Experimental Study Of Low Frequency Electromagnetic Fields To Suppress Fouling

Fouling phenomenon exists in all kinds of heat transfer process,the problem of fouling of heat transfer equipment brings many adverse effects to industrial enterprises.With the advantages of simple method,low cost and no pollution,electromagnetic scaling technology has been widely used and developed in recent years..Among them,the low frequency pulsed magnetic field has a good sterilization effect,and sweep frequency has a wide range of applicability to a variety of scales.The anti fouling mechanism based on Electromagnetic Analysis on low frequency and frequency sweep technology combine to carry out electromagnetic anti scaling device design and experimental research,to promote the development of related theory and technology,has good theoretical and practical significance.In this paper,the typical low frequency anti scaling technology(0.3-12KHz)as the research object,the hydrogen bond fracture mechanism was analyzed based on the theory of resonance for water molecules hydrogen bond breaking,using square wave harmonic,easy resonance characteristics,with a square wave based waveform signal;calculate the magnetic induction intensity and the number of turns according to Biot Savart cut law,design the winding type treatment chamber;based on the low frequency magnetic field sterilization best frequency range,processing cavity model and finite element method based on the boundary frequency and sweep frequency range(1.3KHz).Integrated signal generator,power amplifier circuit,transformer,processing chamber and so on,the design of low frequency scanning electromagnetic descaling device.The design of the fouling monitoring system,the operating performance of the system is analyzed,in order to carry out the experimental study on the effect of low frequency sweep electromagnetic descaling device on calcium carbonate fouling and microbial fouling as a platform to fouling resistance and inhibition rate as index were analyzed,the results show that:for the calcium carbonate fouling during the experimental period(200H)the electromagnetic processing of test pipe,the fouling resistance curve remained stable,fouling resistance was no obvious growth,this phenomenon is also confirmed by the actual image.The scale inhibition index shows that when the frequency is 0.3-2.5KHz,the scale inhibition ratio is 86.7%,and the scale inhibition effect is the best.When the frequency increases,the scale inhibition effect is reduced.For microbial fouling,fouling bacteria,iron bacteria,low frequency sweep field scale effect is obvious,the frequency of 0.3-2.5KHz,the inhibition rate reached 66.5%,with the increase of frequency,the inhibition rate decreased significantly,the rate of 8-12 KHz scale isonly 22.1%.To further verify the bactericidal effect of low frequency sweep of the electromagnetic field,the design of experiments,the static plate count and water quality parameters of the results show that the electromagnetic treatment without 38% less than the number of bacteria treated by electromagnetic,electromagnetic water treatment pH and cod were higher than those without electromagnetic water treatment.Through dynamic and static experiments,it is proved that the low frequency sweep frequency electromagnetic descaling device has good anti fouling effect.