吸气式局部排风罩的防倒流装置
By designing anti-backflow components and filter components in the intake-type local exhaust hood, the problem of polluted air backflow when the fan is stopped is solved, achieving safe and efficient exhaust and convenient maintenance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG TIANYE INTELLIGENT TECH CO LTD
- Filing Date
- 2025-06-24
- Publication Date
- 2026-07-17
AI Technical Summary
When the fan stops running, the pressure imbalance inside and outside the exhaust duct of a traditional exhaust hood causes polluted air to flow back, resulting in secondary diffusion of pollutants, which threatens health and shortens the life of the equipment.
An anti-backflow device for a suction-type local exhaust hood was designed, including an anti-backflow component and a filter component. The device uses a conical cylinder, baffle and magnetic block to form an airflow channel when the fan is running. When the fan stops, the airflow channel is closed to prevent backflow, and particulate matter is intercepted by the filter screen.
It effectively prevents polluted air from flowing back, protects health, avoids equipment corrosion, improves ventilation efficiency, and facilitates maintenance.
Smart Images
Figure CN224507977U_ABST
Abstract
Claims
1. Anti-backflow device for an induced-draft local exhaust hood, comprising an exhaust duct (1) and a hood body (2), characterized in that, A fan is installed at the top inside the exhaust duct (1), an anti-backflow component (3) is installed inside the exhaust duct (1) and the anti-backflow component (3) is located below the fan, a filter component (4) is installed at the bottom of the anti-backflow component (3), the filter component (4) includes a fixing ring (401), and the cover (2) is installed at the bottom of the fixing ring (401); The anti-backflow component (3) includes a conical cylinder (301) which is narrower at the top and wider at the bottom. The surface of the conical cylinder (301) is tightly fitted to the inner wall of the exhaust duct (1). An installation ring (302) is fixedly sleeved on the surface of the conical cylinder (301). Columns (303) are fixedly connected to both sides of the top of the installation ring (302), and U-shaped frames (304) are fixedly connected to the opposite side of the two columns (303). Baffles (305) are rotatably connected inside the U-shaped frame (304), and the two baffles (305) are used in conjunction with the opening at the top of the conical cylinder (301).
2. The backdraft damper for an induced-draft local exhaust hood according to claim 1, wherein: The fixing ring (401) is located at the bottom of the exhaust duct (1) and the conical cylinder (301) is fixedly connected inside the fixing ring (401). A filter screen (402) is fixedly connected inside the fixing ring (401).
3. The anti-downwash device for an induced-draft local exhaust hood according to claim 1, wherein: The bottom of the exhaust duct (1) is provided with an annular groove (5). The bottom of the fixing ring (401) is fixedly connected with a connecting ring (403) and the connecting ring (403) cooperates with the annular groove (5). The interior of both sides of the exhaust duct (1) is threaded with fixing screws (6). Both sides of the surface of the connecting ring (403) are provided with threaded grooves (404) and the fixing screws (6) cooperate with the threaded grooves (404).
4. The anti-downwash device for an induced-draft local exhaust hood according to claim 3, wherein: The inner wall of the annular groove (5) is provided with a positioning groove (7), and the front and rear sides of the connecting ring (403) are provided with positioning blocks (405). The positioning groove (7) and the positioning blocks (405) are used in conjunction.
5. The anti-downwash device for an induced-draft local exhaust hood according to claim 1, wherein: The first magnetic block (8) is fixedly connected to the side of the column (303) and the baffle (305) that are close to each other, and the two first magnetic blocks (8) repel each other.
6. The anti-downwash device for an induced-draft local exhaust hood according to claim 1, wherein: A second magnetic block (9) is fixedly connected to the side of the baffle (305) near the bottom of the conical cylinder (301), and a metal block (10) is fixedly connected inside the top of the conical cylinder (301) and the metal block (10) is magnetically connected to the second magnetic block (9).
7. The anti-downwash device for an induced-draft local exhaust hood according to claim 1, wherein: The bottom of the fixing ring (401) is fixedly connected to a connecting cylinder (11), and the inner wall of the connecting cylinder (11) is provided with an internal thread.
8. The anti-downwash device for an induced-draft local exhaust hood according to claim 7, wherein: The top of the cover (2) is fixedly connected to the alignment cylinder (12), and the surface of the alignment cylinder (12) is provided with an external thread that is used to cooperate with the internal thread.