Application Background

Sulfuric acid is widely adopted as raw material in smelting, titanium dioxide and other industries, and dilute sulfuric acid with low concentration is generated after reaction. Evaporation concentration systems are applied to upgrade dilute acid to the target concentration for reuse.

Technical Description

Different evaporation processes are selected according to feed concentration and impurity contents in materials.

By number of effects: single-effect evaporator or multi-effect evaporator; multi-effect evaporators are further divided into forward-flow and countercurrent-flow types.

By film type: falling film evaporator, rising film evaporator and forced circulation evaporator. A supporting stripping process can further raise sulfuric acid concentration or remove fluorine and chlorine impurities from acid.

Graphite evaporation systems can concentrate dilute sulfuric acid to 60%–75% by mass fraction, while tantalum evaporators can achieve even higher acid concentration.

Forced circulation evaporation is suitable for feeds prone to scaling, crystallization, high viscosity, high concentration or containing solid particles. Forced circulation accelerates material flow velocity inside tubes and prevents wall fouling that deteriorates heat transfer performance.

Two graphite evaporator types are available matching different feed properties: block-hole graphite evaporator and shell-and-tube graphite evaporator.

Corresponding circulation pumps include graphite axial flow pump and PTFE axial flow pump selected based on medium characteristics.

Triple-Effect Forward-Flow Forced Circulation Evaporation Process

Triple-Effect Countercurrent Forced Circulation Evaporation Process

Triple-Effect Forward-Flow Falling Film Evaporation Circulation System

Triple-Effect Countercurrent Falling Film Evaporation Circulation System

Sulfuric Acid Concentration System for Jinchuan Group, Gansu Province

Hydrochloric Acid Contraction & Separation System for China Pingmei Group