LIST Technology AG, Berstelstrasse 23, 4422 Arisdorf Switzerland

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.

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 5 – 10 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.

Your Benefits

  • Effective self-cleaning to minimize dead zones, product accumulation and product degradation
  • Excellent kneading and mixing for better homogenization
  • Low shear processing
  • Effective heat transfer
  • High surface renewal efficiency
  • Large free vapour volume
  • Precise and uniform temperature control due to large heat transfer areas
  • Continuous or batch processing
  • Processing of sticky and highly viscous products
  • Narrow residence time distributions (plug flow)
  • Wide and flexible range of average residence times
  • Reliable process scale-up from pilot to industrial units

Downloads

TitleDescriptionLanguageYearDownload
LIST technology for the Drying of Paint Sludges with Solvent Recovery

The increase in the amounts of paint and lacquer sludges from industrial processes combined with more stringent legislation, reduction in available land-fills, escalating costs, and the increasing pressure for residues to be processed at the point of origin has created a tremendous incentive for the development of new and economic concepts and techniques for their minimisation.

 English 2005
The Ins and Outs of indirect drying

Consistent with the diversity of chemical-process-industries materials that undergo drying, a wide variety of contact dryers have been brought to the marketplace. However, there is a common set of principles for their process design, and for specifying them.

 English 2003
Das Beste herausholen

Bei der Aufbereitung von Industrierückständen, Schlämmen und Sonderabfällen müssen nicht nur gesetzliche Vorschriften beachtet werden. Sinnvoll ist es, die Aufbereitung am Entstehungsort vorzunehmen; darüber hinaus sollte eine maximale Rückgewinnung an Wertstoffen sowie ein Minimum an unvermeidbaren Reststoffen gewährleistet sein.

 Deutsch 2001
Turning liquid into solids

Over time, different types of reacotrs have been developed in order to improve the stability of the polymerization process. This article Reviews those reactors designed for heterogeneous and homogeneous polymerization. It then explorres the production of solid polymer granules directly in a kneader reactor under evaporative cooling, which is seen as an efficient and reliable polymerization Technology.

 English 2001
LIST Technology for the recovery of toluene diisocyanate

In the mid seventies, LIST developed and industrialized a continuous process for the recovery of toluene diisocyanate (further TDI) from distillation residue. The process, which will be highlighted in this document, ensures the Maximum recovery of TDI. The final residue is transformed into a non-toxic (neutral) and easy to handle solid/granular material.

 English 2000
Integriertes Trochnen und Reagieren

Grossvolumige Knettrockner ermöglichen es, Prozessschritte zu kombinieren und damit Vorteile hinsichtlich Wirtschaftlichkeit und Produktqualität zu erzielen, speziell dann, wenn zähpastöse oder krustende Zustände zu bewältigen sind.

 Deutsch 1998
Polutex – Drying of industrial sludges and distillation residues

This paper elaborates on the constraints of the drying process of industrial sludges and distillation residues, such as, closed design and product containment, processing of sticky, crusting, or fouling intermediate phases, versatility, low energy demand, and single step drying. It then presents the mechanical, thermal and processing features as well as the operating principles of specialised single-shaft, DISCOTHERM B CONTI/BATCH, and twin-shaft, ORP (Opposite-Rotating Processor) CONTI, kneadersdryers.

 English 1998
Knettrocker vereinfachen Produktionsprozesse

Trocknen und Reagieren kombiniert – Die Verbesserung von Produktionsabläufen konzentriert sich heute weniger auf die Optimierung einzelner Verfahrensschritte, als vielmehr auf eine Vereinfachung des Verfahrensablaufs als Ganzes.

 Deutsch 1998
Specialized drying processing equipment

This lecture concisely reviews the development and evolution of specialised contact kneaders-dryers, presents the field of their application, defines the selection criteria, describes a basic design procedure, and closes with a list of parameters, that helps one to decide between the implementation of a batch or a continuous operating dryer.

 English 1998