| 摘要 |
<p>Pressure vessel contg. the prod. is included in a closed circuit through which a constant rate flow of steam is blown. Upstream of the vessel the steam is superheated as it passes through an indirect heat exchanger which serves as a condenser to utilise latent heat of satd. steam at a higher temp. than the superheated steam. The satd. steam utilised by the superheater is a fraction of steam branched from the main closed circuit between the vessel and the superheater. This fraction is equal to the quantity of water extracted from the prod. in the vessel and receives energy by passage through a compressor upstream of the superheater condensing circuit. A make-up heater is fitted to the closed circuit. The fraction of steam branched to the compressor is pref. of the order of a few per cent of the steam flow in the closed circuit. The dryer is for prods. such as beetroot pulp, brine, syrup, leaves and foliage, agricultural/food prods., papermaking pulp, seeds, granules, wood, terra cotta and plaster. Drying is effected with min. input of energy. The use of superheated steam avoids oxidn. and loss of quality.</p> |
