A Comprehensive Guide to Electrostatic Perpetrators

Electrostatic Precipitator, or Electronic Static Precipitator, is usually abbreviated as ESP. An ESP Precipitator is a device that removes particles (such as dust and smoke) from a gas stream by using electrostatic attraction. ESP device shapes air passages inside. Each air passage is passing through electrostatic charged poles or boards. Mixed air is to be ionized instantly, the dust and smoke carry negative charge and soon attract to the positive boards. Air, as a kind of molecules, with little weight, still get out, leave the solid particles (dust and smoke) stuck behind. So, the mixed air gets filtrated and purified. 

Electrostatic attraction or electrostatic force is the basic working principle enables electrostatic precipitator process the ESP filtration. If the two charges are different, with one being positive and one negative, then they will attract to each other. Air, including the mixed dust, smoke and oil droplet are charged with negative current when passing through the electric field. Charged particles such as dust, smoke and oil droplet turn attractive and bond to the boards with the opposite current. So, pure air is separated and vent out.

The working principle of electrostatic precipitator

A transformer rectifier is needed to supply high-voltage static electricity. The static electric field contains electrodes (usually in form of wires or rods), and their counterpart is the collection plates. Electrodes are negatively charged by the rectifier, while the collection plates or other surrounding structures are grounded (or positively charged). When this static electric field is being charged, a corona discharge effect is taking place. The corona effect is a phenomenon where the strong electric field ionizes the air around the electrode, creating a region of plasma. This happens when the electric field is strong enough to strip electrons from nearby air molecules, turning them into ions. The Corona effect can appear as a faint glow around the electrode under certain conditions. The electric field also is called corona discharge field.

Particles such as dust, smoke and oil fog mixed with air flow and go through the corona discharge field. The corona discharge continuously generates a supply of ions that attach to particles in the air flow, charging them as they pass through. Dust, smoke and oil fog attract to the collection board due to static attraction force draw them. Clean air vent out simultaneously as these particles stuck to the collection board. The ESP filtration works.

The ESP precipitator in different applications deal with different particles. The removal methods of the dirt are also different. 

Dust accumulates on the plates over time, forming a layer of dust. The ESP is designed to allow continuous collection while the system remains operational. As dust builds up, the efficiency of the ESP can remain high since the electric field still penetrates through the dust layer to attract new dust. 

Periodically, the ESP undergoes a process known as rapping or shaking to dislodge the accumulated dust from the collection plates. This is usually done mechanically by vibrating or striking the plates to cause the dust layer to fall into hoppers located below the ESP. Once in the hoppers, the dust can be collected for disposal or recycling, depending on the type of dust and industrial requirements.

Removing oily smoke from an Electrostatic Precipitator (ESP) is more challenging than handling dry dust because the oil particles can create a sticky, sometimes viscous layer on the collection plates, which is harder to dislodge. Kleanland solves this problem by using stainless steel plates or SS tubes as the particle collector, as they are durable and easier to clean when dealing with sticky residues. During normal operation, oily residues are in liquid form and they drop with gravity to the bottom of the device, where an drain and an oil tray being beneath for collecting the greasy oil. 

When the collection boards accumulate very thick dust or oil, and the filtration efficiency drops. Kleanland integrated self-cleaning system inside the ESP device. For ESP range hood, steam washing system can connect to the hood. Kleanland provides independent steam generator, complete tubing and programed controller for commercial kitchen. ESP kitchen hoods get cleaned periodically by automatic program and sustain their best performing characteristics. For in-duct ESP device, steam cleaning also available. Built-in spray washing with water or solvent added water also is Kleanland mature solution for in-duct ESP device and industrial ESP device.