Application Case of a Domestically Produced Zirconia Oxygen Analyzer in the Vallourec Annular Natural Gas Heating Furnace

Abstract

The rotary heating furnace is a core thermal‑process unit in the production of specialty steel tubes. Powered by natural gas, the oxygen content within the furnace is a critical parameter for combustion control, energy conservation, product quality management, and safe production. The rotary heating furnace at Vallourec (China) Co., Ltd. was originally equipped with an imported German‑brand oxygen analyzer, which has long suffered from high maintenance costs and lengthy lead times for spare parts. Anhui Tianfen Instrument Co., Ltd. has since… 2017  Since [year], we have engaged in in-depth technical cooperation with Vallourec, aiming to… TF-WSPZOBXL8200 Zirconia oxygen analyzer It has gradually replaced previously imported-brand equipment; after years of continuous field‑operational validation, the equipment has demonstrated high measurement accuracy and stable performance, successfully achieving domestic substitution for high‑end metallurgical furnace and kiln equipment previously sourced from abroad. This provides a mature, domestically developed solution for online monitoring of oxygen content in domestic metallurgical annular heating furnaces.

Keywords : Zirconia oxygen analyzer; annular heating furnace; natural gas combustion; online oxygen monitoring; metallurgical furnaces and kilns; domestic substitution; oxygen analysis system

1  Project Background

Valuric ( Vallourec ) is a globally renowned foreign-invested manufacturer of high-end seamless steel pipes. Its production lines are equipped with multiple large-scale annular reheating furnaces that use natural gas as fuel to heat steel pipe billets. Annular reheating furnaces are continuous high-temperature industrial furnaces; their internal combustion conditions are complex, with significant temperature fluctuations, and the flue gases contain particulates and water vapor, posing challenges to oxygen analyzers. Measurement accuracy, long-term stability, and robustness under harsh operating conditions All have put forward stringent requirements.

During the project’s preliminary phase, the annular reheating furnace was equipped with an oxygen analyzer of German origin; however, prolonged operation gradually revealed a series of issues:

1. Imported equipment is costly to procure, and the lead times for sensors and spare parts are lengthy; if a component fails, it can disrupt furnace combustion control, posing a risk of shutdown.
2. On-site operations and maintenance pose a high barrier to entry, with slow response times from the original equipment manufacturer’s after-sales support, and on-site maintenance relies on overseas technical assistance.
3. The overall system lacks flexibility in its configuration, making it difficult to accommodate fine-tuning requirements under site-specific operating conditions.

To reduce production and operation costs and ensure the continuous, stable operation of the heating furnace, Vallourec has initiated a project to select and implement domestically produced replacements for its oxygen analyzers. Anhui Tianfen Instrumentation, as a specialized… Zirconia oxygen analyzer manufacturer ，2017  In the year, project alignment was initiated, followed by multiple rounds of technical exchanges, on-site operational condition assessments, solution design, and prototype testing, resulting in the first set… Zirconia Oxygen Analyzer System Successfully commissioned the annular heating furnace on-site, marking the start of the phased replacement of imported equipment.

2  Operating Condition Analysis and Scheme Design

2.1 Characteristics of the On-Site Operating Conditions

• Furnace type: annular heating furnace; fuel: natural gas.
• Monitoring objective: To continuously monitor flue gas oxygen levels, optimize the air–fuel ratio, achieve energy‑efficient natural gas combustion, control oxidation‑related burnout, and ensure the quality of heat treatment for steel billets.
• Flue gas characteristics: high-temperature flue gas containing trace amounts of particulates and water vapor, with significant operational fluctuations.
• Measurement requirement: online continuous oxygen concentration monitoring, 4-20mA Signal Upload DCS The system features long-term stability and requires no frequent maintenance.

2.2 Talent Meter TF-WSPZOBXL8200 Oxygen Analyzer System Solution

Customized by Anhui Tianfen Instrumentation for the natural gas combustion operating conditions of the Valuric annular heating furnace. TF-WSPZOBXL8200 Zirconia Oxygen Analyzer Complete System , the entire set of equipment is composed of Zirconia probe, instrument control cabinet, pretreatment module, rotameter, valve assembly Integrated within the integrated control cabinet.

1. Core Measurement Unit : Zirconia sensor, directly inserted into the furnace flue for sampling and analysis, offering rapid response and real-time measurement of flue gas oxygen concentration; measurement range 0~25% O ₂ , perfectly meets the combustion monitoring requirements of heating furnaces;
2. Signal output : Standard 4-20mA Analog output, enabling seamless integration with the factory’s existing system. DCS Control system; data is being uploaded to the central control in real time.
3. Human-computer interaction : Color LCD display that simultaneously shows oxygen concentration, temperature, and other parameters; allows on-site data viewing and supports parameter configuration and calibration functions.
4. Gas Path Assembly : Equipped with a rotameter and purge valves to enable ash‑free purging of the probe, thereby reducing flue gas particulate contamination of the probe, extending sensor service life, and minimizing on-site maintenance requirements.
5. Cabinet Protection : Industrial-grade outdoor /  Workshop control cabinet, designed to withstand the harsh industrial conditions of metallurgical workshops—high temperatures, dust, and vibration.

The entire system requires no complex pre‑processing, is easy to install, and can be seamlessly integrated into existing equipment mounting locations. After removing the old meter, it can be directly installed, significantly reducing on‑site retrofitting work and ensuring uninterrupted continuous operation of the furnace.

3  On-site application results

Since 2017 The first piece of equipment was commissioned at the beginning of the year—Tianfen Instruments. Zirconia oxygen analyzer It has been operating continuously and reliably at the Valuric annular gas-fired heating furnace site, as confirmed by years of on-site measurements:

1. Accurate and reliable measurement : The oxygen content measurement data are stable, with minimal deviation when compared to laboratory results, accurately reflecting the combustion status of natural gas within the furnace and providing a reliable basis for air‑fuel ratio control.
2. The device boasts strong stability. : Adapts to the complex flue-gas conditions of annular reheating furnaces, exhibits strong resistance to dust and temperature fluctuations, features a low failure rate, and reduces the frequency of instrument shutdowns for maintenance.
3. Operational costs have dropped significantly. Domestic equipment boasts significantly lower procurement costs than imported brands, with readily available spare parts and a domestic technical team that responds swiftly. On-site calibration and troubleshooting are highly efficient, effectively addressing the challenges of slow after-sales service and expensive spare parts associated with imported equipment.
4. Gradual product replacement and implementation Following the successful validation of the first piece of equipment, Vallourec expressed strong approval of Tianfen Instrument’s oxygen‑monitoring system and proceeded to replace the original German‑brand oxygen analyzers at the remaining measurement points along the production line, in phased batches, with products from Anhui Tianfen Instrument. Zirconia oxygen analyzer , achieving the localization and deployment of multiple instruments.

With this online oxygen monitoring system, Vallourec’s annular reheating furnace achieves precise control of the natural gas–air ratio, effectively reducing fuel waste, minimizing oxidation and burn-off losses in billets, enhancing the quality of finished tubular products, and ensuring safe and reliable furnace operation. The continued procurement over many years by foreign‑invested, high‑end metallurgical enterprises is ample evidence of the superior performance of domestically produced solutions. Zirconia oxygen analyzer In high-end industrial furnace applications, it can fully replace imported brands.

4  Project Summary and Industry Value

This case is Domestically produced zirconia oxygen analyzers in large foreign‑invested metallurgical annular natural gas heating furnaces. A successful example of import substitution. Anhui Tianfen Instruments provides customers with end-to-end, one-stop oxygen‑monitoring solutions—covering everything from initial technical coordination and on-site surveys to customized system design, equipment manufacturing, field commissioning, and long-term after-sales service—thereby breaking the monopoly of foreign brands in the high‑end metallurgical furnace and kiln oxygen‑analysis market.

For industrial furnaces such as rotary hearth furnaces, pusher‑type furnaces, roller kilns, and heat‑treatment furnaces, combustion optimization is inseparable from online oxygen‑content monitoring. Anhui Tianfen Instruments, a domestic specialist… Zirconia oxygen analyzer manufacturer With deep expertise in oxygen measurement, our products are widely used across industries such as metallurgy, heat treatment, lithium‑ion battery manufacturing, boiler operations, and petrochemicals. We can tailor complete oxygen analysis systems to suit various furnace types and fuel sources, including natural gas, coal gas, biomass, and more.

Under the overarching trend of domesticating industrial equipment, we continue to refine and improve. Zirconia oxygen analyzer With a focus on high stability, high precision, and exceptional cost-effectiveness, our products offer industrial enterprises an alternative to imported flue‑gas online oxygen monitoring solutions, helping industrial furnaces and kilns improve energy efficiency, reduce equipment procurement costs, and lower operational and maintenance expenses.

Anhui Tianfen Instrument Co., Ltd. specializes in the manufacture of zirconia oxygen analyzers and trace oxygen analyzers, offering one-stop services that include custom-designed gas analysis systems, on-site surveys, system design, and on‑site commissioning. We welcome customers from all industries to consult with our technical experts and arrange site visits.