OVC cooling crystalliser: after its facelift, a perfect match

In December 2020, the Minn-Dak Farmers Cooperative beet sugar factory in Wahpeton, North Dakota, USA, decided to upgrade its cooling crystallisation process for C product. They opted for the OVC cooling crystalliser from BMA, which perfectly matches the factory’s requirements following a facelift.  

The OVC-24 is the largest apparatus in this series, with a vertical product chamber that is 36.3 m high, has a diameter of 5.2 m and accommodates 24 cooling coils. These oscillate up and down, driven by hydraulic cylinders. The massecuite enters the unit at the top via a product distributor and runs down to the outlet at the bottom following the piston flow. The coolant flows through the cooling coils from bottom to top, in counterflow to the massecuite.

One of the OVC’s major assets is its ability to cool massecuite to very low temperatures, down to 40 °C. This results in higher yields than other solutions can deliver. The self-cleaning effect of the oscillating cooling coils also achieves consistently good heat transfer. 40 °C. This results in higher yields than other solutions can deliver. The self-cleaning effect of the oscillating cooling coils also achieves consistently good heat transfer. 

Thanks to the larger cooling surface offered by the compact arrangement of the cooling coils in the post-facelift OVC, the factory can achieve its massecuite throughput with just one unit. The cooling circuit comprises two separate loops, permitting better control of the cooling profile. Another improvement is the preconfigured hydraulic module that can be installed on top of the OVC, reducing the length of the hydraulic pipes. And the control system for the plant is now supplied as a completed module comprising both hardware and software.

In September 2021, all OVC shipments arrived in Wahpeton on time. The shell, split into segments, reached Galveston, Texas on board a car carrier – just before Hurricane Nicholas hit land. Despite the heavy rain, the logistics teams managed to load the HGV and set off for Wahpeton.  

The cooling coils arrived in Galveston a week later on another car carrier and were immediately forwarded to the construction site by road. Three containers were shipped from Europe to the port of New York. Because of a severe backlog, the shipment had to wait outside the port for a week to be unloaded. It was then forwarded by rail. 

The site supervisor from BMA was in charge of assembly. Completion and commissioning of the plant are scheduled for late 2021. 

Our project managers in Charlotte, North Carolina, and Braunschweig have together handled this project, while staff from Germany have been in charge of process technology and automation. Close collaboration among all global BMA teams is key to the success of this project.