Definition of drying
Importance of drying
Difference between drying and evaporation
Drying is defined as removal of the liquid from a material by application of heat & is accomplished by transfer of a liquid from the surface into an unsaturated vapor phase .
Drying is the final removal of water from material (usually by heat)
Drying is commonly the last stage in a manufacture process
Non-thermal drying
1- As Squeezing wetted sponge
2- Adsorption by desiccant (desiccation)
3- Extraction.
Preservation of drug products
Preparation of bulk drugs
Improved handling
Improved characteristics
Equipments
Drying is necessary in order to avoid deterioration. A few examples are…
--blood products, tissues… undergo microbial growth
--effervescent tablets, synthetic & semi synthetic drugs undergo…. chemical decomposition.
objectives, applications, mechanism of size separation, the official standard of powders, sieves, sieve shaker, cyclone separator, air separator, bag filter, elutriation tank
Objectives, applications, Mechanism, official standards of powders, Sieve, Standard for Sieve, Principles, construction, working, uses, merits and demerits of Air separator.
This presentation will help the students of Pharmacy in subjects like Pharmaceutics and industrial pharmacy. Hope you will find it better and helpful.
Regards
Amjad Anwar
email: amjadanwar77@gmail.com
Department of Pharmacy, University Of Malakand
Mixer Machines Mixer Machines are used in a number of different applications and industries in order to produce a final product that is the result of mixing or combining two or more materials.
Fluid energy mill for pharmacy principles, construction, working, uses, meri...ASHUTOSH SENGAR
this is an slideshare for pharmacy students, principles, construction, working, uses, merits and
demerits of , fluid energy mill its for b. pharm. and M. PHARM
objectives, applications, mechanism of size separation, the official standard of powders, sieves, sieve shaker, cyclone separator, air separator, bag filter, elutriation tank
Objectives, applications, Mechanism, official standards of powders, Sieve, Standard for Sieve, Principles, construction, working, uses, merits and demerits of Air separator.
This presentation will help the students of Pharmacy in subjects like Pharmaceutics and industrial pharmacy. Hope you will find it better and helpful.
Regards
Amjad Anwar
email: amjadanwar77@gmail.com
Department of Pharmacy, University Of Malakand
Mixer Machines Mixer Machines are used in a number of different applications and industries in order to produce a final product that is the result of mixing or combining two or more materials.
Fluid energy mill for pharmacy principles, construction, working, uses, meri...ASHUTOSH SENGAR
this is an slideshare for pharmacy students, principles, construction, working, uses, merits and
demerits of , fluid energy mill its for b. pharm. and M. PHARM
Refractance window drying is a novel
fourth-generation drying technology that is employed to dry heat-sensitive products like juices and purees to retain the product colour, aroma, antioxidant compounds, and nutritional properties. it is a thin film drying system having high heat and mass transfer rates that speed up the rate of drying at a comparatively lower temperature.In this technology, drying of product is done using thin, transparent infrared film which eventually forms a "window" for drying, it assures very low-temperature drying with
rapidity, with all modes of heat transfer.
introduction, theory of drying, applications of drying, construction & working about fluidised bed dryer,use of tray dryer,construction about vacuum dryer, construction & working about drum dryer, construction about spray dryer
The branch of chemistry, which deals with the study of reaction rates and their mechanisms, called chemical kinetics.
Thermodynamics tells only about the feasibility of a reaction whereas chemical kinetics tells about the rate of a reaction.
For example, thermodynamic data indicate that diamond shall convert to graphite but in reality the conversion rate is so slow that the change is not perceptible at all.
The state where the concentrations of all reactants and products remain constant with time.
On the molecular level, there is frantic activity. Equilibrium is not static, but is a highly dynamic situation.
law of mass action-
jA + kB lC + mD
where A, B, C, and D represents chemical species and j, k, l, and m are their coefficient in the balanced equation.
The law of mass action is represented by the equilibrium expression:
The square brackets indicate the concentrations of the chemical species at equilibrium, and K is a constant called the equilibrium constant.
Introduction
Basis
Importance
Classification
Homogeneous catalysis
Mechanism
Example
Heterogeneous catalysis
Mechanism
Examples
Promoters
Catalytic Poisoning
Autocatalysis
Enzyme catalysis
Enzymes
References
Catalyst: -
The substances that alter the rate of a reaction but itself remains chemically unchanged at the end of the reaction is called a Catalyst.
The process is called Catalysis.
prop-
A catalyst cannot start the reaction by itself.
Catalytic activity increases as surface area of catalyst increases.
Catalysts are thermolabile, this effect is very well pronounced in enzymes.
Catalytic activity is maximum at a catalyst’s optimum temperature.
A catalyst does not alter the position of the equilibrium, instead it helps in achieving the equilibrium faster.
content-
Chemistry & Chemical Engineering
History of Catalysis
Catalysis
Recent trends in Catalysis
Future trends in Catalysis
Summary
role-
24% of GDP from Products made using catalysts (Food, Fuels, Clothes, Polymers, Drug, Agro-chemicals)
> 90 % of petro refining & petrochemicals processes use catalysts
90 % of processes & 60 % of products in the chemical industry
> 95% of pollution control technologies
Catalysis in the production/use of alternate fuels (NG,DME, H2, Fuel Cells, biofuels…)
Type of adsorption- Pharmaeutical Physical ChemistrySanchit Dhankhar
Adsorption
Adsorption versus absorption, Desorption
Types of adsorption: Physisorption and Chemisorption
Factors affecting adsorption
Adsorption isotherms: Freundlich and Langmuir
Gibbs adsorption isotherm
Bet equation and its use in surface area determination
Applications
ADSORPTION
Adsorption is the process in which matter is extracted from one phase and concentrated at the surface of a second phase. (Interface accumulation). This is a surface phenomenon as opposed to absorption where matter changes solution phase, e.g. gas transfer. This is demonstrated in the following schematic.
Viruses of Prokaryotes:
T4 phage
M13 (General properties and structure,classification,reproduction)
Viruses of Eukaryotes:
Retrovirus
Herpes simplex virus (Classification, reproduction )
Plant viruses:
TMV (Morphology, taxonomy, and reproduction)
Viroids and prions
A virus is a non-cellular particle made up of genetic material and protein that can invade living cells.
Killing or removing all forms of microbial life (including endospores) in a material or an object.
Mainly due to: oxidation of cell component, denature proteins, nucleic acids, RNA and loss of membrane permeability.
Procedures performed in a way to prevent contamination with infectious microorganisms
Used to prevent contamination of surgical instruments, medical personnel, and the patient during surgery
Sanitization: Lowering of microbial counts to prevent transmission in public setting (e.g., restaurants & public rest rooms)
Degerming: Mechanical removal of microbes from limited area. e.g., Alcohol swab on skin, washing of hands with soap
Sepsis: Bacterial contamination
Antisepsis: Reduction or Inhibition of microbes found on LIVING TISSUE
Smear preparation:
A drop of water is placed in the centre of a slide
One loopfuls of organisms is transferred to the centre of slide
Spread the organisms over the slide
The smear is allowed to dry
Slide is passed through flame several times to heat-kill and fix organisms
A bacterial stain is stained with crystal violet (fuchsin, methylene blue) 1 min
Observe under microscope
Basic Dyes
Methylene Blue
Crystal Violet
Carbol Fuchsin
Safranin
Malachite Green
Acidic Dyes
Picric Acid
Nigrosin
India Ink
Eosin
differrential statining
Two or more reagents Distinguish
Bacterial groups
Specific Structures
Example
Gram stain
Acid Fast Stain
Poliomyelitis, often called polio is an infectious disease caused by the poliovirus.
In about 0.5% of cases there is muscle weakness resulting in an inability to move.
It may also be spread by food or water containing infected human feces & less commonly from infected saliva.
Enterovirus (RNA)
Three serotypes: 1, 2, 3
Rapidly inactivated by heat, formaldehyde, chlorine, ultraviolet light.
Polio vaccines are vaccines used to prevent poliomyelitis (polio).
The World Health Organization recommends all children be vaccinated against polio.
Polio vaccines are generally safe to give during pregnancy & in those cases who have HIV/AIDS .
Changes in the nucleotide sequence of DNA
May occur in somatic cells (aren’t passed to offspring)
May occur in gametes (eggs & sperm) and be passed to offspring
Changes in the nucleotide sequence of DNA
May occur in somatic cells (aren’t passed to offspring)
May occur in gametes (eggs & sperm) and be passed to offspring
Changes in the nucleotide sequence of DNA
May occur in somatic cells (aren’t passed to offspring)
May occur in gametes (eggs & sperm) and be passed to offspring
Mutations happen regularly
Almost all mutations are neutral
Chemicals & UV radiation cause mutations
Many mutations are repaired by enzymes
Some type of skin cancers and leukemia result from somatic mutations
Some mutations may improve an organism’s survival (beneficial)
chromosome mutations=
Five types exist:
Deletion
Inversion
Translocation
Nondisjunction
Duplication
The inhibition of growth under standardized conditions may be utilized for demonstrating the therapeutic efficacy of antibiotics.
Any subtle change in the antibiotic molecule which may not be detected by chemical methods will be revealed by a change in the antimicrobial activity and hence microbiological assays are very useful for resolving doubts regarding possible change in potency of antibiotics and their preparations.
principle;
The microbiological assay is based upon a comparison of the inhibition of growth of micro-organisms by measured concentration of the antibiotics to be examined with that produced by known concentrations of a standard preparation of the antibiotic having a known activity.
Two general method are usually employed:-
The cylinder-plate (or cup-plate) method.
The turbidimetric (or tube assay) method.
The process of growing microorganisms in culture by taking bacteria from the infection site (in vivo or environment) and grow them in artificial environment in the laboratory (in vitro).
Bacteria may require adequate nutrition, optimum pH, temperature and oxygen for growth and multiplication.
Suitable artificial media containing sources of carbon, nitrogen, hydrogen, oxygen, phosphorous and other elements such as sodium, potassium, magnesium, iron and growth factor (Vitamins) in very small amounts have been used for cultivation of microorganism.
When microorganisms are cultivated in the laboratory, a growth environment called a medium is used. The medium may be purely chemical (a chemically defined medium), or it may contain organic materials, or it may consist of living organisms such as fertilized eggs.
Microorganisms growing in or on such a medium form a culture.
A culture is considered a pure culture if only one type of organism is present and a mixed culture if populations of different organisms are present.
When first used, the culture medium should be sterile, meaning that no form of life is present before inoculation with the microorganism.
Types of Pathogenic Organisms
Viruses
Bacteria
Protozoan
Fungi
Animal
Parasites
mecahnism
Utilization of host nutritional resources
Physical damage to host tissues
Production of toxic substances
Chromosomal and gene damage
Body cells behave abnormally
Antigens
Some chemical that creates immune response
Most are proteins or large polysaccharides from a foreign organism.
Microbes: Capsules, cell walls, toxins, viral capsids, flagella, etc.
Nonmicrobes : Pollen,, serum proteins, and surface molecules from transplanted tissue.
Antigens
Some chemical that creates immune response
Most are proteins or large polysaccharides from a foreign organism.
Microbes: Capsules, cell walls, toxins, viral capsids, flagella, etc.
Nonmicrobes : Pollen,, serum proteins, and surface molecules from transplanted tissue.
Skin acts as barrier to microbes and viruses
- sweat has a low pH
Mucus traps foreign particles
Tears
- Lysozyme has antimicrobial action
Gastric stomach acid
2nd line of defence
Phagocytic cells (WBCs)
Natural Killer (NK) Cells: attack virus infected cells
Inflammatory Response
Antimicrobial proteins
Lysozyme
Interferon
Antibodies
History of microbiology- Pharmaceutical MicrobiologySanchit Dhankhar
Scientific study of organisms (both eukaryotes and prokaryotes) and agents too small to be seen clearly by the unaided eye.
Microbiology is the study of microorganisms / microbes which is visible only with a microscope.
Derived from the Greek word “mikros” - ‘small’ and “bios” - ‘life’.
The diverse group of organisms includes algae, archae, bacteria, cyanobacteria, fungi, protozoa, viruses.
Most of the microorganisms are harmless.
99% are good. Eg: Cynobacteria (blue green algae)
1% are bad. Eg: Pathogens
The belief in the spontaneous generation of life from nonliving matter was introduced by Aristotle, who lived around 350 BC.
According to Aristotle, it was:
“readily observable that aphids arise from the dew which falls on plants, fleas from putrid matter, mice from dirty hay.”
This belief remained unchallenged for more than 2000 years.
Formation of life from non living things- ABIOGENESIS.
Aristotle suggested that flies and maggots developed from decaying organic matter.
Epicuris suggested that worms and other animals originated from soil and manure by the action of sun and rain.
Theory of Spontaneous generation was disproved by Francesco Redi,Lazzaro Spallanzani,Louis Pasteur and Theodore Schwann.They argued that life originated from “pre existing life only”-BIOGENESIS.
Francesco Redi took 3 containers filled with meat particles.1st was kept unclosed,2nd covered with paper and 3rd was covered with cork or guaze.After inhibition the 1st container had maggot being produced because flies were attracted by the odour of the meat and they laid eggs after some days developed to maggots.2nd and 3rd container did not contain maggots.
Theory of Spontaneous generation was disproved by Francesco Redi,Lazzaro Spallanzani,Louis Pasteur and Theodore Schwann.They argued that life originated from “pre existing life only”-BIOGENESIS.
Francesco Redi took 3 containers filled with meat particles.1st was kept unclosed,2nd covered with paper and 3rd was covered with cork or guaze.After inhibition the 1st container had maggot being produced because flies were attracted by the odour of the meat and they laid eggs after some days developed to maggots.2nd and 3rd container did not contain maggots.
DISINFECTANTS are chemical agents that inhibit or kill microorganisms (surgical apparatus, periphery of the patient, and the objects used by the patient).
Disinfection It is the application of chemicals to destroy most pathogenic organisms on inanimate surfaces
Can be accomplished by application of chemical agents, use of physical agents (ionizing radiation) dry or moist heat, superheated steam(autoclave, 120̊ C)
idela surfactant
effective at room temperature,
noncorrosive and nontoxic,
inexpensive,
capable of killing the vegetative form of all pathogenic organisms,
require limited time of exposure
It is an antibiotic that was the first drug to be successful against tuberculosis but now it is used with other drugs because of its toxic effects
othere uses
Anti TB drug
Plaque
Veterinary treatment against gram negative bacteria in horses , cattle , sheep
Fermentation is defined as chemical transformation of organic compound brought about through agency of microorganisms
Microorganisms useful in fementation can be either prokaryotes such as bacteria , virus or eukaryotes such as fungi; yeast
Test Organism-Streptomyces griseus
Penicillin is a antibiotic having β-lactum thiazolidine ring.
Penicillin G is the starting material for 6-amino penicillanic acid which is the key intermediate in the production of wide range of semi synthetic penicillins.
Mold used for the production of penicillin is Penicillium chrysogenum
Penicillin is a antibiotic having β-lactum thiazolidine ring.
Penicillin G is the starting material for 6-amino penicillanic acid which is the key intermediate in the production of wide range of semi synthetic penicillins.
Mold used for the production of penicillin is Penicillium chrysogenum
types of fermentation
Basically ,there are two methods of preparation of penicillin by fermentation:
Surface Culture Method:
In this method mold is grown on the surface of shallow layers of the fermentation medium.
Submerged Culture Method:
In this method mold is grown submerged in the fermentation medium.
master stock culture
It can be preserved by
Freeze drying
Fixing on soil sand mixtures
Storage under liquid nitrogen
Second method is the best method
The fermentation industry is composed of five major bio-ingredient categories.
They are:
- Proteins & amino acids.
- Organic acids.
- Antibiotics.
- Enzymes.
- Vitamins & hormones.
Optimum balance of the media is mandatory for cells propagation and for the maximum production of target metabolite (end-product).
Fermentation media
Media compositions:
- Carbon source.
- Nitrogen source.
- Minerals.
- Growth factors.
- Precursors (mutants).
Types of fermentation
Solid State fermentation (SSF).
Liquid State fermentation (LSF) Surface culture & submerged culture
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
2. CONTENTS
Definition of drying
Importance of drying
Difference between drying and evaporation
Equipments
References
2
3. DRYING
Drying is defined as removal of the liquid from a material by
application of heat & is accomplished by transfer of a liquid
from the surface into an unsaturated vapor phase .
Drying is the final removal of water from material (usually by
heat)
Drying is commonly the last stage in a manufacture process
Non-thermal drying
1- As Squeezing wetted sponge
2- Adsorption by desiccant (desiccation)
3- Extraction.
3
4. Difference between drying and
evaporation
Sl. No. Drying Evaporation
1. In drying processes, the main operation
usually carried out on solid materials, e.g.
powders, or products
In evaporation processes, the main
operation usually carried out on
liquid materials, e.g. solution, or
products
2. Drying in most of the cases means the
removal of relatively small amounts of
water from solids
Evaporation include the
removal of large amounts of
water from solutions.
3. In most cases, drying involves the
removal of water at temperatures
below its boiling point
Whereas evaporation means the
removal of water by boiling a
solution.
4. In drying , water is usually removed
by circulating air over the material in
order to carry away the water vapour
While in evaporation , water is
removed from the material as
pure water vapour mixed with
other gases. 4
5. Preservation of drug products
Preparation of bulk drugs
Improved handling
Improved characteristics
Applications….
5
6. Preservation of
drug products….
6
• Drying is necessary in order
to avoid deterioration. A
few examples are…
• --blood products, tissues…
undergo microbial growth
• --effervescent tablets,
synthetic & semi synthetic
drugs undergo…. chemical
decomposition.
7. Preparation of
Bulk Drugs….
7
• Drying is the final stage
of processing . Eg:
• *dried aluminium
hydroxide
• *spray dried lactose
• *powdered extracts (in
fig..chamomile
powder), e.t.c
8. Improved characteristics…
Drying produces materials of spherical shape,
uniform size, free flowing & enhanced
solubility. Some specific areas of imp are…
1. Granules are dried to improve the fluidity
& compression characteristics. These are
essential for production of tablets and
capsules.
2. Viscous & sticky materials are not free
flowing. Drying modifies these characteristics
8
9. IMPROVED
HANDLING….
Removal of moisture makes the material light in weight and reduces bulk.
Thus cost of transportation will be less & storage will be efficient.
If moisture is present, size reduction of drugs is difficult.
Drying reduces the moisture content.
9
11. It is the amount of water (moisture) held by the material that
exerts an equilibrium vapour pressure equal to that of pure
water at the same pressure.
Bound water (moisture)
It is the minimum water(moisture) held by the material that
exerts an equilibrium vapour pressure less than the pure water
at the same temperature.
11
12. Hygroscopic
materials
Water in:
-fine cpillaries
-Cell and fibre walls
-Physical interaction
Bound
water
Vapour pressure of
wet solids is less
than the v.p of pure
water
Non-Hygroscopic
materials
Water in void spaces
UnBound
water
Vapour pressure of
wet solids is equal to
v.p of pure water
12
15. Drum Dryer (Film Drying)
It consists of a drum of about 0.75-1.5
m in diameter and 2-4 m in length,
heated internally, usually by steam and
rotated on its longitudinal axis.
Working: The liquid is applied to the
surface and spread to a film, this may be
done in various ways, but the simplest
method is that shown in the diagram,
where the drum dips into a feed pan.
Drying rate is controlled by using a
suitable speed of rotation and the drum
temperature. The product is scraped
from the surface of the drum by means
of a doctor knife.
15
16. Uses
It is used for drying solution, slurries, suspensions etc and also the dry
products like this
• Milk products
• Starch products
• Ferrous salts
• Suspension of zinc oxide & kaolin
• Yeast
• Pigments
• Antibiotics
16
17. Adantages
Drying time is less, only in few seconds.
Drum dryer occupies less space
Product are obtained is completely dried and it’s final form
Rate of heat & mass transfer is high
Disadvantages
• Maintenance cost is higher
• Skilled operators are essential to control feed rate
• Not suitable for solution of salts with less solubility
17
19. Spray Dryer
Working : Drying of the material in spray dryer involves 3 steps
(1) Atomization of the liquid
(2) Drying of the liquid droplets
(3) Recovery of the dried product
The spray dryer provides a large surface area for heat and mass transfer by
atomizing the liquid to small droplets.
These are sprayed into a stream of hot air, so that each droplet dries to a solid
particle.
The drying chamber resembles the cyclone ensuring good circulation of air, to
facilitate heat and mass transfer, and that dried particles are separated by the
centrifugal action.
Spray dryer can be operated efficiently at various feed rates.
19
20. Uses
Product obtained are better than other dryer
Product quantity to be dried is large
20
It is continuous process & dried completely 3 to 30 sec.
Labor cost is low
Product of uniform & controllable size is obtained
Products shows excellent solubility
Suitable for drying of sterile products
Disadvantages
It is bulky and expensive
Huge equipment not always easy to operate
Thermal efficiency is low
Advantages
22. Tray dryer
Air flows in direction of the arrows over each shelf in turn.
The wet material is spread on shallow trays resting on the shelves.
Electrical elements or steam-heated pipes are positioned as shown, so that the air is
periodically reheated after it has cooled by passage over the wet material on one
shelf before it passes on the next.
22
24. Advantages
Handling of the material can be done without looses
Tray dryer is operated batch-wise
(a) Each batch of material are separate entity
(b) Equipment is readily adjusted for use in drying a wide
variety of material
Disadvantages
It require more labour to load and unload
24
26. Fluidized Bed Dryer
‘Fluidized’ means something that behaves like liquid.
In the fluidized bed dryer, the mixture of solids and
gas behave like a liquid and solid are called fluidized.
It provides good contact between hot air and particles
to obtain efficient drying.
The hot air is passed through a mesh, which supports
the conical vessel with a porous base.
This vessel is filled with powder to be dried.
26
27. Uses: It Is Popularly Used For The Drying of Granules
in the Production of Tablets.
Advantages :
Require less time for drying i.e., 20 to 40 min.
It is available in different sizes with the drying capacity 5 to 200 kg
Labour cost are low
Also used for mixing the ingredients
Hot spot are not observed in the dryer
Higher drying temp. can be used
27
28. Disadantages
Some powder are organic which develop electrostatic
charges to avoid this, efficient electrical earthing of the
dryer is essential.
28
30. Vacuum Dryer
This equipment is a good example of conduction
drier. The vacuum oven consists of a jacketed vessel
to withstand vacuum within the oven.
There are supports for the shelves giving a larger area
for conduction heat transfer. The oven can be closed
by a door.
The oven is connected through a condenser and liquid
receiver to a vacuum pump.
Operating pressure can be as low as 0.03-0.03 bar, at
which pressures water boils at 25-35 0C.
30
31. Advantages
It provides large surface area for heat transfer
Handling of the material, trays and equipment is easy
It is easy for switching over to the next material
Hot water of desired temp. can be supplied
Disadvantages:
It has a limited capacity
It is more expensive than tray dryer
31
33. Freeze Dryer
Freeze drying is a process used to dry extremely heat-
sensitive materials. It allows the drying , without
excessive damage, of proteins, blood products and
even microorganisms, which retain a small but
significant viability.
In this process the initial liquid solution or suspension
is frozen, the pressure above the frozen state is
reduced and the water removed by sublimation.
Thus a liquid-to-vapour transition takes place, but
here three states of matter involved: liquid to solid,
then solid to vapour.
33
