Basic design principle of tunnel fan ventilation
1. Tunnel jet fan ventilation system
Tunnel driving face must adopt independent ventilation, no series ventilation between any two working face. The air volume required by the tunnel shall be calculated according to the smoke exhaust from blasting, the majority of working at the same time and the construction machinery respectively, and detected according to the allowable wind speed, using the large value among them. Continuous ventilation should be implemented during tunnel construction. In case of shutdown due to maintenance, power failure and other reasons, personnel must be withdrawn and power supply must be cut off.
2. Tunnel jet fan ventilation equipment
pressure type fan must be installed outside the hole, to avoid pollution air circulation. The fan should be equipped with two power supplies and wind power locking device. When one power supply stops, the other one should be connected within 15 minutes to ensure the normal operation of the fan.
A set of standby fans with the same performance must be kept in good condition.
the tunnel should use antistatic, flame retardant wind belt. The distance of the excavated surface of the wind belt mouth should be less than 20m.
3. ventilation pipe layout
Auxiliary adit ventilation pipe is arranged in the auxiliary adit vault, connected with the main fan outside the hole, and the tunnel fan is fixed on the fan door frame set outside the entrance of the auxiliary adit.
The door frame of the tunnel axial fan adopts I16 I-steel, which is composed of three to four trusses of arch frames.
the door frame longitudinal use channel steel connection firm, if necessary can increase the diagonal support.
The base of fan frame is made of C20 concrete. The size of the base top should ensure that the fan distribution cabinet and awning can be installed.
Adjust the size of fan base and fan frame according to the tunnel situation.