Drying
LIST KneaderReactors are the ideal choice for the drying of difficult residues or valuable products coming from various chemical processes. Typically, these difficult drying processes are characterized by demanding phase changes from pasty, sticky via viscous or crustforming or solid. The processes are limited not only by heat transfer but also by diffusion of the volatile materials through the pasty, sticky, viscous, or crusty phase.
The high torque LIST KneaderReactor design provides maximum self-cleaning, which eliminates dead spots and product build-up.
With the unique ability to handle all phases in the drying process, a single LIST kneader reactor can help our customers to significantly lower their investment and operating costs while delivering a consistent, high-quality end-product.
Properties
Example
Residue with Toluene diisocyanate (TDI)
The extremely robust continuous LIST TDI recovery process can easily handle fluctuating residue compositions and flow rates. The distillation residues may contain 30 – 70 wt% toluene di-isocyanate (TDI), a raw material for polyurethanes.
Evaporating TDI from the residue is difficult. The mixture tends to foam, and as the TDI content falls, the remaining material becomes first pasty and then highly viscous. Finally, at a free TDI content of 0.5 – 1 wt%, the residue solidifies into hard, free-flowing granular particles. The evaporated and condensed valuable crude TDI is fed back into the upstream process and improves the overall economy of the plant.
