Ultrasonic-Pulsed Electric Field Preventing The Scale In Heat Exchange Equipment

The scale widely in the heat transfer process reduces heat, increases the consumption of energy and production costs, affect the normal production and makes the environment polluted, so it is always a hotspot to prevent scale.This experiment designs an equipment combining the ultrasonic field with pulsed electric field to process the generating solution of CaCO3, CaSO4 and Ca3(PO4) 2 from the main scale of sugar refinery, and studies its effect to prevent and remove the scale. The best anti-scaling parameters are determined by orthogonal experiment. The crystal form and size and structure were discussed by using the optical microscope and electronic microscope and X-ray diffraction techniques. The simulation solution of sugar clear juice treated by the equipment is researched to confirm the effect to prevent the scale in the sulfite sugar refinery. The experimental results are as follows:The parameters of ultrasonic field:frequency 20kHz, Power O-200W; The parameters of pulsed electric field:frequency 0-0.02Hz, voltage 0-5kV; The insulating material for the equipment is the PTFE.The optimal parameters of the synergy combining the ultrasonic field with pulsed electric field to CaCO3, CaSO4and Ca3(PO4)2:ultrasonic power 100W, pulsed voltage 3kV; processing time is 2min.The generating solution for CaSO4 crystals is processed by the equipment. The nucleation induction period is shortened by 60.00%, the rate of forming the crystal nucleus is accelerated by 81.62%. The growth rate of crystal nucleus is obviously slowed down by 54.76% because the driving power is diminished. Therefore, lots of crystal floats in the solution instead of depositing onto the surface.The coordination treatment combining the ultrasonic field with pulsed electric field significantly makes the CaSO4 crystal particle small and in disorder, but don't change the crystal structure.The coordination treatment combining the ultrasonic field with pulsed electric field has good effect, and the rate of preventing scale is 66.38% in the simulation experiment. It proves that the coordination treatment can effectively control the scale generation in sulfite sugar refinery.