A scraped surface heat exchanger comprising a heat exchanger surface, a rotating shaft having at least one mounting means, and a scraping element, wherein the scraping element engages with the mounting means. In a scraped surface heat exchanger comprising a blade having two openings, the scraping element being connected to the mounting means, when the rotating shaft rotates relative to the heat exchanger surface, A scraped surface heat exchanger characterized in that the scraping element does not substantially move with respect to the rotating shaft and the scraping element does not substantially contact the inner surface of the heat exchanger. [Selection] Figure 2