Listen To The Pump Master, His Story Never Wears Down

Example of a worn impeller at the Damen Dredging Experience
Example of a worn impeller at the Damen Dredging Experience

This week is the triannual WODCON conference1. This edition will be held in lovely Copenhagen, in itself already a reason to be there. But there is more, the program is packed with interesting items. Starting with the opening ceremony with the Danish minister of transport and the Corporate Executives Discussion on sustainability. The Fehmarnbelt Tunnel Link will be a hot topic all through the program. My personal suggestion would be to attend Session 4: ‘Hydraulic Transport’ on Tuesday 17. Two of my highly regarded colleagues will be presenting their work on very interesting topics.

Damen colleagues present at the WODCON 2022, (l) Rick Bekkers, (r) Suman Sapkota
Damen colleagues present at the WODCON 2022, (l) Rick Bekkers, (r) Suman Sapkota

Rick Bekkers has been involved in the development of our new ProDredge edition. It is a slurry transport estimation tool. Where Ewout van Duursen has been working tirelessly on programming the tool, Rick has been checking the models and the results against known literature. He will show you the new reports generated and the insights they will give you for evaluating a proposed dredging system.

ProDredge presentation of a dredging system to be evaluated
ProDredge presentation of a dredging system to be evaluated

Suman Sapkota will be presenting his favourite topic: ‘Erosion estimation on the impeller blades of centrifugal dredge pumps’. He has been working on this topic ever since his own graduation project.2 Over the years he spend pondering over this issue and gradually grew in experience with the problem. Based on his ideas, he managed to start a cooperation with the Delft University of Technology and have a master student working on the practical details of his plans. Previously, I’ve written about the graduation of Wim Kleermaker in another article.3

Wim Kleermaker during the practical phase of his graduation in dredging
Wim Kleermaker during the practical phase of his graduation in dredging

Suman has been concentrating on gathering the various models for wear under different conditions during his own graduation. The results from his simulations could only be checked against my own experience with badly worn impellers and disasters. Immediately introducing observer bias and survivor bias. So, for this project Suman really wanted to include experiments to have at least one observation to match the simulations.

Damen slurry test circuit with dredge pump and impeller
Damen slurry test circuit with dredge pump and impeller

And what a struggle it was, to get the experiments done. Wim really gained more experience in fixing troubles than in fact finding. In the end he managed. After operating for a couple of weeks under heavy load conditions for the dredge pump, the impeller showed a noticeable wear pattern. And they came up with an innovative way of measuring the erosion pattern and match the test results with the simulation results.

Comparing CFD results (l) with measured erosion (r)
Comparing CFD results (l) with measured erosion (r)

The paper Suman is going to present on the WODCON, condenses the results from Wim together with Suman’s previous work as a graduation student himself. Don’t get deterred by the in depth analysis. If you fancy, you can follow the comprehensive literature references and understand his model. Or, just enjoy the ride and inspect the interesting pictures with the conclusions at the end. If you are really interested in his work, just approach him in the break hours, he is very willing to share his experience with you.

If you can’t find him, or Rick. Drop by at our booth #27 in the lobby.4 There will always be someone to get you into contact.

Damen invitation for the WODCON 2022
Damen invitation for the WODCON 2022

References

  1. WODCON 2022, WODA
  2. Graduation Suman Sapkota: Where Wear Parts Were Worn Down, Discover Dredging
  3. Graduation Of Wim Kleermaker: Measuring And Predicting Wear In Impellers
  4. WODCON Dredging Conference, Saskia den Herder

See also

CEDA Dredging Days 2021: Sustainable Dredging And Innovation

Promotional banner of the CEDA Dredging Days 2021 (Credit: CEDA)
Promotional banner of the CEDA Dredging Days 2021 (Credit: CEDA)

Tomorrow, another event with a long tradition will start: the CEDA Dredging Days1. Due to the Covid issues, this time, it will be a virtual event, just as a lot of other regular happenings. Hopefully, it will be the last days of this dreadful period. I can’t wait to meet people again in real life. Back at the office, we are slowly starting to get back. But meetings with people far outside the regular circle were difficult. For instance, I was a member of the Technical Paper & Program Committee and the preparation was completely digital.

Home page of your CEDA Dredging Days on the Swapcard platform (Credit: CEDA)
Home page of your CEDA Dredging Days on the Swapcard platform (Credit: CEDA)

Now, the event itself is also digital. Of course, this is still not the real thing. Having a coffee and a chat in the lobby is a much more enjoyable experience than sitting in front of your screen. I have to say that with the Sawpcard platform2 selected by the organising committee, it is much easier to arrange your own program, adapted to your personal interests. Moreover, it will also facilitate meeting people with the same interest. In a sense, this might be an opportunity to approach those. In the real world, people will not get seated next to you when they have the same interest. And certainly don’t have them captioned on their chest.

Pump design workflow (inspired by Suman Sapkota)
Pump design workflow (inspired by Suman Sapkota)

As member of the TPPC, I had the opportunity of a sneak preview of the articles and presentations and I can guarantee there are a lot of interesting sessions. For starters, there are three presentations by my colleagues. Suman Sapkota will have presentation on his research in various novel methods to apply numerical research into the design of dredge pumps3. We are happy to share with you some experiences and insights on the Dredging Days.

Testing the non-radioactive density sensor
Testing the non-radioactive density sensor

Another presentation will be by Frank Bosman4. He has been active in the development of an instrument that will measure the mixture density, without using a radio-active source. This intelligent solution is not only more sustainable, but will also provide easier access to this information. If you don’t know the density, you are very likely to underperform with your dredge. He will present some experiences and data gathered on the performance of this system.

Example of recent electric DOP dredge family

Our last presentation will be by René Sens3. Less technical, but surely an interesting perspective on the future of dredging equipment. Everyone in the dredging community is aware of the necessity to change and adapt to a more sustainable approach of our dredging business. There is an urgency to reach the goals set by the UN to leave the world behind as a better place than we received it. Although usually an increase in size also increases the efficiency of a dredge, the UN goals look beyond that single parameter. With that in mind, small and medium size dredges will be far more interesting than at first sight.

Session 7: Young CEDA ask a CEO (Credit: CEDA)
Session 7: Young CEDA ask a CEO (Credit: CEDA)

There will be a lot more going on and I could produce a long list of other interesting presentations. I think you should also check out: Edwin de Hoog and Joep Goeree, Basel Yousef and Jeroen van Stappen, and if you really want to get academic: Janek Gundlach, Ebi Shahmirzadi and Arno Talmon. You can just add to your own list and see who also joins in in the audience. Other interesting sessions will be the student ‘Flash Talks’5 and the ‘Young CEDA ask a CEO’ session6 with Peter Berdovski and Kees van de Graaf. And I am very curious what the other working groups and commissions of CEDA have to present about their work.

Thursday evening is the big get together of the dredging community; meet you there! (Credit: CEDA)
Dredging Days as a they used to be: personal interaction (Credit: CEDA)

References

  1. CEDA Dredging Days 2021, CEDA
  2. CEDA Dredging Days 2021, Outsourced Events
  3. Session 5: Latest in dredging equipment and technology
  4. Session 2: Developments in modelling and measuring hydraulic transport, CEDA
  5. Session 8: Young CEDA Flash Talks
  6. Session 7: Young CEDA ask a CEO

See also

Student Interviews On Their Projects With Our Dredge Pump Slurry Test Circuit In Damen Nieuws

Damen dredge pump slurry test circuit on the outfitting quay in Nijkerk
Damen dredge pump slurry test circuit on the outfitting quay in Nijkerk

‘What sets men apart from boys is the size of their toys.’ And that wisdom applies to a lot of students that we’ve had at our company and have grown from boy to man working on our dredge pump slurry test circuit for their internship or graduation. As the test circuit has seen some intense activity these last months and yielded us with some very innovative concepts and possible new products, it was the right time to cover this interesting piece of equipment in the internal Damen Nieuws1 of January 2021 to share with all our colleagues. And that occasion in turn is an excellent opportunity to share with you the article and zoom into some of the details of the circuit.

General arrangement of the dredge pump slurry test circuit
General arrangement of the dredge pump slurry test circuit

Already more than ten years ago, we felt the need to have our own testing facility to experiment with the processes in our dredges or check the performance of new products2. After defining the specifications of the circuit, we had Hylke Visscher assisting us in designing the circuit for his internship. Subsequently he could actually supervise the manufacturing of the circuit for his graduation. Hylke worked in close cooperation with Arjan de Vries who in turn did his graduation on the building, outfitting and commissioning of the circuit. Both students from then are now esteemed and valuable colleagues as we have appreciated their performance on their projects.

After those ten years, we have a new generation of students working on the circuit. Arend van Roon recently graduated on his project with the circuit, as covered in my last post3. Currently Wim Kleermaker is preparing his experiments on the dredge pump. Upcoming is Williem Salim, not yet mentioned in the article, but now already starting his internship on the instrumentation of our laboratory. All project on the test circuit are supervised by Pieter van der Kooi as plant manager, Frank Bosman as student coordinator. Depending on the project, Ewout van Duursen, Suman Sapkota and me are supervising the student projects more on a subject level.

Various executions of a U-bend c-meter in the test circuit, for delivery and installed on a dredge
Various executions of a U-bend c-meter in the test circuit, for delivery and installed on a dredge

The odd thing you might notice in the loop of the test circuit is the U-bend directly after the dredge pump. Contrary to most first impressions, it is not to generate resistance, although it does so slightly. It is to measure how much sand has been transported. As the circuit is by nature closed, there is no way to check how much we’ve transported through the dredge pump. Sure, there is a density sensor4, but this will only indicate the so called volumetric density; how much material is there in the cross section. It will not differentiate between fast moving slurry and a slow sliding bed. In the extreme you could have a static bed, indicating a very high concentration. Multiplying this with a very high fluid speed, that is squeezed through the remaining aperture, you would expect an impressive production. Wrong! Not a single particle gets transported.

Enter: the U-bend. It measures the hydrostatic pressure differences over a certain hight in the upstream and downstream branches. This will cancel out the velocity differences but will yield the actual transported mass flow. So, that is how we can claim that we already dredged millions of cubic meters, all on the floor area of a 40 foot container flatbed.

Explanation of the U-bend measuring principle
Explanation of the U-bend measuring principle

References

  1. Testcircuit, Damen
  2. Innovation, Damen
  3. Graduation of Arend van Roon: Detecting Flow Regime And Optimising Transport Efficiency, Discover Dredging
  4. Production management, Damen

See also