Innovation at FoundOcean: Our Mini-Batch Mixer

Our Sales Director, Andy Venn, talks about a recent design success story: the Mini-Batch Mixer. 

FoundOcean is proud to have a flexible and adaptable team who can meet each client’s individual requirements. Last year, Van Oord approached us with an interesting scope of work on the Sofia offshore wind farm. 

At 1.4 GW, Sofia Offshore Wind Farm is on track to become one of the largest single offshore wind farms in the world. It will comprise 100 14 MW turbines sited on Dogger Bank in the central North Sea, approximately 195km from the UK’s northeast coast. Now under construction, the project is 100% owned by RWE. 

The work involved grouting the concrete access platforms on the extended monopile foundations. The quantities of grout required were going to be much smaller than on a typical job, and had to be poured with care and accuracy. So, we deployed a mixer that could manage this operation. Usually we build our mixers ourselves, in our Livingston workshop, but we were close to capacity at the time, so we asked our Venterra Group partner, Osbit, to produce the Mini-Batch Mixer (MBM) that we needed, based on our concept design. 

Size 

The MBM is much smaller than our typical mixers. It is 2.5m high, 2.5m wide and 5.5m in length – the size of a standard shipping container – making it efficient to transport. This smaller size also makes it much easier and safer for our offshore teams to clean too.  

Despite its small size, when we first started to work on the design, calling it the “high strength small batch bulk fed mixer” was a bit of a mouthful. Almost immediately – for reasons unknown – the MBM was nicknamed the Honey Badger. Just an affectionate ‘pet name’ for this adaptable little mixer! 

Automation 

The MBM is our first unit to utilise fully automatic technology as well as Programmable Logic Controllers (PLCs) and digitisation. We had been eager to introduce these technologies to our mixer fleet and so were excited to incorporate the automatic system into this design.  

On the control panel, the two key measurements to be set are the quantities of grout powder and the required density of the cement output. Our new mixer will then weigh how much grout is in the pan and uses this information to calculate how much water is required to achieve the correct density. Therefore, instead of the team having to mix the grout until that density has been reached, we can continuously guarantee the density. The ability to set required amounts and density means that there is less scope for human error and also less wastage.  

The PLC is also helpful for monitoring, as it tells the operator what stage of mixing the machine is at, estimates timings and measures how much water or cement has been used so far. Working offshore and around machinery can be a very noisy environment. Now, instead of one engineer trying to shout down to the other at the bottom, a green bulb lights up on the PLC. Marvellous!  

Overall, manual workload is reduced, meaning the staff spend less time being physically adding the grout. Instead, the team can focus on the necessary QA processes and the monitoring and cleaning of the mixer to support high-quality productivity.  

This may have been the first FoundOcean mixer to utilise automation, PLCs and digitisation but we are now taking those elements of the design into our new builds for other mixers.  

How does the Small Batch Mixer work?  

The MBM (aka the Honey Badger) is fed by a silo containing the material. After the operator sets the requirements on the control panel, the silo feeds the powder into a surge tank and weighs the specified amount of dry cement. This is then fed into one of two mixing pans and mixed with water until the desired density is reached. Once mixed, the grout drops into the holding pan below and from there is fed into the pump.  

Features  

• Option of Bulk or 25kg bag fed: the grout powder can be fed through the silo but there is the option of manual feeding too.  

• Weigh scales: two sets of scales, one on the surge tank and one on the mixer tank. 

• Small footprint: only 20ft. 

• PLC (Programmable Logic Controller): select the required volumes and monitor progress.   

• Built-in dust box: keeps unit clean; also good for ventilation. 

• Easier to clean: simply flush through with hose.  

What’s Next?  

The MBM has been a great success. Our team like working with it and we’ve had very positive feedback from our client.  

The mixer was the first of its kind and is our first to have scales built into it, something that has been revolutionary for the team running it. Whilst this is currently our only one, having the design in place means we can easily create more of this model if required.  

Already, much of the successful technology from this mixer has been implemented in new larger scale designs during 2024. We built two other mixers with PLCs last year. The interface makes it much easier for the teams running them to communicate, especially on our larger scale mixers where the team may be working across several different levels.  

This is a success story that will influence many new designs at FoundOcean. We were thrilled to be able to provide the project with a fit-for purpose design whilst also innovating our design and upgrading our future mixer equipment.  

Does your offshore project have specific challenges that need addressing? If so, contact us today to find out how FoundOcean could help create a solution for you.