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Fluidized Bed Wurster Coater Equipment

We are manufacturers of FBD Wurster Spray Coating Equipment Machine complete Machine in SS316. Complete machine with air filter, heat exchanger, product container, filter, blower, compressor Instrumentation & PLC and the working platform is offered on turn-key basis. Our buyers staff will be trained on our working machine. The offer will not be vague with many extras as every thing will be included.

Fludized Bed Wurster Coating Equipment Wurster Coater being fitted.
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Wurster spray coater is essentially a taller version of fluidized bed drier. Plant scale wurster machine is about 5meters (17 feet) tall and it needs about 6.5meters (22feet) clear space from the ground. A Wurster equipment can be easily used as a fluidised bed drier by removing the spray nozzle and the partition in the product container. The bottom plate needs only minor modification. It can be used as a top spray granulation and coating machine by retrofitting a top spray nozzle. You can have both the units i.e. top-spray and bottom-spray to begin with by just adding a top-spray nozzle to it.

The complete assembly consists of an Air handling unit followed by a Heat Exchanger. Filtered air is heated and it enters the wurster tower. The product particles are fluidized in the tower and coated by spraying an emulsion or any other coating liquid from the bottom. After fluidization, the exhaust air passes through a an expansion chamber and then a filter system. Air for fluidization is sucked by a blower which is attached to the top exit of the tower. A cyclone separator and/or scrubber may be required for better control of air pollution. Standard parts include a peristaltic pump for emulsion or liquid spraying, mixing tank for coating liquid, an Air compressor, a dry air unit for instruments and filter cleaning and instrumentation for automatic operation. Our offer also includes supporting structures and the platform. Safety flap is fitted at two places; one on the top dish and the other on the shell.

Air Handling Unit: It consists of a filter followed by a heater.
Filter: A pre-filter of say 20 microns, followed by a final filter of 5 microns is used. For a very strict air quality requirement, a HEPA filter may be used. Use of finer filter will increase the blower load.
Heater: For large size wurster machines, Shell & Tube type heat exchanger, fitted with continuous tension wound crimpled fin tubes is used. Heating is done by steam or by thermic-fluid. The same result can be obtained by Electric heaters.
This AHU consisting of air-filter and heater, is outside the main system and generally made of MS. However, we recommend that SS304 or SS316 may be used.

Main Tower: A plant size machine requires not less than 5 meters (17 feet) height. It consists of a jacking system followed by product container fitted with a wurster spray nozzle, expansion chamber and filter unit.
Product Container: The product container is trolley mounted generally a conical vessel with a wire-mesh at the bottom placed on a specially perforated bottom plate. This bottom plate is designed for wurster action and you may check the wurster bottom plate fixing methods. For a plant size equipment conventional bottom plate is best suited. In the center of the product container, there is a coating partition that has an arrangement to adjust the gap from the bottom. This adjustment can be done from outside the container. A sight glass and light glass are fitted at the bottom to observe the performance of fludization and wurster action. A sampling port is provided. Two such containers are offered with each machine to ensure minimum down town in loading and unloading a batch.
Spray Nozzle: A specially designed wurster spray nozzle enters the bottom plate. The nozzle is easily removable and it gives a fine spray for the most desirable coating.
Expansion chamber: Ample space is provided above the product container for the fluidised material to remain suspended after the spray. This allows time for the sprayed material to coalesce and dry on the particles. The conical portion of the expansion chamber reduces the speed of the upward moving particles. It enters the straight portion and starts settling down in a circular movement.
Filter: In fluidized beds, filter generally consists of finger type bags that are shaken by pneumatic movement. This filter system is a poorer cousin of cage type filters that are shaken by reverse purge of compressed air. The pneumatically shaken finger filters are cheaper and easily available ex-stock by specifying the number of fingers. Almost all the filter cloth vendors will be able to offer it. They do not need compressed air and save you money on buying a compressor for fludized bed dryer. In case of wurster coating equipment, the compressed air is needed for the spray and it need not be bought extra. The reverse purging of compressed air in cage filters is a great idea and all the knowledgeable vendors are switching to it. In a plant scale machine, the cages are divided in to 4 parts and each part is cyclically shaken for 5 seconds, every 2 minutes.
Blower: Blower is generally kept on the mezzanine or it may be placed some distance away. Blower being an outside item, it is often made of MS. Some people may prefer to have the fan made of SS304 and body-casing of MS coated with FRP inside and Epoxy paint outside. We recommend that, all the body-casing and the fan be made of SS316. The attached motor and bearing etc are not available in SS316 and it may be fitted as per availability.
Compressor: A compressor is needed for spraying and for the filter purging.
Dry Air Unit: Provided for Air purging and instrumentation.
Mixing Tank: Emulsion storage & Mixing Tank for a batch size is included.
Peristaltic Pump: GMP model is included.
Structure: Support structure, ladder and mezzanine is included.
Instrumentation & Controls: The main instruments and controls consist of:
1. Venturi Flow meter to measure the air flow rate and control it. A PLC based Venturi meter is used for the same. A Variable Frequency Drive VFD is used to control the speed of the motor to give a constant desired flow rate.
2. Compressed Air is used to Shake Filter Cloth with 5 seconds per 2 minutes. Auto Control of 4-Alternate Section every 30 seconds. Solenoid valves may be used for cyclic purge of bags.
3. Temperature Indicator with alarm set at __C is used monitor temperature of the inlet air and of the product container. Exit air temperature is also measured. PLC can be set to shut-off the system against any parameter that is sensitive.
4. Pressure indicators are used to measure the pressure of spray atomizing air and of shut-off needle.
Please check our sale purchase offer for wurster coating machine for a complete system including structure ladder and mezzanine, AHU with filter & Heater, Main Wurster Tower, Compressor, Dry Air Unit, Blower, Instruments, PLC Controls and eight days hands down training for two people of buyers company in our running plant.

FBD Wurster Coating Equipment Lay-out
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Please send your enquiry to ajk@wurstercoating.com.

Wurster Coating Company
Ankleshwar Gujarat  and Mumbai Maharashtra, India.
Every thing about Wurster Coating Process Parameters, Principle and Scale up will be covered here.
We offer encapsulated chemicals.

1-may-22