Thermox PreMix 2000 Oxygen Analyzer
| Brand | PROCESS INSTRUMENTS |
|---|---|
| Origin | USA |
| Model | PreMix 2000 |
| Measurement Range | O₂: 0.1–100% vol |
| Excess Fuel | 0.1–50% vol |
| Accuracy | ±0.1% O₂ or ±2% of reading |
| Repeatability | ±0.2% of reading |
Overview
The Thermox PreMix 2000 Oxygen Analyzer is a high-stability, in-situ combustion optimization instrument engineered for real-time monitoring and control of air-to-fuel ratios in industrial fired processes. It employs a robust zirconia-based electrochemical sensing principle—operating at elevated temperatures (typically >650 °C)—to quantitatively measure residual oxygen concentration or unburned fuel content in post-combustion flue gas streams. Unlike extractive paramagnetic or laser-based analyzers, the PreMix 2000 integrates direct hot-wet sampling with catalytic combustion conditioning, enabling accurate determination of stoichiometric deviation without external calibration gases. Its design targets continuous operation in harsh thermal environments where precise combustion efficiency directly impacts product quality, energy consumption, and NOₓ emissions—particularly in glass melting furnaces, fiberglass forming ovens, flame surface treatment systems, and controlled-atmosphere metal heat-treating furnaces.
Key Features
- Zirconia oxide sensor with integrated reference air channel and thermally stabilized measurement chamber for long-term baseline stability
- Hot-gas sampling architecture eliminating condensation-related drift and enabling true in-stack measurement without sample conditioning systems
- Dual-mode output: simultaneous analog (4–20 mA) and digital (RS-485 Modbus RTU) signals for integration into DCS, PLC, or SCADA platforms
- Self-diagnostic firmware with sensor health monitoring, temperature validation, and fault logging compliant with ISA-84 SIS Level 1 requirements
- Stainless steel 316L probe housing rated for continuous exposure up to 1200 °C ambient furnace wall temperatures
- No consumables or periodic zero/span gas required under normal operating conditions
Sample Compatibility & Compliance
The PreMix 2000 is validated for use with natural gas, propane, hydrogen-enriched syngas, and other hydrocarbon-based fuel mixtures combusted in oxidizing atmospheres. It tolerates particulate loading typical of glass furnace exhaust (<5 mg/m³) and resists sulfur poisoning up to 50 ppm H₂S when operated above 700 °C. The analyzer conforms to CE marking requirements (2014/30/EU EMC Directive and 2014/34/EU ATEX Category 2G for Zone 1 installations). All electronics meet IEC 61000-4 immunity standards, and mechanical construction complies with ASME B31.1 power piping guidelines for probe mounting integrity. Documentation supports audit readiness for ISO 9001:2015 process control validation and FDA 21 CFR Part 11 data integrity requirements when paired with compliant data acquisition software.
Software & Data Management
Configuration and diagnostics are performed via the Thermox Configuration Utility—a Windows-based application supporting password-protected parameter editing, firmware updates, and real-time sensor diagnostics (including impedance spectroscopy trending). Logged data (O₂ %, excess fuel %, sensor temperature, status flags) is timestamped with millisecond resolution and exportable in CSV or XML format. When connected to enterprise historian systems (e.g., OSIsoft PI, Emerson DeltaV Datalogger), the device supports automatic tag registration and alarm state mapping per ISA-18.2 standards. Audit trails record all configuration changes, including user ID, timestamp, and pre-/post-change values—satisfying GLP/GMP traceability requirements for regulated manufacturing environments.
Applications
- Glass tank furnace combustion control: maintaining optimal air/fuel ratio across regenerative checkerwork cycles to minimize refractory wear and improve melt homogeneity
- Fiberglass bushing furnace optimization: stabilizing flame geometry and temperature profile during fiber drawing to reduce breakage and diameter variation
- Flame treatment of polymer films: ensuring consistent surface oxidation for improved ink adhesion without substrate degradation
- Atmosphere-controlled brazing furnaces: verifying reducing gas composition (e.g., N₂/H₂ mixtures) by indirect O₂ inference in post-combustion zones
- On-site gas generator monitoring: validating purity of on-demand nitrogen or synthetic air streams used in inerting applications
FAQ
How does the PreMix 2000 differentiate between residual O₂ and unburned fuel in the same measurement?
It leverages dual-point zirconia cell operation: one segment measures total oxygen partial pressure, while a second catalytically promoted segment oxidizes residual combustibles, producing a differential voltage signal proportional to excess fuel concentration.
Can the analyzer be installed on existing furnace ports without major retrofitting?
Yes—the standard probe assembly fits standard 1.5-inch NPT or DN40 flanged ports; optional water-cooled jackets and purge collars are available for ultra-high-temperature or high-dust applications.
What maintenance intervals are recommended for sustained accuracy?
Sensor replacement is typically required every 18–24 months in continuous service; quarterly verification using certified span gas (if process permits) is advised for critical control loops.
Is remote diagnostics supported over industrial Ethernet?
While native Ethernet is not included, third-party protocol gateways (e.g., HMS Anybus) enable seamless integration into PROFINET, EtherNet/IP, or OPC UA networks.
Does the system support SIL 2-rated safety functions?
The base analyzer is SIL 1 capable; when combined with certified logic solvers and redundant sensor configurations per IEC 61511, it can contribute to SIL 2 burner management systems.
