In order to ensure the purification effect, the smoke exhaust air volume is required to be calculated in strict accordance with the suction air speed of the exhaust hood in the actual design, and the suction air speed at the hood opening is generally not less than 0.5m/s. The minimum exhaust air volume is generally calculated by the following formula: L=2000PH
L - exhaust volume of exhaust hood, m3/h;
P - perimeter of the hood (excluding the side against the wall), m;
H - distance from hood opening to stove opening, m.
After calculating the exhaust air volume with the above formula, calculate the air suction speed at the hood according to the hood area to ensure that the air suction speed at the hood is not less than 0.5m/s.
In actual engineering design, estimation method is often used. According to the regulations on kitchen ventilation in Technical Measures for HVAC Design of Civil Buildings, kitchen ventilation can also be determined according to the following ventilation times:
Chinese kitchen: L=40-50 (times/h);
Western food kitchen: L=30-40 (times/h);
Staff canteen: L=25-35 (times/h).
As the layout of the building where the kitchen is located and the position of the kitchen in the building are different, conditional kitchens should be supplied with air orderly by the central air conditioning system of the building. However, most of the situations encountered at present are that the building does not have a kitchen air supply system. Many buildings with restaurants, kitchens, etc. are only designed with centralized heating system and no centralized air-conditioning system. When the kitchen is in working state, the exhaust system is put into operation, and the kitchen is in negative pressure state. The source of fresh air includes outdoor fresh air infiltration and a large amount of air in the dining room.
The horizontal section of the kitchen smoke exhaust pipe should not be too long. Generally, the maximum horizontal distance should not exceed 15m and should have a slope of more than 2%. A movable joint should be set at the horizontal end to facilitate the cleaning of oil dirt. The air exhaust speed shall not be less than 10m/s according to the specification to prevent oil from adhering to the flue due to low wind speed. The branch pipe connected to the exhaust hood shall be equipped with an air volume regulating valve.
Jinan smoke exhaust hood has been dedicated to the industry for many years. For more information about ventilation ducts, oil smoke purifiers and kitchen smoke exhaust schemes, please continue to pay attention to our website: http://www.jnqsg.com