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History of hydrocyclones development

Hydrocyclone E.Bretney

The idea of using centrifugal forces for separation reasons was used for the first time for dust removal in air. In 1885 fist patents were given for such devices (air cyclones) to Knickerbocker company, USA.

In 1891 E.Bretney obtained the first patent for hydrocyclone - predecessor of all contemporary hydrocyclones. The Bretney cyclone was designed with a closed apex for intermittent discharge and was the forerunner to present-day desanders that are used for separating sand from water in pressurized water systems. The Bretney cyclone had a roof entry feed inlet that canted downd into the main cyclone body. The first hydrocyclone was a crude, unlined, mild steel cyclone, but it paved the way for bigger and better things to come.

Between 1891 and 1939 a number of patents were granted on hydrocyclones, but the records show very few commercial installations. One of the earliest references to a commercial istallation during this time was a cyclone 1.6 m in diameter that was installed in a U.S. phosphate plant in 1914.

Only in 1939, Dutch State Mines (DSM) started investigating the use of hydrocyclones for the cleaning of coal. The first use of hydrocyclones by DSM was to dewater the sand used to make up suspensions for heavy-medium separators. Around the same time, the Powell Duffren Company in the United Kingdom was looking at using hydrocyclones for dewatering coal ahead of screens, and obtained a patent for a hydrocyclone in which apes sections could be replaced to overcome abrasion.

The most prolific period for the development of the development of the hydrocyclones occurred from 1939 to 1948, when M.G. Driessen of DSM led the effort to develop the use of cyclones in coal preparation. The main applications investigated during that time were the dewatering of sand suspension and the actual cleaning of coal from sand using the sand suspension. Driessen obtained many patents and published numerous papers, which fueled a worldwide interest in the commercialization of cyclones. Many people started using hydrocyclones for clarifying water, removing solids from drilling mud, and for mineral concentration. In 1944, Humphrey Investment Company, using Driessen's published works, developed a Humphrey centrifuge - the first large-diameter commercial hydrocyclone with a vortex finder, used to dewater mineral slurries ahead of Humphrey spiral. Ironically, the original DSM hydrocyclones did not have vortex finders, and it was not until 1948 that the commercial DSM hydrocyclones incorporated these.

The DSM patents were commercialized by Stamicarbon N.V., which licensed the technology to companies such as Dorr Company (later - Dorr Oliver Company) for minerals and Heyl Patterson for coal.

The Dorr Company started marketing the Dorrclone in 1948. Stamicarbon continued research on the cyclone and in 1948 filed for the first known patent on the use of conventional hydrocyclones for separating liquids and also for a patent on the use of an adjustable elastomer apex. As the awareness of hydrocyclones started to rise, other manufacturing companies besides the Dorr Company started looking at he cyclone as a viable product. In 1948, American Cyanamid started experimenting with a small-diameter DSM cyclone fro a heavy-medium coal separation and continued this work until 1950 when it turned over the designs and work to Kelly Krebs. Krebs has retired from American Cyanamid ad started his own company, Krebs Engineers, in San Francisco, California.

Although the Dorr Company and other manufacturers pioneered the use of cyclones for closed-circuit grinding, it was Equipment Engineers (later Krebs Engineers) that eventually took the market away from Dorr Oliver. Also, Krebs in 1055 started to make hydrocyclones with evolvent inlet and rubber linings.

It is necessary to notice that the basic design of hydrocyclones considerably has not changed since 50th years of the XX-th century. In the USSR mass production of hydrocyclones has begun in 1959.