| 摘要 |
To enable a practical RF oven to heat a wide range of product volumes for different operations such as baking or defrosting, an auxiliary removable box shaped metal electrode 8 is inserted underneath the product 3 to be processed. This electrode has a cross-sectional area comparable to that of the product to be heated and a height which minimizes any air gap above the product, subject to processing requirements. A polymer holder 13 (fig 6) may hold an appropriate number of auxiliary electrodes 8,8' so as to match the area of the product(s)3,3'. A polymer enclosure 5 separates the main electrodes 1,2 from the product chamber. Alternatively the auxiliary metal electrode may be replaced by a dielectric with a large dielectric constant of 100 or greater, for example the auxiliary electrode may comprise a polymer container 19 having modules filed with water 21. Fig 7 not shown discloses the use of ice added to the top of a product to reduce the gap under the electrode 1 and to promote uniform heating. |
