| 摘要 |
<p>A central vacuum cleaning system is disclosed, which includes a central tank (14) for collecting a liquid/debris mixture. A vacuum pump (23) is connected to an upper portion of the tank to maintain vacuum therein. Discharge means of the type of a sludge pump (28) removes the mixture from the tank to sewage. The sludge pump is so selected that it can overcome the vacuum prevailing in the tank and generated by the vacuum pump. Thus, the vacuum in the tank does not have to be cancelled, thus avoiding the need for the stoppage of operation, whenever the tank is to be drained. As a result, a more compact tank can be used for the purpose than in known devices. A continuous operation of the device regardless of the instant mode at the central tank is another advantage over prior art.</p> |
