AMEPA chronology - Coal Flow Measurement
Service - Coal Flow Measurement
Field of application - Coal Flow Measurement
Distribution partner - Coal Flow Measurement
References - Coal Flow Measurement
Health and safety system - Coal Flow Measurement
CFM - Coal Flow Measurement
ESD - Electromagnetic Slag Detection
OFIS - Oil Film Thickness Measurement
OFM - Online Oil Film Measurement
RSD - Residual Steel Detection
SRM - Surface Roughness Measurement
TSD - Thermographic Slag Detection
MFM - Mould Flow Measurement
SFM - Ladle Purging Monitor
Slagmeter - Slag Thickness Measuring
Wavisurf - Online Waviness Measurement

Pulverized Coal Injection (PCI) systems should assure small line-to-line deviations in order to maintain a ‘healthy furnace’. Reality is often different; consequently optimal injection rates are not reached. The CFM flow meters are the first step towards optimal injection rates: measure the flow, control it, increase it to the optimum.

Technical data


Coal injection (PCI) into the blast furnace meets the need for cost reducing and minimizing the environmental impact of steel production.

While pursuing the benefits of replacing expensive coke by cheaper injection coal the blast furnace stability and overall productivity must be sustained. The limitation of coal injection is the necessity of a complete combustion of the coal particles. Unburned char remains are the result of overloading individual tuyeres beyond the ideal calculated replacement ratio of coke by injected coal.

PCI into the raceway of a blast furnace

PCI into the raceway of a blast furnace

Only by strictly avoiding unburned char particles a high permeability and a reduction of gas consumption can be achieved. This is mandatory for the blast furnace stability and productivity.

Tests at existing PCI installations using static distribution show large deviations between individual lines. Overloading individual tuyeres with negative effects on the permeability is unavoidable in this case.

Therefore, a reliable uniform distribution of injected coal is the top priority.

A well designed pneumatic layout of the PCI installation is the precondition but due to ever changing pneumatic conditions during operation only an individual closed loop control for each tuyere makes it possible to achieve a truly uniform distribution.

Controlled injection with CFM

Controlled injection with CFM

The CFM is the flow meter of choice in this application – the reliable, self recalibrating measurement equipment fulfills all requirements for perfect control of injection in all different plant layouts.

Integration of CFM control in different plant layouts

Integration of CFM control in different plant layouts

Today over 1000 CFM units are in operation. Examples of customer results:

  • Reduction of deviations from over +/-20 % to less than 2 %
  • Increased PCI rate by 55 kg per THM (ton of hot metal)


For the CFM, a capacitive measuring method is being used, taking advantage of the different dielectric characteristics of coal powder (εR) and of the conveying gas (ε0).

Each CFM sensor consists of two different sets of electrodes. The first set measures capacitively the powder coal concentration present in the injection line. The second set of electrodes is needed to measure the velocity of the particles, using a

capacitive-correlative method. A microprocessor, integrated in each CFM device, calculates the actual flow rate from the product of these two values, the geometric property of the conveyor line and the material dependent calibration factors.

Some features making the sensor unique:

  • Independence of the coal distribution in the conveying pipe through the helix-design of the electrodes
  • Immunity against pressure peaks by using non-ceramic tubes
  • Easy parameter setting and documentation via a bus communication between all sensors

Technical data

Measuring tube

  • Fiber reinforced Epoxy or ceramics
  • Pipe diameter DN15 to DN 150


  • Self contained inside flow meter
  • No further installation of electronics in electrical room necessary
  • Optional integrated PID controller for direct valve control

Mechanical construction

  • Steel pressure body
  • Cast aluminum electronics case
  • Cable glands or system connectors for electrical wiring

Ambient conditions

  • Suitable for outside installation (IP67 rating)
  • Temperature -20 °C – +40 °C (-4 °F – 104 °F)
  • Extended temperature range up to +70 °C (158 °F) available

Media conditions

  • Pressure-less to more than 50 bar (725 psi)
  • Media temperature up to 90 °C (194 °F)
  • Extended temperature range up to 450 °C (842 °F) available


  • Centralized via CAN-Bus
  • Automatic recalibration option

Flexible signal inputs/outputs

  • Digital-Link protocol converter for various fieldbus standards like Profibus, Profinet, Melsec
  • 4-20mA current loops for analog interfacing
  • Optional interface for direct valve control

Power supply

  • 24V DC +/- 20%, max. 20 W

Installation options

  • Flanges according to several standards (DIN/EN, ASME, JIS) or customer specific
    Conventional wiring or tailored EasyWiring system with system connectors


  • ATEX Ex II 3D EEx T5 / exproof ATEX Ex II 2G EEx d IIC T6 (EC/94/9)
  • Pressure equipment directive (97/23/EC) or ASME Code


  • Weiser, R.; Braune, I.; Matthes, P.: „Control Blast Furnace Pulverized Coal Injection to Increase PCI Rates”. AISTEC Conference, 2006, Cleveland, Ohio, USA Download