Fachgebiet Elektronik und Elektrotechnik, Mechanische Industrie, Bauindustrie und öffentliches Bauwesen
en
Definition a fan supplying ventilating air under pressure
Quelle SEC:Chambers,Dict.of Science and Technology

Terminus pressure fan
Zuverlässigkeit 3 (Zuverlässig)
Quelle How to use a Positive Pressure Fan.Positive Pressure Ventilation Guidelines,05/11/97
Datum 26/11/2014

Terminus forced draft fan
Zuverlässigkeit 3 (Zuverlässig)
Quelle SEC:UCPTE
Regionaler Gebrauch US
Datum 26/11/2014

Terminus forced draught fan
Zuverlässigkeit 3 (Zuverlässig)
Quelle UCPTE
Regionaler Gebrauch UK
Datum 26/11/2014

de
Terminus Geblaese
Zuverlässigkeit 3 (Zuverlässig)
Quelle UCPTE
Datum 26/11/2014

Terminus Druckgeblaese
Zuverlässigkeit 3 (Zuverlässig)
Quelle UCPTE;CNE
Datum 26/11/2014
http://iate.europa.eu/SearchByQuery.do?method=searchDetail&l...

Fachgebiet Mechanische Industrie, Materialtechnologie
en
Terminus blowing ventilator
Zuverlässigkeit 3 (Zuverlässig)
Datum 24/09/2003

Terminus forced-draft blower
Zuverlässigkeit 3 (Zuverlässig)
Datum 24/09/2003

de
Terminus Einblasventilator
Zuverlässigkeit 3 (Zuverlässig)
Anmerkung Einblasventilator (plur Einblasventilatoren)
Datum 24/09/2003

Terminus Hauptluftgeblaese
Zuverlässigkeit 3 (Zuverlässig)
Anmerkung Einblasventilator (plur Einblasventilatoren)
Datum 24/09/2003

Terminus Pressluftgeblaese
Zuverlässigkeit 3 (Zuverlässig)
Anmerkung Einblasventilator (plur Einblasventilatoren)
Datum 24/09/2003

Terminus Frischluftgeblaese
Zuverlässigkeit 3 (Zuverlässig)
Anmerkung Einblasventilator (plur Einblasventilatoren)
Datum 24/09/2003

Terminus Pressluftventilator
Zuverlässigkeit 3 (Zuverlässig)
Anmerkung Einblasventilator (plur Einblasventilatoren)
Datum 24/09/2003
http://iate.europa.eu/SearchByQuery.do?method=searchDetail&l...

Gegensatz:

The combustion products are taken with induced draft fan via the regenerative flue gas heater (REGAVO) to the selective catalytic reduction (SCR) System. huc-vgu.de
Die Rauchgase werden mit Hilfe des Saugzuggebläses über den REGAVO zur SCR (Selective Catalytische Reduktion)-Anlage geführt. huc-vgu.de
http://www.linguee.de/deutsch-englisch/search?source=auto&qu...

Explanation of terminology

FDF: Abbreviation for Forced Draft Fan
IDF: Abbreviation for Induced Draft Fan
PAF: Abbreviation for Primary Draft Fan
BUF: Abbreviation for Boost Up Fan (desulfurizer draft fan)
GRF: Abbreviation for Gas Recirculation Fan
DWC: Abbreviation for Drywell Cooler
http://www.hitachi.com/businesses/infrastructure/product_sol...

In a fully-fired combined plant, exhaust gas of the gas turbine is used as combustion air for the boiler. Therefore, a gas turbine exhaust gas line is connected with boiler gas and air ducts. In particular, in case the gas turbine exhaust gas line is connected with the boiler air duct or a boiler air feed line on the outlet side of a forced draft fan provided thereon, when the gas turbine is stopped during a boiler independent operation and maintenance and inspection of the gas turbine are practiced, the gas turbine exhaust gas line and the air feed line are separated by separation means such as a damper.
https://www.google.ch/patents/US5697210


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Note added at 20 hrs (2016-09-23 16:50:44 GMT)
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Forced Draft & Induced Draft Cooling Towers Process
Cooling tower fans are used on induced draft cooling towers to pull air up through the fill media. On forced draft cooling towers, the air is pushed/forced by blowers at the bottom of the air inlet louver.
http://www.coolingtowerproducts.com/blog/how-cooling-towers-...

Principle of Circular Cooling Towers with Forecd Draft Fans
The hyperbolic shell achieves a natural draft effect which supports the fans arranged around the circumference of the cooling tower shell. Therefore the power consumption of the fans is reduced. The cooling tower is separated in different sections, which can be isolated, to ensure operation with lower water quantities. Also maintenance activities can be accomplished in shut-off sections while the rest of the cooling tower is still in operation.
http://spxcooling.com/products/round-forced-draft

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Cooling towers


COOLING TOWERS INTRODUCTION

The machines and processes of industry, as well as those devoted to human comfort and well being generated tremendous amounts of heat, which must be continuously, dissipated if those machines and processes are to continue to operate efficiency. Although this heat is usually transferred to a cool, flowing volume of water, final rejection is always to the atmosphere and, invariably, is accomplished by some form of heat exchanger.

The natural process of evaporation makes them very effective heat transfer mediums, although somewhat inefficient due to their limited surface area and their total dependence upon random winds.

TYPES OF COOLING TOWERS

Cooling towers are designed and manufactured in several types:

ATMOSPHERIC
MECHANICAL DRAFT
a. FORCED DRAFT

b. INDUCED DRAFT

HYBRID DRAFT
TYPED BY AIR FLOW
a. COUNTERFLOW

b. CROSSFLOW

a.1 DOUBLE-FLOW

a.2 SINGLE-FLOW

c. SPRAY-FILLED

TYPED BY CONSTRUCTION
a. FIELD-ERECTED

b. FACTORY-ASSEMBLED

TYPED BY SHAPE
a. RECTILINEAR

b. ROUND MECHANICAL DRAFT (RMD)

TYPED BY METHOD OF HEAT TRANSFER
a. EVAPORATIVE

b. DRY TOWER

c. PLUME ABATEMENT

d. WATER CONSERVATION

ATMOSPHERIC
The atmospheric cooling towers utilize no mechanical fan to create air flow through the tower, its air is derived from a natural induction flow provided by a pressure spray.

We can see it in the following picture:



MECHANICAL DRAFT
Mechanical draft towers uses fans (one or more) to move large quantities of air through the tower. They are two different classes:

Forced draft cooling towers
Induced draft cooling towers
The air flow in either class may be crossflow or counterflow with respect to the falling water. Crossflow indicates that the airflow is horizontal in the filled portion of the tower while counterflow means the air flow is in the opposite direction of the falling water.

The counterflow tower occupies less floor space than a crossflow tower but is taller for a given capacity. The principle advantages of the crossflow tower are the low pressure drop in relation to its capacity and lower fan power requirement leading to lower energy costs.

All mechanical towers must be located so that the discharge air diffuses freely without recirculation through the tower, and so that air intakes are not restricted. Cooling towers should be located as near as possible to the refrigeration systems they serve, but should never be located below them so as to allow the condenser water to drain out of the system through the tower basin when the system is shut down.

FORCED DRAFT

The forced draft tower, shown in the picture, has the fan, basin, and piping located within the tower structure. In this model, the fan is located at the base. There are no louvered exterior walls. Instead, the structural steel or wood framing is covered with paneling made of aluminum, galvanized steel, or asbestos cement boards.



During operation, the fan forces air at a low velocity horizontally through the packing and then vertically against the downward flow of the water that occurs on either side of the fan. The drift eliminators located at the top of the tower remove water entrained in the air. Vibration and noise are minimal since the rotating equipment is built on a solid foundation. The fans handle mostly dry air, greatly reducing erosion and water condensation problems.

INDUCED DRAFT

The induced draft tower show in the following picture has one or more fans, located at the top of the tower, that draw air upwards against the downward flow of water passing around the wooden decking or packing. Since the airflow is counter to the water flow, the coolest water at the bottom is in contact with the driest air while the warmest water at the top is in contact with the moist air, resulting in increased heat transfer efficiency.
Learn more: http://www.lenntech.com/cooling-towers.htm#ixzz4L6AkrldR
http://www.lenntech.com/cooling-towers.htm

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Note added at 2 days14 hrs (2016-09-25 10:43:12 GMT)
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Der Vollständigkeit halber habe ich noch den von elboliov angeführten Wikipedia-Artikel ausführlicher zitiert und einen weitern für Kühltürme angehängt:

Ein Ventilator (von lat. ventilare „Wind erzeugen“, „Kühlung zufächeln“) ist eine fremd angetriebene Strömungsmaschine, die meist mittels eines in einem Gehäuse rotierenden Laufrads ein gasförmiges Dispersionsmedium fördert und verdichtet sowie dabei zwischen Ansaug- und Druckseite ein Druckverhältnis zwischen 1 und 1,1 erzielt. Maschinen mit einem Druckverhältnis zwischen 1,1 und 3 sind Gebläse. Ventilatoren und Gebläse werden auch als Lüfter bezeichnet, insbesondere wenn sie zur Luftabsaugung vorgesehen sind. Im weiteren Sinn werden alle zu den Verdichtern gerechnet. Verdichter im engeren Sinn erzielen dagegen Druckverhältnisse von mehr als 3. Im Verhältnis zur Leistung erzielen Ventilatoren aufgrund des niedrigen Druckverhältnisses hohe Volumenströme, Gebläse wegen des mittleren Druckverhältnisses mittlere Volumenströme.
:
Axialventilatoren sind die gebräuchlichste Bauform. Die Drehachse des Axiallaufrads verläuft parallel bzw. axial zum Luftstrom. Die Luft wird durch das Axiallaufrad ähnlich wie bei einem Flugzeug- oder Schiffspropeller bewegt. Die Vorteile von Axialventilatoren sind die im Verhältnis zum hohen geförderten Luftdurchsatz geringen Abmessungen. Der Nachteil ist die geringere Druckerhöhung im Verhältnis zum Radialventilator
https://de.wikipedia.org/wiki/Ventilator

Breite und Höhe sind dabei von der geforderten Kühlleistung abhängig, diese kann bei Großkraftwerken deutlich mehr als 4 GW betragen. Mit dieser Wärmemenge werden im zugehörigen Kühlturm etwa 1500 Kilogramm Wasser in der Sekunde in Wasserdampf umgewandelt. Bei kleinen Anlagen werden zur Erhöhung der Effektivität zusätzlich Lüfter zur erhöhten Förderung des Luftstroms eingesetzt.
:
Ventilatorkühltürme (Höhe 34–100 Meter) sind nicht so hoch wie Naturzugkühltürme (Höhe bis zu 200 m), da der Luftzug mit Ventilatoren erzeugt wird. Auch Zellenkühler sind Ventilatorkühltürme, allerdings deutlich niedriger und kompakter.
Die ventilatorunterstützten runden Kühltürme (Teilnaturzug) kombinieren die Vorteile von Naturzugkühltürmen (kein Stromverbrauch durch kompletten Naturzug) mit denen von Zellenkühlern (bessere Kühlcharakteristik im Sommer sowie bessere betriebliche Flexibilität) und werden eingesetzt, wenn die Bauhöhe durch Nähe zu Wohnbebauung oder zum Schutz des Landschaftsbilds begrenzt ist.
Ventilatorunterstützte Kühltürme werden sowohl für den Industrie- als auch für den Kraftwerksbereich eingesetzt für Kühlwasserkreisläufe zwischen 25.000 und 200.000 m³/h.
https://de.wikipedia.org/wiki/Kühlturm

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Note added at 2 days14 hrs (2016-09-25 10:47:16 GMT)
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Und den verlinkten englischsprachigen Wikipedia-Artikel dazu:

With respect to drawing air through the tower, there are three types of cooling towers:
• Natural draft — Utilizes buoyancy via a tall chimney. Warm, moist air naturally rises due to the density differential compared to the dry, cooler outside air. Warm moist air is less dense than drier air at the same pressure. This moist air buoyancy produces an upwards current of air through the tower.
• Mechanical draught — Uses power-driven fan motors to force or draw air through the tower.
o Induced draught — A mechanical draft tower with a fan at the discharge (at the top) which pulls air up through the tower. The fan induces hot moist air out the discharge. This produces low entering and high exiting air velocities, reducing the possibility of recirculation in which discharged air flows back into the air intake. This fan/fin arrangement is also known as draw-through.
o Forced draught — A mechanical draft tower with a blower type fan at the intake. The fan forces air into the tower, creating high entering and low exiting air velocities. The low exiting velocity is much more susceptible to recirculation. With the fan on the air intake, the fan is more susceptible to complications due to freezing conditions. Another disadvantage is that a forced draft design typically requires more motor horsepower than an equivalent induced draft design. The benefit of the forced draft design is its ability to work with high static pressure. Such setups can be installed in more-confined spaces and even in some indoor situations. This fan/fill geometry is also known as blow-through.
• Fan assisted natural draught — A hybrid type that appears like a natural draft setup, though airflow is assisted by a fan.
Hyperboloid (sometimes incorrectly known as hyperbolic) cooling towers have become the design standard for all natural-draft cooling towers because of their structural strength and minimum usage of material. The hyperboloid shape also aids in accelerating the upward convective air flow, improving cooling efficiency. These designs are popularly associated with nuclear power plants. However, this association is misleading, as the same kind of cooling towers are often used at large coal-fired power plants as well. Conversely, not all nuclear power plants have cooling towers, and some instead cool their heat exchangers with lake, river or ocean water.
https://en.wikipedia.org/wiki/Cooling_tower