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Blowdown Limit
Blowdown or Blowing down may refer to: * Windthrow or forest blowdown, a felling of trees by windstorm * Blowdown stack, a vertical containment structure at a refinery or chemical plant * Blowdown, a process plant controlled or emergency depressurization * Boiler blowdown, a steam-boiler process to remove impurities * '' Blowdown'', a television series focusing on explosive demolition * Diving bell or hyperbaric chamber blowdown (diving), the compression of the pressurised chamber atmosphere, or displacement of ambient pressure water by adding high pressure gas through a blowdown valve. * in mathematics, the inverse of blowing up In mathematics, blowing up or blowup is a type of geometric transformation which replaces a subspace of a given space with the space of all directions pointing out of that subspace. For example, the blowup of a point in a plane replaces the poin ... * "Blowing Down", song from the Digable Planets studio album '' Blowout Comb'' {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Windthrow
In forestry, windthrow refers to trees uprooted by wind. Breakage of the tree bole (botany), bole (trunk) instead of uprooting is called windsnap. Blowdown refers to both windthrow and windsnap. Causes Windthrow is common in all forested parts of the world that experience storms or high wind speeds. The risk of windthrow to a tree is related to the tree's size (height and diameter), the 'sail area' presented by its crown, the anchorage provided by its roots, its exposure to the wind, and the local wind climate. A common way of quantifying the risk of windthrow to a forest area is to model the probability or 'return time' of a wind speed that would damage those trees at that location. Another potential method is the detection of scattered windthrow based on satellite images. Tree senescence can also be a factor, where multiple factors contributing to the declining health of a tree reduce its anchorage and therefore increase its susceptibility to windthrow. The resulting dama ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Blowdown Stack
A blowdown stack is an elevated vent or vertical stack that is used to vent the pressure of components of a chemical, refinery or other plant if there is a process problem or emergency. A blowdown stack can be used to complement a flare stack or as an alternative. The purpose is to prevent 'loss of containment' of volatile liquids and gases. Blowdown from several systems may be combined in a blowdown header prior to the stack. A knock-out pot may be provided at the base of the stack to remove any liquids. Blowdown stacks may either be ignited (like a flare) or un-ignited (a ‘cold’ vent). The height of the blowdown stack must be tall enough to ensure the safe dispersal of vapour. Blowdown Blowdown is the controlled removal, safe flow and disposal of vapour from a pressure vessel. Blowdown, or depressurisation, removes hazardous inventory from a vessel, reduces the pressure in the vessel and thereby reduces the stresses in the vessel walls. Blowdown is used prior to draining ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Plant Process And Emergency Shutdown Systems
A process plant shutdown system is a functional safety countermeasure crucial in any hazardous process plant such as oil and gas production plants and oil refineries. The concept also applies to non-process facilities such as nuclear plants. These systems are used to protect people, assets, and the environment when process conditions get out of the safe design envelope the equipment was designed for. As the name suggests, these systems are not intended for controlling the process itself but rather for protection. Process control is performed by means of an independent process control systems (PCS) and should not be relied upon to execute critical safety actions. Although functionally separate, process control and shutdown systems are usually interfaced under one system, called an integrated control and safety system (ICSS). Shutdown systems typically use equipment that is SIL 2 certified as a minimum, whereas control systems can start with SIL 1. SIL applies to both hardwa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Boiler Blowdown
Boiler blowdown is water intentionally wasted from a boiler to avoid concentration of impurities during continuing evaporation of steam. The water is blown out of the boiler with some force by steam pressure within the boiler. Bottom blowdown used with early boilers caused abrupt downward adjustment of boiler water level and was customarily expelled downward to avoid the safety hazard of showering hot water on nearby individuals. Background A steam boiler evaporates liquid water to form steam, or gaseous water, and requires frequent replenishment of boiler feedwater Boiler feedwater is the water which is supplied to a boiler. The feed water is put into the steam drum from a feed pump. In the steam drum the feed water is then turned into steam from the heat. After the steam is used, it is then dumped to the ... for the continuous production of steam required by most boiler applications. Water is a capable solvent, and will dissolve small amounts of solids from piping and co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Blowdown (TV Series)
Blowdown is an internationally broadcast documentary television series that follows a team of explosive demolition experts as they prepare and implode iconic, complex and challenging structures around the world. The series airs on National Geographic Channel, National Geographic Channel International, History Television in Canada, DMAX (TV channel), DMAX in Germany and Five (TV channel), Five in the United Kingdom, and is produced by Parallax Film Productions Inc.. The hour-long shows focus on the dangers, challenges, and inside strategies of this type of demolition by documenting the work of a specialized explosives team: Controlled Demolition, Inc., Controlled Demolition Incorporated of Phoenix, Maryland, USA. Using a combination of exclusive footage, high-concept visual effects and process-driven computer models, Blowdown explains the complex science behind CDI’s mission. The series highlights obstacles the team encounters as they rely on experience and intuition to reve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Explosive Demolition
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An explosive charge is a measured quantity of explosive material, which may either be composed solely of one ingredient or be a mixture containing at least two substances. The potential energy stored in an explosive material may, for example, be: * chemical energy, such as nitroglycerin or grain dust * pressurized gas, such as a gas cylinder, aerosol can, or boiling liquid expanding vapor explosion * nuclear energy, such as in the fissile isotopes uranium-235 and plutonium-239 Explosive materials may be categorized by the speed at which they expand. Materials that detonate (the front of the chemical reaction moves faster through the material than the speed of sound) are said to be "high explosives" and materials that deflagrate are said to be " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Blowdown (diving)
A diving chamber is a vessel for human occupation, which may have an entrance that can be sealed to hold an internal pressure significantly higher than ambient pressure, a pressurised gas system to control the internal pressure, and a supply of breathing gas for the occupants. There are two main functions for diving chambers: * as a simple form of submersible vessel to transport divers underwater and to provide a temporary base and retrieval system in the depths; * as a land, ship or offshore platform-based hyperbaric chamber or system, to artificially reproduce the hyperbaric conditions under the sea. Internal pressures above normal atmospheric pressure are provided for diving-related applications such as saturation diving and diver decompression, and non-diving medical applications such as hyperbaric medicine. Also known as a Pressure vessel for human occupancy, or PVHO. The engineering safety design code is ASME PVHO-1. Basic types of diving chambers There are two basi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Blowing Up
In mathematics, blowing up or blowup is a type of geometric transformation which replaces a subspace of a given space with the space of all directions pointing out of that subspace. For example, the blowup of a point in a plane replaces the point with the projectivized tangent space at that point. The metaphor is that of zooming in on a photograph to enlarge part of the picture, rather than referring to an explosion. The inverse operation is called blowing down. Blowups are the most fundamental transformation in birational geometry, because every birational morphism between projective varieties is a blowup. The weak factorization theorem says that every birational map can be factored as a composition of particularly simple blowups. The Cremona group, the group of birational automorphisms of the plane, is generated by blowups. Besides their importance in describing birational transformations, blowups are also an important way of constructing new spaces. For instance, most proc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
