Fuel fired boiler flue gas

Flue gas treatment equipment is used to effectively treat toxic and harmful substances contained in flue gas to a specified concentration, while avoiding adverse phenomena such as corrosion or blockage of the equipment. Generally, the flue gas treatment equipment used in garbage incineration plants can be divided into two categories: dust removal equipment and acid gas removal equipment. Nowadays, with the increasing demand for environmental quality, most waste incineration plants have added activated carbon adsorption heavy metal equipment in their flue gas treatment processes.

The flue gas treatment equipment mainly includes flue gas desulfurization tower, flue gas scrubbing tower, absorption tower, absorption medium transmission pipeline network, chimney and flue, etc. It is mainly used in the power industry, chemical industry, coking industry, metallurgical industry, and manufacturing industry with self owned boilers.

The equipment for removing smoke and dust generally uses electrostatic precipitators or bag filters. The removal of acidic gases is generally achieved by using a scrubbing tower to remove gases such as SO2 and HCI below the specified concentration. As for NOx, although its content in flue gas is not high, even if it is directly emitted without treatment, it generally does not exceed the requirements of environmental standards. But with the increasingly strict requirements for environmental quality in recent years, some waste incineration plants have also adopted measures to suppress the production of NOx.

dust collector

In order to meet the emission standards for particulate matter, the dust collectors used in waste incineration facilities are usually three types: cyclone dust collectors, bag filters, and electrostatic precipitators.

(1) Cyclone dust collector uses the centrifugal force and gravity settling effect generated by forced vortex to remove particulate pollutants from exhaust gas. The purification efficiency of cyclone dust collector is about 65%~80%, which is effective for granular pollutants above 10 μ m, and less effective for pollutants below 10 μ m. Cyclone dust collectors suffer from significant energy loss and are prone to corrosion due to the high-speed flow of flue gas. Large scale garbage incineration plants can use cyclone dust collectors as primary dust collectors.

(2) Bag filter is a type of dust collector that allows flue gas to pass through a filter bag, allowing particulate pollutants to adhere to the filter layer. It then periodically removes the particulate pollutants attached to the filter bag through vibration, airflow backwashing, or pulse flushing. The dust removal effect is related to the flow rate, temperature, moisture content, dust content, and filter material of the flue gas, and its efficiency can generally reach over 90%.

(3) Electrostatic precipitator

Electrostatic precipitator uses high-voltage negative electrode to generate corona effect, releasing electrons to ionize the passing flue gas, and the dust particles in the flue gas form charges, which are adsorbed and neutralized by the positive electrode plate of the precipitator. After a suitable period of time, hammer the electrode plate to lift the dust particles attached to it into the dust collection funnel. The dust removal effect of electrostatic precipitators is related to flue gas flow rate, dust particle size distribution, cohesiveness, specific resistance, electrode plate distance, voltage, current, etc., and can generally reach over 90%.

Acid gas removal equipment

Equipment for removing sulfur oxides and HCl: dry scrubbing tower, semi dry scrubbing tower, wet scrubbing tower.

Nitrogen oxide removal equipment: wet method, dry method, combustion control method.

The equipment for removing smoke and dust generally uses electrostatic precipitators or bag filters. The removal of acidic gases is generally achieved by using a scrubbing tower to remove gases such as SO2 and HCI below the specified concentration. As for NOx, although its content in flue gas is not high, even if it is directly emitted without treatment, it generally does not exceed the requirements of environmental standards. But with the increasingly strict requirements for environmental quality in recent years, some waste incineration plants have also adopted measures to suppress the production of NOx.