What is electrostatic spinning of filter bag
For the filtration of industrial flue gas, the bag type dust collection technology is used, and the filtration efficiency can reach 99%. However, in order to further improve the filtration efficiency, the bottleneck is encountered, which fails to meet the strict requirements for industrial flue gas emission.
Based on this, at present, many universities, enterprises and scientific research institutes use electrostatic spinning technology to prepare nanofiber membranes, and through mature membrane covering technology, attach nanofiber membranes to the substrate filter materials to filter conventional particles+double effect filter media bags with electrostatic adsorption of fine particles, so as to improve the filtering efficiency;
A high-voltage electrostatic field is formed between the spinneret of the liquid feeding device and the grounded receiving device. This high-voltage electric field will form an instantaneous electrostatic difference between the spinneret and the receiving device, which will charge the high polymer solution or melt at the spinneret and overcome its viscoelasticity and surface tension to form charged hemispherical droplets at the spinneret. With the increase of voltage, the hemispherical droplets will be stretched into a cone at a certain angle, This is now known as the Taylor cone, with an angle of 49.5 °. When the electrostatic field force increases enough to overcome the surface tension of charged droplets, the cone is further stretched to form a continuous jet. In the process of electrospinning, the droplet usually has a certain static voltage and is in an electric field. Therefore, when the jet diameter continues to decrease, spirals, whips and splits will occur at the same time to finally form nano or submicron fibers. As the solvent volatilizes and the solute or melt solidifies, it finally falls on the receiving device to form fibers.
The nanofiber filter bag prepared by the utility model has the advantages of low resistance, high filtering efficiency, small pore diameter, high porosity, etc., and has good filtering effect. At the same time, the problems to be solved also exist: ① composite fastness of fiber membrane and base material needle felt; ② Mechanical properties of fiber membrane; ③ The best spinning process of the fiber membrane and the stability in the production process.