixed to the front end of the bottom of the module plate 160 for protecting the extension shaft 43, and plate bottom brackets 162 fixedly connected to the left and right ends of the bottom surface of the module plate 160 by screws for providing a fixed position for the upper guide plate 122. The top surface of the module plate 160 is opened with a square groove running through it from top to bottom to provide a fixed area for the exhaust duct 17;

[0052] Furthermore, the console 11 is used to facilitate the operator to control the internal equipment of the fume hood 1, the protective window 13 is used to protect the safety of the operator and prevent air flow from overflowing, the external frame 14, the side top plate 15 and the front cover plate 18 are all used to ensure the strength of the overall structure of the fume hood 1, the module plate 160 in the middle top mold 16 is used to provide a fixed platform for the air duct switching device 2, and the exhaust channel 17 is used to connect to an external exhaust system.

[0053] In the present invention, the inner lining frame 12 includes a rear frame plate 120 fixedly connected to the top surface of the cabinet 10 by screws, a plurality of plate brackets 121 fixedly connected to the left and right ends of the front side wall of the rear frame plate 120 by screws, a plurality of guide plates 122 fixedly connected to the inside of the corresponding plate brackets 121 by bolts at the left and right ends, and two side frame plates 123 welded and fixed to the left and right front side walls of the rear frame plate 120. The side frame plates 123 are provided with plate slots 1230 for the extended tube 31 to pass through.

[0054] Furthermore, the rear frame plate 120 and the side frame plate 123 are used to ensure the sealing of the internal structure of the fume hood 1, and the plate bracket 121 is used to provide a fixed base point for the guide plate 122. The guide plate 122 is used to enable the gas inside the fume hood 1 to flow to the exhaust channel 17 faster after the exhaust system is started.

[0055] In this implementation, if Figure 7-14As shown, the air duct switching device 2 includes a fixed module 20, an air duct composite portion 21 disposed at the center of the fixed module 20, a rotating cylinder 22 disposed inside the air duct composite portion 21, a connecting portion 23 disposed outside the rotating cylinder 22, and two sets of transmission portions 24 disposed on the left and right sides of the connecting portion 23 respectively;

[0056] Furthermore, the fixed module 20 includes a fixed warehouse body 201 and an extended warehouse body 204 integrally formed at the front end position of the outer side walls of the left and right ends of the fixed warehouse body 201 for providing a placement area for the transmission part 24, a warehouse top circular groove 2010 for providing a rotation area for the annular cylinder 220 is opened near the center position on the top surface of the fixed warehouse body 201, a plurality of regularly distributed warehouse top openings 2011 are opened on the outside of the warehouse top circular groove 2010 on the top surface of the fixed warehouse body 201, warehouse wall through grooves 2012 that are adapted to the external dimensions of the ventilation pipe body 211 are opened on the outer side walls of the left and right ends of the fixed warehouse body 201, a spherical top limit block 202 is slidably connected to the interior of the warehouse top opening 2011, a pressure spring 203 is welded and fixed to the bottom surface of the limit block 202, and the bottom end of the pressure spring 203 is welded and fixed to the bottom hole wall of the warehouse top opening 2011;

[0057] Furthermore, the fixed bin body 201 is used to ensure the strength of the overall structure of the fixed module 20, and the bin top opening 2011 is used to provide storage space for the limit block 202 and the pressure spring 203. During the rotation of the rotating cylinder 22, the annular cylinder 220 squeezes the limit block 202, causing the pressure spring 203 to contract. When the annular cylinder 220 moves to the air supply or air supply position, the limit block 202 enters the interior of the limit hole 2203 under the elastic action of the pressure spring 203, ensuring the stability of the position of the rotating cylinder 22 after rotation.

[0058] In the present invention, the air duct composite part 21 includes an annular plate 210, a ventilation pipe body 211 provided on the outer side walls of the left and right ends of the annular plate 210, a plurality of air duct partition plates 212 regularly provided on the inner side walls of the ventilation pipe body 211 for separating the supply air area and the supply air area, and an air filter element 213 provided inside the supply air duct.

[0059] Furthermore, the bottom surface of the annular plate 210 is welded and fixed to the bottom surface of the fixed bin body 201, the ventilation pipe body 211 and the fixed bin body 201 are integrally formed, the air duct partition plate 212 is welded and fixed to the inner wall of the ventilation pipe body 211, and the top sealing plate of the air filter element 213 is fixedly connected to the top surface of the air supply area inside the ventilation pipe body 211 by screws.

[0060] Furthermore, the annular plate 210 is used to ensure the stability of the overall structure of the air duct composite part 21, the air duct partition plate 212 inside the ventilation tube body 211 is used to separate the air supply area and the air supply area, and the air filter element 213 is used to filter the air flow sent by the fan into the air supply area.

[0061] In this embodiment, Figure 11-12 As shown, the rotating cylinder 22 includes an annular cylinder 220 and a cylinder wall tooth plate 221 provided on the outer wall of the annular cylinder 220 near the top position, and the inner wall of the annular cylinder 220 near the bottom position is respectively provided with a group of two air supply slots 2201 and a symmetrical arrangement of air supply slots 2202;

[0062] Furthermore, the top end of the annular cylinder 220 is rotatably connected to the inside of the circular groove 2010 on the silo top, and the top surface of the annular cylinder 220 is provided with limiting holes 2203, which are the same in number, correspond in position and are of the same size as the silo top openings 2011. The sizes of the air supply groove 2201 and the air supply groove 2202 are respectively adapted to the longitudinal cross-sectional dimensions of the air supply area and the air supply area of the ventilation pipe body 211 separated by the air duct partition plate 212, and the cylinder wall tooth plate 221 is welded and fixed to the outer wall of the annular cylinder 220.

[0063] Furthermore, the annular cylinder 220 is used to ensure the strength of the overall structure of the rotating cylinder 22, and the cylinder wall tooth plate 221 enables the rotating cylinder 22 as a whole to rotate under the drive of the upper connecting gear 231, so that the ventilation pipe body 211 can be connected with the air supply groove 2201 or the air supply groove 2202.

[0064] In this embodiment, Figure 13 As shown, the connecting portion 23 includes a rotating shaft 230 rotatably connected to the inner wall of the fixed warehouse body 201 at both ends, an upper connecting gear 231 fixedly connected to the outer wall of the rotating shaft 230 near the upper position by a bayonet, a lower connecting gear 232 fixedly connected to the outer wall of the rotating shaft 230 near the lower position by a bayonet, and a motor 233 fixedly connected to the top surface of the fixed warehouse body 201 by bolts. The output end of the motor 233 passes through the top surface of the fixed warehouse body 201 and is coaxially connected to the rotating shaft 230.

[0065] Furthermore, after the motor 233 is connected to an external power source and started, it can drive the rotating shaft 230 to rotate, and drive the upper connecting gear 231 and the lower connecting gear 232 to rotate together, thereby driving the rotating cylinder 22 and the docking gear 242 in the transmission part 24 to rotate respectively.

[0066] In this embodiment, Figure 14As shown, the transmission part 24 includes two pulleys 240 arranged in parallel on the left and right, a transmission belt 241 sleeved on the outside of the two pulleys 240, a docking gear 242 fixedly connected to a position above the inner pulley 240 by a bayonet, and a wheel body gear 243 fixedly connected to a position above the outer pulley 240 by a bayonet. The two pulleys 240 are rotatably connected to the inner bottom surfaces of the fixed warehouse body 201 and the extended warehouse body 204 respectively. The docking gear 242 is meshed with the lower connecting gear 232, and the wheel body gear 243 is meshed with the shaft gear 44.

[0067] Furthermore, after the docking gear 242 is rotated by the lower connecting gear 232 , the two sets of pulleys 240 are driven to rotate simultaneously through the transmission belt 241 , thereby driving the wheel body gear 243 to rotate.

[0068] In the present invention, the end of the ventilation pipe body 211 is connected to the air duct delivery part 3, which includes an air delivery duct 30, an extended pipe body 31 provided on the outer wall of the air delivery duct 30, a pipe body partition plate 32 provided inside the air delivery duct 30 and the extended pipe body 31 for separating the supply air area and the air supply area, and a plurality of air guide plates 33 provided on the inner wall of the air delivery duct 30 for changing the air flow direction.

[0069] Specifically, the air duct 30 is fixedly connected to the ventilation pipe body 211 by bolts, the extended pipe body 31 and the air duct 30 are integrally formed, the number of pipe body partition plates 32 is the same as the number of air duct partition plates 212 and the positions correspond one to one, the air guide plate 33 is welded and fixed to the inner wall of the air duct 30, and the top surface of the air guide plate 33 is inclined with the outside higher and the inside lower, and the outer side of the pipe mouth of the extended pipe body 31 is fixedly connected to the inner groove wall of the plate groove 1230 by screws.

[0070] Furthermore, the air duct 30 is used to ensure the strength of the overall structure of the air duct conveying part 3, the extended tube body 31 is used to provide a fixed base point for the air duct adjustment module 4 inside the fume hood 1, the tube body partition plate 32 is used to still separate the air supply area and the air supply area inside the air duct 30, and the air guide plate 33 is used to change the direction of the airflow.

[0071] In this implementation, if Figure 16-17 As shown, an air duct adjustment module 4 is provided on the outside of the nozzle of the extended tube body 31. The air duct adjustment module 4 includes an air duct adjustment chamber 40, a plurality of bent plates 41 provided between the inner side walls at the upper and lower ends of the air duct adjustment chamber 40, a choke plate 42 provided near the outer chamber opening of the air duct adjustment chamber 40, an extension shaft 43 provided at the top end of the central axis of the choke plate 42, and a shaft gear 44 provided at the top of the extension shaft 43.

[0072] Furthermore, the air duct adjustment bin 40 is clamped and fixed to the extended tube body 31, the bent plate 41 is welded and fixed to the inner wall of the air duct adjustment bin 40, the upper and lower ends of the central axis of the wind blocking plate 42 are rotatably connected to the inner walls of the upper and lower ends of the air duct adjustment bin 40, the bottom end of the extension shaft 43 is clamped and fixed to the central axis of the wind blocking plate 42, the top end of the extension shaft 43 is rotatably connected to the inner wall of the extension bin body 204, and the shaft gear 44 is fixedly connected to the outer wall of the top end of the extension shaft 43 by a bayonet.

[0073] Furthermore, the air duct adjustment chamber 40 is used to ensure the strength of the overall structure of the air duct adjustment module 4, and the bending plate 41 is used to change the direction of the air flow after it is blown out from the extended tube body 31. The shaft gear 44 rotates under the drive of the wheel gear 243, and drives the extension shaft 43 together with the wind blocking plate 42 to rotate. The wind blocking plate 42 controls the size of the air outlet of the air duct adjustment chamber 40, so that the air flow blown out from the air outlet of the air duct adjustment chamber 40 always remains stable during air supply and air replenishment.

[0074] Finally, it should be noted that the console 11 and motor 233 involved in the present invention are all universal standard parts or components known to those skilled in the art. Their structures and principles are known to those skilled in the art through technical manuals or conventional experimental methods. In the idle space of this device, the console 11 and the motor 233 are connected to the external power supply through wires. The specific connection means should refer to the working principle of the present invention. The electrical connections between the electrical components are completed in a sequential working order, and the detailed connection means are all well-known technologies in the art.

[0075] When the device for freely switching between supply and replenishment air of a fume hood of the present invention is used, first, when the fume hood body 1 needs to supply air, the motor 233 in the connecting portion 23 of the air duct switching device 2 is started, driving the rotating shaft 230 to rotate together with the upper connecting gear 231 and the lower connecting gear 232;

[0076] As the upper connecting gear 231 rotates, the rotating cylinder 22 as a whole rotates inside the fixed chamber 201. After the air supply slot 2201 on the annular cylinder 220 is docked with the ventilation pipe 211, the motor 233 is turned off.

[0077] At this time, as the lower connecting gear 232 rotates, the docking gear 242 rotates, which in turn drives the two sets of pulleys 240 to rotate, and then drives the wheel body gear 243 to rotate, thereby turning the shaft body gear 44 to rotate and change the fixed position of the air blocking plate 42, so that the position of the air blocking plate 42 is parallel to the air outlet cross section of the air duct adjustment chamber 40;

[0078] The fan in the external duct delivers external air into the air supply area of the ventilation pipe body 211, which is then filtered by the air filter element 213 and enters the air delivery duct 30, and is blown out from the air duct adjustment chamber 40;

[0079] Next, when the fume hood 1 needs to discharge the generated harmful gases, the exhaust system is started and the motor 233 is restarted, so that the air supply groove 2202 on the annular cylinder 220 in the rotating cylinder 22 is connected to the ventilation pipe body 211. At this time, the position of the wind blocking plate 42 is changed again under the action of the transmission part 24, and is perpendicular to the air outlet cross section of the air duct adjustment chamber 40.

[0080] The fan in the external pipe sends the air flow into the air supply area of the ventilation pipe body 211, directly enters the air supply pipe 30, and is blown out from the air duct adjustment chamber 40, so as to balance the air pressure and ensure air circulation.

[0081] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for freely switching between air supply and air supply of a fume hood, comprising a fume hood body (1), characterized in that: An air duct switching device (2) is provided on the top of the fume hood (1); The air duct switching device (2) comprises a fixed module (20), an air duct composite portion (21) arranged at a central position inside the fixed module (20), a rotating cylinder (22) arranged inside the air duct composite portion (21), a connecting portion (23) arranged outside the rotating cylinder (22), and two sets of transmission portions (24) respectively arranged at left and right sides of the connecting portion (23); The air duct composite portion (21) comprises an annular plate (210), a ventilation pipe body (211) arranged on the outer side walls of the left and right ends of the annular plate (210), a plurality of air duct partition plates (212) regularly arranged on the inner side walls of the ventilation pipe body (211) for separating the air supply area and the air supply area, and an air filter element (213) arranged inside the air supply channel; The rotating cylinder (22) comprises an annular cylinder (220) and a cylinder wall tooth plate (221) arranged on the outer wall of the annular cylinder (220) near the top position, and the inner wall of the annular cylinder (220) near the bottom position is respectively provided with air supply grooves (2201) and air supply grooves (2202) arranged in pairs and symmetrically. An air duct delivery portion (3) is connected to the end of the ventilation pipe body (211), and the air duct delivery portion (3) comprises an air delivery pipe (30), an extended pipe body (31) arranged on the outer wall of the air delivery pipe (30), a pipe body partition plate (32) arranged inside the air delivery pipe (30) and the extended pipe body (31) for separating the air supply area and the air supply area, and a plurality of air guide plates (33) arranged on the inner wall of the air delivery pipe (30) for changing the direction of air flow; An air duct adjustment module (4) is provided on the outside of the pipe opening of the extended pipe body (31), and the air duct adjustment module (4) comprises an air duct adjustment chamber (40), a plurality of bending plates (41) provided between the inner side walls at the upper and lower ends of the air duct adjustment chamber (40), a wind blocking plate (42) provided near the outer chamber opening of the air duct adjustment chamber (40), an extension shaft (43) provided at the top end of the central axis of the wind blocking plate (42), and a shaft gear (44) provided at the top of the extension shaft (43).

2. The device for freely switching between supply and supplementary air in a fume hood according to claim 1, characterized in that: The fume hood (1) comprises a cabinet (10) for storing experimental supplies, a control console (11) fixedly connected to the front end position of the top of the cabinet (10) by screws, an inner lining frame (12) arranged on the top surface of the cabinet (10), an outer frame (14) fixedly connected to the top surfaces of the left and right ends of the cabinet (10) by screws, a protective window (13) slidably connected to the inner groove of the outer side walls of the front ends of the two outer frames (14), a side top plate (15) fixedly connected to the top of the outer frame (14), a middle top mold (16) fixedly connected between the inner side walls of the two outer frames (14) by screws, and a middle top mold (16) fixedly connected to the middle The top mold (16) includes an exhaust passage (17) inside the top mold and a front cover plate (18) fixedly connected to the top of the outer side walls of the front ends of the two outer frames (14) by screws. The middle top mold (16) includes a module plate body (160), two protective frames (161) symmetrically welded and fixed to the front end of the bottom of the module plate body (160) for protecting the extension shaft (43), and a plate bottom bracket (162) fixedly connected to the left and right ends of the bottom surface of the module plate body (160) by screws for providing a fixed position for the upper guide plate (122). The top surface of the module plate body (160) is provided with a square groove that runs through from top to bottom and is used to provide a fixed interval for the exhaust passage (17).

3. The device for freely switching between supply and supplementary air in a fume hood according to claim 2, characterized in that: The inner lining frame (12) comprises a rear frame plate (120) fixedly connected to the top surface of the cabinet (10) by screws, a plurality of plate brackets (121) fixedly connected to the left and right ends of the front side wall of the rear frame plate (120) by screws, a plurality of guide plates (122) fixedly connected to the inside of the corresponding plate brackets (121) by bolts at the left and right ends, and two side frame plates (123) welded and fixed to the left and right ends of the front side walls of the rear frame plate (120), wherein the side frame plates (123) are provided with plate slots (1230) for the extension pipe (31) to pass through.

4. The device for freely switching between supply and supply air for a fume hood according to claim 1, characterized in that: The fixed module (20) comprises a fixed warehouse body (201) and an extended warehouse body (204) integrally formed at the front end positions of the outer side walls of the left and right ends of the fixed warehouse body (201) for providing a placement area for the transmission part (24). A warehouse top circular groove (2010) for providing a rotation area for the annular cylinder (220) is opened near the center position on the top surface of the fixed warehouse body (201). The top surface of the fixed warehouse body (201) is provided with a plurality of regular grooves outside the warehouse top circular groove (2010). The silo top openings (2011) are distributed, and silo wall through grooves (2012) that are compatible with the external dimensions of the ventilation pipe body (211) are opened on the outer walls of the left and right ends of the fixed silo body (201). The interior of the silo top opening (2011) is slidably connected to a limit block (202) with a spherical top. A pressure spring (203) is welded and fixed on the bottom surface of the limit block (202), and the bottom end of the pressure spring (203) is welded and fixed to the bottom hole wall of the silo top opening (2011).

5. The device for freely switching between supply and supplementary air in a fume hood according to claim 4, characterized in that: The bottom surface of the annular plate (210) is welded and fixed to the bottom surface of the fixed silo (201); the ventilation pipe body (211) and the fixed silo (201) are integrally formed; the air duct partition plate (212) is welded and fixed to the inner side wall of the ventilation pipe body (211); and the top sealing plate of the air filter element (213) is fixedly connected to the top surface of the air supply area inside the ventilation pipe body (211) by screws.

6. The device for freely switching between supply and supplementary air in a fume hood according to claim 4, characterized in that: The top end of the annular cylinder (220) is rotatably connected to the inside of the silo top circular groove (2010), and the top surface of the annular cylinder (220) is provided with limiting holes (2203) with the same number, corresponding positions and sizes as the silo top openings (2011). The sizes of the air supply groove (2201) and the air supply groove (2202) are respectively adapted to the longitudinal cross-sectional dimensions of the air supply area and the air supply area separated by the air duct partition plate (212) of the ventilation pipe body (211). The cylinder wall tooth plate (221) is welded and fixed to the outer wall of the annular cylinder (220).

7. The device for freely switching between supply and supplementary air in a fume hood according to claim 4, characterized in that: The connecting portion (23) comprises a rotating shaft (230) with both upper and lower ends rotatably connected to the inner wall of the fixed warehouse body (201), an upper connecting gear (231) fixedly connected to the outer wall of the rotating shaft (230) near the upper position through a bayonet, a lower connecting gear (232) fixedly connected to the outer wall of the rotating shaft (230) near the lower position through a bayonet, and a motor (233) fixedly connected to the top surface of the fixed warehouse body (201) through a bolt, wherein the output end of the motor (233) passes through the top surface of the fixed warehouse body (201) and is coaxially connected to the rotating shaft (230).

8. The device for freely switching between supply and supplementary air in a fume hood according to claim 7, characterized in that: The transmission part (24) comprises two pulleys (240) arranged in parallel on the left and right sides, a transmission belt (241) sleeved on the outside of the two pulleys (240), a docking gear (242) fixedly connected to a position above the inner pulley (240) through a bayonet, and a wheel body gear (243) fixedly connected to a position above the outer pulley (240) through a bayonet. The two pulleys (240) are rotatably connected to the inner bottom surfaces of the fixed warehouse body (201) and the extended warehouse body (204), respectively. The docking gear (242) and the lower connecting gear (232) are meshed with each other, and the wheel body gear (243) and the shaft body gear (44) are meshed with each other.

9. The device for freely switching between supply and supplementary air in a fume hood according to claim 3, characterized in that: The air duct (30) is fixedly connected to the ventilation pipe body (211) by bolts. The extended pipe body (31) and the air duct (30) are integrally formed. The number of the pipe body partition plates (32) is the same as the number of the air duct partition plates (212) and their positions correspond one to one. The air guide plate (33) is welded and fixed to the inner wall of the air duct (30). The top surface of the air guide plate (33) is tilted with the outer side higher and the inner side lower. The outer side of the pipe mouth of the extended pipe body (31) is fixedly connected to the inner groove wall of the plate body slot (1230) by screws.

10. The device for freely switching between supply and supplementary air in a fume hood according to claim 4, characterized in that: The air duct adjustment chamber (40) is fixedly connected to the extended tube body (31), the bent plate (41) is welded and fixed to the inner wall of the air duct adjustment chamber (40), the upper and lower ends of the central axis of the wind blocking plate (42) are rotatably connected to the inner walls of the upper and lower ends of the air duct adjustment chamber (40), the bottom end of the extension shaft (43) is fixedly connected to the central axis of the wind blocking plate (42), the top end of the extension shaft (43) is rotatably connected to the inner wall of the extension chamber body (204), and the shaft gear (44) is fixedly connected to the outer wall of the top end of the extension shaft (43) through a bayonet.

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