chemical engineering Chemical engineering is an engineering field which deals with the study of the operation and design of chemical plants as well as methods of improving production. Chemical engineers develop economical commercial processes to convert raw materials ...

, a cascade is a

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

consisting of several similar stages with each processing the output from the previous stage. Cascades are most commonly used in

isotope separation Isotope separation is the process of concentrating specific isotopes of a chemical element by removing other isotopes. The use of the nuclides produced is varied. The largest variety is used in research (e.g. in chemistry where atoms of "marker" n ...

distillation Distillation, also classical distillation, is the process of separating the component substances of a liquid mixture of two or more chemically discrete substances; the separation process is realized by way of the selective boiling of the mixt ...

, flotation and other separation or purification processes.

Cascade process

Cascade process is any process that takes place in a number of steps, usually because the single step is too inefficient to produce the desired result. For example, in some uranium-enrichment processes the separation of the desired

isotope Isotopes are distinct nuclear species (or ''nuclides'') of the same chemical element. They have the same atomic number (number of protons in their Atomic nucleus, nuclei) and position in the periodic table (and hence belong to the same chemica ...

is only poorly achieved in a single stage; to achieve better separation the process has to be repeated a number of times, in a series, with the enriched fraction of one stage being fed to the succeeding stage for further enrichment. Another example of cascade process is that operating in a cascade liquefier.oxford dictionary of science, 4th edition, 1999.

Examples

If a

still A still is an apparatus used to distillation, distill liquid mixtures by heating to selectively Boiling, boil and then cooling to Condensation, condense the vapor. A still uses the same concepts as a basic Distillation#Laboratory_procedures, ...

removes 99% of impurities from water (leaving .01 the original amount of impurities), a cascade of three stills will leave (1-0.99)³ = 0.000001 = 0.0001% the amount of impurities (99.9999% removed).

References

{{DEFAULTSORT:Cascade (Chemical Engineering) Chemical process engineering