Cooling fan introduction of the fan

In some small and medium-sized cold storages, through the combined use of air coolers and refrigeration units, chilled or frozen goods in the warehouse are refrigerated, or items are frozen. The air cooler, professionally known as an air cooler for refrigeration. In the structure of the air cooler, there is an important component called "fan". Through the flapping of fan blades, the air in the cold storage exchanges heat with the evaporator, thereby realizing the cooling of the ambient temperature. That is, the fan plays a role in forced circulation of the air.

The fan is a device for conveying air or gas composed of an impeller (blades), a motor and a casing. There are many types of fans. Common fans in air conditioning, ventilation systems, and industrial production include axial flow fans, centrifugal fans, and cross-flow fans. Among them, the axial flow fan is composed of an impeller, fixed blades and a casing. The air flow flows along the axial direction and is a fan driven by a belt or directly connected. The centrifugal fan is composed of a rotor or impeller, a diffuser and a volute.

The air flow passes radially through the impeller and is a fan driven by a belt or directly connected. The cross-flow fan refers to a fan in which air enters from one side of the edge of the impeller in the direction perpendicular to the vertical axis, passes through the inside of the impeller and leaves the impeller from the other side.

For general-purpose axial flow fans, structurally, there are motor-direct-connected type, coupling-driven type and belt-driven type.

The blades of the impeller are generally evenly distributed.

There are various materials for the blades, generally including steel plate material, aluminum alloy material and carbon steel casting. The blades are fixed type and adjustable type. After the impeller is assembled, balance correction is carried out. The impeller and the main shaft are generally connected by keys. There are fastening devices in the longitudinal direction of the shaft and shall not be loosened during operation.

The air coolers used in small and medium-sized cold storages generally use low-noise and energy-saving fans. The fans are marked with signs indicating the rotation direction of the impeller. The noise of the fans is measured before leaving the factory and complies with the provisions of relevant national standards. Before the air cooler operates, the condition of the fan should be checked first: observe that the fan blades are intact and undamaged, the blades rotate flexibly, operate smoothly and lightly, without abnormal noise, jamming and other phenomena, and there is no oil leakage at the bearing part. When in use, the grounding wire of the motor and the grounding of the external device should be effectively connected.

When selecting a fan, in addition to considering the external dimensions, current, power, air volume, static pressure and rotation speed, it is also necessary to consider its use environment, noise, etc. Air volume refers to the volume flow rate of gas conveyed by the fan in unit time, also known as flow rate. Generally, it refers to the amount of gas conveyed in working condition. When selecting a type, the air volume required by the system is considered first.

Wind pressure refers to the total pressure, which is the sum of dynamic pressure and static pressure. The magnitude of wind pressure is determined by the resistance of the pipeline system and dust removal equipment. Rotation speed refers to the number of rotations of the fan per minute.

In order to make the fan operate reliably, when selecting a fan, it should be considered that the ventilation duct system is not tight and leaks air, as well as errors in resistance calculation. Generally, there should be a margin for the air volume and wind pressure of the system.