Dynamic melt rate control on a Laboratory scale VAR furnace without load cell feedback
- Gregory J.
- Philip K.
- Robert M.
- Rodney L.
Based on a linearized version of an accurate, low order, dynamic melt rate model, a feedback melt rate controller was designed and tested on a small VAR furnace at Los Alamos National Laboratory. Model based control was necessary because the furnace is not equipped with a working load cell transducer. The model was incorporated into a process filter that produces estimates of electrode thermal boundary layer, electrode gap, electrode position and electrode mass. Estimated values for the thermal boundary layer and electrode gap were used for feedback. The input commands were melting current and electrode drive speed. A test melt was performed wherein a 0.127 m diameter 304SS electrode was melted into 0.165 m diameter ingot at a nominal melt rate of 27 g/s. Toward the end of the test, a melt rate step up to 32 g/s was commanded. The controller initiated a nonlinear current ramp to produce the commanded step. Electrode position data were analyzed and the results used to determine that the actual melt rate profile followed the commanded profile relatively well.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 975722
- Report Number(s):
- LA-UR-01-4909; TRN: US201018%%810
- Resource Relation:
- Conference: "Proceedings of American Vacuum Society International Symposium on Liquid Metal Processing and Castings"
- Country of Publication:
- United States
- Language:
- English
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