| 摘要 |
The tanks 5, 80 contain a layer of light granules 100 which serve to support the plants 14 and float on the surface of the nutrient solution 84 or rest very lightly on the bottom of the tanks when their relative density is slightly greater than 1. This layer is displaced from the centre to the periphery of the tanks by a mechanical system, such as one or more revolving sectors 130 provided with vanes 132, or by a screw with a progressive pitch in a time equal to that of the growth of the plants 14. Plates 136, 137 and baffles 133 return the granules 100 coming from the periphery of the tanks to below the floating layer and over the entire surface of the tanks 5, 80. Systems for cutting roots and sucking up the waste are provided. The wire networks can be replaced by tubes or caissons floating or arranged above the nutrient solution. The revolving sectors or screws can likewise directly displace the plants 14 in the case of hydroponic cultivation. <<Arms>> provided with fins push the props at their tip. <IMAGE> |
