AEC OS Series Gravimetric Batch Blenders - Manual (Page 45)

Page 44 of 118
The working pressure of the blender cylinders is 60 psi (4.14 bar). This is
adjustable by the regulator supplied on the rear panel of the blender. It is important
to prevent fluctuation in the air pressure to the blender by not installing the unit on
an airline. If this is the case, an accumulator tank with a check valve may have to
be provided by the customer to ensure the blender a steady air supply.
CAUTION!
Always disconnect the compressed air supply when working on
any part of the blender.
4-7 Blender Set-up
4-7-1 Description and Objectives
This section will discuss the mechanical setup and control system setup
of the OS/OA blending system. After reading this chapter, you should be
familiar with the mechanical setup and the electronic control setup of the
OS/OA blending system.
4-7-2 Weigh Hopper Installation (“OS” Models only)
Remove the weigh hopper from the shipping box and install it in the
blender on the load cell brackets. Connect the airline and close the
mixer door, securing the latch.
4-7-3 Load Cell Adjustment
The mechanical setup of the OS/OA blending system involves the
adjustment of the weigh hopper load cells (Please refer to the figure on
the next page). This figure illustrates the proper adjustment of the load
cell mechanical stop bolt. The setting for the positive stop is necessary
to prevent the load cell from being “over-ranged” by excessive loading
on the weigh hopper. The setting for the load cell stop is forty
thousandths of an inch maximum (.040”). A feeler thickness gauge, with
the weigh hopper empty, should be used to set this.
If a feeler gauge is not available, the weigh hopper should be filled with
the material that is to be blended, and the stop adjusted so there is just a
very small gap (a couple of sheets of notebook paper) between the load
cell, and the blender base stop. This will allow the load cell to operate
without mechanical restrictions and provide an overload safety. To adjust
the stop, adjust the screw located on the bottom of the load cell. Adjust
the screw up to increase the gap and down to decrease the gap.