In this example a cement silo was discharging into transfer pods for dense-phase transfer. The plant routinely recorded the back-pressure from these pods as a measure of their transfer efficiency (basically, the higher the pressure could be maintained from each 2 min blow-down cycle the more cement was being transfered.
Inventory transfer rates are evidenced by the pressure logs. As shown below
prior to the PMT trial had slowed to a trickle and essentially stopped
discharging. This is “empty condition” is evidenced by looking at the Plant’s
back-pressure graph below, where the pressure mostly drags along the 1 psi
baseline.
As seen on the next graph -- Multiple attempts on subsequent days
confirm the silo was no discharging the bin-bottoms.
See below -- What a difference PMT
makes !
Good pumping rates are indicated, by equipment operating in the range of 2.5 to
5 psi.
Baseline pressures typically from equipment changeovers or high-level signals
from down stream silos.