Why are there three stainless steel balls on the roof of Hangzhou? What's the point?

It is a fan, a machine that relies on the input mechanical energy to improve the gas pressure and send gas side by side, and a driven fluid machine. Induced draft fan is a kind of equipment that generates negative pressure through the rotation of impeller and then draws air from the system (equipment). Generally installed at the tail of boiler, it is used to extract hot flue gas in the furnace.

In daily life, fans are usually divided into induced draft fan (negative pressure use) and blower (positive pressure use) according to the different ways of positive and negative pressure use.

Extended data:

Type of blower itself:

1, centrifugal blower

The newly designed two rows of large spacing suction cups which meet the "three-direction" standard are widely used in domestic foundry industry at present. Its main structural feature is two rows of tuyeres with large spacing, and the bottom coke burns to form two independent combustion zones. By lengthening the overheating zone, the overheating distance of molten iron and the intense combustion of bottom coke are increased, and the furnace condition is stable, the temperature of molten iron is high and the quality of molten iron is good.

2. Magnetic levitation blower

Magnetic suspension fan adopts core technologies such as magnetic suspension bearing, three-dimensional flow impeller, high-speed permanent magnet synchronous motor, high-efficiency frequency converter speed regulation and intelligent monitoring. When starting, it suspends first and then rotates, without friction and lubrication. The three-dimensional flow impeller is directly connected with the rotor, and the transmission loss is zero. It is a high-tech green energy-saving and environmental protection product.