Speaking of tunnel lovers, I think many people are different from ordinary lovers. Those are only set in large size tunnels. But in fact, they have a big difference, that is, they can be opposite. Generally speaking, tunnel fans cannot be reversed. Once it is reversed, it means that fans have shortcomings. However, the fan of the tunnel must have the function of flipping and flipping. for what?

1. Provide fresh air to the front (to the inside).

2. Inverse (outer) and ventilation effects.

Generally, tunnel fans supply air inwards, but in special cases they must exhaust air outwards. Generally speaking, the horizontal air valve is opened in normal times, the vertical air valve is opened in a fire, and there is a special emergency fan for emergency situations.

Therefore, the tunnel fan should have the function of positive and negative reversal, so that the tunnel fan can run normally and send fresh and fresh air into the tunnel. Once a dangerous accident occurs, it will immediately reverse the state of the risky situation, and the danger can be effectively eliminated. and closing tunnel personnel. low risk.