Tunable Diode Laser Spectrometers

TDLS contributes to improving your work.

Features of TDLS Series

• Measurement of oxygen, carbon monoxide, methane, ammonia, moisture, carbon dioxide, and other gases in seconds
• No sampling equipment is required for the majority of measurements, eliminating a large portion of maintenance
• The only process TDLS platform capable of measuring up to 30m
• Measurements can be made in high temperature, high pressure, corrosive/abrasive, and high dust conditions because the sensor does not come in contact with process gas
• Ideal for critical applications with a SIL-rated fast speed of response
• Maximize efficiency, consider the environment, and reduce emissions of CO, NOx, etc.

Settling with legacy technologies

In a world which is continuously evolving in the direction of increased process optimization while maintaining safe operating state, it’s difficult to retain a competitive advantage without adopting new measurement techniques to stay cutting-edge.
>>> Principles

TDLS provides a safe, efficient and cost-effective solution.

Basic Concept and Measurements of Laser Gas analyzer

Measurement principle of a laser gas analyzer

The tunable diode laser absorption spectrometers (TDLAS) operate by measuring the amount of a laser light that is absorbed as it travels through the gas being measured. Because the sensor does not have contact with the process and there are no moving parts, maintenance is minimized, which decreases downtime and reduces the long-term cost of ownership (LTCO).

The attenuation due to IR absorption is determined by Lambert Beers'Law.

Lambert Beers'Law

Absorption of IR-Radiation

A highly reliable measurement in varying steam conditions is possible due to Yokogawa’s unique spectral analysis methodology

Yokogawa Electric's original spectral area method is hardly affected by interferences of other gases, and it can be measured with high accuracy by temperature and pressure-compensation.

An integral reference cell retains measurement integrity, even in low absorption streams

The use of a reference cell keeps the peak position locked during trace measurement when the absorption signal is weak.

Up to 50 days of historical data, spectra, and all setting changes are accessible

This data is useful for remote troubleshooting of process issues long after upsets have occurred.

Increased measurement capabilities have allowed our users to safely increase operating efficiencies while reducing emissions.

• In situ analysis
  Improves safety and process controlling capability due to near real time response
• Tunable laser
  No moving part so that no consumable exists
• Non-contact sensor
  Operates in a harsh environment and minimizes maintenance
• Long-pass optical sensor
  Represents the entire process measured whereas inserted or extractive measurement reflects only a spot.

The TruePeak Tunable Diode Laser Spectrometers operate by measuring the amount of a laser light that is absorbed as it travels through the gas being measured. Involving no sensor contact with the process and no moving parts, it leads to a high mean time between failures (MTBF) and hence a low long term cost of ownership (LTCO).

Fired heaters are integral to industrial processes, including hydrocarbon processing and power generation. Specifically designed for the reaction of fuel and air to produce extremely high gas temperatures, heaters transfer this energy to potentially highly flammable process fluids via heat exchangers. They consume large quantities of fuel, produce large quantities of emissions and are a potential safety hazard to personnel and plant.

Yokogawa TDLS analyzers help control fired heater combustion with ever greater accuracy and reliability. There are measurable rewards for operating fired heaters at Low Excess Air (LEA) levels. In LEA combustion control, the lowest level of fuel is consumed and the products of combustion are cooled the least by unused excess air.

The cost benefits of these efficiencies are considerable, with just a single percentage saving in fuel enabling savings of tens or even hundreds of thousands of dollars per year. Controlling air levels just above the point at which incomplete combustion starts also enables the "cleanest burn," helping plants meet environmental emissions requirements. This in particular reduces the emission of NOx.

Combustion

Maintaining operational efficiency in your furnaces to maximize throughput and minimize fuel consumption while ensuring safe operation is truly a difficult challenge.

Conventional analyzer technologies, such as zirconia and catalytic bead measurements, are point style measurements which can fail to completely capture what is happening in your furnace. In addition to being a potential ignition source, zirconia can have its reading lowered in the presence of combustibles. COE analysis has its own issues due to the minutes-long response time required for typical breakthrough levels in the thousands of ppm in the radiant section of a fired asset, and often require a separate sensor for CH4 measurement. Such issues can have a large impact on how safely your furnace is being operated.
The modern unit operator needs access to the most trustworthy data available to quickly mitigate the occurrence of an unsafe condition if they’re going to optimize asset performance.

The introduction of Yokogawa’s Tunable Diode Laser Spectrometer (TDLS) technology allows for the real-time, in-situ, interference free, reliable, and accurate measurement of oxygen and CO to maximize efficiencies.
It’s a major advance in supporting the entire facility in operating the asset safely and efficiently.

Features and advantages of Yokogawa's TDLS technologies

• Real-time data for control
  The efficiency is maximized because and safely improves operation efficiency as well as emissions because the air/fuel ratio is always optimized
• Laser analysis
  The new technology enables the adoption of industry best practices.
• Non-contact sensor
  Operates in a harsh environment and minimizes maintenance
• Long-path optical sensor
  Long path average measurement eliminates hot spots hence enables long lifetime of the heat exchange pipe (minimization of costs).

Safety / Process

When it comes to understanding what is happening in your furnace, a reliance on limited data outputs from conventional analyzer technology places a greater onus on the skills of the operator.

TDLS technology reduces the burden on operator competence and the potential for human error by delivering the most trustworthy data on the entire furnace as quickly as possible for optimal asset efficiency and safety.

It’s imperative you have the ability to detect, measure and control LOC (Limiting Oxygen Concentration) to ensure the safety of your facility and your workmates.

Our customers' operating safety and operating efficiencies have enabled us to reduce operating costs and reduce CO₂ and NOx emissions.