Application of bag filter dust collector in flue gas purification system of waste incineration

Waste incineration technology with complete garbage disposal, and has the energy to provide energy and recovery of scrap metal and other benefits, it can achieve garbage harmless, reduction, and resource purposes. However, due to the harmful and toxic fumes produced after incineration, the purification process must be strictly implemented.

Waste incineration flue gas purification process

At present, the MSW incinerator flue gas purification mostly dry and semi-dry purification process. Semi-dry purification process is to add basic reactants in liquid form, the reaction product of the solid form collected in solid form, the combination of the form is generally "spray reactor bag filter." Semi-dry process can not only achieve higher pollutant purification efficiency, relative to the wet process is simple, no waste water needs to be handled, the investment and operating costs are lower, and its application in the world is more common.

Waste incineration flue gas characteristics

1. Flue gas moisture content. This is because the amount of water originally contained in domestic waste is large and some hydrocarbons are also produced during combustion. The average moisture content of 23 to 30%.

2. Due to the complexity of the trash components, toxic and harmful components are also contained in the dust generated after combustion, including trace metals such as mercury, cadmium, lead, molybdenum, chromium, nickel and copper. And the resulting particle size is also smaller, higher viscosity.

3. Fumes composition is also complex. Unlike coal-fired boilers, it contains not only O2, SOx, CO2, NOx, but also acid gases such as HCl and HF, water vapor and total hydrocarbons (THC). This must be carefully studied and considered when selecting the filter media.

4. As the carcinogenic substances such as dioxins and furans may also be produced during combustion, which are extremely harmful to the human body. Generally before the bag filter is injected into the activated carbon adsorption, which should also be noted.

5. The dust particle size is fine and the viscosity is high.

It can be seen from the above characteristics, domestic waste incineration flue gas purification and dust removal is both very difficult and very important.

About bag filter dust collector selection

1. Bag filter dust collector cleaning methods to determine

Baghouse dust cleaning methods commonly used have back blow, vibration and pulse cleaning method. Back blow, vibration cleaning method, low energy consumption, but the general selection of filtration speed than pulse cleaning method is also about half lower, resulting in a large area, increase the initial investment costs.

In the dust collection efficiency, the difference between the two is not large. This is because the layer of dust on the filter material is not easily "over-cleaned", and the problem that often occurs in garbage incineration is poor cleaning, which means that the dust on the filter bag is not clear and leads to resistance Increasing.

Bag filter dust collector on the waste incinerator is best to use sub-chamber structure. This facilitates maintenance without affecting the operation of the incinerator. And sub-room can be used after the three-state cleaning method to improve the cleaning effect.

In the use of pulse bag filter, we generally use the injection pressure of 4.5 ~ 6.5kg / cm2.

2. Bag filter dust collector to determine

(1) Correctly determine the amount of flue gas combustion.

Because bag filter dust collector size depends on the size of the filter, but it is difficult to determine changes. If the estimation of flue gas is small, the actual filtration speed is large, resulting in large equipment resistance and poor cleaning. It is difficult to run continuously for a long time. However, when the estimation is large, the initial investment of the equipment is high, but there is no problem in operation.

(2) Choice of filter bag material.

According to the nature of smoke and smoke composition to choose the right filter. The choice of filter is the key, if the filter is not suitable, the service life is affected, and the cost of replacing the filter is not cheap.

The filter material to consider the following factors: temperature, acid, alkali, oxidation resistance; In addition, due to the high humidity of waste incineration flue gas, hydrolysis resistance is also a factor that must be considered when selecting the filter media. Due to the different bag material prices vary greatly, so the final choice is often a one-time investment and operating costs and results of comprehensive consideration of the results. Different media temperature, dust removal efficiency, cleaning performance, costs and different chemical composition of the flue gas corrosion resistance are not the same, need to be considered.

The general options are: glass fiber filter, Teflon, Ryton, P84, Gore-tex and so on. Ryton filter material is resistant to acid, hydrolysis, abrasion resistance are good, the price is not too expensive, as long as the flue gas oxygen content is less than its tolerance (different temperature tolerance oxygen content is different ), You can achieve good results. P84's dust catching effect is better than Ryton, but hydrolysis resistance than Ryton. Goodrtax good performance, but the higher the price, Teflon acid, alkali and other properties, but expensive. Fiberglass cloth can not filter HF-containing gas, but the price is more appropriate.

(3) Pay attention to the flue gas acid dew point.

When the flue gas temperature is lower than the acid dew point, the acid generated by condensation will corrode the equipment and create soot on the filter material. Therefore, to take some measures on the dust removal system, such as hopper heating, hot air circulation, pipeline bypass, equipment insulation, flue gas heating.

(4) Pay attention to choose well-made equipment.

In particular, pulse injection system components, components, the inspection door, the ash, Ash device, filter bag and flower plate with the design and processing of filter bag cage quality (finish and perpendicularity, etc.) are better, Otherwise it will affect the long-term good operation of the equipment.

Tianjin Sino International Trading Co., Ltd. is a comprehensive environmental pollution control high-tech enterprise integrating research and development, production, installation and after-sales service of exhaust gas treatment and dust control engineering equipment. Our products are suitable for environmental management in various industries such as furniture industry, wood products industry, shoemaking industry, chemical industry, feed mill, and electronics industry. We can design environment-friendly solutions to customer satisfaction according to different needs of customers.