Sterling SDA 1000-5100 Manual Do Utilizador

Large Dehumidifying Dryers  

Maintenance 

45 

Symptoms of Worn Out Desiccant 
The moisture adsorption capacity of the desiccant used in Large Dehumidifying Dryers 
degrades after an indefinite period of time. Useful life depends on variables such as material 
moisture content, plasticizer vapors in the return air and number of regeneration cycles.  

Your dryer may need new desiccant if it exhibits any of the following symptoms: 

•  The plastic material is not being dried sufficiently (high scrap/reject rate). 
•  The air temperature at the top of the regenerating desiccant bed rapidly climbs to 

350°F or more shortly after the start of regeneration, even though a saturated bed has 
just started heating.  

•  The process air dewpoint, measured with a portable dewpoint monitor, is higher than   

-10°F throughout the process drying cycle. 

•  Smoke or dust is being blown out of the process air outlet. 
•  Noticeable amounts of desiccant in the beds is a medium-brown color, or darker. 

If any of these signs are noticed, the desiccant in the desiccant beds should be replaced. 
Desiccant replacement kits are available from the Parts Department. If you wish, the 
desiccant beds can be repacked at your site by a service technician. 

 

•  Do not get in eyes.  
•  Avoid prolonged contact with skin.  
•  Use with adequate ventilation.  
•  Wash thoroughly after handling.  

 

Replacing the Desiccant  
Follow the procedure below to change the desiccant.  See Figure 17 below for desiccant 
tower components. 

1.  Disconnect electrical power to the dryer. 
2.  Remove the bolts and nuts securing the covers of each desiccant canister. Remove 

the covers and set them aside. 

3.  With a shop vacuum that has a 4 micron HEPA filter, carefully remove all desiccant 

from each tower. 

4.  Inspect all screens for tears or burn-through spots. 
5.  Fill each canister with 13X, 8 x 12 bead desiccant.