CN105698550B - The sintering smoke purifying system and method for a kind of energy-saving and emission-reduction - Google Patents

Abstract

The object of the present invention is to solve the problems existing in the existing sintering flue gas purification technology, and provide a sintering flue gas purification system and method for energy saving and emission reduction, belonging to the technical field of sintering flue gas purification. The system includes sintering machine, flue gas distributor, sintering machine bottom air box, sintering machine large flue, electric dust collector, sintering main exhaust fan, 1# fan, 2# fan, adsorption tower, chimney, material conveying equipment and regeneration tower ; Moreover, the system is equipped with a heat exchanger in the large flue of the sintering machine, or the system is also equipped with a dust collector, and the devices are connected in sequence through pipelines. The method includes heat utilization of flue gas of sintering machine, adsorption of adsorption tower and regeneration of active coke. The system and method reduce investment and operating costs on the basis of effectively controlling flue gas temperature, making full use of hot waste gas, reducing the scale of activated coke flue gas purification devices, avoiding secondary pollution, and realizing resource recycling.

Description

A sintering flue gas purification system and method for energy saving and emission reduction

technical field

The invention belongs to the technical field of sintering flue gas purification, and in particular relates to an energy-saving and emission-reducing sintering flue gas purification system and method.

Background technique

A large amount of flue gas is produced during the sintering production process, and substances such as SOx, NOx, particulate matter, heavy metals and dioxins contained in the flue gas pollute the environment. With the increasingly stringent national environmental protection requirements, the technology of comprehensive treatment of multiple pollutants is an inevitable trend in the development of flue gas treatment. The activated coke flue gas purification process can realize low-temperature denitrification on the basis of desulfurization, and has a certain removal effect on dust, heavy metals, dioxins and other pollutants. In addition, the by-product of desulfurization is high-quality sulfuric acid, which can recover sulfur resources, conforms to the concept of circular economy, and is currently recognized as the most promising comprehensive treatment technology for various pollutants in the world. However, when the activated coke flue gas purification process is applied to sintering flue gas treatment, there are still the following problems:

(1) Sintering flue gas temperature control

The temperature of the sintering flue gas fluctuates greatly, and the temperature is 120-180°C during normal operation; while the activated coke flue gas purification process requires the inlet flue gas temperature not to exceed 150°C, if the inlet flue gas temperature is higher than 150°C, it is easy to cause the active coke bed layer overheating phenomenon, affecting the normal operation of the system. Chinese patent ZL2013102748101 discloses a method for cooling flue gas: cooling the flue gas by mixing cold air into the system and spraying cooling water. However, adding cold air will increase the load of downstream fans and adsorption towers, increasing system energy consumption and investment; increasing the amount of flue gas will reduce the contact time between flue gas and activated coke bed, affecting the purification effect; spraying cooling water to cool down will cause corrosion To solve the problem of corrosion resistance, the downstream flue gas pipelines, fans, adsorption towers and other facilities need to improve the anti-corrosion level. At the same time, the increase of water content in the flue gas will reduce the removal effect of nitrogen oxides.

(2) Exhaust of hot flue gas during active coke regeneration

As shown in Figure 1, in the prior art, a regeneration tower similar to a shell-and-tube heat exchanger is used to regenerate active coke. °C, then cooled to 80-120 °C through the cooling section, and finally reached the bottom of the regeneration tower 404. In the heating section: the high-temperature hot air at 400-470°C is exchanged and the temperature becomes 300-350°C and discharged by the fan 401, part of the hot air is returned to the gas burner 402 for recycling, and the other part is discharged outside; in the cooling section: normal temperature air is passed through The fan 403 enters the regeneration tower 404 for heat exchange and discharges outside, and the cooling air temperature of the discharge outside is 80-120°C. In summary, both the heating section and the cooling section of the regeneration tower have the phenomenon of exhaustion of hot exhaust gas, resulting in energy waste. Chinese patent application CN201410427293 discloses a method for utilizing waste heat in the regeneration process of activated coke: part of the hot air is used for gas preheating and exhausted; part of the exhausted cooling air is used for combustion-supporting air for gas combustion, and the other part is directly discharged. However, this process method still has the phenomenon of exhaust gas containing heat, and the energy cannot be fully recovered.

(3) Large investment in activated coke flue gas purification process

Under the condition of the same flue gas volume, the initial investment of activated coke flue gas purification process is generally 2 to 3 times of the initial investment of wet and semi-dry desulfurization process, which also limits the popularization and application of activated coke flue gas purification process. Therefore, reducing the scale of activated coke flue gas purification equipment to reduce investment and operating costs is a problem that must be solved for the promotion and application of activated coke flue gas purification technology.

(4) Secondary pollution in activated coke flue gas purification process

There are secondary pollution problems in the flue gas purification process of activated coke _: for example, when the high SO2 concentration gas generated in the regeneration process of activated coke is used to produce concentrated sulfuric acid, waste gas will be generated, which contains SOx, sulfuric acid mist, etc.; There will be damage during the coke cycle, and the damaged activated coke will be sieved by a vibrating sieve to produce solid waste (coke powder).

In summary, the existing activated coke flue gas purification process has disadvantages such as unreasonable flue gas temperature control, hot exhaust gas discharge, energy waste, large initial investment, and secondary pollution. It is necessary to develop active coke suitable for sintering machine production The flue gas purification process and method, on the basis of effectively controlling the flue gas temperature, making full use of the heat-containing waste gas, reducing the scale of the activated coke flue gas purification device and avoiding secondary pollution, can reduce investment and operating costs.

Contents of the invention

The purpose of the present invention is to solve the problems existing in the prior art, and provide an energy-saving and emission-reducing sintering flue gas purification system and method. On the basis of large scale and avoiding secondary pollution, the investment and operating costs can be reduced.

A sintering flue gas purification system for energy saving and emission reduction, including sintering machine, flue gas distributor, bellows at the bottom of sintering machine, large flue duct of sintering machine, electrostatic precipitator, sintering main exhaust fan, 1# fan, 2# fan, adsorption towers, chimneys, material handling equipment and regeneration towers;

The system also has a heat exchanger in the large flue of the sintering machine, and the sintering machine, the bellows at the bottom of the sintering machine, the large flue of the sintering machine, the electrostatic precipitator, the sintering main exhaust fan, the 1# fan, the adsorption tower and the chimney are connected in sequence through pipes , and the outlet of the sintering main exhaust fan is connected to the inlet of the 2# fan through the circulating flue gas pipe drawn from the branch; wherein, in the above system, the flue gas distributor is located on the sintering machine trolley, and the outlet of the 2# fan is connected to the flue gas The gas distributor is connected through pipelines; the adsorption tower is provided with an air inlet and an air outlet, and both the adsorption tower and the regeneration tower are provided with a feed inlet and a discharge outlet, and the outlet of the adsorption tower is fed through the material conveying equipment and the regeneration tower The inlet of the adsorption tower is connected with the outlet of the regeneration tower through the material conveying equipment;

The regeneration tower is a regeneration tower in the prior art. The regeneration tower is provided with a heating section, an air extraction section and a cooling section from top to bottom. The cooling section finally reaches the discharge port at the bottom of the regeneration tower; the heating section is equipped with a high-temperature hot air inlet and outlet, and a 3# fan and a hot-blast stove are installed outside. The inlet of the 3# fan and the outlet of the 3# fan are connected to the inlet of the hot blast stove through pipes; the exhaust section of the regeneration tower is equipped with a gas outlet, and a contact method acid system is installed on the outside, and the gas outlet is connected to the gas inlet of the acid system through a pipeline; the regeneration tower The cooling section is equipped with a cooling air inlet and outlet, and a 4# fan is installed outside, and the outlet of the 4# fan is connected to the cooling air inlet;

Or, another energy-saving and emission-reducing sintering flue gas purification system, including sintering machine, flue gas distributor, sintering machine bottom bellows, sintering machine large flue, electric dust collector, sintering main exhaust fan, 1# fan, 2# fan, adsorption tower, chimney, material conveying equipment and regeneration tower;

The system is also equipped with a dust collector. The sintering machine is connected to the bottom bellows of the sintering machine through pipelines. The several bellows at the head and the tail several bellows in the bottom bellows of the sintering machine are connected to the dust collector through pipelines. The remaining bellows at the bottom of the sintering machine, The large flue of the sintering machine, the electrostatic precipitator, the sintering main exhaust fan, the 1# fan, the adsorption tower and the chimney are connected in sequence through pipes, and the dust collector is connected with the inlet of the 2# fan through pipes;

Wherein, in the above system, the flue gas distributor is located on the sintering machine trolley, and the outlet of the 2# fan is connected to the flue gas distributor through a pipeline; the adsorption tower is provided with an air inlet and an air outlet, and the adsorption tower and regeneration The towers are equipped with feed inlets and outlets, the outlet of the adsorption tower is connected to the inlet of the regeneration tower through material conveying equipment, and the inlet of the adsorption tower is connected to the outlet of the regeneration tower through material conveying equipment;

The regeneration tower is a regeneration tower in the prior art. The regeneration tower is provided with a heating section, an air extraction section and a cooling section from top to bottom. The cooling section finally reaches the discharge port at the bottom of the regeneration tower; the heating section is equipped with a high-temperature hot air inlet and outlet, and a 3# fan and a hot-blast stove are installed outside. The inlet of the 3# fan and the outlet of the 3# fan are connected to the inlet of the hot blast stove through pipes; the exhaust section of the regeneration tower is equipped with a gas outlet, and a contact method acid system is installed on the outside, and the gas outlet is connected to the gas inlet of the acid system through a pipeline; the regeneration tower The cooling section is equipped with a cooling air inlet and outlet, and a 4# fan is installed outside, and the outlet of the 4# fan is connected to the cooling air inlet;

Preferably, in the systems of the above two structures, the heating section of the regeneration tower and the cooling section of the regeneration tower are both in the form of shell and tube heat exchange;

When the hot blast stove is a gas-fired furnace, the surplus gas in the iron and steel plant can be fully utilized as fuel to save fuel costs as a whole;

Furthermore, in the systems of the above two structures, the outlet of the 3# fan is provided with a branch pipeline connected to the inlet of the 2# fan, and the cooling air outlet of the cooling section of the regeneration tower is connected to the inlet of the 2# fan through a pipeline;

Furthermore, in the systems of the above two structures, a vibrating screen is also provided at the bottom of the regeneration tower, and the vibrating screen is provided with a feed inlet, a large particle material outlet and a small particle material outlet; the discharge port of the regeneration tower is connected to the vibrating screen feed The large particle material outlet of the vibrating screen is connected to the inlet of the adsorption tower through the material conveying equipment, and the small particle material outlet of the vibrating screen is connected to the sintering machine batching system outside the system;

Even better, in the systems of the above two structures, the contact method acid system is provided with an air outlet, and the air outlet is connected to the inlet of the 1# fan through a pipeline;

Optimally, in the systems of the above two structures, a stepless regulating valve is set on the circulating flue gas pipeline; the pipeline between the outlet point of the circulating flue gas pipeline and the gas outlet of the contact acid system and the connection point of the 1# fan inlet pipeline Set a stepless regulating valve on the top; set a stepless regulating valve on the pipeline connected to the inlet and outlet of the adsorption tower; set a stepless regulating valve and a throttling valve on the pipeline connecting the outlet of the 3# fan and the inlet of the 2# fan; Set a stepless regulating valve and a throttling valve on the pipeline connecting the cooling air outlet of the cooling section of the tower to the inlet of the 2# fan; set a stepless regulating valve on the pipeline connecting the outlet of the contact acid system to the inlet of the 1# fan; #The air branch pipeline connected with the air is set at the inlet of the fan, and a stepless regulating valve and a throttle valve are set on the pipeline.

An energy-saving and emission-reducing sintering flue gas purification method utilizes the energy-saving and emission-reducing sintering flue gas purification system of the above two structures, including the following steps:

1) Heat utilization of sintering machine flue gas

Use method a or b as follows:

Method a: The high-temperature flue gas generated by the sintering of the sintering machine enters the large sintering flue through the bellows at the bottom of the sintering machine. The gas enters the adsorption tower after being pressurized by the 1# fan, and the rest of the flue gas enters the pipe at the front end of the 2# fan as the circulating flue gas through the circulating flue gas pipeline;

Method b: The low-temperature flue gas from the bellows at the head part of the sintering machine and the high-temperature flue gas from the bellows at the tail of the sintering machine are passed into the pipeline and mixed as circulating flue gas, and the dust is removed by the dust collector and enters the pipeline at the front end of the 2# fan. The flue gas enters the large sintering flue, and after being dedusted by the electrostatic precipitator, pressurized by the sintering main exhaust fan and 1# fan, it enters the adsorption tower;

2) adsorption tower adsorption

The sintering flue gas transported to the adsorption tower is in contact with the active coke inside the adsorption tower, SO ₂ , NOx, particulate matter, dioxin and other pollutants in the flue gas are adsorbed by the active coke, and the purified flue gas is discharged through the chimney ;

3) Active coke regeneration

The activated coke that has adsorbed pollutants is transferred from the adsorption tower to the regeneration tower, and the activated coke enters from the top of the regeneration tower, is regenerated after being treated in the heating section, pumping section and cooling section, and finally reaches the bottom of the regeneration tower;

In the heating section: the high-temperature hot air heated to 400~470℃ by the hot blast stove enters from the side of the heating section of the regeneration tower, and conducts non-contact heat exchange with the active coke flowing through the heating section to heat the active coke, and the temperature of the high-temperature hot air becomes 300~ 350°C, and then output from the other side of the heating section; part of the high-temperature hot air after heat exchange is used as the external hot air, pressurized by the 3# fan, and then enters the pipeline at the front end of the 2# fan, and the other part returns to the hot blast stove and is heated again as a high temperature Hot air use;

When the hot blast stove is a gas burner, the surplus gas of the steel plant can be used as the fuel source, which saves the fuel cost as a whole;

In the gas extraction section: the high SO ₂ concentration gas produced during the regeneration of the active coke in the heating section is discharged from the exhaust section into the contact acid system to produce 98% sulfuric acid, and the tail gas produced by the acid system passes through the 1# fan After pressurized, it enters the adsorption tower, and the pollutants contained in the tail gas are adsorbed and removed by the active coke in the adsorption tower, and the purified tail gas is discharged from the chimney;

In the cooling section: the normal temperature air used as cooling air enters from the side of the cooling section of the regeneration tower after being pressurized by the 4# fan, and conducts non-contact heat exchange with the active coke flowing through the cooling section. After cooling the active coke, the cooling air heats up To 80 ~ 120 ℃, the external discharge enters the pipe at the front end of the 2# fan;

The regenerated active coke is discharged from the regeneration tower into the vibrating screen, and the activated coke particles with a particle size ≥ 1.5mm after screening are returned to the adsorption tower to continue working. raw material reuse;

The circulating flue gas generated in the above step 1), the outer hot air generated in the heating section and the outer cooling air generated in the cooling section in step 3) are mixed in the pipe at the front end of the 2# fan inlet to form a mixed flue gas, and then enter the 2 #The fan is pressurized, then passes through the flue gas distributor, and finally returns to the material surface of the sintering machine to participate in the sintering process, and the oxygen content in the mixed flue gas before entering the flue gas distributor should be controlled. If the oxygen content is insufficient, the air branch pipe should be opened Throttle valve and stepless regulating valve on the top, adjust the oxygen content by inhaling air;

Preferably, in step 1) method a of the above-mentioned sintering flue gas purification method, the heat exchange rate is adjusted by adjusting the water flow rate in the heat exchanger, so as to ensure that the temperature of the flue gas entering the adsorption tower is 120-140°C; The flue gas volume of the adsorption tower accounts for 50% to 80% of the total sintering flue gas volume, and the circulating flue gas volume entering the front end of the 2# fan inlet accounts for 20% to 50% of the total sintering flue gas volume, thereby effectively reducing the scale of the adsorption tower. Reduce investment and operating costs;

The steam or hot water generated after heat exchange by the heat exchanger can be used as a heat source, for example, the steam can be integrated into the steam pipe network of the factory area or enter the steam turbine unit to generate electricity;

In step 1) method b of the above-mentioned sintering flue gas purification method, by adjusting the number of low-temperature wind boxes at the head and high-temperature wind boxes at the tail, to ensure that the temperature of the flue gas entering the adsorption tower is 120-140°C; at the same time, the temperature of the flue gas entering the adsorption tower is controlled The amount of circulating flue gas that enters the front end of the 2# fan inlet accounts for 20% to 50% of the total sintering flue gas volume, thereby effectively reducing the electrostatic precipitator, sintering main exhaust fan and Adsorption tower scale, thereby reducing investment and operating costs;

In step 3) of the above sintering flue gas purification method, the temperature of the high-temperature hot air entering the heating section of the regeneration tower is 400-470°C, and the temperature drops to 300-350°C after heat exchange; the temperature of the cooling air discharged from the cooling section is 80-120°C ;The higher temperature exhausted hot air and outer cooling air are finally returned to the material surface of the sintering machine, thus avoiding the direct discharge of hot waste gas and completely recycling the energy; at the same time, the tail gas produced by the acid system is treated by the adsorption tower before being discharged , to avoid polluting the environment;

In step 3) of the above sintering flue gas purification method, before the mixed flue gas enters the flue gas distributor, the oxygen content should account for more than 15% of the volume of the mixed flue gas;

The above-mentioned sintering flue gas purification method can adjust the flow of gas in different pipelines through stepless regulating valves and throttle valves installed on the pipelines to ensure the pressure balance in different pipelines; for example, the Stepless regulating valve, a stepless regulating valve on the pipeline between the outlet point of the circulating flue gas pipeline and the gas outlet of the contact method acid system and the connection point of the 1# fan inlet pipeline, connected to the inlet and outlet of the adsorption tower The stepless regulating valve on the pipeline, the stepless regulating valve and throttling valve on the pipeline connecting the 3# fan outlet and the 2# fan inlet, and the stepless regulating valve and throttling valve on the pipeline connecting the cooling air outlet of the cooling section of the regeneration tower and the 2# fan inlet The stepless regulating valve and throttle valve, the stepless regulating valve on the pipeline connecting the outlet of the contact acid system with the inlet of the 1# fan, and the stepless regulating valve and throttle valve on the air branch pipeline.

Compared with the prior art, the present invention has the advantages of:

1. On the basis of effectively controlling flue gas temperature, making full use of hot waste gas, reducing the scale of activated coke flue gas purification equipment and avoiding secondary pollution, the system can reduce investment and operating costs.

2. In this method, the sensible heat of the sintering flue gas can be used to produce steam or hot water after being absorbed by the heat exchanger, or the sensible heat of the sintering flue gas can be returned to the material surface of the sintering machine, reducing the consumption of sintering fuel; thus effectively controlling the exhaust gas At the same time, energy recycling is realized.

3. In this method, the exhausted hot air and cooled air generated in the active coke regeneration stage are finally returned to the material surface of the sintering machine, which avoids the exhaustion of hot waste gas and completely recycles energy.

4. In this method, the amount of flue gas entering the adsorption tower is 50% to 80% of the total flue gas amount, which can effectively reduce the scale of the adsorption tower, thereby reducing investment and operating costs.

5. In this method, the tail gas produced by the contact method acid production system is discharged after being treated by the adsorption tower to avoid environmental pollution; the coke powder produced during the regeneration of activated coke is returned to the sintering machine batching system for reuse as sintering raw materials; secondary pollution is avoided .

Description of drawings

Fig. 1, is the regeneration tower schematic diagram of prior art;

Fig. 2 is a schematic diagram of a sintering flue gas purification system according to Embodiment 1 of the present invention;

Fig. 3 is a schematic diagram of a sintering flue gas purification system according to Embodiment 2 of the present invention;

Among them, 1-sintering machine, 2-air box at the bottom of sintering machine, 3-big flue of sintering machine, 4-heat exchanger, 5-electric dust collector, 6-sintering main exhaust fan, 7-1# fan, 8-adsorption Tower, 9-chimney, 10-1# belt conveyor, 11-1# bucket elevator, 12-2# bucket elevator, 13-regeneration tower, 14-vibrating screen, 15-sintering machine batching system, 16- 2# belt conveyor, 17-3# fan, 18-gas burner, 19-contact acid system, 20-4# fan, 21-2# fan, 22-flue gas distributor, 23-dust collector, 24-The pipeline at the front end of the fan inlet of 2#, 1301-heating section of regeneration tower, 1302-pumping section of regeneration tower, 1303-cooling section of regeneration tower, V1～V8-stepless regulating valve 1～8, M1～M3-throttling Valves 1-3, L-circulating flue gas pipeline, 401-fan 1, 402-gas burner, 403-fan 2, 404-existing technology regeneration tower;

The direction indicated by the arrow is the flow direction of material or gas.

detailed description

Example 1

A sintering flue gas purification system for energy saving and emission reduction, as shown in Figure 2, including a sintering machine 1, a sintering machine bottom bellows 2, a sintering machine large flue 3, a heat exchanger 4, an electric dust collector 5, and a sintering main exhaust fan 6. 1# fan 7, adsorption tower 8, chimney 9, 1# belt conveyor 10, 1# bucket elevator 11, 2# bucket elevator 12, regeneration tower 13, vibrating screen 14, sintering machine batching system 15, 2# belt conveyor 16, 3# fan 17, gas burner 18, contact acid system 19, 4# fan 20, 2# fan 21, flue gas distributor 22;

Among them, the sintering machine 1 is connected to the bellows 2 at the bottom of the sintering machine, the bellows 2 at the bottom of the sintering machine is connected to the large flue 3 of the sintering machine, the large flue 3 of the sintering machine is connected to the sintering main exhaust fan 6, and the sintering main exhaust fan 6 is connected to the 1# fan 7 connection, the 1# fan 7 is connected with the adsorption tower 8, and the adsorption tower 8 is connected with the chimney 9, and the above connections are all connected by pipelines;

The flue gas distributor 22 is located on the sintering machine 1 trolley; the heat exchanger 4 is in the large flue 3 of the sintering machine; the front end of the circulating flue gas pipe L is connected to the outlet of the main exhaust fan 6 through a stepless regulating valve 6V6, and the end is connected to The pipe 24 at the front end of the 2# fan inlet; the outlet of the 2# fan 21 is connected to the flue gas distributor 22;

The regeneration tower 13 includes an upper regeneration tower heating section 1301, an intermediate regeneration tower air extraction section 1302 and a lower regeneration tower cooling section 1303. Both the regeneration tower heating section 1301 and the regeneration tower cooling section 1303 are in the form of shell and tube heat exchange, and the regeneration tower 13 The upper part is provided with a material inlet, and the lower part is provided with a material outlet;

The heating section 1301 of the regeneration tower is equipped with a high-temperature hot air inlet and outlet. The high-temperature hot air inlet is connected to the outlet of the gas burner 18 through a pipeline, and the high-temperature hot air outlet is connected to the inlet of the 3# fan 17 through a pipeline, and the outlet of the 3# fan 17 is connected to the inlet of the gas burner 18. It is connected through pipelines, while 3# fan 17 is connected with circulating flue gas pipeline L through pipelines through stepless regulating valve 4V4 and throttle valve 1M1;

The air extraction section 1302 of the regeneration tower is provided with an air outlet, which is connected to the air inlet of the contact acid system 19 through a pipeline, and the air outlet of the acid system 19 is connected to the front pipe of the 1# fan 7 through a pipeline through a stepless regulating valve 7V7 ;

The cooling section 1303 of the regeneration tower is provided with a cooling air inlet and outlet. The outlet of the 4# fan 20 is connected to the cooling air inlet through a pipeline, and the cooling air outlet is connected to the circulating flue gas pipeline L through a pipeline through a stepless regulating valve 5V5 and a throttle valve 2M2;

The vibrating screen 14 is provided with a feed inlet, a large particle material outlet and a small particle material outlet;

The adsorption tower 8 is provided with inlet and outlet ports and inlet and outlet ports;

1# belt conveyor 10, 2# belt conveyor 16, 1# bucket elevator 11, 2# bucket elevator 12 constitute the material conveying equipment;

The discharge port at the bottom of the regeneration tower 13 is connected to the feed port of the vibrating screen 14; the large particle material outlet at the bottom of the vibrating screen 14 is connected to the feed port at the top of the adsorption tower 8 through 2# bucket elevator 12 and 2# belt conveyor 16; The small particle material outlet at the bottom of the vibrating screen 14 is connected to the sintering machine batching system 15 outside the system; the bottom outlet of the adsorption tower 8 is connected to the top feed inlet of the regeneration tower 13 through 1# belt conveyor 10 and 1# bucket elevator 11 ;

The pipeline at the inlet end of the adsorption tower 8 is equipped with a stepless regulating valve 2V2, and the pipeline at the gas outlet end of the adsorption tower 8 is equipped with a stepless regulating valve 3V3;

Set a stepless regulating valve 1V1 on the pipeline between the outlet point of the circulating flue gas pipeline L and the connection point between the gas outlet of the acid system 19 and the inlet pipeline of the 1# fan;

An air branch pipe is set at the end of the circulating flue gas pipe L to communicate with the air, and a stepless regulating valve 8V8 and a throttle valve 3M3 are set on the air branch pipe.

Example 2

A sintering flue gas purification system for energy saving and emission reduction, as shown in Figure 3, including sintering machine 1, sintering machine bottom bellows 2, sintering machine large flue 3, electric dust collector 5, sintering main exhaust fan 6, and #1 fan 7. Adsorption tower 8, chimney 9, 1# belt conveyor 10, 1# bucket elevator 11, 2# bucket elevator 12, regeneration tower 13, vibrating screen 14, sintering machine batching system 15, 2# belt conveyor Machine 16, 3# fan 17, gas burner 18, contact acid system 19, 4# fan 20, 2# fan 21, flue gas distributor 22, dust collector 23;

Among them, the sintering machine 1 is connected to the bellows 2 at the bottom of the sintering machine, several bellows at the head and several bellows at the tail of the bellows 2 at the bottom of the sintering machine are connected to the dust collector 23, and the remaining bellows are connected to the large flue 3 of the sintering machine, and the large bellows of the sintering machine The flue 3 is connected to the electrostatic precipitator 5, the electrostatic precipitator 5 is connected to the sintering main exhaust fan 6, the sintering main exhaust fan 6 is connected to the 1# fan 7, the 1# fan 7 is connected to the adsorption tower 8, the adsorption tower 8 is connected to the chimney 9 Connection, the above connections are all connected by pipelines; the dust collector 23 is connected to the pipeline 24 at the front end of the inlet of the 2# fan through the pipeline; the outlet of the 2# fan 21 is connected to the flue gas distributor 22;

The regeneration tower 13 includes an upper regeneration tower heating section 1301, a middle regeneration tower air extraction section 1302 and a lower regeneration tower cooling section 1303. Both the regeneration tower heating section 1301 and the regeneration tower cooling section 1303 are in the form of shell and tube heat exchange, and the regeneration tower 13 The upper part is provided with a material inlet, and the lower part is provided with a material outlet;

The heating section 1301 of the regeneration tower is equipped with a high-temperature hot air inlet and outlet. The high-temperature hot air inlet is connected to the outlet of the gas burner 18 through a pipeline, and the high-temperature hot air outlet is connected to the inlet of the 3# fan 17 through a pipeline, and the outlet of the 3# fan 17 is connected to the inlet of the gas burner 18. It is connected through the pipeline, and the 3# fan is connected to the pipeline 24 at the front end of the inlet of the 2# fan through the pipeline through the stepless regulating valve 4V4 and the throttle valve 1M1;

The air extraction section 1302 of the regeneration tower is provided with an air outlet, which is connected to the air inlet of the contact acid system 19 through a pipeline, and the air outlet of the acid system 19 is connected to the front-end pipeline of the 1# fan 7 through a pipeline through a stepless regulating valve 7V7;

The cooling section 1303 of the regeneration tower is equipped with a cooling air inlet and outlet, the outlet of the 4# fan 20 is connected to the cooling air inlet through a pipeline, and the cooling air outlet passes through the pipeline through the stepless regulating valve 5V5 and the throttle valve 2M2 and the pipeline at the front end of the 2# fan inlet 24 connections;

The vibrating screen 14 is provided with a feed inlet, a large particle material outlet and a small particle material outlet;

The adsorption tower 8 is provided with inlet and outlet ports and inlet and outlet ports;

1# belt conveyor 10, 2# belt conveyor 16, 1# bucket elevator 11, 2# bucket elevator 12 constitute the material conveying equipment;

The discharge port at the bottom of the regeneration tower 13 is connected to the feed port of the vibrating screen 14; the large particle material outlet at the bottom of the vibrating screen 14 is connected to the feed port at the top of the adsorption tower 8 through 2# bucket elevator 12 and 2# belt conveyor 16; The small particle material outlet at the bottom of the vibrating screen 14 is connected to the sintering machine batching system 15 outside the system; the bottom outlet of the adsorption tower 8 is connected to the top feed inlet of the regeneration tower 13 through 1# belt conveyor 10 and 1# bucket elevator 11 ;

The pipeline at the inlet end of the adsorption tower 8 is equipped with a stepless regulating valve 2V2, and the pipeline at the gas outlet end of the adsorption tower 8 is equipped with a stepless regulating valve 3V3;

The pipe 24 at the front end of the 2# fan inlet is provided with an air branch pipe to communicate with the air, and a stepless regulating valve 8V8 and a throttle valve 3M3 are arranged on the air branch pipe.

Example 3

The method for purifying sintering flue gas using the energy-saving and emission-reducing sintering flue gas purification system of Embodiment 1 comprises the following steps:

1) Heat utilization of sintering machine flue gas

The high-temperature flue gas generated by the sintering of the sintering machine enters the large sintering flue through the bellows at the bottom of the sintering machine. The flue gas passes through the heat exchanger for heat exchange, and passes through the electric dust collector and the sintering main exhaust fan. Part of the flue gas is pressurized by the 1# fan and enters the adsorption The other part of the flue gas enters the pipe at the front end of the 2# fan from the circulating flue gas pipe as the circulating flue gas; by adjusting the flow of water in the heat exchanger, the heat exchange is adjusted to ensure that the temperature of the flue gas entering the tower is controlled at 120~ 140°C; after heat exchange by the heat exchanger, steam or hot water is generated as a heat source, and the steam can be incorporated into the steam pipe network of the plant or enter the steam turbine unit for power generation; at the same time, the flue gas returning to the material surface of the sintering machine is controlled to account for 20% of the total sintering flue gas 50%, the flue gas volume entering the adsorption tower is 50% to 80% of the total flue gas volume, thereby effectively reducing the scale of the adsorption tower, reducing investment and operating costs;

2) adsorption tower adsorption

The sintering flue gas transported to the adsorption tower is in contact with the active coke inside the adsorption tower, so that SO ₂ , NOx, particulate matter, dioxins and other pollutants in the flue gas are adsorbed by the active coke, and the purified flue gas passes through the chimney emission;

3) Active coke regeneration

The activated coke that has adsorbed pollutants is transferred from the bottom of the adsorption tower to the regeneration tower, and the activated coke enters from the top of the regeneration tower, and after being regenerated in the heating section, pumping section and cooling section, it finally reaches the bottom of the regeneration tower;

In the heating section: the high-temperature hot air heated to 400-470°C by the gas burner enters from one side of the heating section of the regeneration tower, conducts non-contact heat exchange with the active coke flowing through the heating section to heat the active coke, and then flows from the other side of the heating section Output from one side, the temperature of the high-temperature hot air after heat exchange becomes 300-350°C; part of the high-temperature hot air after heat exchange enters the pipe at the front end of the 2# fan, and the other part returns to the gas burner to be heated and used as high-temperature hot air;

Using a gas burner as a hot blast stove can use the surplus gas in the steel plant as a fuel source, saving fuel costs as a whole;

_In the gas extraction section: the high SO2 concentration gas produced during the regeneration of active coke is discharged from the exhaust section into the contact acid system to produce 98% sulfuric acid. The tail gas generated by the acid system enters the adsorption tower through the 1# fan, and Pollutants such as SOx and sulfuric acid mist are adsorbed and removed by the active coke in the adsorption tower;

In the cooling section: normal-temperature air as cooling air enters from one side of the cooling section of the regeneration tower, and conducts non-contact heat exchange with the active coke flowing through the cooling section. The cooling air discharged outside enters the pipe at the front end of the 2# fan;

When the mixed flue gas enters the flue gas distributor, the volume ratio of oxygen should be above 15%. If the oxygen concentration in the flue gas is insufficient, the throttle valve and stepless regulating valve on the air branch pipe should be opened to adjust the oxygen concentration by inhaling air. ;

The temperature of the high-temperature hot air entering the regeneration tower is 400-470°C, and the temperature drops to 300-350°C after heat exchange; the temperature of the external cooling air is 80-120°C; part of the high-temperature hot air and external cooling air after heat exchange are returned to the sintering machine material On the one hand, the exhaust of hot exhaust gas is avoided, and the energy is completely recycled; at the same time, the tail gas of the acid production system is discharged after being treated by the adsorption tower, so as to avoid polluting the environment;

The regenerated active coke is discharged from the bottom of the regeneration tower into the vibrating screen, and the activated coke particles with a particle size ≥ 1.5mm after sieving are returned to the adsorption tower to continue working. Sintering raw material recycling;

Due to the different gas sources and gas volumes in each pipeline, the flow of gas in different pipelines can be adjusted through stepless regulating valves and throttle valves installed on the pipelines to ensure the pressure balance in different pipelines; The stepless regulating valve on the pipeline, the stepless regulating valve on the pipeline between the lead-out point of the circulating flue gas pipeline and the gas outlet of the acid making system and the connection point of the 1# fan inlet pipeline, is connected with the inlet and outlet of the adsorption tower The stepless regulating valve on the connected pipeline, the stepless regulating valve and throttling valve on the pipeline connecting the outlet of the 3# fan with the inlet of the 2# fan, the outlet of the cooling air in the cooling section of the regeneration tower connected with the inlet of the 2# fan The stepless regulating valve and throttle valve on the pipeline, the stepless regulating valve on the pipeline connecting the outlet of the acid making system with the inlet of the 1# fan, and the stepless regulating valve and throttle valve on the air branch pipeline.

Example 4

The method for purifying sintering flue gas by utilizing the energy-saving and emission-reducing sintering flue gas purification system of Embodiment 2 comprises the following steps:

1) Heat utilization of sintering machine flue gas

The low-temperature flue gas from the bellows at the head part of the sintering machine and the high-temperature flue gas from the bellows at the tail of the sintering machine are passed into the pipeline and mixed as circulating flue gas. After dust removal by the dust collector, it enters the pipeline at the front end of the 2# fan, and the flue gas from the rest of the bellows enters the pipeline. The large sintering flue enters the adsorption tower after passing through the electrostatic precipitator, sintering main exhaust fan and 1# fan; by adjusting the number of low-temperature wind boxes at the head and high-temperature wind boxes at the tail, the temperature of the flue gas entering the adsorption tower is guaranteed to be 120-140°C; The final circulating flue gas accounts for 20% to 50% of the total sintering flue gas, and the flue gas volume entering the adsorption tower is 50% to 80% of the total flue gas volume, thereby effectively reducing the dust consumption of the electrostatic precipitator, sintering main exhaust fan and adsorption tower. scale, thereby reducing investment and operating costs;

2) adsorption tower adsorption

The sintering flue gas transported to the adsorption tower is in contact with the active coke inside the adsorption tower, so that SO ₂ , NOx, particulate matter, dioxins and other pollutants in the flue gas are adsorbed by the active coke, and the purified flue gas passes through the chimney emission;

3) Active coke regeneration

The activated coke that has adsorbed pollutants is transferred from the bottom of the adsorption tower to the regeneration tower, and the activated coke enters from the top of the regeneration tower, and after being regenerated in the heating section, pumping section and cooling section, it finally reaches the bottom of the regeneration tower;

In the heating section: the high-temperature hot air heated to 400-470°C by the gas burner enters from one side of the heating section of the regeneration tower, conducts non-contact heat exchange with the active coke flowing through the heating section to heat the active coke, and then flows from the other side of the heating section Output from one side, the temperature of the high-temperature hot air after heat exchange becomes 300-350°C; part of the high-temperature hot air after heat exchange enters the pipe at the front end of the 2# fan, and the other part returns to the gas burner to be heated and used as high-temperature hot air;

Using a gas burner as a hot blast stove can use the surplus gas in the steel plant as a fuel source, saving fuel costs as a whole;

_In the gas extraction section: the high SO2 concentration gas produced during the regeneration of active coke is discharged from the exhaust section into the contact acid system to produce 98% sulfuric acid. The tail gas generated by the acid system enters the adsorption tower through the 1# fan, and Pollutants such as SOx and sulfuric acid mist are adsorbed and removed by the active coke in the adsorption tower;

In the cooling section: normal-temperature air as cooling air enters from one side of the cooling section of the regeneration tower, and conducts non-contact heat exchange with the active coke flowing through the cooling section. The cooling air discharged outside enters the pipe at the front end of the 2# fan;

Before the mixed flue gas enters the flue gas distributor, the volume ratio of oxygen should be above 15%. If the oxygen concentration is insufficient, the throttle valve and stepless regulating valve on the air branch pipe should be opened to adjust the oxygen concentration by inhaling air; high temperature hot air The temperature entering the regeneration tower is 400-470°C, and the temperature drops to 300-350°C after heat exchange; the temperature of the cooling air outside is 80-120°C; part of the high-temperature hot air and cooling air after heat exchange return to the material surface of the sintering machine, It avoids the exhaust of hot waste gas, and the energy is completely recycled; at the same time, the tail gas of the acid production system is discharged after being treated by the adsorption tower, so as to avoid polluting the environment;

The regenerated active coke is discharged from the bottom of the regeneration tower into the vibrating screen, and the activated coke particles with a particle size ≥ 1.5mm after sieving are returned to the adsorption tower to continue working. Sintering raw material recycling;

Due to the different gas sources and gas volumes in each pipeline, the flow of gas in different pipelines can be adjusted through stepless regulating valves and throttle valves installed on the pipelines to ensure the pressure balance in different pipelines; The stepless regulating valve on the pipe connecting the air inlet and the air outlet, the stepless regulating valve and throttle valve on the pipe connecting the 3# fan outlet and the 2# fan inlet, the cooling air outlet and the cooling section of the regeneration tower cooling section The stepless regulating valve and throttling valve on the pipeline connected to the inlet of the 2# fan, the stepless regulating valve on the pipe connecting the outlet of the acid system to the inlet of the 1# fan, and the stepless regulation on the air branch pipeline valves and throttle valves.

Specific application examples

Taking the 450m ² sintering machine as an example, the activated coke flue gas purification technology is selected for flue gas treatment. Application example 1: Using the system in Example 1, the sintering flue gas first passes through the heat exchanger in the large sintering flue, and the temperature of the flue gas after heat exchange is 120-140°C; the steam generated by the heat exchanger is used for power generation; After the main exhaust fan, 30% of the flue gas returns to the material surface of the sintering machine, and the remaining 70% of the flue gas enters the activated coke adsorption tower; part of the high-temperature hot air and external cooling air generated during the regeneration process return to the material surface of the sintering machine; the contact method acid system The tail gas produced is returned to the adsorption tower.

Application example 2: using the system in Example 2, mixing the low-temperature flue gas from the wind box at the head part of the sintering machine with the high-temperature flue gas from the wind box at the tail part of the sintering machine (the mixed flue gas volume accounts for 30% of the total flue gas volume), The mixed flue gas returns to the material surface of the sintering machine, and the flue gas from the remaining bellows (the flue gas volume accounts for 70% of the total flue gas volume) enters the sintering large flue, and enters after passing through the electric dust collector, the sintering main exhaust fan and the 1# fan Adsorption tower; part of the high-temperature hot air and exhausted cooling air generated during the regeneration process returns to the material surface of the sintering machine; the tail gas generated by the contact method acid system returns to the adsorption tower.

Comparative Example 1: All the sintering flue gas enters the activated coke adsorption tower, and the high-temperature hot air and external cooling air are all discharged directly; the tail gas produced by the contact method acid production system is directly discharged.

Table 1. Comparison results

It can be seen from Table 1:

1) In application example 1 and application example 2, 30% of the sintering flue gas returns to the material surface of the sintering machine, and 70% of the flue gas enters the activated coke adsorption tower, which can effectively reduce the scale of the active coke purification device, thereby reducing investment by about 40 million Yuan; in application example 2, the scale of the electrostatic precipitator and the sintering main exhaust fan can be reduced at the same time, further reducing the investment;

2) In application example 1 and application example 2, the amount of flue gas treated by the activated coke purification device is reduced, which can reduce the operating cost by about 1.5 yuan/t of sinter;

3) Application example 1 and application example 2 can effectively reduce the total amount of pollutant discharge, as shown in Table 1, if the emission concentration is the same, the amount of flue gas is reduced by 30%, and the total amount of pollutant discharge is reduced by 30%;

4) The steam generated by the heat exchanger in application example 1 is used for power generation, and the power generation capacity is 2-4kW·h/t sinter, which can effectively recover the heat in the sintering flue gas; the high-temperature sintering flue gas in embodiment 2 is returned to the sintering material Surface, can reduce sintering fuel consumption;

5) Application example 1 and application example 2 effectively control the temperature of the flue gas at 120-140°C; it is conducive to the smooth operation of the activated coke flue gas purification device;

6) In Comparative Example 1, the high-temperature hot air and cooling air are directly discharged outside, resulting in energy waste; in Examples 1 and 2, the high-temperature hot air and cooling air are returned to the material surface of the sintering machine, which can reduce the consumption of sintering fuel.

7) In comparative example 1, the tail gas of the contact method acid production system is directly discharged, causing secondary pollution; in application example 1 and application example 2, the tail gas of the contact method acid production system is discharged after being purified by the adsorption tower, which can avoid secondary pollution.

Claims (7)

1. a kind of sintering smoke purifying system of energy-saving and emission-reduction, it is characterised in that the system is A or B；

System A takes out including sintering machine, smoke distributor, sintering motor spindle bellows, sintering machine large flue, electric cleaner, sintering master Blower fan, 1# blower fans, 2# blower fans, adsorption tower, chimney, material transfer equipment and regenerator；Also, the system is in sintering machine large flue Inside it is additionally provided with heat exchanger, sintering machine, sintering motor spindle bellows, sintering machine large flue, electric cleaner, main exhauster of sintering, 1# wind Machine, adsorption tower and chimney are sequentially connected by pipeline, and the circulating flue gas that the outlet of main exhauster of sintering is drawn by branch road Pipeline is connected with 2# fans entrances；

System B takes out including sintering machine, smoke distributor, sintering motor spindle bellows, sintering machine large flue, electric cleaner, sintering master Blower fan, 1# blower fans, 2# blower fans, adsorption tower, chimney, material transfer equipment and regenerator；Also, the system is additionally provided with a dedusting Device, sintering machine are connected with sintering motor spindle bellows by pipeline, sinter the several bellows in head and afterbody number in motor spindle bellows Individual bellows are connected by pipeline with deduster, remaining sintering motor spindle bellows, sintering machine large flue, electric cleaner, sintering master Air exhauster, 1# blower fans, adsorption tower and chimney are sequentially connected by pipeline, and deduster is connected by pipeline with 2# fans entrances；

Wherein, in said system A or B, the smoke distributor is located on sintering pallet, and outlet and the flue gas of 2# blower fans distribute Device is connected by pipeline；The adsorption tower is provided with air inlet and gas outlet, and adsorption tower and regenerator are equipped with charging aperture and discharging Mouthful, discharge outlet of adsorption tower is connected by material transfer equipment with regenerator charging aperture, and adsorption tower charging aperture is set by material conveying It is standby to be connected with regenerator discharging opening；The regenerator is from top to bottom provided with bringing-up section, pumping section and cooling section；Bringing-up section is provided with High-temperature hot-air inlet and outlet, outside are provided with 3# blower fans and hot-blast stove, and high-temperature hot-air import passes through pipeline and hot blast outlet of still phase Even, high-temperature hot-air outlet is connected to 3# fans entrances by pipeline, and 3# fan outlets are connected by pipeline with hot-blast stove import；Again Raw tower pumping section is provided with gas outlet, outside to be provided with contact method acid making system, and the gas access of gas outlet and acid making system passes through pipe Road is connected；Regenerator cooling section is provided with cooling air inlet and outlet, and outside is provided with 4# blower fans, 4# fan outlets and cooling air Import connects；

Described 3# fan outlets set bypass line to be connected with 2# fans entrances, and the cooling air of regenerator cooling section goes out Mouth is connected with 2# fans entrances by pipeline；

Described regeneration tower bottom is additionally provided with vibratory sieve, and vibratory sieve is provided with charging aperture, large granular materials outlet and small particles material Outlet；The discharging opening of regenerator is connected with vibratory sieve charging aperture, and the large granular materials outlet of vibratory sieve passes through material transfer equipment It is connected with adsorption tower charging aperture, the small particles material outlet of vibratory sieve is connected to the sintering machine feed proportioning system outside system；

Described contact method acid making system is provided with gas outlet, and gas outlet is connected to the entrance of 1# blower fans by pipeline.

2. the sintering smoke purifying system of a kind of energy-saving and emission-reduction according to claim 1, it is characterised in that followed in described Step-less adjustment valve is set on ring flue；In the leading point of described circulating flue gas pipeline and described contact method acid making system Step-less adjustment valve is set on the pipeline between gas outlet and 1# fans entrance pipeline tie points；With described adsorption tower air inlet Step-less adjustment valve is set respectively on the pipeline connected with gas outlet；In the pipe that described 3# fan outlets are connected with 2# fans entrances Step-less adjustment valve and choke valve are set on road；Export in the cooling air of described regenerator cooling section and be connected with 2# fans entrances Pipeline on step-less adjustment valve and choke valve are set；It is connected in described contact method acid making system gas outlet with 1# fans entrances Step-less adjustment valve is set on pipeline；At described 2# fans entrances end, the air passage pipeline with air communication is set, and at this Step-less adjustment valve and choke valve are set on pipeline.

3. a kind of sintering gas purifying method of energy-saving and emission-reduction, make use of the system described in claim 1, it is characterised in that bag Include following steps：

1) sintering device flue gas heat utilization

A or b with the following method：

Method a：The sintered motor spindle bellows of high-temperature flue gas enter sintering large flue caused by sintering machine sintering, and flue gas is through heat exchanger Heat exchange, then through electric cleaner, main exhauster of sintering dedusting and pressurization after, part of smoke through 1# blower fans pressurization after enter absorption Tower, remaining flue gas are entered in the pipeline of 2# blower fans front end as circulating flue gas by circulating flue gas pipeline；

Method b：By the low-temperature flue gas of sintering machine head portion bellows and the high-temperature flue gas access tube of sintering machine tail portion bellows Mixing is used as circulating flue gas in road, enters by deduster dedusting in the pipeline of 2# blower fans front end, and the flue gas of remaining bellows enters Large flue is sintered, enters adsorption tower after the pressurization of electric cleaner dedusting, main exhauster of sintering and 1# blower fans；

2) adsorption tower adsorbs

The sintering flue gas being transported in adsorption tower, is contacted with the activated coke inside adsorption tower so that the pollutant in flue gas Adsorbed by activated coke, the flue gas after purification is through smoke stack emission；

3) activated coke regenerates

The activated coke for having adsorbed pollutant is transferred to regenerator from adsorption tower, and activated coke is entered by the top of regenerator, heated Regenerated after section, pumping section and cooling section processing, finally reach regeneration tower bottom；

In bringing-up section：It is heated to 400~470 DEG C of high-temperature hot-air through hot-blast stove from regenerator bringing-up section side to enter, with flowing through The activated coke of bringing-up section carries out not contact heat-exchanging and heats activated coke, and high-temperature hot-air temperature is changed into 300~350 DEG C, then from adding The opposite side output of hot arc；Before high-temperature hot-air after part heat exchange enters 2# blower fans as outer thermal wind exhausting after the pressurization of 3# blower fans In the pipeline at end, another part returns to that hot-blast stove is heated is used again as high-temperature hot-air；

In pumping section：Activated coke caused high SO in bringing-up section regenerative process₂Concentration gases are discharged into contact method by pumping section Acid making system extracting sulfuric acid, tail gas caused by acid making system extracting sulfuric acid enters adsorption tower after the pressurization of 1# blower fans, in tail gas The pollutant contained is adsorbed the activated coke Adsorption in tower, and the tail gas being purified is discharged by chimney；

In cooling section：Normal temperature air as cooling air enters after the pressurization of 4# blower fans from the side of regenerator cooling section, with The activated coke for flowing through cooling section carries out not contact heat-exchanging, and after activated coke is cooled down, cooling air is warming up to 80~120 DEG C, outer row Into in the pipeline of 2# blower fans front end；

Activated coke after regeneration is discharged into vibratory sieve by regenerator, and particle diameter >=1.5mm activated coke particle, which returns, after screening inhales Attached tower works on, and sintering machine feed proportioning system is entered after particle diameter ＜ 1.5mm activated coke powder collection, as raw materials for sintering again Utilize；

Above-mentioned steps 1) in caused circulating flue gas and step 3) outer caused by outer thermal wind exhausting caused by bringing-up section, cooling section After row's cooling air is mixed to form mixed flue gas in the pipeline of 2# fans entrances front end, pressurizeed into 2# blower fans, then by cigarette Qi leel orchestration, finally return that sintering machine charge level participates in sintering process, also, before should controlling into smoke distributor in mixed flue gas Oxygen content, such as oxygen content deficiency, the choke valve and step-less adjustment valve on air passage pipeline should be opened, by sucking air Adjust oxygen content.

A kind of 4. sintering gas purifying method of energy-saving and emission-reduction according to claim 3, it is characterised in that the step 1) Method a in, heat exchange amount is adjusted by adjusting in heat exchanger water-carrying capacity, to ensure the flue-gas temperature into adsorption tower as 120 ~140 DEG C；The exhaust gas volumn into adsorption tower is controlled to account for the 50%~80% of total sintering exhaust gas volumn simultaneously, into before 2# fans entrances The amount of circulating gas at end accounts for the 20%~50% of total sintering exhaust gas volumn；

Steam or hot water are produced after heat exchanger exchanges heat to be used as thermal source.

A kind of 5. sintering gas purifying method of energy-saving and emission-reduction according to claim 3, it is characterised in that the step 1) Method b in, by adjusting the number of cerebral cryotherapy bellows and afterbody high temperature bellows, with ensure into adsorption tower flue-gas temperature For 120~140 DEG C；The exhaust gas volumn into adsorption tower is controlled to account for the 50%~80% of total sintering exhaust gas volumn simultaneously, into 2# blower fans The amount of circulating gas of entrance front end accounts for the 20%~50% of total sintering exhaust gas volumn.

A kind of 6. sintering gas purifying method of energy-saving and emission-reduction according to claim 3, it is characterised in that institute in step 3) Before the mixed flue gas stated enters smoke distributor, oxygen content should account for more than the 15% of mixed flue gas volume.

A kind of 7. sintering gas purifying method of energy-saving and emission-reduction according to claim 3, it is characterised in that methods described In, the flow of different gas in pipelines can be adjusted by the step-less adjustment valve that is arranged on pipeline and choke valve, to ensure not With the pressure balance in pipeline.