The single walled dredge pump

The single walled dredge pump

May 15th 2018 I BY BAS FROM IHC I READING TIME 3 MINUTES
Dredge pumps lie at the heart of the dredging challenge. The cost-effectiveness of dredging today depends, to a large extent, on their performance. The pump’s power, capacity, resistance to wear as well as its general robust and reliable character, are essential features. ShipSupport offers a complete range of IHC dredge pumps, available in different series. Each series are available as single-or double-walled, inboard or submerged with suction diameters from 250 to 1,400mm (customized pumps excluded). In this article we’re going to take a closer look at the single walled centrifugal pump and its components.

Dredge pump

The hydraulic design of the dredge pump, whether it's a single- or double walled execution, is formed by extensive CFD analysis and lab tests; the construction of the dredge pump is based on hands-on experience with dredge pumps in the field. Its main characteristics show in the type code. For example HRMD 141-30-70 means it’s a High efficiency Medium pressure Pump with an impeller diameter of 141 cm and 30 cm width. The diameter of the suction inlet is 70 cm.


The shaft assembly is either a bearing block or a gearbox. This depends on the available space for installing the pump. An expansion piece connects the pump to the dredge pipeline or suction tube, compensating for the varying distance during operation.


Single Walled Dredge Pump

Flushing system

The dredge pump usually has a water-flushing system on either the shaft-side, the suction-side or on both sides. This prevents dredge spoil that flows inside the dredge pump from getting between the impeller and the wearing plates and causing sedimentary deposit around the shaft seal. Flushing of these areas also reduces wear in these areas. Independent water pumps supply the flushing water to the dredge pump. A degassing installation connected to the degassing expansion piece can be applied to remove gas from the gas containing silt to avoid pressure and flow drop and to prevent an explosion due to flammable gasses.


Primary parts

Besides above mentioned components the dredge pump always includes the following primary parts:


Impeller

1. Impeller

Is installed in the pump casing. The dredge soil is driven through the pump assembly by the rotating action of the impeller. Rotation-direction depends on the position of the dredge pump’s discharge outlet.

Pump casing

2. Pump casing

Is installed between the shaft cover and the suction cover. It contains the impeller and provides a channel for the dredge spoil to flow through.

Shaft cover

3. Shaft cover

Connects the pump casing to the pedestal and seals the pump casing’s shaft-side.

Shaft Seal

4. Shaft seal

Is installed on the water chamber’s inner face and prevents water and dredge spoil from leaking from the dredge pump to the surroundings.

Suction Cover

5. Suction cover

Is attached to the pump casing, sealing its suction-side, closing the front side of the pump.

Suction nozzle liner

6. Suction nozzle liner

Is installed into the suction cover’s inlet hole and prevents wear of the suction cover inlet by dredge spoil.

Water chamber

7. Water chamber

Is installed on the shaft cover and contains the throttle plate and the inlets for the shaft-side flushing water

Wearing plates

8. Wearing plates

The shaft-side wearing plate is installed between the impeller and the shaft cover, the suction-side wearing plate between the impeller and the suction cover. Both are meant to prevent wear to the covers.

Please note that the maximum allowed pressures, speeds, accelerations etc. always depend on the type and construction of the dredging equipment. For more information or assistance please contact us.

Bas rijkse
Written by

Bas Rijkse

Royal IHC logo Product manager dredge line components