Thursday, August 19, 2010


1 Before dismantling the equipment the electric supply must be turned off.
2. The strap retaining the filter bag unit is unclipped and the finger sleeves of the bag are detached from the holding hooks.
3. The bag is removed and taken to the washing area where the external surface of the bag is washed with hot water. The bag is turned inside-out and then washed with hot 1 water. Where material is adhering to the bags it will be necessary to scrub the surface with a detergent solution (such as Teepol) using a nylon brush.
4. After washing, the bag is placed on a hanger and allowed to dry in air.
5. The bag support frame as well as the sleeve supports are washed with hot water and the washed surfaces are then wiped with a clean, dry cloth.
6. The drier bowl should preferably be washed after every drying cycle although if the same product is being dried in lots it will be sufficient to wash at the end of the working shift. The bowl is wheeled to the washing area where it is freed from the wheel base. It is first flushed with hot water and then scrubbed, if necessary, with a nylon blush to dislodge all adhering solid material. Care should be taken while cleaning the sieve so that it is not damaged. A cleaning agent (such as Teepol) and/or a scouring powder may also be employed to facilitate cleaning. The bowl is finally rinsed with hot water in the form of a jet and then dried by wiping with a clean, dry cloth. The bow 1 is then covered with a nylon cloth or any other suitable cover and stored in a dust-free area.
7. Powder from the interior surfaces of the drier cabinet is removed by suction using vacuum. A nylon brush may be used to remove adhering powder. The surfaces are cleaned with a clean, damp cloth and then allowed to dry.
8. The air intake filter is removed and replace with a freshly cleaned filter.
9. The external surfaces of the fluid bed drier are wiped with a clean, damp cloth and then allowed to dry.
10. The drier should be switched on and the airflow adjusted according to the drying 'conditions specified for the process. It should be ensured that the material is adequately agitated and that channels are not formed in the mass of the wet material. Channel formation is normally recognized when the air outlet temperature is close to that of the air inlet temperature soon after the drying process staI1s.
11. At the end of the time cycle when the drier stops automatically, the air bags should be shaken by pulling the lever attached to the drier, in order to dislodge the fines which collect in the bags.
12. The main switch should be turned off, the bowl should be lowered and the trolley holding the bowl wheeled out. The contents of the bowl should be examined to know if any further drying is required.
13. If redrying is necessary, the material in the bowl should be stirred with a scoop and the bowl should be put back into the drier. Steps 7 to 12 should be repeated until the material complies with the relevant specifications at the stage of processing.
14. The details of drying, including the inlet and outlet air temperatures, the drying times of the cycle, the date of drying and batch details should be entered on the fluid bed drier log sheets.
If a flammable liquid, such as, alcohol, has been used in preparing the granules, such granules should be exposed in trays in an explosion proof area, before being taken up for drying in fluid bed drier.

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