CN206535421U - A kind of waste incinerator two-part flue gas purification system - Google Patents

Abstract

In order to solve the problems that the existing waste incinerator flue gas treatment system needs to install a heat exchanger at the tail to increase the flue gas temperature, resulting in heat loss and increasing energy consumption, the utility model proposes a two-stage flue gas treatment system for waste incinerators. The purification system is characterized in that, according to the direction of flue gas flow, it consists of sodium bicarbonate dry deacidification system, sodium bicarbonate injection system, first-stage bag filter, selective catalytic reduction device SCR, lime slurry preparation system, semi- It is composed of dry reaction tower (rotary atomizer), activated carbon storage and delivery system, activated carbon storage injection system and secondary bag filter. Since the selective catalytic reduction device SCR is installed after the first-stage bag filter and before the lime slurry preparation system and the semi-dry reaction tower, since the temperature of the flue gas has not decreased, the inlet temperature condition of the selective catalytic reduction device SCR is fully met. Therefore, there is no need to install a heat exchanger in front of the SCR, thereby reducing energy loss.

Description

A two-stage flue gas purification system for a waste incinerator

technical field

The utility model relates to a flue gas purification device of a garbage incinerator, in particular to a two-stage flue gas purification system of a garbage incinerator.

Background technique

At present, the waste incineration power plant incinerator flue gas treatment system uses the selective non-catalytic reduction method in the furnace to remove nitrogen oxides (NOx) in the flue gas, and then removes the nitrogen oxides (NOx) in the flue gas by semi-dry method and activated carbon injection plus bag filter. Other harmful substances such as particulate matter, sulfur oxides (SOx), dioxins, and heavy metals.

However, with the increasingly stringent laws and regulations related to environmental protection, the existing waste incineration power plant flue gas treatment system can no longer meet the requirements of laws and regulations, and it is necessary to install a selective catalytic reduction device on the flue gas pipe outside the furnace ( SCR), further denitrification of the flue gas can better meet the emission standards. Due to the existing SCR characteristics, the temperature of the influent flue gas is required to be around 200°C, and the flue gas cannot contain a large amount of sulfur and heavy metals, otherwise it will cause catalyst poisoning. In order to avoid the influence of harmful components in the flue gas on the SCR, in the prior art, the SCR is installed at the tail of the flue gas purification system.

The problem is that since the working temperature of the SCR is about 200°C, and the temperature of the flue gas flowing out from the tail of the flue gas purification system is mostly about 150°C, it is necessary to arrange one-stage or even multi-stage replacement between the original flue gas post-treatment system and the SCR. The heater heats the flue gas so that the original 150°C flue gas rises to 200°C before flowing into the SCR to meet the requirements of the SCR, but this will inevitably cause a large amount of heat loss and increase operating costs.

Utility model content

In order to solve the problems of the existing waste incinerator flue gas treatment system, in order to increase the flue gas temperature, a heat exchanger needs to be installed at the tail, resulting in heat loss and increasing energy consumption. , Dust removal system, rearrange the SCR and the original flue gas treatment system, set the selective catalytic reduction device SCR after the first-stage bag filter and before the lime slurry preparation system and the semi-dry reaction tower, so that the flow through the selective catalytic reduction The flue gas temperature of the SCR meets the requirements and meets the SCR working conditions, so there is no need to install a heat exchanger to save energy.

The technical scheme adopted by the utility model to solve the technical problem is: a two-stage flue gas purification system for a garbage incinerator, which is characterized in that, according to the direction of flue gas flow, the sodium bicarbonate dry deacidification system, carbonic acid Hydrogen and sodium injection system, primary bag filter, selective catalytic reduction device SCR, lime slurry preparation system, semi-dry reaction tower (rotary atomizer), activated carbon storage and delivery system, activated carbon storage injection system and secondary bag filter composition. When the flue gas with a temperature of 200°C flows out of the economizer, it flows through the sodium bicarbonate injection system, and the sodium bicarbonate sprayed by the sodium bicarbonate nozzle is fully mixed with the flue gas. Most of the acid gases (mainly SOx), particulate matter and other solid substances in the flue gas are captured by the bag. Since the flue gas travel is short and there is no other heat loss during this process, the flue gas flows out of the first-stage bag filter. The temperature is still about 200°C, which fully meets the SCR inlet temperature conditions, and since most of the particulate matter and acid gas in the flue gas have been removed, the working conditions of the SCR are already met, and the flue gas undergoes selective catalytic reduction in the SCR. Further remove NOx in the flue gas. After flowing out from the SCR, it enters the conventional semi-dry reaction tower (rotary sprayer), the lime slurry is fully mixed with the flue gas, and then passes through the activated carbon injection system and then flows through the secondary bag filter to remove SOx, particulate matter, and dioxins in the flue gas. , heavy metals and other harmful substances for further removal.

Beneficial effects of the utility model: the utility model provides a two-stage flue gas purification system of a garbage incinerator. Since the selective catalytic reduction device SCR is arranged after the first-stage bag filter, the lime slurry preparation system and the semi-dry reaction Before the tower, because the temperature of the flue gas has not decreased, it fully meets the SCR inlet temperature condition of the selective catalytic reduction device. Therefore, the technical solution proposed by the utility model does not need to install a heat exchanger at the front end of the SCR, thereby reducing energy loss and at the same time , Since the lime slurry preparation system and the semi-dry reaction tower are equipped with a secondary bag filter, the purification efficiency of the flue gas can be further improved to achieve the purpose of energy saving and high efficiency.

Description of drawings

Fig. 1 is a device layout diagram of an embodiment of the prior art.

Fig. 2 is an equipment layout diagram of an embodiment of a waste incinerator two-stage flue gas purification system installed in the waste incinerator flue gas pipeline proposed by the utility model.

In the picture:

1. Sodium bicarbonate preparation system,

2. Sodium bicarbonate injection system,

3.1 first-level bag dust removal, 3.2 second-level bag dust removal,

4. Selective Catalytic Reduction (SCR),

5. Lime preparation system,

6. Conventional semi-dry reaction tower (rotary atomizer),

7. Activated carbon storage and delivery system,

8. Activated carbon injection system,

9. Heat exchanger,

10.1 Flue gas duct

10.21 The direction of flue gas inflow, 10.22 The direction of flue gas flow out.

detailed description

Fig. 1 is a device layout diagram of an embodiment of the prior art. The figure shows that in the prior art, the flue gas purification system installed in the flue gas pipeline of the waste incinerator is sequentially composed of a lime slurry preparation system 5 and a semi-dry reaction tower (rotary atomizer) according to the direction of flue gas flow. 6. Activated carbon storage and delivery system 7. Activated carbon injection system 8. First-stage bag filter 3.1. Heat exchanger 9. Selective catalytic reduction device (SCR) 4. As shown in the figure, the waste incinerator flue gas purification system needs to install a heat exchanger 9 at the front end of the selective catalytic reduction (SCR) 4. The reason is that since the working temperature of the SCR is about 200°C, After flowing in from the flue gas pipe 10.1 according to the flue gas inflow direction 10.21, it enters the semi-dry reaction tower 6 and passes through the lime slurry rotary sprayer. The lime slurry is fully mixed with the flue gas, and then passes through the activated carbon injection system 8, and then flows through the first stage bag dust removal. Device 3.1 further removes SOx, particles, dioxins, heavy metals and other harmful substances in the flue gas. At this time, the temperature of the flue gas has been greatly reduced. Usually, the temperature can only reach 140 ° C, which cannot meet the SCR inlet working temperature. Therefore, a heat exchanger 9 must be installed at the front end of the selective catalytic reduction (SCR) 4. But this will inevitably lead to heat loss and increase energy consumption.

Fig. 2 is an equipment layout diagram of an embodiment of a waste incinerator two-stage flue gas purification system installed in the waste incinerator flue gas pipeline proposed by the utility model. The figure shows that in this example, a two-stage flue gas purification system for a waste incinerator is characterized in that, according to the direction of flue gas flow, the sodium bicarbonate dry deacidification system 1 and the sodium bicarbonate injection system 2 are sequentially , first-stage bag filter 3.1, selective catalytic reduction (SCR) 4, lime slurry preparation system 5, semi-dry reaction tower (rotary atomizer) 6, activated carbon storage and delivery system 7, activated carbon storage injection system 8 and two The composition of stage bag filter 3.2. When the flue gas with a temperature of 200 °C flows out of the economizer, it flows through the sodium bicarbonate injection system 2. The small crystals of sodium bicarbonate sprayed out by the sodium bicarbonate nozzle are fully mixed with the flue gas. When the flue gas flows through the first-stage bag filter Most of the acid gases (mainly SOx), particulate matter and other solid substances in the flue gas in the filter 3.1 are captured by the first-stage bag filter. Since the flue gas travel is short and there is no other heat loss in this process, the first-stage bag filter 3.1 After the flue gas flows out, the temperature is still about 200°C, which fully meets the SCR inlet temperature conditions. At the same time, since most of the particles and acid gases in the flue gas have been removed, the working conditions of the SCR are already met, and the flue gas is selective in the SCR. Catalytic reduction reaction to further remove NOx in flue gas. After flowing out from the selective catalytic reduction device (SCR) 4, it enters the conventional semi-dry reaction tower (rotary atomizer) 6, the lime slurry is fully mixed with the flue gas, and then flows through the activated carbon injection system 8 and then flows through the secondary bag filter 3.2 pairs SOx, particles, dioxins, heavy metals and other harmful substances in the flue gas are further removed. In this example, since the selective catalytic reduction device SCR is installed after the first-stage bag filter and before the lime slurry preparation system and the semi-dry reaction tower, the temperature of the flue gas does not decrease, which fully meets the requirement of selective catalytic reduction. Therefore, the technical solution proposed by the utility model does not need to install a heat exchanger at the front end of the SCR, thereby reducing energy loss. At the same time, since a secondary bag filter is installed after the semi-dry reaction tower, it can be used Further improve the purification efficiency of flue gas to achieve the purpose of energy saving and high efficiency. The difference between this example and the prior art is that the prior art is to arrange the selective catalytic reduction device (SCR) 4 after the semi-dry reaction tower (rotary atomizer) 6, the activated carbon storage injection system 8 and the bag filter; And the scheme that the utility model proposes is that the selective catalytic reduction device (SCR) 4 is arranged before the semi-dry reaction tower (rotary atomizer) 6, the activated carbon storage injection system 8 and the bag filter, the biggest difference this time; In addition, in the utility model, in order to ensure that the flue gas meets the inlet conditions before the selective catalytic reduction device (SCR) 4, the flue gas is also made to flow through the sodium bicarbonate injection system 2 and the sodium bicarbonate injection system before the selective catalytic reduction device (SCR) 4 The previous stage of the bag filter.

In this utility model, due to sodium bicarbonate dry deacidification system 1, sodium bicarbonate injection system 2, first-stage bag filter 3.1, selective catalytic reduction (SCR) 4, lime slurry preparation system 5, semi-dry Reaction tower (rotary atomizer) 6, activated carbon storage and delivery system 7, activated carbon storage injection system 8, heat exchanger 9, etc. are all conventional equipment in the industry, so no further detailed description is required.

Claims (1)

1. a kind of waste incinerator two-part flue gas purification system, it is characterized in that, according to the direction of flow of flue gas, successively by carbonic acid Hydrogen sodium dry-process deacidification system, sodium acid carbonate spraying system, one-level sack cleaner, SCR device SCR, lime white system Standby system, half dry type reaction tower, activated carbon storing/conveying system, activated carbon storage spraying system and two grades of sack cleaner groups Into.