Both the centrifugal fan and the negative pressure fan belong to the fluid conveying equipment, but they are different in the working principle and the product characteristics. Centrifugal fan is a kind of driven fluid machine, which can increase the pressure of gas and transfer gas side by side by input mechanical energy. The negative pressure fan is a kind of equipment which uses the air convection and the negative pressure air exchange to reduce the temperature. It is a kind of equipment which inhales the fresh air naturally from the opposite direction of the installation place and forces the indoor sultry gas out of the room quickly. It can improve any problem of poor ventilation, and the cooling effect of air exchange up to 90-97%.
That is to say, according to the principle that the kinetic energy is converted into potential energy, the centrifugal fan accelerates the gas by using the high speed rotating impeller, then slows down, changes the flow direction, and converts the kinetic energy into the potential energy. For example, in a single stage centrifugal fan, the gas enters the impeller from axial direction, changes into radial direction when flowing through the impeller, and then enters the diffuser.
In the diffuser, the flow direction of gas changes caused by slowing the speed converting kinetic energy into pressure energy. Increased pressure mainly occurs in the impeller, the diffuser followed in the process. While in multistage centrifugal fan, with refluxing device make the airflow into the next impeller, produce higher pressure.
The difference is that the negative pressure fan is designed by cad/cam, which has the characteristics of low investment cost, large air volume, low noise, low energy consumption, stable operation, long life, high efficiency and so on. At the same time, due to good dustproof, waterproof effect has become the first choice of cooling and ventilation in modern workshop.http://www.jnblower.com/