AEC OS Series Gravimetric Batch Blenders - Manual (Page 20)

Page 19 of 118
1-12-5 Weigh Hopper Discharge Valve
The weigh hopper discharge valve holds the material until it is dumped
into the mixing section. The cylinder is actuated by a solenoid in the
valve stack on the rear of the blender.
In looking at the pneumatic circuit, you can see that the air regulator
controls the flow of air to the valve stack. When the weigh hopper
discharge cylinder solenoid valve is not electrically energized, it will
provide air pressure to the air cylinder and hold the shaft in an
extended position, holding the dump valve closed.
When the air cylinder is actuated, the air pressure to the dump valve
will be removed, causing it to open.
The air cylinder on the weigh hopper includes a spring return to allow
the cylinder to retract in the absence of air pressure on the cylinder.
This will cause the dump valve to open.
CAUTION! The pneumatic system used on the OS/OA, like all pneumatic
systems, is highly sensitive to dirty, wet or contaminated air. If
dirt, water, or any other air-borne contaminates enter the system,
the components could be damaged and injury to the operator
could result. A proper air supply must be supplied to the blender.
When the safety circuit is disabled, the air pressure to the cylinder will
drop off by shutting off all the air supply to the valve stack with the pilot
operated master air valve. This will also cause the weigh hopper
discharge door to open.