GB1295942A - - Google Patents

Abstract

1295942 Microwave disinfection JAPAN MONOPOLY CORP and TOKYO SHIBAURA ELECTRIC CO Ltd 27 Jan 1970 [27 Jan 1969] 3957/70 Heading A5G [Also in Division H5] Moth, beetles, pupae, larvae and eggs in vegetable matter e.g. tobacco, tea, rush, are killed by heat treating the vegetable matter in an infra-red oven and a microwave oven supplied with a frequency greater or equal to 900 MH 3 . As shown, vegetable matter carried by a conveyor belt 12 passes in succession through an infra red oven 17, a microwave absorption trap 18, a microwave oven 19, and a microwave absorption trap 20. The conveyor 12 is made of low loss material e.g. glass wool fabric impregnated with fluorine resin and is supported throughout its length by a low low polypropylene plate 16. When the vegetable matter is shredded, flexible P.T.F.E. skirts 13 depending from polypropylene plates 14 abut the conveyor 12 to prevent the vegetable matter falling from the conveyor 12. The infra red oven 17 (Fig. 3) comprises a plurality of infra red lamps and reflectors 27a suspended from top of the oven. The absorption traps 18, 20 (Fig. 5A) comprises a water cooled absorption member 37. A detachable top cover 28 has a choke 29 to prevent sparking and leakage. A bottom cover plate 30 also has a choke 31. The microwave oven 19 (Fig. 6B) has chokes 32, 33 provided at the ends adjacent the absorption traps 18, 20. A magnetron supplies energy to the oven by way of a waveguide and flared connector 3. A mode stirrer 22 is mounted on upper cover plate 36 provided with microwave chokes 34. Chokes 35 are provided on bottom cover plate 24. It is preferred that the sections 17, 18, 19, 20 of the apparatus are fabricated individually but they could be fabricated integrally. The infra red heater prevents the surface temperature of the vegetable matter falling due to evaporation. The microwave energy may be pulsed.