Blastrac 1-8DECMKI, Operating Manual

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Operating Instructions 1-8DEC 230V
Description and Function
3.2 Continued
This blast wheel is enclosed in an abrasion resistant housing that is also lined with
abrasion resistant liners. These liners are located in areas where the most wear is
present. The operator can change them periodically to protect the housing. A 3
horsepower, 3600-rpm electric motor, drive the blast wheel. The motor is then
connected to a set of belts and sheaves that are in turn connected to a bearing unit.
The blast wheel is equipped with a cast in place impeller for easy maintenance. This
impeller pre-accelerates the abrasive to the wheel blades in controlled portions.
Abrasive that is gravity fed to the center of the wheel is accelerated in segments and
directed through the control cage. The control cage determines where the abrasive is
introduced onto the rotating blades of the wheel which in turn determines where the
abrasive is being “aimed”. The setting of the control cage is very important when
setting up the “blast pattern” covered in Section 5.
An analog ammeter provides readout of the current of electric motor that drives the
blast wheel. This provides a direct indication of how much abrasive is being delivered
to the wheel. This reading should not exceed the full load amperage of the motor,
which is 17 amps at 208/230 volts.
3.3 Abrasive Control Valve
Refer to Figure Number 3
The abrasive control valve regulates the amount of abrasive delivered to the blast
wheel. The main component of this device is a butterfly valve surrounded by a ring of
magnets, which, when closed, seals off the abrasive flow. A slight gap exists between
the disk on the butterfly assembly and the inner wall of the valve. When the disk is
horizontal, the magnets provide a seal that closes the gap with steel shot and stops the
flow of abrasive. The valve is manually operated with the actuator below the handle.
Do not allow this valve to open so far that the ammeter reading exceeds the full load
amperage of the motor. (17.0 Amp @ 208/230 VAC) An adjustable stop is
incorporated on the valve actuator at the handle, which allows for this adjustment.
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