Case study no. 20:
Sulphuric acid dilution
Initial situation
Large quantities of sulphuric acid H2SO4 are required as an electrolyte in the production of batteries. The acid is supplied to production in a highly concentrated form, but is bottled in diluted form. During the dilution process, a large amount of energy is released (dilution enthalpy), so that the diluted acid even exceeds its boiling point temperature at certain concentrations and begins to boil. This can mean the end for equipment components such as the tank.
Task
Design of a heat exchanger that is resistant to sulphuric acid up to a concentration of 90% and a temperature of 80°C. However, the temperature of the acid mixture must not exceed 60°C at any time.
Solution
The concentrated acid is dosed into the water reservoir depending on the mixing temperature. The already diluted acid is circulated from the mixing tank through a Calorplast PVDF tube plate heat exchanger and continuously cooled until the desired acid concentration is reached.
Result
The Calorplast tube plate heat exchanger made of PVDF is used in numerous plants around the world alongside the mixing tank.