Specialty Pilot Plants
All Chemtech distillation systems are modular in design and so offer maximum flexibility when choosing the right evaporator, degasser, feed & discharge systems, heating, and cooling systems, vacuum pump systems, control systems, and matching heat transfer systems for your unique application. Standard systems are available for laboratory applications such as the Mini-4, Mini-5, and KDL-6 models. Scaled-up versions in stainless steel are also available.
As needs change, select from a variety of upgrade packages to increase the size of your evaporator, go from a medium to a high vacuum system, or add additional stages to your separation.
When a standard unit just won’t do, Chemtech offers a full range of engineering capabilities. Our engineers and technicians have the know-how and experience to assist with everything from the customization of smaller lab units to the completion of large-scale production plants.
Rolled Film Distillation Systems are a type of wiped film evaporation system (WFE). This special wiper system is used in most Rolled Film and Short Path Evaporators. This roller wiped film system has proven it has tremendous advantages in many applications over the years. The roller system consists of a cylindrical “basket”, composed of guide rods on which rollers are fixed. The rollers are made of a glass fiber reinforced PTFE compound. The roller wiped film system is driven by a motor from outside the distillation chamber. The centrifugal force presses these rollers into the liquid film flowing downwards. Since there is no mechanical load on the evaporation surface, scratches and “fouling” are avoided. The roller wiped film system guarantees a uniform, laminar mixing of the thin film on the entire evaporator surface. Due to overlapping of the rollers and wiping on the unheated areas, so-called “dead-zones” are avoided. At the same time, the liquid thin film on the rollers is continuously renewed. This results in a very low residence time of the evaporating feed on the evaporator surface. Build-up or caking of material on the evaporator surface and on the rollers, which might happen with other wiping systems, is completely avoided with the roller wiped film system.
The large clearance between rollers and guide rods facilities a “floating roller” which assures an even distribution of the feed material on the evaporator without causing damage to the evaporator. The necessity for a bottom bearing for the wiper basket is precluded by the floating action of the roller, so problems related to product penetrating into the lower bearing, or vacuum leaks through the bearing are eliminated.
External (RF) vs Internal (KD) Condenser: Short path distillation gets its name from the distance in which the vapor stream is condensed. In this case, the evaporator wall generates the vapors as the feed moves by gravity, while being agitated and distributed evenly, down the evaporator wall. The vapor stream travels a “short path” directly to the condenser which is located within the evaporator chamber. Since the vapor stream is immediately condensed, the short path distillation process precludes the vapor from forming vapor pressure. This allows ultimate pressures of 0.001 mbar to be attained which, in turn, allows heat-sensitive materials to undergo purification at much lower temperatures preventing degradation. It also allows for very high ambient equivalent temperatures to be achieved. Short path distillation in a plant setting is a continuous process.