Case study no. 8:
Production of solar cells
Initial situation
One production step in the manufacture of solar cells is the etching of silicon wafers in wet benches with highly concentrated mixed acid consisting of nitric and hydrofluoric acid.
The reaction between mixed acid and silicon is highly exothermic, so that the acid heats up.
As the temperature rises, the reaction speed also increases and gets out of control. The mixed acid must be cooled. However, metals, glass or other common materials for heat exchangers are not resistant to this mixed acid.
Task definition
The company was looking for an effective, metal-free and reliable heat exchanger for cooling, chemically resistant to a highly concentrated mixture of hydrofluoric and nitric acid for installation in wet benches.
Solution
This is where our shell and tube heat exchanger comes into play.
The mixed acid is circulated through a PVDF all-plastic heat exchanger and kept at temperature with cooling water.
Result
Wet benches with PVDF tube plate and tube bundle heat exchangers have been in use since 2006.
