Raleigh, N.C.-based Aeroglide Corp.'s web site, www.aeroglide.com, provides a checklist of factors that affect purchase decisions of rotary, conveyor and tower dryers. Analyzing the differences among dryers will help you buy a dryer that will serve your process for up to 20 years or more. Examine differences in design, construction, size, features, fuel usage, output capacity and price.
For rotary dryers look at:
- Output capacity, which includes drum size, air volume, fan size, time, and temperature and control methods.
- Design durability and prospects for trouble-free operation, such as construction materials, gauge of material, flight design, drive horsepower, lubrication systems and hardness of wear components.
- Process efficiency, including power consumption, seal method between fixed and moving components, fan design and type of filter system.
For tower dryers, consider:
- Output capacity, such as holding capacity, time, temperature, airflow and cooling.
- Uniformity, including retention time, airflow, air direction and product mixing.
- Potential for trouble-free operation, such as construction, fines collection, fans and heat source.
- Efficiency, which covers construction, heat source and recirculated air.
For conveyor dryers, check:
- Output capacity such as bed size, holding capacity, time, temperature, airflow and cooling.
- Product uniformity, including retention time, airflow, air direction, product mixing and number of passes required.
- Prospects for trouble-free operation, such as durability of construction and subassemblies, including dryer frame, roll chain, bedplates, fans and panels.
- Access for maintenance and sanitation procedures, which include inner and outer access doors and panels, clearances inside the dryer, fines removal and minimal ledges.