| 摘要 |
Ventilation ducting having a substantially oval and/or elliptical cross-section includes an intermediate section, and an end section at opposite ends of the intermediate section. Both the intermediate and the end sections include a pair of adjacent ducts. The ducts in the intermediate section are separated along their length by a common wall. The common wall may be perforated sheet, mesh or net material. The ducts at each end section are separate tubular members. An engaging device is provided at the intermediate section for suspending the ducting above the ground. A coupling device is provided at each end of the intermediate section for joining together adjacent lengths of the ventilation ducting.
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