o Jamming of shaft bushing, on which plate is mounted
o Bear & tear of plate
o Uneven Ventilation pressure. Change in Bag Filter suction pressure affects
the results.
9.4 Clinker Weighing System in Cement Plants
The online weighing system of produced clinker was not available before some
years ago. The only method to calculate the quantity was multiplying the factor
of loss of burning of raw meal with the total fed raw meal in kiln. The introduction
of Pan weigher made the system of clinker booking in more accurate way than
conventional methods.
PRINCIPLE OF OPERATION:
The weigher machine is installed below the Deep Pan Conveyor (DPC), like the
belt weigher under belt conveyor. The principle of operation is same as mentioned
above in Belt weigher section.
Pan weigher with four active load cell with accuracy +/- 0.25% shall be installed
below DPC, meant for transportation of clinker from cooler to clinker storage silo.
In addition to this a 500T capacity steel hopper, with weighing arrangement on
3 active load cells, is installed for unburnt clinker storage. This makes the system
a combination of Pan weigher & Weigh bin for more reliable & accurate way of
knowing total produced clinker, as the on line calibration cross checks of pan
weigher can be carried out at regular intervals.
Following combinations are commonly used for weighment purpose –
- Only Weigh Feeder
- Weigh feeder with weigh Bins
- Only Belt weigher
- Belt Weigher/Pan weigher with Weigh Bins
A. Recommendations:
- Weigh feeder reliability and consistency are possible with weighing hopper
because online calibration and monitoring of system accuracy can be done
with the combination of weigh feeder and weigh hopper only.
Hence it is recommended to install weigh hoppers along with weigh feeder
which also avoid problems of high level, low level, over flow of the material,
calibration problems etc. - It is also clear that belt weigher /Pan weigher alone cannot perform as
guaranteed by supplier & also not a reliable solution without weighing hopper.
Because online calibration and monitoring of system accuracy is only possible
with combination of belt weigher and weigh hopper only.