摘要 |
Around a bag (1) is an insulating thermic wall pref. comprising two suspended weighted sheets (7,8). The sheets from the water surface down to a depth of at least equal to that of the bag. Inside the bag is a recirculation system which also incorporates heating and water aerating facilities. Below the bag is a sealed, horizontal screen (12) which has the same surface as the net bag horizontal cross-section area os is pref. larger than it. |