Self-priming Positive Displacement
The Progressive Cavity Drum Pump meters liquid color by positive displacement. The pump consists of a single helix steel screw, called a rotor, rotating within a double helix hollow stator constructed of an elastomeric material.

The rotation of the rotor within the fixed stator causes empty pockets or voids to travel or progress upward, drawing liquid into one end and expelling it out the other end, producing a positive displacement pumping action. The double helix stator produces an overlapping of voids resulting in smooth non-pulsating pumping action. Pressures of 200 to 300 PSI are achievable.

Fits on 30 or 55 gallon drum
The pumping unit is mounted at the end of a stainless steel pipe which serve3s a double purpose. First, it positions the pumping unit at the bottom of the liquid drum totally immersed in the liquid while the controls and drive motor are positioned safely above the drum. Second, the pipe serves as a conduit in which the liquid flows up and out of the drum. A quick-release coupling joins the motor and shaft allowing for easy removal of the motor and controls from the pumping unit.

Automatic Speed Control
Because pumping rate is directly related to pump operation, accuracy is obtained by controlling the exact degree of rotation of the drive motor. The unique Maguire Digital Controller is designed to do this with precision.

A digital counter provides the means for predetermining the exact degree of rotation and, therefore, the precise amount of coloring that will occur during each cycle. When the preset count is reached, the motor automatically shuts off, ensuring that no excess colorant is metered.

Motor speed is automatically controlled by the internal microprocessor to allow color metering to occur uniformly over the entire screw return cycle. The operator need not concern himself with motor speed adjustment, voltage fluctuations or changing cycle times.

To determine the proper setting for the counter, a simple formula is used based on shot weight in grams, percent let-down desired and the liquid color weight in lb/gal or gm/l. Once production is started, the counter setting can be adjusted up or down as required to achieve the desired shade of coloring.

In addition to this precise control of the quantity of liquid being metered, the microprocessor ensures the motor speed is precisely held regardless of changing torque requirements.

Extrusion Following
With this option the drum pump follows the speed of the extruder automatically. Any changes in extruder speed are followed exactly by the pump output.

A tachometer that currently exists on your extruder provides either an AC or DC voltage output. When the "tachometer feedback" signal is fed into the Maguire Drum Pump controller, the pump output is then able to match the extruder speed up or down.