AEC Continuous Vacuum/Pressure Conveying Systems - Manual (Page 40)

Single- and Dual-Blower Continuous Vacuum/Pressure Systems Page 39
5 Startup, Shutdown, and Operation
5-1 Equipment Cycle
Systems with dual blowers have a slightly different equipment cycle than systems with
single blowers. Refer to electrical schematic and panel layout drawings included with
your system for more information.
A description of the cycles for each type follows:
SVP — Single Blower Vacuum Pressure Systems
When the system is started, the single vacuum/pressure blower and the rotary airlock
activate. The blower draws air from the atmosphere (goes into a vent cycle) and starts
to purge the pressure side material line for a set period of time as determined by the
vacuum on delay timer. After a set time period, the vent cycle ends and material is
drawn into the cyclone, where it is stripped from the conveying air and drops into a
rotary airlock.
The airlock allows material to pass to the pressure side of the system where it is blown
to the destination. The SVP blower replaces CVP/CPP blowers in single blower
vacuum pressure systems, but the load cycle remains the same. See Figure 11 on Page
40 for more information.
When the system is stopped in a non emergency situation (purge stop), the blower goes
into the Vent cycle and continues to purge the material in the pressure side of the
material line, while no material is drawn into the cyclone separator or the filter receiver.
The purge time controlled by the purge timer, adjustable from zero to ten (0-10)
minutes. You must restart the system after the purge cycle.
When level sensors in the cyclone or at the destination point detect a high level
condition, the vacuum unit goes into idle until material levels decline. The time for the
idle state is controlled by the Vacuum On delay timer, adjustable from zero to ten (0-
10) seconds. The system then returns to the conveying cycle. An automatic shutdown
module shuts down the vacuum/pressure blower and rotary airlock after a preset period.
The emergency stop button on the control unit shuts down all units in the system. The
system also goes into emergency stop when the high pressure sensor on the pressure
outlet opens.