Learning about the automatic Fire & Smoke alarm Systems

Fire and smoke alarm systems is a set of equipment that detect and alarm when a fire occurs. This system is especially needed in high-rise buildings, factories or in family homes. The detection of fire signals can be done automatically by the equipment or by humans, and must be operated continuously for 24/24 hours. Thanks to that so we can avoid the dangers of fire, anticipate the imminent danger (thanks to the system of probes, smoke detectors, heaters, gas detectors …), can Easy to handle when a problem occurs (thanks to the fire engine designed properly, perfect and very easy to use).

COMPONENTS OF A FIRE ALARM SYSTEM, AUTOMATIC RECOGNITION

A typical fire alarm and smoke alarm system will have three components:
1- Fire Alarm Center
Designed cabinet, including the main equipment: boiler, transformer and battery

2- Input device
– Headlight: smoke alarm, heat detector, gas alarm, fire alarm.
– emergency switch (emergency push button)

3. Output device
– Display panel (keyboard).
– Alarm bells, sirens.
– Warning lights, exit lights
– Automatic phone dialer.

PRINCIPLES OF OPERATION OF THE FIRE ALARM SYSTEM

The operation of the smoke alarm system is a closed process. When there is a phenomenon of fire (such as sudden increase in temperature, smoke or sparks), input devices (detectors, emergency switches) receive signals and transmit information. Trouble with the fire control center. The center handles the received information, locates the location of the fire (via zones) and transmits the information to the output devices (sub display panel, bell, horn, lamp). These devices will emit light and sound signals so people know where the fire is and handle them in time.

CLASSIFICATION OF THE FIRE ALARM SYSTEM

The fire alarm system uses two different voltages: 12V and 24V.
Theoretically both of these have the same technical and functional properties. But, compared to 24V fire alarm system, 12V fire alarm is not professional, 12V center is mainly used in burglar alarm system, in addition, the system also requires a programming keyboard. While the 24V fire alarm system is a professional fire alarm system, the signal transmission capability goes further, and programming keys are not required. However, the center of processing 12V fire alarm system is less expensive than the center of processing fire alarm 24V

In addition, the fire alarm system is divided into two main systems, including:

1- Common fire alarm system:
With simple features, low price, fire alarm system is usually only suitable for installation in areas of small or medium size (about several thousand m2), the number of rooms is not much (several dozen rooms) ; Installations for small houses … The equipment in the system is connected to each other and connected to the fire alarm center, so when the central problem can only identify the overall and the whole display Zone that the monitoring system (not exactly the location of each newspaper, each location has a fire). This limits the ability of supervisors to handle

2- Addressable fire alarm system:
With high technical features, the fire alarm system is used for installation at large areas (several tens of thousands m2), divided into many independent areas, rooms in each area separately. . Each device in the system is directly connected to the fire control center, which helps the fire department receive fire signals in each area and place in a clear and accurate manner. From there the center can identify the problem details in detail and is displayed on the display panel to help the supervisor handle the problem quickly.

EXPLANATION DETAILS OF THE EQUIPMENT

1- Fire Alarm Center:
This is the most important device in the system and determines the quality of the system. A power supply for fire alarms. It is capable of receiving and processing fire alarm signals from automatic fire alarms or technical trouble signals, displaying information about the system and issuing an alarm command indicating the location of a fire. In case of necessity, the signal can be transmitted to the fire alarm reception. Ability to self-test the normal operation of the system, indicating the breakdown of the system such as break, short circuit.

2- Input Devices:
A device that is sensitive to fire phenomena (heat, smoke, light, flame), and is responsible for receiving information on the location of the fire and the signal to the fire control center.

2.1- Detector:

2.1.1 Smoke Detector:
– A direct monitoring device that detects smoke signals to transmit smoke signals to the processing center. Time the smoke detectors receive and transmit information to the fire alarm no more than 30 seconds. Environmental density ranges from 15% to 20%. If the concentration of smoke in the environment in the area exceeds the permitted level (10% -20%), the equipment will send an alarm signal to the center for processing.
Smoke detectors are usually located in the study halls, halls, warehouses, closed spaces and pre-combustion fumes.
– Smoke detector is divided into two main categories as follows:

2.1.1.1 Point smoke detector.
Installed in areas where monitoring is small, low ceilings (offices, apartments, etc.)
Asian. Ion smoke detector: The device generates positive and negative ions that move in the presence of smoke and smoke, which interferes with the movement of positive and negative ions. Mind processing.
B. Photo Smoke Detector (photo): The device consists of a pair of detectors (one transmitter, one receiver) arranged opposite each other, when there is smoke between the two alarms, the smoke will obstruct the transmission line. The signal between the two alarms, from which the alarm will send fire signals to the processing center.

2.1.1.2 Beam Smoke Detector
– Includes a pair of devices mounted at the ends of the area to be monitored. The projection device emits an infrared beam through the area of ​​the surveillance area and then to a receiver containing a photoelectric cell that monitors the signal balance of the beam of light. This detector operates on the principle of blurring light, which contrasts with the scattering principle of light (smoke in the head).
– Beam smoke detectors have a very wide range (15m x 100m), appropriate use in areas where photoelectric smoke detectors are unsuitable, such as in places where smoke Will there be black smoke?
– Moreover, the Beam head can withstand the extreme conditions of temperature, dust, excessive humidity, many impurities, etc. Due to the Beam head can be placed behind the glass window, so Very easy to clean, preserve.
– Beam detectors are usually installed in areas with large monitoring range, ceiling is too high to install point detectors (factories, etc.)

2.1.2 Heat Detector
– The heat detector is used to detect the temperature of the environment within the protection range, when the temperature of the environment does not meet the requirements of the manufacturer’s prescribed heaters, it will signal The alarm sent to the processing center.
– Heat detectors are installed in areas where smoke detectors can not be installed (where machinery, garages, kitchens, factories, kitchens, etc. are installed)

2.1.2.1 Fixed heat detector
The type of alarm triggered and triggered an alarm when the temperature in the air around the alarm head increased to the manufacturer’s specified level (57o, 70o, 100o …).

2.1.2.2 Increased temperature sensor

A type of alarm triggered and triggered an alarm signal when the ambient air temperature sensor senses a sudden increase in temperature of about 9 ° C / min

2.1.3 Gas Detector
– It is a direct monitoring device that detects gas when the gas concentration exceeds 0.503% (Propane / Butane) and sends an alarm signal to the treatment center.
Gas detectors are usually located near gaseous locations such as gas rooms or gas storage facilities. Gas detectors mounted on the wall, 10-16cm from the floor, absolutely not allowed to be installed on the floor.

2.1.4 Flame Detector
– A device that senses ultraviolet light emanating from the flame, receives a signal, and sends an alarm signal to the central processing unit when it detects fire.
– Used primarily in places where there is a high risk of fire, where the light of the flame is a symbol of fire (eg flammable liquid storage).
– The fire detector is very sensitive to ultraviolet rays and has been thoroughly researched to avoid false alarms. The transducer transmits an alarm signal to the fire control center when there are two ultraviolet induction pulses after two periods, each period of 5 seconds.

2.2- Emergency breaker
Installed in visible locations of the staircase corridors for use when needed. This device allows the user to proactively transmit fire alarms by pressing or pulling on emergency switches, emergency alarms for anyone present in the area known to have fire-fighting measures and Move out of the danger zone by exits. These include the following types of emergency switches:
2.2.1 Urgent, square
2.2.2 Break glass
2.2.3 Urgent

3- Output Devices:
Receive signals from the fire control center to transmit and have the ability to transmit information by sound (bells, horns), by light signals (lights) to help people aware of the phenomenon of fire occurs.

3.1 Provision table display
Displays information about areas of the incident from the fire alarm center, to help identify the situation where the problem occurred to handle in time.

3.2 Fire alarm bell
Installed in a security room, rooms have concierge staff, corridors, stairs, or crowds of traffic to inform people around who may be experiencing the problem. Reason, evacuate in time.
When a fire alarm occurs, the alarm will sound an alarm that will let the security guard recognize and pass through the fire alarm monitor (the secondary display panel) to know which area is affected by the fire. Echelon, from which to promptly notify the staff responsible for fire prevention, troubleshooting or appropriate handling measures.

3.3 Fire alarm siren
It has the same features and installation location as the fire alarm, but the whistle is used when the distance between the place of notification and the place where the alarm message is received is too far away.

3.4 Lights
It is used to send alarm signals, each type of lamp has different functions and is installed in the appropriate position to maximize the features of this device. Including types of lights:

3.4.1 Exit Light
Placed near the stairs of each floor, indicating the escape route in the event of a fire. Auto illumination in case of AC power loss.

3.4.2 Corridor Lamp
Placed above the emergency switch of each floor. The warning light will light up whenever the emergency switch is active, and this is also the emergency light for those present in the building. This is important, as during the confusion caused by the fire, the user should clearly distinguish the emergency work that triggered the fire pump.

3.4.3 Room Lamp
Installed in front of each room to identify any problem quickly and easily.

3.4.4 Emergency Light:
When there is fire alarm, the first operation is to power off. Now the light will automatically come on (thanks to the battery backup battery), it makes it easy for people to find escape routes, or help the responsible staff to quickly carry out the task. Or, in the event of a sudden power outage due to an electrical problem, the Emergency light is also working.

3.5 Automatic phone dialer
Installed in a fire control center, when receiving a fire alarm from the center of the unit, will automatically dial the pre-set telephone number to inform the primary responsible person. Normally dial 3 to more than 10 numbers.

3.6 Keypad:
Is a means to control all system activities. Through the keyboard, you can easily control the activity you want, such as entering system commands into monitor mode, or you can stop monitoring some areas throughout the system, or It is possible to program the system to automatically switch to monitoring mode at certain times of the day for certain areas.

3.7 address module:
The address module is used in the fire alarm system, which is able to tell exactly where the fire occurred in a protected area.

DIAGRAM OF FIRE AND RECOGNITION SYSTEM:

1. Fire Extinguisher

2. Pipe system

3. nozzles

4. Display screen

5. Alarm bell

6. System Activation Manual

7. Clock operating mode indicator

8. Probe, head

9. Fire screen

10.Center