<\/span><\/h2>\nDifferent from the natural ventilation\u00a0 <\/span>system, the local ventilation system<\/span><\/b> \u00a0includes dust collectors at the dust emission sources (crushers, grinders, mixers, sieves, buckets, on conveyor terminals), pipelines, etc. corrugated iron guide, dust filter equipment and exhaust fan. This is a type of forced ventilation system used to ventilate a small area.<\/span><\/p>\nUsing Local Ventilation System helps to ensure worker’s health. There are two commonly used types of local ventilation systems: local dust extraction systems and local toxic gas extraction systems.<\/span><\/p>\nWhat is local ventilation?<\/span><\/figcaption><\/figure>\n<\/span>Principles for effective local ventilation<\/span><\/span><\/h2>\nThe following principles should be ensured for good pollutant capture with high efficiency:<\/span><\/p>\n\u2013 Capture as close to the source of pollutant discharge as possible.<\/span><\/p>\n\u2013 The air intake is as close to the pollutant discharge source as possible.<\/span><\/p>\n\u2013 The speed of collecting dust or toxic gas must be large enough to absorb all emitted pollutants.<\/span><\/p>\n\u2013 Pollutants catching mouths must not interfere with technological activities<\/span><\/p>\n\u2013 Contaminated air entering the suction cup must not pass through the respiratory zone of the operator<\/span><\/p>\n<\/span>Classification of local ventilation duct systems<\/span><\/span><\/h2>\nWith the superiority and convenience, the ventilation duct system has been divided into many types depending on the purpose and usage situation.<\/span><\/p>\n<\/span><\/span>1. Follow the direction of wind movement<\/span><\/span><\/h3>\n\u2013 Blower type ventilation:<\/span><\/strong> \u00a0Blows clean air into the interior space through openings thanks to the differential pressure. The advantage of this method is that it can supply wind and clean air into the room, where there are many people or excess heat, but the disadvantage of this method is that the pressure in the room is positive, so the wind spreads in all directions. even unwanted places.<\/span><\/p>\n\u2013 Suction ventilation:<\/span><\/strong> \u00a0Exhaust contaminated air from the room and outside air enters the room through openings or fresh air intakes thanks to the difference in pressure. This method has the advantage of being able to directly absorb the polluted air in the space, preventing it from spreading around. However, the disadvantage of this method is that the circulation in the room is very low, almost non-existent. On the other hand, the air entering the room is free, uncontrolled.<\/span><\/p>\n\u2013 Combined ventilation:<\/span><\/strong> \u00a0Combining both blowing clean air into the space and sucking out the stuffy air, this is an effective method. Ventilation combines exhaust and blow, including exhaust fan and blower system. This method is a combination of the advantages of the above two methods. However, it requires higher investment costs.<\/span><\/p>\n<\/span><\/span>2. According to the method of organization<\/span><\/span><\/h3>\n\u2013 General ventilation:<\/span><\/strong> \u00a0Overall ventilation for the entire room or building<\/span><\/p>\n\u2013 Local ventilation:<\/span><\/strong> \u00a0Ventilate a designated area or rooms containing a lot of hazardous waste.<\/span><\/p>\n<\/span><\/span>3. According to the dynamics of creating ventilation<\/span><\/span><\/h3>\n\u2013 Natural ventilation:<\/span><\/strong> \u00a0Is the exchange of air indoors and outdoors thanks to the difference in pressure. Usually the head is created due to the temperature difference between the outside and inside.<\/span><\/p>\n\u2013 Forced ventilation:<\/span><\/strong> \u00a0The ventilation process is done by external force ie using a fan.<\/span><\/p>\n<\/span><\/span>4. According to the purpose<\/span><\/span><\/h3>\n\u2013 Normal ventilation:<\/span><\/strong> \u00a0The purpose of the ventilation duct system is to remove harmful substances, excess heat, excess moisture and provide fresh clean air for human living space.<\/span><\/p>\n\u2013 Ventilation incidents:<\/span><\/strong> \u00a0Many buildings are equipped with ventilation duct systems to overcome problems that occur. <\/span>Prevention of chemical spills: When there are problems, the ventilation system works and releases toxic gases to predetermined places or to the outside.<\/span><\/p>\n\u2013 In case of fire:<\/span><\/strong> \u00a0To prevent fire from entering the stairs and exit doors, the air intake system works and creates positive pressure on these sections for people to escape easily.<\/span><\/p>\n