Patent Model for Multiple Effect Vacuum Evaporator
tin, wood, paint, and red cloth ribbon
August 25, 1843
Norbert Rillieux (1806-1894), a free black man, invented the first successful multiple effect vacuum process for producing sugar. Born and raised in New Orleans, Rillieux was sent by his wealthy parents to engineering school in Paris. Young Rillieux was an outstanding student and after graduating from L'Ecole Centrale, taught at the school. Rillieux soon became interested in the processes of thermal dynamics and steam power. By 1830 he was already experimenting with a multiple effect vacuum evaporator. He returned to New Orleans from France and developed a vacuum evaporator specifically designed for processing sugar from sugar cane.
It took him several years to convince local planters to try it. A first effort at the plantation of Zenon Ramon in 1834 never got off the ground, but in 1843 Rillieux installed his system on the "Myrtle Grove" plantation owned by Theodore Packwood. By 1844 the widely known manufacturers Merrick & Towne in Philadelphia were offering planters a selection of three different vacuum evaporator systems. Planters were able to select systems capable of producing 6000, 12,000, or 18,000 pounds of sugar per day. In 1846 Rillieux was able to convince several planters to install them on the sugar factories on their plantations. The vacuum evaporators proved so efficient that planters were able to cover the costs of the new equipment with the expanded profits from the sugar cane processed under Rillieux's system. Promotional testimonials included those from planters Judah P. Benjamin and Theodore Packwood.
This patent model shows two vacuum containers or pans. In practice three or even four could be used with Rillieux's system. Today multiple effect vacuum evaporation is used in processing food products and other industrial products.
Finely wrought and full of information, patent models are educational and fun to collect, but hard to find. The first U.S. patent law passed in 1790 required that each inventor submit a detailed model of the invention along with the patent drawing and application. In the late 1800s a series of patent laws eliminated the models. But even before that time two major fires in the Patent Office (1836 and 1877) destroyed almost a hundred thousand of the models. This Rilliuex model is one that survived.
The item was donated by Bert Vorchheimer and Carol Wertheimer Vorchheimer in 1993.