FLUID BED DRYER

The “PAAN PHARMATECH ENGINEERS PVT.LTD.”

Fluid Bed Dryer has adopted new concept of GMP

Regulation with improved performance.

Ideal for drying wet granules.

The product container is lifted by externally mounted

pneumatic cylinders.

Safety features like Earth Circuit Relay, Solid flow

monitor and explosion vent for excess pressure.

AC frequency controller for the blower to control

fluidization.

Electro Pneumatic Control Panel -Complete

automation with PLC to control the full drying cycle.

Capacity 5kg – 500kg of dried product having initial

moisture content of 20 –25 %.

Optional provision of built in Raker ( slow speed

agitator) in the FBD bowl, externally driven to ensure

uniform drying of granules without slopping in the drying

process, thereby reducing the total processing time and

eliminating contamination by human touch.

The Inlet air plenum is dome safe and equipped with

drain. It is positioned above the floor to prevent the

accumulation of contaminants/bacteria underneath and

to facilitate cleaning.

The entire exhaust air filters are easily removable for

cleaning. Provision of HEPA filters in inlet air system.

DESCRIPTIONS (FEATURES)

FLUID BED GRANULATION

It is important to verify that the filter bag is also appropriate

for the product to be scaled up. Failure to use the proper

bag may result in product loss (if the openings are too

large) or unnecessarily restricted air flows (if the openings

are too small).

DIFFERENCES IN THE MOC IN FILTER BAGS

It is also very important to select proper screen to avoid

clogging of the bottom screen as this could result in slower

drying time extended well beyond predicted time.

DIFFERENCES IN BOWL SCREENS

It is more important to select the right pump type during

scale up and ignore small differences in the spray rates.

DIFFERENCES IN SOLUTION DELIVERY SYSTEMS

While using untreated air, the moisture content of the inlet

air varies according to the seasonal and weather changes

of the ambience (sunny, dry, wet, heavy rains humid

summer etc). For products having a narrow LOD limit (say

between 2-2.5%), weather variations can be problematic

while predicting the end point.

TREATED AIR V/S UNTREATED AIR(HUMIDITY CONTROL)

It is best to agree on a single formulation at the feasibility

level. Allow for changes like quantity of granulating

solutions and for variations in lubrication levels within

acceptable range. Increase in fines may require one to

increase the lubrication.

FORMULATION CONSIDERATION

Do not change the ancillary equipment throughout the

scale up process to minimize variations.

ANCILLARY EQUIPMENT

The unit operation:

All these cycle have common parameters

such as Fluidization air volume, inlet and outlet air

temperatures and filter bag shaking cycles. All three

operations must be understood and controlled to get the

optimum results.

The Premixing Cycle, Spray Cycle

and Dry Cycle.

MAJOR PROCESS PARAMETERS DURINGSCALE UP

This serves the purposes of both mixing the components

as well as preheating prior to the spray cycle. It is not

required to use a very high air volume at this stage, in fact,

that can lead to de-mixing due to the micro fined

component getting more trapped in the filter bags and the

coarser particles remaining in the bowl. Many equipment

today has built in safety interlocks that will prevent start of

the spray cycle before the premix is over and the required

temperature is achieved. Mixing Cycle for 45kg to 500kg -

3 or less components 1 to 2 mins and for 3 or more

components 3 to 5 mins

THE PREMIXING CYCLE

ltr/min using a multi headed nozzle.Spray rates ml/min -

45kg (150 to 350), 120kg (500 to 2000), 300kg (2000 to

3000), 500kg (3000 to 6500).

Generally 35-40 deg.C for organic and 60-70 deg.C for

water based product are useful at starting for the spray

cycle to begin.

The general rule is that there are dampers on both the inlet

and outlet sides. The inlet side is kept 100 % open and the

control is exercised on the outlet damper. The aim is to lift

the powder with maximum exposure to the spray zone.

INLET TEMPERATURE SET POINT:

DAMPER SETTINGS:

THE BAG SHAKING CYCLES :

Bag shaking duration:

The bag shaking cycle should be set as per the conditions

present during the cycle. Larger equipment may have

multiple settings for airflow during the drying cycle.

Granules are heaviest after the spray cycle and will

require maximum fluidization air. As the moisture is

driven off, the bed lightens and less fluidizing air is needed

to sustain particle flow. Therefore varying levels of air is

required throughout. Thus the bag shaking frequency will

increase during the whole process. Magnehelic gauges

provided as a useful tool to decide bag shaking frequency.

By tracking the time/pressure relationship, it is possible to

optimize the bag shaking cycles. It is a critical factor to

obtain the shortest possible drying cycle.

In a Spraying Cycle 15 to 45sec

and in Drying Cycle 20 to 120sec.

NOZZLE SELECTION AND HEIGHT:

ATOMIZING AIR:

SPRAY RATE:

Up to 100 kg batch sizes a single nozzle is used. Beyond

this multi headed nozzle is common. The nozzle height is

a vital. It depends upon the type of the product, the type of

operation (granulation, agglomeration, particle coating

etc.), and the amount of atomising air used.

The atomizing air pressure varies from about 2 bar to 4

bar. This will however depend upon the kind of binder

used its viscosity and its evaporation rate.

Spray rate varies as the bowl charge increases. 100kg to

300 kg, it is normally safe to use spray rates of around 2-3

THE SPRAY CYCLE

INLET AIR TEMPERATURE

SET POINT :

The inlet set point for the

drying varies between 80-95

deg.C for water based and

50-60 deg.C for solvent

g r a n u l a t i o n s . F o r

t empera tu re sens i t i ve

product drying the highest

allowable as a guideline.

Damper settings begin with

full open at both ends to

gradual closing of outlet

dampers to almost be equal

to the setting at the end of the

spray cycle

THE DRY CYCLE

TECHNICAL SPECIFICATION

MODEL - KgFBC / FBG

Top SprayWorking Volume Ltr.

Wurster Design Ltr./ Size

Steam Consumption @ 3 kg / hr

0Temperature C

Exhaust Fan kw

Elec. Heating kw

5

22

6 (7”)

12

35

100

7.5

15

45

18

48

100

7.5

30

110

24

70

100

7.5

60

220

36

140

100

18.5

450

-

210

100

18.5

670

-

280

100

30

1020

-

380

100

45

120 200 300

14 (9”)

38 (12”)

14 (9”)

38 (12”)

102 (18”)

38 (12”)

102 (18”)

102 (18”)

170 (24”)

417(32”)

170 (24”)

417(32”)

417(32”)

820(46”)

820(46”)

AHU:

3Air Volume m / hr 750 1000 1500 3000 4500 6000 8000

Top Spray

3Atomizing Air m /hr

Wurster Spray

25 25 30 110 110 110 110

25 90 90 270 270 540 540

25 25 2 x 25 2 x 25 4 x 25 - -

Off.: Plot-36, Shramsafalya, RSC -11, Veer Savarkar Nagar, Thane (W) – 400606 Maharashtra (INDIA).

Tel.: 91- 22 – 2582 8524, 0250-6454728/29 Telefax: 91 – 22 -2583 3896

Website: Email: paanfabriworkengineers@yahoo.inwww.paanpharmatech.com

Pharmatech Engineers Pvt. Ltd.PAAN

Pharmatech Engineers Pvt. Ltd.PAAN

'Fluidisation' is a process in which a bed of small solid

particles is suspended and agitated by a stream of air, Fluid

Bed technology has found enhanced use in

pharmaceuticals for drying, granulation, palletizing and

coating.

DESCRIPTION

FLUID BED PROCESSOR

Innovations in technology area, emerged more versatile,

automation and validation, in the Fluid Bed Processors

and the Rapid Mixing & Granulator. But The future will

witness the use of FBP with its feature like automation,

validation, closed and 'Single Pot Technology'

benefits, in wet granulation and particle coating.

SPRAY GRANULATION &PARTICLE COATING

It has two different geometry and this can effect the granulation

quality. Top spray granulator (FBE Granulator-Fig.2) in which a spray

nozzle introduced through the cylindrical expansion zone. In other

version, the nozzle introduced through conical expansion zone

(Fig.1) to allow higher fluidization. This results in lesser filter clogging

as against cylindrical expansion zone (due to uniform velocity).

TOP SPRAY MODE

THE EFFECT OF SPRAY MODEAND CHAMBER GEOMETRY

BOTTOM SPRAY (WURSTER) MODE

In wurster mode a cylindrical partition is placed slightly above the

bottom in the product container. The spray nozzle sprays the solution

through this partition onto the particles. The design of the air distribution

plate allows more air to pass through the partition than in the area

surrounding the partition. The fluidized particle moves through the

centre, meets the spray and travels upwards and then due to velocity

reduction falls back outside the partition.

FLOW PATTERN OF WURSTER COATING

MULTIPROCESSOR (TOP SPRAY & WURSTAR DESIGN)

It is observed that F.B.G. (spray granulation), often

results in granules with low bulk densities when

compared with granules made from wet mixed and dried

process methods.

Pharma experts found that, at the start of the spraying

process, a droplet of the spray solution is hit by the dry

air as it leaves the spray nozzle.Although each

individual droplet is small, the overall surface area

exposed to the dry air from a stream of droplet is so large

that instantaneous surface evaporation of the solvent is

great.As water/solvent evaporates, thus the rise in

viscosity is also great and the stickiness increases.

This results in “Case Hardening”. The skin of the spray

droplet becomes thick preventing further evaporation

and the inside of the droplet remains wet. Migration of

the inner wetness is limited due to the case hardened

situation.

Binder does not migrate from the spray droplet into the

powder particle, so does not penetrate to particle space

for the resultant densification during drying. The

enveloping of the spray droplets with powder and other

particles isolates it from the incoming air stream like

insulation and in combination with the case hardening

effect, retards the ability to dry the older spray droplets.

This favours the evaporation of further spray droplets, to

a case hardened state.

The solution as prescribed by experts is to humidify

the incoming air in an energy efficient manner by

creating a loop of the circulating fluidizing air. When

the hot and humid exhaust air is re-circulated back

in to the process, normal fluidization could be

maintained without excessive drying. The high

humidity of the inlet air stream retards premature

surface drying of the spray droplets enabling the

binder droplets to remain thin enough for

penetration in to the powder particles. The

resultant granules are seen to be very dense and

spherical. It can also be assumed that by controlling

the proportion of the humid air, it will be possible to

achieve the required bulk density and flow

characteristics of the product.

FLUID BED DRYER (FOR R&D)

TECHNICAL SPECIFICATION

MODEL

Container Volume(Ltr.)

Batch Capacity

oDrying Temp in C

Steam Consume @2

3 kg/cm in Kcal/hr

BLOWER

Capacity M³/hr.

Elec. Motor HP

Electric Loadin KW

FBD-30

110

30

18

12925

2500

5

FBD-60

215

60

36

25850

4000

10

FBD-120

430

120

50-85

54

51700

6300

15

FBD-200

650

200

-

82720

8000

20

750

250

-

103400

10000

25

850

300

-

129250

12500

30

1500

500

-

196460

16500

25+25

FBD-250

FBD-300

FBD-500

(FIG.1)

(FIG.2)

FLUID BED GRANULATION

Scale ups occur generally at 50 kg, 100 kg and 300kg

levels. Both technical and non technical issues frequently

affect scale up progression decisions. Thus successful

scale up may very well depend upon factors.

PRACTICAL & TECHNICAL FACTORSOFTEN ENCOUNTERED SCALE UP: