9-Use Of Proportioning Valves; Initial Startup - MAGUIRE NOVATEC VL Series Instruction Manual

9- USE OF PROPORTIONING VALVES
Proportioning valves are a convenient method for introducing regrind into the process while
vacuum loading of virgin material. The proportioning valve is typically installed onto the
material inlet of the receiver and is connected to the central control system, or an accessory
control specifically designed for proportioning valve operation.
Note that a proportioning valve should never be relied upon for accurate mixing of two
materials, but are only a process convenience for loading a second material (typically
regrind). An ideal use of a proportioning valve is emptying a granulator of reground material,
in quantities known to not exceed the limitations or specifications of the process.
If requirements for the proportioning require more accuracy, consult with your supplier
regarding the use of a blender in lieu of a simple proportioning valve.
Material Outlet, connected
to receiver Inlet
10- INITIAL START UP
For optimum loader operation, adjust the load time so that the vacuum chamber is almost
completely full at the end of the load cycle. Do not allow the chamber to overfill. NOTE:
VLP series powder loaders include an extended body to house the cartridge filter(s). Loaded
material should not be allowed to be filled up into this extended hopper area. It is intended
only as a housing for the filter cartridges(s), not a hopper for collecting loaded material.
Adjust the dump time so that it is only 1 to 2 seconds longer than the time necessary to
completely empty the chamber. The number of pulses needed to clean the filter depends
upon the material being conveyed. Clean, virgin pellets require minimum filter cleaning while
very dusty regrind or powder may necessitate a maximum filter cleaning sequence. Adjust
the pulse cycle so the filter(s) remain clean. A mid range setting is suggested as a starting
point.
VL-VLP IM 19 JUNE 2017
External Proportioning Valve
Solenoid: Connection to control
and connection to compressed
air supply.
© 2017 NOVATEC, Inc. All Rights Reserved
Material #1 inlet,
Preferably
Regrind
Material #2 inlet,
Typically Virgin
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