New Results to Support Remote Optical Off-gas Temperature

Measurement for EAF Steelmaking

Vadim GutnikSales Manager

Tenova Goodfellow

Outline

• OTM Introduction• Current Off-gas temperature sensing

technologies• TGI temperature sensor• Laboratory Tests• On site Tests• Results• Value to the Plant• Conclusion

Introduction

“When you can measure what you are speaking about and express it in numbers, you know

something about it.When you cannot measure it, your knowledge is

meager and unsatisfactory”

Lord Kelvin

OTM Introduction

Introduction

• Proprietary non intrusive and passive technology (patent pending)

• Readings are not affected with < 70% of field of view obstructed

• Continuous measurement of gas temperature in dust-bearing hot industrial processes.

• Remote and in-duct applications

OTM features

• Continuous, real-time measurement of gas temperature

• Non-contact sensor may be mounted up to 30m away from target

• Passive sensor has no consumable parts and requires virtually no maintenance

• System measures dust-bearing gases at temperatures between 600°C

to 2,000°C

• Sensor measurement output and alarms are available via 4-20 mA and/or Ethernet

• Sensor cabinet is NEMA 4 rated, climate controlled, and suitable for indoor/ outdoor installation

Current OG temperature sensing technology

• Measures intensity of CO2 emission at 4.2 um– Calculates Temperature from the intensity

TcexpcT,I 2

51

Single Wavelength Pyrometers

Current OG temperature sensing technology

• Issues:– Any obstruction of the view (for example dirt on lens) reduces the

intensity measured by the camera and consequently the temperature– An emissivity is assumed for species of interest (for example CO2)– Presence of the required species to a certain concentration is

mandatory

Current OG temperature sensing technology

Thermocouples

• Full contact sensor susceptible to aging• Needs protection when mounting in corrosive, dusty , high temperature

conditions• The protection shroud introduces additional lag to the readings.• Since thermocouples are made up of two dissimilar metals, they are

vulnerable to corrosion, which can sometimes be difficult to detect. Any type of light corrosion can result in a misreading by the thermocouple; therefore, proper care, calibration and maintenance of thermocouples is essential.

• Requires regular maintenance, has a limited operational lifetime

Tenova OTM

TGI temperature sensor

Tenova OTM

• It measures the energy (intensity) emitted by the hot off-gas at several wavelengths

• Wavelengths have been carefully selected after complete spectrum analysis was measured and analyzed in different steelmaking facilities

Tenova OTM

Benefits:

Debris on lens do not influence the intensity ratio Measurement not affected by emissivity variations Remote measurement system Electronics for the sensor are placed at a distance from direct heat Requires virtually no-maintenance Can be used for measurement in all types of extreme conditions

Tenova OTM

Temperature readings of the Tenova off-gas sensor compared to the industrial furnace

Laboratory Tests

Tenova OTM

0 50 100 150 200 250-30

-20

-10

0

10

20

30

Time (Min)

Dev

iatio

n

Deviation in Calculated measurements of temperature.

900 C 1025 C 1175 C750 C

Temperature deviation between sensor and industrial furnace temperatureExcellent repeatability

Site installations

Tests on site

For the tests we installed the sensor at multiple plants at the selected location approximately 20-30m away from furnace with clear line of sight

Sensor head location

Heat data

Subsequent heat data

OTM vs TC

Benefits

Value to the Plant

• Process understanding• Off-gas temperature can be used for energy losses calculation• Process pacing and efficiencies, Process upset• Fume system control (ie. Quencher water flow or primary/secondary FS

Damper control, Scrubber….)• Better environmental control, ensuring decomposition of dioxins, CO=>Co2

conversion• Heat progress

Benefits

Final Conclusions:

The key distinguishing features for TGI’s advanced Optical Temperature sensor include: • This sensor is more sensitive in lower range temperatures and

equally sensitive in higher ranges, high repeatability and accuracy • The sensor is manufactured mill rugged, suitable for industrial usage • It can be used as a remote measuring device and needs no surface

contact. Remote measurement of temperature from a distance of up to 30 m away has been tested.

Advantages

Final Conclusions: • Temperature readings not affected by dust/dirt accumulation on the

optical lens. • Good comparison with the earlier installed temperature sensors.

• Good behavior and dynamics during the heat. • Good reliability of measurements over long periods, high stability

and no temperature drift over time • Does not need daily calibration.

Thank You

Vadim GutnikSales Manger

Tenova Goodfellow IncCanada