Introduction
A furnace for heating slabs needs to be operated under low oxygen conditions at high temperatures of 1000℃ and above to prevent oxidation of the steel. The measurement of oxygen concentrations in the furnace is essential in this process.
The ZR22G/ZR802G Zirconia Oxygen Analyzer requires no sampling system and utilizes a long-life sensor, and is therefore ideally suited for measurement of oxygen concentrations in a hightemperature environment. The ZR22G detector with the ZO21P high temperature probe adapter can be used in gas furnaces at temperatures up to 1400℃.
Expected Benefits
- Maintains high product quality by monitoring oxygen concentrations in steel mill reheating furnaces
- Ensures stable, continuous measurement of oxygen concentrations
- Reduces operating costs
Process Overview
Slabs are loaded on a conveyor and fed to a reheating furnace, which is heated to between 900 and 1400℃ by burners that use fuels such as by-product gas. In order to keep the oxygen concentration between 1 and 2%, it is monitored in the preheat, heat , and soak zones. The slabs are heated uniformly without being oxidized, and then sent to the next processing stage.
Solution Details
Field Data
| Process conditions | |
|---|---|
| Measurement point: | furnace reheat, heat, and soak zones |
| Temperature: | 900°C to 1400°C |
| Pressure: | 30 to 50 kPa |
| Dust: | Trace |
| Fuel: | Gas |
Measurement system
| Detector: | ZR22G-015-S-Q-☐-☐-☐-E-A/CV |
|---|---|
| High temperature probe adapter: | ZO21P-H-☐-☐☐☐-☐*B |
| Auxiliary ejector for high temperature use: | E7046E☐ |
| Converter: | ZR802G-☐-☐-N-N/☐ |
| Flow setting unit: | ZA8F-☐*C |
| Calibration gas unit | |
| Pressure regulator for gas cylinder: | G7013XF (inlet W22, outlet Rc1/4) or G7014XF (inlet W22, outlet 1/4NPT) |
| Case assembly for calibration gas cylinder: | E7044KF |
Note: the calibration gas cylinder must be purchased locally.
Probe Adapter
| Utilities | |
|---|---|
| Power supply: | 85 to 264 V AC, 50/60 Hz |
| Instrument air (reference gas): | pressure, 300 to 700 kPa |
Notes
The material selected for the high temperature probe adapter depends on the temperature of the sample gas. Follow instructions carefully when installing the probe.
| SUS: | Sample gas temperature ≤ 750°C |
|---|---|
| Probe orientation: | vertical or horizontal |
| Inconel: | 750°C < sample gas temperature ≤ 900°C Probe orientation: vertical or horizontal |
| SiC: | 900°C < sample gas temperature ≤ 1400°C Probe orientation: vertical |
Note:
When the probe is installed horizontally, bracings must be provided for mechanical support
Industries
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Iron & Steel
In the iron and steel industry, it is crucial to improve the quality of not only products but also manufacturing and operation technologies, as well as to address environmental and energy-efficiency issues. Yokogawa helps customers to create the ideal plant and evolves with them for mutual growth.
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Zirconia Oxygen/Humidity Analyzer ZR22G, ZR802G
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ZR22G and ZR802G can be measured directly and continuously without a sampling device. It is easy to maintain and reduce operating costs by self-diagnosis of sensor deterioration (without using calibration gas )and replacing the heater assembly on site. -
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