离心风机是根据动能转换为势能的原理,利用高速旋转的叶轮将气体加速,然后减速、改变流向,使动能转换成势能(压力)。在单级离心风机中,气体从轴向进入叶轮,气体流经叶轮时改变成径向,然后进入扩压器。在扩压器中,气体改变了流动方向并且管道断面面积增大使气流减速,这种减速作用将动能转换成压力能。压力增高主要发生在叶轮中,其次发生在扩压过程。在多级离心风机中,用回流器使气流进入下一叶轮,产生更高压力。离心风机实质是一种变流量恒压装置。当转速一定时,离心风机的压力-流量理论曲线应是一条直线.由于内部损失,实际特性曲线是弯曲的。离心风机中所产生的压力受到进气温度或密度变化的较大影响州苗木 保定电动门 保定空压机 化粪池模具 微型蠕动泵 保定强夯 收费岛模具。对一个给定的进气量,较高进气温度(空气密度较低)时产生的压力较低.对于一条给定的压力与流量特性曲线,便有一条功率与流量特性曲线.当鼓风机以恒速运行时,对于一个给定的流量,所需的功率随进气温度的降低而升高。
A
centrifugal fan is based on the principle of converting kinetic energy
into potential energy. It uses a high-speed rotating impeller to
accelerate the gas, then decelerates and changes the flow direction,
converting kinetic energy into potential energy (pressure). In a single
stage centrifugal fan, gas enters the impeller from the axial direction,
changes to the radial direction as it passes through the impeller, and
then enters the diffuser. In a diffuser, the gas changes the direction
of flow and the cross-sectional area of the pipeline increases, causing
the airflow to slow down. 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 reflux device is used to cause the airflow to enter
the next impeller, generating higher pressure. A centrifugal fan is
essentially a variable flow and constant pressure device. When the speed
is constant, the theoretical pressure flow curve of a centrifugal fan
should be a straight line. Due to internal losses, the actual
characteristic curve is curved. The pressure generated in a centrifugal
fan is greatly affected by changes in inlet temperature or density. For a
given intake air volume, the pressure generated at a higher intake air
temperature (lower Density of air) is lower. For a given pressure and
flow characteristic curve, there is a power and flow characteristic
curve. When the blower operates at a constant speed, for a given flow,
the required power increases with the decrease of intake air
temperature.
