Measurement of charge bank level in a metallurgical furnace

Patent metadata

Field	Value
Publication number	US-9417322-B2
Application number	US-201113093947-A
Country	US
Kind code	B2
Filing date	Apr 26, 2011
Priority date	Apr 26, 2010
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

Various systems and methods for monitoring the level of a feed material layer in a metallurgical furnace are described. At least one non-contact sensor is used to sense a distance between the feed layer and a reference position. A process controller linked to the sensor provides a control signal based upon the sensed distance. The control signal may be used to control various factors in the operation of the metallurgical furnace.

First claim

We claim:

1. A method of monitoring a feed material layer in a metallurgical furnace, the metallurgical furnace being an electric furnace and comprising a plurality of layers of material content, the method comprising:
providing at least one non-contact sensor positioned above the feed material layer contained in the furnace while the furnace is in use, wherein the at least one non-contact sensor comprises at least one transmitter, and wherein the at least one transmitter is configured to emit an electromagnetic signal towards the plurality of layers;
providing a protective housing to protect each non-contact sensor;
thermally shielding each sensor by providing a thermal radiation shield between each non-contact sensor and the feed material layer;
flushing each protective housing with cooling gas;
sensing a sensed distance between an upper surface of the feed material layer and a reference position using the at least one non-contact sensor;
providing a process controller communicably linked to the at least one non-contact sensor to generate a control signal based on the sensed distance; and
outputting the control signal
wherein the non-contact sensor is electromagnetically insulated from electromagnetic interference present in the metallurgical furnace;
wherein the non-contact sensor and characteristics of the electromagnetic signal are selected to penetrate the electromagnetic interference; and
wherein the protective housing comprises a removable cassette containing refractory cloth to provide thermal shielding.

2. The method of claim 1 , wherein the at least one non-contact sensor further comprises providing at least one receiver above the feed material layer; and wherein sensing the sensed distance comprises collecting a reflection of the electromagnetic signal off the upper surface of the feed material layer using the at least one receiver and comparing the electromagnetic signal emitted by the at least one transmitter to the reflection collected by the at least one receiver.

3. The method of claim 1 , further comprising using the process controller to control at least one of a feed material supply rate, an electrode position and an electrode power supply based on the control signal.

4. The method of claim 2 , wherein the electromagnetic signal is compared to the reflection and the control signal is output by the process controller in real-time.

5. The method of claim 2 , further comprising providing a display and generating a display output based on the control signal.

6. The method of claim 2 , wherein providing the at least one non-contact sensor comprises providing a plurality of transmitters above the feed material layer, and sensing the sensed distance comprises providing a corresponding plurality of receivers above the feed material layer, and determining one sensed distance corresponding to each transmitter.

7. The method of claim 6 , wherein providing the process controller to generate a control signal comprises providing the process controller to generate a plurality of control signals, each control signal based on one sensed distance.

8. The method of claim 6 , wherein providing the process controller to generate the control signal comprises providing the process controller to generate a surface topography based on the plurality of sensed distances and a surface control signal based on the surface topography.

9. The method of claim 2 , further comprising positioning the at least one non-contact sensor in a second position to sense a second sensed distance between a second location on the surface and the reference position.

10. The method of claim 1 , further comprising providing the at least one non-contact sensor to sense a second sensed distance between a second layer and the reference position, the second layer being a layer other than the feed material layer from the plurality of layers, and the second sensed distance being sensed based on the reflection of the electromagnetic signal off the surface of the second layer.

11. The method of claim 1 , wherein providing the at least one non-contact sensor comprises providing the at least one non-contact sensor in a fixed position above the feed material layer.

12. The method of claim 1 , wherein the metallurgical furnace comprises a plurality of feed ports, and wherein providing the at least one non-contact sensor comprises providing the at least one non-contact sensor in a position proximate to at least one of the plurality of feed ports.

13. The method of claim 1 , wherein the metallurgical furnace comprises a plurality of electrode ports, and wherein providing the at least one non-contact sensor comprises providing the at least one non-contact sensor in a position proximate to at least one of the plurality of electrode ports.

14. The method of claim 1 , wherein providing the at least one non-contact sensor comprises positioning the at least one non-contact sensor above a corresponding opening in a roof of the metallurgical furnace, the opening providing an unobstructed line of sight to the feed material layer.

15. The method of claim 8 , wherein providing the process controller to generate a surface control signal based on the surface topography comprises providing the process controller to compare the surface topography to a pre-determined surface topography and generate the surface control signal based on the comparison.

16. The method of claim 3 , wherein using the process controller to control at least one of the feed material supply rate, the electrode position and the electrode power supply comprises using the process controller to obtain a feed material level based on the reflection of the electromagnetic signal off the upper surface of the feed material layer, obtain a slag level based on the reflection of the electromagnetic signal off the upper surface of a slag layer, compare the feed material level and the slag level to determine a feed material height, compare the feed material height to a range of pre-determined feed material heights and adjust the at least one of the feed material supply rate, the electrode position and the electrode power supply based on the comparison of the feed material height to the range of pre-determined feed material heights.

17. The method of claim 3 , further comprising:
communicably linking the process controller to a feed actuator,
wherein outputting the control signal comprises generating the control signal to automatically regulate the feed material supply rate based on the control signal.

18. The method of claim 3 , further comprising:
communicably linking the process controller to an electrode actuator,
wherein outputting the control signal comprises generating the control signal to automatically move an electrode from a first position to a second position based on the control signal.

19. The method of claim 3 , further comprising:
communicably linking the process controller to an electrode power supply regulator,
wherein outputting the control signal comprises generating the control signal to automatically regulate the power supplied to an electrode based on the control signal.

20. The method of claim 1 , further comprising:
selecting the non-contact sensor from the group consisting of a laser sensor, an automated sounding sensor, an optical sensor, a Muon particle sensor, an acoustic sensor, a pulsed or frequency modulated electromagnetic sensor, an ultrasound sensor and a yo-yo sensor.

21. The method of claim 1 , wherein the characteristics of the electromagnetic sign

Assignees

• Sadri Afshin
• Shameli Ehsan
• Venditti Roberto
• Kepes Andrei
• Gerritsen Terry
• Southall Sean
• Uyeda Bruce
• Hatch Ltd

Inventors

• Sadri Afshin
• Shameli Ehsan
• Venditti Roberto
• Kepes Andrei
• Gerritsen Terry
• Southall Sean
• Uyeda Bruce

Classifications

• G01B7/023

  for measuring distance between sensor and object (G01B7/082 and G01B7/102 take precedence) · CPC title

• G01S13/88 Primary

  Radar or analogous systems specially adapted for specific applications (electromagnetic prospecting or detecting of objects, e.g. near-field detection, G01V3/00) · CPC title

• G01S7/03

  Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver · CPC title

• B22D2/003

  for the level of the molten metal (B22D11/181 and B22D11/201 take precedence; level indicators in general G01F23/00) · CPC title

• F27D21/0028

  Devices for monitoring the level of the melt · CPC title