Scraped surface heat exchangers (SSHE) are specialized heat transfer devices used in various industries for highly viscous or heat-sensitive products. They consist of a cylindrical shell with an internal rotor that scrapes the product off the heated surface as it rotates. This scraping action promotes efficient heat transfer and prevents product fouling or degradation. SSHEs are commonly used in food processing, pharmaceuticals, and other applications requiring precise temperature control and gentle handling of viscous products.
Q: What is a scraped surface heat exchanger (SSHE)?
A: A scraped surface heat exchanger is a heat transfer device designed for processing highly viscous or heat-sensitive products. It consists of a cylindrical shell with an internal rotor fitted with scraping blades. As the rotor rotates, the blades scrape the product off the heated surface, facilitating efficient heat transfer and preventing fouling or degradation.
Q: How does a scraped surface heat exchanger work?
A: A scraped surface heat exchanger operates by combining heat transfer and mechanical action. The product enters the heat exchanger and forms a thin film on the heated surface. The rotating blades of the internal rotor continuously scrape the product off the surface, promoting heat transfer and maintaining a consistent product film thickness. The heated product is then discharged, while the cooling medium (if applicable) maintains the desired temperature.
Q: What are the advantages of using scraped surface heat exchangers?
A: Scraped surface heat exchangers offer several advantages. They are particularly suited for handling highly viscous or heat-sensitive products that may foul or degrade in conventional heat exchangers. The scraping action promotes efficient heat transfer, prevents product fouling, and ensures consistent product quality. Scraped surface heat exchangers also allow for precise temperature control, gentle product handling, and reduced residence time, resulting in improved process efficiency.
Q: Where are scraped surface heat exchangers used?
A: Scraped surface heat exchangers are used in various industries, including food processing, pharmaceuticals, cosmetics, and specialty chemicals. They are commonly employed in applications involving the processing of viscous products, such as sauces, confectionery fillings, doughs, creams, polymers, waxes, and high-fat products. SSHEs are suitable for applications requiring precise temperature control, uniform product consistency, and gentle handling.
Q: Can scraped surface heat exchangers handle high-viscosity products?
A: Yes, scraped surface heat exchangers are specifically designed to handle high-viscosity products. The scraping blades of the internal rotor effectively agitate and remove the product from the heated surface, even in highly viscous conditions. This promotes efficient heat transfer and prevents product buildup or fouling, allowing for successful processing of high-viscosity materials.
Q: Are scraped surface heat exchangers suitable for heat-sensitive products?
A: Yes, scraped surface heat exchangers are well-suited for heat-sensitive products. The scraping action ensures gentle and controlled heat transfer, minimizing the risk of thermal degradation or product quality deterioration. The ability to maintain precise temperature control and short residence times further helps in processing heat-sensitive materials while preserving their desired properties.