Standby system applicable to coke oven flue gas purification

Abstract

The utility model discloses a standby system suitable for coke oven flue gas purification, which comprises an electric shut-off valve a, an electric shut-off valve b, a desulfurizing agent conveying pipeline, a flue reactor, a bag-type dust collector, a denitration reactor, an induced draft fan and a chimney, the desulfurizing agent conveying pipeline comprises a desulfurizing agent conveying pipeline I and a desulfurizing agent conveying pipeline II, 1 # coke oven flue gas and 2 # coke oven flue gas respectively enter the two flue gas reaction channels through the electric shut-off valve a and the electric shut-off valve b, and a desulfurizing agent is respectively conveyed into the two flue gas reaction channels through the desulfurizing agent conveying pipeline I and the desulfurizing agent conveying pipeline II; compared with the prior art, the flue gas desulfurization device has the advantages that the sedimentation of dust and a desulfurizing agent can be avoided, the utilization rate of the desulfurizing agent is greatly increased, the material consumption is reduced, and the maintenance is convenient.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of flue gas purification, and more particularly to a standby system for coke oven flue gas desulfurization and denitrification and dust removal. BACKGROUND

[0002] According to GB16171-2024 "Coke Chemical Industry Atmospheric Pollutant Discharge Standard" 4.2, "waste gas collection and treatment system should be operated synchronously with production process equipment, waste gas collection and treatment system fails or is under repair, corresponding production process equipment should stop running, and synchronous use after troubleshooting or repair is completed; production process equipment cannot stop running or cannot stop running in time, waste gas emergency treatment facilities should be set or other alternative measures should be taken", that is, the requirement of environmental protection facilities and coke oven synchronous operation rate is 100%.

[0003] To solve this phenomenon, many coking enterprises add a set of environmental protection device as standby, which is equivalent to reforming on the basis of the existing flue gas environmental protection device and constructing a completely independent desulfurization and denitrification equipment in parallel, when one of the environmental protection devices fails, the standby device can be switched to, realizing the complete synchronization of environmental protection device and coke oven production.

[0004] In recent years, with the development of dry desulfurization technology, due to its high efficiency, low temperature drop, small investment, convenient use and other characteristics, it has been applied in a large number of coke oven flue gas ultra-low emission projects.

[0005] The dry desulfurization process generally uses a fan to directly spray desulfurizing agent such as baking soda into the flue through the conveying pipeline, and reacts with SO2 in the flue gas, and the desulfurization efficiency can reach more than 95%; the mixing uniformity and residence time of desulfurizing agent and flue gas are the most critical factors to ensure the desulfurization efficiency.

[0006] Because the coke oven is generally two in a group, the original national environmental protection requirement is low, so the desulfurization and denitrification device is generally a device after subsequent transformation, and in general, the flue gas of two furnaces is mixed after being connected respectively, and then sent to the desulfurization and denitrification device for purification; therefore, once the environmental protection facility fails, the whole environmental protection device cannot operate normally, which causes the outlet pollutant discharge to exceed the standard, and the coke oven cannot operate normally.

[0007] In order to solve the phenomenon of coke oven shutdown caused by equipment failure, many coking enterprises add an independent environmental protection device as a standby system.

[0008] Because the new standby system must be standby on line, otherwise, once the environmental protection equipment fails, it needs to consume a long time to restart another set of facilities, so generally each set of environmental protection facilities corresponds to a coke oven flue gas, on line standby, when a set of equipment fails, the flue gas of two coke ovens is switched to another set of system, so each set of environmental protection device not only meets the environmental protection standard of single coke oven flue gas, but also meets the standard emission after the flue gas of two coke ovens enters the device.

[0009] It also needs to be explained that when only one set of environmental protection equipment is operated for a long time, the filter bag, bag cage, SCR catalyst, ammonia injection equipment and bag shell of the standby device are easy to be corroded by dewing due to smoke entering, especially the filter bag and catalyst are easy to be blocked and caked, which seriously affects the service life of the equipment.

[0010] Therefore, according to the above, the flue size and dust collector selection of the new standby system must be designed according to the flue gas amount of two coke ovens, and the actual operation is basically one coke oven corresponding to one set of environmental protection system.

[0011] In the actual equipment operation, many problems are found.

[0012] 1. Serious ash deposition in the flue;

[0013] The flue size is designed according to the flue gas amount of two coke ovens, so when a single coke oven is operated, the flue gas flow rate is too low, and a large amount of dust deposits at the bottom of the flue. Because the coke oven dust is sticky and the flue gas contains a large amount of moisture, the ash is difficult to remove after a long time.

[0014] 2. Large amount of desulfurizing agent;

[0015] Dry desulfurizing agent sodium bicarbonate particles (usually particle size is 20 μm) need to be kept in a suspended state in the flue to react with SO2 in the flue gas. When normally designed, the flow rate of 10~15 m / s can provide sufficient air flow carrying capacity to ensure sufficient reaction time of pollutants in the flue gas and desulfurizing agent. When the environmental protection facility only purifies the flue gas amount of a single coke oven, because the flow rate is low, sodium bicarbonate is easy to settle in the flue, which leads to low utilization rate of desulfurizing agent and increased consumption. SUMMARY

[0016] The purpose of the utility model is to solve the problems in the prior art, and a standby system suitable for coke oven flue gas purification is proposed, which can avoid dust and desulfurizing agent settlement, greatly improve the utilization rate of desulfurizing agent and reduce material consumption.

[0017] To achieve the above object, the utility model provides a kind of standby system suitable for coke oven flue gas purification, including electrically operated closing valve a, electrically operated closing valve b, desulfurizer conveying pipeline, flue reactor, bag filter, denitration reactor, induced draft fan and chimney, the flue reactor includes the flue with two independent flue gas reaction passages inside, the desulfurizer conveying pipeline includes desulfurizer conveying pipeline I and desulfurizer conveying pipeline II, 1# and 2# coke oven flue gas respectively through electrically operated closing valve a and electrically operated closing valve b respectively enters two flue gas reaction passages, desulfurizer is conveyed into two flue gas reaction passages by desulfurizer conveying pipeline I and desulfurizer conveying pipeline II respectively, and desulfurization reaction occurs with flue gas mixing, flue gas after desulfurization reaction enters bag filter, flue gas after dust removal enters denitration reactor and carries out denitration reaction, and finally clean flue gas is sucked by induced draft fan and is discharged into atmosphere through chimney.

[0018] As preferred, the flue is provided with a vertical partition plate inside to divide its inside into two completely independent flue gas reaction passages, and the two flue gas reaction passages are respectively left flue gas reaction passage and right flue gas reaction passage.

[0019] As preferred, at least two nozzles are provided on the desulfurizer conveying pipeline I and desulfurizer conveying pipeline II to spray desulfurizer into the right flue gas reaction passage and left flue gas reaction passage respectively.

[0020] As preferred, the bag filter adopts bottom air inlet, and an adjusting valve is arranged on the air inlet flue of each compartment of the bag filter.

[0021] The utility model has the advantages that: 1. Electrically operated closing valves are arranged on the branch flues before two coke oven flues enter the flue reactor, so that the entry and closing of the flue gas of each coke oven can be controlled individually;

[0022] 2. The flue reactor adopts a flue with two flue gas reaction passages inside, so that the flue gas of each coke oven passes through the corresponding flue gas reaction passage, avoiding the problem that when a single coke oven is operated, the flue gas passes through a flue with a size designed according to the flow rate of two coke ovens, causing the flow rate of flue gas to be too low, ensuring that the flow rate of flue gas is 10-15 m / s, greatly improving the utilization rate of desulfurizer and avoiding dust and desulfurizer settlement;

[0023] 3. The two flue gas reaction passages adopt independent desulfurizer conveying pipelines, so that the conveying amount of desulfurizer can be controlled more accurately, and the consumption of materials is less;

[0024] 4. The flue is vertically separated, so that maintenance personnel can easily enter the flue to perform ash cleaning, maintenance and other operations.

[0025] The features and advantages of the utility model will be described in detail with reference to the embodiments and the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a structure schematic diagram of a standby system suitable for coke oven flue gas purification;

[0027] Figure 2 is a flue reactor structure schematic diagram.

[0028] In the figure: 1-electrically operated shut-off valve a, 2-electrically operated shut-off valve b, 3-desulfurizing agent conveying pipeline, 4-flue reactor, 5-bag-type dust collector, 6-denitration reactor, 7-induced draft fan, 8-chimney, 3-1-desulfurizing agent conveying pipeline I, 3-2-desulfurizing agent conveying pipeline II, 3-3-nozzle, 4-1-left flue gas reaction channel, 4-2-right flue gas reaction channel, 4-3-flue, 4-4-vertical partition plate. DETAILED DESCRIPTION

[0029] Referring to Figure 1 , Figure 2 , the utility model relates to a standby system suitable for coke oven flue gas purification, including electrically operated shut-off valve a1, electrically operated shut-off valve b2, desulfurizing agent conveying pipeline 3, flue reactor 4, bag-type dust collector 5, denitration reactor 6, induced draft fan 7 and chimney 8, the flue reactor 4 includes the flue 4-3 with two flue gas reaction channels inside, the desulfurizing agent conveying pipeline 3 includes desulfurizing agent conveying pipeline I 3-1 and desulfurizing agent conveying pipeline II 3-2, and the flue gas of 1# and 2# coke oven passes through electrically operated shut-off valve a1 and electrically operated shut-off valve b2 respectively and enters two flue gas reaction channels, and the desulfurizing agent is conveyed into two flue gas reaction channels through desulfurizing agent conveying pipeline I 3-1 and desulfurizing agent conveying pipeline II 3-2 respectively, mixes with flue gas and carries out desulfurization reaction, and the flue gas after desulfurization reaction enters bag-type dust collector 5, carries out dust removal, and the flue gas after dust removal enters denitration reactor 6 and carries out denitration reaction, and finally the clean flue gas is sucked through chimney 8 by induced draft fan 7 and is discharged into the atmosphere.

[0030] The flue 4-3 is equipped with vertical partition plate 4-4 and is symmetrically divided into two completely independent flue gas reaction channels, and the two flue gas reaction channels are left flue gas reaction channel 4-1 and right flue gas reaction channel 4-2 respectively.

[0031] Desulfurizing agent conveying pipeline I 3-1 and desulfurizing agent conveying pipeline II 3-2 are all equipped with at least two nozzles 3-3 for spraying desulfurizing agent into right flue gas reaction channel 4-2 and left flue gas reaction channel 4-1 respectively.

[0032] The bag-type dust collector 5 adopts bottom air inlet, and an adjusting valve is arranged on the air inlet flue of each compartment of the bag-type dust collector 5.

[0033] The utility model works as follows:

[0034] The utility model discloses a kind of standby systems suitable for coke oven flue gas purification, during working process, open electric shut-off valve a1 and electric shut-off valve b2, 1# and 2# coke oven flue gas respectively through electric shut-off valve a1 and electric shut-off valve b2 respectively into two flue gas reaction channels, desulfurizer is sprayed into right flue gas reaction channel 4-2 and left flue gas reaction channel 4-1 respectively by nozzle 3-3 on desulfurizer conveying pipeline I3-1 and desulfurizer conveying pipeline II3-2, and mixed with flue gas, desulfurization reaction occurs, flue gas after desulfurization reaction enters bag filter 5 again, flue gas after dust removal enters denitration reactor 6 and carries out denitration reaction, finally clean flue gas is sucked by induced draft fan 7 and is discharged into atmosphere through chimney 8.

[0035] Vertical partition 4-4 is arranged in flue 4-3, which symmetrically divides the inside into two completely independent flue gas reaction channels, no matter flue gas is from single side or double side, because bottom inlet is used in bag filter 5, adjusting valve is arranged on each chamber inlet flue, so that inlet flue gas amount can be adjusted, and bag flushing caused by uneven single side inlet can be avoided, airflow will not have great impact on filter bag, so as to affect filter bag life.

[0036] Flue reactor 4 is divided into left and right, instead of up and down, which is more conducive to maintenance personnel to enter flue and carry out patrol, ash removal operation.

[0037] The above embodiment is a description of the utility model, not a limitation of the utility model, and any simple transformation of the utility model belongs to the protection scope of the utility model.

Claims

1. A stand-by system for the purification of coke oven flue gases, characterized by: It includes electrically operated closing valve a (1), electrically operated closing valve b (2), desulfurizer conveying pipeline (3), flue reactor (4), bag filter (5), denitration reactor (6), induced draft fan (7) and chimney (8), the flue reactor (4) includes the flue (4-3) with two independent flue gas reaction channels inside, the desulfurizer conveying pipeline (3) includes desulfurizer conveying pipeline I (3-1) and desulfurizer conveying pipeline II (3-2), 1# and 2# coke oven flue gas respectively enters two flue gas reaction channels through electrically operated closing valve a (1) and electrically operated closing valve b (2) respectively, desulfurizer is respectively conveyed into two flue gas reaction channels through desulfurizer conveying pipeline I (3-1) and desulfurizer conveying pipeline II (3-2), mixes with flue gas and occurs desulfurization reaction, after desulfurization reaction, flue gas enters bag filter (5), after dust removal, flue gas enters denitration reactor (6) and carries out denitration reaction, finally, clean flue gas is sucked by induced draft fan (7) and is discharged into atmosphere through chimney (8).

2. A stand-by system for the purification of coke oven flue gases as claimed in claim 1, characterized in that: The flue (4-3) is provided with vertical partition (4-4) and is symmetrically divided into two flue gas reaction channels inside, the two flue gas reaction channels are left flue gas reaction channel (4-1) and right flue gas reaction channel (4-2) respectively.

3. A stand-by system for the purification of coke oven flue gases according to claim 2, characterized in that: Desulfurizer conveying pipeline I (3-1) and desulfurizer conveying pipeline II (3-2) are all provided with at least two nozzles (3-3) for respectively spraying desulfurizer into right flue gas reaction channel (4-2) and left flue gas reaction channel (4-1).

4. A stand-by system for the purification of coke oven flue gases according to any one of claims 1 to 3, characterized in that: The bag filter (5) adopts bottom air inlet, and each compartment of the bag filter (5) is provided with an adjusting valve.

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