A scraped surface heat exchanger comprising a heat exchange surface, a rotatable shaft, said shaft having at least one mounting means, and a sweeping element wherein said sweeping element comprises, a blade having at least one aperture for engaging with the mounting means such that the sweeping element is connected to the mounting means and characterised in that when the rotatable shaft is rotating relative to the heat exchange surface the sweeping element has substantially no movement relative to the rotating shaft and said sweeping element has substantially no contact with the inner surface of the heat exchanger.
