White iron ventilation project is a general term for air supply, exhaust, dust removal and smoke exhaust system engineering.

Ventilation system design problems

1.1 Airflow organization:

The basic principle of the air flow organization of the white iron ventilation project is that the exhaust port should be as close as possible to the source of harmful substances or heat dissipation equipment, and the air supply port should be as close as possible to the operation site or the place where people often stay.

1.2 System resistance:

The ventilation duct is an important part of the ventilation system. The purpose of the ventilation duct system design is to reasonably organize the air flow in the white iron ventilation project. The initial investment and operating costs are the lowest overall. Theoretically speaking, the difference in resistance coefficient between the supply and exhaust ducts entering the civil shaft with and without the laminar flow plate can be up to 10 times. From the actual inspection of a project, it is found that the same type of fan is similar to the duct and the tuyere. , the air volume when used as air supply is 9780m3/h, and when used as exhaust air, the air volume is 6560m3/h, the difference is 22.7%. The selection of small tuyere is also a factor that increases the system resistance and reduces the air volume.

1.3 Fan selection:

According to the characteristic curve of the fan, it can be seen that the fan can work under various air volumes. At a certain working point of the characteristic curve, the wind pressure of the fan and the pressure in the system are balanced, and the air volume of the system is determined.

1.4 Fire damper setting: white iron ventilation project

The main purpose of setting the fire damper is to prevent the fire from spreading through the air duct. The author advocates the use of the “anti-backflow” measure of connecting the exhaust branch pipe of the bathroom to the exhaust shaft well and rising 60mm. It has the characteristics of simple structure, low cost and reliable operation. Because the elbow is used to enter the shaft, the branch pipe and the main pipe have the same airflow direction. The local resistance of this part is small, and the total resistance of the shaft exhaust is not necessarily increased due to the reduction of the shaft area.