Engineering:Wire gauze
Wire gauze or wire mesh is a gauze woven of metal wire, or very fine, gauze-like wire netting. Wire gauze is placed on the support ring that is attached to the retort stand between a burner and glassware, or is placed on a tripod to support beakers, flasks, or other glassware to protect it during heating.[1][2] Glassware should not be heated directly by the flame of a Bunsen or other gas burner; wire gauze diffuses the heat and protects the glassware. Glassware has to be flat-bottomed if rested on the wire gauze.[3]
Wire gauze was also used in safety lamps containing a flame in coal mines and environments where flammable gases may build up; the gauze prevents the flame from igniting gas outside the lamp, causing an explosion.
Some wire gauze is made with a ceramic centre.[4] Plain wire gauze can transmit heat efficiently, but gauze with a ceramic center disperses the heat more evenly.[4] The ceramic at the centre of the wire gauze is enmeshed at high pressure to prevent it from peeling.[5]
Traditionally the ceramic centre has contained asbestos. Although most suppliers in the EU now certify their ceramic-centred gauzes to be asbestos-free, imports from other countries may still contain it.[6]
Wire gauze may be woven from metals including iron,[5] steel,[7] copper,[8] and nichrome.[9] Nichrome alloy provides long life expectancy and tear resistance.[5][9] The edges of the wire gauze are turned inward to help prevent fraying,[5] improve handling, and eliminate sharp protruding wire ends.
Ceramic-centered wire gauze is typically made in 4 inches (100 mm), 5 inches (130 mm), and 6 inches (150 mm) squares[3] to accommodate different sizes of glassware.
Additional images
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6-inch (150 mm) and 5-inch (125 mm) wire gauze squares -
Beaker supported on wire gauze -
Beaker supported on wire gauze on tripod
See also
References
- ↑ Mr Eisley (7 July 2004). "Laboratory Equipment > Supports". http://www.mreisley.com/tutorials/equipment/supports.html.
- ↑ "Chemistry Lab Equipment". Crescent High School. http://crescentok.com/staff/jaskew/isr/tigerchem/equip/equip.htm.
- ↑ 3.0 3.1 "CR Scientific: Catalog: Chemistry: Laboratory Wire Gauze with Ceramic Center". http://www.crscientific.com/wiregauze.html.
- ↑ 4.0 4.1 "What Is Wire Gauze? (with pictures)". http://www.wisegeek.com/what-is-wire-gauze.htm.
- ↑ 5.0 5.1 5.2 5.3 "Iron Wire Gauze with Ceramic | VWR". https://us.vwr.com/store/catalog/product.jsp?product_id=8878194.
- ↑ "Asbestos-containing gauzes in schools". HSE. https://www.hse.gov.uk/asbestos/wire-gauzes-faqs.htm#:~:text=Analysis%20of%20the%20gauze%20material,of%20these%20very%20fine%20fibres..
- ↑ "Wire Gauze Squares, Steel, 4" x 4"". https://www.flinnsci.com/wire-gauze-squares-steel-4-x-4/ap8350/.
- ↑ "Wire Gauze Mat - Bunsen Burner, circa 1910". https://collections.museumsvictoria.com.au/items/259064.
- ↑ 9.0 9.1 "Wire Gauze Squares, Nichrome, 4" x 4"". http://www.flinnsci.com/store/Scripts/prodView.asp?idproduct=14389.
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