Project KEL

FABRICATION AND DESIGN OF VIBRO-FLUIDISED BED DRYERS
Industrial Project Report
SUBMITTED TO
National Institute Of Food Technology Entrepreneurship And Management
Kundli, Haryana
For The Partial Fulfilment of Requirements of Program
Master of Technology (FPEM)
In The Department of FOOD ENGINEERING
SUBMITTED BY
SAQIB GULZAR (212014)
SUJOSH NANDI (212016)
Under Supervision Of
Faculty Guide
DR. P K NEMA
ER. VINKELARORA
Organization Guide
MR P K ARORA
MR TUSHAR CHURY

Introduction
Kilburn Engineering Ltd. is a Williamson Magor Enterprise. Williamson Magor has interested in tea, batteries
and engineering with a turnover of US$ 500 million.
The other companies in the group are:
1. Eveready Industries India Ltd.
2. McNally Bharat Engineering Ltd.
3. Mcleod Russel India Ltd.
Kilburn has over 30 years of successful track record in manufacturing world class critically customized process
equipment and completing projects on schedule. Kilburn customers both international and domestic, include
large companies in several industries namely chemical, petrochemical, oil, gas, refinery, fertilizer, nuclear
power plant and food processing industries covering tea, sugar, paddy and coconut.
Products & Services
Kilburn is an ISO 9001-2008 and ASME ‘U’ stamp certified technology led company, specialized in process
design, engineering, manufacturing, project management and installation of equipment and systems for various
process plants. The company is a leader in solid, liquid, gas drying systems and specially designed skid
mounted packages for offshore platforms. Kilburn has systems engineering capabilities with a multi-
disciplinary approach and has a highly qualified and talented pool of engineers in mechanical, chemical,
metallurgical, aeronautical, electronics/ instrumentation and electrical engineering disciplines. Apart from the
process equipment/ systems, the company also undertakes execution of EPC contracts.
EPC contracts
Kilburn undertakes execution of various systems on turnkey basis for projects in diverse Industries namely
Chemicals, Heavy Chemicals & fertilizers, Petrochemicals & Refineries, Nuclear Power Plants offsite systems,
Onshore oil/gas exploration & Gas based power plant etc.
It has successfully completed several such projects covering Detailed Engineering, Shop/ Site fabrication,

Erection & Commissioning involving Process, Mechanical, Electrical, and Instrumentation & Civil activities.
Few projects completed are Caustic Evaporation, Concentration, Prilling & Flaking Plants (5 Projects), Soda
Ash Calciners (4 projects), E-PVC spray Drying system, Rotary Dryers & Coating/ Granulation System,
Storage/ Mixing Silos or PVC Plant, Various Solid Drying/ Adsorption.
Facility Overview
Area of Plot : Total 30960 sq meters
Covered manufacturing area : 13,450 meters
Office space : 2850 sq meters
Installed Power : 1350 KVA with full back up
Maximum lifting capacity- 100 Tons
Plant and Machinery
A. Metal Cutting & Forming
 Presses
 CNC Press Brake 250 MT Capacity
 Hydraulic press 300 MT capacity x 4 M span
 Hydraulic press 150 MT capacity x 4 M span
 Shears
 Shearing Machine (3 M x 13 mm thick.)
 Hydraulic NC Shearing Machine (3 M x 15 mm thick.)
 Bending Machines
 Plate Bending Machine 25 mm x 2.5 M
 Plate Bending Machine 16 mm x 1.5 M
 Welding Machines
 Submerge Arc Welding machine with column
 SMAW & Boom, MIG, TIG
 Radiography Enclosure
 Cutting Machines
 CNC plasma cutting machine
 Pug Cutting Machine for different thickness
 Portable keyway cutting machine

 Portable edge preparation machine
 Manual Plasma Cutting Machine 100 thick
 Other Metal Forming Machines
 Electronic Torque Control Tube Expander
 Nibbling Machine
 Automatic Bevelling Machine
B. Machining
 Drilling Machines
 Radial Drilling Machine RM 65 - 3 Nos.
 Radial Drilling Machine 1·
 Pillar Drilling Machine
 Magnetic Portable Drilling Machine
 Lathes
 CNC Multiple tooling long Lathe HMT make
 Heavy Duty Long Lathe 7M long
 Kirloskar Lathe 3M long
 Medium Size lathe 2M HMT make- 3 Nos.
 Shaping Machine
 1 M x 0.5 M - 2 Nos.
 UNIVERSAL MILLING MACHINE 50 Diameter
 Spindle x 1.5 long
 BFW make Universal-1 No.
C. Material Handling Equipment
 EOT Crane 50 MT - 1 No.
 EOT Crane 25 MT - 3 Nos.
 Mobile Crane 8 MT-3 Nos.
D. Others
 Balancing Equipment
 Dynamic Balancing Machine FIE Make
 Painting
 Compressed Air Gun

 Controlled Humidity Chamber
 Utilities
 Pneumatic Compressor for Pneumatic Grinding & Chipping
 Diesel Generator 750 KVA -1 No.
 Diesel Generator 125 KVA - 1 No
Inspection & Testing Facilities
Efficient in-house quality control systems and associated with several leading reputed third party inspection
agencies
 Major Inspection and Testing Facilities
 Non Destructive Testing facility
 Destructive Test facility
 Test run set up
 Dynamic Balancing facility
 Hardness Testing facilities
 Decibel Level and Vibration Meter
 Special Instruments
 Electrometer for Paint thickness measurement
 Surface Comparator
Manufacturing Facilities
Kilburn’s manufacturing facilities are located near Mumbai, well connected by highways and ports, facilitating
transportation of large sized equipment within India and Overseas.
Kilburn manufactures equipment in materials such as Carbon steel, Stainless Steel, Inconel, Hastelloy, Monel,
Nickel and Duplex Stainless Steel.
Location:
Plot No. 6, MlDC Industrial Area, Kalyan Bhiwandi Road, Saravali, Thane-421311, Maharashtra, India
Machine Shop:

a) 133M long x 23 metres wide
b) 10 T EOT Crane
c) 8M under hook height
Light Bay:
a) 133M long x 23 metres wide
b) 30T EOT Crane
Medium Bay:
a) 133M long x 25 meters wide
b) 50T EOT Crane
Heavy Bay:
a) 133M long x 25 meters wide
b) 100 T EOT Crane
R & D
Kilburn is a government approved R&D house. The company’s strength lies in its successful assimilation of the
world class technologies. The company attaches highest priority to its R&D activities on a counting basis. Its
R&D centre has developed new equipment of international standard for its certain end user industries.
Quality Control and Management Systems
Efficient in house quality control systems and associated with several leading and reputed
third party inspection agencies

 Asme 'U' Stamp Authorised Shop
 Iso 9001: 2008 Certified Company
 Registered With National Board Of Boiler & Pressure Vessel Inspectors
 Ce Marking
 Ped Certification
Collaborates/ Technical Associates
Kilburn has ongoing technical collaborations and case to case tie ups with
 Nara Machinery Co. Ltd., Japan
 Carrier Vibrating Equipment, Inc., USA
 EmDE Industrie- Technik, Germany
 Bertrams Limited, Switzerland
 Nova-Synergy Industrial Solutions (NOVARGI), Spain
 Technicas Reunidas, Spain
Solid Drying Systems :
 Rotary Dryers, Calciners, Kilns & Coolers.
 Fluid Bed Dryers & Coolers.
 Flash Dryers.
 Paddle Dryers & Coolers.
 Spray Dryers.
 Band Dryers.
 Vibratory Fluid Dryers & Coolers.
Adsorption System:
 Air/ Gas/ Liquid Drying Systems.
 Solvent / Vapour Recovery Systems.
 Catalytic Purification Systems.
Oil Field Systems:
 Instrument Utility Gas Drying Systems.
 Fuel Gas Conditioning Systems.
 Customised Skid Mounted Packages.

 Gas Sweetening Packages.
Air Handling Systems:
 Industrial Centrifugal Fans.
Fabricated Equipment:
 Pressure Vessels & columns.
 Heat Exchangers.
 Special Equipment to Customer design.
Office & Other Buildings:
3500 m2 for Design, Engineering, R & D, Pilot Plant, Manufacturing, Marketing, Commercial & Finance
Departments, HR & IR Dept. Canteen & Power House, etc.
Design & Engineering Facilities
Following design & engineering facilities are available
 Latest Autocad Edition 2011
 PV Elite Software for mechanical design of vessel
 3D Autocad Inventor software for equipment modelling.
 MRP System for material tracking.
 ERP
Various Types of Materials Processed
 Duplex Stainless Steel
 Incolony 825
 Incolony 800
 Hastalloy
 Monel
 Inconel 600
 Aluminium
 Nickel
 Stainless Steel(All Grades)
 Carbon Steel(All Grades)

Inspection & Testing Facilities
Following inspection & Testing Facilities are available at ours Works:
 Pressure and Vacuum Test-Pneumatic and Hydraulic
 NDT: Radiography, Dye Penetration Testing, Magnetic Particle Examination, Ultrasonic Examination.
 Dark Room Facility.
 Destructive Test - Physical, Chemical, Corrosion Test, Micro, Macro, etc.
 Precision Measuring Instruments such as Verniers, Micrometers, Bore Gauges, Dial Indicators,
Hardness Tester, etc.
 Qualified Welding Procedures and welding operators for various Exotic materials.
 Measurements of noise, vibrations, flow and temperature.
 Mechanical Run-test of Rotary equipments.
 Performance testing of Blowers on test bed.
 Testing Instruments.
List of Engineering Consultants, Inspection Agencies & EPC / LSTK Contractors
We are on the approved vendor list of following Engineering Consultants 1 Contractors for our entire range
of products:
 Engineers lndia Limited
 Aker Solutions Ltd.
 Jacobs Engineering lndia Pvt. Ltd.
 Technimont ICB Pvt. Ltd.
 Uhde lndia Ltd.
 Lurgi lndia Co. Pvt. Ltd.
 John Brown Technologies lndia Pvt. Ltd.
 Chemtex Engineering lndia Ltd.
 Toyo Engineering Ltd.
 Technip KT lndia Ltd.
 Mott MacDonald Consultants lndia Pvt. Ltd.
 Tata Consulting Engineers Ltd.
 Saipem lndia Projects Ltd.
 IBI Chematur Engineering Ltd.
 Lloyds Registrar of Shipping

 Development Consultant Pvt. Ltd.
 Projects & Development (India) Ltd.
 Larsen & Toubro Ltd.
 Hindustan Dorr-Oliver Ltd.
 McNally Bharat Engineering Co. Ltd.
 Hyundai Heavy lndustries Co. Ltd.
 Samsung Engineering lndia Pvt. Ltd.
 KBK Chem Engineering Pvt. Ltd.
 Tata Projects Ltd.
 Essar Constructions lndia Ltd.
 Indian Oil Tanking Ltd.
 Korea Heavy lndustries Corporation
 National Petroleum Construction, Company
 Sarku Engineering Services Ltd.
List of some of the Important Customers (Domestic)
 Oil & Natural Gas Corporation Ltd.
 Gujarat Narmada Valley Fertilizers Co. Ltd.
 Gujarat State Fertilizers & Chemicals
 Reliance Industries Ltd.
 Larson & Turbo Ltd.
 Nuclear Power Corpn. of India
 Chemplast Sanmar Limited
 Brooke Bond Ltd.
 Hindustan Unilever Ltd.
 Nirma Limited
 Cochin Refinery Limited
 Hindustan Petroleum Corpn. Ltd.
 Jindal Praxair Oxygen Co., Limited
 Essar Constructions India Limited
 United Phosphorus Limited
 Philips Carbon Black Ltd.
 Hi-Tech Carbon Black Ltd.

 Deepak Fertilizer & Petrochemicals Ltd.
 GHCL Ltd.
 Tata Chemicals Ltd.
 First Carbon Technologies Pvt. Ltd.
 Essar Offshore Subsea Ltd.
List of some of the Important Customers (Export)
 Samsung Heavy Industries, Korea
 Korea Heavy Industries, Korea
 Formosa Plastics, Taiwan
 Cabot Corporation, France & USA
 Thai Carbon Black Co., Thailand
 Komline Sanderson, USA
 Columbian Chemicals, Brazil, Canada & Germany
 Mitsubishi Heavy Inds. Limited
 National Petroleum Construction Co., Abu Dhabi
 Sarku Engineering Services SDN BHD, Malaysia
 Bertrams Chemical Plants Limited, Switzerland
 SABIC – Saudi Arabia
 Petrofac International Limited, Malaysia
 Lamprell Energy Ltd., Abu Dhabi
 Swiber Offshore Construction Pte. Ltd., Thailand
paddle Dryer
In the realm of paddle dryer, Kilburn introduces a unique cunieform paddle geometry in collaboration with
Nara Machinery, Japan which leads to substantial reduction in the size of continuous conduction dryer.
Principle of operation

Heat transfer from heating medium to the material is by conduction. Efficient drying of
powdery/crystralline/granular material is achieved by bringing it in direct contact with revolving cunieform
hollow paddles, without using any gas as heating madium.
The trough is uniformly heated by passing heating medium through the jacket. This ensures that the entire
material in the dryer is in full contact with the total heat transfer area during its passage through the dryer.
Compact and Sturdy Design
More than 75% of the heat transfer area is compacted in the paddles, which are closely and alternatively
arranged at fixed distances on each hallow revolving shaft. The heat transfer area per unit volume of the dryer is
very large thus reducing the size of the dryer. The space requirement and the civil costs for erection of the dryer
are considerably reduced. The dryer is constructed from thick plates and heavy shafts giving it an inherent
sturdiness.
High Thermal Efficiency
Te revolving paddles alternately and sectionally compass the material at the slanting surface of the paddles, and
expand the material at the cavities behind the paddles. This keeps the material in a constant state of agitation
resulting in very high heat transfer coefficient with consequent reduction in equipment size.
Self-Cleaning Paddles
The combined movement of the slanting surfaces of the revolving paddles and material generates dispersion
forces which automatically clean layers that are liable to stick to the paddles.

Uniform Drying
The intimate mixing action of paddles results in uniformity of temperature at any cross section. The movement
of the material in the dryer is in plug-flow pattern. This enables uniform drying of the material.
Experiment measurement of residence time by using coloured chips
Thermal Processing
Steam, Hot water or oil can be used as heating medium. Drying, calcining, Roasting, Sterilizing, Cooling,
Crytalizing and Solvent recovery can be carried out by using different heat transfer media. By partitioing the
shaft and jacket, two different heating media can be incorporated in the same equipment. This feature facilitates
two temperature drying, drying-cum-cooling, drying-cum-roasting.

Minimal Dusting
The paddle Dryer is totally enclosed and the entire heat transfer is achieved by conduction. Only a small
quantity of hot air is used to scanvenge evaporated moisture thus preventing condensation. This results in
minimal dusting and reduces or eliminates dust collection equipments. Heat loss through exhaust air is also
substantially reduced.
Suitability For All Types of Powders
The number of thermal shafts, the speed of revolving paddle sets, and the temperature of heating medium can
be selected to suit the individual drying characteristics of the material. Dust free operation enables efficient
drying of dusty powders.
The geometry of the paddles and the casing is such that the material is homogenously mixed with no stagnant
pockets.

Material of Construction
The paddle Dryer can be made of any weldable material of construction. For abrasive materials, the wear parts
can be hard faced or stellited.
W-Type(2 Shafts)
T-Type(4 Shafts)

Component of Paddy Dryer
In the fabrication of paddy dryers, the first step is the understanding of General assembly drawing also called as
GA drawing. In GA drawing all the components of the drying system are shown as per the process flow. There
are separate drawings for all the components.
1. Control Gear for F D Fan
2. F D Fan (Along with duct)
3. Feed Hopper for FBD
4. Fluidised Bed Dryer
5. Exhaust hood for FBD
6. Air heating system for FBD
7. Discharge system for FBD
8. Air Heating System for VFBD
9. Control Gear for Hot Air Blower
10. ISO piping for Steam Heater for FBD
11. Feed Hopper for VFBD
12. Hot Air Blower (Along with duct)
13. Flexible Bellow Assembly
14. Flexible bellow Assembly between Feed Hopper and Discharge of FBD
15. Vibro Fluid Bed Dryer (VFBD)
16. Exhaust System for VFBD
17. Discharge system (Chute)
Paddy is dried in 2 phases, first in Fluid Bed Dryer where the moisture content of the parboiled paddy drops
from 37% to 24% and in the second phase in Vibro Fluid Dryer the paddy achieves its final Moisture content
of 13 to 14% as per the storage requirement.

FBD is installed to reduce the moisture load on the VFBD and to increase the capacity of the dryer.
The fabrication of the paddy dryer starts with the fabrication of individual components. First the critical
components are fabricated, followed by the fabrication of non-critical components to have maximum time for
any rectification in the critical component.
Usually the fabrication starts with the main frame on which the Plenum Chamber and Drying Chamber rests.
The Main frame is a framework of channels and Angles made of MS. Followed by the Main frame the
fabrication of Plenum chamber takes place. Plenum Chamber is the component used for supplying air inside the
drying chamber. It is made in 2 parts which are joined by nut bolts by providing flanges, reason being the large
size of plenum chamber which hampers in its transportation. There are 2 Plenum Chambers in Paddy dryer; first
one for the FBD and other is for VFBD.
Upon the plenum chamber rests the Perforated Stainless Steel sheets on which the material is dried. These
sheets come in the length of 2.5m x 1.2m.
Drying Chamber for FBD is different than that of VFBD. FBD drying chamber is made of MS and has a
trapezoid shape. It is also supplied with side window for inspection.
For FBD the hot air is supplied by using a FD fan which has a motor of capacity 40 HP
Plenum Chamber of VFBD is similar in function as that of FBD but is structurally different in size and shape.
Above the Plenum Chamber is placed Drying chamber which is nothing but the SS sheets formed into a
chamber like structure. In VFBD four Perforated Sheets are used. These Sheets have circular openings of dia.
2mm.
Plenum Chambers are made by MS sheets. For Strength and providing insulation, it is made in double layers of
inner and outer sheet with channels welded and insulation placed in between.
Hot air is blown into feed side of VFBD by a Hot Air Blower (HAB). It has a 100 HP motor which receives the
hot air from the Heater and blows it into the Plenum Chamber. Plenum chamber has 3 divisions to blow air in
different zones of the Drying Chamber. Air Flow rate through the Plenum chamber is controlled by providing
Dampers at its inlet.
Plenum chamber for FBD has 6 dampers while as there is a single damper for VFBD. Besides the dampers,
there are control gears installed between Heater and HAB to regulate the amount of air into HAB. Insulation of
Glass Wool is provided to decrease heat losses in Plenum Chamber, HAB and also in FD Fan.

The Feed hopper of the VFBD and discharge duct of FBD has Flexible Bellow in between them. This Bellow is
made up of Teflon sandwiched in a rectangular frame. This bellow is provided to avoid the transmittance of the
vibrations from VFBD to static feed hopper.
Above the drying chamber is placed the Exhaust hood which has an Axial fan to remove off the moisture and
hot air from the Dryer. Axial fan has a motor of 7.5 HP capacities.
VFBD has an excitation system which provides vibratory motion to the dryer. The excitation system is placed
at the base of the dryer attached with the Plenum chamber. It is motor driven with a 10 HP motor and an
eccentric shaft connected to the link and Shaft of motor to give vibratory action.
Springs are provided on the sides of plenum chamber connected to the main frame to provide shock resistance
caused by vibrational motion.
Paddy is removed off by a discharge chute made of SS which is of the shape of a traditional winnower.
Specification of Paddy Dryer
Perforated Sheet
Triangular Pitch(P): 5 mm
Circular hole (φ) :2mm
Material :SS430
Size :14g (2mm) x1.25m x2.5m
Number of Sheet : 9
Opening :15%
Motor
For FD Fan
Material of Construction: TEFC squirrel cage induction type
Ampeire 415 ± 5% 50 Hz 3Phase AC Supply with IP55 Protection,

Insulation : Class F 40OC amb temp, Standard Shaft length
Operating Temperature: 300 c
Shaft Power : 40 hp
Motor Speed 1465 rpm
Blower Speed : 35000 m3/hr
Operating Pressure : 150 mm of WC
For HAB
415 ± 5% 50 Hz 3Phase AC Supply with IP55 Protection,
Shaft Power : 100 HP
Motor Speed : 1480 rpm
Operating Speed : 1237 rpm
Exhaust Fan
415 ± 5% 50 Hz 3Phase AC Supply with IP55 Protection
Shaft Power : 7.5 HP

Operating Speed : 1237 rpm
Excitation System
Exhaust Fan (1 No.) 7.5 HP x1000rpm Imax amp Direct Drive: Motor to be mounted on seperarate
Support
MOC: Shell CS 19g min thk
Impeller: Aluminium Cast
Pulley
HABPulley(M) : 280 PCD x4CX ø75 Bore
Iddler Pulley : 335PCD x4CX ø75 Bore
Spare Pulley : 200PCD x 4C x ø70 Bore
Steam Air Heater
Mass flow :93000Kg/hr
Operating Temperature : (30-120)OC
Heat Load: 2500000 Kcal/hr
Steam Flow Rate : 4840 Kg/hr @ 3 bag(g)
Tube: CS(A106 Gr B- Seamless) 20 NB Sch 10 pipe with extruded type Al fins, Fin OD 57± 1 mm 9-10
fins/inch
No. of Modules: 2;
No. of rows per module: 4 Nos;
Total No of tubes: 4 x47+ 4X 48 = 380

Surface Area =1620 m2
Face Area: 2880 mm(L) x2880 mm(W)
Overall Dimension: 3030 mm(L) x3030mm(H) x1225mm(W)
Inlet Outlet Connections: 100 NB / 50 NB x150# SORF Flange
Design Basis: 15 TPH feed EL 3 TPH 8OC/90%RH to 120OC Heat Load 25 LKcal/hr
Steam Fitting
40 NB CI Ball Float Trap Model-FT14-10, BSPT(F) 2 Nos.
40 NB Y Strainer BSPT(F) 2 Nos.
40 NB CI Disc Check Valve DCV3 ASA150# Flange 2 Nos.
Gate Valves -A216 GR. WCB, PTFE, ASA150# Flange
100 NB - 2 Nos. 40 NB - 4 Nos.

Tea Dryer
Kilburn Engineering Ltd. plays significant role in Tea sector in India their world class Vibro-fluid bed dryer
since 1979. By using Government of India approved research and development centre, pilot plant has been
established in tea garden which facilitates drying and testing procedure at the tea gardens only to ensure quality
in terms of flavour, taste and aroma properties, under different drying temperature, humidity and residence
time. Fluidisation and drying characteristics of CTC and orthodox teas were studied under various sets of
parameters. After their continue research, they draw conclusions that 1) Wet tea is difficult to fluidise only with
air. 2) Wet tea can be fluidized with combination of vibration and air velocity. 3) Uniform fluidisation is must
for better heat and mass transfer to improve quality of made tea. 4) Tea must be dried at controlled rate.
Fabrication of Tea Dryer
There are four models in Tea dryer based on the capacity viz. MM, DD, EE, FF, GG; with GG being the largest
in size and MM the smallest.
The fabrication process is similar to that of KPD with a few changes. There is no FBD in tea dryer for initial
moisture removal as the total moisture content to be removed is less than that of KPD.
In the Tea Dryer, plenum chamber is almost same as Paddy Dryer in shape with a perforated sheet and drying
chamber but difference lies in the opening of the perforated sheet. Here the perforations are oblong shaped.

There are three zones in the drying chamber to which the air is supplied from three different section of the
plenum chamber. In addition, a cold air blower is used in tea dryers to control the temperature. This cold air is
supplied along with the hot air which mixes in the mixing chamber installed at the mouth of the plenum
chamber.
For EE model, hot air blower with the motor capacities of 20 to 25 HP and for CAB 3 HP motor is used.
Also to provide uniform loading of feed into the drying chamber, feeding system with the motor capacity of 1
HP is installed.
The exhaust system of KTD is entirely different to that of KPD. The exhaust assembly comprises of two
DUSTRACTORS. A dustractor has a cuboidal shape with 6-8 cone shaped chimneys which are placed above
the drying chamber to remove off the moisture and the exhaust gases from the dryer. The dustractor has an axial
fan with a 5 HP motor.
At the discharge end of the Dryer there is a twin cyclone separator to retain some of the tea particulates which
are removed in the exhaust system.
Description of Main Components
Hot Air Blower
Hot air blower which is used to deliver hot air into plenum chamber is placed followed by heating assembly
with a 100 HP capacity motor. HAB, consists of centrifugal fan, has two inlet ports which sucks air at
80000m3/hr.
Plenum Chamber
Plenum Chamber, made of Mild Steel, is used for supplying air inside the drying chamber. It is made in 2 parts
which are joined by nut bolts by providing flanges, reason being the large size of plenum chamber which
hampers in its transportation. Excitation system is attached below the plenum chamber facilitates vibration. A
motor of 5 HP is attached with excitation system by an eccentric shaft.
Plenum chamber has 3 divisions to blow air in different zones of the Drying Chamber. Air Flow rate through
the Plenum chamber is controlled by providing Dampers at its inlet.

Plenum chamber is made of two sheets, inner sheet and outer sheet. Inner sheet is 2mm thick while depending
on the capacity and length of dryers, outer sheet thickness varies from 3-5 mm. Flanges, which are used to
attach two part of chamber; thickness varies from 6-8 mm.
Drying Chamber
Upon the plenum chamber rests the Perforated Stainless Steel sheets on which the material is dried is known as
Drying Chamber. In drying chamber, tea is dried in contact with hot air. Drying chamber is made of 3mm
thickness of 8 SS sheets.
Perforated Sheet
It is placed between plenum chamber and drying chamber to control the air flow rate into drying chamber. SS-
304 with 2mm thickness is used to make perforated sheet. By attaching 3 sheets of 2 meters length using
tungsten welding perforated sheet is made. The opening varies 2.5-4% according to capacity of dryers.
Dustractor
Exhaust system of tea dryer is consisted of two dustractors which help to depart hot air from drying chamber by
separating tea from hot air. A dustractor has a cuboidal shape with 6-8 cone shaped chimneys. The bottom
portion of chimneys which are placed inside drying chamber, have lot of wings help to create swirl motion of
air. It has axial fan attached with 5 HP motor.
Mixing Chamber
Mixing chamber is installed at the mouth of plenum chamber to mix hot air along with cold air coming through
cold air blower. It is divided into two portions by a square perforated section with triangular projection.
Heating Assembly
Heating assembly comprises of two things. First one is Heat Exchanger and another one is control gear which
controls the air flow rate.
Cyclone Assembly
At end of drying chamber cyclone blower is installed to remove the air from drying chamber which is
connected with cyclones. From the cyclone, after separation of tea air goes to air heater through Hot Air
Regeneration Duct and tea is collected. Specification of Cyclone
Air Flow Rate : 12000m3/hr

Operating Pressure : 80mm WC
Operating Temperature : 800C
Feed Hopper
A rotating rod comprises with impellers is attached with feed hopper to control feed rate. Rotating rod is
controlled by a 1HP motor.
Bellow
Bellow is placed between mixing chamber and inlet port of plenum chamber which deter vibration to transmit
into heating system. Below is made of two square connected with a Teflon cloth.
Excitation System
Excitation is installed at the bottom of the plenum chamber. Eccentric shaft which produces vibration has ------
eccentricity. Eccentric shaft is mounted with 3 HP motor.
Designand Development of Commercial Model
First they came in the commercial market with Phase -1 (Model A1) Vibro-fluid bed dryer which was very
simple in construction and operation. It consisted of two separate large cyclone connected with one last
discharge chute. However rest of the two chutes were open which enhanced the losses. After that Phase-I
(Model-A2) were launched which equipped with one cyclone connected with all three discharge chutes.

VFBD Phase II Dryer was compact than Phase-I. Dustractors were introduced in this phase.
In Phase-III, the refiring system was introduced with each discharge chute minimizing losses and placed the
cyclone blower at top of the end of drying chamber.

In phase-IV Dryer, centrifugal fan with axial dust extractor and removable impeller were introduced.
Multilouver damper in mixing chamber which was another modification in Phase-IV dryer, improved the
mixing of hot and cold air and also controlled the rate of air flow into plenum chamber.

In Phase-V dryer, again construction of dustractors were changed and axial flow fan with centrifugal dust
extractor were used instead of centrifugal fan with axial dust extractor.
With continues R & D works on energy consumption, operational convenience and tea quality, Field data
analysation and based on customer’s review, Phase-VI dryer has been launched in market.
Major changes in VFBD Phase – VI Model
1) Modification in mixing chamber for better mixing of hot and cold air (with lower resistance).
2) Increase in drying chamber height to avoid any side fly off.
3) Change in the design of deflector plates.
4) Increase in dryer area by modifying the design of distribution plate.

5) Dust extractor system now use axial flow fans with axial flow dust extraction for handling larger
capacity of exhaust air.
6) Modification in plenum chamber design to reduce air flow resistance.
7) Modification in exhaust system for lower resistance. Relocation of motor to vertical on dust extractors
with aerodynamic design to handle flow.

ADVANTAGES OF KILBURN VFBD PHASE VI
1) Dust Extractor changed for ease of maintenance & for more uniform air flow. Increase in output by 8%
- 10% thereby reducing the fuel consumption.
2) Cold air blower connected to the stationary section for uniform mixing of hot and cold air in Mixing
Chamber.
3) Newly designed Cold Air Mixing Chamber to ensure better mixing of hot & cold air, resulting in
improved quality of made tea.
4) Better Quality of Teas because of More uniform & better mixing of hot & cold air in mixing chamber.
5) More efficient axial type Dust Extractor System resulting in practically eliminating the carry over of
fines.
6) Motor mounting position of Dust Extractor changed for ease of maintenance & for more uniform air
flow.
7) Stainless construction of parts prone to corrosion in contact with tea.

8) Double inlet – double width Hot Air Fan for more uniform flow ( resulting into further improvement in
Quality of Teas)
9) Reduced maintenance.
10) Flexibility of use for CTC and / or Orthodox teas.
Reduction in Power
Upgradation of Various Model
Drying of CTC Tea

TECHNICAL SPECIFICATION FOR CTC TEA DRYER
Capacity Chart for CTC Tea Dryer

Drying of Orthodox Tea
To handle Orthodox Grade (Leafy), unique system was developed using vibration, mechanical mixers and air
velocity to ensure suspended bed with fluidisation which helps in uniform drying of tea resulting in improved
quality of tea produced.
Technical Specifications for Orthodox Tea Dryer

Capacity Chart for Orthodox Tea Dryer
Withering of Green Tea Leaf
Introduction
Withering influences to a great extent in the process of black tea production. It is necessary to regulate this
process to get consistent desired quality of final made black tea.
In the process of withering there are chemical as well as physical changes in green tea leaf. Total process of
wither is dependent on atmospheric condition and therefore can not be controlled which lead to affect the final
quality of made tea.
To ensure uniform quality with consistent parameters during holding of green leaf without any loss of moisture
for chemical wither and later with reduction in moisture during physical withering will improve the quality.
There is considerable saving in labour cost as well as reduction in space requirement.
System Description
 After plucking and transportation of green leaf to factory, fresh leaf is fed into double deck vibratory
feeder / screen for removal of any foreign material from green leaf.
 Green leaf is conveyed through belt conveyors to holding bins for chemical withering process.
 Holding bins have reversible belt conveyor and distributor drum for uniform spreading of green leaf
over the entire length of holding bins.
 Fine mist of water spray is also added to ensure relative humidity in the bin will be in the range of 98 –
100%. Leaf should not release any moisture during holding time. System will have provision to purge
saturated air to take away heat generated due to friction between green tea leaf layers.
 Green leaf is removed by the movement of mesh type conveyor holding / supporting green leaf and
special vertical discharge feeder using circular pipe to lift green leaf and taken out the incline guides
between pipes.

 Holding time during chemical wither will be approx. 4 hours.
 Green leaf is conveyed through belt conveyor into physical withering 3 – tier mesh type conveyor.
 For physical withering, system used axial flow fan to push hot air over the conveyor for removal of
moisture.
 System include steam heater for heating of atmospheric air to required level Temperature of hot air will
be controlled using control valve in steam line.
 For uniform distribution of air, distribution plate will be provided for the entire length of conveyorised
system.
 As the system has three tier conveyorised system to carry leaf, sealing is incorporated to avoid short
circuiting of air between conveyors.
 Residence time during physical wither will be approx. two hours with 150 – 180 mm bed height of tea
leaf over the conveyor.
Process Flow Sheet for Continuous Withering System
Technical Parameters & Equipment Sizing

Design of the FBD used for Radiator design based on the following parameter:
1. Production rate of the Plant (C)
2. Feed rate of the Plant (F)
3. Inlet moisture content (wb)
4. Product moisture content (wb)
5. Inlet temperature of the Material (TM1)
6. Material to be heated upto for drying (TM2)
7. Outlet temperature of the material (TM3)
8. Ambient Air Temperature (TAM)
9. Bulk density of the Material (BKD)
10. Specific Heat of the Material (CPS)
11. Hot air inlet temperature (Tg1)
12. Ambient air humidity (H1)
13. Wet bulb temperature of hot air inlet temperature (Tw)
14. Latent heat of evaporation at Tw (λ)
15. Average Particle Size
Design Calculation
In calculation part following parameters is taken into consideration and calculated accordingly:
1. Moisture Load

Here we calculate the amount of moisture removed from Moisture content in the feed and moisture
content from the outlet product and also we are able to know the feed rate of the material.
2. Drying Air Outlet Temperature
Here we first calculated LMTD .
Temp. Difference in the cold side T1d = Tg1- TW
Temperature Difference in the Hot side T2d = Tg1 - TM2
As the temperature of the steam is constant throughout the dryer and the temperature of outlet
material is near about the wet bulb temperature of hot inlet air, so for calculate the temperature
difference of cold side we use Tg1 and Tw.
𝐿𝑀𝑇𝐷 =
(𝑇1𝑑 − 𝑇2𝑑)
[log(
𝑇1𝑑
𝑇2𝑑
)]
Exhaust Drying Air outlet Temperature (Tgd) = Tg1 – LMTD
3. Energy Balance- Drying
Energy required to heat dry solid (Q1) = DS × CPS × (TM2- TM1)
Energy required to heat water from TM1 to TW (Q2) = W1 × 1 × (TW – TM1)
Energy required to vapourise water (Q3) = W × λ
Energy required to heat remaining water from TW to TM2 (Q4)= W2×1×(TM2-TW)
Energy required to heat water vapour from Tw to Tgd (Q5) = W ×0.45× (Tgd – TW)
Heat Required= Q1+ Q2 +Q3+ Q4+ Q5= Qd
Assuming Heat loss 10% , Heat Required (QTd) = Q × 1.1
4. Drying Air flow rate
Mass flow rate of drying air = 𝑄 𝑇𝑑/[0.24 × (𝑇𝑔1 − 𝑇𝑔𝑑 )]
5. Air Heater
Energy required to heat drying air= Mgd× 0.24×(Tg1 - TAM)
6. Dryer surface area(Vd) =
22.4 ×[(1/29)+(H1/18)]× [(273+15.5)/273]
Volume of drying air at exhaust temp (Vd) = Mgd x vd
Then we assume Fluidisation velocity as 1.65m/s
Dryer area required Ad = Vd/(vd x 3600)
7. Drying Air Fan Capacity

Mass flow rate of drying air (Mgd)
Inlet temp of drying air to the fan (Tgl)
Sp. volume of drying air (Vad)
Air flow rate (Mgd x Vad)
Static Pressure across drying fan (ΔP)
Power required to drive the fan = 2.72x10-5 x Vad x ΔP/10
Motor Rating (Assuming 75% efficiency)
8. Cooling air outlet Temp
Temp difference of hot side T3c
Temp difference of cold side T4c
LMTD (T3c-T4c)/[ln (T3c/T4c)]
Exhaust cooling air outlet temp Tgc
9. Energy Balance- Cooling
Energy to be removed to cool dry air Q6 = Ds x Cps x (TM2-TM3)
Energy to be removed to cool moisture Q7 = W2 x 1 x (TM2-TM3)
Heat to be removed (Assuming 10% extra) QTc = (Q6 + Q7)x 1.1
10. Cooling air flow rate
Total energy to be removed QTc
Mass flow rate of cooling air = QTc/[0.24 x (Tgc-TAM)]
Flow rate of cooling air (Assuming 10% extra) Mgc = 1.1 x QTc
11. Cooling surface area
Sp. volume of cooling air at exhaust temp.(vc)

Volume of cooling air at exhaust temp (Vc) = Mgc x vc
Assume velocity v1c = 1.5 m/s
Cooling Area required Ac = Vc/(v1c x 3600)
12. Cooling air fan capacity
Mass flow rate of cooling air Mgc
Sp. Volume of cooling air vac = 22.4 ×[(1/29)+(H1/18)]× [(273+TAM)/273]
Cooling air flow rate Mgc x vac
Assuming 10% extra Vac
Static Pressure across drying fan (ΔP)
Power required to drive the fan = 2.72x10-5 x Vac x ΔP/10
Motor Rating (Assuming efficiency of fan at 75%)
Paddy Dryer for Rice Mill
(Patent applied for)
Kilburn Continuous Paddy Drying System:
What is Parboiling?
Drying Principle Parboiling is “par”-tially “boiling”. It is a Hydrothermal process involving water and heat
(steam) resulting in the gelatinization of the starchy kernel without disturbing the shape and form of the paddy.
Parboiling conventionally is “Presteam-Soak-Drain-Cook-Dry” process. Cleaned and conditioned paddy is
subjected to dry saturated steam followed by soaking for a desired time-temperature. The water is then drained
and the paddy is steamed to gelatinize the starch.
Paddy after parboiling contains around 35-40% wb moisture. For safe storage it has to be reduced to around 12-
13% wb. Properly dried parboiled paddy would give minimum breakage.
There are three drying periods which will occur consecutively in time:
Preheating period: When wet grain is exposed to hot air, all the heat provided in the drying air is used to heat up the grain
to the drying temperature.

Constant-rate period: Once the grain is at the drying temperature, water starts evaporating from the surface of the grain
and the drying rate is constant with time. All the heat from the drying air is used to evaporate the surface moisture.
Falling-rate period: As the time passes,the surface remains no wet. It takes more time for internal moisture to appear at
the surface,drying rate declines and some of the heat from the drying air heats up the grain. The transition from constant
to falling rate occurs at around 18% wb moisture and is called the critical moisture content (Ms)
Kilburn Drying Concept
The rice grain is susceptible to cracking only below critical moisture where if the drying rate is too fast it becomes a
serious source of grain damage and cracking. Moisture evaporates only from the surface; so the moisture from the inner
layer first diffuses to the surface and only then it evaporates. This process therefore sets up a steep moisture gradient in
the grain, as the surface being excessively dry and the core still wet, results in moisture stress and the grain releases the
stress by cracking. Kilburn has devised a system to properly dry the grain to the desired moisture by way of gentle
handling.
The recommended combination for Drying Parboiled Paddy is : Kilburn VFBD + Column Dryer
Advantages:
 Reduction in drying cycle time of the combination system compared to conventional Column Dryers thereby
increasing the production.
 VFBD when used as a pre-dryer increases the production per column dryer.
 VFBD conveys by means of mechanical vibration and the air which ensures “gentle handling” of the paddy.
 VFBD dries paddy partially resulting in increased flow-ability. Thus paddy handling becomes easier.
 VFBD though a continuous dryer can be used as a pre-dryer to column dryer(s). The latter can operate either in
batch or in continuous mode.
 VFBD + Column Dryer combination drying process can be mapped to optimise number of parboiling tanks.
 VFBD comes with a robust modular steam air-heater with optional flash recovery system for efficient utilization
of steam.
 VFBD Paddy contact surface is made of stainless steel to ensure longevity of the dryer.
 Longevity of Column Dryer increases as it handles low moisture paddy.

Capacity
Kilburn offers capacities from 5 to 15 Tons/hr @ 36-38% wb feed to VFBD (Corresponding weight of the dry paddy
would be 3.5 Ton/hr and 11Ton/hr respectively @ 13% wb, but exact capacity would depend on the Moisture content,
Inlet hot air temperature and crop type)
Higher capacities can be obtained by installing parallel units.
Overall plant capacity would depend upon size, drying cooling and unloading time of Column Dryer.

Fluidisation Techniques are gaining increasing importance for unit operations involving drying, cooling,
calcinations and reaction engineering in Chemical, Petrochemical, Fertiliser, Pharmaceutical, Foods and other
industries.
KILBURN ENGINEERING LTD. has acquired in-depth technology, expertise and experience in this by
technical collaboration with M/s NARA MACHINERY CO. LTD., Japan

Kilburn Engg. is in position to offer advanced and sophisticated designs for thermally efficient operations
ADVANTAGES
Fluidised Bed Techniques offer following advantages
 Intimate contact of hot air and solids result in high heat transfer co-efficient. This makes the drying
system compact.
 Higher operating temperatures possible because of rapid heat and mass transfer rates.
 No overheating of heat sensitive products because of special constructional features.
 Lower capital costs.
 Easy handling of feed and product.
 No moving parts, stabilised operation and negligible maintenance.
FLUIDISATION
Fluid means a liquid. A substance is said to be fluidised when it starts behaving like a liquid. When a
determined quantity of air is passed below a perforated bed, carrying the substance to be dried, say PVC, the
material starts bubbling and it behaves like a fluid. Much depends upon the substance, its moisture content, size
of perforations, and air flow. When the air velocity is low, the bed of solids remains still. As the air velocity
increases, the particles on the upper part of the static bed begin to move and separate from each other.
When the air velocity is further increased, the particles begin to float. The particulate bed is expanded and the
movement of particles become an active formation of a mixture of air and particles. This gas-solid mixture is
called ‘Fluidised Bed’.
When the air velocity through the fluidised bed is increased further, the particles bubble more and more
vigorously, and some of the particles begin to gradually fly-off. When the air velocity exceeds the terminal
velocity of the particles, all of the particles may be blown-off resulting in ‘Carry Over’.
FLUIDISATION VELOCITY
The onset of fluidisation occurs when the drag force of the upward moving gas equals or is more than the
weight of the particles. Voids, particle geometry and particle size distribution play an important role in pressure

drop and fluidisation velocity. As seen from Pressure Drop (P) vs Air Velocity (V) graph, the fluidisation
velocity increases without any appreciable change in pressure drop.
Fluidisation velocity is best determined by pilot plant experiments on representative sample of product. This
data can be cross examined with empirical and other computerised data. Practical experience can determine the
values for commercial size plants. Improperly fluidised beds not only adversely affect the heat and mass
transfer rates but may also affect the product quality. Figures show as to how slugging and channelling affect
the pressure drop-velocity relationship.
The flow rate of heat transfer media varies from minimum fluidisation velocity (Vmf) to the terminal velocity
(Vt), which causes pneumatic transport of solids because of entrainment. For this reason, fluidisation velocity
(Vf) is kept between Vmf and Vt. The ratio of terminal velocity to minimum fluidisation (Vt/Vo) varies from
10 to 90. Smaller the particle size, lower is the ratio. Thus the practical value of fluidisation velocity is
determined by particle size distribution, shape, density and similar other considerations.
DRYING CHARACTERISTICS OF PARTICLES ON A FLUIDISED BED
The Drying characteristic of a product is displayed by plotting moisture and temperature over time. The Drying
characteristics of a product depends on its physical properties. These are identified by conducting drying tests at
the Test Centre in a small sized fluid bed dryer.
As free or surface moisture is evaporated, the drying rate remains constant. A transition or critical point is
reached when the drying rate starts falling, till equilibrium moisture is reached. The drying time is determined
by constant-rate drying, moisture content at the critical point and the falling-rate drying.
FLUID BED SYSTEM
Fluidised Bed Technique is most effectively utilised in a number of heat and mass transfer applications like:
 DRYING
 COOLING
 CALCINATION/ ROASTING
 CARBONISATION

 REACTION
 STERLISATION
BASIC COMPONENTS
Following are the basic components of a Fluid Bed System.
1. Distributor Plate.
2. Plenum Chamber.
3. Drying Chamber.
4. Hot Air System.
5. Feed System.
6. Dust Collection System.
7. Product Discharge System.
A typical Fluid Bed Dryer is schematically shown here……….
FOUR VITAL ELEMENTS OF A FLUID BED SYSTEM
REGULATED FEED SYSTEM:
A fluid Bed System requires an inbuilt feeding mechanism which will ensure a regulated feed, and also alter the
feed rate as and when desired. There may be a number of occasions when product moisture variation needs to
be controlled by regulating the feed rate.
MECAHINCAL SCATTERER:
While handling wet feed having higher moisture content, it is desirable to spread the wet feed over as large area
as possible. The wet feed which is not initially fluidised, starts fluidising after losing its moisture partially by
coming in contact with material already in the fluid bed. The mechanical scatterer acts as a de-lumper and
distributes the material uniformly across the bed.
DISTRIBUTOR PLATES:

Quality of fluidisation is very sensitive to the design of Air Distributor. A properly designed Distributor ensures
requisite size of bubble formation and gas solid contact. This ensures uniformity of heat and mass transfer.
Configuration of Distributor Plate is selected based upon particle size, fall through, other material
characteristics, and operational requirements, such as change of grades, cleanability etc.
PRODUCT DISCHARGE SYSTEM:
An overflow and underflow product discharge system is found extremely useful. This controls the height of the
fluid bed and handles agglomerates effectively.
BATCH TYPE CONTINUOUS FLUID BED DRYER
It comprises of a cylindrical or square vessel fitted with a distributor plate. The fluid bed plate can be rotated
90°. Hot air is supplied from below through a conical vessel. Wet material is fed from the top and dried product
is discharged downward by rotating the plate.
Such a system allows continuous feed and discharge.
SALIENT FEATURES:
1. Accurate control of retention time and uniform drying.
2. High co-efficient of heat transfer.
3. Simple operation.
4. No damage to particle by attrition.
APPLICATIONS:
Drying, heating, cooling, sterilization or ripening process for Polymers, Chemicals and Fertilizers.
CONTINUOUS FLUID BED DRYER
The distributor plate is fixed at the bottom of a rectangular vessel. Hot air is passed through the Distributor
Plate and wet material is led continuously by a screw feeder at constant rate. The air velocity can be varied as
desired. After lapse of designed residence time, the dried product is continuously discharged at the overflow
and underflow outlets. The exhaust air is vented out after processing through a dust separation system.
SALIENT FEATURES:

1. Operation can be easily controlled by adjusting feed and temperature of hot air based on the temperature
at the outlet.
2. Over and under flow features provide uniform drying of small and large size particles.
3. Wet feed is mixed with semi-dried product in the chamber, hence products with higher moisture content
can also be fluidised and dried
4. The drying chamber can be partitioned by baffle plates resulting in more uniform drying.
VIBRATORY FLUID BED DRYER
Vibratory fluidised bed dryer (Patent No. 155757) is an extension of fluidised bed techniques, by using
vibrations as an external aid to fluidisation. All materials cannot be fluidised because of one or more of the
following reasons:
1. Excessive moisture
2. Strong surface forces
3. Wide particle size distribution
4. Fine Powder
5. Other product characteristics
Some of the materials having such properties can also be fluidised well with the aid of mechanical vibrations.
Vibrations breakup the inter particle forces of attraction and improve quality of fluidisation. Bubbling of hot air
in a stationary fluid bed may cause violent agitation. When vibrations are used as an aid, gas velocities are
reduced and the fluidisation is gentle. Particle attrition is reduced. Thus substances having low mechanical
strength can be dried without damage.
There are two methods of imparting vibrations:
a) Constant Force System
b) Constant Displacement System
Choice is exercised based on application.

ADVANTAGES
1. Suitable for materials having wide particle size distribution.
2. Effective fluidisation of difficult materials
3. Low air and energy consumption.
4. Low dust emission because of low air flow rates.
5. Self discharging.
6. Easy control of residence time, product moisture and overall operation.
TYPICAL APPLICATIONS:
 Potassium Chloride
 Common Salt
 Citric Acid
 Urea Pesticides
 Milk Powders
 Instant Coffee
 Tea
 Sugar
 Paddy
 Soya
 Maize
PILOT PLANT TESTS
Design of a commercial size Fluid Bed System is not just heat and mass transfer calculations or sizing. It is an
art! Pilot plant tests, experience and field data are important for designing an optimised Fluid Bed System for

continuous application. Consideration of fluidisation velocity, operating temperature, particle size distribution
of material, distributor plate, bed height and dedusting system require pilot plant tests.
Kilburn Engineering Limited has a fully fledged Test Centre, where exhaustive facilities are available for Pilot
Plant Tests. All variable parameters can be adjusted to study the drying characteristics of a substance and
thereby determine values of important parameters. This data is further supplemented with the empirical and
actual field data.

Project KEL

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