Conair
The new MicroWheel dryers from Conair deliver the efficiency and precision of desiccant-wheel drying in a compact configuration that can be mounted on the feed throat of a moulding machine or extruder.
Thought to be the smallest wheel dryers available, they offer an alternative to compressed-air dryers and small twin-tower units, making them an ideal choice for medical processors and others running small quantities of expensive engineering resins.
Jamie Jamison, Conair Drying Product Manager, said: "When it was introduced nearly 10 years ago, the Conair Carousel Plus wheel dryer was revolutionary in its ability to hold rock-steady temperatures and dewpoints, while reducing energy consumption, speeding start-up and reducing maintenance requirements. However, even the smallest units were too big for machine mounting and had fairly large throughput minimums, so processors had no alternative but to use other, less efficient drying technologies."
The new small Conair dryers are offered in two basic models: the MW1 and the MW2. Because they use brushless blowers with speed control built in, the dryer can be easily programmed to deliver exactly the right amount of process airflow to dry the different resin volumes. Each model is available with several different hopper capacities. The MW1 units can support hoppers of 0.2-cu-ft (5.7-l), 0.5-cu-ft (14.2-l) and 1.0-cu-ft (28.5-l) capacity. Including the hopper, they range in height from only 495 mm to 704 mm and the largest weighs just 48 kg.
The larger MW2 dryer is available with 1.0-cu-ft (28.5-l) and 1.5-cu-ft (42.5-l) hoppers. The heights of MW2 units are 704mm and 978mm. The weight of the largest unit is 65kg. Thus, these small dryers are ideal for machine mounting.
The speed-controlled blower, along with a highly-intelligent control, makes it possible to fine-tune drying parameters to achieve perfectly dried material with a minimum of energy input and little chance of over- or under-drying. The control comes pre-programmed with 30 different recipes for various resins. The user simply identifies the material being dried along with the expected throughput and the control automatically adjusts temperature and airflow to match resin-supplier guidelines for effective drying. In addition, there is storage space for 20 user-defined recipes, which can be variations on the preset recipes or entirely new programs created by the processor.
Other standard control features include:
- Material Protection Management (MPM) system, which automatically reduces process air temperatures when return-air temperatures exceed setpoint. This is usually an indication that throughput rate has dropped and that material is not being withdrawn from the drying hopper as fast as anticipated. This standard temperature setback feature saves energy and prevents over-drying.
- Real-Time Energy Consumption Monitoring, which tracks the dryer’s power consumption, allowing users to fine-tune energy use while maintaining proper drying conditions. Factoring in electric rates, processors can calculate how much power is needed to produce a given quantity of parts
The MicroWheel dryers are usually priced lower than compressed-air dryers (while offering significantly greater feature content) and are comparable in price to twin-tower dryers, while being simpler to operate and maintain. The Conair dryers require only 220v single-phase power and absolutely no compressed air is needed. An air-to-air heat exchanger on the return air circuit means that no water drop is needed for the aftercooler.
Standard stainless-steel hopper liners are fully insulated, with a protective aluminum outer shell. A stainless-steel machine-throat adapter, with resin-discharge port and purging compound input bypass port, is available optionally.
