Design of Fermenter (1)(1)

8/13/2019 Design of Fermenter (1)(1)

1/44

Design of fermenter


2/44

Fermenter Design

Hiba Mujeeb

Imtisal-e-Noor

Taibah JafferyArooj Fatima


3/44

Fermenter

The main function of a fermenter is toprovide a controlled environment for the

growth of microorganisms or animal cells,

to obtain a desired product.


4/44

In designing and constructing a fermenter

following points must be considered

Capable of being operated aseptically

Long-term operation reliability

Meet the requirements ofcontainment regulations.

Adequate aeration and agitation


5/44

suitable for a range of

processes

smooth internal surfaces, usingwelds instead of flange joints

Low power consumption

Temperature control


6/44

Use of cheap materials

pH control

Sampling facilities

Minimum evaporation losses

Minimal use of labor in operation,harvesting, cleaning and maintenance


7/44

Construction materials

On pilot and large scale, any materials used will have to beassessed on their ability to withstand

Pressure Sterilization Corrosion Toxicity Cost

On a smallscale

Glass and/orstainless steelcan be used


8/44

Temperature control

Thermostaticallycontrolled bath

Internal heatingcoils

Heating jacketSilicone heating

jacket

On a lab scaleLittle heat is normally generated and extra heat has to be provided by using:


9/44

Aeration

andAgitation


10/44

Purpose ofAeration

Providemicroorganisms in

submerged culturewith sufficient oxygen

Purpose ofAgitation

Ensures that auniform suspension

of microbial cells isachieved


11/44

The structural components of the fermenter

involved in aeration and agitation

Theagitator

(impeller)

Stirrerglands and

bearings

Baffles

Theaerationsystem

(sparger)


12/44

Agitator

The agitator is

required toachieve a numberof mixingobjectives

bulk fluid and gas-phase mixing

air dispersion

oxygen transfer

heat transfer

suspension ofsolid particles

maintaining auniform

environment


13/44

Classification of Agitator

Disc turbines

Vaned discs

Open turbines of variable pitch

Propellers


14/44

Stirrer glands and bearingsFour basic types of seal assembly

Shaft is sealed by several layers of packing rings of asbestos or cottonyarn, pressed against the shaft by a gland follower

Sufficient for the requirements of GILSP containment

Stuffing box(packed-gland seal)

Uses where seal is subjected to the contaminationSimple bush seal

Composes of two parts, one part is stationary in the bearing housing,the other rotates on the shaft, and the two components are pressed

together by springs or expanding bellows. Uses in small as well as large fermentation processesMechanical seal

Consists of two magnets: one driving magnet connected by a driveshaft and one driven magnet is placed on one end of the impellershaft

Due to magnetic drive, impeller shaft does not pierce the vessel

Magnetic drive


15/44

Baffles

Four baffles are normally incorporated into

vessel of all sizes to prevent a vortex & to

improve aeration efficiency.

The agitation increases with wider baffles but

drops sharply with narrow baffles.


16/44

Aeration system (Sparger)

Basically it is a device for injecting gas into a

liquid or for spraying a liquid onto a solid.

In fermentation processes, it is used to

introduce air into fermenter for the organisms


17/44

Types of Spargers

Made of sintered glass, ceramics or metal.

Uses only in lab scale-non agitated vesselPorous Sparger

It is a perforated pipe kept below the impeller in the formof crosses or rings.

Uses in small stirred with or without agitation.Orifice Sparger

It is single open/partially closed pipe positionedcentrally below the impeller

Mostly used in large scaleNozzle Sparger

This is air supply via hallow agitator shaft. The airis emitted through holes in the disc or blades of

agitator

Combined

Sparger agitator


18/44

Aseptic

Operation &Containment


19/44

Aseptic

Operation

Preventing the entryof unwantedmicroorganisms

Process Requirement

Wastage of media

Contaminant outgrowth

Product degradation

Lysis of culture

Containment

Preventing the

escape of themicroorganismsfrom the fermentorto the surroundings

Health and Safety

Pathogenicity/virulence oforganisms - infections

Aerosol Generation

Spilled and spent Media


20/44

Fermenter Joints Shafts

PipingFeed

Ports

Sampling

Ports

Sensor

Probes

Foam

Breakers

Air Supply

Exhaust

Gas


21/44

Isolation Sterilization


22/44

Isolation

Joints

Welded

Flanged andSealed with O-

ring seals

Shafts

Double actingmechanicalseals withsteam orcondensate inbetween

Piping

Steam Barrier

SimpleConstruction

Should slopetowardsdrainage

Foam Breaker Impact

MechanismFoambreaker

Turbosep

Sensor Probes

Seals


23/44

Joints

WeldedJoint

O-Ring


24/44

FoamBreaker

Steam

Barrier


25/44

Sterilization

Filtration

Radiation

Ultrasonictreatment

ChemicalTreatment

Heat/UHT

Steam


26/44

Sterilization

Air Supply

Steam jacketedair filter

Simple steamsterilized air

filter unit byRichard

Sampling Ports

Parker

End of the samplingport submerged in40% formalinnormally

WernerMX-3 rotary valve

Jannsen

Exhaust Gas 0.2-m filters on

the outlet pipe

Cyclone separator(solid)

Coalescer(liquids)

Fermenter Steam sterilizable

Should withstandsteam pressure

Pressure relieffacilities

Jacket or coils

Feed Ports

aseptic piercing ofmembranes orconnections with

steam locks Separately

autoclaved siliconetubes


27/44

Air Supply

Richards Unit Steam Jacketed System


28/44

Janssens Sampling System for

containment of microorganisms


29/44

Common Sterilization

Equipment

Filtration

Glass wool, glass fibre ormineral slag wool

Cartridge typefilters/membrane cartridgesfitted into steam sterilizablecasing

Mechanisms

Inertial impaction. Diffusion.

Electrostatic attraction.

Interception

Types

Absolute filters

Depth filters

Steam

Steam Spargers (in situ)

Separate Cooker Indirect Heat Exchanger

(e.g. spiral, plate andframe)

Steam jacketing

Coils

Autoclave Steam injector (venturi

valve) and flashcooler/expansionchamber

Heat/UHT

Steam Electric Element

Indirect Heat Exchanger(for heat exchange withsterile stream)

Heating Jacket


30/44

Valves

and

Steam Traps


31/44

VALVES

Valves are used

for controlling theflow of liquids and

gases.


32/44

Simple ON/OFF valveswhich are either fully

open or fully closed

Valves which providecoarse control of flow

rates

Valves which may beadjusted very precisely so

that flow rates may be

accurately controlled

Safety valves which areconstructed in such a waythat liquids or gases will

flow in only one direction

VALVE TYPES:

Based on FlowControl

Valve Pro Con Application Blocking


33/44

Type

pp g

element

Gate Pminimalsimple

Poor flow

regulating

not for aseptic

conditions

on/off on steam or

water lines

Sliding disk

Globe Rapidly adjustable P highnot for aseptic

conditions

Flow regulation Plug/

horizontal disk

Piston very efficient inaseptic operation

P high

blockage problems

Flow regulation piston

NeedleAccurate control of

flow

limited

aseptic applications

fine control of

steam or liquid flow

tapered plug/

needle

Plug quick to operatePminimal

protected Seals

positive closure

tendency to leak or

seize up

good flow control parallel or

tapered plug

Valve Pro Con Application Blocking


34/44

Type

pp g

element

Ball excellent flowpath

handle mycelial

brothsHandle high

temps and

Pressures

The pressure and

temperature range

is limited by the

PTFE seat and stemseals

suitable for aseptic

operation

stainless-

steel ball

Butterfly No absoluteclosure

not suitable for

aseptic operation

in large diameter

pipes at low pressure

Rotating disk

Pinch The flow rate canbe controlled

from 10 to 95%

of rated flow

capacity

must be

checked regularly

for signs of wear

aseptic operation with

fermentation broths,

even when mycelial

flexible

sleeve

closed by a

pair of pinch

bars

Diaphragm provideddiaphragm

material will

withstand

Repeatedsterilization

Diaphragm failure

more complex

expensive

very suitable for

aseptic operation

ON/OFF

flow regulation

steam services

flexible

closure/quick

action lever


35/44

Suitable Valves by Application

ON/OFF

Globe

Butterfly

CRUDE

FLOWCONTROL

Gate valves

ACCURATE

FLOWCONTROL

Needlevalves

STERILE

USES

Ball

Pinch

Diaphragm

S i l V l


36/44

Special Valves

The purpose of the check valve is to prevent accidental

reversal of flow of liquid or gas in a pipe due to break downin some part of the equipmentCheck valve

Pressure-reduction valves are incorporated into pipelineswhen it is necessary to reduce from a higher to a lower

pressure and maintain the lower pressure in thedownstream side

Pressure

Reduction Valves

A pressure-retaining valve will maintain pressure thepipeline upstream of itself

Pressure

Retaining Valves

must be incorporated into every air steam line and vesselwhich is subject to pressure ensure that the pressure willnever exceed the upper limit

Safety valves


37/44

Steam traps

In all steam lines steam condensate needs to beremoved to ensure optimal process conditions

Steam traps collect and remove automatically any

condensate present in the lines

Basis of operation

Density of fluid by using a float (float type)

Temperature of fluid, present in thermostatic

and balanced steam traps

Measuring kinetic effects

i


38/44

Provides an opening forremoval of condensate

Opening may be open/close

May be varied continuously to

provide uniform rate of flow

Valve andseat

assembly

Which will open or close thevalve

By measuring some parameterof the condensate reaching it

Openingand Closing

Device

Construction

H t t k


39/44

How a steam trap works


40/44

Balanced pressure steam trap

Armer (1991)thinks thatbalanced

pressurethermostatictraps are themost suitable

for autoclavesand sterilizers

i ll l d b l d


41/44

Hermetically sealed balanced

pressure steam trap

SarcoLtd

(Cheltenham, U.K.)

make a (Model No.

SBP 30; Fig.7.42)which has been

used with a high

containment levelpilot-plant

fermenter

Any steam condensate may be


42/44

Any steam condensate may be

returned to the boiler

used in a steam

condensate line

vented to waste or

piped to a kill tank in acontainment location


43/44

Testing a Fermenter

When a new fermenter (10 dm3 or larger) hasfinally been assembled in a factory it must behydraulically pressure tested and checked by

independent inspectors using nationallyapproved test procedures.

A vessel which has passed the approved testsis given a certificate which is recognized by

insurance companies which will allow it to beoperated in a laboratory or factory


44/44

Design of Fermenter (1)(1)

Documents

Transcript of Design of Fermenter (1)(1)