in recent years, some hotels, restaurants, shopping malls and supermarkets at home and abroad have not cleaned the oil fume pipes for a long time, which has caused excessive accumulation of oil dirt in the flue, and some have caused huge casualties and property losses. The catastrophic supermarket fire in Paraguay, which shocked China and foreign countries, was caused by the dust and dirt blocking the corner of the barbecue stove chimney in the dining area, which overheated the temperature in the chimney and led to the dust explosion between the ceiling and the roof. This paper will briefly analyze the causes of flue fire and seek preventive countermeasures.

1. Analysis of the causes of flue fire

From the material point of view, the chimneys and oil smoke extraction pipes in the kitchens of hotels and restaurants and large shopping malls and supermarkets are usually made of iron sheets or plexiglass, which are incombustible and have no fire danger. However, some hotels and restaurants have wrapped a layer of combustible materials outside the pipes made of incombustible materials in order to cool down and insulate themselves, which brings fire danger. In order to save costs, some small restaurants use composite boards to make chimneys and oil smoke pipes. These materials are combustible in themselves. Once the flames go up or the oil pan catches fire, they may be directly ignited, which is more dangerous.

Oil dirt is the main factor causing flue fire. Because of the viscosity of the soot, it can adhere to the chimney and the inner wall of the fume extraction pipeline to form oil dirt, especially where the pipeline has a bend, which is easier to adhere and accumulate. If it is not cleaned for a long time, the oil dirt will accumulate thicker and thicker and block the pipeline. Grease itself is combustible, which will burn in case of open fire or high temperature, and spread along the inner wall of the pipeline, leading to the expansion of the fire; After the oil dirt blocks the passage, it will not discharge the oil fume in time, which will cause the temperature in the chimney and the oil fume extraction pipeline to be too high, which will cause the oil dirt to spontaneously ignite or the combustible outer packaging material of the pipeline to burn and cause a fire.

In addition, some hotel kitchen operators have poor awareness of fire safety and a weak sense of responsibility, and they leave their posts when the fire is not off, the gas is off, the oil is off, or cooking with oil is burning. Once there is a fire, the flames can easily spread through chimneys and smoke extraction pipes.

2. Precautionary measures for flue fires

In hotels and restaurants with hotel kitchens, first of all, attention should be paid to the arrangement of chimneys and oil smoke extraction pipes, which cannot pass through flammable decoration materials; The materials for chimneys and oil smoke extraction pipelines should be incombustible materials themselves, and combustible materials cannot be outsourced.

Secondly, the oil fume hood should be scrubbed once a day after use to remove the oil dirt on that day; It should be thoroughly cleaned once every quarter, and the grease and other dirt attached and accumulated in it should be removed in time, so as to prevent the excessive accumulation of grease and dirt in the inner wall or bend of flue and oil smoke extraction pipeline from causing fire danger.

Third, improve the fire-fighting facilities and equipment in the hotel kitchen, complete fire alarm equipment, and monitor and alarm the fire in time; Add a gas fire extinguisher, so that gas can be injected into the flue to extinguish the fire at the beginning of the fire; Open sprinklers are set at the end of chimney and oil smoke extraction pipeline. Once a fire occurs in flue, open sprinklers immediately to prevent the fire from spreading.

fourthly, the hotel kitchen operators are often educated about fire safety, and the management system of using fire, electricity, gas and oil in the hotel kitchen is formulated, and the operation methods and procedures are standardized to prevent the fire from being caused by human negligence. At the same time, strengthen the implementation of the duty system for key parts, and minimize the probability of fire accidents caused by failure to clean the oil fume pipeline.

The fire department also warned that oil smoke pipes are particularly prone to fire in summer. Major hotels should remember to clean the oil fume pipes in time to prevent accidents.