Installation, maintenance and change of air duct of smoke exhaust fan in Shenzhen catering kitchen
Determination of kitchen exhaust volume: Professional undertaking of ventilation and smoke exhaust project of white iron, kitchen smoke exhaust of many restaurants, and Shenzhen Hunan University bowl The restaurant chain stores are all made by us, and the ventilation and smoke exhaust effect is good!
The exhaust air volume shall be determined according to the size of the kitchen, the number of stoves, the size of the hood, and the emission of pollutants. Generally, there are several methods to determine the exhaust air volume of the kitchen:
(1) Determine the exhaust air volume according to the air exchange rate:
Each kitchen is quite different, and the kitchen area is the same as Kitchenware The number of stoves is not proportional, and the pollutants and heat generated by the stoves are also
There is a big difference. In fact, kitchen ventilation is not integrated ventilation, and there will be a big error in designing air volume according to air exchange rate.
(2) The exhaust air volume is designed according to the amount of pollutant emission:
The national environmental protection GB18483-2001 Emission Standard of Cooking Fume stipulates that the air demand of each stove is 2000m3/h. The author believes that there are still limitations in designing air volume according to this method. In fact, the actual situation of the catering industry is complicated: the size of the stove is different from that of the Cantonese style and the Soviet style; In addition to the stove, there are soup pots, casseroles, steamer ovens, etc; In terms of function, there are cooking rooms, steaming and boiling rooms, pastry rooms, barbecue rooms, western food processing rooms, dishwashing rooms, etc. The heat dissipation and pollutant emission are different. It is inappropriate to simply determine the exhaust air volume according to the number of stoves.
(3) The air volume is determined by the size of the hood:
It is appropriate to calculate the air volume by the product of the air inlet area and air inlet speed between the lower edge of the hood and the stove. The exhaust air volume can be calculated according to the following formula:
G=3600L（h2-h1）Vx，m3/h
L ----- length of the air inlet surface under the hood (the length of both ends of the hood and the length of the other side of the double side air inlet shall also be included), m;
H1 ---- height of hearth, m;
H2 ----- height of lower edge of smoke hood, m;
Vx ----- air inlet speed, m/s.
The height of the stove is calculated as 0.8 m, and the height of the lower edge of the hood is generally calculated as 1.9 m. The air inlet speed is about 0.5 m/s. A large number of practices have proved that the air inlet surface of the smoke collection hood is about 2000 m3/h per meter, which has an ideal ventilation effect. The hood should be as close as possible Wallcovering To reduce the air inlet area and avoid excessive air volume.
The kitchen exhaust should avoid a lot of air conditioner The air in the space is pumped out. It needs to be avoided by natural air supplement and mechanical air supplement. Whether it is natural air supplement or mechanical air supplement, the path of fresh air shall be considered to avoid dead zone, so as to facilitate the exhaust of indoor polluted air. Mechanical air make-up shall be conducted through air ducts and air supply outlets. The pipeline system shall not be complicated, and excessive local wind speed shall be avoided. The amount of fresh air supplement should be 70% - 80% of the exhaust air volume.
Since the air exchange rate in the kitchen is large, the air conditioning in the kitchen has no effect. By extracting a small amount of air conditioning from the lobby and directly putting the chef in the wind bath in the form of nozzle, the bad working environment caused by the high temperature in the kitchen in summer and the baking of the stove can be improved;
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