blast orifice

Blast Blast (bl[.a]st), n. [AS. bl[=ae]st a puff of wind, a blowing; akin to Icel. bl[=a]str, OHG. bl[=a]st, and fr. a verb akin to Icel. bl[=a]sa to blow, OHG. bl[^a]san, Goth. bl[=e]san (in comp.); all prob. from the same root as E. blow. See {Blow} to eject air.] 1. A violent gust of wind. [1913 Webster]

And see where surly Winter passes off, Far to the north, and calls his ruffian blasts; His blasts obey, and quit the howling hill. --Thomson. [1913 Webster]

2. A forcible stream of air from an orifice, as from a bellows, the mouth, etc. Hence: The continuous blowing to which one charge of ore or metal is subjected in a furnace; as, to melt so many tons of iron at a blast. [1913 Webster]

Note: The terms hot blast and cold blast are employed to designate whether the current is heated or not heated before entering the furnace. A blast furnace is said to be in blast while it is in operation, and out of blast when not in use. [1913 Webster]

3. The exhaust steam from and engine, driving a column of air out of a boiler chimney, and thus creating an intense draught through the fire; also, any draught produced by the blast. [1913 Webster]

4. The sound made by blowing a wind instrument; strictly, the sound produces at one breath. [1913 Webster]

One blast upon his bugle horn Were worth a thousand men. --Sir W. Scott. [1913 Webster]

The blast of triumph o'er thy grave. --Bryant. [1913 Webster]

5. A sudden, pernicious effect, as if by a noxious wind, especially on animals and plants; a blight. [1913 Webster]

By the blast of God they perish. --Job iv. 9. [1913 Webster]

Virtue preserved from fell destruction's blast. --Shak. [1913 Webster]

6. The act of rending, or attempting to rend, heavy masses of rock, earth, etc., by the explosion of gunpowder, dynamite, etc.; also, the charge used for this purpose. ``Large blasts are often used.'' --Tomlinson. [1913 Webster]

7. A flatulent disease of sheep. [1913 Webster]

{Blast furnace}, a furnace, usually a shaft furnace for smelting ores, into which air is forced by pressure.

{Blast hole}, a hole in the bottom of a pump stock through which water enters.

{Blast nozzle}, a fixed or variable orifice in the delivery end of a blast pipe; -- called also {blast orifice}.

{In full blast}, in complete operation; in a state of great activity. See {Blast}, n., 2. [Colloq.] [1913 Webster]