The system makes it possible to measure the calorific value of coal directly on the belt conveyor using a combination of measurement of ash content by radiometric method and microwave measurement of coal moisture.
The detection system consists of two separate measuring frames for the measurement of ash content and humidity installed on a belt conveyor. Frames can be installed directly on the belt conveyor or as part of the measurement on the sampler.
Technical data
Conveyor belt width mm
unlimited
Measurement range
according to customer's requirements
Conveyor belt speed m/s
unlimited
Granularity of measured coal
standard up to 90 mm (other values on request)
The height of the coal layer on the belt
standard 40-300 mm (other values on request)
Protection
IP65 standard (higher on request)
Working temperature (detection degree)
-20°C to +50°C as standard (other temperatures on request)
Weight (detection degree)
according to the width of the belt conveyor (average 120 kg)
The detection system consists of two measurement frames for ash content measurement and moisture measurement installed on the belt conveyer. The frames can be installed directly on the belt or as a part of the coal sampler.
The ash content detection stage evaluates the coal non-combustible content according to differences of attenuation of two gamma beams of different energy passing through the coal. It contains two radiation sources in protecting container placed under the belt, radiation detector and intelligent mathematic unit. The measurement radiation beam is directed through the conveyer belt, while the presence of persons nearby the device is not limited in any way.
The design of the detection stage is focused on maximum reliability and safety. The moisture detection frame contains the transmission antenna under the belt, reception antenna above the belt and the evaluation unit. The unit determines the moisture based on the attenuation and phase shift of the microwaves. Depending on the type of coal, the antennas can be arranged in different position. The evaluation unit is interconnected with the control stage of the system.
The control stage provides user-friendly operational interface with displaying the data on the touchscreen panel. The control stage can be installed directly in operator workplace. Inside the control stage box, there are accessible terminals for connection of communication interfaces and other analog or digital inputs and outputs. It is possible to connect several remote terminals to the control unit and so distribute the data to different places if needed. The terminals can handle several tasks according to the use of each operator workplace.
Measured and diagnostic data are stored automatically for reverse evaluation. With suitable calibration the system can be used for any type of coal, the only limitation is the maximum granularity.
The range of usable layer height is achieved by interconnection of the measurement methods and also wide dynamic range of the microwave device.
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The calorific value is determined based on the combination of ash content and moisture content value online measurement.
Ash content is available as individual value.t is available as a separate value.
Last valid moisture value is used in case that the measured layer does not conform to the suitable limits.
Based on the mathematical profile model of the conveyer and measured layer thickness value.
(tons per hour)
enables to calculate average calorific value and overall quantity value between START and STOP signals.
The measurement is blocked if the technology is out of operation.
The device can be calibrated for several types of coal.
Calibration data switching can be handled from the control panel or by remote signal.
Ensures proper operation after power drops.
LAN network connection is available for remote management,
data acquisition, maintenance and diagnostics, ModBus RS485
for PLC uplink connection. Measured values converted
into the analog outputs.
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Depending on the location and parameters of the coal, it is possible to place the detection stages in different ways.
In the basic configuration, both detection frames are located simultaneously on one belt conveyor.
In case that the coal layer or coal granularity is not suitable for the moisture measurement, the system should be placed near the sampler and the moisture measurement frame should be placed at the crushed coal sample transport system.
Such design can be used almost for any kind of coal in case of suitable sampler setup.
Would you like to find out more about the products? Contact us by e-mail or phone. We will arrange a meeting to present our ENELEX product portfolio in detail.
