Ventilating fans

When a fan is placed at the end of a system so that most of the system pressure drop is on the suction side of the fan, it is commonly called an exhaust fan or an exhauster. This term may also be appHed to a ventilating fan where the primary function is to exhaust air from a room or an open hood. 

Uses. In architectural and industrial appHcations vibrational isolators are used to reduce transmission of vibration into building stmctures from rotating or reciprocating machinery, such as ventilating fans, pumps, chillers, industrial machinery, and the piping and ductwork coimected to this equipment (6). Vibration isolators also can be used to isolate vibration-sensitive equipment or noise-sensitive areas from sources of vibration. Examples are special pneumatic isolators to protect electron microscopes, and isolators used to support floating concrete floors in recording studios. 

TEFC motors have both an internal fan for circiilating air within the motor and an external fan for forcing the air through or over the motor frame or heat exchanger. Small motors [approximately 2.238 kW (3 hp) and below] do not require ventilating fans these totally enclosed nonventilated motors are similar to TEFC with the fans omitted. 

Combustible gas detection systems are frequently used in areas of poor ventilation. By the early detection of combustible gas releases before ignitible concentration levels occur, corrective procedures such as shutting down equipment, deactivating electrical circuits and activating ventilation fans can be implemented prior to fire or explosion. Combustible gas detectors are also used to substantiate adequate ventilation. Most combustible gas detection systems, although responsive to a wide range of combustible gases and vapors, are normally calibrated specifically to indicate concentrations of methane since most natural gas is comprised primarily of methane. 

In another building, gusting winds caused transient increases in pressure that tripped the ventilation fans. The problem was overcome by increasing the fan speeds. Unfortunately the increased flow of cold air through a doorway cooled a fire water main so much that it froze and cracked [21 ]. 

Ventilator, m. ventilator, fan, blower. Ventil-deckel, m. valve lid, valve cover, -elmer, m. -eimerchen, n. valved container (for vis cous liquids), -gehtiuse, n. valve chamber, ventilieren, v.t. ventilate. 

VENTILATING FANS FOR MINES a TUNNELS, ETC. EXHAUSTERS FOR LOW VACUUM SERVICE... 

Noise. Noise is another environmental factor to be considered. It does not have to be very loud to seriously affect worker performance if it is persistent. The source of noise disturbance may be one of many things—plant equipment, heavy traffic outside, ventilation fans, etc. 

The filter unit was located entirely inside the respective buildings and was independent of the ventilation system. The unit consisted of a suction box (usually floor standing) to which the filter material was attached usually as a flat vertical surface of an area to give a face velocity of about 0.75 m/s. Dust collected on this surface and was removed with a vacuum cleaner. Cleaned air was directed into an overhead discharge duct with a permeable lower surface. The capacity of the fan in the filter unit was made the same order as that of the main ventilating fan. The overhead duct was located above and as near to the stock as possible so that the clean air flowed downwards towards the stock. This air did not cause a draught because it was discharged at a low speed (0.3 m/s) and as it was recirculated it was at the same temperature as the air in the room. 

Casings, caps, framework of ventilation, fan blades, air filters, filters and pumps of industrial dishwashers, softeners, washing machines, detergent product vats, parts of pumps used for handling chemicals, frames, rollers of cables, parts with film hinge, electrical components, translucent parts, cases, pipes. .. 

Polypropylenes are cost-effective polymers for casings, caps, framework of ventilation, fan blades, air filters, filters and pumps of agricultural machines, pipes. .. 

Potatoes harvested luider wet soil conditions should be dried immediately. Drying involves removal of water present on the outside of the potato or in the soil on the potatoes in order to eliminate conducive conditions for the multiplication of microorganisms and to prevent the spread of rot and other storage diseases (Sijbring, 1987). The ventilation fan should run continuously during this phase while the average potato pile temperature is allowed to settle... 

The application of semiconductor gas sensors (mainly the Sn02 sensor) is ever expanding into various fields, domestic and industrial, as shown in Figure 3. Examples are the CO selective sensor and combustion monitor sensor, which are applicable to micro wave ovens or ventilation fans, kerosene or gas stoves, hot water supply systems, and so on. 

Be certain there is adequate ventilation and that ventilator fans are turned on. Toning takes place under normal working fights so there is no reason not to open the door. 

By responding to fumes in cooking areas, car parks, laboratories and similar places, gas sensors can be used to control ventilation fans. In industrial situations the sensor can monitor concentrations of carbon monoxide, ammonia, solvent vapours, hydrocarbon gases, ozone etc., and because of the growing consciousness of environmental pollution and the safety aspects of industrial processes the applications will multiply. 

Investigators learned that one afternoon, a contractor entered the area to start a local ventilation fan in preparation for an unrelated nearby maintenance job. The electrical switch used to start the pump was identical to the type of switch used to start the ventilation fan. Although the switch was labeled, the tag was hard to read. These switches were over 50 feet from the outdoor caustic soda pump installation, well outside of the diked area. The pump continued to run, unnoticed by anyone. There was no instrument in an occupied location indicating that the pump was running. [12]... 

Most detection systems are designed not only to report the presence of hazardous fumes through instrument readouts but to sound an alarm and automatically initiate corrective or protective action. In an office or shop, for example, the system can be designed to shut down all ventilating fans and close exterior air inlet dampers. 

During our inspection, we noted that most of the fume hoods were in a state of serious disrepair. We found units that were missing interior panels and covers and as a result leaked contaminants. We found hoods with malfunctioning or inoperative ventilation fans. We also observed hoods vented through duct work that was perforated. Finally, we also found... 

If the unit will be indoors in a more controlled environment, then other factors need to be considered such as ventilation. Ventilation can be addressed through the use of gas cabinets and ventilating fans. 

Locate ventilation fans and hoist houses to minimize the effects of noise on wildlife and humans living nearby. 

Several factors are believed to have contributed to this tragic accident. These included the overfilling and aggressive mixing of the liquid manure tank contents, inadequate ventilation with only one of the six ventilation fans in use and the placement of the storage tank below and not outside the shed. 

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