PCME - Passionate about Particulate

The PCME STACK 602 is a cross-stack optical system used extensively for compliance measurement in the Power, Steel and Cement industries. With TUV approval for EN 14181 and EN 13284-2, the instrument is primarily used in applications with electrostatic precipitator boilers, calciners and large diameter emission stacks. The PCME STACK 602 can be used in processes where either direct Opacity (and extinction) measurement is required, or dust concentration measurement for specific applications via calibration against the Standard Reference Method.

Traditional Opacity instruments measure the intensity of received light; PCME's patented DynamicOpacity™ Ratiometric Opacity technology instead measures the temporal variation (rate of change) in light, or Optical Scintillation. This offers a significant advantage over traditional Opacity methods, as the ratiometric measurement is unaffected by lens contamination allowing the instrument to operate with lens contamination exceeding 90%, therefore greatly reducing costly process intervention for lens maintenance and servicing.

• Automatic Zero and Span checks to monitor for instrument integrity
• Extended maintenance intervals due to reduced sensitivity to lens contamination
• Sensor lenses are accessed in-situ for lens cleaning, ensuring correct alignment of transmitter and receiver even after maintenance
• Entry and Standard control unit with advanced graphic and user interface screens, features including alarming, graphical trending, data logging, 4-20mA output.
• PLUS control unit option for sensor networking (up to 16 sensor channels) via industry standard Modbus, multiple inputs for external devices (e.g. for Temp and O₂ normalisation)

The PCME STACK 602 supersedes the SC600T, a similar DynamicOpacity™ Ratiometric Opacity instrument.

Extended Maintenance Intervals & Lens Contamination Compensation

DynamicOpacity™ Ratiometric Opacity instruments are often used to replace Opacity instruments which typically require extensive maintenance and servicing. As the instrument is measuring the ratio of signal scintillation to absolute light intensity, the PCME STACK 602 continues to operate with lens contamination of up to 90%. This is because both the reduction in light intensity and the variation in intensity caused by lens contamination are affected by the same proportion, resulting in no net effect. In contrast with traditional Opacity measurement, the DynamicOpacity™ Ratiometric Opacity method also compensates for potential misalignment or aging of the light source.

Air purge should be connected to the transmitter and receiver heads to provide a positive displacement of air away from the lens surfaces, however since air usage is in the order of 30-60 litres/minute it is economical to use plant instrument air rather than install dedicated air blower systems.

Automatic Zero and Span Checks

The PCME STACK 602 includes automated electronic Zero and Span checks which monitor instrument integrity. These checks simulate the operation of the instrument and permit any internal instrument problems to be self-detected. Span checks for the CEM are implemented automatically and are performed by varying the light intensity in the transmitter head. The zero check involves measuring the variation with no transmitter light present. These checks are carried out automatically every 3 hours.

Simple Setup and Maintenance

DynamicOpacity™ Ratiometric Opacity instruments use a diffused transmitter which emits light at a range of angles from the transmitter source. Combined with the ratiometric measurement algorithm this means that the alignment of transmitter and receiver are less critical than with traditional Opacity instruments, and consequently do not require elaborate alignment procedures during installation.

Optical alignment aid makes the set-up and alignment of transmitter and receiver very quick and easy

Additionally, the transmitter and receiver heads are designed so that the lenses can be accessed and cleaned without the need for disconnecting flanges from the stack, ensuring correct alignment even after maintenance intervention.

Process Conditions

The PCME STACK 602 is suitable for:

• Stacks after bag filters, cartridge filters, cyclones, or no filter
• Electro-filters, e.g. electrostatic precipitators
• Non-condensing / dry flue gases*
• Variable flue gas velocities, including low velocity flue gases
• Variable particulate size and type

* For wet / condensing flue gas applications see PCME STACK 181 WS.

Typical Applications

The PCME STACK 602 is used to monitor emissions from the following types of processes:

• After Electro-filter abatement plant
• Power industry, Coal Fired Boiler Plant
• Cement kiln abatement
• Gypsum industry, Calcinators
• Large diameter stacks
• Processes regulated in terms of Opacity / Extinction