Drying. Drying is a mass transfer process consisting of the removal of water or another solvent by evaporation from a solid, semi-solid or liquid. ... In bioproducts like food, grains, and pharmaceuticals like vaccines, the solvent to be removed is almost invariably water.
About Aaron Equipment
Aaron Equipment Company is dedicated to one common goal, of providing the customer with quality equipment and dependable service at competitive prices. This has helpedAaron Equipment earnan international reputation as one of the world's leading dealers in the Process & Packaging Equipment Industry.
Aaron's inventory contains the largest selection of process equipment in the industry. As specialists in equipment procurement, Aaron advises its clients on the availability of equipment from single machines to large plants and processes. This equipment is available on an 'as is' basis, or the equipment can be reconditioned by Aaron’s skilled mechanics. In fact, they are so intent on ensuring customer satisfaction, most items can be inspected under power in one of their fully equipped warehouses
in this ppt i descussed about evaporator.evaporation,Evaporation is the process by which an element or compound transitions from its liquid state to its gaseous state below the temperature at which it boils.
types of Evaporators
Open kettle or pan
Horizontal tube natural circulation evaporator
Vertical tube natural circulation evaporator
Long tube vertical evaporator
Falling film evaporator
Forced circulation evaporator
Open-pan solar evaporator
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
Pharmaceutical Dryers. Dryers are used in a variety of industries, such as the food processing, pharmaceutical, paper, pollution control and agricultural sectors. ... Direct dryers convectively heat a product through direct contact with heated air, gas or a combusted gas product.
Drying. Drying is a mass transfer process consisting of the removal of water or another solvent by evaporation from a solid, semi-solid or liquid. ... In bioproducts like food, grains, and pharmaceuticals like vaccines, the solvent to be removed is almost invariably water.
About Aaron Equipment
Aaron Equipment Company is dedicated to one common goal, of providing the customer with quality equipment and dependable service at competitive prices. This has helpedAaron Equipment earnan international reputation as one of the world's leading dealers in the Process & Packaging Equipment Industry.
Aaron's inventory contains the largest selection of process equipment in the industry. As specialists in equipment procurement, Aaron advises its clients on the availability of equipment from single machines to large plants and processes. This equipment is available on an 'as is' basis, or the equipment can be reconditioned by Aaron’s skilled mechanics. In fact, they are so intent on ensuring customer satisfaction, most items can be inspected under power in one of their fully equipped warehouses
in this ppt i descussed about evaporator.evaporation,Evaporation is the process by which an element or compound transitions from its liquid state to its gaseous state below the temperature at which it boils.
types of Evaporators
Open kettle or pan
Horizontal tube natural circulation evaporator
Vertical tube natural circulation evaporator
Long tube vertical evaporator
Falling film evaporator
Forced circulation evaporator
Open-pan solar evaporator
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
Pharmaceutical Dryers. Dryers are used in a variety of industries, such as the food processing, pharmaceutical, paper, pollution control and agricultural sectors. ... Direct dryers convectively heat a product through direct contact with heated air, gas or a combusted gas product.
What is a Rapid Dryer, And How Does It Work? What is Its Purpose?VJInstruments
A rapid dryer (also known as a fbd fluid bed dryer) is a piece of process equipment that is widely used to decrease the moisture content of a variety of products such as food, pharmaceuticals, and chemical powders and granules, among others.
What is The Process, Structure and Working of a Rapid DryerVJInstruments
In the pharmaceutical industry, a Rapid Dryer (also known as a fluid bed dryer) is used extensively to decrease the moisture content of medicinal powder and granules.
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.
specifications and working of two stage spray drier with fluidized bed drier installed in experimental dairy,national dairy research institute,karnal,haryana
HOT NEW PRODUCT! BIG SALES FAST SHIPPING NOW FROM CHINA!! EU KU DB BK substit...GL Anaacs
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We specializes in exporting high quality Research chemical, medical intermediate, Pharmaceutical chemicals and so on. Products are exported to USA, Canada, France, Korea, Japan,Russia, Southeast Asia and other countries.
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
The prostate is an exocrine gland of the male mammalian reproductive system
It is a walnut-sized gland that forms part of the male reproductive system and is located in front of the rectum and just below the urinary bladder
Function is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semen
A healthy human prostate measures (4cm-vertical, by 3cm-horizontal, 2cm ant-post ).
It surrounds the urethra just below the urinary bladder. It has anterior, median, posterior and two lateral lobes
It’s work is regulated by androgens which are responsible for male sex characteristics
Generalised disease of the prostate due to hormonal derangement which leads to non malignant enlargement of the gland (increase in the number of epithelial cells and stromal tissue)to cause compression of the urethra leading to symptoms (LUTS
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
2. Objectives
At the end of this course, the student will be able to :
- Describe the different drying process in
manufacture of drug preparations.
- Identify the type and mechanism of dryer used for
drying process.
- Choose the method and equipment used for
drying process.
- Explain the advantage, disadvantage and used of
the process in pharmaceutical application.
2
3. Table content
• Introduction
• Evaporation method
• Types of dryer
• Factors affecting method and equipment
• Dryer for dilute solutions and suspensions
• Dryers for solid materials
3
4. - Drying is defined as a process in which the
liquid is removed from a material by the
application of heat and is accomplished by the
transfer of a liquid from a surface into an
unsaturated vapor phase.
- Objectives of drying :
• Eliminate all volatile liquid contained in non
volatile materials
• Get rid of water contained in solid materials
4
Introduction
5. - Drying is needed for the following purposes :
For the preparation of granules which can be
dispensed in bulk, compressed in the form of tablets
or filled in capsules.
For the preparation of certain products like dried
aluminium hydroxide, spray dried lactose and
powdered extracts.
For reducing the bulk and weight, thereby lowering
the cost of transportation and storage.
Vegetable drugs are dried before extraction to
facilitate grinding and to avoid deterioration on
storage.
As dried products are more stable than moist ones
therefore heat is required for drying. 5
6. Evaporation methods
• Hot air : discontinuous dryer, continuous
dryer.
• Infrared
• Under vacuum
• Drying in the presence of desiccants
• Cylinder drying
6
7. - Dryers for dilute solutions, suspensions :
Drum dryer
Spray dryer
- Dryers for damp solid materials :
Tray or shelf dryer
Tunnel dryer
Rotary dryer
Fluidised bed dryer
Vacuum dryer
Freeze dryer
7
Types of dryer
8. - Various methods and equipments for drying are available
the choice of which depends on the following factors :
Product is sensitive to heat or not.
Physical characteristics of the product before drying.
Nature of the solvent to be removed.
Process is to be carried out under aseptic conditions
or not.
Quantity of the product to be dried.
Available source of heat.
Cost involved.
8
Factors affecting method and
equipment
10. Dryer for dilute solutions and
suspensions
• The objective of these dryers is to spread the
liquid to a large surface area for heat and mass
transfer and to provide an effective means of
collecting the dry solid.
• Two main types are used :
- Spreading the liquid to a thin film
- Dispersing the liquid to a spray of small
droplets.
10
11. - Consists of a drum 0.75 to 1.5 m in diameter and 2-4 m in length,
heated internally, usually by steam, and rotated on its longitudinal
axis.
11
- The liquid to be dried is kept in a
feeding pan in which the heated
drum is applied to the surface and
spreads to a film which dries
rapidly.
- The dried product is scrapped from
the surface of the drum by means
of a doctor knife, in the form of
flakes.
- The drying rate can be controlled by adjusting rotation speed
and temperature of the drum (140-150oC, 6-30t/mn)
Drum dryer (Film dryer)
12. - Avantages :
The method gives rapid drying, the thin film spread over a large area
resulting in rapid heat and mass transfer.
The equipment is compact, occupying much less space than the spray dryer,
for example.
Heating time is short, being only a few seconds.
The drum can be enclosed in a vacuum jacket, enabling the temperature of
drying to be reduced.
The product is obtained in flake form, which is convenient for many
purposes.
- Disadvantage is that operating conditions are critical and it is necessary to
impose careful control on :
feed rate,
film thickness,
speed of rotation and
temperature of drum. 12
Drum dryer (Film dryer)
13. • Uses :
It can handle a variety of materials, either
as solutions or suspensions, substances
that are dried by this method include :
- milk products,
- starch products,
- ferrous salts, and
- suspensions of kaolin or zinc oxide.
13
Drum dryer (Film dryer)
14. - 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 disc of the atomizer is driven
by an air turbine and spins at
35000 rpm.
- Air is introduced with the help of
fan, which is heated by means of
electric heater to a maximum
temperature of 350oC. 14
Spray dryer
15. • Advantages :
Droplets are small, giving a large surface area for heat
and mass transfer, so that evaporation is very rapid.
Because evaporation is very rapid, the droplets do not
attain a high temperature.
Characteristic particle form gives the product a high
bulk density and, in turn, ready solubility.
Powder will have a uniform and controllable particle
size.
Product is free-flowing, with almost spherical
particles, and is especially convenient for tablet
manufactures.
15
Spray dryer
16. • Disadvantages :
The equipment is very bulky (15 m in height and 6 m
in diameter) and with the ancillary equipment (fans,
heaters, separations, etc.) is expensive.
16
Spray dryer
17. • Uses :
The substances that are spray dried
include :
- borax, citric acid, hexamine, sodium
phosphate, gelatin, acacia and
extracts,
- starch barium sulphate and calcium
phosphate, milk, soap and detergents.
17
Spray dryer
19. Tray or shelf or compartment dryers
- Is a cabinet with a heater, usually at
the bottom to assist convection, but it
is of limited value, giving virtually no
control of heat transfer or humidity.
The situation can be improved by
including a fan, so that forced
convection takes place, with increased
heat transfer and reduced local vapor
concentrations, but control is still
inadequate.
- Uses of the compartment dryer are
very varied because of the versatility
of the method, and include the drying
of crude drugs, chemicals, powders,
tablet granules, or items of
equipment. 19
20. - The drying method resembles the compartment dryer,
but takes the form of a long tunnel, with heated air
entering at one end and some means of moving the
material to be dried at the opposite end.
- As compared to the tray dryers, the tunnel dryer has
the advantage that it is semi-continuous or continuous
in operation, applications are similar, but more suitable
for large-scale production.
20
Tunnel dryers
21. - Is a modified form of the tunnel dryer in which the
particles are passed through a rotating cylinder,
counter-current to a stream of heated air. Due to the
rotation of the cylinder, the material is turned over
and drying takes place from individual particles and
not from a static bed.
- The rotary dryer is used for continuous drying on a
large-scale of any powdered or granular solid.
21
Rotary dryer
22. - This technique is very efficient and is used for drying granular
solids. With these types of dryers materials ranging from 5kg
to 200kg can be dried in about 20-40min.
- It consists of stainless steel chamber with a perforated
bottom, into which the wet material to be dried is placed.
For loading and unloading the drying chamber is removed
from the unit. The air is introduced from below which is
heated by means of heaters fitted therein, filtered and then
passes through the powder bed by means of induction fan
fitted in the upper part of the apparatus. The air is heated to
the required temperature and its flow rate is adjusted.
22
Fluidised Bed Dryer
24. - Advantages :
The material can be dried within 20-40 min
compared with several hour in tray dryers.
Drying takes place from individual particles and not
from whole bed.
Temperature of a fluidised bed is uniform and can
be controlled to the desired temperature.
A free flowing product is produced.
Since the containers are mobile which make
handling easy thereby labor costs are reduced.
Due to short drying time the unit has a high output.
24
Fluidised Bed Dryer
25. • Disadvantages :
Due to turbulence of the fluidised state, large
quantities of fines are produced but the use of
suitable binders during granulation can
overcome this defect.
Too wet granules stick together on drying
therefore too wet granules must not be used.
Many organic powders develop electrostatic
charges during fluidisation so efficient
electrical earthing of the drying chamber and
the cloth filters is necessary.
25
Fluidised Bed Dryer
26. - Is a modified form of vacuum still and consists of a jacketed
vessel sufficiently hard in construction to withstand vacuum
within the oven and steam pressure in the jacket. The oven is
connected through a condenser and receiver to a vacuum pump,
the vacuum pump can be connected directly to the oven. For
drying the material is spread on trays which are placed on steam
heated shelves in the jacket of vacuum oven.
26
Steam or
Water Jacket
Condenser
To Vacuum Pump
Receiver
Vacuum dryer (Vacuum oven)
27. - Advantages :
Thermolabile substances can be dried at a low
temperature and chances of oxidation are
reduced.
During the manufacture of a dry extract, a
porous and friable product is obtained which
is especially useful in tablet manufacturing.
By the use of condenser the solvent can be
recovered from the product.
27
Vacuum dryer (Vacuum oven)
28. - Disadvantages :
Heat transfer may be low and non uniform.
Capacity of vacuum oven is limited therefore may
not be suitable for large quantities.
Labor and running costs are high.
After drying a grinding process is necessary to get
a powdered product.
There is danger that the finally powdered
material may be drawn off by the vacuum pump,
and filters which require frequent cleaning have
to be provided.
28
Vacuum dryer (Vacuum oven)
29. Infrared drying
• The most effective wavelengths are of 10000
and 12000Ao, is the caloric effects of infrared
radiation that are used.
• The heat energy is directly transferred from the
infrared source to the product to be heated
without the need of an intermediate such as air
or water. All materials will absorb, reflect
and allow a fraction of the infrared spectrum to
pass through.
29
30. Infrared drying
• It is important to select the infrared emitters with the suitable
spectra according to the product to have an optimized
absorption of the radiation that will be subsequently
converted into heat and the product should be distribute in
the thin film to be dry. The lamps used are tungsten filament
lamps , are placed approximately 30cm of the product to dry
out. Drying can be done on trays or in a tunnel on an endless
belt .
30
31. Drying in the presence of desiccants
• Drying in the presence of desiccants is performed generally
under vacuum at room temperature where the vapor is
captured by a chemical bonding of water molecules : a
desiccant.
• A desiccant is a substance that absorbs water. It is most
commonly used to remove humidity that would normally
degrade or even destroy products sensitive to moisture.
31
32. Drying in the presence of desiccants
32
• This table shows that P2O5 is the best desiccant, it deprives the
atmosphere almost completely moisture . Most used for drying are P2O5
and H2SO4 pure. The others are mainly used to prevent rehydration
products stored in a closed container or a packaging container . Anyway,
the absorption capacity of these desiccant is very limited. They can only be
used for drying or dehydrating a little substance rich in water.
Residual water in mg per liter of water
Calcium Chloride ……………………………
Potassium hydroxide ……………………..
H2SO4 95% …………………………………….
Silicagel ………………………………………….
Potassium hydroxide ……………………..
Calcium Sulfate ………………………………
H2SO4 pure …………………………………….
Phosphorus pentoxide (P2O5)………….
1,5
0,8
0,3
0,03
0,014
0,005
0,003
0,00002
33. - Freeze drying (Lyophilisation or Cryodessication ) Is the process in which
water is removed from liquid product by sublimation hence this process
is also known as sublimation drying.
- The frozen water in the material is vaporized directly from the solid
phase to the gas phase without intermediate passing through the liquid
state .
- The sublimation is obtained industrially under a vacuum of 0.10 mm Hg
with a corresponding vaporization temperature of -40oC.
- Usually, the normal pressure 760mmHg at temperature below 0OC, the
water is in solid form (ice) but it is in liquid form at 100OC which it
passes as vapor at this temperature. For a pressure 4,58mmHg at
0,0076oC, the three phases are in equilibrium, it is the triple point.
- The diagram show that it is possible to change directly of the substance
from solid to vapor by making a small changes in pressure and
temperature. 33
Freeze drying
34. Freeze drying
In thermodynamics, the triple point of a substance is the temperature and
pressure at which the three phases (gaz, liquid, and solid) of that substance
coexist in thermodynamic equilibrium.
Ex : Triple point of water is at 4.58mmHg-0.0076oC.
34
35. Freeze drying
A freeze dryer comprises two chambers connected to
each other, the chamber A (sublimation or evaporator) is
cooled to a temperature which allows the freezing of the
product to dry, for example -40oC. At this temperature,
the sublimation of the ice is achieved in a pressure in the
chamber is less than or equal to 0,1mmHg, which is
achieved through a vacuum pump. In chamber B
(condenser) refrigerant system of the freeze dryer allows
to be at a lower temperature, for example -50 ° C, this
temperature allows the saturation vapor pressure,
obtained in A, to be reduced in B. This imbalance permits
movement of the steam from A to B,.
35
37. • Uses :
- Freeze drying is used for the manufacture of
certain pharmaceutical and biological
products which are thermolabile.
- It is also used for drying :
Blood plasma
Vitamins
Enzymes
Hormones
Antibiotics.
37
Freeze drying
38. References
1. Introduction to pharmaceutics-1. Ashok
K.Gupta. 3rd edition. 1991.
2. A. LEHIR -Pharmacie Galénique, bonnes
pratiques de fabrication des médicaments.
Masson. Paris. 8ème édition 2001.
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