Electric heating – Microwave heating – Field modification
Patent
1996-09-06
1999-11-02
Leung, Philip H.
Electric heating
Microwave heating
Field modification
219679, 219764, 219756, 219770, 34255, H05B 672, H05B 680
Patent
active
059775327
DESCRIPTION:
BRIEF SUMMARY
This invention relates to the heating of materials, which show dielectric properties and thus are susceptible for electromagnetic radiation within the frequency range from low radio frequency into ultra-high frequency where the latter frequency range commonly is called the microwave range.
Heating in microwave ovens is an established technique fast to thaw and cook frozen food-stuffs or to prepare dishes out of fresh, primary materials. A serious problem tied to the preparing in microwave ovens is, that the food-stuffs are unevenly heated owing to the small penetration depth of the radiation conditioned by the high frequency. A result commonly experienced is, that the food-stuff to be cooked is burnt on its surface while its inside not yet has reached the necessary preparation temperature.
Microwave ovens primarily are used for the heating of small batches, particular in order to save time. This requisite also exists as to the heating of large masses of organic materials, as at industrial food-stuff preparation, the drying of peat mulch and paper fibres, the sterilizing as well as the drying of offals and, the starting, the maintaining and the finishing of microbiological processes such as the rising of doughs, the fertilizing of vegtable waste residues and the rottening of wood fibres. There are needs to control chemical processes by heating, such as hardening reactions in plastics and composite materials. Further, needs are discerned, which are related to processes implying the treatment of wood chips and wood fibres with rottening fungi and other microorganisms in environmentally adapted pulp industries. All these different processes have in common, that it is particulary advantageous, that they are done by homogenous heating throughout the volumesin question.
The making of composts means the decomposition of vegetable residues by the use of microorganisms in aerobic processes. It is an established technique. The decomposition processes are carried out in for the purpose adapted vessels. Precise temperature control and suitable airing are necessary but difficult to maintain.
The processes work theoretically. As the masses of vegetables as well as of other biological residues often are characterized by an uneven water distribution, a frequent consequence is, that the decomposition processes within a batch differ in various parts as to timing and resulting end products. If the biological residues hold high contents of protein rich wastes, as a rule it is necessary to add or generate more energy for reaching and maintaining an optimal temperature.
Different techniques to convey heat have been tested. In the absence of anything better some of them are used. The use of radiators has shown, that hard, dry, and, heat isolating crusts easily are formed. Such crusts must continually be removed or avoided to arise and grow. The latter can be done by stirrino. Sawdust or other suitable ingredients are frequently added to generate necessary additional heat, implying reduced volume utilisation and raised process costs. Thuseconomic realities necessitate an elimination of at least a minimization of additions. The need of optimal heating is obvious to reduce additions.
It is envisioned, that one favourable, environmentally interesting route within paper and pulp industries will be the treatment of wood chips and wood fibres with rot fungi and other microorganisms. This will imply an emphasis upon a homogeneous temperature distribution within as well as a precise temperature control of large volumes.
Inevitable hygienic demands mean that composts and sludges have to be sterilized and dried at, even temperatures warranting hygienic safe and commercially manageable end products. A measure often taken to facilitate a drying process is to use vacuum. However, the evaporation of water consumes a lot of energy. A drying process has to pass homogenously throughout the whole volume of a batch. A cost efficient processing as well as quality improved end product is achieved, if heat is appropriatele transferred to or generated w
REFERENCES:
patent: 2602134 (1952-07-01), Nelson
patent: 3594531 (1971-07-01), Hough
patent: 3619536 (1971-11-01), Boehm
patent: 3691338 (1972-09-01), Chang
patent: 3843862 (1974-10-01), Staats et al.
patent: 3953702 (1976-04-01), Bickel
patent: 4978501 (1990-12-01), Diprose et al.
patent: 5276924 (1994-01-01), Hachima
patent: 5487873 (1996-01-01), Bridges et al.
patent: 5593713 (1997-01-01), Luz-Martinez et al.
Antrad System AB
Leung Philip H.
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