Abstract: The relationship between moisture content and dielectric constant, dielectric loss, loss tangent and penetration depth of grass fruit microwave drying equipment and grass fruit was studied by TG-DTG thermogravimetric analysis and material dielectric parameter test system. The results show that the thermogravimetric process of grass fruit is divided into free water removal stage and bound water removal stage. The dielectric constant and dielectric loss have a trend of gradual decline and sharp decline with the decrease of water content.
When the free water of the grass is present, the dielectric constant and dielectric loss decrease gently. When the grass has only bound water, the dielectric constant and dielectric loss drop sharply. The larger the moisture content of the material, the larger the microwave energy loss and the smaller the penetration depth. On the contrary, the smaller the moisture content of the material, the smaller the microwave energy loss and the greater the penetration depth. The material penetration depth D and the water content ω exist y = Ae- ax + y , which is in exponential relationship.
没有评论:
发表评论