Active temperature feedback control of continuous casting

Abstract

The invention includes a system, method and machine readable program for dynamically controlling the casting of a material. Generally, the systems and methods described herein include an active control feedback system or aspects thereof including a temperature sensing device that is well-suited for the harsh environment of the interior of a caster such as a caster for casting metal. Temperature measurement can be accomplished either directly or indirectly. The system is configured to compare the measured temperature with an ideal casting temperature. The temperature sensing device is operably coupled to a cooling device that modulates a flow of coolant to dynamically cool the material being cast. In accordance with one embodiment of the invention, the cooling device includes a plurality of nozzles for delivering one or more cooling fluids to the material being cast.

1 . A caster for continuously casting metal including:
 a) a mold adapted and configured to mold molten metal into a metal strand;   b) a cooling system disposed downstream of the mold adapted and configured to controllably cool and substantially solidify the strand before exiting the caster; and   c) a temperature measuring device adapted and configured to detect the surface temperature of the strand, the temperature sensor including:
 i) a sensor adapted and configured to detect the temperature of the strand; and 
 ii) a gas purge line operably coupled to the sensor, the gas purge line being adapted and configured to deliver a gas purge to deflect debris from a region of the strand being monitored by the temperature sensor. 
   
   
   
       2 . The caster of  claim 1 , wherein the gas purge prevents coolant from affecting accuracy of temperature measurement. 
   
   
       3 . The caster of  claim 1 , wherein the sensor directly contacts the strand to measure the strand temperature. 
   
   
       4 . The caster of  claim 3 , wherein the sensor includes a thermocouple. 
   
   
       5 . The caster of  claim 1 , wherein the sensor includes a photon sensor that detects photons emitted from the strand to measure the strand temperature. 
   
   
       6 . The caster of  claim 5 , further comprising an elongate tubular member having a first end disposed proximate the strand and a second end disposed proximate the sensor, the tubular member being adapted and configured to permit passage of photons emitted by the strand from the first end of the tubular member to the sensor. 
   
   
       7 . The caster of  claim 6 , wherein the gas purge line directs the gas purge through the tubular member. 
   
   
       8 . The caster of  claim 7 , wherein the purge line is adapted and configured to purge debris away from a radiation path defined between the slab and the photon sensor. 
   
   
       9 . The caster of  claim 8 , wherein the first end of the tubular member is angled to facilitate purging of debris away from the radiation path. 
   
   
       10 . The caster of  claim 5 , wherein the photon sensor includes a pyrometer. 
   
   
       11 . The caster of  claim 10 , wherein the pyrometer is sensitive to a wavelength in at least one of (i) the ultraviolet range of the electromagnetic spectrum, (ii) the visible range of the electromagnetic spectrum and (iii) the near infrared range of the electromagnetic spectrum. 
   
   
       12 . The caster of  claim 11 , wherein the pyrometer is sensitive to wavelengths having a length less than about 0.5 microns. 
   
   
       13 . The caster of  claim 10 , wherein the pyrometer is a two-color pyrometer. 
   
   
       14 . The caster of  claim 1 , further comprising:
 a) a control system operably coupled to the cooling system and the temperature sensor, the control system being adapted and configured to adjust the flow of coolant to the strand in response to a change in strand temperature detected by the temperature sensor.   
   
   
       15 . The caster of  claim 14 , wherein the coolant includes fluid selected from the group consisting of water, air and combinations thereof. 
   
   
       16 . The caster of  claim 14 , wherein the control system is adapted and configured to individually control at least one of (i) an individual cooling nozzle and (ii) a bank of cooling nozzles. 
   
   
       17 . The caster of  claim 1 , wherein the temperature sensor detects the surface temperature of the strand at a location downstream of at least one cooling nozzle. 
   
   
       18 . The caster of  claim 14 , wherein the control system is adapted to perform at least one of: (i) maintaining a substantially controlled surface temperature across the surface of the strand while it solidifies, (ii) controlling the speed of the caster, (iii) controlling the surface temperature of the stream of material by adjusting the speed of the caster or (iv) defaulting from active feedback control to a default cooling setting.