Twister Supersonic Separator
Encyclopedia
The Twister Supersonic Separator is a compact tubular device which is used for the removing water and/or hydrocarbon dewpointing of natural gas
. The principle of operation is similar to the near isentropic Brayton cycle
of a turboexpander. The gas is accelerated to supersonic velocities within the tube using a De Laval nozzle
and inlet guide vanes spin the gas around an inner-body which creates the "ballerina effect" and centrifugally separates the water and liquids in the tube. Hydrate
s do not form in the Twister tube due to the very short residence time of the gas in the tube (around 2 millisecs). A secondary separator treats the liquids and slip gas and also acts as a hydrate control vessel. Twister is able to dehydrate to typical pipeline dewpoint specifications and relies on a pressure drop from the inlet of about 25%, dependent on the performance required. The fundamental mathematics behind supersonic separation can be found in the Society of Petroleum Engineers paper (number 100442) entitled " Selective Removal of Water from Supercritical Natural Gas". The closed Twister system enables subsea gas treatment subsea
.
It is a product of Twister BV, a Dutch firm affiliated with Royal Dutch Shell
.
Natural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...
. The principle of operation is similar to the near isentropic Brayton cycle
Brayton cycle
The Brayton cycle is a thermodynamic cycle that describes the workings of the gas turbine engine, basis of the airbreathing jet engine and others. It is named after George Brayton , the American engineer who developed it, although it was originally proposed and patented by Englishman John Barber...
of a turboexpander. The gas is accelerated to supersonic velocities within the tube using a De Laval nozzle
De Laval nozzle
A de Laval nozzle is a tube that is pinched in the middle, making a carefully balanced, asymmetric hourglass-shape...
and inlet guide vanes spin the gas around an inner-body which creates the "ballerina effect" and centrifugally separates the water and liquids in the tube. Hydrate
Hydrate
Hydrate is a term used in inorganic chemistry and organic chemistry to indicate that a substance contains water. The chemical state of the water varies widely between hydrates, some of which were so labeled before their chemical structure was understood....
s do not form in the Twister tube due to the very short residence time of the gas in the tube (around 2 millisecs). A secondary separator treats the liquids and slip gas and also acts as a hydrate control vessel. Twister is able to dehydrate to typical pipeline dewpoint specifications and relies on a pressure drop from the inlet of about 25%, dependent on the performance required. The fundamental mathematics behind supersonic separation can be found in the Society of Petroleum Engineers paper (number 100442) entitled " Selective Removal of Water from Supercritical Natural Gas". The closed Twister system enables subsea gas treatment subsea
Subsea
Subsea is a general term frequently used to refer to equipment, technology, and methods employed in marine biology, undersea geology, offshore oil and gas developments, underwater mining, and offshore wind power industries.- Oil and gas :...
.
It is a product of Twister BV, a Dutch firm affiliated with Royal Dutch Shell
Royal Dutch Shell
Royal Dutch Shell plc , commonly known as Shell, is a global oil and gas company headquartered in The Hague, Netherlands and with its registered office in London, United Kingdom. It is the fifth-largest company in the world according to a composite measure by Forbes magazine and one of the six...
.