Fire fighting systems

Submitted by: Irfan shafique-31

hafiz saqib-10

Contents Fire history General information about fire Fire fighting equipment(extinguishers) Fire safety(alarms and sprinkle system

etc.) Technology in fire fighting(fire fighting

robots) Safety cautions

FIRE Definition Fire is a process in which substances

combine chemically with oxygen from the air and typically give out bright light, heat, and smoke; combustion or burning.

Fire triangle The fire triangle or

combustion triangle is a simple model for understanding the necessary ingredients for most fires. The triangle illustrates the three elements a fire needs to ignite: heat, fuel, and an oxidizing agent (usually oxygen).

Types of fire The main three types of fire have been coded with

either a letter or a standard pictogram shown to the right. Class A: Fires with trash, wood, paper or other combustible materials as the fuel source. Class

B: Fires with flammable or combustible liquids as the fuel source.

Class C:  Fires involving electrical equipment. Class D:  Fires with certain ignitable metals as

a fuel source. Class K Class K fires are fires in cooking oils and

greases such as animals fats and vegetable fats.

Stages of fire   These stages are incipient, growth, fully

developed, and decay.

Incipient – This first stage begins when heat, oxygen and a fuel source combine and have a chemical reaction resulting in fire.  This is also known as “ignition” and is usually represented by a very small fire which often (and hopefully) goes out on its own, before the following stages are reached.

Growth stage Growth – The growth stage is where the

structures fire load and oxygen are used as fuel for the fire. There are numerous factors affecting the growth stage including where the fire started, what combustibles are near it, ceiling height and the potential for “thermal layering”.  It is during this shortest of the 4 stages when a deadly “flashover” can occur; potentially trapping, injuring or killing firefighters.

Pictorial explanation

Fully Developed  – When the growth stage has reached

its max and all combustible materials have been ignited, a fire is considered fully developed.  This is the hottest phase of a fire and the most dangerous for anybody trapped within.

Decay Decay – Usually the longest stage of a

fire, the decay stage is characterized a significant decrease in oxygen or fuel, putting an end to the fire.  Two common dangers during this stage are first – the existence of non-flaming combustibles, which can potentially start a new fire if not fully extinguished.  Second, there is the danger of a backdraft when oxygen is reintroduced to a volatile, confined space.

Fire fighting equipment(extinguishers)

A fire extinguisher, or extinguisher, is an active fire protection device used to extinguish or control small fires, often in emergency situations.

Types of extinguishers Water and Foam

Water and Foam fire extinguishers extinguish the fire by taking away the heat element of the fire triangle. Foam agents also separate the oxygen element from the other elements.

Water extinguishers are for Class A fires only - they should not be used on Class B or C fires. The discharge stream could spread the flammable liquid in a Class B fire or could create a shock hazard on a Class C fire.

Carbon Dioxide

Carbon Dioxide fire extinguishers extinguish fire by taking away the oxygen element of the fire triangle and also be removing the heat with a very cold discharge.

Carbon dioxide can be used on Class B & C fires. They are usually ineffective on Class A fires.

Dry Chemical

Dry Chemical fire extinguishers extinguish the fire primarily by interrupting the chemical reaction of the fire triangle.

Today's most widely used type of fire extinguisher is the multipurpose dry chemical that is effective on Class A, B, and C fires. This agent also works by creating a barrier between the oxygen element and the fuel element on Class A fires.

Ordinary dry chemical is for Class B & C fires only. It is important to use the correct extinguisher for the type of fuel! Using the incorrect agent can allow the fire to re-ignite after apparently being extinguished successfully.

Wet Chemical

Wet Chemical is a new agent that extinguishes the fire by removing the heat of the fire triangle and prevents re-ignition by creating a barrier between the oxygen and fuel elements.

Wet chemical of Class K extinguishers were developed for modern, high efficiency deep fat fryers in commercial cooking operations. Some may also be used on Class A fires in commercial kitchens.

Clean Agent

Halogenated or Clean Agent extinguishers include the halon agents as well as the newer and less ozone depleting halocarbon agents. They extinguish the fire by interrupting the chemical reaction of the fire triangle.

Clean agent extinguishers are primarily for Class B & C fires. Some larger clean agent extinguishers can be used on Class A, B, and C fires.

Dry Powder

Dry Powder extinguishers are similar to dry chemical except that they extinguish the fire by separating the fuel from the oxygen element or by removing the heat element of the fire triangle.

However, dry powder extinguishers are for Class D or combustible metal fires, only. They are ineffective on all other classes of fires.

Water Mist

Water Mist extinguishers are a recent development that extinguish the fire by taking away the heatelement of the fire triangle. They are an alternative to the clean agent extinguishers where contamination is a concern.

Water mist extinguishers are primarily for Class A fires, although they are safe for use on Class C fires as well.

Cartridge Operated Dry Chemical

Cartridge Operated Dry Chemical fire extinguishers extinguish the fire primarily by interrupting the chemical reaction of the fire triangle.

Like the stored pressure dry chemical extinguishers, the multipurpose dry chemical is effective on Class A, B, and C fires. This agent also works by creating a barrier between the oxygen element and the fuel element on Class A fires.

Ordinary dry chemical is for Class B & C fires only. It is important to use the correct extinguisher for the type of fuel! Using the incorrect agent can allow the fire to re-ignite after apparently being extinguished successfully.

The Rules for Fighting Fires

Just remember the three A's ACTIVATE the building alarm system or notify the fire

department by calling 911. Or, have someone else do this for you.

ASSIST any persons in immediate danger, or those incapable on their own, to exit the building, without risk to yourself.

Only after these two are completed should you ATTEMPT to extinguish the fire.

Only fight a fire if: The fire is small and contained You are safe from toxic smoke You have a means of escape Your instincts tell you it's OK

Fire Extinguisher Use It is important to know the locations and the types of extinguishers in

your workplace prior to actually using one. Fire extinguishers can be heavy, so it's a good idea to practice picking

up and holding an extinguisher to get an idea of the weight and feel. Take time to read the operating instructions and warnings found on

the fire extinguisher label. Not all fire extinguishers look alike. Practice releasing the discharge hose or horn and aiming it at the base

of an imagined fire. Do not pull the pin or squeeze the lever. This will break the extinguisher seal and cause it to lose pressure.

When it is time to use the extinguisher on a fire, just remember PASS!

Pull the pin. Aim the nozzle or hose at the base of the fire from the recommended

safe distance. Squeeze the operating lever to discharge the fire extinguishing agent. Starting at the recommended distance, Sweep the nozzle or hose

from side to side until the fire is out. Move forward or around the fire area as the fire diminishes. Watch the area in case of re-ignition.

Fire Extinguisher Inspection

Like any mechanical device, fire extinguishers must be maintained on a regular basis to ensure their proper operation. You, the owner or occupant of the property where the fire extinguishers are located, are responsible for arranging your fire extinguishers' maintenance.

Fire extinguishers must be inspected or given a "quick check" every 30 days. For most extinguishers, this is a job that you can easily do by locating the extinguishers in your workplace and answering the three questions below.

Is the extinguisher in the correct location? Is it visible and accessible? Does the gauge or pressure indicator show the correct

pressure?

Fire Extinguisher Maintenance

In addition, fire extinguishers must be maintained annually in accordance with local, state, and national codes and regulations. This is a thorough examination of the fire extinguisher's mechanical parts, fire extinguishing agent, and the expellant gas. Your fire equipment professional is the ideal person to perform the annual maintenance because they have the appropriate servicing manuals, tools, recharge materials, parts, lubricants, and the necessary training and experience.

How to Use a Fire Extinguisher

It’s easy to remember how to use a fire extinguisher if you remember the acronym PASS: Pull Aim Squeeze Sweep

How to Use a Fire Extinguisher

Pull the pin… This will allow you to discharge

the extinguisher

How to Use a Fire Extinguisher

Aim at the base of the fire…Hit the fuel.If you aim at the flames... … the extinguishing agent will fly

right through and do no good.

How to Use a Fire Extinguisher

Squeeze the top handle… This depresses a button that

releases the pressurized extinguishing agent.

How to Use a Fire Extinguisher

Sweep from side to side… Start using the extinguisher from a

safe distance away, then slowly move forward.

.. until the fire is completely out.

Once the fire is out, keep an eye on the area in case it re-ignites.

Fire Extinguisher Maintenance

What is a fire alarm system?

A fire alarm system is number of devices working together to detect and alert people through visual and audio appliances when smoke/fire is present. These alarms may be activated from smoke detectors, and heat detectors.

What is a central station fire alarm system?

An Alarm Monitoring Center or Central Monitoring Station (also known as "CMS") is a company that provides services to monitor burglar, fire and residential alarm systems. The Central Monitoring Station may also provide watchman and supervisory services.

What are the methods of detecting fire?

A flame detector is a sensor designed to detect and respond to the presence of a flame or fire. Responses to a detected flame depend on the installation, but can include sounding an alarm, deactivating a fuel line (such as a propane or a natural gas line), and activating a firesuppression system.

What is a fire alarm control panel?

A fire alarm system is number of devices working together to detect and alert people through visual and audio appliances when smoke/fire is present. These alarms may be activated from smoke detectors, heat detectors, water flow systems, which are automatic or from a manual fire alarm pull station.

Fire Detection and Alarm Systems

What are we going to review?

1) Why are fire detection & alarm systems installed?

2) Types of alarm systems3) Automatic alarm initiating devices

3.1) Heat detectors3.2) Smoke detectors3.3) Flame detectors3.4) Fire – gas detectors

What are we going to review? cont.

4) Combination detectors5) Indicating devices6) Automatic alarm systems

- Remote station system - Proprietary system - Central station system

What are we going to review? cont.

7) Supervising fire alarm systems 8) Auxiliary systems

9) Fire alarm systems – general info.

1) Why are fire detection and alarm systems required?

Notify building occupants to take evasive action to escape the dangers of a hostile fire

Summon organized assistance to initiate or assist in fire control activities

Initiate automatic fire control & suppression systems & to sound alarm

1)Why are fire detection and alarm systems required? cont.

Supervise fire control & suppression systems to assure operational status is maintained

Initiate auxiliary functions involving environmental, utility & process controls

Systems may incorporate one or all of these functions

Fire detection & alarm system’s components

System components may operate :

mechanicallyhydraulicallypneumatically orelectrically

2) Types of fire alarm systems Most basic type is designed to only

be initiated manually – known as a local system or protected premises (pull station & bell)

Typically, this system is expanded to include fire detection devices to sense the presence of a fire and initiate a signal

3) Automatic alarm initiating devices

3.1) Heat detectors – fixed temp. & rate-of-rise

Fixed-temperature devices › Oldest types in use› Relatively inexpensive› Least prone to false alarms› Activation temperature slightly above

highest ceiling temperature

Fixed temp. heat detectors cont.

Detect heat by one or more of 3 primary principles of physics:

Expansion of heated material Melting of heated material Changes in resistance of heated

material

Fixed temp. heat detectors cont.

Fusible devices and frangible bulbs can be used but are typically found in???

oAutomatic sprinklers

(Review this section on page 560)

Fixed temp. heat detectors cont.

Most detectors are of the spot type Designed to detect heat in only in a

relatively small area surrounding the spot they are located

May find continuous line detection devices – detect heat over a linear area parallel to the detector (eg. conveyors, electric cable trays etc.)

Fixed temp. heat detectors cont.

May also find bimetallic detectors Uses 2 metals with different thermal

expansion characteristics When heated, 1 metal expands faster

than the other causing the strip to bend or arch

Deflection of strip makes or breaks alarm circuit, initiating an alarm

Bimetallic detectors will reset automatically when cooled (but should be checked after a fire for damage)

Rate-of-rise heat detectors Operate on the principle that the

temperature in a room will increase faster from fire than from atmospheric temperature

Will initiate an alarm when the rise in temp. exceeds 12-15F (7-8C) per minute

Alarm can be initiated at a temp. far below that required for a fixed-temp. device

Rate-of-rise heat detectors

Reliable devices, not subject to false activations

But if not properly installed, they can be activated under nonfire conditions (eg. detector located too close to doorway and subject to extreme fluctuations in temperatures)

Rate-of-rise heat detectors Several different types of

detectors:› Pneumatic rate-of-rise spot

detector› Pneumatic rate-of-rise line

detector› Rate compensated detector› Thermoelectric detector

(Review details on pages 562 & 563)

3.2) Smoke detectors Can initiate an alarm much quicker

than a heat detector because it responds to smoke generated very early in a fire’s development (incipient stage)

2 basic types:› Photoelectric› Ionization

3.2) Smoke detectors cont.• Photoelectric smoke detector Uses a photocell coupled with a

specific light source Basically smoke entering the

smoke detector chamber disrupts the light beam causing an alarm signal to be initiated

More sensitive to smoldering fires

3.2) Smoke detectors cont.• Ionization smoke detector Invisible products of combustion enter

the chamber decreasing the current between the –ve & +ve plates, thereby initiating an alarm signal

Generally responds faster to flaming fires versus smoldering fires

Automatically resets when the atmosphere clears

Power sources for smoke detectors Can be batteries or household power Battery operated are easy to install

and are economical to purchase Independent of house power so they

will operate during power failures BC Fire Code will permit battery

operated units (existing buildings)

Power sources for smoke detectors cont.

BC Building Code requires hard wired smoke alarms for new construction

Should install both on every level of home plus in the sleeping rooms

Lack of maintenance (ie. not replacing batteries) is greatest concern

Change your clock – change your battery

3.3) Flame detectors 3 basic types of flame

detectors: Ultraviolet light (UV) Infrared (IR) Can detect both types of light Most sensitive to detect fires but also easily activated by

nonfire conditions (eg. welding, sunlight etc.)

3.3) Flame detectors cont. Must be positioned with an

unobstructed view of the protected area

Will not activate if line of site is blocked

IR detectors are designed to require the flickering motion of a flame

UV detectors insensitive to sunlight so they can be used in areas not suitable for IR detectors

3.4) Fire-gas detectors Monitors levels of carbon dioxide and

carbon monoxide (common to all fires)

More discriminating than other detectors – can be designed to be sensitive only to gases produced by specific types of hostile fires and ignores gases produced by friendly fires

Not many in use – very specialized applications

4) Combination detectors

Single device can be designed to have more than 1 function eg. heat/smoke, smoke/carbon monxide detectors

Different combos make the detectors more versatile and more responsive to fire conditions

5) Indicating devices Audible and visible alarms

Audible: could be bells, horns, chimes

Visible: strobes

May be used together

6) Automatic alarm systems Depending on the BC Building Code

requirement, some occupancies (eg. schools) are required to transmit an alarm signal to an off-site location

Purpose: notify fire departments Signal produces an automatic

response upon activation of local alarm on protected property

6) Automatic alarm systems Can use dedicated wire pairs, leased

telephone lines, fiber-optic cable or wireless communication links

Refer to BC Building Code for occupancies required to transmit a signal off-site

Still request occupants call 9-1-1 should there be a problem with link

Auxiliary Systems 3 types of systems:

Local energy (municipal fire alarm boxes installed-wired directly to fire dept.)

Shunt (circuits from municipal fire alarm system extended into protected property)

Parallel telephone (alarm directly to center over municipally controlled telephone line)

6) Automatic alarm systems – Remote station system

Remote station system transmits alarm, supervisory and trouble signals from protected property to a remote location where action is taken

Owners pay a monthly fee to a monitoring company

Most popular method of off-site monitoring

6) Automatic alarm systems – proprietary system

Used to protect large commercial and industrial buildings

Each building has its own system that is wired into a common receiving point somewhere on the site

Receiving point must be in a separate building or area remote from any hazardous operations

Constantly staffed with special training to handle all types of calls

6) Automatic alarm systems – central station system

Similar to a proprietary system Primary difference: receiving location

for calls is off-site, at a central station, and monitored by non-staff

Central station is an alarm company that contracts with individual customers

Alarm received, info taken, and initiate emergency response

6) Automatic alarm systems – central station system cont.

Call fire department and property contacts

May have supervised telephone lines

7) Supervising fire alarm systems

Fire alarm systems designed to be self-supervising (ie. if system not operating normally, a trouble signal is generated)

May happen when system switches to battery back-up during a power outage, break in a detector or notification circuit etc.

7) Supervising fire alarm systems cont.

Fire alarm and supervisory systems may be installed to complement wet or dry sprinkler systems

Flow and pressure devices are installed to supervise the systems

Movement in the devices would indicate a sprinkler head activation due to a fire or water leak due to pipe break etc.

8) Auxiliary services

Technological improvements in fire alarm systems have enhanced their capabilities

Systems now integrate process and environmental controls, security and personnel access controls etc.

8) Auxiliary services cont.

Some of the auxiliary services available are:› Smoke control in HVAC systems› Closing fire doors and dampers› Assisting with evacuation by increasing air

pressure in stairwells› Overriding elevator controls› Controlling personnel access to hazardous

areas etc. etc.

9) Fire alarm systems – general info.

30% of calls with alarm bells ringing and no fire in 1999

Zones indicated on fire alarm panel Re-setting alarm systems - who? Silencing of bells – who?

Evacuation signs Emergency  Evacuation  is the

immediate and urgent movement of people away from the threat or actual occurrence of a hazard. Examples range from the small scale evacuation of a building due to a storm or fire to the large scale evacuation of a district because of a flood, bombardment or approaching weather system.

Fire Emergency Evacuation Plan and the Fire Procedure

A fire emergency evacuation plan (FEEP) is a written document which includes the action to be taken by all staff in the event of fire and the arrangements for calling the fire brigade. It can include any relevant information in relation to the FEEP.

EXAMPLE

FIRE FIGHTING ROBOT

CONTENT

• Introduction• Robot• How Does It work• Block Diagram• Software And Hardware Requirements• Specification• Circuit Diagram• Power Supply• Working Of Fire Fighting Robot• Advantages • Limitation • Application • Future Scope • Reference

Introduction This is movement based robot. It used

to sense the fire and spreads the water over that direction.

In this, we use RF communication to communicate between robot and control room that is placed in a remote place.

Robot Robot exactly, is a system that

contains sensors, control systems, manipulators, power supplies and software all working together to perform a task. Designing, building, programming and testing a robot is a combination of physics, mechanical engineering, electrical engineering, structural engineering, mathematics and computing.

How does it work? Stays balled-up until its sensors pick up

a fire within a half-mile radius. Self-guided by GPS, intelligent feelers,

infrared and heat sensors. Has six legs to navigate itself through

and around obstacles

Software And Hardware Requirements

Software Tools: WINAVR to compile the source file and

generate the hex code. AVR Studio 4.18 AT Prog to programmer the microcontrollerHardware Tools: AVR Microcontroller IR Sensor DC motors Pump

Specifications Made from fire-resistant ceramic-fiber

compounds.

Can stand temperatures up to 1850 ̊ F.

The robot is equipped with tanks of water and powdered fire extinguishing agents.

Circuit diagram

Microcontroller

• The micro controller is the most important of the design – acts as the brain for robot

• Interfaces all sensors and motors

• Contains all code for robot operations

FEATURES of ATMEL 89C51 µc

4k Bytes of In-System Reprogrammable Flash Memory

128 x 8-bit Internal RAM

32 Programmable I/O Lines

Six Interrupt Sources

On chip oscillator & clock circuitry

ROBOT CONTROLLER The controller is the part of the

Robot which operates the mechanical arm and maintains contacts with its environment. This device is a combination of hardware and software which enable it to carry out its assigned tasks.

WORKING OF FIRE FIGHTING ROBOT

• The robot along with two sensors moves in all the directions from its mount position. When the flame or high temperature point is detected, the Robot motion will stop automatically and indicates fire has been detected.

• Then the Signals from the sensors are sent

to the computer terminal and it activates the fire preventive system.

Robo Pic

This is what Bot ,by placing sensors appropriately we can efficiently detect the location of fire.

Where would it be useful? Would be most valuable to have in

small business stores, factories, or restaurants.

Germany plans to place these bugs in campgrounds in order to prevent wildfires.

ADVANTAGES

The fire detecting Robots helps in following ways:

To detect the exact direction of the fire source.

Capability of sensing accurately with increased flexibility

Low cost in the long run Reliable and economical

Limitations Many believe it will be a better scout

than firefighter. Cannot leave outside for long

periods of time due to battery life. It is not meant to put out large fires.

Application

Can be used in Server rooms for immediate action in case of fire

Can be used in extinguishing fire where probability of explosion is high. For e.g. Hotel kitchens, LPG/CNG gas stores, etc.

Every working environment requiring permanent operator's attention. -At power plant control rooms. -At captain bridges. -At flight control centers.

FUTURE SCOPE

• As we all know that these days Pakistan is sick off massive fire tragedy, to avoid such disasters, technological power must exceed human power because “Human life and time are priceless”.

• Extended to a real fire extinguisher by replacing the water carrier by carbon dioxide Carrier.

Thank you