How to dissolve sugar safely, economically and reliably

Making a solution of sugar is often a key part of the production process and to save money and time, food producers often carry out the dissolving step themselves, avoiding the purchase and transport of pre-dissolved sugar.

However, continuous dissolving is not straightforward and manufacturers face several challenges. The source and quality of the sugar vary, quite apart from the degree of refinement. The sugar ranges from pure white crystals to an almost black substance requiring further refinement at the plant. Even the size of the crystals varies widely.

On top of this, sugar dust can be explosive, so any dissolving system must prioritize safety.

Safe, economical and reliable

“We asked ourselves how we could offer customers the option of producing their own sugar solution continuously,” says Pernilla Tofft, Product Manager Mixing, Blending and Dosing, at Tetra Pak. “Conveying it through the pipes to where it is needed in the plant would save labour, and be much more convenient for higher capacity production sites.”

The resulting solution, developed by Tetra Pak company Miteco, is a patented coaxial injection method that is safe, economical and reliable. It works like this:

• Sugar is continuously collected and transported as slurry through pipes from as far as 50 metres away from the plant into the system.
• The turbulent flow in the pipes partially dissolves the sugar on its way to the suspension tank.
• Beyond the suspension tank, a final dissolving chamber allows only the dissolved sugar to continue into production, while any undissolved sugar is returned back to the tank.

Significant energy savings

“Our technology increases safety immediately, because the sugar can be stored outside the production area and is transported in water, therefore eliminating the risk of explosions,” Tofft explains.

There are also major energy savings. Since the sugar starts to dissolve before it reaches the suspension tank, a lower temperature can be used, which not only saves energy in the heating phase, but also in the subsequent cooling phase. This hydraulic conveying of the sugar also saves power, since it eliminates the need to transport the sugar pneumatically, using a blower from the silo.

Another advantage is that a sugar treatment process can be added to the system to handle sugar of varying quality.

Processing knowhow

“Our solution is based on many years’ experience of the CSD industry,” Tofft says. “We make sure we understand not only the challenges that dissolving sugar presents, but also our customers’ precise, individual needs. The breadth of our expertise means we can apply similar solutions to many other products and processes.”