BPSPS dryers' short residence time and agitated thin-film provide the perfect conditions for gently drying lecithin gums to low moisture levels while preserving color and meeting product specifications. The BPSPS lecithin dryer process has been used worldwide to maintain the lightest possible color and providing higher profits for lecithin producers.

BPSPS can provide evaporators in several design types, i-, historical - vertical designs, and horizontal designs incorporating residence time adjustment control.

BPSPS application experience includes soybean oil refining, sunflower oil refining, and canola oil refining.

In addition to the right technology, the BPSPS team has experience having installed 30+ evaporators for lecithin drying purposes worldwide. LCI can work with you to design and deliver component or modular systems incorporating the lecithin dryer for your application as well.

How It Works

The BPSPS lecithin dryer (also commonly referred to as a "thin film evaporator") consists of two major assemblies: a heated body and a rotor. Product enters above the heated zone and is evenly distributed over the unit's inner surface by the rotor. As the product spirals down the wall, bow waves developed by the rotor blades generate highly turbulent flow, resulting in optimum heat flux and mass transfer.

Volatile components are rapidly evaporated. Vapors flow either counter-currently through the unit. After exiting the dryer’s vapor nozzle, vapors are ready for condensing or subsequent processing.

Nonvolatile components are discharged at the outlet. Continuous washing by the bow waves minimizes fouling of the thermal wall where the product or residue is concentrated most.

The combination of extremely short residence time, narrow residence time distribution, high turbulence, and rapid surface renewal permits the BPSPS thin film evaporator to successfully concentrate wet lecithin gums to low moisture levels while meeting the most stringent dried lecithin gums product specifications.

Legend

1. Feed Inlet
2. Product Stream Through the Evaporator
3. Product Bow wave
4. Counter-Current Vapor Outlet
5. Co-Current Vapor Outlet
6. Concentrate Outlet

Design Principles

BPSPS offers lecithin dryers with the following design configurations.

Rotor Designs

• Fixed Clearance for all lecithin dryers. Rotor design upgrades include a modified feed designed made especially for lecithin drying applications

Rotor Orientation

• Vertical configuration is used for most applications. The vertical configuration provides reliable, efficient processing of lecithin gums. Units are available with either an internal or external bottom bearing.

• Horizontal designs are ideal for applications where longer residence times are required or where headroom is limited.

Vapor Flow

• Countercurrent flow is recommended for most lecithin drying applications to achieve low residual moisture content