Conveying Granulated and Powdered Sugar
July 19, 2018
Sugar is a key ingredient in many foodstuffs. Two primary forms of sugar are often used in food production processes: granulated and powdered sugar. In this blog, we look at the challenges associated with conveying granulated and powdered sugar, as well as the equipment solutions which UniTrak can provide for moving these materials.
All sugar is made by first extracting sugar juice from sugar beet or sugarcane plants. Using sugar juice, many different types of sugar can be produced by varying the production process in terms of the cleaning, crystallizing, and drying that is performed, as well as the amount of molasses that is added to produce brown sugar. Some types of sugar are used only in food production and are not available to the general public.
Granulated sugar (white sugar) consists of small crystals or pellets. It is perhaps the most common form of sugar used in food production processes. While dry granulated sugar tends to flow easily, without caking or packing, it is highly abrasive to conveying equipment.
Powdered sugar (also known as confectionery sugar) is produced by milling granulated sugar into a fine powder. It is available in different grades of coarseness. Finer grades of powdered sugar tend to absorb moisture which results in a tendency for the material to cake or pack. For this reason, small amounts of corn starch or tricalcium phosphate are often added during manufacture to reduce caking or packing.
Brown sugar is produced by adding molasses to white sugar. Since it contains more moisture than white sugar, the particles in brown sugar have a tendency to stick and clump together, increasing the handling challenges.
As a material, granulated sugar imposes significant conveying challenges. First, the material is abrasive, meaning that a conveyor has to be capable of withstanding the higher wear imposed on it by sugar granules or pellets. Secondly, sugar is hygroscopic, meaning that it readily absorbs moisture, leading to sticking and clumping. Thus, depending upon the equipment chosen, flow aids may be necessary to secure successful discharge from the conveyor and ensure a free-flowing supply of material. Finally, granulated sugar will ignite at high temperatures and the dust is highly combustible and explosive. Conveyors should therefore be capable of preventing fugitive dust emissions and static build-up, while eliminating any possible source of ignition once the material is in the conveyor.
Powdered sugar is marginally more dangerous than the granulated variety in terms of flammability and explosiveness, and the material tends to cake and pack. However, it tends to be less abrasive than granulated sugar owing to the milling process which reduces the crystals to a powder.
UniTrak has several equipment options available which address the challenges associated with conveying granulated and powdered sugar. These equipment solutions are described below.
When moving granulated or powdered sugar in volumes up to 115,000 pounds per hour in continuous operations, TipTrak™ bucket elevators are a preferred equipment choice. TipTrak™ conveyors feature fully interlocking bucket assemblies which all but eliminate product spillage. In addition, TipTrak™ Monocoque and PEC units with explosion-proof options feature fully sealed or fully enclosed designs respectively, which address the risks and problems associated with fugitive dust emissions and explosions. These conveyors come supplied with explosion-proof drive motors and anti-static drive assemblies which eliminate static buildup and sparking which could lead to an explosion. Optional high-wear bucket assemblies are also available to mitigate the abrasive effects of handling granulated sugar.
Powderflight aeromechanical conveyors are an excellent equipment choice for moving granulated or powdered sugar in volumes up to 65,000 pounds per hour. The fully enclosed operation of an aeromechanical conveyor minimizes product dusting, while the high velocity airstream leaves little residual material in the conveyor, providing it is run until empty. Moving material via a fluidized airstream, Powderflight units easily surmount the challenges of caking and packing that can occur when moving powdered sugar and will move granulated sugar without grinding or crushing the crystals.
UniFlex flexible screw conveyors are a good choice for intermittent or batch-type operations involving the handling of granulated or powdered sugar. These simple-to-operate and easy-to-clean conveyors can be supplied with a hopper to permit easy feeding from bags or sacks. Abrasion-resistant stainless steel or Nylon 6 tubes are available to handle the abrasion encountered when moving granulated sugar. UniFlex flexible screw conveyors are often the preferred choice for applications involving the transfer of smaller quantities of material over shorter distances.
Finally, many operations which handle or process granular or powdered sugar receive their input material in FIBC’s (Flexible Intermediate Bulk Containers, or “super-sacks”). Bagstander bulk bag unloaders from UniTrak offer a safe and effective way to discharge sugar supplied in FIBC’s.
To find out more about how UniTrak can help address the challenges of conveying granulated or powdered sugar, please contact our sales team directly.
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