23.10.2014

Optimisation of vacuum pans

Many sugar factories use vacuum pans that operate without process automation and without a powerful stirrer. BMA has the right solution that allows these vacuum pans to be optimised at relatively low cost.

Vacuum pans with a high potential

The suboptimal use of vacuum pans may have the following negative effects:

  • Higher heating steam pressure necessary to produce the stirring effect in the pan with the aid of the pressure difference
  • Poorer crystal size distribution
  • Low level of process reproducibility
  • Water has to be added at different points of the process
  • Lower centrifugation efficiency
  • Poorer crystallisation yield
  • Higher recirculation in the sugar house and higher steam consumption

By retrofitting a powerful stirrer, adapting the vapour chamber and automating the vacuum pan operation, the complete process can be optimised.

Optimisation details

As a first step, BMA takes a close look at the layout drawing for the installed vacuum pan, and the necessary pan adaptation measures are then proposed in the form of a quotation. This typically comprises the supply of components for converting the pan’s vapour chamber (or the provision of the corresponding drawings), and the supply of the stirrer and the drive.

Vacuum pan automation can be implemented by BMA Automation’s experienced process engineers in a number of ways:

  • For individual vacuum pans
  • For several vacuum pans with interlocked boiling processes
  • Integration of the automation systems in an existing process control system

The following systems can be used:

  • Simatic PCS7 AS 410 as the standard option
  • Simatic PCS7 Box System as a lower-cost option 
  • Other automation solutions, such as ABB or Rockwell, are also possible

Various interface options (ProfiBus, Industrial Ethernet, ProfiNet) are available for connection with the sugar factory’s own automation components.

For effective pan automation, the stirrer should be operated with a frequency converter. This allows better utilisation of the stirrer power for even improved homogenisation results and heat transfer. Controllers ensure that the stirrer drive is not overloaded.

Reliable measurement required

Dry substance content measurement plays a major part in optimising vacuum pan automation. It is essential for defining exactly the right seeding point and for reaching the optimal dry substance at the end of the pan boiling process. The DynFAS MW microwave measuring unit from BMA Automation combines very high measuring accuracy with reliability and is therefore an ideal solution.

The microwave measuring unit can also be used for other purposes, such as for measuring the dry substance content of the thick juice and of liquors, and for measuring the density of milk-of-lime.

Optimisation results

The optimisation measures for vacuum pans that are outlined above provide various benefits:

  • More constant boiling process
  • Addition of water and formation of fine crystals are avoided
  • Reduced recirculation volumes in the sugar house
  • Reduced energy consumption in the sugar factory
  • Effective utilisation of pan capacities
  • Overflowing and similar malfunctions are avoided
  • Simpler operation with a very high level of reproducibility

No matter whether the task at hand is to mechanically convert or to automate and commission vacuum pans: BMA has successfully completed numerous individual and large-scale projects and has acquired vast experience with the optimisation of vacuum pans.

CUSTOMER BENEFITS

  • Higher product quality
  • Reduced energy consumption
  • Optimised sugar house capacity
  • Automation, technology, microwave measurement and mechanical conversion from one single source

 

Safouane Chahid
BMA Automation

automation@bma-de.com

Steffen Kaufmann
BMA AG

engineering@bma-de.com