| 摘要 |
Under-soil heating apparatus comprises a header flow pipe (2), a header return pipe (4), and a plurality of heating flow pipes (6) connected to the header flow pipe and a plurality of heating return pipes (8) connected to the header return pipe (4) running beneath a pitch. At each connection of a heating flow pipe (6) to the header flow pipe (2), and preferably also at each connection of a heating return pipe (8) to the header return pipe (4), there is a valve (16) for controlling the flow rate through each heating pipe (6, 8). The arrangement enables uniform heating of the whole playing surface of the pitch. The heating pipes (6, 8) are suitably buried in trenches (18, figure 3) at a depth, for example 350mm, deep enough to prevent damage to the pipes during normal ground maintenance. So that sufficient heat may permeate upwards to the surface (24), each buried pipe (6, 8) is covered with a layer of pea gravel (20) and a further layer of silica sand (22). <IMAGE> |
