Agitated Filter is a closed vessel designed to separate solid and liquid by filtration under pressure or vacuum. The closed operation ensures odorless, contamination free and nonpolluting working conditions maintaining product purity and hygiene. The advanced technology of agitation and hydraulics used in the equipment makes it versatile and user friendly. The resulting wet cake can be reslurried and washed thoroughly with water or solvents unlike in” NUTSCHE” type filters or centrifuges. Wash liquid quantity can be controlled and recycled, reducing effluent load. The discharge of wet cake is automatic. If the process demands filtration in chilled or hot condition, it is also possible. Drying of wet cake is also possible when drying features are incorporated.
The equipment is functionally safe and easy to operate. It can carry out various phase of process operations, viz: Crystallization , filtration, extraction, Discoloration, Washing and drying. The number of conventional machines employed for filtration process are also reduced. It has multi- functional utility, saves on power, labor, floor space, material wastage and time.
The filter/filter dryer has wide field of applications in chemical, pharmaceutical, Agro chemicals, fine chemicals, and food industries. Sterilizable pharma versions are available for aseptic requirements
CONSTRUCTION:
Agitated Filter is a Cylindrical, Vertical closed vessel made as per pressure vessel codes. The vessel is fitted with plane filter media, either metallic or synthetic at the lower end of the vessel. Specially designed slow speed, robust Agitator assembly is mounted on vessel. The Agitator design adopted is advanced and unique to this system .The “ S” Type self centering blades are made from heavy sections to handle liquid as well as solids. It has four movement; each movement, either single or in combination is designed to carry out specific operations.
The movements of agitator are:
1. Clock wise rotation: For smoothing cake surface and compacting it during filtration.
2. Anticlock wise rotation: F or stirring near filter media to keep it clear of sedimentation, reslurring while washing and atomized discharging.
3. Upward movements: Operated by hydraulic cylinders at constant speed to assist mixing.
4. Down ward movement: Operated by hydraulic cylinders with variable speed to assist squeezing and discharge.
OPERATION/PROCESS:
CHARGING: Slurry is charged into filter preferably by gravity flow from Reaction installed above the filter or by slurry pump.
FILTRATION: While charging the slurry into the filter, filtrate will start passing through filter cloth by gravity. To enhance filtration rate and to keep filter media clean from initial sedimentation, the agitator can be brought down most position and keep on rotating in forward direction. The cake height can be built up in successive steps.
CAKE WASHING: Wash liquids is sprayed into the chamber on cake through a spray ring. The stirrer blades are lowered to agitated the slurry to obtain good cake washing. The wash liquid is sprayed repeatedly though the filter cake by the same driving force as used during the first stage filtration.
SMOOTHING AND COMPRESSION: At the closing stage of the filtration process described above, the stirrer blades are lowered on the cake surface. The specially designed hydraulic system, takes over to perform a systematic, efficient and productive smoothing of the cracks which appear in the cake, leaving behind low residual moisture 10to 20% less as compared to other conventional filters. This results in energy saving in drying process at least by40%
FILTER CAKE DRYING: After the final wash, filtration and compression, the heating medium is fed into the limpet/jacket and the chamber below filter plate as well as Hollow shaft and Hallow Blade .The stirrer blades are lowered and the cake mass is agitated during the drying stage. The vapour can be removed under vacuum applied to the filter. Drying can be enhanced by purging a hot gas through cake.
PRODUCT DISCHARGE: The stirrer blades are rotated and lowered to cut away the upper surface off the filter cake. As the blades descend into the cake mass, the discharge value is opened and a controlled discharge of the cake is achieved.
SALIENT FEATURES:
Designed and Manufactured to suit critical hygienic conditions of pharma and food industries.(cGMP MODEL)
Detachable bottom is operated by hydraulic cylinders and held tightly with zero leakage. Offered in various materials of constructions, like stainless steel, carbon steel, rubber lined carbon steel and lead lined carbon steel.
Offered in a wide range of filtration area capacities.
Significant squeezing of filter cake is possible, there by resulting in considerably lower residual moisture in the cake, resulting in reduction in energy requirement for drying of filter cake by upto40% depending on cake characteristics.
Method of operation is totally enclosed, neat and hygienic. These conditions are excellent for solvent recovery, handling of toxic and hazardous materials without human intervention. Enables easy, non-manual and automatic cake/solid discharge. Scraper blade is provided to scrap the material which may stay on shell.
The unit is designed with minimum maintenances feature.
Hallow shaft and Hallow Blade for thorough drying.
Specially designed tank cleaning nozzle is provide for through cleaning of inside of filter body.
Hydraulic power pack: is a part is a part of system. It has multiple functions viz:
- 1. Discharge valve operation for labour – free cake removal.
- 2. Lowering and lifting the Agitator.
- 3. Lowering the detachable bottom when provided.
- 4. Driving the Agitator, when hydraulic motor is used.
The above features along with precision in manufacturing give excellent process control viz. filtering, spreading, compacting, reslurrying, washing, discharging and drying.
Filter Media: Filter media is selected as per specific process requirements. They are textile cloth from natural or synthetic fibres, metal wire clothes of multi layered sintered mesh.
Detachable Bottom: Filter/Filter dryer when supplied with detachable bottom can be lifted/lowered by hydraulic cylinders. Unique quick descending/ ascending arrangement is also available where the bottom is held in position by hydraulic cylinders during pressure filtration. This arrangement can assist in quick changing of filter cloth and product change.
Discharge Valve and Sampler: Plug Type Side Discharge valve is provided near the filter plate. Designed as per customer requirements-Metal to Metal sealing, Polymer sealing, Quick openable doors Online Product sampler with Valve.