Vertical FBD or fluid bed dryers are frequently used in the pharma sector for drying purposes during wet granulation.The drying is dependent on the principle that hot air fluidizes the wet product & air goes out through the outlet duct retaining the product inside the drying chamber.
To Retain the product inside the drying chamber or to prevent loss of product along with air through the return duct we always use a filter at the top of the drying chamber.
This filter is usually made of canvas cloth & known as a bag filter, finger filter, or cloth filter.
What Is Kevlar Rope?
As the name indicates Kevlar is the rope & it is the specific rope that is used to hold the Filter bag frame inside the drying chamber.
The FBD filter or pocket filter is fitted on a SS ring & this ring is hung with the help of a rope inside the drying chamber of the Fluid bed dryer, this rope is known as a Kevlar Rope.
Functions / Role Of Kevlar Rope
As we discussed previously one of the main roles of kevlar rope is to hang the filter cloth inside the drying chamber of the fluidized bed dryer.
The other main function of Kevlar rope is to act as a shaker to prevent blockage of the filter cloth.One end of the Kevlar rope is attached to the SS ring on which the filter is fitted & the other end of the rope is attached to an outside motor which produces shaking vibrations after specified time intervals to prevent clogging of finger filters & ensure uniform drying.
Properties Of Kevlar Rope
Following are some properties of a good Kevlar Rope.
- It must be made of Stainless steel.
- It must be heat resistant.
- Kevlar rope must be able to bear high temperatures because, during the drying process, it is directly exposed to the hot air so it must not melt or deshape at high temperatures.
- It must not shred particles during shaking vibrations.
- It must be flexible to withstand jerks during shaking vibrations.