CN101275746A - New Waste Incineration Flue Gas Purification System and Purification Process - Google Patents

Abstract

The invention belongs to the waste gas handling technical field, particularly a novel waste burning gas cleaning system and the cleaning technology, wherein the system includes a dump dry type gas washing tower, a circulating fluid bed, a bag dust collector and a fan, and the cleaning technology is: the gas enters the dump dry type gas washing tower through the gas entry, which removes the sour gas in the gas; the cleaned gas enters the circulating fluid bed through the tower gas outlet, which removes the water and the residue sour gas, and enters the bag dust collector through the gas outlet of the circulating fluid bed; the bag dust collector filters the fine dust particles, the neutralizer particles, the deacidification reaction product particles and the active carbon particles in the gas, the cleaned gas is discharged into the air through the fan and the chimney. The system and the technology of the invention can greatly advance the cleaning capacity to the gas with wide accommodation limit and regulating range, low cost.

Description

New Waste Incineration Flue Gas Purification System and Purification Process

technical field

The invention belongs to the technical field of waste gas treatment, and in particular relates to a novel waste incineration flue gas purification system and purification process.

Background technique

At present, wastes containing more combustible components are usually reduced and harmlessly treated by incineration. Conventional incineration systems often produce new pollutants, such as acid gases (SO ₂ , NO, etc.), dioxins, etc. wait. These pollutants will damage the atmospheric environment and cause harm to the human body, so the flue gas after incineration must be purified. The flue gas purification system used in the national patent "incineration treatment system for hazardous waste in industrial areas" (patent number: 02235414.X) is composed of a water scrubber tower and a bag filter. Patent No.: 200420050509.9) The flue gas purification system used is composed of a spray tower, a bag filter and a secondary bag filter. Although these flue gas purification systems can effectively remove pollutants such as acid gases, the moisture in the flue gas It cannot be effectively removed, which will cause internal corrosion of the bag filter and shorten the service life. Furthermore, because there are many types of wastes incinerated, the output of pollutants generated fluctuates greatly, so only using scrubbers cannot guarantee the complete removal of pollutants. Spraying activated carbon or hydrated lime into pipelines or scrubbers can further adsorb pollutants and reduce their emissions, but due to insufficient contact, activated carbon or hydrated lime has poor adsorption effects on pollutants. Moreover, due to the immeasurable amount of pollutants, when the amount of pollutants is small, it will cause waste of activated carbon or slaked lime. The present invention aims at improving the purification and treatment capacity of the waste incineration flue gas and reducing the treatment cost in order to provide a novel waste incineration flue gas purification system for the above problems in the waste incineration flue gas purification system.

Contents of the invention

The present invention solves the problems existing in the prior art, and in particular relates to a novel waste incineration flue gas purification system and purification process.

Technical scheme of the present invention is as follows:

A new waste incineration flue gas purification system, the system consists of a semi-dry scrubber 1, a circulating fluidized bed 4, a bag filter 7 and a fan 10;

The top of the semi-dry scrubber 1 is provided with a flue gas inlet 2, and an atomizer is installed inside;

The bottom of the circulating fluidized bed 4 is provided with a fluidized bed inlet 5, which communicates with the gas outlet 3 of the scrubber; the bottom of the circulating fluidized bed 4 is provided with a discharge mechanism.

The dust collector inlet 8 of the bag filter 7 is connected to the fluidized bed outlet 6 , the dust collector outlet 9 is connected to a fan 10 , and the fan 10 is connected to a chimney 11 .

A new waste incineration flue gas purification process, the flue gas purification includes the following steps:

Step 1. The flue gas enters the semi-dry scrubber 1 through the flue gas inlet 2, and the slaked lime slurry or water is sprayed from the top or bottom of the semi-dry scrubber 1 through the high-efficiency atomizer to form a codirectional flow Or the way of countercurrent flow fully interacts with the flue gas to remove the acid gas in the flue gas; the temperature of the flue gas passing through the gas scrubber outlet 3 is below 200°C to prevent the formation of dioxins.

Step 2, the purified flue gas enters the circulating fluidized bed 4 through the gas outlet 3 of the scrubber, removes the moisture and residual acid gas in the flue gas, and enters the bag filter 7 through the gas outlet 6 of the fluidized bed; The bed material in the fluidized bed 4 is a mixture of CaCO ₃ or CaO powder and activated carbon powder, wherein the molar ratio of CaCO ₃ or CaO powder to activated carbon powder is between 1000:1 and 10:1. The temperature of the flue gas passing through the gas outlet 6 of the fluidized bed is 120-180°C.

Step 3: After the bag filter 7 filters the fine dust particles, neutralizer particles, deacidification reaction product particles and activated carbon particles in the flue gas, the flue gas is discharged from the air outlet 9 of the dust collector; The temperature is 80-120°C.

Step 4, the purified flue gas is discharged into the atmosphere through the chimney 11 of the fan 10 .

When the amount of waste incineration is small, the semi-dry scrubber can only spray water to cool down, and the circulating fluidized bed and bag filter can undertake the task of flue gas purification; when the amount of waste incineration is large, the three can be used in combination .

The beneficial effect of the present invention is that the combined use of the semi-dry gas scrubber and the circulating fluidized bed can greatly improve the system’s ability to purify the flue gas, and has a wide range of adaptation, a large adjustment range, and reduced operating costs; the circulating fluidized bed and the bag filter The combined use can achieve two dust removals to ensure the thorough purification of the flue gas. And the flue gas purified by the system and process of the present invention complies with the emission standards stipulated in the national standard "Pollution Control Standards for Hazardous Waste Incineration" GB18484-2001 and "Standards for Pollution Control of Domestic Garbage Incineration" GB18485-2001.

Description of drawings

Fig. 1 is a schematic diagram of the system of the present invention

Among them, 1 is a semi-dry scrubber, 2 is the flue gas inlet, 3 is the outlet of the scrubber, 4 is the circulating fluidized bed, 5 is the inlet of the fluidized bed, 6 is the outlet of the fluidized bed, and 7 is the For the bag filter, 8 is the air inlet of the dust collector, 9 is the air outlet of the dust collector, 10 is the fan, and 11 is the chimney.

Fig. 2 is a process flow diagram of the present invention

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

Referring to Figure 1, the system is mainly composed of a semi-dry scrubber 1, a circulating fluidized bed 4, a bag filter 7 and a fan 10.

Referring to Figure 1 and Figure 2, the flue gas enters from the flue gas inlet 2 at the top of the semi-dry scrubber 1, and the slaked lime slurry is sprayed into the semi-dry scrubber 1 from the bottom of the tower upwards or downwards from the top of the tower, and is simultaneously The internal high-efficiency atomizer atomizes, makes it fully contact with the high-temperature flue gas and produces a neutralizing effect, removes the acid gas in the flue gas, and rapidly cools the flue gas. The flue gas temperature can be lowered below 200°C to prevent the regeneration of dioxins.

The flue gas enters the circulating fluidized bed 4 after coming out of the semi-dry scrubber 1, and the bottom is provided with an air inlet 5, which communicates with the gas outlet 3 of the semi-dry scrubber 1, and the bottom of the circulating fluidized bed 4 is provided with There is a discharge mechanism, and the bed material is a mixture of CaCO ₃ or CaO powder and activated carbon powder. When the semi-dry scrubber 1 sprays slaked lime slurry, the molar ratio of CaCO _or CaO powder to activated carbon powder is between 1000:1 and 10:1; When the waste is high, the content of activated carbon in the bed material is increased, and the molar ratio to CaCO ₃ or CaO powder can be controlled at about 100:1 to 10:1. When the semi-dry scrubber only sprays water to cool down, the molar ratio of CaCO ₃ or CaO powder to activated carbon powder is between 1000:1 and 10:1. The circulating fluidized bed 4 plays the role of adjusting humidity and removing pollutants such as residual acid gas, so that the flue gas can be purified in the second step, and it also protects the bag filter 7: due to the complex types of waste, the generated pollutants The output is not constant, and the flue gas contains moisture and acid gas after coming out of the semi-dry scrubber, which will affect the working condition and service life of the bag filter 7. The bed material of the circulating fluidized bed 4 can absorb moisture, thereby reducing or even The moisture in the flue gas is removed, and the humidity of the flue gas is adjusted. At the same time, the alkaline bed material CaCO or CaO powder in the circulating fluidized bed ₄ removes the unremoved acid gas in the semi-dry scrubber 1 again, thereby The working condition of the bag filter 7 is improved and the service life is extended; the bed material mixed with activated carbon powder can also adsorb dioxins and heavy metals; the circulating fluidized bed 7 can rely on its own unique advantages to make the bed The material is in full contact with the flue gas, and the adsorption effect of the bed material on pollutants can be improved. At the same time, the bed material can be recycled to improve its utilization and avoid the waste of CaCO ₃ or CaO and activated carbon.

The flue gas enters the bag filter 7 after coming out of the circulating fluidized bed 4 . The air outlet 6 of the circulating fluidized bed is connected to the air inlet 8 of the bag filter. As the last process of the purification system, the bag filter collects fine dust particles, neutralizers, deacidification reaction product particles and activated carbon particles in the flue gas through filtration and then discharges them. The flue gas is discharged from the outlet 9 of the bag filter to realize the third step of flue gas purification. Finally, the purified flue gas is discharged into the atmosphere through the fan 10 and the chimney 11.

The purification system and purification process of the present invention can greatly improve the system's ability to purify flue gas, have a wide range of adaptation, a large adjustment range, and reduce operating costs.

Claims (4)

1. A new waste incineration flue gas purification system, characterized in that: The system consists of a semi-dry scrubber (1), a circulating fluidized bed (4), a bag filter (7) and a fan (10); The top of the semi-dry gas scrubber (1) is provided with a flue gas inlet (2), and an atomizer is installed inside; The bottom of the circulating fluidized bed (4) is provided with a fluidized bed inlet (5), which communicates with the gas scrubber outlet (3); The dust collector inlet (8) of the bag filter (7) is connected to the fluidized bed outlet (6), and the dust collector outlet (9) is connected to the fan (10), and the fan (10) is connected to the chimney (11) connected. 2. A new waste incineration flue gas purification process, characterized in that it comprises the following steps: Step 1. The flue gas enters the semi-dry scrubber (1) through the flue gas inlet (2), and the slaked lime slurry or water is sprayed from the top or bottom of the semi-dry scrubber (1) through the high-efficiency atomizer Inlet, the way of forming cocurrent or countercurrent flow fully interacts with the flue gas to remove the acid gas in the flue gas; Step 2. The purified flue gas enters the circulating fluidized bed (4) through the gas scrubber outlet (3), removes the moisture and residual acid gas in the flue gas, and enters the bag dust removal through the fluidized bed gas outlet (6) device (7); Step 3: After the bag filter (7) filters out the fine dust particles, neutralizer particles, deacidification reaction product particles and activated carbon particles in the flue gas, the flue gas is discharged from the dust collector outlet (9); Step 4, the purified flue gas is discharged into the atmosphere through the blower fan (10) and the chimney (11). 3. A new waste incineration flue gas purification process according to claim 2, characterized in that: the bed material of the circulating fluidized bed in the second step is CaCO ₃ or a mixture of CaO powder and activated carbon powder, wherein CaCO ₃ or the molar ratio of CaO powder to activated carbon powder is between 1000:1 and 10:1. 4. A new waste incineration flue gas purification process according to claim 2, characterized in that: the temperature of the flue gas passing through the gas scrubber outlet (3) is below 200°C, and passing through the fluidized bed gas outlet (6 ) is 120 to 180°C, and the temperature at the air outlet (9) of the dust collector is 80 to 120°C.

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