Overflow systems are designed to optimize the efficiency of the dredging process by draining excess water and leaving more weight available for the payload, thus limiting the amount of turbulence in the hopper.
During the overflow process, the aim is to remove excess water from the hopper, making room for more payload. However, with a regular overflow, the excess water can flow freely. This results in a chaotic process with large quantities of air mixed in the flow.
When released from the vessel, some of this mixture enters the inlets, such as the auxiliary pumps. This can result in loss of performance and even component failure. Due to the increased presence of air, the mixture ‘floats’ to the surface. This creates the characteristic plume, which has an adverse effect on the local ecosystem.
Tackling the issues caused by the overflow process, Royal IHC decided to develop a brand new solution for the industry, the patented Plumigator® system.
So, in order to present this new development to our readers, we decided to talk to Erwin Bijvoet – Product Manager at IHC, the man behind the team that gave birth to this new technology.
DT: The journey for new technologies is always an exciting one. This was certainly the case with IHC’s Plumigator, would you be so kind to share some insights on the origins of the IHC’ Plumigator overflow technology?
Erwin Bijvoet: Walter Beij – IHC’s captain/dredgemaster – came with the idea of a successor for the anti-turbidity valve. He experienced a positive effect on the plume and auxiliary equipment with a proper working environmental valve.
However the anti-turbidity valve is only used on projects with strict requirements with respect to turbidity. An anti-turbidity valve is not self-regulating, requires a lot of maintenance and is not easily accessible. After laboratory testing we did a full scale test on the Easydredge®.
With valuable results from the Easydredge® test we went back to the laboratory and redesigned the Plumigator. This improved design was installed and is still operational.
DT: What are the advantages of this technology?
Erwin Bijvoet: We engineered a solution containing no moving parts, that was self-regulating and also compliant with DR68, guidelines for the assignment of reduced freebord for dredger. The Plumigator can also be retrofitted to any existing telescopic overflow.
DT: Can you tell us something about the major benefits of using this technology?
Erwin Bijvoet: The Plumigator® overflow not only offers increased flexibility, but delivers a range of other benefits:
- Reduces the dredge plume;
- Improves performance of auxiliary equipment by reducing the air underneath the vessel;
- Prevents wear of auxiliary equipment.
DT: How does the IHC’s Plumigator overflow work in simple terms?
Erwin Bijvoet: With smart flow distribution the amount of air entering the overflow is reduced. As a result less air leaves the overflow.
DT: Have you already received some feedback from the users?
Erwin Bijvoet: The Plumigator is installed on one vessel, the TSHD SOSPAN – DAU. We received positive feedback from this launching customer. You can hear this in Jaap Verduijn’s story – captain of TSHD SOSPAN – DAU in the following movie.
Two more are to be installed, on dredger B.E. LINDHOLM for Weeks Marine and one on the new build Lesse for de Boer Dutch dredging.
At the end we asked Erwin Bijvoet what are the latest innovation for the dredging industry that IHC is currently working on?
Erwin Bijvoet: IHC is active in developing sustainable solutions. Like the Plumigator overflow, LNG-powered trailing suction hopper dredgers and cutter suction dredger and fuel saving technology.
Furthermore, IHC is developing dredge equipment that enable customers to perform projects more efficiently, such as new dragheads for hard soil conditions.