Detailed Explanation of Positive Pressure Air Breathing Apparatus

The respirator is a self-sufficient open-type respiratory protective device. According to the pressure conditions inside the mask during use, respirators are divided into negative pressure air respirators and positive pressure air respirators. Currently, almost all fire brigades in our country are equipped with positive pressure fire air respirators. Let's take a closer look at the details of positive pressure air respirators!

The respirator is a self-contained open-type respiratory protective device. According to the pressure conditions inside the mask during use, it is divided into negative pressure air respirators andpositive pressure air respirators, currently, almost all fire brigades in our country are equipped with positive pressure fire air respirators. Let's learn about the details of positive pressure air respirators!

Thispositive pressure air respiratorsutilizes the mask to closely fit around the wearer's face, completely isolating the wearer's respiratory organs, eyes, and face from toxic air or oxygen-deficient environments, providing clean air for the wearer to breathe from a compressed air source, with exhaled gas directly discharged into the atmosphere. In any breathing cycle, the pressure inside the mask is greater than the ambient pressure.

1. Structure:

The respirator mainly consists of a mask assembly, air supply valve assembly, pressure reducer assembly, back frame assembly, empty bottle assembly, and pressure indicating device.

1. Mask assembly

The rubber of the mask assembly is made from a mixture of natural rubber and silicone rubber.

2. Air supply valve assembly

The air valve assembly is installed on the mask to supply air into the mask. Even if the flow rate of the air supply valve reaches 500L/min, it will maintain a pressure greater than the ambient atmospheric pressure to meet the user's needs. A plug is installed on the medium pressure pipe of the air valve, connected to the quick connector of the medium pressure pipe.

3. Positive pressure air respirator pressure reducer assembly

The purpose of the pressure reducer is to ensure the normal operation of the air supply valve. This air respirator uses a constant pressure reducer. If the pressure reducer causes the medium pressure to rise for some reason, the medium pressure safety valve will automatically open, ensuring the safety of the medium pressure pipeline and air supply valve. The medium pressure pipe delivers the medium pressure gas of 0.6~0.9MPa output after reduction to the air supply valve. When the pressure in the gas cylinder drops to 5.50.5MPa, the alarm will sound to notify the user to seek refuge in a safe place.

4. Gas cylinder assembly valve assembly

The air respirator uses a carbon fiber composite gas cylinder, made by winding high-strength fibers such as fiberglass around the outer periphery of an aluminum alloy liner. The rated storage pressure is 30MPa. The gas cylinder valve is equipped with a pressure protection membrane. When the pressure inside the gas cylinder exceeds about 25% of the rated pressure, the safety membrane on the gas cylinder valve will burst, safely releasing the pressure from the gas cylinder to ensure safe use. The gas cylinder valve used in the gas cylinder assembly is a self-locking valve, which can prevent accidental closure after the valve is opened.

2. Positive pressure air respirator back frame assembly

The back frame assembly consists of a back frame body, shoulder straps, waist belt, waist contact piece, and bottle strap to secure the gas cylinder assembly and pressure reducer assembly. The back frame body is shaped to fit the physiological characteristics of the human back and hips, distributing the weight of the equipment mainly on the hips, enhancing the mobility of the wearer's shoulders and hands.

Pressure display device

The pressure gauge connection pipe uses high technology and fluorescent display, allowing easy observation of pressure values even under high pressure. It is externally protected by a rubber cover to prevent damage to the pressure gauge from impacts. It uses medium pressure alarms with low gas consumption, and the alarm level is greater than 92db(a).

3. Working principle

The operating temperature is -30~60. It is a structure where, after opening the valve of the gas cylinder, the high-pressure air inside the gas cylinder enters the pressure reducer assembly through the bottle, while the pressure display device shows the reading of the air pressure inside the gas cylinder. When the user wears the mask and inhales, a negative pressure is generated, while the positive pressure spring moves the large diaphragm down, pressing the opening rod to disengage it from the locking device, opening the air supply valve flap to supply air to the user. During exhalation, the exhalation valve of the mask opens, allowing the exhaled gas to be discharged outside the mask. When exhalation stops, the exhalation valve of the mask closes, preparing for the next inhalation.

4.positive pressure air respiratorsUsage

1. Check the pressure of the gas cylinder and the airtightness of the system. 2. Test the alarm and pressure display device. 3. Check if the hoop strap is secured. 4. Wear the orthosis. 5. Secure the shoulder straps. 6. Wear the mask. 7. Check the airtightness of the mask. 8. Open the bottle. 9. Check the breathing performance of the equipment. 10. End of use.

5. Equipment maintenance

The air respirator should be cleaned and disinfected after use at least once a month, with careful inspection of each component. The air storage pressure of the air cylinder should be checked at least once a week. The structure of the air respirator should be intact, all components should be securely installed, and the empty alarm of the gas cylinder should not alarm under the specified residual pressure. If there are leaks (referring to the overflow valve) that cannot open or close normally, or if the air supply valve cannot open or close normally, or if other operational faults are found, do not use the air respirator.

The above is a detailed explanation of the positive pressure air respirator. Our company also operates safety helmets,positive pressure air respiratorschemical protective clothing, protective clothing, thermal insulation clothing, and other products. If you need to know more, feel free to contact us!