Infrared Temperature Measurement | Combustion & Environmental Monitoring

Hot Rolling Mill

LAND have supplied the Steel industry throughout the world with temperature measuring equipment for over 60 years. LAND manufacture a complete range of measurement equipment designed specifically for hot metal rolling applications. All are designed to the highest standards of quality and reliability to ensure accurate measurements in the harsh operating conditions of the hot mill. The schematic diagrams illustrate typical features of a hot rolling mills. The areas highlighted show measurement reference points, where LAND's infrared thermometry know-how can really benefit you. If your specific area of concern is not covered here, our engineers will be pleased to discuss your requirements with you.

Stage 1

Stage 1

Stage 2

Stage 2

Stage 3

Stage 3

1. Continuous Caster - Strand Temperature Measurement

Hot_rolling_mill1_0

A very special thermometer is needed here to survive the hostile environment of the spray chamber without constant maintenance. Measurements using the Land Spray Chamber System allow cooling rates in the chamber to be optimised, directly influencing both product quality and process efficiency.

  • Permits process/quality optimization
  • Avoids break-outs

2. Continuous Caster - Withdrawal/Straightening and Exit

Continous_caster

Measurement at the withdrawal/straightening section or exit monitors process uniformity over several strands. Measurements made here can provide vital information on final stage cooling in the spray chamber to ensure uniformity.

Installing an on-line thermometer systems or Landscan linescanners here would:

  • Provide information on cooling in the Spray Chamber
  • Check temperature profile of the hot strand    

3. Soaking Pit - Load Temperature

Soaking_pit

The heating of the soaking pit is controlled using temperature measurements made at the end wall. Knowledge of the pit temperature and necessary soaking times can ensure that ingots leave the soaking pit at the correct temperature

A Cyclops 100 portable thermometer can be used to periodically check both pit and ingot temperatures.

4. Slabbing/Blooming Mill - Billet Temperature Measurement

Slabbing_blooming

Temperature measurement at the exit of the mill is important. If the billet is too cold it needs to be put through the reheat furnace before entering the rolling section, otherwise a product with poor surface condition and unacceptable metallurgical properties could result. Continuous monitoring with a short wavelength thermometer will:

  • Provide ingot to billet temperature loss information
  • Give early warning of possible roll damage

5. Reheat Furnace Charge

Reheat_furnace_charge%20

Temperature measurement of the furnace charge allows adjustment of the furnace firing conditions in the pre-heat zone. Utilising a longer wavelength thermometer will help maximise reheating efficiency by providing an accurate temperature measurement when either hot and cold charging.

6. Reheat Furnace - Load Temperature Measurement

Reheat_furnace_load

Two sensors are used to determine true Reheat Furnace Load temperatures. A radiation thermometer, operating at 3.9µm measures apparent load temperature and a furnace thermocouple or second 3.9µm thermometer is used to measure furnace temperature. These two signals are fed into a Signal processing unit which computes true load temperature.

The Furnace Thermometer System (FTS):

  • Gives true stock temperatures, permitting optimised heating trajectories
  • Provides potential for substantial energy savings
  • Can be installed with the minimum process disruption

7. Reheat Furnace Exit

Reheat_furnace_exit

The exit of the furnace represents the final opportunity to check the stock temperature before entering the mill.

Positioning a Landscan linescanner at the exit will determine temperature distribution i.e. poor uniformity will result in the need for burner adjustment. Landscan improves quality, reduces wastage of product, fuel and time.

A short wavelength thermometer with a Landmark Graphic signal processor using peak picking will give an accurate output avoiding errors due to surface scale. Used in conjunction with the charge and load measurements, it saves both time and fuel.

8. Rolling Mill - Measurement at the Scalebreaker

Rolling_mil_measurement

his provides the first opportunity to measure the temperature of the scale-free metal. Once the scale has been removed, thermometers measure the true surface temperature to ensure it is within rolling limits and to set mill parameters.

Utilising a short wavelength thermometer with a peak picker signal processing option allows the true metal temperature to be passed to mill control equipment.

Using a Landscan linescanner at this point will provide a two dimensional thermal map of the product.

9. Rolling Mill - Measurement at the Roughing Stands

Rolling_mill_measurement_roughing

Measurements should be taken here at regular intervals to assist the operator in making the correct roll settings. This is essential if there are any stoppages so that roll parameters can be adjusted.

  • Using a Landscan linescanner at this point will provide a two dimensional thermal map of the product

Installation of a short wavelength thermometer:

  • Gives an operator information or a mill computer data on which to set roll parameters
  • Can in addition be used as a hot metal detector

10. Rolling Mill - Coiler Temperature - Hot Coil Box

Rolling_mill_coiler

Measurement of the strip, using a short wavelength thermometer on a Landscan linescanner, as it is uncoiled ensures that consistent rolling and finishing temperatures are maintained.

11. Rolling Mill - Finishing Stands Temperature Measurement

Rolling_mill_finishing

It is essential to know the temperature of the finished product to ensure that the correct metallurgical properties have been obtained. Installation of an on-line system or Landscan provides vital information to be transferred to the cooling sections.

12. Rolling Mill - Measurement at the Cooling Section

Rolling_mill_measurement_cooling

The thermal sensitivity of some metals means that monitoring must take place to avoid damage or stresses occurring. It is therefore equally important to maintain high accuracy temperature measurements at the cooling section to benefit the overall quality of the finished product, and to realise the correct properties. Installing a Landscan linescanner at the cooling exit ensures maintenance of product quality throughout the cooling cycle An Understrip Thermometer System USTS can be used to provide a centreline measurement of the underside of the strip on the runout table

13. Understrip Measurement

Understrip_measurement%20

Where there is a requirement for direct rolling of high performance 'dual phase' steels for crash energy-absorbing automotive components, use of an Under Strip Thermometer Systems (USTS) utilising a M3 non contact radiation thermometer thermometer provides a high degree of confidence that the required structure is consistently achieved throughout each coil.

14. Wire/Rod Mill - Measurement at the Water Box

Wire-rod_mill_water

Cooling here needs to be rapid but controlled to ensure metallurgical properties are retained. Insufficient cooling control would result in out of specification material, i.e. scrap or downgrade.

Installation of a Linescanning ratio or target-orbiting (T.O.) thermometer:

  • Allows continuous measurement
  • Provides control to the water spray coolers to retain metallurgical properties
  • Permits a range of rod/bar diameters to be monitored

15. Rolling Mill - Temperature Measurement at the Down Coiler

Rolling_mill_down_coiler

Measurement prior to the down coiler using either a Landscan linescanner or short wavelength thermometer provides feedback on product temperatures for quality control data.

  • A Landscan linescanner provides analog zone outputs for controlled cooling of the trip.

16. Wire/Rod Mill - Measurement at the Laying head and on the Air Cooling Conveyor

Wire-rod_mill

Temperature measurement using either Landscan linescanner, a ratio thermometer or a target-orbiting (T.O.) thermometer in the air cooling zones is vital to ensure both metallurgical structure and hence mechanical properties are retained in the finished product.

On-line measurement should be made in both the laying and cooling zones for effective control.

In addition Landscan linescanner provides:

  • Complete two-dimensional thermal mapping of the laid products

A portable thermometer can be used to monitor laying head temperatures and cooling conveyor temperatures.