Energy saver software for dryers

Software developed by Maguire Products, Inc. for its VBD™ vacuum dryer constantly monitors the changing conditions of dryer operation and automatically makes adjustments to ensure that power consumption remains the lowest of any resin dryer in the plastics industry.

 

While vacuum dryers are known for using far less energy than conventional desiccant dryers, until now their energy efficiency has been greatest when they were operated at or near their throughput capacity. Actual throughput varies, however, according to the rate that the molding or extrusion process demands. Prior to Maguire’s development of the new energy saver software, the vacuum dryer used increasingly greater amounts of energy as throughput decreased, unless the dryer was set up for the lower throughput. At throughputs that were one-tenth of capacity, for example, energy consumption could be ten times greater than at full capacity if the dryer was not set up correctly.

 

If operated at full capacity of 300 lb. (136 kg) per hour, the VBD-300 dryer typically exhibits an energy consumption of 46 watts/kg/hr when drying polycarbonate at 250 °F (121 °C). Now the same dryer can operate at nearly the same low level of energy consumption at throughputs of only 25 lb. (11 kg) per hour with no operator intervention.

 

 

“The new Maguire software eliminates the penalty for low-throughput operation by using data acquired from previous heating cycles to make adjustments to the current cycle, ensuring that the absolute minimum amount of energy is used while achieving adequate and complete heating of the resin,” said Frank Kavanagh, vice president of sales and marketing. “We now offer the software as a standard feature on all VBD dryers, and it is available for upgrading existing dryers at no cost.”

 

In addition, all controllers for VBD dryers now include a standard onboard energy consumption display and logging capability. The controller shows both real-time and time-averaged values in the industry standard of watts/kg/hr.

 

In comparison with desiccant dryers, the VBD vacuum dryer consumes 60% less energy, dries resin in one-sixth the time, and substantially reduces the heat history to which polymer is exposed. The speed with which the VBD system removes moisture makes properly dried polymer available for production only 35 minutes after a cold start.