Abstract:

Radio frequency (RF) electromagnetic wave has the advantages of high penetration depth and fast heating speed, which could save time in food sterilization process and preserve the nutrient contents and high quality of food to the largest extent. Taking tap water and sodium chloride solution as material, this paper studied the affecting regulation of factors on electric fluid ratio of anode to grid and the liquid heating rate by RF heating. Those factors included liquids height-diameter ratio, liquid air ratio and electrical conductivity. The results showed that when the liquid air ration was changing, the electric fluid ratio of anode to grid of RF heating machine first went up, then reduced and reached the maximum value. The lager was the electric fluid ratio of anode to grid, the faster was the RF heating speed. The larger the height-diameter ration was, the quicker of RF heating was. When the electrical conductivity of liquid was around 900~1 000 μs/cm, the electric fluid ratio of anode to grid was relatively larger and the RF heating of liquid was also relatively faster.

Key words: radio frequency, liquid , heating, electric fluid ratio of anode to grid, temperature increasing speed rate

摘要：

射频电磁波具有穿透性高、加热速率快等优点，可以缩短食品加热杀菌时间，更大程度地保留食品的营养及品质。以自来水和氯化钠溶液为研究对象，研究了 液体的高径比、液空比和电导率对射频加热设备的阳栅比和液体加热速度的影响规律。结果表明：液空比变化时，射频设备阳栅比先变大后变小，有极大值； 阳栅比越大，射频对液体加热速度越快；射频对相同质量不同高径比的液体加热时，液体的高径比越大，阳栅比越大，射频加热速度越快；当溶液的电导率在 900~1 000 μs/cm，有较大的阳栅比、较快的加热速度。

关键词: 射频, 液体加热, 阳栅比, 升温速率