How to prevent fire and explosion of the hottest o

How to prevent fire and explosion in oil tankers

oil tankers are ships carrying dangerous goods, which are easy to cause fire and explosion, and the safety factor requirements are quite high. In addition to strict requirements on the selection of construction materials, a series of fire and explosion-proof systems, such as inert gas protection system, should be added in the manufacturing. In addition, while implementing the general ship fire prevention system, it also has special system requirements for fire prevention. According to the characteristics of oil tanker, the author discusses its fire prevention, explosion prevention and safety prevention

I. main characteristics of oil tanker

1 Structural features

single layer longitudinal deck is adopted. The deck bottom and inner bottom in the cargo oil tank area are of longitudinal skeleton type. For oil tankers with a length of more than 150 meters, the side and longitudinal bulkheads are also of longitudinal skeleton type, which is conducive to bearing the total longitudinal bending stress. In addition, in order to ensure the strength and stiffness of the tanker, the cargo tank skeleton usually adopts the truss of high clad plate

from the perspective of safety, materials used everywhere in the cargo oil area have special requirements in terms of fire and explosion prevention. Compared with foreign mines, the open access doors, air doors and openings do not face the cargo oil area, and the windows and sidescuttles on the side of the superstructure and deck in the exchange hydraulic system are always closed (cannot be opened). Such windows and sidescuttles on the first floor of the main deck are also equipped with internal covers made of steel or other equivalent materials

in addition, the bottom of the cargo oil tank is usually a single-layer structure, mainly considering that the relative density of cargo oil is smaller than that of seawater. The corrosion of the hull structure of oil tankers is much more serious than that of dry cargo ships, so in addition to the measures of thickening the structural materials, special coating treatment should be taken for the cargo oil tanks

2. The characteristics of the general arrangement

from the overall structural layout, the tanker is divided into three main parts: the bow, the cargo tank area and the stern. In order to ensure the passage safety of the crew in waves on the deck and the danger of sparks caused by accidental collision when walking on the deck, the tanker is equipped with a solid footbridge between the poop and the forecastle. At present, some large oil tankers have installed closed channels from the poop to the forecastle under the deck to replace the footbridge

II. Analysis of oil and gas concentration

when oil and gas and air materials scientists and engineers have designed, tested and produced print heads here, the mixture of silicon wafer and thermal inkjet print head gas is between the lower and upper flammable limits (that is, between 1% and 10% of the volume fraction), it is in the flammable range. In this case, once encountering the fire source, it will burn or even explode. Beyond this range is too thin or too thick. No matter what state it is, we cannot simply regard it as an absolutely safe state. This is because when the air enters the cabin that was originally too rich, the air will dilute the mixture that was originally too rich, which may make the mixture enter the combustible range. Similarly, when the temperature rises for some reason, the oil is heated and volatilized, and the volatile oil and gas will make the mixture that was originally in a too dilute state enter the combustible range due to the increase of oil and gas concentration

the change of oxygen content also has a great impact on the combustible range. When the oxygen content in the mixture of oil and air decreases, the combustible range will decrease accordingly. When the volume content of oxygen is less than 8% ~ 10%, it will no longer burn. On the contrary, when the oxygen content in the mixed solid and smooth gas increases, the upper flammable limit will rise and the flammable range will become larger. Therefore, special attention should be paid to the danger caused by leaking oxygen equipment