Latest Developments in Dredge Pump Technology
Type:
Presented during:
WODCON XX: "The Art of Dredging" - 2013, Brussels, Belgium
Authors:
Bugdayci HH, Grinwis H, Munts E
Abstract: Dredging conditions encountered can vary extremely, in soil conditions, like clay and fine sands to gravel and hard rock, in depth from where the soil needs to be dredged and in sailing conditions to name a few. These varying conditions ask for diversified dredging vessels and accompanying dredge systems be it the drag head, the cutter head, the dredge pump or other dredge system equipment. Focusing on the dredge pump one can notice that some major steps forward have been made in increasing the productivity of dredging vessels in recent times by offering different types of dredge pumps catered to dredging conditions and the needs of the application. A recent example of these has been the development of a dredge pump with a large passage specifically designed to be used on heavy duty cutter dredgers; the Cutter Special. Since the introduction of the Cutter Special further developments have been realized in the field of dredge pumps.
A new type of dredge pump with an even greater ball passage has been designed specifically to be used in heavy duty rock operation; the Rock Special. Designing this pump posed even larger challenges than its predecessor. By combining the operational experiences and the latest developments in pump technology a new type of impeller has been developed; the Curve impeller. This new type of impeller can be used within existing high efficiency pumps without any modifications and will offer better suction characteristics and reduction in wear characteristics of the impeller. The wide range in which a jet pump is used in dredging operation still poses a challenge from a pump design point of view. A new type of pump has been developed with this in mind. It combines the robust design of a dredge pump with a reduction in the hydraulic forces of the pump which makes it an ideal pump to be used as a jet pump.
In this paper the mentioned developments will be explained in detail and these will be compared to existing solutions. The productivity of a dredger furnished with these latest designs will be compared to the same dredger furnished with existing equipment.
Keywords: dredge pump, ball passage , efficiency, NPSHr, wear characteristics, jetpump