Samran Santalunai

The analysis and design of milk pasteurization system by using radio frequency electric fields

An analysis and design of dielectric heating system by using radio frequency electric field (RFEF) will be presented for the milk pasteurization process. It is a technique to transmit the electric fields into the intermediary by using the RFEF. To determine heat distribution in the dielectric loads, which electric field intensity are analyzed to be suitable for fluid and milk. In heating process, the heated material must be the polar molecules to perform the best efflciency of electric fleld transmission into the medium in order to increase the temperature of medium to greater heights. The electric fleld distributions on the lossy medium was analyzed using the CST EM STUDIO program. To investigate the difference of electric power on heating predicted by the theoretical model. In order to verify the simulation results. The proposed system is realized and experimentally examined. The applicator of RFEF with excited by 40 MHz signal and electric fleld strength of 1.6 kV/cm. In the results, it is found that the temperature of milk would be increased about 72.3°C, the process will be take approximately 2 minutes, and reduced population of bacteria 109,260 cfu/ml. Moreover, the investigation result revealed that the temperature of 71.7°C, it will be eliminated the bacteria in milk and extended shelf life of milk. The advantage of the principle of radio frequency electric flelds is that it can be applied to eliminate the bacteria in milk pasteurization.

Optimization of Capacitor Copper Plate for Dielectric Heating to Eliminate Insect

This paper presents the optimization of dielectric heating by using capacitor copper plate material. It has dimension of 50x50 mm. and the distance between plates is 3 mm. This work is used for preheating of insect and pests. Considering the RLC resonance circuit and the power per heating area, the rice weevils are used for sample dielectric. While the power transfer is varied from 10 - 80 watt and resonance frequency at 65 MHz for analysis, the rice weevils are died when the power transfer are more than 70 watt in 1 second. Moreover, It the power transfer is decrease, the period of time is increase. Approximate 10 watt of power transfer, the plate copper has less power so the rice weevils are breaking. Therefore, the power transfer has an effect on the heating area, which is the relation of the fast time.