Positive pressure isolation dust toxin, isolation virus dynamic air supply system

Abstract

The present application relates to a positive pressure isolation dust and virus isolation power air supply system, belonging to the technical field of protective equipment. The system comprises a protective head cover, a fan-shaped air pipe, a gas conveying hose, a quick pipe joint and a power air blower. The fan-shaped air pipe is arranged on the inner side of the protective head cover. One end of the fan-shaped air pipe extends to the front of the inner side of the protective head cover, and the other end of the fan-shaped air pipe extends to the back of the inner side of the protective head cover. The gas conveying hose is connected to the fan-shaped air pipe at the back of the inner side of the protective head cover through the quick pipe joint. The gas conveying hose is in communication with the protective head cover. The other end of the gas conveying hose is connected to the power air blower through a blower connecting head. The power air blower is in communication with the gas conveying hose. The system can deliver clean air to the face of the wearer through the gas conveying hose by the power air blower, so as to quickly take away the hot air exhaled by the wearer and prevent the perspective window on the air-permeable cloth cover from fogging. The system can be assembled by inserting the connecting elbow into the lock tongue sleeve, tightening the lock tongue ring and shortening the assembly time.

Description

Technical Field

[0001] This invention relates to a positive pressure power supply system for isolating dust and toxic substances and viruses, belonging to the technical field of protective equipment. Background Technology

[0002] In clinical, epidemic prevention, or dusty work environments, protective headgear is often provided to ensure the personal safety of staff. These headgear are usually sealed to effectively isolate dust, smoke, bacteria, and germs in the air.

[0003] Existing protective hoods typically use a strap-on design, which easily causes marks on the faces of medical personnel, resulting in discomfort. Furthermore, poor internal airflow can lead to breathing difficulties with prolonged wear, and condensation on the transparent viewing window can obstruct vision. While some protective hoods connect to air respirators via flexible hoses and connectors to ensure airflow, these threaded connections lack a locking mechanism, making them prone to loosening, leaks, and even detachment, posing significant safety hazards. Therefore, improvements are necessary. Summary of the Invention

[0004] The purpose of this invention is to provide a positive pressure power air supply system for isolating dust, toxic substances, and viruses that is easy to wear, does not leave marks, and solves the problems of poor air circulation in existing protective isolation headgear, which easily causes breathing difficulties for workers and generates moisture, obstructing workers' vision, and the complex operation procedures and major safety hazards of existing quick-connect pipe joints.

[0005] The present invention achieves the above objectives through the following technical solutions.

[0006] A positive pressure power supply ventilation system for isolating dust, toxic substances, and viruses includes a protective hood, an air supply hose, and a power supply fan. The system is characterized by: a fan-shaped duct inside the protective hood, one end of which extends to the front of the inner side of the hood, and the other end extending to the rear of the inner side of the hood. An air supply hose is attached to the fan-shaped duct extending to the rear of the inner side of the hood via a quick-connect fitting. The air supply hose is connected to the protective hood, and the other end of the air supply hose is connected to the power supply fan via a fan connector. The power supply fan is connected to the air supply hose.

[0007] The protective hood includes a hood body, an airtight fabric cover, a viewing window, and an adjustable headband. The airtight fabric cover is fitted over the hood body, and the airtight fabric cover has a viewing window. An elastic band is installed at the bottom of the airtight fabric cover, and an adjustable headband is installed on the hood body.

[0008] The power blower includes a blower housing, a battery, a filter assembly, and a blower rear cover. The top of the blower housing has an air outlet, the bottom of the blower housing has a battery, the front of the blower housing has symmetrical air inlets, a centrifugal fan is installed in the air inlet, the centrifugal fan is electrically connected to the battery, the front end of the blower housing has a filter assembly, and the back of the blower housing has a blower rear cover.

[0009] The filter assembly includes a secondary filter element, a primary filter element, and an outer cover. The outer cover is fastened to the power blower. A secondary filter element is disposed between the power blower and the outer cover. A primary filter element is mounted on the surface of the outer cover. The primary filter element is connected to the power blower through the secondary filter element.

[0010] The front end of the fan housing is provided with a locking hook. An unlocking switch is movably installed on the fan housing behind one of the locking hooks. A locking tooth is provided on the protective shell corresponding to the locking hook. The locking tooth engages with the locking hook and is intermittently connected to the unlocking switch.

[0011] The quick-connect fitting includes a connecting elbow, a locking tongue sleeve, a locking tongue ring, a locking tongue, and a locking pipe sleeve. The upper end of the locking pipe sleeve is threaded with a locking tongue sleeve, and the locking pipe sleeve has an internal thread. A locking tongue ring is fitted onto the locking tongue sleeve at the upper end of the locking pipe sleeve. Two sets of locking tongues are symmetrically engaged on the locking tongue sleeve inside the locking tongue ring. A connecting elbow is inserted into the upper end of the locking tongue sleeve. The locking tongue and the connecting elbow are intermittently engaged, and the connecting elbow is sealed and engaged with the fan-shaped duct.

[0012] The locking tongue sleeve has a "stepped structure"; the thin section of the locking tongue sleeve has an external thread on its circumferential surface; the locking tongue sleeve port below the external thread has a "conical" pressing edge; the thick section of the locking tongue sleeve has a positioning ring ridge on its circumferential surface; symmetrical locking through holes are provided on the circumferential surface of the locking tongue sleeve on one side of the positioning ring ridge; positioning grooves are provided on the locking tongue sleeve on both sides of the locking through holes.

[0013] The inner wall of the locking tongue ring is symmetrically provided with two sets of avoidance concave surfaces; the avoidance concave surfaces are connected to each other by extrusion surfaces; the avoidance concave surfaces and the extrusion surfaces are connected by a rounded transition.

[0014] The locking tongue has an integrated structure, which includes a snap-fit ​​body, an elastic plate, and a positioning rod; the snap-fit ​​body has elastic plates symmetrically arranged at both ends; the elastic plate has a positioning rod at its end; and the snap-fit ​​body and the elastic plate form an arc-shaped structure.

[0015] A positioning ring plate is provided on the circumferential surface of the connecting elbow; two sets of sealing ring ridges are provided at intervals on the circumferential surface of the connecting elbow on one side of the positioning ring plate; two sets of slots are symmetrically provided between the sealing ring ridges through partition ridges.

[0016] The advantages of this invention compared to the prior art are as follows:

[0017] This positive-pressure power-driven air supply system, which isolates dust, toxic substances, and viruses, uses a power fan to deliver clean air, filtered by the filter components, through a flexible air supply hose into a fan-shaped duct. The air is then directed towards the wearer's face, quickly removing exhaled heat and preventing fogging of the viewing window on the airtight cover, thus providing the wearer with a clear view. This positive-pressure power-driven air supply system is compact and ingeniously designed. Assembly is simple: just insert the connecting elbow into the locking tongue sleeve and tighten the locking tongue ring. This operation greatly reduces assembly time. Furthermore, after assembly, the locking tongue automatically locks under the action of the spring, avoiding the safety hazards caused by loosening common in existing quick-connect fittings. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the present invention worn on the human body;

[0019] Figure 2 This is a three-dimensional structural diagram of the protective headgear in this invention with the airtight fabric cover and viewing window removed.

[0020] Figure 3 This is a three-dimensional structural diagram of the fan-shaped air duct in this invention;

[0021] Figure 4 This is a three-dimensional structural diagram of the assembly of the gas delivery hose, quick-connect fitting, and fan connector in this invention;

[0022] Figure 5 This is an exploded structural diagram of the quick-connect pipe fitting in this invention;

[0023] Figure 6 This is a schematic diagram of the connecting elbow in this invention;

[0024] Figure 7 This is a schematic diagram of the locking tongue sleeve in this invention;

[0025] Figure 8 This is a schematic diagram of the locking tongue ring in this invention;

[0026] Figure 9 This is a schematic cross-sectional view of the locking tongue ring in this invention;

[0027] Figure 10 This is a schematic diagram of the locking tongue in this invention;

[0028] Figure 11 This is a schematic diagram of the assembled quick-connect pipe fitting in this invention;

[0029] Figure 12 for Figure 11Schematic diagram of the structure in the AA direction;

[0030] Figure 13 for Figure 12 Enlarged structural diagram at point C;

[0031] Figure 14 for Figure 11 A schematic diagram of the structure when the middle BB direction is in the locked state;

[0032] Figure 15 for Figure 11 A schematic diagram of the structure when the middle BB direction is in the loosened state;

[0033] Figure 16 This is a schematic diagram of the structure of the power blower in this invention;

[0034] Figure 17 This is an exploded structural diagram of the power blower in this invention;

[0035] Figure 18 This is an exploded view of the secondary filter element in this invention;

[0036] Figure 19 This is a rear view of the primary filter element in this invention;

[0037] Figure 20 This is an exploded structural diagram of the primary filter element in this invention.

[0038] In the diagram: 1. Fan-shaped air duct; 2. Air supply hose; 3. Headgear body; 4. Airtight fabric cover; 5. Viewing window; 6. Adjustable headband; 7. Locking sleeve; 8. Locking tongue sleeve; 9. Locking tongue ring; 10. Locking tongue; 11. Connecting elbow; 12. External thread; 13. Pressing edge; 14. Positioning ring ridge; 15. Snap-fit ​​hole; 16. Positioning groove; 17. Avoidance concave surface; 18. Extrusion surface; 19. Snap-fit ​​body; 20. Elastic plate; 21. Positioning rod; 22. Positioning ring plate; 23. Sealing ring ridge; 24. Snap-fit ​​groove; 25. Lock 26. Pipe nut; 27. Clip-on connector; 28. Fan housing; 29. ​​Battery; 30. Outer cover; 31. Fan rear cover; 32. Air outlet; 33. Air inlet; 34. Centrifugal fan; 35. Assembly frame; 36. Secondary filter element; 37. Frame cover; 38. Air inlet pipe; 39. Assembly block; 40. Filter element sealing ring; 41. Assembly through hole; 42. Clip; 43. Assembly box; 44. Primary filter element; 45. Assembly hoop; 46. Filter gasket; 47. Assembly groove; 48. Limiting groove; 49. Sealing ring. Detailed Implementation

[0039] As attached Figure 1-20 As shown

[0040] The positive pressure power supply air system for isolating dust, toxic substances, and viruses includes a protective hood, a fan-shaped air duct 1, an air supply hose 2, a quick-connect fitting, and a power supply fan. The protective hood includes a hood body 3, an airtight fabric cover 4, a viewing window 5, and an adjustable headband 6. The airtight fabric cover 4 is completely fitted over the hood body 3. A viewing window 5 is provided on the front end of the airtight fabric cover 4. An elastic band is installed at the bottom of the airtight fabric cover 4. In use, the elastic band is fastened to the lining of the wearer's isolation suit, thereby forming a sealed space between the entire protective hood and the wearer's isolation suit.

[0041] The headgear body 3 is equipped with an adjustable headband 6, which is existing technology. The adjustable headband 6 includes a headband rack, a rack groove, a gear, and an adjustment knob. The gear meshes with the headband rack. When in use, the adjustment knob drives the gear to rotate. By rotating the gear, the rack slides, thereby adjusting the tightness of the headband 6, thus adapting to wearers with different head diameters.

[0042] A fan-shaped air duct 1 is provided on the inner side of the top of the main body 3 of the protective headgear. The fan-shaped air duct 1 is located inside the airtight cloth cover 4. One end of the fan-shaped air duct 1 extends to the front of the inner side of the protective headgear. An air outlet 40 is provided on the fan-shaped air duct 1 extending to the front of the inner side of the protective headgear. The air outlet 40 is located above the front of the wearer's face. The other end of the fan-shaped air duct 1 extends to the rear of the inner side of the protective headgear. The interface end of the fan-shaped air duct 1 extending to the rear of the inner side of the protective headgear passes through the airtight cloth cover 4. The interface end of the fan-shaped air duct 1 is sealed and connected to the airtight cloth cover 4 at the connection point.

[0043] The interface end 41 of the fan-shaped air duct 1 is equipped with an air supply hose 2 via a quick-connect fitting. The air supply hose 2 is connected to the protective headgear. The quick-connect fitting includes a connecting elbow 11, a locking tongue sleeve 8, a locking tongue ring 9, a locking tongue 10, and a locking sleeve 7. The locking sleeve 7 has an internal thread. The air supply hose 2 is a corrugated pipe or a regular hose. When the air supply hose 2 is a corrugated pipe, it can maintain a threaded connection with the locking sleeve 7. When the air supply hose 2 is a regular hose, one end of it can be inserted into the inside of the locking sleeve 7.

[0044] The upper end of the locking sleeve 7 is threadedly connected to the locking tongue sleeve 8, which has a "stepped structure"; the circumferential surface of the thin section of the locking tongue sleeve 8 is provided with external threads 12; during assembly, the locking tongue sleeve 8 can maintain a threaded connection with the locking sleeve 7 through the external threads 12.

[0045] The locking tongue sleeve 8 below the external thread 12 is provided with a tapered clamping edge 13. The purpose of providing the clamping edge 13 is to allow the clamping edge 13 of the locking tongue sleeve 8 to be inserted into the interior of one end of the gas delivery hose 2 during assembly. When the locking tongue sleeve 8 is tightened, the clamping edge 13 can clamp and fix the gas delivery hose 2 with the cooperation of the locking sleeve 7.

[0046] A positioning ring ridge 14 is provided on the circumferential surface of the thick section of the locking tongue sleeve 8; a locking through hole 15 is symmetrically provided on the circumferential surface of the locking tongue sleeve 8 on one side of the positioning ring ridge 14; a positioning groove 16 is provided on the locking tongue sleeve 8 on both sides of the locking through hole 15.

[0047] The latch sleeve 8 is fitted with a latch 10 through a snap-fit ​​hole 15 and a positioning groove 16. The latch 10 has an integral structure, which includes a snap-fit ​​body 19, an elastic plate 20 and a positioning rod 21. The snap-fit ​​body 19 has elastic plates 20 symmetrically arranged at both ends. The positioning rod 21 is arranged at the end of the elastic plate 20. An arc-shaped structure is formed between the snap-fit ​​body 19 and the elastic plate 20.

[0048] The positioning rod 21 of the locking tongue 10 is slidably connected to the positioning groove 16; when the locking tongue 10 is pressed, under the limitation of the positioning groove 16, the locking tongue 10 and the locking body 19 will overcome the elastic force of the elastic plate 20 and move inward through the locking hole 15.

[0049] A locking tongue ring 9 is fitted on the locking tongue sleeve 8 at the upper end of the locking tube sleeve 7. Under the action of the end face of the locking tube sleeve 7 and the positioning ring ridge 14, the locking tongue ring 9 can only rotate and cannot undergo other displacement movements, thus avoiding the problem of the locking tongue ring 9 disengaging from the working position.

[0050] The inner wall of the locking tongue ring 9 is symmetrically provided with two sets of clearance concave surfaces 17; the clearance concave surfaces 17 are connected to each other by the extrusion surface 18; the clearance concave surfaces 17 and the extrusion surface 18 are connected by an arc transition; the purpose of the locking tongue ring 9 in this way is to enable the locking tongue 10 to be squeezed by the extrusion surface 18 during operation so that it will deform.

[0051] A connecting elbow 11 is inserted into the upper end of the locking tongue sleeve 8, and the connecting elbow 11 is sealed and snapped into the fan-shaped air duct 1.

[0052] A positioning ring plate 22 is provided on the circumferential surface of the connecting elbow 11. During assembly, when the connecting elbow 11 is inserted into the locking tongue sleeve 8, the positioning ring plate 22 can limit the insertion position of the connecting elbow 11, thereby avoiding the problem of inaccurate insertion position during assembly.

[0053] Two sets of sealing ring ridges 23 are spaced apart on the circumferential surface of the connecting elbow 11 on one side of the positioning ring plate 22. After the connecting elbow 11 is inserted into the locking tongue sleeve 8, the sealing ring ridges 23 can be sealed to the inner wall of the locking tongue sleeve 8. This solves the problem of leakage caused by gaps between the connecting elbow 11 and the locking tongue sleeve 8 during operation.

[0054] Two sets of slots 24 are symmetrically arranged between the sealing ring ridges 23 through the partition ridges. The purpose of setting the slots 24 is to allow the locking tongue 10 to deform during assembly, and the locking body 19 to pass through the locking hole 15 on the locking tongue sleeve 8 and be inserted into the slot 24, thereby achieving the purpose of keeping the connecting elbow 11 fixedly connected to the locking tongue sleeve 8 through the locking tongue 10.

[0055] The other end of the gas delivery hose 2 is connected to the power blower through a blower connector. The blower connector includes a locking nut 25 and a clamping connector 26. The clamping connector 26 is fitted onto the other end of the gas delivery hose 2. The locking nut 25 is fitted onto the outside of the gas delivery hose 2. The clamping connector 26 is threadedly connected to the locking nut 25. The locking nut 25 and the clamping connector 26 form a seal and clamp the other end of the gas delivery hose 2. The clamping connector 26 is sealed and clamped to the power blower. The power blower is connected to the gas delivery hose 2.

[0056] The positive pressure ventilation system for isolating dust, toxic substances, and viruses includes a fan housing 27, a battery 28, a filter assembly, and a fan rear cover 30. The fan rear cover 30 is clipped onto the back of the fan housing 27. An air outlet 31 is provided at the top of the fan housing 27. The air outlet 31 is connected to the clip-on connector 26 by locking teeth and locking grooves. The battery 28 is clipped onto the bottom of the fan housing 27. Air inlets 32 are symmetrically arranged on the front of the fan housing 27. A centrifugal fan 33 is mounted in the air inlet 32 ​​by a mounting bracket. The centrifugal fan 33 is electrically connected to the battery 28, and the battery 28 provides power to the centrifugal fan 33.

[0057] A filter assembly is installed on the fan housing 27 at the front end of the air inlet 32. The filter assembly includes a secondary filter element, a primary filter element, and an outer cover 29. The outer cover 29 is fastened to the fan housing 27 of the power blower. A secondary filter element is provided between the fan housing 27 and the outer cover 29. A primary filter element is installed on the surface of the outer cover 29. The primary filter element is connected to the power blower through the secondary filter element.

[0058] The secondary filter element consists of an assembly frame 34, a secondary filter element 35, and a frame cover 36. The assembly frame 34 is a box-shaped body, and the frame cover 36 is movably attached to the assembly frame 34 by a latch. The secondary filter element 35 is a dustproof filter element made of nano-electrostatic fiber and is grid-shaped. An air inlet hole is provided on the assembly frame 34 corresponding to the air inlet 32, and a sealing ring 48 is provided between the air inlet hole and the air inlet 32. An air inlet pipe 37 is provided on the frame cover 36 corresponding to the air inlet hole. During assembly, the air inlet pipe 37 passes through the assembly hole 40 to fix the secondary filter element between the power blower and the outer cover 29. The air inlet pipe 37 is a variable diameter pipe, and three assembly blocks 38 are arranged at an angle on the outer circumference of the small diameter end of the air inlet pipe 37.

[0059] The air inlet pipe 37 on the surface of the outer cover 29 is equipped with a primary filter element. The primary filter element consists of an assembly box 42, a primary filter element 43, a filter pad 45, and an assembly ring 44. The primary filter element 43 is installed in the assembly box 42 through the filter pad 45. Depending on the environment, the primary filter element 43 is a dust filter or a gas filter. The assembly box 42 is provided with an assembly ring 44. The assembly ring 44 is connected to the primary filter element 43 through the filter pad 45. The end face of the assembly ring 44 is irregularly round to fix the primary filter element 43 and the filter pad 45 in the assembly box 42.

[0060] Assembly slots are provided on the inner walls of both sides of the assembly hoop 44. Assembly blocks are provided on both sides of the assembly box 42 corresponding to the assembly slots. The assembly box 42 and the assembly hoop 44 are engaged by the assembly blocks and the assembly slots. An assembly groove 46 is formed on the assembly box 42 between the assembly blocks. A retaining ring is provided at the end of the assembly groove 46. A limiting groove 47 corresponding to the assembly block 38 is provided on the retaining ring. An anti-rotation rib is provided on the assembly groove 46 on one side of the limiting groove 47. During installation, the assembly block 38 and the limiting groove are engaged. With the assembly of 47, the small-diameter end of the air inlet pipe 37 is inserted into the assembly slot 46. Then, the primary filter element is rotated so that the anti-rotation rib abuts against the assembly block 38, indicating that the primary filter element is installed. At the same time, the installation of the primary filter element through the assembly block 38 and the limiting slot 47 facilitates the replacement of the primary filter element according to different environments. The primary filter element is connected to the power blower through the air inlet pipe 37, so that the outside air is discharged from the air outlet 31 of the power blower after being filtered by the primary and secondary filter elements.

[0061] The positive pressure ventilation system, which isolates dust and viruses, has a wind pressure sensor (model XGZP6897D) installed at the air outlet 31 of the power supply fan. The power supply fan has a built-in programmable controller (model GD32F130C8T6). When the wind pressure sensor detects that the wind pressure is lower than the set value, the wind pressure sensor transmits the detected signal to the programmable controller, which increases the speed of the centrifugal fan 33. When the wind pressure sensor detects that the wind pressure is higher than the set value, the wind pressure sensor transmits the detected signal to the programmable controller, which decreases the speed of the centrifugal fan 33, thereby keeping the wind pressure at the air outlet 31 stable at the set value.

[0062] When using this positive pressure power supply ventilation system that isolates dust, toxic substances, and viruses, the wearer first mates with the end of the air supply hose 2 with the fan connector and seals it with the air outlet 31 of the power supply fan. Then, the upper end of the connecting elbow 11 is mates with the interface end of the fan-shaped air duct 1 of the protective headgear. After the lower end of the connecting elbow 11 is inserted into the locking tongue sleeve 8, the locking tongue ring 9 is rotated to squeeze the locking tongue 10 through the compression surface 18. This allows the locking body 19 of the locking tongue 10 to pass through the locking through hole 15 on the locking tongue sleeve 8 and be inserted into the slot 24. This achieves the purpose of keeping the connecting elbow 11 fixedly connected to the locking tongue sleeve 8 through the locking tongue 10. In this way, the quick-connect fitting is assembled and connected.

[0063] The wearer places the protective hood on their head, adjusts the headband 6 to a suitable size, and secures the elastic band at the bottom of the airtight fabric cover 4 to the lining of the wearer's protective suit. The powered air supply fan is then attached to the waist via a belt or buckle. The fan is turned on, drawing in outside air that has been filtered through the filter assembly and then blown onto the wearer's face through the air hose 2 and the fan-shaped air duct 1's nozzle 40. This effectively dissipates heat from inside the protective hood while preventing fogging of the viewing window 5, ensuring the wearer breathes clean air without experiencing breathing difficulties.

[0064] When it is necessary to loosen the quick-release pipe fitting, rotate the locking tongue ring 9 so that the clearance concave surface 17 corresponds to the locking tongue 10. At this time, the locking tongue 10 will reset under its own elastic force. After the locking tongue 10 resets, it will disengage from the connecting elbow 11. Then, pull the connecting elbow 11 out from the inside of the locking tongue sleeve 8 to complete the loosening action of the pipe fitting.

[0065] This positive pressure power supply air system, which isolates dust, toxic substances, and viruses, has a compact structure and ingenious design. Assembly is simple: just insert the connecting elbow 11 into the locking tongue sleeve 8 and tighten the locking tongue ring 9. This operation greatly reduces assembly time. Furthermore, after assembly, the locking tongue 10 automatically locks under elastic force, avoiding the safety hazards caused by loosening common in existing pipe joints. This makes it particularly suitable for head-mounted filtration air supply devices.

[0066] The above description is merely a preferred embodiment of the present invention. The above examples do not limit the substantive content of the present invention in any way. Any simple modifications or variations made by those skilled in the art to the above specific embodiments based on the technical essence of the present invention after reading this specification, as well as equivalent embodiments that may be changed or modified using the disclosed technical content, shall still fall within the scope of the technical solution of the present invention and shall not depart from the essence and scope of the present invention.

Claims

1. A positive pressure power supply ventilation system for isolating dust and toxic substances and viruses, comprising a protective hood, a fan-shaped duct (1), a flexible air supply hose (2), a quick-connect fitting, and a power supply fan, characterized in that: A fan-shaped air duct (1) is provided inside the protective head cover. One end of the fan-shaped air duct (1) extends to the front of the inside of the protective head cover, and the other end of the fan-shaped air duct (1) extends to the rear of the inside of the protective head cover. A gas delivery hose (2) is installed on the fan-shaped air duct (1) extending to the rear of the inside of the protective head cover through a quick pipe connector. The gas delivery hose (2) is connected to the protective head cover. The other end of the gas delivery hose (2) is connected to the power blower through a blower connector. The power blower is connected to the gas delivery hose (2). The quick-connect fitting includes a connecting elbow (11), a locking tongue sleeve (8), a locking tongue ring (9), a locking tongue (10), and a locking sleeve (7). The upper end of the locking sleeve (7) is threaded with a locking tongue sleeve (8), and the locking sleeve (7) has an internal thread. A locking tongue ring (9) is fitted on the locking tongue sleeve (8) at the upper end of the locking sleeve (7). Two sets of locking tongues (10) are symmetrically fitted on the locking tongue sleeve (8) inside the locking tongue ring (9). A connecting elbow (11) is inserted into the upper end of the locking tongue sleeve (8). The locking tongue (10) and the connecting elbow (11) are intermittently connected by a locking mechanism, and the connecting elbow (11) is sealed and connected by a locking mechanism to the fan-shaped air duct (1). The locking tongue sleeve (8) has a "stepped structure"; the circumferential surface of the thin section of the locking tongue sleeve (8) is provided with an external thread (12); the port of the locking tongue sleeve (8) below the external thread (12) is provided with a "conical" pressing edge (13); the circumferential surface of the thick section of the locking tongue sleeve (8) is provided with a positioning ring ridge (14); the circumferential surface of the locking tongue sleeve (8) on one side of the positioning ring ridge (14) is symmetrically provided with snap-fit ​​through holes (15); the locking tongue sleeve (8) on both sides of the snap-fit ​​through holes (15) is provided with positioning grooves (16); The inner wall of the locking tongue ring (9) is symmetrically provided with two sets of clearance concave surfaces (17); the clearance concave surfaces (17) are connected to each other through the extrusion surface (18); the clearance concave surfaces (17) and the extrusion surface (18) are connected by a rounded transition; The locking tongue (10) is an integral structure, which includes a snap-fit ​​body (19), an elastic plate (20) and a positioning rod (21); the snap-fit ​​body (19) has elastic plates (20) symmetrically arranged at both ends; the elastic plate (20) has a positioning rod (21) at the end; the snap-fit ​​body (19) and the elastic plate (20) form an arc-shaped structure.

2. The positive pressure ventilation system for isolating dust and toxic substances and viruses according to claim 1, characterized in that: The protective headgear includes a headgear body (3), an airtight cloth cover (4), a viewing window (5), and an adjustable headband (6). The headgear body (3) is covered with an airtight cloth cover (4), and the airtight cloth cover (4) is provided with a viewing window (5). The bottom of the airtight cloth cover (4) is equipped with an elastic band, and the headgear body (3) is provided with an adjustable headband (6).

3. The positive pressure ventilation system for isolating dust and toxic substances and viruses according to claim 1, characterized in that: The power blower includes a blower housing (27), a battery (28), a filter assembly, and a blower rear cover (30). The top of the blower housing (27) is provided with an air outlet (31), and the bottom of the blower housing (27) is fitted with a battery (28). The front of the blower housing (27) is symmetrically provided with air inlets (32), and a centrifugal fan (33) is installed inside the air inlet (32). The centrifugal fan (33) is electrically connected to the battery (28). The front end of the air inlet (32) is fitted with a filter assembly on the blower housing (27), and the back of the blower housing (27) is fitted with a blower rear cover (30).

4. The positive pressure ventilation system for isolating dust and toxic substances and viruses according to claim 3, characterized in that: The filter assembly includes a secondary filter element, a primary filter element and an outer cover (29). The outer cover (29) is fastened to the power blower. A secondary filter element is provided between the power blower and the outer cover (29). A primary filter element is installed on the surface of the outer cover (29). The primary filter element is connected to the power blower through the secondary filter element.

5. The positive pressure ventilation system for isolating dust and toxic substances and viruses according to claim 3, characterized in that: The front end of the fan housing (27) is provided with a locking hook. An unlocking switch is movably installed on the fan housing (27) behind one of the locking hooks. A locking tooth is provided on the protective shell corresponding to the locking hook. The locking tooth and the locking hook are engaged and locked. The locking tooth and the unlocking switch are intermittently connected.

6. The positive pressure ventilation system for isolating dust and toxic substances and viruses according to claim 1, characterized in that: A positioning ring plate (22) is provided on the circumferential surface of the connecting elbow (11); two sets of sealing ring ribs (23) are provided at intervals on the circumferential surface of the connecting elbow (11) on one side of the positioning ring plate (22); two sets of slots (24) are symmetrically provided between the sealing ring ribs (23) through partition ribs.

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