In the excavation work, because there is no circular network, there is only one passage in the roadway called single head. It needs to enter the wind and wind, and dust and gun smoke will be generated during the excavation process. Therefore, without effective ventilation, It is difficult to ensure the safety of production. Therefore, the special ventilation measures taken in this area are called local ventilation. Local ventilation methods are: First, use local fan fan ventilation; 2. Using a high-speed jet of compressed air or high-pressure water to drive the ejector of the surrounding air for local ventilation; 3. Using the total pressure difference of the mine and guiding the airflow with the air duct and the wind wall for local ventilation; 4. Drilling and ventilation. After drilling through the upper and middle sections, use the total pressure difference or local fan ventilation. Large area essential oil aroma diffuser machine for big space, industrial scent diffuser for shopping mall, commercial building air port use metal HVAC scent machine with big capacity 1000ml, 5000ml bottle, work with air condition or land standing, coverage 5000 CBM, 7000 cubic meter, with timer mobile App smart control. Big Area Diffuser Machine,Commercial Diffuser Machine,Scent Machine,Scent Diffuser Machine Guangzhou Tang Mei Environmental Protection Technology Co.,Ltd , https://www.tonemys.com