Sterlco SGBD Series Batch Gravimetric Blenders - Manual (Page 18)

Bulletin Number Chapter 2: Functional Description 18 of 101
Figure 6: Typical Slide Gate Assembly
Each of the diamond gate air cylinders is actuated by a solenoid valve, which are controlled
by the blender controller.
When the solenoid valve is energized, it opens the metering valve cylinder. When the
solenoid valve is de-energized, it closes the metering valve cylinder.
If the power is interrupted to the blender, the metering valves will return to the closed
position, to prevent material from over-filling the weigh hopper/mix chamber.
Weigh Hopper
The weigh hopper on the Slide Gate/Auger blender is used to weigh each batch of material,
and includes an air-operated discharge valve. After the batch is weighed and the level sensor
in the lower mix section is uncovered, the valve will open and discharge the batch into the
mixer with the existing blended material. The discharge valve is also provided with a quick
disconnect so the weigh hopper can be removed for cleaning.
On a Slide Gate blender, the weigh hopper rests on each side on a precision cantilever load
cell. To remove the weigh hopper, lift the hopper from the bottom, hold the dump door
closed, and slide it out once clear of the locating tab on the bracket above the load cell.
Once the hopper has been cleaned, reposition it onto the load cell brackets, using care not to
damage the load cells. Position the hopper as close to the center position between the load
cells as possible.
Note: If the blender is in metering mode with one of the slide gates open, do
not open the front door of the blender!
Note: The safety switch shuts off the air supply to the blender. An open feeder
slide gate stays open, and an overflow of the weigh hopper can occur!
Note: Use care when replacing the weigh hopper, since the load cells are
delicate weighing instruments and can be easily damaged. Do not use
force to push in the weigh hopper. If it is positioned properly, it will slide
in very easily.
Note: Load cells, if damaged, will have to be sent back to the manufacturer for
testing and evaluation.