Fluid Bed Dryer Operating Procedure

Definition:-

Fluid bed dryer also named fluidized bed dryer is one of our main products. To know its working principle, first you should know what "fluidizd bed" is. A fluidized bed is formed when a quantity of a solid particulate substance (usually present in a holding vessel) is placed under appropriate conditions to cause the solid/fluid mixture to behave as a fluid. This is usually achieved by the introduction of pressurized fluid through the particulate medium. This results in the medium then having many properties and characteristics of normal fluids; such as the ability to free-flow under gravity, or to be pumped using fluid type technologies.The resulting phenomenon is called
fluidization. 

Working Principle of Fluid Bed Dryer:The powder granule in vessel (fluid bed) appears in the state of fluidization. It is preheated and mixed with clean and heated air. At the same time the solution of adhesive is sprayed into the container. It makes the particles become granulating that contains adhesive. Being of unceasing dry through hot air, the moisture in the granulating is evaporated. The process is carried out continuously. Finally it forms ideal, uniform and porous granules.

CAUTION :1. Check and certify that area and equipment are clean and suitable for starting the operation.
2. Ensure that main is in “OFF” position before dismantling FBD for loading.

A. ASSEMBLING :1. Unclamp the fixing bolts of retarding chamber and allow it to rest on the trolley. Take out trolley along with the retarding chamber.
2. Check and certify the suitability of the clean finger bag.
3. Fix the loops of the finger to the hooks of the shaker.
4. Place the bag in between the retarding chamber and fluidization chamber.
5. Clamp the retarding chamber on the body with fixing bolts.

B. OPERATION

LOADING1. Load the bowl with material to be dried.
2. Rake the product uniformly in the bowl to avoid lumps.
3. Move the product bowl below the retarding chamber keeping the window in viewing position.
4. Position the bowl.
5. Lift the bottom of the FBD by moving the jack handle to the opposite side and seal the trolley to the retarding chamber
6. Check and ensure that there is no leakage.
7. Set the timer and switch on heating and fluidization, maintaining the desired inlet air temperature.
8. Stop drying at intervals of specified in BMR and dedust the finger bag by shaking it.
9. Take out trolley and rake the granules to avoid formation of lumps.
10. Watch the fluidized flow through the Perspex windows.
11. Continue heating till required outlet air temperature is achieved. Air-dry if mentioned in BMR
12. Put off the heaters and bring the timer to zero.

UNLOADING1. After drying is complete put off the main switch
2. Shake the finger bag vigorously and dust retarding chamber.
3. Unlock and withdraw the bowl.

CLEANING OF FLUID BED DRYER 

ObjectiveTo carry out the drying operation in proper manner and to avoid the cross contamination of the granules.

Cleaning MaterialsCleaning Agent : Water
Cleaning equipment : lint free duster, nylon scrubber

Method of CleaningProcedure for Product to product change over
Clean the body of the drier and plenum with a dry clean duster. Then wipe it with a duster soaked in 0.1% teepol solution followed by a duster soaked in water.

Detach finger bag from hook by opening perplex windows in the retarding chamber

Unclamp the fixing bolts of retarding chamber & allow it to rest on the trolley. Take out trolley along with the finger bag and retarding chamber.

Remove the finger bag & bowel

Dedust the individual finger chamber of finger bag & keep it in a polythene bag. Send it for laundering
Take retarding chamber along with trolley and bowl with hot water scrubbing with clean nylon scrubber. Then wash them with 0.1% teepol solution, rinsing thoroughly with hot water followed by water. In case of sticky powder use steam

DryingWipe out the body of FBD retarding chamber, trolley & bowl by using a clean dry lint free duster. Further dry by running FBD at 70°C (without material) for 15 minutes.

AssemblingFix the laundered finger bag in a metallic hanger around the retarding chamber. Clamp the retarding chamber on the body with the fixing bolts. Lift the bottom of FBD and seal the trolley with bowl to the retarding chamber.
For Batch to Batch change over
Clean the body of the driers & plenum with dry duster
Clean the interior surface of the retarding chamber bowl with a clean dry duster
Clean the interior surface of the retarding chamber bowl, trolley.
De-dust the fingers of the finger bag.

NoteIf the cleaned FBD is not used with in 24 hours after cleaning or there are signs of dust or powder settled on FBD, then dedust the bowl retarding chamber & body by using a freshly laundered lint free duster.

Cleaning scheduleDuring every product & batch change over

Status labelReplace the “To be Cleaned” status label with “Cleaned and Ready for Use” label