| 摘要 |
<p>A system for distributing controlled small quantities of water to various individual plants uses plugs of porous material exposed for appropriate lengths from the ends of spur distribution pipes. The plug may be of a porous foam (I), or of a fibrous material, or of parallel bristle or needle-like profiles for passing water by capillary action alongside and between the bristles. Adjustment of the length of plug exposed controls the outlet back pressure and hence the rate of discharge. The plug is fixed in position by a transverse pin through the plug and its supporting sleeve, or by an annular clamp, if sleeve and plug are sufficiently compressible, or by having a helical thread interface between the plug and its sleeve. Pref. (I) is polyurethane or polyester foam. Simpler in construction and/or adjustment than use of individual capillary jets or outlets with chicane baffles or throttle valves. The porous plug acts as an integral filter to prevent clogging. The outlets may be laid on the surface or at least partly buried.</p> |
