Volumetric flow controller for aerosol classifier
    8.
    发明授权
    Volumetric flow controller for aerosol classifier 失效
    气溶胶分选机的体积流量控制器

    公开(公告)号:US5006227A

    公开(公告)日:1991-04-09

    申请号:US371986

    申请日:1989-06-26

    摘要: A volumetric flow controller is used in connection with a virtual impactor classifier to control two separate flows in separate lines from an air pump. Each line has a flow control valve controlled in response to flow signals that are obtained from a pressure transducer that provides an electrical signal proportional to pressure. Pressure changes are sensed and the provided electrical signal is compared with a reference and will actuate a damper motor and move a flow control butterfly valve in the flow line for adjusting the flow when the pressure signal is different from the reference. The circuitry used provides for a dead band, so that changes in the butterfly valve setting will not occur unless the flow varies a selected amount, and also a timer control is used so that the motor operating the damper will be operated only at selected time intervals to prevent "hunting" or continuous operation of the valves. Further, temperature compensation signals can be provided as desired. The ability to control the flow volume provides for more accurate aerosol sampling and cut off points for the size of particles being sampled.

    摘要翻译: 体积流量控制器与虚拟冲击器分级器结合使用,以控制与气泵分离的两条独立流。 每条管线都具有响应于从提供与压力成正比的电信号的压力传感器获得的流量信号而控制的流量控制阀。 感测到压力变化,并且将所提供的电信号与参考值进行比较,并且将致动阻尼电机并且在流动管线中移动流量控制蝶阀,以在压力信号不同于参考值时调节流量。 所使用的电路提供死区,因此除非流量改变所选择的量,否则蝶阀设置的变化将不会发生,并且还使用定时器控制,以便仅在选定的时间间隔内操作阻尼器的电机 以防止“狩猎”或连续操作阀门。 此外,可以根据需要提供温度补偿信号。 控制流量的能力提供了更精确的气溶胶取样和切割点,以便取样颗粒的大小。