BPS Industrial dust collector products
Pulse Jet Baghouse Dust Collectors are also commonly spelled Pulse-Jet Dust Collector or PulseJet Dustcollector.
Cliff Mansfield
To correct this problem at these plants I added a “manual”
pulsing mode so that we could set the baghouse up to be pulsed any time the plant
is running, regardless of the “pressure differential”. This way a constant amount
of baghouse dust is being added to the mixing process. I used the manual settings
on the pulse card to set the “pressure differential” to 4”. The downside of this
is that the plant operator must adjust the pulse card himself to assure the “pressure
differential” stays in the range he wants. This “inconvenience” is far outweighed
by the improvement in dust control and improved mix consistency. This change can
be implemented at your plant for perhaps $500, maybe less. It simply requires
some wire, a switch and someone to do it.
I’ve changed many plants, both drum and batch, to this configuration and have
seen a significant improvement in mix quality and more consistent sample results.
A secondary issue that contributes to dust related sample problems is start-up
and shut-down protocols. When we start our plants the majority of them will exhibit
an elevated level of dust for a short period of time. This material is added to
our mixing process regardless of the amount of aggregates coming in. On a batch
plant this can contribute to surges of fines into #1 bin, especially if the plant
doesn’t use a dust run around system. On a drum plant it means we have to waste
material onto the ground through our reject chute. During daily operations a plant
can be started and stopped many times which leads to a considerable amount of
rejected material. It also leads to poor quality mix for a short period of time,
due to an elevated level fines. To combat these problems I advocate the use of
hot-stop or mid-stream stops during normal daily operations at all plants, including
batch plants.
A hot-stop is performed as follows: When the time comes to shut down you would
first switch your burner control and asphalt control (on a drum plant) to manual,
note the burner position, then kill the feeders. When the aggregates stop falling
into the dryer, kill the dryer, the burner, the fans, divert the oil on a drum
plant, turn off the baghouse pulse control and any associated blowers/augers,
then close the damper.
To restart the plant: Start the main fan and the burner fan. Once the burner controls
go through their ‘purge’ cycle you can light the burner, open the damper and start
the aggregates. When the rock spills into the dryer you would start the dryer,
turn on the baghouse pulse control and any associated blowers/augers, then either
restart the oil injection on a drum plant or restart the batching process on a
batch plant. Next, ramp your burner up to the last run position. You are now back
to full production in less than two minutes.
If you do these operations correctly you should have no wasted materials and a
very smooth transition from running to stopped and vice versa. One note: The temperature
of the aggregates in your drum is what controls how long you can remain hot-stopped.
On hot summer days I’ve set for as long as three hours with little adverse affect.
On a cold, windy day in Alaska the down time will be considerably shorter. Given
the improvement in mix quality due to even fines distribution and considering
the abbreviated start-up time, hot-stops have become a matter of course in my
training regimens.