The Maguire LPD:
A revolution in resin drying
The Maguire Low Pressure Dryer (LPD) is a revolutionary device that uses vacuum to accelerate the resin drying process. The use of vacuum provides many process and cost benefits compared to conventional drying technology.
Maguire Products did not invent the science of low pressure (vacuum) drying. In fact vacuum drying has been used in the manufacturing process of plastic resins, chemicals, food and pharmaceuticals for many years. But, Maguire Products is the first to bring this technology to the plastics industry in a package that is affordable, reliable and simple to operate.
Why is the LPD Better?
How the LPD Dryer Works:
The dryer operates with 3 Stainless Steel canisters that are mounted directly onto a carousel that indexes counterclockwise 360 degrees. Through this 3 step process each canister systematically goes through the following 3 stages to dry materials.
Filling: In the first stage the canister is filled with material using a specially designed dispense valve to ensure the canister can never overfill. Mounted above the dryer is a surge hopper for material resin which ensures the canister can be filled in the minimum amount of time necessary.
Heating: As the canister is being filled the heating process also begins. Temperature settings are made easily by simply dialing in the required temperature on the thumbwheels of the controller.
Due to the relatively small volume of the canisters when compared to traditional large drying hoppers the material can come up to the required temperature rapidly. Once the canister has been heated for the time set it will then index automatically to the next stage.
Vacuum: When the canister indexes from Stage 1, it is sealed and very strong vacuum is applied. As air pressure drops, water boils at lower temperatures. Once the material is under vacuum, the boiling point of water falls from 212ºF (100ºC) to 133ºF (56ºC). Moisture is rapidly driven from the material and evacuated to ambient air. The dryer controller continuously monitors vacuum level ensuring the vacuum remains high. If the proper level of vacuum is not maintained an alarm will sound.
Material Removal: After the Vacuum cycle is completed the canister indexes again to the material take off position. Under automatic operation a valve in the bottom of the canister is opened and material then flows from the canister into a material take off pan. Dry material is then drawn by a vacuum loader to the process machine. Material level in the takeoff pan is monitored continuously by a proximity sensor. At the end of the cycle time the canister will index back to Stage 1.
Changing Materials on the LPD Dryer
The dryer comes with an innovative and time saving Clean Mode. When this is selected as soon as the proximity sensor detects that all material has been removed from the canister or the cycle time has expired, it will notify the operator by alarm. This allows for the canister to be quickly removed, cleaned and prepared for a new material.
Canister Removal and Cleaning:
Each canister is easily removed from the central carousel by releasing two latches.
Once the canister is removed and emptied all material contact surfaces can be readily accessed for quick and simple cleaning. By turning the canister upside down operators can access the screen by rotating the retaining plate and then both the plate and the screen are removed for complete cleaning.
Surge Hopper Removal and Cleaning:
The surge hopper above the dryer is also designed to be quick and easy to remove. The lightweight hopper includes a shut-off slide gate and can be easily lifted out. The frame can then be rotated out of the way, allowing access and removal of the fill valve.
Material Take-off Pan Cleaning:
The material take off pan slides out of position for complete access and easy cleaning.
The dryer includes a filter that protects the blower from any carry-over of dust or fine particles. The filter requires cleaning periodically and this can be achieved by removal of the quick access panel on the front of the dryer.
* US voltage: 480, Europe / Asia voltage: 400
Please note the following:
*Final moisture content as recommended by the raw material manufacturer.
**Recommended cycle time is based on average initial moisture content. For high initial moisture content cycle time should be extended 5 minutes. When in doubt please contact Maguire service.
***Drying temperature as recommended by the material manufacturer.