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Insulation clothing and fire apparatus use knowledge
Fire insulation clothing is made of composite materials of fiber fabrics and aluminized films. Garments include tops, pants, gloves, hoods and caps, asbestos-free, double light, high strength, flame retardant, high temperature resistance, heat radiation resistance The advantages of wear-resistance, folding-resistance, and non-toxicity to the human body can effectively protect firefighters and high-temperature workers from flames and high-temperature burns. Insulation clothing is composed of multiple layers of fabrics such as the outer layer, thermal insulation layer and comfort layer. This combination of parts can be made into single or multiple layers. The outer layer of thermal insulation clothing should use metal foil surface material with reflected radiant heat.
Insulation suits can effectively ensure the inspection of the Fire Equipment Quality Supervision and Inspection Center of the fire brigade, and meet the requirements of GA88 “Performance Requirements and Test Methods for Fire Protection Insulation Productsâ€. Marine protective clothing is inspected by China Classification Society.
The working principle of positive pressure air breathing apparatus is that the compressed clean air stored in the gas cylinder is depressurized through a pressure reducer and then depressurized by a secondary pressure relief valve into a full face mask for the wearer to breathe.
The advantages of positive pressure air breathing apparatus are: using an open structure, exhaled gas is directly discharged into the atmosphere, and because of the large flow of air supply, the wearer feels more comfortable to breathe; using a positive pressure structure, the pressure inside the mask is always greater than the external atmospheric pressure Therefore, the external harmful gas can not invade the wearer's respiratory organs, the use of high safety factor; can be used repeatedly inflatable, the use of low cost. Therefore, firefighters and rescue personnel all prefer to use positive pressure air respirator positive pressure air breathing apparatus. The disadvantages are: the use of a short time, usually about 1 hour.
The positive pressure oxygen respirator works as follows: the gas exhaled by the wearer enters a clean can through a full-face mask, an exhalation hose, and an exhalation valve. The absorbent (Ca(OH)2) in the clean can will be contained in the gas. The carbon dioxide absorbs and the rest of the gas enters the airbag. In addition, the compressed oxygen stored in the gas cylinders enters the balloon through a high-pressure tube and a pressure reducer, and is mixed into an oxygen-containing gas. When the wearer inhales, the oxygen-containing gas passes from the balloon through the inspiratory valve, suction hose, and full face mask into the wearer's respiratory organ to complete a breathing cycle. In this process, because the exhalation valve and the inhalation valve are both one-way valves, it is ensured that the respiratory airflow always unidirectionally circulates. Chemical reaction type: Ca(OH)2 + CO2 → CaCO3 + H2O + Q positive pressure type oxygen breathing apparatus has the advantage of: the use of a longer time, usually about 4 hours; using positive pressure structure, the mask pressure is always greater than the outside atmosphere Pressure, so that outside harmful gas can not invade the wearer's respiratory organs, the use of high safety factor. Therefore, mine rescue workers like to use positive pressure oxygen breathing apparatus .
The disadvantage of positive pressure oxygen breathing apparatus is that it adopts a closed cycle, and the absorption of carbon dioxide generates a large amount of heat, so the breathing is uncomfortable; the user must possess certain professional knowledge and operating skills, because the absorbent and cooling must be installed before use. Ice; the use of high cost.