Oxygen breathing apparatus Safe operating procedures for breathing apparatus

Firefighters in the fire rescue, in addition to prevent the flame of the barbecue, but also to prevent the smoke of asphyxiation poisoning. In modern buildings, many decoration materials are made of flammable and flammable substances, such as plastic wallpaper, chemical fiber flooring, polystyrene foam board, polyurethane foam plastic, artificial polaroid board and so on. The surface of these decoration materials is often coated with a large number of paint-like substances. Therefore, under combustion or high temperature pyrolysis, a large number of toxic fumes and gases will be produced. Such as gasification carbon, hydrocyanic acid, acrolein, hydrogen chloride, particulate carbon, etc., great harm to people. If the fire site is a productive building, there are productive poisons, or there are explosive gases, the fire site is more dangerous.

For example, on March 7, 1997, a fire broke out in a factory in Nanjing because a student at the children's school used a lighter to burn a bandaged rope while playing with it, igniting the plastic foam. At that time, the smoke was thick, the gas was thick and the smell was strong. Because the firefighters did not wear gas masks, more than 40 trains and related fire personnel could not get close to the fire scene, and could not identify the fire situation. In the face of the fire poison smoke helpless, had to stay away from the fire, helplessly watching the fire swallowing modern production lines. How sad!

According to relevant data, when the concentration of carbon monoxide in the air is 0.5%, people will die after 20 minutes; When the concentration is 1%, people will lose consciousness after only a few mouthfuls, and will be seriously poisoned and even die after 1 to 2 minutes. In the general fire smoke, the concentration of carbon monoxide can reach 4~5%, and the maximum can reach about 10%. Hydrocyanic acid gas is more toxic, can make people "lightning poisoning" and death. Japanese and British investigations into the deaths of nearly 2,000 people in the fires concluded that the ratio of smoke poisoning to death was close to 1:1. The textbook "Smoke Control and Exhaust Engineering" of the fire department of the Armed Police Technical College of China clearly points out that the number of people killed by smoke directly accounts for 1/3 to 2/3 of the total number of people killed by fire.

According to other data, there is a direct relationship between human breathing volume and labor intensity. A person walking at a normal speed of 3 to 3.5 kilometers per hour has a lung capacity of 25 liters; When running at 10-12 kilometers per hour, the lung capacity reaches 64 liters; When carrying 12-15 kg load and heavy labor, the lung capacity can reach 75 liters. It can be seen that when firefighters rescue the fire scene, they should carry fire equipment, grab valuable materials, and carry the injured, and their lung capacity is of course greater than 75 liters. This accelerates the inhalation of harmful gases by firefighters, accelerating the process of poisoning. Therefore, at present, many full-time or part-time fire personnel have fully understood the important role of gas masks - oxygen respirators in the fire rescue process, and are equipped with or are equipped with oxygen respirators.

The circulating positive pressure oxygen respirator (hereinafter referred to as the respirator) is more suitable for the self-protection of firefighters in fire places. The device includes a smaller compressed oxygen cylinder, pressure reducing valve, regulator valve, breathing pack, mask and a chemical purification tank that removes carbon dioxide from exhalation. When used, in the circulation loop, the positive pressure is always maintained, the external gas cannot enter the system, the carbon dioxide in the breath is absorbed by the purifying agent calcium hydroxide in the purification tank, the remaining gas is returned to the breathing package for inspiratory use, and the consumed oxygen is supplemented by the high-pressure oxygen cylinder to the circulation loop. In addition to the effective prevention of various toxic gases and particulate carbon in the smoke, the respirator can also protect the head, eyes and mucous membranes from the strong stimulation of the smoke and the damage of the flying sparks and high temperature gas waves. Therefore, breathing apparatus is an indispensable and important equipment in modern fire fighting work.

However, the breathing apparatus is used as a backup fire equipment, which is often idle, and the opportunity to use it is even less for part-time firefighters in the enterprise. But in the event of a fire, breathing apparatus will come in very important. If the management is not good, do not pay attention to maintenance, the ventilator loses its proper function, or the user uses it improperly, or even does not use it at all, how can it play its role in a crisis? The result is that the rescue failed to save, their own lives were on the tower, a number of fresh lives will be buried, this is how painful things ah!

This is not shocking. For example, on June 1, 1995, a death accident occurred in the fourth branch plant of Sichuan Changshou Chemical Complex. At that time, the death of the accident put on a respirator to save people at the scene, because they were not familiar with the safe operation procedures, the oxygen bottle valve was not opened when using, so that the system had no air source, resulting in hypoxia and suffocation. In recent years, Guangdong, Sichuan, Shaanxi, Jiangsu and other places have also occurred a number of accidents due to improper storage of respirators, failure in use, resulting in the death of ambulance workers in the rescue. It can be seen that managing the respirator well is an important guarantee to ensure the safety of the ambulance in the fire place.

First, improve the management system of breathing apparatus, strengthen maintenance and operation training

1. Establish a management account of respirators, implement a one-card system, and number them one by one. The contents of the account are:

(1) Responsibility to the person, regular maintenance. Such as regularly filling oxygen, replacing absorbent, testing valve integrity, etc., to clarify the responsible person, to avoid irresponsible human errors in the work.

(2) Establish inspection, overhaul and maintenance records. The records should reflect the inspection time, detected problems, maintenance status, acceptance status, maintenance content, etc. These facts must be understood and unambiguous.

2. In order to ensure that the respirator is in a state of emergency at any time, it is necessary to ensure that the various components of the respirator are in good condition, and the specific requirements are:

(1) Requirements for storage locations of respirators. The respirator should be stored in a place where there is no direct sunlight, no grease, no dust, no corrosive acid gas, and the distance from the open flame is greater than 10m. It shall not be stored in cabinets that cannot be seen directly, nor shall it be locked to ensure that it is readily available for use in emergencies.

(2) Check the oxygen cylinder pressure regularly. When the pressure is found to be lower than 7.8MPa (80kgf/cm square), it must be oxygenated in time (take the AHG-2 oxygen respirator produced by Chongqing Coal Mine Safety Instrument Factory as an example, the same below).

(3) After each use (including exercises), it is required to conduct a comprehensive inspection and cleaning, and quickly restore the use of the function, and take timely measures to find problems. The specific contents are:

a. The oxygen cylinder must be re-inflated;

b. Calcium hydroxide absorbers must be replaced;

c. Masks, breathing hoses and shells must be cleaned and disinfected

d. It is necessary to check whether the parts are damaged and whether the sealing degree of the joint gaskets is good.

3. Conduct basic operation training for fire personnel. All fire personnel must learn the basic knowledge and skills of operating procedures, carrying methods, troubleshooting simple faults, etc. :

(1) Carry out actual operation training in accordance with the operating procedures of the "Oxygen respirator Safety Operating Regulations", and conduct assessment, and allow to use after meeting the requirements.

(2) Rehearsal training for the use of respirators should be conducted once a year. If a fire or gas leak occurs in a certain work place, the field rescue and disaster relief exercises are carried out to achieve the purpose of not chaos, proper command, orderly and effective rescue coordination.

4. Regular physical examination of fire personnel, found to be suffering from heart disease, hypertension patients must be transferred from the post, in order to improve the physical quality and combat effectiveness of fire personnel.

5. The maintenance and use of the respirator should be regularly checked and assessed, which can be linked to economic benefits such as bonuses, to ensure the implementation of responsibilities and measures, and to ensure that the respirator is always in a state of emergency.

6. When using breathing apparatus for fire rescue, it must be stipulated that more than two people cooperate, monitor each other, allow contact through gestures, signals, writing or other means, it is strictly prohibited to take off the mask to speak in the fire, and it is strictly prohibited to act alone.

Second, breathing apparatus safety operating procedures, focusing on safety and practical and familiar with performance

1. The movement of wearing respirator should be standardized. The wear mode is left strap, that is, the strap is hung on the right shoulder and the respirator is placed on the left waist. The reasons for this consideration are: first, most people are right-handed, and the respirator placed on the left waist does not affect the operation of the right hand; Second, the cylinder valve is in front of the body, easy to operate; Third, it is easy to observe the pressure gauge, once found that the pressure is not enough, you can quickly stop the rescue and evacuate the fire.

2. It is required to open the oxygen cylinder valve and check the oxygen pressure before wearing the respirator. It can be used only when the pressure is higher than 7.8MPa. Prevent the pressure is too low, the oxygen supply time is not long, affecting the rescue work.

3. Specify the operation method of wearing the mask: lift the mask, thumb outside, the other four fingers inside, put the inner cover up from the lower jaw, cover the face, and then take several deep breaths to experience whether the various parts of the respirator are good. Only when there is no problem can you enter the fire scene.

4. The change of oxygen pressure should be observed at any time during use, and when the pressure is found to drop to 2.9MPa, the fire personnel should quickly exit the fire site. This is because the fire danger and the safety zone generally have a certain distance, and it is too late to retreat when the oxygen is used up, so we must leave enough oxygen margin.

5. In use, if you feel dull and sour at the same time, this is the cause of excessive accumulation of exhaust gas in the air bag. You can press the manual supply button to open the automatic supply valve and replenish oxygen. If the time interval between two press the manual recharge button is too short, that is, the accumulation of exhaust gas in the air bag is too fast, which is due to the failure of calcium hydroxide absorber, the fire danger area should be evacuated as soon as possible.

6. In use, if the pressure reducing valve quantitative oxygen supply failure occurs and you have a serious feeling of tightness, you should press the manual supply button, quickly withdraw from the fire place, replace the respirator and then enter the danger area.

7. It should be stipulated that during use, direct contact with oil or fire should be avoided, and impact should be prevented to prevent the explosion of the respirator.

Breathing apparatus is an indispensable protective device to protect the safety of firefighters in the fire scene rescue. We must not only strive to equip, but also strengthen management and operational training to ensure that it can fully play its function when it is used. This article is the author found in the process of practice and work experience, imagine to provide reference for the fire department, especially the enterprise part-time fire brigade, so that the breathing apparatus in the fire work to better play its role.