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Flow-through ventilation is the main ventilation circuit for the mine. Air enters the mine from the surface via a shaft, ventilation raise or adit.The air is distributed through the mine via internal ventilation raises and ramps, and flows are controlled by regulators and permanently mounted ventilation fans.
A heat gun comprises a source of heat, usually an electrically heated element or a propane/liquified petroleum gas, a mechanism to move the hot air such as an electric fan, unless gas pressure is sufficient; a nozzle to direct the air, which may be a simple tube pointing in one direction, or specially shaped for purposes such as concentrating the heat on a small area or thawing a pipe but not ...
Diagramatic operation of a thermal wheel Ljungström Air Preheater by Swedish engineer Fredrik Ljungström (1875–1964). A thermal wheel, also known as a rotary heat exchanger, or rotary air-to-air enthalpy wheel, energy recovery wheel, or heat recovery wheel, is a type of energy recovery heat exchanger positioned within the supply and exhaust air streams of air-handling units or rooftop ...
A centrifugal fan is a mechanical device for moving air or other gases in a direction at an angle to the incoming fluid. Centrifugal fans often contain a ducted housing to direct outgoing air in a specific direction or across a heat sink; such a fan is also called a blower, blower fan, or squirrel-cage fan (because it looks like a hamster wheel).
Schematic diagram illustrating a 2-spool, high-bypass turbofan engine with an unmixed exhaust. The low-pressure spool is coloured green and the high-pressure one purple. Again, the fan (and booster stages) are driven by the low-pressure turbine, but more stages are required. A mixed exhaust is often employed.
The axial fan is often contained within a short section of cylindrical ductwork, to which inlet and outlet ducting can be connected. Axial fan types have fan wheels with diameters that usually range from less than a foot (0.3 meters) to over 30 feet (9.1 m), although axial cooling tower fan wheels may exceed 82 feet (25 m) in diameter.
What one nurse learned about humanity amidst the Ebola epidemic
Mechanical fans can be used to provide positive pressure ventilation by breaking or removing windows, skylights or heat/smoke vents on the roof; or by cutting new exhaust vents in the building. If there is no suitable existing hole, firefighters may use their equipment to make one, such as specialized saws for cutting a large hole in the roof.