Asphalt and Inert Materials Drying Units
Asphalt production process requires all inert materials to get dried into orbital drying drums at temperatures about 160 Celsius.
The fuel that is used for this process is mostly mazut including sulphur about 1-3 %.
The drying process usually produces significant amounts of dust.
Older production units used to use cyclones or wet scrubbers in order to collect the dust. Unfortunately those systems didn’t work as expected, so they don’t overlap modern standards of dust emission. Usage of de-dusting filters seems to be the best solution because they not only overlap today’s standards but also the future ones.
Extra care must be taken when choosing the filter-clothe material that will be used on the de-dusting unit. Those materials not only have to be durable on high temperatures but also on acid environments due to sulphur existence inside the fuel.
A double temperature check automation system have to be installed on a de-dusting unit in case the temperature exceeds the limits of the filter clothe and also in order to avoid the waste gases temperature falls under the dew point.
Reconstruction of an existing Bag filter for dedusting a raw material dryer in an asphalt mixing plant