On-Belt Coal Analyzers (BCA) in TPP

Analix On-Belt Coal Analyzer consisting of BCA-6

Analix On-Belt Coal Analyzer consisting of BCA-6 (Analix) and MA-500 HD (Moistscan ®) in AES Maritza East 1

Benefits of using the On-line Coal Analyzers BCA in TPP

  • effective on-line control of the quantity and quality of the incoming coal;
  • optimizing burning process trough on-line quantity and quality control of the coal feeding the boilers;
  • avoiding critical situations caused by out of limits coal caloricity.

In general the benefit of using BCA is reducing of the production costs

The pay back period for BCA instruments is about one year of operation.

BCA in Bulgarian TPPs

Analix have produced and installed 19 on-belt coal analyzers (BCA) in almost all Bulgarian TPP. 13 of them work in the three lignite burning TPP - AES Maritza East 1, Maritza East 2 and Contour Global Maritza East 3. Also we have our BCA instruments installed in some smaller TPP burning brown and black coal.

BCA-5 in TPP       BCA-4 in TPP

BCA-5 in TPP “Contour Global Maritza East3” BCA-4 in TPP “Maritza East2”


Our last project for Coal Quality Control System was realized in the newest Bulgarian TPP – AES Maritza East 1. In this system as in the system produced by Analix 5 years ago for ENEL Maritza East 3 (now property of Contour Global), we integrated together with our ash analyzer under a common control and data processing, the Callidan Instruments Moistscan® on-belt microwave moister meters.


Radiation safety of Analix On-Belt Coal Analyzers

Our instruments are permanently checked and licenzed by the Bulgarian Agency for Nuclear Regulation.

All measurements done by all kind of regulatory officials (Agency for Nuclear Regulation, Ministry of Health, Ministry of Internal Affairs, etc.) confirm the complete radiation safety of our radioisotope on-belt ash-analyzers.

The staff passing by, or working around as closed as possible, do not obtain any irradiation.

There is no one case the radiation for people working there or passing by to be higher then the native radioactive background for that area.

Accuracy of BCA

The standard error for ash content:

  • 0.5%  for the range   5.0 ÷ 15.0%
  • 1.0%  for the range 15.0 ÷ 25.0%
  • 1.5%  for the range 25.0 ÷ 35.0%
  • 2.0%  for the range 35.0 ÷ 50.0%

For total weight the accuracy is about 2 % for quantities more than 500 t.

Coal Quality Control System

The Coal Quality Control System contains the following main modules:

  • On-belt coal analyzer
  • Interface module
  • Computer station
  • Profibus gateway
  • Interface operator station (terminal)
  • Router

The on-belt analyzers, which measure coal ash content and moisture, are mounted on conveyor belts next to Coarse crusher and next to Fine crusher (one analyzer unit per conveyor belt). Each on-belt analyzer communicates with computer station for data processing. The computer stations transfer processed information to interface operator stations – one for the analyzers next to Coarse crusher and one for those next Fine crusher. Software application ‘Calorimeter’ ver. 2.0, installed on the interface operator stations (terminals), ensures measurements data visualization and reports creation.

Presented system provides continues measurement of coal ash content and moisture, also of belt load and total coal quantity. By the software the coal caloricity is calculated on-line as current and as average value. Appropriate user interface presents all the information provided by the system and it is also sent to the power plant information system in the required data format.

The belt ash-content and moisture analyzers (radioisotope ash-content analyzer BCА-5 and the microwave moisture analyzer Moistscan) operate fully automatically and operator service is not required, except in case of failure or damage. They are designed and built in such way that they do not require adjustments and service during normal operation. The current maintenance includes only periodical status check and empty belt normalization.

Block scheme of CQCS

Principal block and connection scheme of Analix Coal Quality Control System