Preparation of pulverized coal for fire treatment in cement plantDate: 2019-06-13 Views:
With the increasing emphasis on environmental protection, energy saving and emission reduction, electric bag conversion or electric bag combination has become an inevitable trend of coal powder preparation technology in the cement industry in the future, but the ensuing powder ignition and dust explosion has become a very headache for many enterprises.
Although many cement enterprises use carbon dioxide fire extinguishing equipment, but still frequent fire, the root cause is still not found in the first time fire.
Unreasonable detection point setting:
Most of the time, the design and installation are completed by fire engineering company or fire equipment factory.
There is a serious problem here, no matter fire engineering companies or fire equipment manufacturers, many designers know little about the coal powder preparation process, or even know nothing, a fire designer who does not know the cement industry to design the cement industry fire protection, its design rationality can be imagined.
Below, the main ignition point of the whole production line is analyzed from the whole coal powder preparation process (original coal bin -- mill -- powder separator -- dust collector -- mill).
Cloth bag dust collector:in the whole process of fire prevention, cloth bag dust collector is very critical and easy to catch fire, especially after long-term accumulation of dust in the dust bucket, it is easy to cause the whole dust collector to catch fire due to the nature of pulverized coal. The fire prevention of cloth bag dust collector is very important in the whole preparation of pulverized coal.
In order to find the fire at the first time, the fire detector must be reasonably placed. According to the author's large amount of engineering experience in the cement industry in recent years, it is better to install the fire detector (usually thermocouple or thermal resistance) in the position above 2/3 of the ash bucket.
Advantages:1) reasonable avoid access;
2) once the fire is caused by pulverized coal, it can be found in the first time;
3) the constant temperature of coal dust flow can be detected to prevent the coal dust from entering the coal dust bin through the screw machine.
According to the characteristics of pulverized coal fire, the following problems and Suggestions for modification are put forward for general fire design:
Unreasonable setting of carbon dioxide spray point:
Mill: when the author remold the original co 2 fire extinguishing system in many waterworks, it is found that many co 2 fire extinguishing systems seldom consider the mill inlet and body fire, which is very unreasonable.
Once the mill catches fire and is not controlled, the pulverized coal will easily enter the dust collector along with the negative pressure air stream, causing the dust collector to catch fire.
Coal dust bin: coal dust bin spray point layout is not reasonable, but also cement plant: carbon dioxide fire extinguishing common problems, many manufacturers will carbon dioxide gas pipeline at will and the diversion pipe connection, does not play the role of inhibiting fire.
Inadequate preventive measures:
From the fire fighting concept, fire prevention is more important than fire fighting, many cement plant section long in coal dust warehouse temperature overtemperature, such as no detection of fire, generally will not be timely treatment, but let nature take its course.
Mental paralysis is an important cause of fire from small to large.
Once the temperature of pulverized coal warehouse exceeds 80C, 2-3 bottles of carbon dioxide should be opened immediately to protect the air dilution inside the warehouse and play the role of prevention in advance.
On the basis of the original fire fighting pipes, two sets of temporary carbon dioxide spraying interfaces are added. During the suspension of the kiln, 1-2 bottles of carbon dioxide agents are sprayed from the spraying interface to play the role of prevention in advance.