Sterling 060 Manuale Utente

Continuous Loss-in-Weight Blenders Chapter 2:  Functional Description 

15 

hoppers are not controlled nor read by the blender.  Their existence is solely for the use of a 
low level alarm to be wired into a separate controller.  These would not be present on a 
standard blender. 

The hoppers may be equipped with a polycarbonate sight glass.  This is mounted in the upper 
cone section of the hopper.  This is useful for a quick reference of the material level in each 
hopper. 

The supply/re-fill hoppers should be vented to the atmosphere through the louver located on 
the lid of each hopper.  This louver is required to prevent the loading system from creating a 
vacuum in the hopper, which would prevent material from flowing out properly.  This 
situation could be caused by a leaking discharge seal on the vacuum receiver. 

Each ingredient weigh hopper assembly consists of a conical mass flow weigh hopper, a 
precision load cell and a discharge tube disc seal.  A mass flow weigh hopper is a steep 
degree conical hopper with vertical side walls with a discharge tube on the bottom.  Each 
weigh hopper is sized to the blender ingredient metering requirements.  This assembly is 
responsible for weighing the material ingredients as they are metered out by the metering 
auger assemblies located below each weigh hopper.  The manufacturer believes this is the 
best way to weigh free flowing pelletized materials.  This design allows the hopper to weigh 
only the material and nothing else, unlike other systems that weigh the heavy auger 
assemblies.  This design eliminates extra variables, such as auger drive vibrations, etc. from 
the weighing system and increases the load cell resolution.  Each weigh hopper will be 
refilled periodically as material reaches the preprogrammed low weight setpoint for that 
hopper.  Clear hopper side walls or sight glasses are provided on each on the weigh hoppers 
to allow the operator to monitor the levels.