How to choose the best Thin film evaporator?

Evaporation as a method for the purification of temperature-sensitive products has led to the development of thin-film or thin-layer evaporators. The temperature-sensitive product may be either the component with a high boiling point or the component with a low boiling point in the mixture. The goal was to decrease the amount of time that the product spent within the evaporator while still operating at low evaporation temperatures, which meant maintaining a low vacuum. It is important to keep the pressure, including the hydrostatic pressure that is caused by the liquid product itself, at a minimum in order to achieve the goal of achieving the lowest feasible temperature of evaporation at the hot surface.

A proper solution is none other than a liquid product’s thin film that is formed by a spinning wiper system on the inner side of a vertical evaporation pipe. This film is located on the inner side of the solution.

On the interior face of the wall, the revolving wiper ensures that the downflowing liquid supply is distributed in an even manner. The thickness of the film ranges from roughly 0.1 to 0.5 millimetres, and it is determined by the liquid’s viscosity, the type of wiper system, the rotating speed, and the amount of liquid that passes through. The superior radial mixing ability of this thin film ensures that there is nearly little hydrostatic pressure, minimum hold-up, and almost no temperature or concentration gradient. This results in the maximum evaporation rates, making it possible to produce temperature-sensitive goods of high quality. The majority of the vapours are sent upwards in an anti-current direction toward a condenser that is moving downward.

Ablaze Glass Works, an excellent manufacturer and supplier of wiped film evaporator is capable of supplying a thin film evaporator made of various materials such as Alloy, Borosilicate Glass, Stainless Steel, Glass-Lined Steel, etc.

The main applications of a wiped film evaporator are Glycerine evaporation, Methyl ester evaporation, pharmaceutical intermediates concentration, Lecithine drying, solvent stripping, etc.

Common Operations of Wiped or Thin Film Evaporators:

●     Concentration

●     Resource recovery

●     Devolatilization

●     Evaporation

●     Purification

●     Finishing

●     Distillation / Fractionation

●     Solvent Recovery

●     Drying / Dehydration

●     Reactions

●     Reboiling

●     Stripping

Technical Description:

A thin film evaporator is constructed out of materials that are highly resistant to corrosion, especially borosilicate glass 3.3 and glass-lined steel. Both of these materials provide an extremely smooth surface, which decreases the likelihood of the material adhering to the hot evaporation surface, where it would then remain and deteriorate. The use of clear borosilicate glass makes it possible to observe the interior of the evaporator’s surface while achieving the best possible adjustment of the spinning speed.

Operating Temperatures:

Both thermo-oil and steam are viable options for heating the evaporators. The wiper system’s construction that we came up with and the materials that it was made of determine the maximum temperature that can be tolerated on the inside of the evaporators.

The type of wall wipers used in the evaporator has a direct bearing on the evaporator's highest temperature:

●     PTFE Wall wipers    :           150°C

●     Metallic wall wipers :           200°C

Ablaze Glass Works is the most distinguished as well as noted thin film evaporator supplier in India, providing different wiper systems to cope with different most challenging varying requirements:

●     Corrosion and temperature resistant

●     The viscosity of the liquid product

●     Presence of solids

The heating jacket manufactured using glass-lined steel or borosilicate glass 3.3 can withstand a maximum temperature of 200°C.

Evaporation Rates:

The greatest rates of evaporation per area of heat transfer are based on the heat conductivity of the evaporator’s material as well as the significant temperature differential between the boiling point and the heating jacket temperature. It is possible for the organic solvents to evaporate up to 80 kg/h in borosilicate glass 3.3 with a 1m² heat transfer area.

How to choose the best Thin film evaporator?

When choosing thin film evaporators, there are a number of issues that need to be taken into consideration in-depth, including, in general:

- The capacity of production and operational parameters, which may include in-and-out concentration, processing capacity, annual operating hours, temperature, etc.;

-    Product characteristics include things like heat sensitivity, viscosity and fluidity, solid content, foamability, polymerization and crystallisation tendency, and many more;

-       Medium of Operation such as cooling water, water vapour, cleaning fluid, as well as many other similar substances;

-       The requirements for the selection of materials and the cleaning of surfaces during manufacture;

-       Conditions at the site include things like space, weather (if it's outdoors), how energy and items are connected, and working platforms, among other things.

-       regulations: includes those pertaining to safety, noise, and the protection of the environment, etc.