1.主排氣管的通風面積不夠。

1. The ventilation area of the main exhaust pipe is insufficient.

根據工程經驗，主管道風速不能超過 15m/s，否則在運行一段時間后很容易使排煙系統通暢。在油煙凈化器的運行實踐中，大部分情況是由于排氣管通風面積不足所致，管道內氣體流量在 15m/ s 以上。

According to engineering experience, the wind speed of the main pipeline cannot exceed 15m/s, otherwise it is easy to make the smoke exhaust system unobstructed after running for a period of time. In the operation practice of oil fume purifiers, most cases are caused by insufficient ventilation area of the exhaust pipe, and the gas flow rate in the pipeline is above 15m/s.

2.管道的橫截面面積變小

2. The cross-sectional area of the pipeline decreases

由于需要通過建筑橫梁，管道的通風截面面積變小，截面上的阻力增大，導致氣流不順暢。

Due to the need to pass through the building crossbeam, the ventilation cross-sectional area of the pipeline decreases, and the resistance on the cross-section increases, resulting in uneven airflow.

3.使用排水管后集料的積聚

3. Accumulation of aggregates after using drainage pipes

當排煙管通過建筑物橫梁或避開其他設備管道時，排煙管的某一部分將低于排煙管的整體水平。使用一段時間后，由于油水混合物將積聚在排氣管的下部，排煙將受到直接影響。

When smoke exhaust pipes pass through building beams or avoid other equipment pipelines, a certain part of the smoke exhaust pipe will be lower than the overall level of the smoke exhaust pipe. After a period of use, due to the accumulation of oil-water mixture in the lower part of the exhaust pipe, smoke exhaust will be directly affected.

4.低排煙不平坦

4. Uneven low smoke exhaust

不同樓層的廚房煙氣通過同一主管道排出，廚房出口附近的廚房排煙效果較好，但下樓廚房的排煙不順暢。

Kitchen smoke from different floors is discharged through the same main pipeline. The kitchen near the kitchen outlet has a better smoke exhaust effect, but the smoke exhaust from the downstairs kitchen is not smooth.

5.建議安裝排煙風扇

5. It is recommended to install a smoke exhaust fan

對于大排煙的廚房，還建議安裝排煙風扇。有三種排煙風扇：軸流風扇、空氣底盤和離心風扇。

For kitchens with high smoke exhaust, it is also recommended to install smoke exhaust fans. There are three types of smoke exhaust fans: axial fans, air chassis, and centrifugal fans.

一般情況來講，通風管道在安裝過程當中提前設計好當前廚房的規劃，從而減少通風管道出現的排煙不正常狀況

Generally speaking, ventilation ducts should be designed in advance during the installation process to minimize the occurrence of abnormal smoke exhaust in the kitchen