UNIVERSITY
INSTITUTE OF ENGINEERING
ENGINEERING CAMPUS
A Project Proposal on Sonic Fire Extinguisher
Prepared By:
SUBMITTED TO:
DEPARTMENT OF INDUSTRIAL ENGINEERING
KATHMANDU, NEPAL
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ABSTRACT
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TABLE OF CONTENTS
CHAPTER ONE: INTRODUCTION.......................................................................................................... 5
1.1 BACKGROUND .................................................................................................................................... 5
1.2 STATEMENT OF PURPOSE ..................................................................................................................... 5
1.3 OBJECTIVES ....................................................................................................................................... 5
1.3.1 General Objective ............................................................................................................. 5
1.3.2 Specific Objective .............................................................................................................. 5
CHAPTER TWO: LITERATURE REVIEW ................................................................................................. 6
2.1 FIRE ................................................................................................................................................. 6
2.2 SOUND WAVES .................................................................................................................................. 7
2.3 CONVENTIONAL FIRE EXTINGUISHER ....................................................................................................... 8
2.4 USE OF SOUND WAVES AS FIRE EXTINGUISHER ......................................................................................... 8
2.5 FINDING HOLES .................................................................................................................................. 9
2.6 LOOKING FOR DEBATES ........................................................................................................................ 9
CHAPTER THREE: METHODOLOGY .................................................................................................... 10
3.1 COST ESTIMATION ............................................................................................................................ 11
3.2 TIME SCHEDULE................................................................................................................................ 12
CHAPTER FOUR: TECHNICAL DISCUSSION ......................................................................................... 13
4.1 PRINCIPLE........................................................................................................................................ 13
4.2 THEORY .......................................................................................................................................... 13
4.3 DESIGN ........................................................................................................................................... 15
CHAPTER FIVE: STATEMENT OF LIMITATION .................................................................................... 17
CHAPTER SIX: CONCLUSION ............................................................................................................. 18
REFERENCES ..................................................................................................................................... 19
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TABLE OF FIGURES
Figure a: Fire Tetrahedron ............................................................................................. 6
Figure b: Frequency range of sound wave ......................................................................... 7
Figure c: Time Schedule and Gantt chart .................................................................... 12
Figure d: Chip .............................................................................................................. 13
Figure e: Amplifier ...................................................................................................... 14
Figure f: Speaker .......................................................................................................... 14
Figure g: 555 Timer IC ................................................................................................ 15
Figure h: Collimator in 3D view .................................................................................. 16
Figure i: Collimator as seen from different views ....................................................... 16
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CHAPTER ONE: INTRODUCTION
1.1 Background
The rate of accidents due to fire has been increasing day by day. Fire hazards lead
to the loss of life and property. Though there are lots of chemical based
extinguishers available they have their own limitations and are not able to do their
job efficiently. Sound on other hand has energy which can be utilized in
extinguishing the fire. Thus, we have decided to develop a device i.e. Sound fire
extinguished that will extinguish fire within few seconds.
1.2 Statement of Purpose
The common fire extinguishers which one can purchase in market are meant for a
specific purpose. For an instance: Fire extinguisher C is used for extinguishing
fires caused due to electric hazards such as short circuit and surges. So for an
industry to keep every possible fire extinguishers at their work place and to select
the right type of extinguisher during the hazards is a task of mess. To solve this
problem we are working on Sonic Fire extinguisher, which is a device that will
extinguish fires caused by electric surges or some chemicals or even due to
household cooking oils using a single device with a change in frequency of the
wave.
1.3 Objectives
1.3.1 General Objective
To develop an environmentally friendly and safe method to extinguish
fire using acoustic setup.
1.3.2 Specific Objective
To identify the frequency range that will be able to suppress an open
flame.
To analyze the physics of sound-flame interactions.
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CHAPTER TWO: LITERATURE REVIEW
2.1 Fire
Fire is the fast oxidation of a material in the exothermic chemical process of combustion
releasing light,heat,and different reaction products.Flame is the observable portion of the
fire.Fires start when a flammable or a combustible material, in combustible material,in
combination with an adequate quantity of an oxidizer for instance ,oxygen gas is exposed
to a source of heat or ambient temperature above the flash stage for the fuel/oxidizer mix,
and is able to withstand a rate of rapid oxidation and produces a chain reaction.This is
normally called a fire tetrahedron.
Figure a: Fire Tetrahedron
Fire cannot exist if deprived of all of these elements in place and in the right proportions.
There are four main classes of fire:
1.Class A:Class A fires are those fueled by materials that,when they burn, leave a residue in
the form of ash, such as cloth paper,rubber,wood, and certain plastics.
2.Class B:Class B fires involve flammable liquids and gases such as gasoline,Kitchen
grease,propane, and acetylene.
3.Class C:Class C fires involve energized electrical wiring or equipment(motors
,computers,panel boxes).
4.Class D:Flames in exotic metals such as magnesium, sodium,titanium, and certain
organometallic compounds are class D fires. (Scribd)
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2.2 Sound Waves
Sound is a form of energy,just like electricity, heat or light.The sound moves through a
medium by alternately contracting and expanding parts of the medium, it is travelling
through. This compression and expansion creates a minute pressure difference that we
percieve as a sound.
Sound is a vibration that propagates as a perceptible mechanical wave of pressure and
displacement,through a medium such as air and water and sound cannot travel through a
vacuum.The sound waves are generated by a sound source, such as the vibration
diaphragm of a speaker.The sound source creates vibration in the surrounding medium.
As the source continues to vibrate the medium, the vibrations propagate away from the
source at the speed of sound, thus forming the sound wave.
Figure b: Frequency range of sound wave
Sound waves are regularly streamlined to a description in terms of sinusoidal plane
waves, which are characterised by these common properties: frequency, wavelenght,
wave number,amplitude,sound pressure, sound intensity, speed of sound, and
direction.Sound that is perceptible by humans has frequencies from about 20 Hz to 20,000
Hz.In air at standard temperature and pressure ,the corresponding wavelenght range from
17m to 17mm. (BIET)
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2.3 Conventional Fire Extinguisher
There are four common techniquesused in extingusihing fires.Cooling down the burning
material is the most common practice used to extinguish fire.Secondly is through
excluding oxygen from fire.Asphyxiating agents are substances used to extinguish a fire
by cutting off the oxygen supply.Foam, which is the content of some of the fire
extinguishers, can help to cool down and isolate the fuel surface from the air, reducing
combustion and being able to resist wind and draught disruption.Foam should never be
used on the energized electrical euipment because it is electrical conductor.carbondioxide
is used in fire extinguishers and is being ideally used in electric equipment and
sand.Another method of extingusihing a fire is to remove the fuel supply by switching off
the electrical power, isolating the flow of flammable liquids or removing the solid
fuel,such as wood or textiles. (Wikipedia)
2.4 Use of Sound Waves as Fire Extinguisher
Sound wave was found to be one of the alternatives in creating new method in flame
extinguishing technology.The pressure fluctuations due to the sound wave propagation
will cause a significant change in temperature profile near the flame. High pressure to low
pressure and vice versa will cause immediate change on the temperature according to the
first law of thermodynamics. The combination actions of fluctuating temperature,
pressure and air-fuel ratio to the flame will affect the flame behaviour under the regulated
sound wave environment.Pressure perturbation is known to have influence on the burning
rate of material and cause combution instabilities, which could eventually lead to flame
extinction.(source: www.scribd.com)
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2.5 Finding Holes
Sound fire extinguishers are still not commercialized though it has been proved that sound
fire extinuishers can extinguish fires.Many reasons are behind this. some of the major
reasons are listed below:Still have lot of improvements to be made until sound fire
extinguisher be used to put out large or mid-scale fires such as forest fires.Needs to be
made of much lighter weight for the portabilityNeeds to reach a larger distance possibly
using Zoom-in technologyLot of improvements to be made through national or global
projects. (Arirang)
2.6 Looking for Debates
Fire extinguishers are trying to eradicate one of the elements in the pyramid in order to
eliminate the flame. Firefighting in an enclosed space has always been a problem, other
than the accessibility for the fire fighter to access the place, accessing the water, carbon
dioxide or other fire extinguisher technology to the closed space is a major challenge. A
compact independent and reliable fire extinguisher is required in order to overcome this
problem. So sound frie extinguisher can be one of the required new technology.”No mess
No smell” so sound waves are much cleaner.With many possible applications, firefighting
with sound is promising venue,in which sound pressure waves can be used to save an
important control centre, or an astronaut’s life. These are some of the opinions in favour
of sound fire extinguisher. But it has not been yet commercialized and made more
efficient. It is not supposed to extinguish mid-scale or large fires which questions its
applicability. (news; news)
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CHAPTER THREE: METHODOLOGY
Being a research based project, we conducted various methods to resolve our doubts
regarding various aspects of our project. We conducted both the primary and
secondary methods for our research. A detailed research was made by analyzing
experiments and research papers from previous researchers and by performing
interviews with the experts in the respective field.
There were two research papers that we went through for our project. One was
Research paper of the DARPA and the other paper was on the sonic fire extinguisher
by two engineering students. We also applied qualitative approach for our research.
We interviewed expert on this matter. We asked a series of questionnaires about our
doubts and confirmed the project to be feasible. We got idea on most of the project
parts through the research papers. Research papers explained clearly about the
experimental setup, the working phenomenon and its principle. We got a clear idea on
how the experiment is to be done what problems we can possibly come across. Those
papers really helped us a lot but, we still had many things we were unsure about
regarding equipments types and availability, feasibility of the project, the cost and
how the experiment is to be performed. We got our doubts cleared by interviewing
Mr. Surendra Mathema, Head of Power Tech in Patan Industrial Estate. He
answered to all our queries and provided us an insight on this project. He is also the
one, supplying us with the equipments and assisting us in our project. Hence, we
contained both the primary and secondary methods in our research.
Collecting data was quite hectic for our group. Since, this project isn’t
commercialized so we couldn’t obtain all the answers we were looking for. We had
fewer resources to look into and very little time for simulating the project for its
conformability. Still we have some unanswered queries regarding some of the parts
and their successful working. Though, the interview helped us quite a lot, we still
have some doubts which we will be solving through hit and trial method during the
project. Overall, we have gathered all the necessary information which is supposedly
sufficient for assuring this project’s feasibility, both in qualitative and functional
manner.
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3.1 Preliminary evaluation:
Evidence of importance:
Fire hazards are quite frequent and do lots of damage especially in industrial sectors.
Available fire extinguishers only work for certain type of fire and are not that efficient
in time .Thus, the device we have selected i.e sound fire extinguisher is a necessity
which can extinguish fire with minimal sources in matter of time.
3.2 Preliminary findings:
Sound fire extinguisher utilizes the basic theory of making sound and sound has a
tendency of dispersing, big sound and energy have to be created to extinguish the fire.
It has huge potential to reduce losses due to fire hazards. It is economic, reliable,
versatile and fast.
3.2 Cost Estimation
Material Specification Quantity Estimated cost(Rs.)
Frequency Generator 555 timer IC 1 1000
Amplifier Mono power 1 5000
amplifier, 100 watt
Speaker 100 watt, impedance 1 3000
4 ohm or 8 ohm, 12
inch diameter
Tentative Aluminum collimator 5000
and wires
total 14,000
The price has been kept by doing a thorough market research. Both local and global
market has been sourced for this data and preference has been given to local market,
so that the parts are easily accessible during the assembly of the Sonic Fire
Extinguisher. Though our cost estimation is NRs.14,000, we will be allocating
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NRs.25,000 for conditions of hazards that might destroy our parts later during its
formation.
3.2 Time Schedule
The time schedule has been prepared tentatively supposing our project starts in the
end of November. We have prepared a Gantt chart from the schedule.
Figure c: Time Schedule and Gantt chart
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CHAPTER FOUR: TECHNICAL DISCUSSION
4.1 Principle
Sound fire extinguisher is developed under the principle of quenching fire by
lowering its temperature with contacting vibration energy from low frequency sound
less than 100Hz to fire and blocking inflow of oxygen with sound wind. The device
concentrates a sound beam through special sound winds and increases sound energy
performance 10 times more4 to put out the fire .This is because it utilizes the basic
theory of making sound and sound has a tendency of dispersing ,big sound and energy
have to be created to extinguish the fire . That is even if 100 w is produced, it just
makes a big sound but only 1/10 can be utilized for putting out the fire. The special
sound wind has convex shape which concentrates all sound into one place to increase
its effectiveness by more than 10 times. As, a result the size of battery and amplifier
can be reduced in size and weight so as to make it more practical.
4.2 Theory
The parts of the sonic fire extinguisher are already known. A brief definition or
information of those parts are as follows:
4.2.1 Frequency Generator
A frequency generator, also known as a signal generator described as
electronic audio acoustics and equipment testing and setup, or informational
signals, commonly associated with a telephone system.
Frequency generator that we are going to use is 555 timer IC. It is an
integrated circuit (chip) used in a variety of timer, pulse generation and
oscillator applications. It is the most popular integrated circuit ever
manufactured due to its low price, ease of use and stability.
Figure d: Chip
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4.2.2 AMPLIFIER
Amplifier is an electronic device that can increase the power of a signal. It is a
two-port electronic circuit that uses electronic power from a power supply to
increase the amplitude of a signal applied to its input terminals, producing a
proportionally greater amplitude signal at its output.
We need a power mono amplifier of 100 watt. The mono amplifier produces a
single power signal which is ideally suited to the low frequency design of a
subwoofer. Because of its high electrical current resistance when power
demand increases, two subwoofers can be wired together to it.
Figure e: Amplifier
4.2.3 SPEAKER
We need speaker of 100 watt, having impedance 40 ohm or 8 ohm with 12
inch diameter.
Figure f: Speaker
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4.2.4 COLLIMATOR
Collimator is a device that narrows a beam of particles or waves. To narrow
can mean either to cause the direction of motion to become more aligned in a
specific direction or to cause the spatial cross section of beam to become
smaller.
We need an auto collimator made up of aluminum.
4.3 Design
Figure g: 555 Timer IC
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Figure h: Collimator in 3D view
The diameter of bigger hole which receives the sound from speaker of the collimator
will be in accordance with the diameter of speaker and the smaller hole which will
converge the sound will have a diameter which is (1/3) rd of the diameter of bigger
hole.
Figure i: Collimator as seen from different views
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CHAPTER FIVE: STATEMENT OF LIMITATION
Some limitations of our device will be as given below:
The weight of our device will be heavy as it will have all the components
inbuilt in a case.
The user should have read the operating manual of our device properly
before using this device as they should know which frequency will work best
on a particular class of fire
Inability of our Sonic Fire extinguisher to extinguish large fires is also one of
the limitation.
Can’t be used for wider range fire extinguishing operation but will be best for
short range action.
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CHAPTER SIX: CONCLUSION
We are still using classic methods to extinguish fire. What if we can imply sonic fire
extinguisher in our traditional alarm system so that when there is fire, the fire is
removed with the sound waves? Well this is just a fiction till now but the property of
sound wave to extinguish fire is a reality and our group is working to give this reality
a perfect figure.
There are some limitations in the devices which have been built till date, such as
heavy weight, uneasy handling and bigger size of the device and lack of immobility.
So focusing on these limitations our device shall be invented.
We believe that if this device can be commercialized later on, the use of chemicals for
the purpose of extinguishing fire will be reduced along with their exposure to
environment; hence our major objective i.e. to develop a safe and efficient method to
extinguish flame using acoustic energy has been fulfilled.
Moreover, we are working on extinguishing different types of flames using different
range of frequency which satisfies our next objective.
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References
Arirang. (n.d.). Arirang issues . Retrieved from www.youtube.com.
BIET. (n.d.). Development of Portable Fire Extinguisher using Acoustic. Retrieved
from
http://www.kscst.iisc.ernet.in/spp/40_series/39S_bestprojreports/39S_BE_197
7.pdf.
news, B. (n.d.). Retrieved from
http://www.kscst.iisc.ernet.in/spp/39_series/SPP39S/02_Exhibition_Projects/1
96_39S_BE_1977.pdf.
Scribd. (n.d.). Scribd. Retrieved from www.scribd.com.
Scribd. (n.d.). Scribd. Retrieved from
https://www.scribd.com/document/291330368/Study-of-Sound-Wave-as-a-
Flame-Extinguisher.
Wikipedia. (n.d.). Fire Extinguishing Methods. Retrieved from www.wikipedia.com.
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