PURPOSE: To conduct manufacture by a simple operation by forming a polyvinyl alcohol film on the outer surface of a steel tank when a reinforced plastic lining double shell tank provided with a gap between the tank and the layer is manufactured, and then forming the layer.
CONSTITUTION: A reinforcing plastic layer 3 is provided while forming a gap 2 at the outside of a steel tank 1 as a tank body 4. A detecting tube 5 communicating with the gap is inserted from the upper part of the body 4 to the bottom, and a sensor 6 for detecting leakage water from the tank 1, sewage water flowing via the layer 3 is disposed at the bottom of the tube 5. In the case of manufacturing such a tank, the outer surface of the tank 1 is coated with polyvinyl alcohol solution, dried to form a polyvinyl alcohol film, and then the plastic layer 3 is formed. Thus, the gap is easily provided between the outer surface of the tank 1 and the layer 3.
WO/2000/046017 | REINFORCED CHANNEL-SHAPED STRUCTURAL MEMBER METHODS |
TAKAKUWA HIROSHI
SASADA SHINJI