The Cause Of The Fire Of The Cartridge Dust Collector

The dust removal effect of the filter cartridge type dust collector is significant in use, but the shot blasting unit is easy to catch fire in the filter cartridge type dust collector during use, causing a large economic loss. The specific analysis of the cause of the fire mainly includes the following:

(1) Rust dust is a secondary flammable solid, and its ignition point and ignition energy are both low. If the average particle size of rust dust is 100-150um, the ignition temperature range is 240-439 ℃, which is much lower than its melting temperature. The flammability of dust is related to various factors such as particle size, composition, concentration, combustion heat and combustion speed. The smaller the particle size, the larger the surface area and the easier it is to ignite.

(2) The external hot objects are sucked into the dust collector. The hot particles outside the fire are sucked into the dust collector, igniting the rust dust inside, causing the flammable filter cartridge to ignite and burn. The spark spark temperature generated by electric welding and gas cutting reaches hundreds of degrees, and it is easy to ignite rust dust. The speed of the impeller of the shot blasting machine used in the shot blasting machine is generally 2250f / min, and the blasting speed is greater than 80m / s. When the high-speed steel shot hits the steel plate, it may also generate hot particles or sparks that are drawn into the dust collector and cause a fire.

(3) The temperature inside the cartridge of the shot blasting machine is high. The temperature of the steel plate that causes natural fire to enter the shot blasting machine is generally controlled within 80 ℃. The total power of a single shot blasting machine is generally tens to hundreds of kilowatts. Most of the mechanical energy will be converted into heat energy. During operation, the temperature of the system will gradually increase. At the same time, the material is converted into dust, the specific surface area is increased, and the activity of the substance is increased. Under the condition of being combustible, the flammable dust oxidation exothermic reaction rate exceeds its heat dissipation capacity, and it is finally converted into combustion called dust nature. The finer the dust, the easier it is to be natural.

(4) Static electricity causes fire. Rust dust will generate static electricity in high-speed airflow. Due to natural radiation, ion or electron adhesion, friction between dust particles or between dust and objects usually makes the dust particles charged. When the rust dust flows in the pipeline, it rubs itself. The friction between the dust particles and the inner wall of the pipeline and equipment can generate an electrostatic potential of thousands of volts. At the same time, this dust electrostatic has the characteristics of dispersibility and suspension, and the dispersion increases the friction. The area and suspendability make the rust particles contact but not continuous, which leads to higher and higher electrostatic potential.

(5) Another possible reason is that the design of the dust collector of the shot blasting machine itself is unreasonable, and this cannot be solved. Only the manufacturer can be asked to re-make a dust collector to match its own shot blasting machine.