Coal Flow Online Measurement & Balancing

In the Pulverized Coal Boiler, the coal pipes layout varies and each coal pipe has a different length and layout to the burner. With the nature of flow loss and resistance, the coal flow will be unevenly distributed among different pipe levels to the burner.

Without clear visibility on monitoring the coal flow and coal velocity continuously, the plant operator will not be able to perform tuning effectively to balance the coal flow.

In addition, the characteristic of coal varies as well, i.e. from Bituminous to Subbituminous or low rank. Due to the change of coal feed supply, the moisture level and the coal quality will be different. This prompted for the operation team to conduct boiler tuning as soon the coal feed changes. The schedule can range from monthly, quarterly or even longer.

BALANCING COAL FLOW IS A PRIMARY OBJECTIVE OF
COMBUSTION OPTIMIZATION

Advanced Coal Flow Measurement System

The Coal Flow Measuring System is specifically designed to measure the coal mass flow, velocity and temperature of the coal pipe. It measures the pulverized coal distribution to each burner which helps to balance coal amount in order to avoid combustion issues caused by high LOI.

Main features:

• The Mass Flow Meter is measured with microwave sensor and the velocity is measured by electrostatic measurement.
• It can rapidly and accurately measures the coal flow up to 8 pipes per mill (there is no limitation for the number of mills).
• It is drift free and independent from pressure and temperature operation in a wide range.
• It provides software tool to communicate with each connected sensor for monitoring and diagnostic function.
• It also comes with a visualization package that displays the flow and coal flow distribution in bar graphs and a continuous line recorder.

The data can be stored for at least one year on continuous running mode and online tuning can be performed whenever necessary to optimize the coal flow.

Online Coal Flow Balancing Valve

The coal flow on the on each pipe can be regulated by a dedicated coal flow balancing valve. The unique design improves the homogenous coal flow thus reducing the coal roping effect and achieving coal flow balancing. The valve can be controlled remotely using pneumatic/ electric actuator

Benefits:

• Improved combustion efficiency and emissions
  • Improved heat rate (1% – 3%)
  • Less CO2
  • Less NOx and CO emissions (-5% to -15%)
  • Less LOI
• Less Slagging and less boiler cleaning demand
• Positive effect on availability and maintenance
  • Less downtime
  • Less Boiler wall corrosion.