This document discusses various methods for sterilization of liquids and gases. It begins by describing continuous sterilization processes, noting their advantages over batch sterilization. These include simplified production planning and ability to operate at high temperatures for short periods of time. The document then examines different types of continuous sterilization systems and provides an example calculation for sterilizer pipe length. Additional sterilization methods discussed include filtration and various techniques for air sterilization like compression and filtration. Key filtration mechanisms and concerns for air sterilization like pressure drop are also outlined.
Batch and Continuous Sterilization of Media in Fermentation Industry Dr. Pavan Kundur
Continuous sterilization is the rapid transfer of heat to medium through steam condensate without the use of a heat exchanger. ... This is more efficient than batch sterilization because instead of expending energy to heat, hold, and cool the entire system, small portions of the inlet streams are heated at a time.
Process scale-up is a critical activity that enables a fermentation process achieved in research and development to operate at a commercially viable scale for manufacturing.
Batch and Continuous Sterilization of Media in Fermentation Industry Dr. Pavan Kundur
Continuous sterilization is the rapid transfer of heat to medium through steam condensate without the use of a heat exchanger. ... This is more efficient than batch sterilization because instead of expending energy to heat, hold, and cool the entire system, small portions of the inlet streams are heated at a time.
Process scale-up is a critical activity that enables a fermentation process achieved in research and development to operate at a commercially viable scale for manufacturing.
Scale-up and scale-down of chemical processesSeppo Karrila
Explains the path from for example synthesizing a useful appearing material in the lab to actual production of the same. Also explains what pilot machines are, how they are used, and why sometimes down-scaling of a unit operation is done to experiment in bench-scale.
Microbial Kinetics in Batch Culture
Culture system containing a limited amount of nutrient, which is inoculated with the microorganism. Cells grow until some component is exhausted or until the environment changes so as to inhibit growth. Biomass concentration defined in terms of cell dry weight measurements (g/l) or total cell number (cells/ml).
Lineweaver-Burke Equation.....We remember the Monod Equation
Invert…
The equation now has the form of a straight line with intercept.
Y = MX + C
By plotting as a function of
You get a straight line, where the slope is , and the y–axis intercept is .
Product Yield Coefficient
Maintenance:
Cells use energy and raw materials for two functions, production of new cells and the maintenance of existing cells. In general, consumption of materials for maintenance is small w.r.t. the amount of materials used in the synthesis of new biomass.
Generally it is assumed that the use of materials for maintenance is proportional to the amount of cells present.
Downstream processing refers to the recovery and purification of biosynthetic products, particularly pharmaceuticals, from natural sources such as animal or plant tissue or fermentation broth, including the recycling of salvageable components and the proper treatment and disposal of waste.
Bioreactors for animal cell suspension cultureGrace Felciya
1. Types of culture
2. Techniques of cultivating animal cell
3. suspension culture/ Non anchorage dependent
4. Bioreactor consideration
5. Requirements of Bioreactor
6. Reactors used in cultivation
Scale-up and scale-down of chemical processesSeppo Karrila
Explains the path from for example synthesizing a useful appearing material in the lab to actual production of the same. Also explains what pilot machines are, how they are used, and why sometimes down-scaling of a unit operation is done to experiment in bench-scale.
Microbial Kinetics in Batch Culture
Culture system containing a limited amount of nutrient, which is inoculated with the microorganism. Cells grow until some component is exhausted or until the environment changes so as to inhibit growth. Biomass concentration defined in terms of cell dry weight measurements (g/l) or total cell number (cells/ml).
Lineweaver-Burke Equation.....We remember the Monod Equation
Invert…
The equation now has the form of a straight line with intercept.
Y = MX + C
By plotting as a function of
You get a straight line, where the slope is , and the y–axis intercept is .
Product Yield Coefficient
Maintenance:
Cells use energy and raw materials for two functions, production of new cells and the maintenance of existing cells. In general, consumption of materials for maintenance is small w.r.t. the amount of materials used in the synthesis of new biomass.
Generally it is assumed that the use of materials for maintenance is proportional to the amount of cells present.
Downstream processing refers to the recovery and purification of biosynthetic products, particularly pharmaceuticals, from natural sources such as animal or plant tissue or fermentation broth, including the recycling of salvageable components and the proper treatment and disposal of waste.
Bioreactors for animal cell suspension cultureGrace Felciya
1. Types of culture
2. Techniques of cultivating animal cell
3. suspension culture/ Non anchorage dependent
4. Bioreactor consideration
5. Requirements of Bioreactor
6. Reactors used in cultivation
The availability of affordable, high quality, custom gene synthesis has greatly expanded what is possible for labs in numerous research areas. IDT offers a variety of gene synthesis solutions, including our revolutionary double-stranded gBlocks Gene Fragments. In this presentation, Dr Adam Clore discusses the many applications of gBlocks Gene Fragments, such as controls for qPCR and next generation sequencing, and donor templates for homology directed repair in CRISPR experiments. Learn more at www.idtdna.com/gblocks
Analyzing Fusion Genes Using Next-Generation SequencingQIAGEN
Fusion genes are hybrid genes formed by the fusion of two separate genes. Translocation, interstitial deletion and chromosomal inversions are some of the genetic events that can lead to the formation of fusion genes. The occurrence of fusion genes and its implications in cancer have already been known, but the emergence of NGS technology – especially RNA sequencing – offers the potential to detect novel gene fusions. You can learn more about fusion genes and applying NGS to detect them at our upcoming webinar, presented by Raed Samara, Ph.D., QIAGEN’s Global Product Manager for NGS technologies.
In this webinar, Dr. Raed Samara will cover:
1. Fusion genes: what they are and a historical perspective
2. Fusion gene detection: the current status
3. RNA sequencing vs. digital RNA sequencing
4. How to detect and accurately quantify novel fusion genes in your sample
It is the device that utilize specific configuration of N number of cyclones (diameter equal or greater than 300 mm) to treat higher volume of gas efficiently.
High Efficiency Thermal Management TechnologiesPS Lee
Overview of high efficiency thermal management technologies being developed at the Centre for Energy Research & Technology at the National University of Singapore.
In this communication, an attempt has been made to find out the heat transfer coefficients such as internal and external heat transfer modes and thermophysical properties such as dynamic viscosity, density, thermal conductivity, latent heat of evaporation and saturated vapor pressure for active solar distillation system. It is observed that water temperature plays a vital role in the distillate output (the yield) since it increases significantly with the rise of basin water temperature. Double slope step type solar still of area 1 m2 is constructed using a glass pieces. Top Glass cover with 10° slope ensures a very good transmission of solar radiation inside the still. The distillate water productivity is in the range of 2.758 litres to 2.805 liters per day for still performance study. Similarly the instantaneous efficiency for still performance study is in the range of 17.84% to18.25%. Dimensionless numbers such as the Nusselt number (Nu), the Grashof number (Gr), the Reynolds number (Re) and the Prandtl number (Pr) were also estimated. Heat transfer coefficient were estimated for the present system since the system overall efficiency depend on heat transfer modes. Internal (convection, evaporation and radiation) and external (convection, conduction and radiation) heat transfer modes were calculated for the present system and it is found that because of rise in water temperature, evaporative heat transfer coefficient value rises significantly.
Experimental investigate to obtain the effectiveness of regenerator using Air.IJESFT
The regenerator is a kind of heat exchanger that provides a way to get the gas to the low temperature with as much potential work (cooling power) as possible without carrying a lot of heat with it. It doesn’t put heat in or out of the system but it absorbs heat from the gas on one part of the pressure cycle and returns heat to the gas on the other part.
More recent applications of regenerators in cryogenic systems can be found in small cryogenic refrigerators (cryocoolers). Systems such as the Stirling Gifford-McMahon, pulse tube, Solvay, Vuilleumier and magnetic cycle refrigerators all use either a static or rotary regenerator. In fact, the success these coolers have achieved is directly related to the characteristics of compact size and efficiency of the regenerator.
Regenerator effectiveness of 99% results in 21% loss of refrigeration effect, similarly regenerator effectiveness of 98% results in 42% loss of refrigeration effect, with refrigeration effectiveness of 95.238% the loss of refrigeration is 100%. i.e. no net cooling is produced.
In cryogenic applications the regenerator is typically made up of 100 to 500 meshes SS 304, Phosphorous bronze screens or small lead spheres (150 to 300 micro meters) are used, that are tightly packed together and held in place on either end in the same manner.
To develop experimental setup at our laboratory level by using air as working fluid and find out the effectiveness of various regenerative materials is basic goal of this work.
Gas Chromatography is an analytical techniques, used for the separation of volatile substances on the basis of their partition coefficient . In this slide you will find out different instrumentation of gas chromatography, its advantages, disadvantages and moreover its applications.
Engineering of a Microscale Niche for Pancreatic Tumor Cells Using Bioactive ...Arun kumar
Two-photon polymerization has recently emerged as a promising technique to fabricate scaffolds for three-dimensional (3D) cell culture and tissue engineering. Here, we combined 3D-printed microscale scaffolds fabricated using two-photon polymerization with a bioactive layer-by-layer film coating. This bioactive coating consists of hyaluronic acid and poly(l-lysine) of controlled stiffness, loaded with fibronectin and bone morphogenic proteins 2 and 4 (BMP2 and BMP4) as matrix-bound proteins. Planar films were prepared using a liquid handling robot directly in 96-well plates to perform high-content studies of cellular processes, especially cell adhesion, proliferation, and BMP-induced signaling. The behaviors of two human pancreatic cell lines PANC1 (immortalized) and PAN092 (patient-derived cell line) were systematically compared and revealed important context-specific cell responses, notably in response to film stiffness and matrix-bound BMPs (bBMPs). Fibronectin significantly increased cell adhesion, spreading, and proliferation for both cell types on soft and stiff films; BMP2 increased cell adhesion and inhibited proliferation of PANC1 cells and PAN092 on soft films. BMP4 enhanced cell adhesion and proliferation of PANC1 and showed a bipolar effect on PAN092. Importantly, PANC1 exhibited a strong dose-dependent BMP response, notably for bBMP2, while PAN092 was insensitive to BMPs. Finally, we proved that it is possible to combine a microscale 3D Ormocomp scaffold fabricated using the two-photon polymerization technique with the bioactive film coating to form a microscale tumor tissue and mimic the early stages of metastatic cancer.
wo-photon polymerization has recently emerged as a promising technique to fabricate scaffolds for three-dimensional (3D) cell culture and tissue engineering. Here, we combined 3D-printed microscale scaffolds fabricated using two-photon polymerization with a bioactive layer-by-layer film coating. This bioactive coating consists of hyaluronic acid and poly(l-lysine) of controlled stiffness, loaded with fibronectin and bone morphogenic proteins 2 and 4 (BMP2 and BMP4) as matrix-bound proteins. Planar films were prepared using a liquid handling robot directly in 96-well plates to perform high-content studies of cellular processes, especially cell adhesion, proliferation, and BMP-induced signaling. The behaviors of two human pancreatic cell lines PANC1 (immortalized) and PAN092 (patient-derived cell line) were systematically compared and revealed important context-specific cell responses, notably in response to film stiffness and matrix-bound BMPs (bBMPs). Fibronectin significantly increased cell adhesion, spreading, and proliferation for both cell types on soft and stiff films; BMP2 increased cell adhesion and inhibited proliferation of PANC1 cells and PAN092 on soft films. BMP4 enhanced cell adhesion and proliferation of PANC1 and showed a bipolar effect on PAN092. Importantly, PANC1 exhibited a strong dose-dependent BMP response, notably for bBMP2, while PAN092 was insensitive to BMPs. Finally, we proved that it is possible to combine a microscale 3D Ormocomp scaffold fabricated using the two-photon polymerization technique with the bioactive film coating to form a microscale tumor tissue and mimic the early stages of metastatic cancer.
3D collagen fibrillar microstructure guides pancreatic cancer cell phenotype ...Arun kumar
Pancreatic cancer, one of the deadliest cancers, is characterized by high rates of metastasis
and intense desmoplasia, both of which are associated with changes in fibrillar type I collagen
composition and microstructure. Epithelial to mesenchymal transition (EMT), a critical
step of metastasis, also involves a change in extracellular matrix (ECM) context as cells
detach from basement membrane (BM) and engage interstitial matrix (IM). The objective of
this work was to develop and apply an in-vitro three-dimensional (3D) tumor-ECM model to
define how ECM composition and biophysical properties modulate pancreatic cancer EMT.
Three established pancreatic ductal adenocarcinoma (PDAC) lines were embedded within
3D matrices prepared with type I collagen Oligomer (IM) at various fibril densities to control
matrix stiffness or Oligomer and Matrigel combined at various ratios while maintaining constant
matrix stiffness
A protamine-conjugated gold decorated graphene oxide composite as an electroc...Arun kumar
In this study, an effective electrochemical sensor was developed for heparin detection using a protamineconjugated
graphene oxide/gold (GO/Au) composite. Protamine is an antidote that can act as an affinity ligand
for heparin. The GO was used as support for signal amplification, and Au nanoparticles (NPs) were employed
to immobilize the protamine. This Au NPs also increasing the electron transfer rate and enhancing the signal response
during protamine-heparin integration. The proposed affinity sensor had a simple fabrication process, a
low detection limit (0.9 nM), a wide linear range (1.9 × 10−7 M to 1.5 × 10−9 M), high stability, and high selectivity
in the detection of heparin.
3D tumor spheroid models for in vitro therapeutic screening: a systematic app...Arun kumar
The potential of a spheroid tumor model composed of cells in different proliferative and metabolic
states for the development of new anticancer strategies has been amply demonstrated. However, there
is little or no information in the literature on the problems of reproducibility of data originating from
experiments using 3D models. Our analyses, carried out using a novel open source software capable of
performing an automatic image analysis of 3D tumor colonies, showed that a number of morphology
parameters affect the response of large spheroids to treatment. In particular, we found that both
spheroid volume and shape may be a source of variability. We also compared some commercially
available viability assays specifically designed for 3D models. In conclusion, our data indicate the need
for a pre-selection of tumor spheroids of homogeneous volume and shape to reduce data variability to
a minimum before use in a cytotoxicity test. In addition, we identified and validated a cytotoxicity test
capable of providing meaningful data on the damage induced in large tumor spheroids of up to diameter
in 650 μm by different kinds of treatments.
Covalent Triazine Polymer–Fe3O4 Nanocomposite for Strontium Ion Removal from ...Arun kumar
A microporous covalent triazine polymer (CTP) is synthesized via a Friedel–Crafts reaction and used as a solid support to immobilize magnetite Fe3O4 nanoparticles. Thermogravimetric analysis shows that approximately 60 wt % Fe3O4 is loaded onto the composite, and transmission electron microscopy analysis illustrates that the Fe3O4 nanoparticles are uniformly impregnated into the CTP surface. The CTP–Fe3O4 nanocomposite is an efficient adsorbent for the removal of strontium ion (Sr2+) from seawater. Response surface methodology, employed to optimize the removal of Sr2+, confirms that the optimal conditions for this removal are 0.55 mg, pH 7, 40 °C, and 250 min. The experimental results illustrate that the adsorption process fits well with the Freundlich isotherm, with a correlation coefficient of 0.976 and a maximum adsorption capacity of 128 mg g–1. The kinetic study demonstrates that the adsorption behavior follows pseudo-second-order kinetics. The adsorbent is easily recovered from seawater using an external magnetic field, thereby offering facile and economic separation of the adsorbent.
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Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
1. R. Shanthini
25 Nov
1
Sterilization (continued)
CP504 – Lecture 17
- Learn about thermal sterilization of liquid medium
- Learn about air sterilization
- Learn to do design calculations
2. R. Shanthini
25 Nov
2
Continuous Sterilization:
- Simplifies production planning
- Therefore gives maximum plant utilization and minimum
delays
- Provides reproducible conditions
- Can be operated at high temperature (1400
C)
- Therefore sterilization time can be reduced (2 to 3 min)
- Requires less steam and less cooling water
- Suitable when the capacity of operation is high
- High initial capital investment (use of aseptic transfer system
for the sterile broth to be transported to a sterile vessel)
3. R. Shanthini
25 Nov
3
Continuous Sterilization:
It is the only option if the medium is to be exposed to high
temperatures for a short time (HTST process) to avoid
denaturation of proteins or to avoid destruction of some of
the enzymes, etc., since it is not possible in commercial
scale operations in batch sterilization to quickly heat large
volumes of the medium in short time and cool it also in short
times.
4. R. Shanthini
25 Nov
4
Continuous Injection Type
Holding section
(where most of the
sterilization takes place)
Steam
Raw
medium Expansion
valve
vacuum
Flash
cooler
Sterile
medium
- Direct steam injection for heating
(relatively a rapid process)
- Flash cooling (rapid process)
Continuous Sterilization:
5. R. Shanthini
25 Nov
5
Continuous Sterilization:
- Capital investment is low
- Easy to clean and maintain the system
- Heating and cooling periods are shorter
- Steam efficiency is very high as live steam is directly injected
into the medium
- Direct contact of the steam with the medium makes it
necessary that the steam should be clean and free of any anti-
corrosive agents
- Foaming may occur during both heating and cooling
Continuous Injection Type
6. R. Shanthini
25 Nov
6
Continuous Heat Exchanger Type
Raw medium
Holding section
Sterile
medium
Cooling water
Steam
Indirect steam
heating in
plate-and-frame (or
shell-and-tube)
heat exchanger
Continuous Sterilization:
7. R. Shanthini
25 Nov
7
Continuous Heat Exchanger Type
Continuous Sterilization:
plate-and-frame heat exchanger has larger heat transfer area
than shell-and-tube heat exchanger, and therefore more
effective
plate-and-frame heat exchanger is favourable with high
viscous system
plate-and-frame heat exchanger is limited to lower pressures
(less than 20 atm) due to its weak structural strength
8. R. Shanthini
25 Nov
8
Most of the sterilization in the continuous sterilization process
may occur in the holding section.
Therefore
∇hold
ln
no
nt
=
λ
hold
L
uav
Since the holding section is a long pipe,
=
length of the pipe
average fluid velocity
in the pipe
Continuous Sterilization:
= kd λhold = kd0 exp(-Ed/RT) λhold
9. R. Shanthini
25 Nov
9
uav
The ratio of average velocity to maximum velocity
umax
= 0.5 for laminar flow of Newtonian fluids
through a smooth round pipe
0.75 for turbulent flow=
0.87 for turbulent flow with the Reynolds
Number of 1000,000
=
Therefore, using the average velocity to calculate
the length of the pipe required for sterilization may
leave some portion of the medium understerilized,
which may cause contamination problem
Continuous Sterilization:
10. R. Shanthini
25 Nov
10
Example 10.4: Estimating the time required for continuous sterilization
A continuous sterilizer with a steam injector and a flash cooler
will be employed to sterilize medium continuously with the flow
rate of 2 m3
/h. The time for heating and cooling is negligible with
this type of sterilizer. The typical bacterial count of the medium is
about 5 x 1012
per m3
, which needs to be reduced to such an
extent that only one organism can survive during two months of
continuous operation. The sterilizer will be constructed with the
pipe with an inner diameter of 0.102 m. Steam at 600 kPa
(gauge pressure) is available to bring the sterilizer to an
operating temperature of 125o
C. For the heat resistant bacterial
spores: kdo = 5.7 x 1039
per h; Ed = 2.834 x 105
kJ / kmol. For the
medium: c = 4.187 kJ/kg.K; ρ = 1000 kg/m3
; μ = 4 kg/m.h.
a) What length should the pipe be in the sterilizer if you assume
ideal plug flow?
b) What length should the pipe be in the sterilizer if the effect of
axial dispersion is considered? Assume an axial dispersion
coefficient of 20 m2
/h.
11. R. Shanthini
25 Nov
11
Problem statement: The typical bacterial count of the medium
is about 5 x 1012
per m3
, which needs to be reduced to such an
extent that only one organism can survive during two months
of continuous operation.
∇ ln
n0
nt
= = 37.2 = kd dt
∫0
t
= ln
144x1014
1
n0 = (5 x 1012
per m3
) x (2 m3
/h) x (24 h/day) x (60 days)
= 14400 x 1012
nt = 1
Solution to Example 10.4:
The above integral should give 37.2.
12. R. Shanthini
25 Nov
12
a) Since the temperature at the holding section in constant,
Solution to Example 10.4:
∇hold
= kd λhold = 37.2
For the given data,
kd = kd0 exp(-Ed/RT)
= (5.7 x 1039
per h) exp[- 2.834x105
/ 8.314x(273.15+125)]
= 375.3 per h
Therefore, λhold = 37.2 / kd = 37.2 / 375.3 per h = 0.099 h
Length of the pipe, L = velocity through the pipe x λhold
= velocity through the pipe x 0.099 h
13. R. Shanthini
25 Nov
13
Since plug flow is assumed,
velocity through the pipe =
Solution to Example 10.4:
Therefore, L = (245 m/h) x (0.099 h) = 24.26 m
2 m3
/h
π (0.102/2)2
m2
= 245 m/h
What happens if the flow is not plug flow?
14. R. Shanthini
25 Nov
14
b) If axial dispersion is considered, then we use the following
table:
Solution to Example 10.4:
kd L
uav
nt
n0
uav L
D
Peclet number =
Axial dispersion
coefficient
15. R. Shanthini
25 Nov
15
Solution to Example 10.4:
uav L
D
Peclet number = =
(245 m/h) x ( L m)
(20 m2
/h)
kd L
uav
X-coordinate = =
(375.3 per h) x ( L m)
(245 m/h)
nt
n0
Y-coordinate = is obtained from the table
16. R. Shanthini
25 Nov
16
Solution to Example 10.4:
uav L
D
Peclet number = =
(245 m/h) x ( 25 m)
(20 m2
/h)
kd L
uav
X-coordinate = =
(375.3 per h) x ( 25 m)
(245 m/h)
nt
n0
Y-coordinate = =
If L = 25 m is tried, we get
= 306
= 38.3
> 6.9 x 10-17
17. R. Shanthini
25 Nov
17
Solution to Example 10.4:
uav L
D
Peclet number = =
(245 m/h) x ( 27.5 m)
(20 m2
/h)
kd L
uav
X-coordinate = =
(375.3 per h) x ( 27.5 m)
(245 m/h)
nt
n0
Y-coordinate = =
If L = 27.5 m is tried, we get
= 337
= 42.1
> 6.9 x 10-17
18. R. Shanthini
25 Nov
18
Filtration:
Sterilize solutions that may be damaged or denatured by
high temperatures or chemical agents.
The pore size for filtering bacteria, yeasts, and fungi is in
the range of 0.22-0.45 μm
The pore size for filtering viruses and some large proteins
is in the range of 0.01 μm
19. R. Shanthini
25 Nov
19
Methods for gas (air) sterilization:
- Aerobic fermentation require huge volumes of air (a
50,000 L fermenter requires 7x106
to 7x107
L per day
of air) which must be sterilized.
- Adiabatic compression of process air can increase air
temperature (150o
C to 220o
C). A temperature typically
of 220o
C for 30 s is required to kill spores.
- An air-filtration step is almost always used to ensure
sterility of process air.
- Depth filters use glass wool, and rely on inertial
impaction, interception, diffusion and electrostatic
attraction (explained later).
- Surface filters using membrane cartridges use the
sieving effect (explained later).
21. R. Shanthini
25 Nov
21
Inertial impaction (or impingement) occurs when a particle
travelling in the air stream and passing around a fibre,
deviates from the air stream (due to particle inertia) and
collides with the fibre.
Impaction is the dominant collection mechanism for
particles larger than 0.2 μm.
It is important in removing bacteria.
Filtration mechanisms operating in depth filters
22. R. Shanthini
25 Nov
22
Filtration mechanisms operating in depth filters
Interception occurs when a large particle, because of its
size, collides with a fibre in the filter that the air stream is
passing through.
Interception is the dominant collection mechanism for
particles greater than 0.2 μm.
It is important in removing bacteria.
23. R. Shanthini
25 Nov
23
Filtration mechanisms operating in depth filters
Diffusion occurs when the random (Brownian) motion of a
particle causes that particle to contact a fibre.
Diffusion is dominant for particles less than 0.2 μm.
It may be important for virus removal, but bacteria are
sufficiently large that diffusion is relatively unimportant.
24. R. Shanthini
25 Nov
24
Electrostatic attraction plays a very minor role in mechanical
filtration. After fibre contact is made, smaller particles are
retained on the fibres by a weak electrostatic force.
Filtration mechanisms operating in depth filters
26. R. Shanthini
25 Nov
26
Concerns in air sterilization:
Pressure drop is critical in a filter.
Energy input for compressed air for a commercial-scale
process is significant.
Air treatment can account for 25% of total production
costs.
Design engineer has to balance the assurance sterility
against the pressure drop.