IMPROVED INCINERATOR
DESIGN FOR HANDLING
MEDICAL WASTE
GROUP 7
Chifuniro Matope, Dominic Mapanje, John Kabambe.
SUPERVISOR.
Dr. Uluko.
INTRODUCTION
• 10 -25% of hospital waste is toxic and harmful and requires
special handling. (International Committee for Red Cross ;
Medical Waste Management)
• Medical waste incineration (MWI) is the dry oxidation process
that reduces organic and combustible waste to inorganic,
incombustible matter at temperatures between 600-12000C,
resulting in a significant decrease in overall waste volume
(Incineration o f Healthcare Waste and the Stockholm
Convention Guidelines, p. 9).
PROBLEM STATEMENT
• Incinerators emit harmful and toxic substances i.e., dioxins and
furans, particulate matter, acid gases and heavy metals. They
cause birth defects, reproductive effects, serious respiratory
problems and they have great impacts on the immune system.
• There is high emission levels of black smoke. This creates
discomfort for people working around the incinerators.
OBJECTIVES
Main objective
To design an incinerator with an improved air pollution control system
suitable for exhaust gas cleaning in medical waste incinerators to improve air
quality.
Specific objectives
 To reduce concentrations of harmful flue gas.
 To minimize black smoke emissions by reducing the number of particles in
the smoke emissions.
 To test the incinerator to ascertain its performance with regard to black
smoke emission reduction and air quality improvement.
LITERATURE REVIEW
Medical waste management
Methods
• Recycling
• Dumping in landfills
• Incineration - Incineration converts waste into ash, flue gas and heat. Incineration is
preferred since it is able to reduce the solid mass of the original waste material by 80% 85% and the volume by 95% - 96%
• Has a significant benefit in treatment of hazardous clinical waste where pathogens and
toxins can be destroyed by high temperatures
INCINERATORS
• Several types and sizes of incinerators used depending on the volume
of waste material and the type of waste materials
• Moving Grate Incinerators
• Fixed Grate Incinerators
• Rotatory kiln incinerators
• Liquid injection Incinerators
• Controlled air incinerators
INCINERATOR’S FLUE GAS AND ITS COMPOSITION
• Particulate matter
• Heavy metals
• Acid gases
• Carbon monoxide
• Organic compounds
EFFECTS OF THE ABOVE COMPONENTS OF FLUE GAS
• Particulate matter - Long-term exposure = heart disease, decreased lung function,
increased respiratory symptoms such as coughing
• Polycyclic aromatic hydrocarbons - linked to increased risk of cancer, blood and liver
abnormalities (long-term inhalation of PAH vapor)
• Acid gases - can damage eyes and mucous membranes along with the respiratory
system
• Dioxins and furans - most-hazardous organic products of incomplete combustion;
skin toxicity causing skin lesions, immunotoxicity and neurotoxicity, teratogenicity,
endocrine disruption and predisposition to cancer
CURRENT WAYS OF AIR POLLUTION CONTROL IN
INCINERATORS
• Cyclone Separators
• Gas conditioner systems
• Baghouses (fabric filters)
• Wet scrubbers
• Mist eliminators
PROBLEMS WITH CURRENT TECHNOLOGY
•
Wet scrubbers: They are prone to severe corrosion and require frequent
maintenance.
•
Fabric filters: The fabric life is shorted due to high temperatures, and they
burn and melt at high temperatures
•
Cyclone Separators: Low efficiencies for small particles, they are unable to
process sticky materials and have high operating costs due to pressure drop.
•
Mist eliminators: Major problem of this technology is plugging, which is the
blockage due to substance build up on the surface of the mist eliminator.
WHAT’S LACKING ?
• Malawi incinerators hospitals do not have incinerators with air
pollution control systems
PROPOSED SOLUTION.
•
•
We are going to design an incinerator with an improved APCE.
The direction we will take in coming up with a solution is to
improve on the already existing technologies by analysing their
drawbacks and evaluating which areas we can modify, or combine
their operation with other technologies.
•
To come up with a more effective way of purifying the smoke that it
released from the incinerators.
PRODUCT DESIGN SPECIFICATION (PDS)
DESIGN SPECIFICATION
DETAILS
Low Cost
should not exceed K100,000.
Size
diameter between 90mm and 140mm to fit the size of the
chimney of the incinerator.
Reliability
Maximum of 3% failure rate over service life.
Expected Product Safety
Should not have sharp projections.
Should not be toxic to the user and the environment.
Should not be corrosive or flammable.
Efficiency
purify exhaust gas at a faster rate, at least matching the rate of
gas exhaustion.
Disposal
disposed after 1 years of operation.
Shelf life
expected to be two years from date of manufacture.
DESIGN SPECIFICATION
DETAILS
Life in service
expected to be run for a year with nominal
maintenance before becoming completely inoperable.
Materials
Light-weight
transportable
not easily damaged by impact.
Maintenance
minimal maintenance, easily be performed by the
operator
Standards
comply with the medium US EPA emission limits,
especially for the dioxins/furans.
Expected product service environment.
The operating temperature is 200°C - 1000°C
The product will be exposed to dirt or other
contaminants.
Testing
Prototypes to be proven to meet International
Organisation for standards.
MATERIALS AND METHODS
Data collection
• The data that will be collected for the implementation of this device
will be both qualitative and quantitative
• The qualitative data will be collected from surveys that will be
generated
• Quantitative data will be collected from the different ways of
measuring and quantifying smoke.
• smoke photometers
• gas chromatograph connected to a mass spectrometer or GCMS.
Data Analysis
• The survey will have a Likert scale that is more effective to use.
• The rest of the data, gathered from tests, will be analysed using
statistics software, i.e. R Studio, SPSS.
• This will also develop relationships that indicate whether its
effective and successful.
Materials
The materials that will be needed in the course of this design include;
 A smoke photometer
 Gas chromatograph
 Mass spectrometer
 Glass Jars
 An incinerator.
EXPECTED RESULTS
• To have an incinerator design with an air pollution control
equipment suitable for cleaning of smoke in medical waste
incinerators before it is released into the atmosphere to improve
air quality.
• The concentrations of
toxins when measured
should fall under the ranges
recommended by the WHO.
• The color of smoke should be clear by removing
smoke particles to have a reduced emission of black
smoke.
• The APCE should be simple and it should efficiently
clean the gas exhaust from the MWI.
• The equipment designed should be able to undergo
testing to prove that it is successful in reducing the
particles in smoke that lead to air pollution
DISCUSSION
• An incinerator with improved APCE prototype is
going to be produced.
• It will be able to change the colour of black smoke
and improve air quality
• The laboratory tests that will be conducted during
the prototype design will help ensure that the
prototype produces the desired results.
CONCLUSION
• Handling of medical waste remains a major problem in many
hospitals.
• Incinerators emit smoke containing flue gases that cause air
pollution.
• The aim of this project report is to develop an incinerator with a
an APCE that is durable, efficient and low cost.
• To improve air quality by reducing content of flue gases and also
changing the colour of smoke.
THANK YOU