关键词: 超滤, 超声场, 脉冲电场, 物理场强化, 自动控制

Abstract:

Proposed in this paper is an automatic ultrafiltration system enhanced with ultrasonic and pulse electric field,which is used to overcome the concentration polarization and membrane fouling during the ultrafiltration and improve the automation level of ultrafiltration process.The system consists of a crude filtration loop,two ultrafiltration loops,a cleaning loop and a heat-exchange loop,and possesses excellent operation flexibility because it can simultaneously perform multi-stage or separately perform single-stage ultrafiltration.It also possesses a multi-layer distributed automatic control subsystem based on Kunlun MGCS configuration,which adopts an industrial personal computer and a Simens S7-200 PLC as the system hardware.The application of the proposed system to the concentration of pumpkin polysaccharides shows that,in the adopted experimental conditions,the average permeation flux increases by 1.15~2.53 times and the rejection by 15 points of percentage,which means that the system greatly improves the ultrafiltration efficiency and effect.

Key words: ultrafiltration, ultrasonic field, pulsed electric field, physical field-aided enhancement, automatic control