What is the difference between a centrifugal fan and a negat

What is the difference between a centrifugal fan and a negative pressure fan?

Centrifugal fan is a machine that relies on input mechanical energy to increase gas pressure and discharge gas. It is a driven fluid machine.

The negative pressure fan uses the cooling principle of air convection and negative pressure ventilation. It is a kind of natural intake of fresh air from the opposite of the installation location --- the door or window, and the hot indoor air is quickly forced out of the outdoor. Any poor ventilation problems The all-improvable machine has a cooling effect of 90%-97%.

In terms of principle and product features:

The centrifugal fan is based on the principle of converting kinetic energy into potential energy, using a high-speed rotating impeller to accelerate the gas, then decelerate, change the flow direction, and convert the kinetic energy into potential energy (pressure). In a single-stage centrifugal fan, the gas enters the impeller from the axial direction, changes to the radial direction when the gas flows through the impeller, and then enters the diffuser. In the diffuser, the gas changes the direction of flow to form a deceleration. This deceleration effect converts kinetic energy into pressure energy. The increase in pressure mainly occurs in the impeller, followed by the expansion process. In a multi-stage centrifugal fan, a refluxer is used to make the air flow into the next impeller, resulting in higher pressure. The negative pressure fan adopts CAD/CAM planning for the whole machine, which has the characteristics of low investment cost, large air volume, low noise, low energy consumption, stable operation, long life and high power. The shutters automatically open and close to achieve dustproof, waterproof, beautiful and generous; It can be used for blowing or exhausting. It is the best choice for cooling and ventilation in modern workshops. Environmentally friendly and energy-saving negative pressure fans will become the mainstream of the ventilation and cooling equipment market.