Product Description

Forced Circulation Evaporators are tube evaporators and are ideally used when the boiling of feed liquid on the heating surfaces is to be avoided due to the salting and fouling characteristics of the liquid. Hence in these evaporators the flow velocity in the tubes is kept very high.

In these evaporators the liquid is circulated at high velocities in the tubes of the heat exchanger while steam is provided in the chest. This liquid is partially evaporated when the pressure is reduced in the vapor-liquid separator to the corresponding boiling temperature. High volume, low head axial flow circulation pumps are used for recirculating the crystal laden slurry in the evaporator and hence the operation of this evaporator is independent of the temperature difference. In the crystallizing operation crystals can be separated from the crystallizing slurry by adjusting the velocity of the circulating stream. These evaporators are ideal for handling liquors with high viscosity or which have a tendency to salt and scale during evaporations.

In general, forced circulation evaporators are required when the fouling characteristics of a liquid will cause problems if the liquid boils on a heating surface.These evaporators are also used for liquids with a high solids content and a high viscosity.

There are several other processes that require the use of forced circulation evaporators, which work particularly well as crystallizing evaporators.These include processes that produce salt, corn steep water and calcium carbonate.

Natural circulation evaporators are used in other processes such as those that produce anhydrous sodium hydroxide (caustic), sugar beet, liquors that are particularly foamy, or those that have a low to moderate viscosity, and precipitating liquids.

Natural/forced circulation evaporators are also necessary in effluent treatment plants, and in both the chemical andpharmaceuticalindustry

Features :

• Suitable for widest variety of evaporator applications.
• Ideal for crystallizing operation.
• High heat transfer coefficients. Positive circulation.
• Freedom from salting, scaling and fouling.
• Suitable for corrosive and viscous solutions.