Application Workshop - Clinker Cooler Speed Control
07/01/2011 VEGA Controls Ltd
Also used in other processes under difficult conditions like high pressures, corrosive/toxic fluids, dust, vapors etc.This application looks at using non-contact radar technology to optimise the cooling process on a clinker bed.
Main Application Details:
Level Monitoring with non-contact radar transmitters.
Product : Clinker
Vessel: Cooler grate after rotary kiln
Height: 3.5 m
Temperature: 1300°C
Environment: High dust generation
Application:
In a cement works the clinker is discharged from a rotary kiln and then cooled on a moving grate by passing air through it. The speed of the feed rate and air flow regulate the cooling process. The thickness of the clinker 'bed' is often measured indirectly by temperature probes or back pressure of air flow. A rise in temperature or back pressure is usually proportional to the clinker bed thickness, but it can be due to changing material size. The grid speed and the flow of the cooling fans are adjusted to optimize the cooling process. Changing material size, high temperatures and dusty atmosphere make these measurements very challenging to keep consistent.
Solution:
Air flow and air pressure measurements in the cooler are made respectively by differential pressure mounted on orifice plates and ceramic cell pressure transmitters. In addition to this pressure measurement, a high sensitivity radar level sensor can also be used to directly measure the thickness of clinker bed, and thus improve the efficiency of the cooling air control. The radar is mounted above the cooler, with a bent antenna extension and integrated cooling air-purge system to protect the electronics against high temperatures and keep build-up out of the antenna.
Technology:
The radar antenna generates millions of very short 1 nano second microwave pulses every second. Each pulse is transmitted to and reflected from a product surface. The elapsed time period between transmission and reception of the signal at the speed of light is measured and calculated as a distance. This continuous stream of pulses gives real time level information updated and evaluated many times a second. Microwaves are unaffected by temperature, pressure, air movement and virtually all vapours, dust or gases.
Ceramic pressure transmitter are very robust against abrasion by dust particles.
Benefits of using non-contact radar in this type of application:
- Direct measurement - independent of particle size and product temperature (radar sensor)
- Universal set-up for all level and pressure transmitters
- Radar sensor antenna has integral cooling/cleaning.
- Flush ceramic pressure transmitters more robust and abrasion resistant
For further information, please contact:
VEGA Controls Limited
Kendal House, Victoria Way, Burgess Hill, West Sussex, RH15 9NF
Phone: (+44) 01444 870055 Fax: (+44) 01444 870080
E-mail: info@uk.vega.com
Web: www.vegacontrols.co.uk
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