B. Karlov, V. Pevzner, P. Slepenkov, a textbook for an amateur navigator (control of small vessels). Fire detection systems on ships and ship fire alarms Ship alarms. Ship alarm systems

3.5. What is an old alarm system good for? When replacing alarm units in industrial premises and private apartments, “old” units often remain unclaimed, which can be successfully adapted to imitate an installed alarm system - in other apartments,

3.8. Alarm from improvised means or any door under control In order to inform the owner about the arrival of guests, the opening of a particular door in an apartment (multi-room) building, a simple sound alarm created from improvised parts is useful.

Ship fire alarm system. The principle of operation of the alarm.

The purpose of the automatic fire alarm system is to notify about the outbreak of a fire and the introduction of volumetric fire extinguishing means. Automatic fire alarms are now becoming even more important due to the reduction in the number of watches in engine rooms and the organization of unattended maintenance of individual ship premises.

Vessels equipped with fire alarms for fire detection and warning have a central fire station (CFS). Receiving alarm stations alerting the crew, passengers and production personnel about a fire are concentrated at the control center.

The electrical fire alarm system and smoke alarm system are designed to detect fire (fire) and report the location of its occurrence. Electrical fire alarm systems can be automatic or manual. Electrical fire alarm systems, depending on the type of detectors used, can be thermal (reacting to an increase in ambient air temperature), smoke (reacting to the appearance of smoke), light (reacting to the appearance of an open flame), combined (reacting to heat, smoke and light) . The main elements of an electrical fire alarm system are detectors, a receiving station, a power supply and linear structures.

Detectors are fire signal sensors. Receiving stations receive electrical signals from detectors and convert them into light and sound. Linear structures connect detectors to the receiving station.

Residential and service premises, storerooms for storing ship supplies of explosives, flammable and combustible materials, control posts, and dry cargo rooms are equipped with automatic fire detection alarms.

An automatic fire detection alarm may not be installed: in dry cargo spaces not equipped with volumetric fire extinguishing systems; in residential and service areas of passenger ships or the first method of constructive fire protection (except for explosives storerooms); in rooms in which there is no hot environment at all, on passenger ships with a gross tonnage of at least 100 per. i.e., without sleeping passenger seats, with a flight duration of no more than 12 hours; on dry cargo ships with a gross tonnage of 1000 per. t and on all non-self-propelled tankers.

Passenger and equivalent ships and other ships with a gross tonnage of more than 1000 per person are equipped with manual fire alarms. t (except for non-self-propelled vessels).

Fire alarm call points are installed in the corridors of residential, service and public premises, in machinery spaces, and on open cargo decks. Sensors should be located in easily accessible places and clearly visible. On passenger ships and similar ships, heat detectors have greater intensity than smoke and light detectors, and are used in relatively small spaces. Smoke detectors are used in rooms where a fire may occur from smoldering, as well as in rooms of great height and where it is necessary to give an alarm at an earlier stage of the fire than can be done with heat detectors.

Light detectors are used in rooms with large area and in especially critical premises.

To protect explosive ship premises, fire alarm sensors of the type DPS-038, DPS-2 with executive bodies type PIO-17, PIO-028, through which detectors are connected to existing receiving stations of the electric fire alarm system of the radial system.

Automatic fire detectors are installed in enclosed areas of the ship, manual fire detectors are installed both indoors and outdoors. Detectors installed in places where mechanical damage is possible are equipped with protective devices.

Automatic heat detectors can be of maximum and differential action. Automatic heat detectors of maximum action are triggered when the ambient air temperature rises above a predetermined limit. Automatic differential fire detectors are triggered by a sharp increase in ambient air temperature. Differential action detectors are usually installed in rooms where there are usually no sudden increases in air temperature.

Heat detectors are installed in areas where fires are more likely to occur, in places where there is a possible accumulation of warm air, heated by a fire source, as well as taking into account convection air flows caused by supply and exhaust ventilation. Heat detectors are not installed near heat sources that could affect the operation of the detectors.

Automatic fire detectors that respond to the appearance of smoke are used in cases where the occurrence of a fire is accompanied by abundant smoke (burning of wood-fiber and rubber products and materials, electrical equipment).

Smoke detectors are installed in rooms with possible air temperature fluctuations from -30 to +60°C with a relative air humidity of 80% at 20°C. Smoke detectors are also installed in rooms where the air contains vapors of acids or alkalis. The number of smoke detectors installed in the protected room depends on the configuration of the room, the design of the ceiling, the load of the room with materials and equipment, and a number of other conditions.

Ionization-type smoke detectors are installed at an average rate of one detector per 100 m2 of room area.

In cases where, for technical reasons, it is not possible to install smoke detectors in the protected premises, a method of air sampling using a ventilation system or special devices for air suction is used.

The speed of air movement in pipelines at the places where detectors are installed should not exceed 0.5 m/s; the length of the pipeline from the air intake point to the detector should be as short as possible and should not exceed 15 m.

Automatic fire detectors that react to the appearance of a flame are used in enclosed spaces with air temperatures from -10 to +40°C and relative humidity up to 80%.

In the rooms where light detectors are installed, there must be no sources of ultraviolet rays, gamma radiation and open flames (operating welding machines, electrical sparks). Light detectors cannot be installed in rooms where the air contains vapors of acids and alkalis.

Light detectors are installed on the ceiling so that the detector “sees” the entire room, especially the most likely places of fire. The distance from the light detector to the most distant point “visible” by it should not be more than 30 m. Light detectors are protected from direct sunlight and direct exposure to lighting lamps.

Manual fire call points are divided into push-button, operating in beam alarm systems, and code, operating in ring systems.

In electrical fire alarm systems, push-button detectors can be used to duplicate the operation of automatic detectors. Manual call points are installed both indoors and outdoors at ambient temperatures from -50 to +60°C and relative humidity 98%. Indoors, manual call points are installed in passages and corridors. The locations where detectors are installed must have sufficient illumination. Manual call points are installed on bulkheads so that the push button is 1.3 m above the floor level and is freely accessible.

IN beam system Up to five push-button detectors serving one address can be connected to one pair of wires. In a ring system, up to 50 coded fire detectors will be connected to the line.

Fire detection alarm receiving stations show from which room or group of rooms the signal came from when the detector sensor was triggered. These stations are equipped with a mnemonic diagram indicating the premises served by each beam. The effect of the sound signal on the CPP does not depend on the light signal. The effect of the light signal does not stop until the causes that caused it are eliminated. On passenger ships, fire signals received at the control center are duplicated to the watch or fire officer's room.

The automatic smoke alarm system consists of a camera with a photocell that detects smoke. This chamber continuously analyzes the transparency of the air supplied from the protected premises through a network of pipelines thanks to the vacuum created by the suction fan. Depending on the type of device, it can perform fire protection of individual premises located at a distance of 300 m from the detection camera. The appearance of traces of smoke in any of the premises protected by equipment instantly triggers a signal in the fire alarm system.

The use of a special circuit that detects smoke in the air using the method of an electric pulse of a photocell obtained by comparing the transparency of the air guarantees high sensitivity and reliability and at the same time automatically indicates the room in which the fire (smoke) appeared, with sound and light alternately operating fans installed near the receiving station . The fans create a vacuum that ensures the passage of smoke from the most distant receiver to the control center in no more than 1.5 minutes.

The air sucked from the premises is discharged into the atmosphere when passing through the receiving device. However, part of it, going through the smoke alarm pipeline, goes directly to the control center so that if smoke appears in the protected area, it can be detected there. All pipelines of the smoke alarm system have a device for periodically blowing them with compressed air (once a month).

To ensure that a fire can be detected at an early stage, all ships are equipped with fire detection equipment. First of all, this applies to fire alarms, but for the same purposes a video surveillance system installed on a ship, as well as various security systems, can be used.

The ship's fire alarm system consists of:

1. Automatic fire alarm sensors installed in various areas of the ship.

2. Fire detectors, activated manually when signs of fire are detected. Due to the small size of river vessels, fire detectors may not be installed, but they are required to be installed on passenger ships and tankers.

3. Fire alarm panel, which is installed on the navigation bridge and where signals from sensors and fire detectors arrive.

Automatic fire alarm sensors are one of the main parts of the system that ensures fire safety. It is the degree of reliability of the sensor of such an alarm that determines the overall effectiveness of the system, which ensures fire safety.

Fire sensors are divided into four main types:

1) thermal sensors

2) smoke detectors

3) flame sensors

4) combined sensors

1) The fire alarm thermal sensor responds to the presence of temperature changes. From a device point of view, thermal sensors are divided into:

a) threshold - with a specified temperature limit, after which the sensors will operate.

b) integral - react to a sharp rate of temperature change.

Threshold sensors - have relatively low efficiency, which is due to the temperature threshold at which the sensor is triggered, about 70 ° C. And the demand for this type of sensors is determined by its extremely low price.

Integrated fire sensors are capable of registering a fire in the early stages. However, since they use two thermoelements (one in the sensor structure itself, and the other is located outside the sensor), and a signal processing system is built into the sensor itself, the price of such fire sensors will be noticeable.

Fire alarm heat detectors should only be used when the primary symptom of a fire is heat.

2) Fire alarm smoke detectors detect the presence of smoke in the air. Almost all manufactured smoke detectors operate according to the principle of smoke particle scattering infrared radiation. The disadvantage of such a sensor is that it can work when there is a large amount of steam or dust in the room. However, a smoke detector is also extremely common, although, of course, it is not used in dusty rooms and smoking rooms.

3) The flame sensor implies the presence of a smoldering hearth or open flame. Flame sensors should be installed in areas where a fire is likely to occur without prior smoke emission. They are more effective than the two previous types of emitters, since flame detection is carried out at initial stage, when many factors are absent - smoke and a significant temperature difference. And in some production premises, which are characterized by a high level of dust or high heat transfer, only fire flame sensors are used.

4) Combination fire alarm sensors combine several methods for detecting signs of fire. In most cases, combination detectors combine a smoke detector along with a heat detector. This allows you to more accurately determine the presence of signs of fire in order to send an alarm to the remote control. The cost of these sensors is proportional to the complexity of the technologies used to create it.

The overall effectiveness of the fire extinguishing system directly depends on a properly designed fire alarm system, based on data received from the fire sensor. That is why the correct location, the use of a suitable type of sensor for certain rooms, as well as the quality of fire sensors allows us to determine

Fire alarm panel – installed on the navigation bridge. Designs may vary. Fire alarms can be combined with burglar alarms.

In the event of a fire, the fire alarm panel receives a signal that can come from either a sensor or a manual fire call point. The indicator lamp corresponding to any zone on the vessel will light up and a sound signal will sound. Thus, the watch commander will know in which part of the ship the fire occurred and a general ship alarm will be announced indicating the location of the fire.

To transmit information from the sensor to the central device, communication lines are used - cable routes that form beams, to each of which several sensors and manual call points are connected, located in the same or close to each other rooms.

The fire detection alarm must provide a quick identification of the object from which the signal was received, for which the use of mnemonic diagrams is preferable (and mandatory on passenger ships). When the detector is triggered, an audible and visual alarm must be triggered on the system control panel. If within 2 minutes these signals do not attract attention and their reception is not confirmed, an alarm signal is automatically sounded in all crew living quarters, service rooms, machine rooms, and control stations.

Some types of fire alarm systems provide not only the identification of the beam to which the triggered sensor is connected, but also the sensor number. For this purpose, a ballast resistor or capacitor is connected in parallel to the sensor contacts. When the sensor is triggered, its resistance is switched off and a circuit is formed with the remaining resistors, measuring the resistance in which allows you to determine the number of the triggered sensor.

PORTABLE FIRE FIGHTING EQUIPMENT

To extinguish small fires, as well as to prevent fires on ships, portable fire extinguishing equipment is used. According to the PPB for the military and military equipment of the Russian Federation: The use of fire protection systems, property and equipment for purposes other than their intended purpose is not permitted, except in cases provided for in the construction documentation, as well as during fire fighting exercises and training.

5. Koshma (fire blanket) - can be made from various materials: fiberglass, canvas, asbestos fabric. With the help of a felt you can extinguish fires of classes A, B and C.

6.
A box of sand and a shovel (scoop) must be on every ship. They are located mainly on the open deck and in the MKO. Sand, first of all, is not intended to extinguish a fire, but to prevent a fire. For example, when a flammable liquid is spilled, you need to cover it with sand as soon as possible, thereby eliminating the very possibility of its ignition and, in addition, the liquid will not be able to spread across the deck and get overboard, creating a threat of pollution. In addition, sand has dielectric properties, and when extinguishing a fire, it absorbs a lot of heat.

7. Fire extinguishers. We will discuss the design and use of portable fire extinguishers in the next chapter.

8. Firefighter suit and equipment. It will be studied in detail in the following chapters.

PORTABLE FIRE EXTINGUISHERS AND THEIR USE

Historical background

History of the fire extinguisher

The first fire extinguishing device was invented by Zechariah Greil, around 1715 in Germany. It represented wooden barrel, filled with 20 liters of water, equipped with a small amount of gunpowder and a fuse. In the event of a fire, the fuse was ignited, and the barrel was thrown into the fireplace, where it exploded and extinguished the fire. In England, a similar device was made by chemist Ambrose Godfrey in 1723. As an improvement to the design, alum was added to the water in 1770.

In 1813, English captain George Manby invented the fire extinguisher in the form in which we are familiar with it today. The device was transported on a cart and consisted of a copper vessel containing 13 liters of potash (POTASH (German Pottasche, from Pott - “pot” and Asche - “ash”) - potassium carbonate, potassium carbonate, a white crystalline substance, highly soluble in water), a chemical used in firefighting since the 18th century.

In 1850, another chemical fire extinguisher was introduced in Germany by Heinrich Gottlieb Kühn, a small box filled with sulfur, saltpeter and coal, with a small powder charge. The charge was activated using a fuse, the box was thrown into the fireplace, after which the released gases extinguished the fire.

The Fire Annihilator was patented in 1844 by Englishman William Henry Philips. While in Italy, Phillips witnessed several volcanic eruptions, which prompted him to think about extinguishing fire using water vapor mixed with other gases.

Here's how the Brooklyn Daily Eagle describes the failed demonstration of the "Exterminator":

“Yesterday, to satisfy our curiosity as to the merits of the so-called “Fire Destroyer,” we came to New York to witness the public testing of the machine, which had been previously announced. To avoid accidents, the test was carried out on the outskirts of 63rd Street, in an open space without any buildings in the vicinity. During the tests, flammable material was set on fire and the fire was extinguished using two devices. The material was spread over an area of ​​approximately six by four feet, the layer being approximately two or three inches thick. The first of the machines began to extinguish, and a stream of white steam coming out of it was directed towards the fire; on the other hand, a second vehicle was brought in to extinguish the fire. The extinguishing was accompanied by a strong hiss, however, when both cars exhausted their charge, the fire burned as strongly as before. The tests were repeated several times with the same results.

Since the tests were long delayed and were publicly announced, it can be assumed that everything was well prepared to show the true properties of the machine, and having witnessed them, we are forced to report that we have more confidence in the bucket of water than in the "Fire Destroyer." .

Dr. François Carlier received a patent in 1866 for the “L’Extincteur” fire extinguisher, the operating principle of which was based on the use of acid. For the first time in history, the fire extinguisher device made it possible to obtain the necessary pressure for release fire extinguishing agent inside the vessel itself. The reaction between "tartaric acid" and sodium carbonate (soda) produced large quantities carbon dioxide(CO2), which pushed out the contents of the fire extinguisher. The device was improved and patented again in 1872 by William Dick of Glasgow, who replaced tartaric acid with the cheaper sulfuric acid.

In 1884, engineer Schwarz from Bocholt, Germany, developed the "Patent Hand Fire Extinguisher", a tin pipe rectangular shape and triangular section. The pipe was filled with fire extinguishing powder, probably soda. The contents of the fire extinguisher had to be poured forcefully into the fire. Fire extinguishers of this design, in the form of tin containers and cartridge containers, were soon established throughout the world and lasted until the 1930s. Early

Carré's model was sold in several European countries, including Germany. Brothers Clemens and Wilhelm Graff were recruited as representatives in the regions of northern Germany. They soon improved the fire extinguisher design and introduced their Excelsior 1902 model. This model later became the famous Minimax fire extinguisher.

VeniVici fire extinguishers with an external compressed gas bulb

In the first decade of the new century, hundreds of companies produced fire extinguishers based on the use of water as a fire extinguishing agent. Public demonstrations were a successful method of promoting new designs and models. Usually they lined up in the city square wooden structures, and spectators watched the fire being put out, if, of course, the fire extinguisher worked.

Foam fire extinguishing technology was improved in 1934 by Concordia Electric AG, which introduced the first compression foam fire extinguisher, which produced foam under 150 atmospheres of air pressure. Soon, many companies, including Minimax, began to use foam fire extinguishing technology, which has proven itself to be the best in the fight against fuel fires. Based on foam fire extinguishers, stationary foam fire extinguishing installations have begun to be produced for use in engine compartments and other rooms using flammable liquids. Perkeo fire extinguishers have also been used to protect large volumes such as fuel tanks and fuel tanks, for which floating fire extinguishing devices have been launched.

In 1912, the first model of the Pyrene fire extinguisher, which was a hand pump, was released. chemical substance– carbon tertachloride (carbontetrachloride, CTC, formula CCl4) – has proven to be a very effective means of fighting fuel fires and extinguishing electrical installations under voltage (the extinguishing agent does not conduct current up to 150,000 volts). The only and most important drawback was that when heated, this agent produced a gas that was deadly to humans - phosgene, which could lead to death when using a fire extinguisher in limited space. In Germany in 1923, a law was passed limiting the capacity of carbon tetrachloride fire extinguishers to 2 liters in order to reduce the risk of large quantities of the deadly gas.

Pyrene Mfg. Co was founded in 1907 in New York City and manufactured its fire extinguishers and other products until the 1960s. The compact fire extinguisher has proven its effectiveness, and due to the increase in the number of automobile and fuel fires, the company has achieved a leading position in the CTC fire extinguisher market.

Pyrene factory assembly line, 1948

Soon, many companies mastered the use of CTC; in addition to fire extinguishers, it was used in fire grenades to improve their performance. Manufacturers such as Red Comet, Autofyre and Pakar sold them well into the '50s. Most CTC-based fire extinguishers were 1 gallon (4.5 liter) in size.

1 Gallon Pyrene Fire Extinguisher

The powder was already used as a fire extinguishing agent in the 1850s. Most designs relied on the use of sodium bicarbonate placed in tin containers or cartridges. In 1912, the Total company in Berlin received a patent for a powder fire extinguisher using carbon dioxide as a propellant. The gas was stored outside the fire extinguisher, in a separate container, and the effectiveness of extinguishing was achieved mainly thanks to it. Only later did the fire extinguishing ability of the powders reach an acceptable level.

Fire extinguishing powders have become the most commonly used fire extinguishing agent. The design of fire extinguishers has changed over time, nozzles and sprayers have been added, the quality of the powder and the ability to store it in large volumes have been improved. In 1955, the use of powders began. capable of extinguishing Class A fires such as burning wood or other solid combustible materials.

Antifyre Ltd of Middlesex, England, produced a fire pistol loaded with extinguishing powder cartridges in the 1930s. In addition to the powder, the cartridge contained a small powder charge, like a live cartridge. By pointing at the fire, pressing the trigger and releasing the powder, the fire could be extinguished from a distance. The company offered free reloads if the cartridges were used for extinguishing. Several large and small models were produced, supplied complete with several charges, in a steel box with a wall mount.

Several other manufacturers produced similar devices, sometimes using CTC or CBF as the agent in a glass or metal flask.

CO2 (carbon dioxide or carbon dioxide) has long been recognized as an effective fire extinguishing agent. The German scientist Dr. Reidt patented a method for storing liquid carbon dioxide in steel bottles in 1882 and soon, the company F. Heuser & Co from Hamburg began producing them. Around the same time, CO2 cylinders began to be produced around the world and soon, carbon dioxide fire extinguishers were included in the product range of all manufacturers. By 1940 there were several models, the design of which has remained virtually unchanged to this day.

Liquefied carbon dioxide is stored under high pressure in steel or, in the case of small volumes, aluminum containers. If necessary, gas can be supplied through a valve, flexible hose and wooden or plastic tip. When transitioning from liquid to gas, the temperature of the extinguishing agent is about -79°C, so frost may form at the outlets of the fire extinguisher. When the flammable substance is cooled and oxygen is replaced by inert carbon dioxide, the fire is extinguished.

At first, carbon dioxide fire extinguishers were mainly available in 5, 6 or 8 kilogram versions. Later, in the 1930s, large volume fire extinguishers began to be produced, transported on trailers and even on trucks.

Large volume Minimax fire extinguishers, transportable on a trailer

Some companies, such as Minimax in Germany, have begun to specialize in stationary installations gas fire extinguishing for ships, trains and manufacturing plants. Such systems included a large volume of liquefied carbon dioxide, smoke or temperature detectors and central system management. In addition, a network of pipelines with nozzles for distributing gas among the compartments.

Modern fire extinguishers have come a long way since their invention in 1715. Most compact fire extinguishers produced today are powder extinguishers, pressurized or with CO2 cartridges. Their design has remained unchanged since the 1950s, but of course all components have been improved to achieve greater reliability. In addition, modern fire extinguishing powders are certified and are used to extinguish various classes fires (flammable liquids, hard materials, electrical installations under voltage), which cannot be compared with the situation in the 50s.

The highly effective gas Freon was banned for use in fire extinguishers and fixed fire extinguishing installations almost worldwide in 2003 due to its destructive effects on the ozone layer. Currently, no real alternative has yet been found, so the market for gas fire extinguishers is dominated by fire extinguishers with liquefied carbon dioxide.

Halon fire extinguisher for helicopter

Currently, there are several types of foam fire extinguishers used to fight class A and B fires. The operating principle of most of them is based on the use of concentrated foam and cartridges with propellant gas.

Portable fire extinguishers are one of the most effective means of extinguishing fires at an early stage.

The following types of fire extinguishers are used in the navy:

· foam (air-foam);

· carbon dioxide (CO 2 -fire extinguishers);

· powder.

In addition to these three types, there are water and halon fire extinguishers, which are not used in the fleet for a number of reasons.

Let's look at the design and operation of fire extinguishers in more detail.

1. Foam fire extinguisher.

Foam fire extinguishers come in two types: air foam and chemical foam.

The air-foam fire extinguisher is designed to extinguish class A and B fires. The operating temperature range is from +5 to + 50 0 C. They are available in various sizes, with a charge weight from 4 to 80 kg.

Due to the fact that foam fire extinguishers contain water, problems arise when storing them on board river vessels in winter. Therefore, the river fleet tries not to use foam fire extinguishers. On navy ships operate all year round and foam fire extinguishers are very common.

A standard OVP-10 fire extinguisher weighs 15 kg.

To extinguish class A fires, fire extinguishers of the OVP-10A brand with a low-expansion foam generator are produced. To extinguish class B fires, OVP-10V brand fire extinguishers with a medium expansion foam generator are produced.

Air-foam fire extinguishers are not allowed to extinguish live electrical installations, as well as alkali metals.

The design of air-foam fire extinguishers is similar. The OVP-10 air-foam fire extinguisher consists of a steel body containing a 4-6% aqueous solution of foaming agent PO-1 (an aqueous charge solution based on secondary alkyl sulfates), a can high pressure with carbon dioxide, for pushing out the charge, a lid with a locking and starting device, a siphon tube and a bell-nozzle for obtaining high-expansion air-mechanical foam.

The fire extinguisher is activated by pressing the trigger lever with your hand, as a result of which the seal breaks and the rod pierces the membrane of the carbon dioxide cylinder. The latter, leaving the cylinder through the dosing hole, creates pressure in the body of the fire extinguisher, under the influence of which the solution flows through the siphon tube through the sprayer into the socket, where, as a result of mixing the aqueous solution of the foam concentrate with air, air-mechanical foam is formed.

The multiplicity of the resulting foam (the ratio of its volume to the volume of the products from which it is obtained is on average 5, and the durability (the time from the moment of its formation to complete disintegration) is 20 minutes. The durability of chemical foam is 40 minutes.

Preparing the fire extinguisher for use and operating procedures

1. Bring the fire extinguisher to the source of the fire at a distance of 3 m and install it vertically.

2. Unwind the rubber hose and point the foam generator at the source of the fire.

3. Open the locking device of the cylinder charged with the working gas until it stops.

After using the fire extinguisher, its body is washed with water and both the fire extinguisher body and the working gas cylinder are charged.

Chemical foam fire extinguisher - considered obsolete due to its poor effectiveness. Therefore, we will analyze its device briefly.

Inside the fire extinguisher there is a solution of soda (sodium bicarbonate) with the addition of cheap surfactants (surfactants) and a glass of acid. At the moment of operation, the glass opens, the acid comes into contact with the soda solution, resulting in the rapid release of carbon dioxide. The fire extinguisher is turned upside down and carbon dioxide forces the contents through the hole into the fire. Due to the presence of surfactants, a lot of foam is formed.

Before use, the fire extinguisher hole had to be cleaned with a metal rod: if it was clogged, it could cause trouble.

Chemical foam fire extinguisher OHP-10 (Fig.) is a welded cylindrical cylinder 1 made of sheet steel. In the upper part of the cylinder there is a neck 5 with an adapter 4, onto which a cast iron cap 8 with a locking device is screwed. The locking device consists of a rubber gasket 9 and a spring 10, which presses the plug to the neck of the glass 2 when the handle 6 with the rod 7 is closed and prevents its spontaneous operation. Using the handle, the plug is raised and lowered. For ease of carrying and working with the fire extinguisher, there is a handle 3 in the upper part of the body.

To activate the fire extinguisher, you need to turn handle 6 in a vertical plane until it stops, then take right hand by the handle, and with the left hand by the lower end, go as close as possible to the place of combustion and turn the fire extinguisher over with the lid down. In this case, the plug of the acid glass opens and the acid part flows out of the glass and, mixing with the alkaline solution, causes a chemical reaction with the formation of carbon dioxide CO 2, the stream of which is directed through the spray 11 into the source of intense combustion.

The OHP-10 fire extinguisher can be used to extinguish solid combustible materials, as well as flammable and combustible liquids in a small area. Since foam conducts electric current, this fire extinguisher cannot be used to extinguish burning electrical wires, electrical equipment and live appliances, as well as to extinguish fires in the presence of metallic sodium and potassium, burning magnesium, alcohols, carbon disulfide, acetone, calcium carbide. Due to the fact that a relatively high pressure is created in the fire extinguisher, before putting it into action it is necessary to clean the spray with a pin suspended from the handle of the fire extinguisher.

A very big drawback: the operation of the fire extinguisher is irreversible - once you have activated it, the fire extinguisher cannot be stopped (unlike, for example, a carbon dioxide fire extinguisher). As a result, the consequences of extinguishing a fire may be no less than the consequences of the fire itself. According to the apt expression of the chemist A.G. Kolchinsky:

"... eliminating the consequences of a foam fire extinguisher can be no less tedious than the consequences of a fire. This is one of those tools that are readily used to extinguish other people's fires, but rarely their own."

It is not surprising that, in accordance with NPB 166-97 (standards fire safety), chemical foam fire extinguishers were prohibited from being put into operation, and the existing OHP-10 fire extinguishers were replaced with other types of fire extinguishers.

Extinguishing tactics:

· when extinguishing, stay at least 3 m from the fire;

· avoid vigorously waving the fire extinguisher, direct the stream, smoothly moving it towards the center of the fire, the foam should slide over the burning surface;

Avoid getting foam on exposed areas of the body; Avoid splashing flammable liquids.

2.
Carbon dioxide fire extinguisher (CO 2 fire extinguisher).

Carbon dioxide fire extinguishers (CO) are designed to extinguish fires of various substances and materials, electrical installations under voltage up to 1000 V, internal combustion engines, and flammable liquids.

It is prohibited to extinguish materials that burn without air access (aluminum, magnesium and their alloys, sodium, potassium).

Operating temperature range: from -40 to +50 0 C.

The OU carbon dioxide fire extinguisher is a high-pressure steel cylinder (the pressure inside the housing is 5.7 MPa), which is equipped with a shut-off and starting device with an excess pressure relief valve and a plastic cone-shaped socket. The main color of carbon dioxide fire extinguishers is red.

The substance used in carbon dioxide fire extinguishers is carbon dioxide (CO2). It, carbon dioxide CO2, is pumped into a cylinder under pressure. The main task of a carbon dioxide fire extinguisher is to put down the flame. When a carbon dioxide fire extinguisher is activated, pressurized carbon dioxide is released in the form of white foam over a distance of approximately two meters. The temperature of the jet is approximately minus 74 degrees Celsius, so frostbite occurs when this substance comes into contact with the skin. The maximum coverage area is achieved by adjusting the direction of the plastic socket towards the source of fire. Carbon dioxide, falling on a burning substance, prevents the flow of oxygen, the low temperature cools and prevents the spread of flame, this stops the combustion process.

Carbon dioxide fire extinguishers are very effective at putting out flames at the beginning of a fire. It is best to use carbon dioxide fire extinguishers to extinguish something very important, something that cannot be damaged, for example, computers, equipment, car interior, because after
use, carbon dioxide evaporates and leaves no trace.

What to pay attention to:

Since the active substance of the fire extinguisher (CO 2) has a very low temperature, you must be careful not to freeze your hands during operation. To do this, only hold the fire extinguisher by the handles.

Short operating time, it is necessary to open the gas supply near the fire.

The highest efficiency when supplying gas directly to the fire.

Additionally, a fire extinguisher should not be used to extinguish fires on people due to the risk of causing frostbite.

When using several fire extinguishers in a closed room, oxygen deprivation may occur.

Not effective on open decks in windy conditions.

When starting and operating the fire extinguisher, it must not be held upside down.

3. Powder fire extinguishers.

Portable powder fire extinguishers general purpose designed to extinguish fires of classes A, B and C, and special purpose for extinguishing burning metals. The action of a fire extinguisher is based on interrupting the combustion reaction with virtually no cooling of the burning surface, which under certain conditions can lead to re-ignition. The fire extinguisher operates in a vertical position and it is possible to supply extinguishing powder in short portions.

Characteristics of powder fire extinguishers: charge weight 0.9-13.6 kg; jet flight range 3-9 m; operating time 8-30 s.

Extinguishing tactics:

· feed the powder continuously or in portions depending on the fire class, starting from the nearest edge, moving the stream from side to side;

· Move forward slowly, avoiding close contact with the fire;

· after the fire is extinguished, wait time to avoid re-ignition;

· extinguishing with powders can be combined with water extinguishing, and some powders are compatible with foam;

· When extinguishing, it is better to use a respirator.

You should remember some more rules for handling powder fire extinguishers: when using them, there may be a delay of 5 seconds, and also, it is better to use the entire charge at one time, since when supplied in portions, there is a possibility that the fire extinguisher will not work.

SHIP FIXED FIRE FIGHTING SYSTEMS

Now let's look at the stationary fire extinguishing systems that are used on ships. Fixed systems are designed and installed on ships when they are built, and what systems will be installed on the ship depends on the purpose and specification of the ship.

The main stationary fire extinguishing systems on board are: water extinguishing system, steam extinguishing system, foam extinguishing system, carbon dioxide extinguishing system (CO 2 extinguishing system), liquid chemical extinguishing system.

Water extinguishing system.

The water extinguishing system is based on the action of powerful jets of water that knock down the flame. All self-propelled displacement vessels are equipped with it, regardless of the presence of other extinguishing means on them.

Ship's water extinguishing system

Fire pump;

Fire hydrant with connecting nut;

Fire main.

Water extinguishing system design. Each self-propelled vessel has fire pumps. Their number depends on the type of vessel, but not less than two. The main fire pumps are located in the engine room below the waterline to ensure constant suction pressure. In this case, fire pumps must be able to receive water from at least two places. Tankers and some dry cargo ships have an additional emergency fire pump(APN). Its location depends on the design of the vessel. The APN is located outside the engine room, for example in a separate room in the bow of the ship or in the tiller room. It must be supplied with power from an emergency diesel generator.

End and ring fire systems

From fire pumps, water flows into a piping system that is laid throughout the ship. According to the type of pipeline system there are ring And end. Water is supplied through pipes to fire hydrants (fire horns - as they were previously called). Non-working parts of the fire hydrant, as well as the fire main on the open deck, are painted red. Each fire hydrant has a connecting nut to which the fire hose is connected. And the fire nozzle is connected directly to the hose.

Fire nuts.

Fire hoses.

Modern fire hoses are made of synthetic fibers that have good flexibility, do not fade in water and provide the necessary strength with low weight. Inside the sleeve there is a rubber coating that ensures tightness. The rubber layer is very thin, so it is easy to damage. It should be remembered that when supplying water to the hose, the fire valve must be opened slowly until the hose is filled with water. Then you can open the fire valve to full flow.

Fire hoses are stored in special boxes, double-rolled with trunks attached to them, and indoors and attached to fire hydrants. Length of fire hoses: on deck 20 m, in superstructure 10 m.

Fire hoses at both ends at a distance of 1 m from the connecting heads must be marked: number, name of the vessel, year the hose was put into operation.

Fire trunks.

The main fire trunks are:

· fire nozzles for spray jets;

· combined fire trunks.

You will find separate fire nozzles for compact and atomized water at coastal facilities.

Stationary fire monitors are also used on ships; they are usually installed on tankers, where due to high temperature it is impossible to get close to the fire.

On some ships they install fire sprinkler system indoors. On the pipelines of this system, which are laid under the ceiling of the protected premises, automatically operating sprinkler heads are installed (see figure). The sprinkler outlet is closed with a glass valve (ball), which is supported by three plates connected to each other with low-melting solder. When the temperature rises during a fire, the solder melts, the valve opens, and the escaping stream of water hits a special socket and sprays. In other types of sprinklers, the valve is held in place by a glass bulb filled with a highly volatile liquid. In the event of a fire, liquid vapors rupture the flask, causing the valve to open.

The opening temperature of sprinklers for residential and public premises, depending on the melting area, is 70-80 0 C.

To ensure automatic operation The sprinkler system must always be under pressure. The necessary pressure is created by the pneumatic tank with which the system is equipped. When the sprinkler is opened, the pressure in the system drops, as a result of which the sprinkler pump automatically turns on, which provides the system with water when extinguishing the fire. In emergency cases, the sprinkler pipeline can be connected to the water extinguishing system.

In the engine room for extinguishing oil products and the molar storeroom, where it is dangerous to enter due to the risk of explosion, water spray system. On the pipelines of this system, instead of automatically operating sprinkler heads, water sprayers are installed, the outlet of which is constantly open. Water sprayers begin to operate immediately after opening the shut-off valve on the supply pipeline.

Sprayed water is also used in irrigation systems and to create water curtains. Irrigation system used for irrigation of decks of oil tankers and bulkheads of rooms intended for storing explosives and flammable substances.

Water curtains act as fireproof bulkheads. Such curtains are used to equip closed decks of ferries with horizontally loading where it is impossible to install bulkheads. Fire doors can also be replaced with water curtains.

Promising is mist water system, in which water is sprayed to a fog-like state. Water is sprayed through spherical nozzles with a large number of outlet holes with a diameter of 1-3 mm. For better atomization, compressed air and a special emulsifier are added to the water.

Steam extinguishing system

It is currently believed that steam is not effective as a volumetric fire extinguishing agent, for the reason that a considerable amount of time may pass before the air is displaced from the atmosphere and the atmosphere is unable to support the combustion process. Steam should not be introduced into any location with a flammable atmosphere not involved in a fire due to the possibility of charge formation static electricity. However, steam can be effective in extinguishing a burnout on a flange or other similar components if it is applied from a fire nozzle directly to the flange or a leak from any joint or gas outlet or similar component.

You may encounter a steam extinguishing system on some ships, so you need to have an idea of ​​how it works.

The operation of the steam fire extinguishing system is based on the principle of creating an atmosphere in the room that does not support combustion. The main part of the system is the steam boiler. Most modern ships are motor ships and do not use steam. Steam boilers are installed, for example, on product tankers to heat cargo before unloading, and these boilers do not have high productivity, so steam is used only for extinguishing small compartments, such as fuel tanks. Modern steamships are gas carriers and LPG tankers with steam main engines and steam boilers high power, therefore, on such ships, the use of steam as a fire extinguishing agent is quite justified.

The steam extinguishing system on ships is carried out on a centralized basis. From the steam boiler, steam at a pressure of 0.6-0.8 MPa is supplied to the steam distribution box (manifold), from where separate pipelines made of steel pipes with a diameter of 20-40 mm are installed into each fuel tank. In a room with liquid fuel, steam is supplied to top part, which ensures free release of steam when the tank is filled to the maximum. On the pipelines of the steam extinguishing system, two narrow distinctive rings are painted silver-gray with a red warning ring between them.

On newly built river vessels, the steam extinguishing system is not used.

Foam extinguishing system

Foam extinguishing systems are the second most common on ships after water extinguishing systems. Almost all ships are equipped with it, with the exception of small ships.

Vessel foam extinguishing scheme

Foam is a very effective means of extinguishing class B fires, which is why all tankers are required to have a foam extinguishing system running throughout the vessel. On dry cargo ships, foam can only be supplied to certain spaces (mainly protecting machinery spaces).

The foam extinguishing system itself is powered by a water fire extinguishing system, so if the fire pumps are not working and water is not supplied through the pipelines, the foam extinguishing system will also not work.

The design of the foam extinguishing system is very simple. The main supply of foaming agent is stored in the foaming agent tank (tank), which is usually located outside the machine rooms. Low and medium expansion foam agents are used on ships. If it is necessary to mix different foaming agents, their compatibility must first be checked according to technical documents.

Water from the fire main enters the ejector through valve 1 (not to be confused with the injector). An ejector is a special pump that does not have a single moving part. The stream of water passes at high speed and creates a vacuum, as a result of which the foaming agent is sucked into the foam extinguishing line when valve 2 is open. In addition, valve 2 serves to regulate the flow of the foaming agent and obtain the required amount of foam. A mixture of water and foaming agent is created in the ejector, but no foam has yet formed. For example, if we pour liquid soap into water, then there will be no foam until we mix this solution with air. Further from the ejector, the water emulsion goes through pipelines to fire hydrants 3, to which fire hoses are connected. Unlike a water extinguishing system, in a foam extinguishing system, either a foam generator or a foam-air barrel is connected to the fire hoses. Fire hydrants of the foam extinguishing system are painted yellow.

If tap No. 2 is not opened, then water is supplied to the foam extinguishing system and fire nozzles can be connected to the fire hoses and the foam extinguishing system can be used as a regular water fire extinguishing system.

An additional tap leading from the water extinguishing system to the foam concentrate tank is used to flush it.

A foam generator and a foam-air barrel are necessary for mixing the water-foam solution and air. The foam generator itself consists of a housing, a spray nozzle with a fire nut for attaching a fire hose and a double metal mesh. When the foam generator operates, the water-foam solution leaving the sprayer hits a mesh with many cells. At the same time, air is sucked in from the atmosphere. The result is a large number of bubbles, like in children's soap bubbles.

Volumetric CO 2 extinguishing system

Currently one of the most common volumetric fire extinguishing systems. Proven to be highly effective compared to other systems. Simplicity of device and maintenance.

Carbon dioxide station

The carbon dioxide fire extinguishing system consists of a cylinder station; on some ships there may be several of these stations. Carbon dioxide is stored in cylinders and, when the shut-off valves are opened, is supplied to the ship's premises.

Carbon dioxide displaces oxygen from the combustion zone and thereby stops it, but the fire does not cool down, as when using a CO 2 fire extinguisher. With the help of CO 2 extinguishing, as a rule, the following premises are protected: MKO, cargo tanks on tankers, cargo holds on cargo ships, storerooms with flammable and combustible liquids. The system is not used when extinguishing fires in residential and office premises.

How to use the system:

1. Remove all people from the room where CO 2 extinguishing will be used.

2. Seal the room in which the fire occurred.

3. Give a signal to supply gas to the room.

4. Supply gas to the room.

5. Monitor the effectiveness of extinguishing by measuring the temperature in the compartment. The main indicator of system efficiency is temperature reduction.

6. After the temperature drops, you need to wait another hour, then ventilate the room and send a reconnaissance group dressed in firefighter gear. In the event of a fire in the holds, it is prohibited to open the socket until the shore fire brigade arrives at the nearest port.

Remember that the CO 2 extinguishing system is a one-time use, if you fail to extinguish the fire the first time, do not use the system again until you recharge the cylinders. Therefore, if it is not possible to seal the room, then there is no point in using carbon dioxide fire extinguishing. If the CO 2 extinguishing system is not effective, other systems must be used to extinguish the fire.

Stationary inert gas system (SIG).

Let's look at another system designed to prevent the threat of fire and based on the principles of carbon dioxide fire extinguishing. The tanker fleet has a system for supplying carbon dioxide to cargo tanks from the ship's operating boilers. Exhaust gases leaving the boiler enter a scrubber, a special device where they are cooled and cleaned from solid impurities using water. These gases are then fed into the cargo tanks and, displacing oxygen, create a non-flammable atmosphere in them. The oxygen level in the tanks is measured using stationary gas analyzers.

Liquid chemical fire extinguishing system