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Measurement and Monitoring of O2 Concentrations>
Measurement and Monitoring of O2 Concentrations

Measurement and Monitoring of O2 Concentrations

Industry	: Iron and Steel
Product	: Zirconia Oxygen Analyzer

Introduction

Measurement and Monitoring of O2 Concentrations in Steel Mill Reheating Furnaces

Reheating Furnace Process

Reheating Furnace Process

A furnace for heating slabs needs to be operated under low oxygen conditions at high temperatures of 1000°C and above to prevent oxidation of the steel. The measurement of oxygen concentrations in the furnace is essential in this process.
The ZR22/ZR402 Direct In-Situ 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 high-temperature environment. The ZR22G detector with the ZO21P high temperature probe adapter can be used in gas furnaces at temperatures up to 1400°C.

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°C 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-☐-☐☐☐-☐*A
	Auxiliary ejector for high temperature use
		P/N E7046E☐
	Converter:
		ZR402G-☐-☐-E-A
	Flow setting unit:
		ZA8F-☐*B
	Calibration gas unit
		Pressure regulator for gas cylinder:
		P/N G7013XF (inlet W22, outlet Rc1/4) or P/N G7014XF (inlet W22, outlet 1/4NPT)
Measurement System		Case assembly for calibration gas cylinder: P/N 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.