High Temperature Dust Bag

High temperature dust bag is the core filtering element for industrial high-temperature flue gas dust removal, mainly used to capture dust particles in flue gas at temperatures of 200~400 ℃ (some special materials can withstand temperatures above 600 ℃). With the advantages of "good filtration accuracy, strong adaptability, and convenient operation and maintenance", it is widely used in high-temperature flue gas emission industries such as power, steel, non-ferrous metal smelting, and garbage incineration. It is a key equipment for achieving ultra-low industrial dust emissions (dust concentration ≤ 10mg/m ³).

1、 Core working principle: filtration and dust cleaning mechanism

High temperature dust removal bags are usually installed in the filter bag chamber of bag filters, and their dust removal process is divided into two cycle stages: "filtration" and "cleaning". The core is to use the physical interception, inertial collision, and diffusion effects of filter materials to achieve dust separation.

1. Filtering stage

When high-temperature dusty flue gas (such as boiler tail flue gas, steel sintering flue gas) enters the bag filter, the airflow passes through the filter bag (usually an external filter type, where the flue gas flows from the outside to the inside of the filter bag):

The dust particles in the flue gas are first intercepted by the fiber layer on the surface of the filter bag, forming a "dust initial layer";

As the filtration continues, the "initial layer of dust" gradually thickens and becomes the main filtration layer, further improving the filtration accuracy (able to capture finer dust particles with a particle size of 0.1 μ m or more);

The purified flue gas passes through the inside of the filter bag and is discharged through the air outlet. At this time, the dust is firmly trapped on the surface of the filter bag or in the "initial layer of dust".

2. Dust removal stage

When dust accumulates on the surface of the filter bag to a certain thickness (usually monitored by differential pressure in the dust collector, starting when the differential pressure reaches 1500-2500Pa), it will cause an increase in airflow resistance and a decrease in filtration efficiency. It is necessary to start the dust cleaning system to remove the dust:

Mainstream dust cleaning methods: including pulse jet cleaning (commonly used, by instantly blowing the filter bag with high-pressure air to vigorously vibrate and remove dust), mechanical vibration cleaning (suitable for low concentration dust), and back blowing cleaning (by deforming the filter bag with reverse airflow to remove dust);

After cleaning, the dust falls into the ash hopper at the bottom of the dust collector and is discharged through the ash discharge valve (which can be recycled or stabilized). The filter bag recovers its filtering ability and enters the next cycle.