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Catalogue of developments

Catalogue of developments/COMPLEX OF TECHNOLOGIES FOR TEMPERATURE CONTROL/2.Continuous temperature control

2.3 Contactless temperature control of molten metal

2.3.1 Contactless thermometry technologies


  The technologies are purposed for the technical realization of continuous distant temperature measurement, registration and regulation technologies in foundry, metallurgy, ceramic, glass and other industries. For example, it can be used for continuous temperature measurement of liquid metal in a stream or flow during tapping from metallurgical furnaces and aggregates, as well as the slab under mold in a continuous casting machine; metal sheet, strip or wire.

Operation principle

  It is based on the contactless radiation pyrometry of the controlled surface in zones and spectrum ranges with the most stable emissivity (ε) and transmissivity (τ), with the following processing of primary pyrometric information in accordance with the algorithms of multicolour, for example, symmetric-wave thermometry (SWT), eliminating influence of ε and τ.

Main tеchnical characteristics

Range of measuring temperatures, °С 600...2500.
Measurement error, % ≤1,0.


  Measurement errors of known solutions, including the classical one-color (energy) and two-color (spectral ratio) radiation pyrometry, reach 10 percent or more under conditions of metallurgical production. This, at best, limits or completely excludes their practical use. The measurement errors of the CTS with SWT-algorithm are smaller than the classical energy, spectral ratio and the known multicolour thermometry ones in 4,9-13,2; 3,1-3,6 and 2,3 times, respectively.

Теchnical-economical efficiency

  CTS provides non-alternative continuous temperature control and optimal operation of the technological processes temperature regimes.

Patent protection

  Protected by 23 patents of Ukraine.

2.3.2 Contactless thermometry technologies under industrial conditions

Сontactless temperature control scheme.

Main functional elements of the contactless spectral thermometry system.

Functional elements of the contactless spectral thermometry system placement scheme on the pouring furnace.

Tuyere with primary pyrometric transducer on cupola-furnace with a closed syphon spout and a rotary mixer.

Tuyere with primary pyrometric transducer and viewfinder device on cupola-furnace with an open spout and a rotary mixer.

Carry-out digital indicator device to indicate the temperature of liquid cast iron in cupola-furnace.

Tuyere with primary pyrometric transducer on arc furnace.

Carry-out digital indicator device to indicate the temperature of liquid cast iron in arc furnace.

2.3.3 Spectral thermometry technologies: spectral-compensative, symmetric-wave, two-color compensative and based on spectral emissivity distribution nonlinearity

  Symmetric-wave thermometry is based on determined by us and sufficient for practical use correlation between emissivity value of metal alloys in condensed state in average part of operating range of spectrum and emissivity values on symmetrically placed boundary parts of spectrum. The established correlation allows obtaining the common pyrometric equation for a linear SWT, which is solved numerically with respect to the desired temperature of alloy T.

© Leonid F. Zhukov. 2007-2023