Pumping station with efficiency increasing and backflow preventing structure

#The present invention relates to a pumping station comprising a structure which has at least one inlet chamber and at least one discharge chamber which is arranged at a different height, a partition arranged within the structure between these at least two chambers, at least one pump delivering a liquid through the partition into a discharge chamber of the structure, the discharge chamber having a discharge opening which is arranged at an angle to an outlet opening, wherein the upper edge of the discharge opening is situated below a liquid level which prevails in a discharge arranged downstream of the structure.

#Pumping stations, which are also referred to as water intake installations, dike or discharging intake installations, water lifting installations, irrigation pumping installations or under similar terms, have to deliver large amounts of water with small delivery heads. A general overview of systems of this type is disclosed by the essay entitled “Gestaltung von Schöpfwerken [Design of water intake installations]”, by Helmut Göhrke and Paul Winkelmann, published in KSB Technical Reports No. 11, August 1966, pages 28-36. With changing levels on the inlet side and with fluctuations in the external water levels arranged downstream of the pumping station, pumping stations have to cope with different delivery heads. Since the pumps which are in use, which are essentially of axial or semiaxial design, discharge only relatively small delivery heads, the slight fluctuations in the delivery head, which fluctuations are required for efficient operation of the system, are a problem for the design of pumping stations of this type.

#In order to keep the costs of a structure of this type low, vertical impeller pumps are predominantly used. For small delivery heads of up to approximately 2 meters the abovementioned essay has disclosed the use of what is referred to as an open impeller pump. In this case, a liquid which is to be delivered, after having passed the impeller, flows directly out of the pump housing, which is designed to be open on the delivery side, into the discharge chamber of the pumping station. As in the case of all pumping stations having the aforementioned intended use, a back flow preventing mechanism has to be arranged on the delivery side of the pump and is used, when the pump is switched off, to prevent backflows of liquid which has already been delivered. For this purpose, in known pumping stations, the discharge opening of the discharge chamber is fitted with a positively controlled non-return flap which serves simultaneously as back flow preventer and a shut-off element, cf. page 31, FIG. 3A.

#The invention will be described in further detail hereinafter with reference to illustrative preferred embodiments shown in the accompanying drawings in which:

#FIG. 1 is a schematic illustration of a pumping station having a simple design;

#FIGS. 2 and 3 depict pumping stations having an integrated measurement channel;

#FIG. 1 shows a pumping station 1 which has an inlet chamber 2 and a discharge chamber 3. Within the inlet chamber 2, which can be designed to be open or covered and in which a liquid which is to be delivered flows in from an external source, two levels of the liquid to be delivered are shown. LLWLin stands here for the lowest low water level and HHWLin stands here for the highest high water level which can occur on the inlet side of this pumping station 1.

#A partition 4 through which a pump 5 extends in a vertical arrangement is arranged on the upper side of the inlet chamber 2. One or more impellers are arranged in the lower part of the pump 5. A drive unit 6 arranged above the pump 5 brings about the drive of the pump 5. The transmission of power between the drive unit 6 and pump 5 takes place by means of a shaft 7. The drive unit 6 rests by customary fastening means on the cover 8 of the discharge chamber 3. In the example shown, the drive unit 6 is fastened on the cover 8 in an air-tight manner, so that the discharge chamber 3 itself exerts a siphon effect.

#The housing of the vertically arranged pump 5 is designed as a liquid-conducting device 9 which has an outlet opening 10 which is designed to be open and extends parallel to the liquid level. The outlet opening 10 lies at a height which is at least level with or lies above the highest high water level HHWLout on the side of the pumping station 1 having the discharge 11. The liquid-conducting device 9, which is designed here as an upward tube, opens with the open tube end or the outlet opening 10 into the closed discharge chamber 3, which is designed to be liquid-tight with respect to the inlet chamber 2. The discharge chamber 3 has a discharge opening 12 through which a connection is produced with the discharge 11 which is arranged downstream of the pumping station 1. Two levels are likewise shown in the discharge 11. The level LLWLout marks the lowest low water level here and the level HHWLout marks the highest attainable level on the discharge side.