Microwave food heating in tunnel oven - involves end chambers lined with absorption material, and microwave-reflecting or absorbing curtains

摘要

The items are transported through the tunnel oven (1) on a conveyor belt (5). The end openings of the tunnel have means to protect against microwave escape, with means of diffusing the microwaves as widely as possible. Material which absorbs microwaves is contained in hollow spaces (22, 26) at the ends openings, extending over part of the tunnel cross-sectional periphery, and fitted at intervals along its length. Near the hollow spaces are one or more freely suspended closure curtains (23, 25, 27) in the form of hanging strings or bead strings, of material which reflect or absorbs the microwaves, such as plastic or porcelain. There may be a hollow space between two closure curtains, and the latter may overlap the whole depth of the top and/or side hollow spaces, and may immediately adjoin them.