Protecting the environment. Investigating the electrostimulation process with fabric filtration

Abstract

In the industrial purification of gases in metallurgical enterprises and in particular in refractories, sleeve filters are being widely used.They are being increasingly used since fabric filtration ensures a high degree of purification of the gases with comparatively small sizes of equipment, and also the most direct means of using the extracted dust. Also, industrial filtration of gases uses a lot of energy and consumes many filter materilas, which makes the process costly.Increasing the effectiveness of fabric filtration gives undoubted social and economic benefits.One of the most probable ways of doing this is to use electrostatic factors.The methods and results of the influence of electrostimulation are widely reflected in foreign publi-The positive influence of changing the dust using a friction effect on the efficiency of fabric filtration was noted in [4]. It is clear that the best result can be obtained by using an external electric field.In the first stage of the study we investigated the electrostatic characteristics of the electrode-fabric system.The fabric was stretched on the surface of the electrode, consisting of a metal netting, and secured between flange.The electrode was supported with a high-voltage (up to 6.5 kV) supply using a universal supply source UIP-MI0.The electrical potential developing on the surface of the fabric is considered in relation to the magnitude of the strength of the electric field created on its surface.The size of the voltage in the field is determined by the electrostatic flux method E-ESP [5].The results of determining the electric potentials on the electrode and on the fabrics placed in the electrode are shown in Table I. Most fabrics are capable of increasing the total potential of the electrode-fabric system, which is probably a consequence of polarization of the molecules of the polymer materials.The effect of reducing the potential is noted in the felt and cloth materials in view of their density and thickness.It should also be noted that when the electrode is supplied with a positive potential the total electric potential in the system is somewhat higher than for a negative.This may be explained by the shorter time of the leakage of negative charges [6]. As a whole the results of this series of experiments suggest that it is possible to induce electric charges on the filtering surface.The influence of electrostimulation on the effectiveness of filtration was studied on an aerodynamic rig, consisting of a section of a gas duct equipped with a dust generating unit, a fan, a device for securing the filter screens, and control instruments for the velocity of the air flow, dust content, voltage of the field created by the current of dust laden aerosol [7].The effectiveness of filtration is influenced by the charging of the dust particles. The particles in the flow after generation are normally charged both positively and negatively, but some sign of the charge nevertheless predominates.The main characteristic of the electric charging of the aerosol is taken as the spe...