2. INTRODUCTION
• Bio-Medical Waste from hospitals, nursing homes
includes infectious items e.g. amputated body
parts, body fluids, cultures of contagious viruses
and excreta from patients with high contagious
diseases are highly toxic and extremely harmful.
It also includes scalpels, needles, bandages and
other waste from operation theaters and
laboratories. The easiest way to dispose off
medical waste is through Bio-Medical
Incinerators. The treatment technology of
controlled air burning at high temperatures to
reduce the weight and volume of wastes is called
incineration. Three factors are most important for
the incineration process known as three T’s
namely:
TIME, TEMPARATURE, TURBULANCE
3. Biomedical Waste (BMW)
is…
• Bio medical waste generated during the
diagnosis, testing, treatment, research or
production of biological products for
humans or animals (WHO)
• WHO estimates
– 85% of hospital waste is non-hazardous
– 10% is infectious
– 5% is non-infectious but consists of hazardous
chemicals like methylchloride and formaldehyde.
4. INCINERATION PROCESS
• The Incinerator is double chambered and is designed on ‘’controlled air’’ incineration
principle with a minimum of 100% access air. Volatilisation of waste is achieved in
primary chamber through supply of air through various nozzles on all sides of the
primary chamber, this is done by the F. D Fan provided with the incinerator. Heat is
generated with fuel oil burner with auto operation system suitable negative draft is
maintained in primary chamber to avoid leakage of gaseous emission from it. The sides
of the top position of the chambers are rounded up to avoid possibility of formation of
dead zones.
• Waste is fed inside the primary chamber of the incinerator through an automatic
waste feeding system ensuring no direct exposure of the furnace temperature to the
operator.
• Volatilised/gasified matters from waste is taken to the secondary chamber with
residence time of minimum 1 second. The heat source in this secondary chamber is
auto controlled fuel oil secondary burner. After the gases leave the secondary chamber,
they enter the venturi scrubber where gases are treated with caustic and scrubbed. A
re-circulating pump of stainless steel construction is provided in the system for
circulation of caustic and water inside the scrubber. The re-circulation pump is common
for the scrubber and droplet separator. All the interconnecting piping is of stainless
steel. The gases finally enter the droplet separator wherein the moisture is removed
from the gases. This reduces the flue gas temperatures making it safe to be let out in
the atmosphere. An I.D. Fan is provided at the end to release the gases to a 30 mtrs
high stack.
5. • In the incineration process, the waste is thermally decomposed in the
primary chamber at a temperature of 800±500 C. The gaseous products
(volatile mater) are completely oxidised in the secondary chamber due to
sufficient residence time, high temperature (1050±500 C.) high turbulence
and 100% excess air. The flame port through which the gases pass from
primary chamber to secondary chamber is sized to produce high velocity for
excellent mixing of combustion air and gases.
• Both the chambers are fitted with burners to fire support fuel for initial
heating up of chambers to required temperatures as well as maintain
these temperatures.
WASTEPREPARATION PRIMARYCHAMBER SECONDARYCHAMBER
I.D.FAN DROPLETSEPARATOR VENTURISCRUBBER
CHIMNEY
6. PROCEDURE
First heated up both the chambers . Primary and secondary
chambers are heated up to 1000 degree C & 800 degree C
respectively
Now wastes are kept inside the primary chamber
Check he water level in the recirculation tank before
proceeding further . It should be full.
Close both charging and ash removal doors.
Switch ON the Automatic model on the PLC based control
panel
ON the F.D.FAN & I.D. FAN
7. The Secondary chamber Burner is now ‘’ON’’ .Primary Chamber
Burner is also ‘’ON’’ .
Burning of the B.M.W is kept continue for one hour.
Rake the waste after every 20 minutes.
After burning the ash particles precipited and the smoke comes
out through droplet separator, venture scrubber and released in
the environment through a 30 meter chimney
After the operation both the burners are OFF.
Water pump stops . both F.D FAN and I.D.FAN are kept on until
the temperature drops below 50 degree C in the both
chambers.
Now close the individual burners fuel oil valve , Switch OFF the
main supply to the control panel.
8. PROCESS FLOW DIAGRAM
PRIMARY CHAMBER
Burning of Waste
Temperature 800±50 deg. C.
SECONDARY CHAMBER
Flue gas incineration at a temperature of 1050
deg. C.
1 second residence time for flue gases
VENTURI SCRUBBER
High Pressure Air Pollution Device for neutralizing
of gases and controlling SPM.
DROPLET SEPARATOR
Removing the largest droplet present in the flue
gases.
I.D. FAN
Maintaining the negative draft and control the
gas flow in the incinerator.
CHIMNEY
Releasing the clean gases in the atmosphere
9. COMPONENTS
Main combustion chamber/Primary
chamber
This is fabricated out of mild steel , and is
refractory lined and
insulated from inside . This is equipped with
loading door, ash removal door and automatic
burner operated by temperature indicating
controller which is set at 800+-50 degree C.
Post Combustion Chamber/Secondary
Chamber
This is fabricated out of mild steel , and is
refractory lined similar to primary chamber. This
is equipped with secondary burner . A
temperature controller is provided which is
connected to the control panel . The operating
temperature is 1050+-50 degree C. Minimum 1
second residence time is provided for flue gases
in this chamber.
10. • Primary chamber burner
primary burner should be fully automatic
complete with ignition transformer, ignition
electrodes, necessary fuel lines, photo cell,
blower, fuel pump and fuel oil nozzle. The burner
operates automatically on the temperature set on
the digital temperature controller fixed on the
control panel.
• Secondary chamber burner
primary burner should be fully automatic
complete with ignition transformer, ignition
electrodes, necessary fuel lines, photo cell,
blower, fuel pump and fuel oil nozzle. The burner
operates automatically on the temperature set on
the digital temperature controller fixed on the
control panel. Fuel pressure indicator gauge is to
be provided for the burner.
11. • Electrical Control Panel
The control panel supplied along with
the Incinerator is outdoor type and
placed separately. All controls will be
housed within this common control
panel. The panel is duly powder
coated. It houses the primary and
secondary burner controls, all the
temperature controllers, motors
starters, isolator switches, overload
relays for burners and fans and audio
visual alarms for abnormal workings.
All electrical power, earth and control
cabling from the control panel to the
individual drives and components shall
be provided by us. The control panel is
pre-wired. However, external wiring is
to be carried out at site.
12. • High Pressure Venturi Scrubber
The venture scrubber shall have minimum
pressure drop of 350 mm WC to achieve the
prescribed emission limit. The flue gases from
the Cyclone separator are then sent to venturi
scrubber. Venturi scrubber is a high energy
device (fabricated out of stainless steel )
where particulate matter as well as acidic
pollutants are scrubbed. Here the acidic gases
are removed by absorption with caustic and
the particulates by the inertial impaction
energy. A high-pressure drop across the
venturi scrubber, imparts sufficiently high
energy which helps in atomising the
scrubbing liquid and thus trapping the
particulates. In venturi, gases saturate due to
evaporation of water vapour and thus cools.
5% caustic solution is used as scrubbing liquid
to neutralise the SO2 present in flue gases.
• Droplet Separator
The flue gases then enter tangentially into the
droplet separator, which is of cyclonic type. By
the action of centrifugal force, the larger
droplets present in flue gases settle down.
13. • Circulating Pump
A re-circulating pump should be provided ,
which is coupled to an electric motor.
• Recirculating Tank
Re-circulating tank of suitable capacity
shall be provided and integral with the
droplet separator.
• Interconnecting Piping
All interconnecting piping between
scrubber, droplet separator and re-
circulating tank shall be provided.
• I.D. FAN
The I.D. FAN shall be dynamically balanced
and shall have a pressure of 450 mm WC
with an impeller of SS-316 construction.
• F.D. FAN
A forced draft fan shall be provided to
supply air inside the both chambers.
14. • Fuel Oil Tank & Piping
Fuel oil tank of suitable capacity fabricated out
of mild steel shall be provided. The fuel tank
shall have all connections for supply, return,
drain and visual checking of the quantity of fuel
present in the tank. The fuel line should consists
of one main valve, one individual valve for each
burner.
• Chimney
Self supported chimney of 30 mtr height shall
be provided. It consists of port hole, ladder,
stack drain etc. It shall be provided with cage
ladder, gas sampling platform, gas sampling
nozzles, painting trolley, rain cowl, stack drain,
base plate and foundation bolts. Chimney shall
be connected to incinerator by an inter
connecting duct.
• Emergency Stack
An emergency stack to vent out the gases
incase of power failure shall l be provided. The
emergency stack height shall be as per site
requirement , usually this shall be 6 mtr high
from ground level.
18. TYPES OF BIOMEDICAL WASTES
WASTE CATEGORY TYPE OF WASTE
Category No. 1 Human Anatomical Waste
Category No. 2 Animal Waste
Category No. 3 Microbiology & Biotechnology Waste
Category No. 4 Waste Sharps
Category No. 5
Discarded Medicine and Cytotoxic
drugs
Category No. 6 Soiled Waste
Category No. 7 Solid Waste
Category No. 8 Liquid Waste
Category No. 9 Incineration Ash
Category No.10 Chemical Waste
19. TECHNIQUES
SEGREGATION :- to segregate the wastes.
Colour Coding Type of Container
Yellow Plastic Bag
Red
Disinfected
container/Plastic
bag
Blue/
White Translucent
Plastic Bag / punch
proof containers
Black Plastic Bag
20. Bio medical waste
management in India
Biomedical waste (management and handling) rule
1998, prescribed by The Ministry of Environment and
Forests, Govt of India, came into force on 20th July
1998.
This rule applies to those who generate, collect,
receive, store, dispose, treat or handle bio medical
waste in any manner.
Thus bio medical waste should be segregated into
containers/bags at the point of generation of waste.
Thus Colour Coding & type of containers used for
disposal of waste is came into existence which is
shown as follows.
21. Environmental Legislation
The Environment (Protection) Act, 1986
The Biomedical Waste (Management & Handling)
Rules, 1998
The Municipal Solid Waste (Management & Handling)
Rules, 2000
The Hazardous Waste (Management & Handling)
Rules, 1989
The National Environmental Tribunal Act, 1995
The Air (Prevention and Control of Pollution) Act,
1981
22. Conclusion
• The bio medical waste generated from the
hospitals and other source will be treated
without polluting the environment.
• All the disposal process is done with in the norms
of CPCB and guidelines.
• The remaining material after incineration is safely
disposed according to the CPCB guidelines.
• Incineration of bio medical waste is one of the
techno-economical viable scheme which have
many advantages such as significant volume
reduction, weight reduction & also ability to
manage most types of wastes with little
processing before treatment.
