| 摘要 |
A negative pressure difference water supplying system comprising a water tank (11) having a water surface at a first level (13). A water pipe (16) having an inlet end (21) connected to the tank (11) and an outlet end (23) open at a second level (24) lower than the first level (13) extends through a third level (25) higher than the first level (13). A plurality of ceramic porous tubes (17 to 20) are connected in the water supplying pipe (16) within the area (26) to be irrigated for allowing water to penetrate through the porous tube wall into or out of the porous tube (17 to 20) depending upon the pressure difference between the inside and the outside of the porous tubes (17 to 20). A return pipe (27) with a circulating pump (28) at the downstream side of the porous tubes (17 to 20) may be provided for circulating the water through the system. Alternatively, the system may comprise only a single water tank (31), a circulating pipe (32) having the porous tubes (33) inserted therein and a circulating pump (37) for sucking water from the tank (31). <IMAGE> |
