Patent Model, Multiple Effect Vacuum Evaporator

Norbert Rillieux (1806-1894) sent this scale model of the Multiple Effect Vacuum Evaporator to the US Patent Office when he applied for, and received, his first patent in 1843. Reillieux’s invention would revolutionize the sugar industry. The model’s two cylinders represent enclosed vacuum chambers in which to boil sugarcane. Steam captured from the boiling syrup provided power to boil more sugarcane. As production grew, prices dropped and white sugar went from a luxury to a staple. However, demand for sugar sparked a massive increase in another system, slavery. More enslaved Africans came to labor in the cane fields. Born in New Orleans to a free African American woman and a wealthy white engineer, Rillieux designed the multiple-effect vacuum evaporation system while studying engineering in Paris in 1830. His method remains in use for processing food and industrial products. Patent models are rare due to two major fires at the US Patent Office. Rillieux’s model survived and was featured in The Real McCoy, an exhibition on African American inventions designed to encourage creativity in young people in 1989.