DESMI Marine Pumps: Modular S
The industrial design, compact with a clear-cut cylindrical form, together with the practical advantages such as easy assembling and modular construction of all components secure a long and unproblematic operation.
| Capacity Range: | 2-1800 m³/h |
| Pressure Range: | 5-220 mWC |
The success of the DESMI pumps is among other things due to the priming principle which will be thoroughly described below.
This principle means that the MODULAR S can pump a mixture of air and liquid and thus evacuate air from the suction pipe. By this, priming can be avoided and a foot valve is not necessary.
The pumps of the Modular S series can be supplied with free shaft end, in close-coupled design with electric motor or mounted on a base plate with petrol or diesel engine, hydraulic or electric motor.
Design Features
Priming
The priming is based on the diffuser principle, which means that the priming ability is independent of valves and other mechanical elements as it is the flow of liquid that carries the air.
In addition the diffuser principle has the effect that the Modular S can pump slightly polluted as well as air-mixed liquids.
Before first starting the pump, the pump casing must be filled with liquid. When the pump has been started, the liquid begins to circulate in the pump casing and the impeller canals. Thus, an air-mixed liquid is produced in the outer third of the impeller A and a vacuum is created in the suction piece of the impeller and the suction chamber B.
This vacuum makes the non-return flap C open, and air is drawn from the suction pipe into the suction chamber. The air-mixed liquid is lead through the canal D to the upper part of the pump casing E, where the flow velocity is low, and the air is separated from the liquid. The air escapes through the pressure pipe and the air-separated liquid returns to the periphery of the impeller through canal F. The direction of the flow is indicated by arrows. To allow free passage of the air through the pressure pipe ensure that valves, if any, are not closed during the priming.
The liquid circulation continues until the air has been removed from the suction pipe and the pump will then function as a normal centrifugal pump.
If, for some reason, air penetrates into the suction pipe, and the pump stops pumping, the priming process starts again, as described above, and continues until normal pumping has been resumed.
