Here are some websites about smoke extraction fans. 押出しwould be about "expelling" but I think the word "extraction" takes care of the concept of "expelling." There are also different models of smoke extraction fans on one of the websites.

http://ejje.weblio.jp/content/排煙
はいえん２ 排煙
排煙装置
a smoke extraction apparatus.

http://www.flextraction.co.uk/products/extraction-fans/smoke...
Sodeca Smoke Extraction Fans
flextraction provide a wide-range of Sodeca Smoke Extraction Fans, of which the main types are displayed below. Please consult the available PDF brochure or call us as we will be able to assist in choosing a suitable fan for your specific requirements.

http://www.freepatentsonline.com/6776708.html
This invention relates to a ventilator wherein an electronic circuit is actuated when a detecting element detects the existence of any smoke or gas while a fan is in a manual selected slow rotating node of operation or in a stand by halting position, and then the fan is automatically put into full rotation in order to expel smoke or such gas as carbon monoxide, and also for a specified period after completion of this expelling operation the fan is kept rotating during the above operation through the function of a delay-off circuit, with a shutter of a ventilating window being kept open by means of a switch network.



The invention relates to protection against fumes resulting from fires in buildings and being vented to the outdoors. A system for protecting one portion of a building against fumes from a fire in another portion having an opening connecting it to the first named portion, said system comprising; a collection duct in said other portion adjacent said opening; an exhaust fan having its inlet connected to said duct and its outlet discharging outdoors; operating means for said fan; an air intake on said one portion side of said opening; and means for causing operation of said fan operating means when such fire occurs to draw air through said opening from said air intake into said other portion to create a draft through said opening to oppose the fumes and with said fumes entrained therewith into said duct and to discharge said air and fumes outdoors.
http://www.theconstructioncentre.co.uk/products/ventilation/...
Independent British extractor fan manufacturer, products ranging from quiet energy-savingextractor fans and controls for kitchens and bathrooms to fume...





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Note added at 1 hr (2011-02-03 00:01:36 GMT)
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Here is a website for the company “Wolf” which makes large smoke extractor fans for commercial use:
http://www.archiexpo.com/prod/wolf/commercial-smoke-extracto...
Commercial smoke extractor fans


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Note added at 2 hrs (2011-02-03 01:21:46 GMT)
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The word “impeller” is seen to be paired with smoke exhaust fans on a couple of sites. "Impel" literally means “cause to move forward with force.” And, impeller is the device that sends out the smoke...The below website has an "aluminum" impeller...

So, if desired, and depending on the rest of the translation "impeller emergency smoke extraction fans" can be another alternative.

http://www.kellysearch.com/ie-product-36718.html
Aluminum Impeller Emergency Smoke Extraction Fans Suppliers