Sampling toxic gases like hydrogen sulfide (H2S) or sulfur dioxide (SO2) for analysis poses significant challenges, primarily due to the high toxicity of these gases, the presence of high water or sulfur dew points, and the disposal of the hazardous analyzed sample. These challenges often lead to the abandonment of analyzers due to safety concerns rather than mechanical failures.
An ideal solution to address these issues is a probe designed to require only a single process connection for both sample extraction and safe return. Integrated with a built-in aspirator, our HAG and ASR probes use instrument air, nitrogen, or steam as the driving force, managed by the analyzer.
When the analyzer operates in measuring/sampling mode, without faults or alarms, it draws the sample through heated lines from the process pipe to the analyzer. After analysis in the sample cell, the sample is returned safely back through the same connection. This streamlined process ensures both efficient sampling and safety, making the system a comprehensive safety solution.
The probes are designed to effectively isolate and purge the entire analyzer system before maintenance, eliminating the risk of H2S exposure.
Heated Acid Gas (HAG) Probe
The heated acid gas (HAG) sampling probe is an advanced, electrically heated probe designed for seamless integration with AMETEK's hydrogen sulfide analyzers, such as the IPS-4 feed gas analyzer. It features integrated shut-off valves and a serviceable membrane filter to protect downstream analyzers from liquids and ensures sample integrity with temperature control to prevent condensation. With a single process connection for sample extraction and return, the HAG probe simplifies installation and maintenance, providing reliable sample circulation through its heated aspirator. Compliant with NACE MR0175-2002, it is ideal for sour gas and sulfur recovery unit (SRU) tail gas treatment unit applications, combining efficiency and safety in a compact design.
Figure 1. Heated acid gas sample probe with optional double block valve (special applications)
Advance Sulfur Reduction (ASR) Probe
The advance sulfur reduction (ASR) probe is a pivotal component for sulfur gas analysis, providing primary sample conditioning directly at the tail gas pipe. It effectively removes sulfur vapor, fog, and mist using a centrifugal chamber and demisting mesh pad. The probe features a temperature-controlled body with integrated components for sulfur reduction, including a condenser, coalescer, and aspirator. Its unique design ensures safe and easy maintenance, with reduced installation costs and flexibility in analyzer placement. The ASR900 is essential for accurate sulfur recovery unit analysis and air demand monitoring, maintaining efficiency and safety in sulfur handling processes.
Figure 2. Basic ASR900 sample probe flow diagram, with optional double block valve (special applications).
Comparison
The probes are designed to handle challenging gas sampling scenarios, but they cater to different applications and have distinct features.
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HAG Probe
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ASR Probe
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Application
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- Specifically designed for handling and analyzing acid gases such as hydrogen sulfide (H₂S) in harsh, toxic environments.
- Primarily used in H₂S, CO₂ and hydrocarbon analysis where safety and reliability in handling corrosive gases are paramount.
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- Designed to suppress sulfur vapor and manage sulfur compounds in gas streams, especially in the context of tail gas analysis in sulfur recovery units (SRUs).
- Focuses on reducing sulfur vapor dew points and removing entrained sulfur fog, mist, and liquids at the sampling point.
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Key Features
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- Equipped with integrated shut-off valves for safety, allowing maintenance without removing the probe from the process.
- Contains a serviceable membrane filter to prevent liquid ingress and protect downstream analyzers.
- Maintains the sample at a consistent temperature using an integrated electric heater, preventing condensation within the probe.
- Designed with a heated aspirator for efficient sample circulation and transport.
- Single process connection for both sample extraction and return, simplifying installation and reducing costs.
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- Features a centrifugal chamber and demisting mesh pad to remove sulfur fog, mist, and liquid, effectively reducing the sulfur content before gas transport.
- The ASR900 model incorporates multiple functions (condenser, coalescer, aspirator) in a temperature-controlled body, preventing sulfur deposition and clogging.
- Can be fully disassembled for maintenance without exposure to process gas, ensuring safe handling and easy servicing.
- Sulfur reduction at the sample point allows flexibility in locating the analyzer system and minimizes the risk of sulfur-related issues in the downstream process.
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Operational Environment
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- Suited for environments with high concentrations of toxic gases like H₂S and SO2, where safety and precision in handling corrosive and hazardous gases are critical.
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- Ideal for sulfur recovery tail gas applications where sulfur management is essential to prevent process disruptions and equipment damage due to sulfur accumulation.
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Summary
The HAG Probe is optimized for safely handling and analyzing corrosive acid gases, focusing on ease of maintenance and preventing sample condensation.
The ASR Probe excels in managing sulfur in gas streams, specifically designed to reduce sulfur vapor and handle liquid sulfur, making it essential for sulfur recovery processes.
For more info about our sample probes refer to these resources:
ASR data sheet
How the ASR sample probe works
HAG data sheet