Cascade storage system

Cascade storage system

A cascade storage system is a cascade storage tank system which is used for the refilling of smaller compressed gas cylinders or air cylinders. Each of the large cylinders will be filled by a compressor, but the cascade system allows small cylinders to be filled without the presence of a compressor. In addition, a cascade system is useful as a "reservoir" to allow a low-capacity compressor to meet the demand of filling several small cylinders in succession.

In general rupture discs are installed inline between the compressor and the storage units to rupture if the maximum safety pressure is reached.

Principle of operation

When gas contained in a cylinder at high pressure is allowed to flow to another cylinder containing gas at a lower pressure, the pressures will equalise to a value somewhere between the two initial pressures. An example could be a 100 litre (internal volume) cylinder pressurised to 200 bar filling a 10 litre (internal volume) cylinder which was unpressurised resulting in both cylinder equalising to approximately 180 bar. If another 100 litre cylinder pressurised this time to 250 bar were then used to "top-up" the 10 litre cylinder, both of these cylinders would equalise to about 240 bar. However, if the higher pressure 100 litre cylinder were used first, the 10 litre cylinder would equalise to about 225 bar and the lower pressure 100 litre cylinder could not be used to top it up. In a cascade storage system, several large cylinders are used to bring a small cylinder up to a desired pressure, by always using the cylinder with the lowest pressure first, then the cylinder with the next lowest pressure, and so on.

Uses

Breathing sets

A breathing set may be filled to its working pressure by decanting from big (often blowtorch-sized) cylinders. (To make this easy the neck of the cylinder of the Siebe Gorman Salvus rebreather had the same thread as a blowtorch oxygen cylinder, but the opposite gender, for direct decanting.) The large cylinders are available in a variety of sizes, typically from 50 litre internal capacity to well over 100 litres. [ [http://www.airproducts.com/NR/rdonlyres/7CCE748B-35BA-45B2-93D4-48AE3D3EEDF3/0/reference_cylinder_information.pdf Specialty Gas Cylinder Dimensions] Air Products]

The big cylinders are put into an order of ascending pressure, say A B C, etc. The small cylinder to be filled is connected to big cylinder A, then the gas is allowed to flow into the small cylinder. This is repeated with B, then C, etc., until the small cylinder is as full as needed or as full as possible. The result is that A drains faster than B, which drains faster than C; A is used for the first bulk of the filling of the small cylinder, which is then topped up from B, then from C, which keep a higher pressure for longer.

Hydrogen storage

In cascade storage systems for hydrogen storage, as for example at hydrogen stations, fuel dispenser A draws hydrogen from tank A, while dispenser B draws fuel from hydrogen tank B. If dispenser A is over-utilized, tank A will become depleted before tank B. At this point the dispenser A is switched to tank C. Tank C will then supply dispenser A and B and tank A until tank A is filled to the same pressure as tank B and the dispensers are disconnected, after which the control system will close the control valves to switch to its former state. [ [http://www.hydrogencontest.org/pdf/UMissouri_2004.pdf Hydrogen Fueling Station Pag 4.] ]

References


Wikimedia Foundation. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • Cascade — A cascade is a type of waterfall or a series of waterfalls.Cascade may also refer to: Places North America* Cascade Range, a mountain range on the west coast of North America * Cascade Volcanoes, a grouping of volcanoes on the west coast of North …   Wikipedia

  • Storage tank — A storage tank is a container, usually for holding liquids, sometimes for compressed gases (gas tank). The term can be used for both reservoirs (artificial lakes and ponds), and for manufactured containers. The usage of the word tank for… …   Wikipedia

  • Hydrogen storage — describes the methodologies for storing H2 for subsequent use. The methodologies span many approaches, including high pressures and cryogenics, but usually focus on chemical compounds that reversibly release H2 upon heating. Hydrogen storage is a …   Wikipedia

  • Cascade Range — Geobox|Range name=Cascade Range other name=The Cascades image size=280 image caption=Mount Rainier in Washington state country=United States| country1=Canada state= Oregon state1= Washington state2= California state3= British Columbia state… …   Wikipedia

  • system — 1. [TA] A consistent and complex whole made up of correlated and semiindependent parts. A complex of functionally related anatomic structures. 2. The entire organism seen as a complex organization of parts. 3. Any complex of structures… …   Medical dictionary

  • Versioning file system — A versioning file system is any computer file system which allows a computer file to exist in several versions at the same time. Thus it is a form of revision control. Most common versioning file systems keep a number of old copies of the file.… …   Wikipedia

  • Pacific mountain system — ▪ mountains, North America Introduction  series of mountain ranges that stretches along the Pacific coast (Coast Ranges) of North America from northern British Columbia (Canada) to northwestern Mexico. They run for some 4,500 miles (7,250… …   Universalium

  • Hydrogen station — A hydrogen station is a storage or filling station for hydrogen, usually located along a road or hydrogen highway, or at home as part of the distributed generation resources concept. Vehicles use hydrogen as fuel in one of several ways, including …   Wikipedia

  • Squad truck — A Squad Truck is a piece of rescue apparatus specifically designed to transport the necessary tools, equipment, and personnel to perform a vehicle extrication at the scene of an entrapment. Vehicle Construction The design of squad trucks varies,… …   Wikipedia

  • East Meadow Fire Department — InfoboxFireDepartment name = East Meadow Fire Department motto = established = 1922 annual calls = staffing = Approx. 250 Members strength = stations = 5 (and 2 offices) engines = 5 trucks = 2 squads = rescues = 1 bulldozers = airplanes =… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”