服务与应用

Service and application

Contact Us

微波应用 Microwave applications

Factors influencing the effect of microwave disinfection

信息来源:http://www.weiboshebei.cn/发布时间:2013-11-26浏览次数:1547

Factors influencing the effect of microwave disinfection
    1 . The output of frequency magnetron
    Microwaves generated by the magnetron oscillator circuit . The gate electrode is replaced magnetron magnetic field to the flow control plate , the oscillation circuit mounted on a cathode , a special tube die , the movement of electrons can perpendicular electric field, thereby generating high frequency oscillations excited by microwave . Microwave for disinfection sterilization effect by the magnetron output power is influenced by the magnitude and frequency . Microwave frequency string smaller, longer wavelength , the deeper the penetration of goods , and therefore can be used to handle bulky items. However, the low frequency of the microwaves . Slow down the rate of heating . Thus prolonged disinfection . If the microwave frequency is high, molecular changes in direction or per unit of time will increase the number of rotation , collision , friction increases , and thus the object heating up fast, time is short, strong bactericidal effect , but its penetration is poor . Therefore only applicable to disinfect small pieces or small thickness items.
    2 . Magnetron output power level and duration of action
    Microwave disinfection effect not only affected by penetration , but also by the size and function of the magnetron power output duration of effect . Magnetron output power greater the effect , the stronger the electric field of the media. The more intense molecular motion . Microwave irradiation time items in a short article warming fast, so strong bactericidal effect . For example 2450MHz microwave irradiation 5mL bacteria , the role of 10s, when the output power is 540w , you can only kill E. coli, Bacillus subtilis spores can not kill , the power output is increased to 850 w, Bacillus subtilis spores can be kill , therefore , the effect of sterilization affected the article of energy generated by the microwave oven , and the amount of energy but also by the size of the magnetron output power , the oscillation frequency is low and duration of the irradiation of. Energy and power, frequency, time proportional relationship . That power, high frequency, long time , the energy is large, the effect is rape . But still need to consider the use of goods and frequency , power slaughter , time should be consistent . If large objects using high frequency , high power and long irradiation sterilization effect not only can not guarantee , but also a waste of energy. High frequency wave length making . To penetrate poor goods , items are likely to cause the outer temperature is too high , damage items.
    Yang Huaming , such as Bacillus subtilis variant spores Yin film. Be dressing kits ( 2008 , 50% moisture content ) and liquid water disinfection sterilization test test (400 mL water load ) , determined to do their killing wave Dl. Value. The results showed that the microwave to kill spores Dlo value decreases with increasing power .
    3 . Nature of the goods
    Various items of microwave absorption capacity are different, the impact on the number of microwave absorption disinfection effect , according to the nature of the article is generally divided into three categories : ① When the microwave propagating in the article to be absorbed significantly heat generating medium is called an absorption medium . Water , meat and high moisture content items are strongly absorbing dielectric absorption rarely turns o ② media , called benign medium microwave . Insulation class , for example: t quartz glass , ceramics, Teflon and other plastic products , the majority of microwave energy through a small part of the reflection, absorption reported less . Packaging used for disinfection of goods . ② good conductor of a class , does not absorb microwaves. Such as steel, brass, iron , silver and other metals can cause reflections . Above the second , three types of material goods , using microwave irradiation is not easy to achieve sterilization , but if the articles placed in water or steam environment by water molecules absorb microwave so the temperature rises, can achieve disinfection.
    Some researchers observed a plastic film bag of beef in the microwave sterilization process temperature changes . Found that the water content is low, the center temperature reaches 121 ℃, humidity nJ edge portions of 138 ℃, but the heat will increase the moisture content items . The only change 12-3 ℃ temperature difference . wela , etc. The variety of bacteria, actinomycetes and other exposed on phage microwave radiation frequency 2450MH2
Next , there was found only in the presence of water , microbial activity was lost . In dry conditions, even if the exposure time , if the microorganism is also not affected by microwaves . Hard was 240Lw. Frequency microwave irradiation natural 2450Wz soil samples and found that both the natural soil bacteria or actinomycetes , fungi , etc. have increased survival decreased with increasing soil moisture . When the humidity reaches 52% of the soil , a variety of Yan that all died. wela etc. also observed under microwave radiation to increase the temperature of the wet soil with microwave irradiation power increased. Dry soil in the power of any microwave irradiation , still maintain the original temperature.
    4 . Location of items in the microwave
    Furthermore, all of the microwave oven has a cold point , in this position the article unacceptable microwave radiation injury rest position . DDuglM (1990) in a sterile catheter experiment, with Yin article uniformly enemy in the microwave oven , and the location number with the A-F, disinfection found article A point not reached sterilized catheter F point position sometimes disinfection, sometimes not achieve disinfection , and when these two positions away from the catheter invariably achieve complete sterilization . Therefore, when using the microwave oven to avoid the attention of the cold zone in the microwave oven , or to release the article rotating electric heater or the cold zone can be avoided .

previous:Microwave disinfection in the food industry next:Bactericidal effect of microwaves

AboutUs | Sales and application | down load | talent resources

Address: No. 3 Dongcheng Road, Xin'an Community, Chang'an Town, Dongguan City, Guangdong Province, China

Copyright: Dongguan Qixie Microwave Equipment Co., Ltd.

 24 hour hotline:Mr. Dai:13544892266

粤ICP备10204892号