Definition of "overfire"

In the interest of smoke abatement, overfire jets are now installed on thousands of commercial and industrial coal-fired furnaces. [...] The overfire jet is a device for providing turbulence and/or overfire air above the fuel bed of hand-fired and stoker-fired furnaces.

1952 December, William S. Major, “The Theory and Practice in the Use of Overfire Jets”, in The Michigan Technic, volume LXXI, number 3, page 13

Volatile matter in the vapor form and carbon monoxide just above the bed must be fully mixed with overfire air to complete the combustion process. At low firing rates it is important to minimize the amount of overfire air to prevent cooling of the volatile matter resulting in incomplete combustion and soot formation.

1989 October, Central Boiler Plants (Technical Manual; TM 5-650), [Washington, D.C.?]: Headquarters, Department of the Army, page 1-13

The primary flame zone can be operated fuel rich to reduce oxygen concentration, then additional air can be added downstream. This overfire air provides oxygen to complete combustion of unburned fuel and oxidizes carbon monoxide to carbon dioxide, creating a second combustion zone. Because there is so little fuel in this overfire zone, the peak flame temperature is low.

2001, Karl B. Schnelle, Jr., Charles A. Brown, Air Pollution Control Technology Handbook, Boca Raton, Fla.: CRC Press, page 245

Over-fire boilers are the simplest and cheapest domestic boilers for burning wood logs. [...] In over-fire boilers, combustion takes place in the whole fuel batch more or less at the same time, as in wood-stoves. The boiler is normally equipped with a primary air inlet under the grate and a secondary air inlet over the fuel batch, into the gas combustion zone.

2008, Sjaak Van Loo, Jaap Koppejan, editors, The Handbook of Biomass Combustion and Co-firing, London, Sterling, Va.: Earthscan, page 118

I found that the Chapelon steamed almost too freely, because on a strange locomotive and road one usually tends to overfire a little through a natural lack of confidence.

1961 February, ""Balmore"", “Driving and firing modern French steam locomotives - Part One”, in Trains Illustrated, page 110

Overfiring the appliance may cause a house fire. If a unit or chimney connector glows, you are overfiring.

1985, Code of Federal Regulations: Commercial Practices […], Washington, D.C.: United States Government Printing Office for the Office of the Federal Register, National Archives and Records Service and General Services Administration, page 322

We have so far concentrated on creosote fires as a source of elevated flue gas temperatures. But overfiring the stove or fireplace – building a large, hot fire – can also produce very high temperatures.

1987 September, Citizens’ Committee for Fire Protection, International Society of Fire Service Instructors, Alternative Heater Fires: A Critical Review of Safety Issues, [Emmitsburg, Md.]: United States Fire Administration, Federal Emergency Management Agency, page 41

BUBBLES IN GLAZE may be caused by too heavy an application, or by severe underfiring or overfiring. [...] LOSS OF COLOR IN CHINA PAINTING is a result of overfiring or mixing too much medium with the paint. Be careful not to overfire china colors, and if a light shade of a dark color is needed, apply the color very lightly rather than thinning too much.

, Dallas, Tex.: Paragon Industries, page 19

At this point overfiring begins, as is shown particularly by the volume curve, which indicates decided bloating, so that at 1450°C the clay has about the same volume it had at 1050°C before vitrification took place. At 1450°C it is, therefore, decidedly overfired. However, its excellent burning behavior is apparent from the long temperature range.

1919, United States. Bureau of Standards, Technologic Papers of the Bureau of Standards, Washington, D.C.: United States Government Printing Office, page 15

The principal criteria of the value of the clay as determined by burning are the overfiring temperature and the softening point.

1922, H[einrich] Ries, W[illiam] S[hirley] Bayley [et al.], High-grade Clays of the Eastern United States: With Notes on Some Western Clays (U.S. Geological Survey Bulletin; 708), Washington, D.C.: Government Printing Office, page 12

Geoffery Schultz, a student of [Ronald] Melzack, has recently conducted a study showing that visual hallucinations need not be caused by psychopathology but may result from the disruption of sensory input among patients suffering eye damage. The neuromatrix, in Melzack's theory, overfires its output messages in the absence of stimulation from external sources (or temping feedback), and creates images – often fantastic or exaggerated – that may be experienced as real.

2003, Ariel Glucklich, Sacred Pain: Hurting the Body for the Sake of the Soul, Oxford: Oxford University Press, page 57