Unburned Carbon Online Analyser (UBC-2000).
What’s the benefit?
- The UBC-2000 provides automatic and continuous online information about UBC levels for combustion efficiency, coal mill performance, classifier assemblies and the quality of the fly-ash in changing conditions.
- It has a short response time due to placement close to the combustion zone, which allows the information to be used directly in the boiler control.
- The unit is a cost-effective solution that is easy to maintain.
- The unit provides accurate content of UBC which is material in setting the correct price of post-combustion fly ash.
- The unit, installed in power plants all around the world yields accurate results despite variations of ambient temperatures, thanks to a built in temperature controller.
- By providing a physical fly ash samples, at request, the samples can be analysed in a laboratory. This allows for additional information regarding the combustion process, which can be used to further optimize the efficiency of the power plant.
What does it do?
The Unburned Carbon Online Analyser 2000 (UBC-2000) provides the operators with automatic and continuous online information about the amount of unburned carbon (UBC) in post-combustion fly ash as well as physical samples for further laboratory testing. The UBC-2000 is typically used on large electric boilers firing with hard or brown coal. The UBC-2000 utilizes its infrared technology especially suitable for power plants combusting coal with a lower variance in properties due to sourcing from similar coal mines/ excavation points). The UBC-2000 can be placed in the flue gas duct close to the combustion zone allowing the information to be used directly in the boiler control room. M&W was the first company in the world to invent, patent and install the UBC online analyser in the world.
How does it do it?
The UBC-2000 consist of a control unit, an analyser unit and a collector unit. The measurement principle is based on the established fact that infrared reflection properties relates to the amount of UBC in the ash sample. The fly ash sample is illuminated with infrared light and the reflection is a measure of the amount of UBC in the sample. The signals from the reflection are processed in a microprocessor and sent to the control unit.
The period of a sampling cycle depends on the flow of fly ash, and ranges from 3 to 15 minutes. The samples are obtained before the fly ash reaches the electrostatic precipitator, which gives a faster response time compared to traditional instruments. This rapid data acquisition allows for use directly in the boiler control, or as key parameters for the operators to quickly adjust the combustion process. By allowing the samples to be either purged or collected in a sampling bottle, the operator may choose to collect samples after the analysis, which can be used for laboratory purposes.
What are the technical details?
Power supply: 230V/50Hz or as required
Power consumption: 600 Watt
Air supply: Min. 6 bar clean oil-free air
Sampling time: 3-15 minutes, depending on flow
Measurement range: 0-20% carbon in weight
Accuracy: +/- 0,5% residual carbon between 2% and 7% residual carbon
Measurement output: 4-20mA, isolated current loop, 4mA=0%, 20mA=20% carbon
Dimensions: (WxHxD): Sampling unit: 800x760x230 mm
Control cabinet: 600x750x350 mm
Weight: Sampling unit: 35 kg
Control unit: 80 kg
Ambient temperature: Sampling unit: +5 °C – +45 °C
Control unit: +5 °C – +45 °C
The Sampling Unit
The pumping power is provided by utilising the pressure difference between the ambient and inside of the duct. The pressure difference drives an adjustable ejector. This design means that extraction velocity automatically adapts to changes in the flow rate in the duct.
The measurement principle is based on the established fact that infrared reflection properties relates to the amount of UBC in the ash sample. The fly ash sample is illuminated with infrared light and the reflection is a measure of the amount of UBC in the sample. The signals from the reflection are processed in a microprocessor and sent to the control unit.
The Control Unit
The control unit undertakes the processing of the transducer signals and controls all functions of the individual RCA components. An operator’s control panel with display is located on the control cabinet front. The RCA-IR can be fitted with different communication technologies e.g. Bluetooth, WIFI and LAN, and a remote access system is also implemented.
The UBC-2000 is also available for installation in the hopper using a different extraction mechanism.
Nota Bene 1
The RCA is “only” an on-line trends measurements. It has to be verified with a reference. This could for instans be once every week. The big advantage of the RCA is that between the operators manual laboratory meassurement, continously, get a trending.