Dry quenching diffused gas desulfurization system and method

Abstract

The invention discloses a dry quenching diffused gas desulfurization system. The system comprises a desulfurizer, a dust remover, a booster fan and a chimney which are sequentially communicated through a pipeline, an inlet of the desulfurizer is communicated with a dry quenching diffused gas inlet pipeline, and an inlet SO2 concentration measuring instrument and inlet flue gas flow detection equipment are arranged on the dry quenching diffused gas inlet pipeline; at least one feeding position is arranged in the desulfurizer along the flowing direction of fluid, a spray head for spraying a desulfurizing agent is arranged on the feeding position, and the spray head is communicated with an external desulfurizing agent supply pipeline; and an SO2 concentration measuring instrument is arranged in the chimney. The invention also discloses a dry quenching diffused gas desulfurization method. The desulfurization device has the beneficial effects that the desulfurizer is provided with at least one feeding position, the feeding amount of a desulfurizing agent is adjusted for desulfurization according to the flow of the dry quenching diffused gas and the concentration of SO2, the temperature of the dry quenching diffused gas is not reduced and the air volume of the system is not increased during desulfurization, and the subsequent waste heat recovery is not influenced.

Description

Technical Field

[0001] The invention relates to the technical field of waste gas treatment, and in particular to a system and method for desulfurizing coke dry quenching exhaust gas. Background Art

[0002] CDQ exhaust gas mainly refers to the waste gas that needs to be discharged regularly due to the high oxygen content in the circulating nitrogen during the coke quenching process. The waste gas contains a large amount of heat, dust and SO 2 , it needs to be treated to meet the emission standards.

[0003] Existing CDQ vent gas treatment processes include SDS desulfurization + dust removal process, circulating fluidized bed + dust removal process and activated carbon desulfurization process. When these processes treat CDQ vent gas, it is difficult to deal with the SO generated in the vent gas due to the change of coke sulfur content. 2 Fluctuations in concentration cause high material consumption in the operation of desulfurization facilities, SO 2 In order to solve this problem, some coking enterprises introduce part of the unorganized exhaust gas from the CDQ area into the exhaust gas, and use the unorganized exhaust gas to dilute the CDQ exhaust gas to balance the SO 2 concentration, reducing SO in flue gas 2 The impact of concentration fluctuations on emissions. Although this method has increased the SO 2 The qualified rate of emission is improved, but there are still the following limitations: (1) The introduction of a large amount of cold air reduces the temperature of the CDQ exhaust gas, resulting in the lack of recovery value of the heat of the CDQ exhaust gas; (2) The flue gas volume is increased, the scale of the flue gas purification device needs to be increased, the primary investment increases, and the energy consumption of the booster fan is increased due to the large selection; (3) The flue gas temperature is reduced, the desulfurization efficiency is difficult to stabilize, the desulfurization agent consumption is large, the desulfurization by-products increase, and the disposal cost increases. Summary of the invention

[0004] The object of the present invention is to provide a system and method for desulfurizing the discharged gas from dry coke quenching, aiming at desulfurizing the discharged gas from dry coke quenching without lowering the temperature of the discharged gas from dry coke quenching.

[0005] The technical solution adopted by the present invention is: a CDQ vent gas desulfurization system, comprising a desulfurizer, a dust collector, a booster fan and a chimney which are sequentially connected through pipelines; The inlet of the desulfurizer is connected to the dry quenching vent gas inlet pipeline, and the dry quenching vent gas inlet pipeline is provided with an inlet SO 2 Concentration measuring instrument and inlet smoke flow detection equipment; At least one dosing position is arranged in the desulfurizer along the fluid flow direction, and a nozzle for spraying the desulfurizer is arranged on the dosing position, and the nozzle is connected to an external desulfurizer supply pipeline; The chimney is provided with an outlet SO2 Concentration measuring instrument.

[0006] According to the above scheme, the desulfurizer includes a shell, which is provided with an inlet and an outlet; at least one vertical guide plate is provided in the shell, and the guide plate divides the interior of the shell into a plurality of areas connected in sequence; an addition position is provided in each area, and the nozzles on each addition position are respectively connected to the corresponding desulfurizer supply pipeline, and each desulfurizer supply pipeline is separately equipped with a regulating valve.

[0007] According to the above solution, any two adjacent areas in the shell are connected via a connecting port; the positions of the two adjacent connecting ports are opposite.

[0008] According to the above scheme, two vertical guide plates are used to divide the shell into three areas from left to right, and a gap is left between the top or bottom of the guide plate and the shell to form a connecting port connecting two adjacent areas; the connecting port between the left area and the middle area is located at the bottom, and the connecting port between the middle area and the right area is located at the top.

[0009] According to the above scheme, in the first area of ​​the desulfurizer along the fluid flow direction, the desulfurizer spraying direction is opposite to the flow direction of the CDQ gas; in other areas, the desulfurizer spraying direction is the same as the flow direction of the CDQ gas.

[0010] According to the above scheme, a heat exchanger is arranged between the dust collector and the booster fan, the outlet of the dust collector is connected to the heat source inlet of the heat exchanger through a pipeline, and the heat source outlet of the heat exchanger is connected to the inlet of the booster fan through a pipeline.

[0011] According to the above scheme, the CDQ vent gas desulfurization system is also provided with a controller, which is respectively connected to each regulating valve, the inlet SO 2 Concentration measuring instrument, inlet flue gas flow measuring instrument and outlet SO 2 Connected to concentration measuring instrument.

[0012] The present invention also adopts a method for desulfurization of coke dry quenching gas, which comprises: Provide the CDQ vent gas desulfurization system as described above; detect the inlet flow rate and SO 2 After the inlet concentration reaches 1.000, the CDQ exhaust gas enters the desulfurizer and is sprayed with desulfurizer. The desulfurizer reacts with SO in the CDQ exhaust gas. 2 The desulfurization is carried out by reaction; the CDQ exhaust gas after desulfurization is dedusted by the dust collector and then enters the heat exchanger to recover the waste heat. After the temperature is reduced, it enters the chimney under the action of the booster fan; the SO at the chimney outlet is detected 2 The outlet concentration of CDQ exhaust gas is calculated based on the inlet flow rate, SO 2 The inlet concentration and SO 2The outlet concentration is calculated, the real-time desulfurization rate is calculated, and the desulfurization agent distribution and addition scheme is selected according to the desulfurization rate. The desulfurization agent is added to reduce the SO 2 The outlet concentration meets the emission standards.

[0013] According to the above scheme, the desulfurizer distribution and addition scheme is: When 0≤ω<20%, ​​the dosage of desulfurizer at the first addition position is 0~15% of the total dosage of desulfurizer, the dosage of desulfurizer at the second addition position is 85%~100% of the total dosage of desulfurizer, and the dosage of desulfurizer at the third addition position is 0; When 20%≤ω<50%, the dosage of desulfurizer at the first dosing position is 15~30% of the total dosage of desulfurizer, the dosage of desulfurizer at the second dosing position is 70%~85% of the total dosage of desulfurizer, and the dosage of desulfurizer at the third dosing position is 0; When 50%≤ω<80%, the dosage of desulfurizer at the first dosing position is 15%~30% of the total dosage of desulfurizer, the dosage of desulfurizer at the second dosing position is 35%~65% of the total dosage of desulfurizer, and the dosage of desulfurizer at the third dosing position is 15%~30% of the total dosage of desulfurizer; When 80%≤ω<99.9%, the desulfurizer dosage at the first addition position is 20~35% of the total desulfurizer dosage, the desulfurizer dosage at the second addition position is 30%~40% of the total desulfurizer dosage, and the desulfurizer dosage at the third addition position is 20~35% of the total desulfurizer dosage.

[0014] According to the above scheme, the desulfurization rate ω is calculated by the following formula: ω = (C 1 -C 3 )×100% / C 1 ; Total dosage of desulfurizer M 2 Calculated by the following formula: M 2 =M 1 ×2.76; M 1 =Q 1 ×(C 1 -C 2 ); In the above formula, C 1 For SO 2 The inlet concentration is in mg / Nm 3 ;Q 1 The standard flow rate of CDQ exhaust gas inlet flue gas, in Nm 3 / h; C 2 To meet the control target concentration of emission standards, the unit is mg / Nm 3 ;M1 is the SO that needs to be removed from the CDQ exhaust gas per unit time 2 Mass, in mg / h; C 3 For SO 2 The outlet concentration is in mg / Nm 3 .

[0015] The beneficial effects of the present invention are: 1. The desulfurizer in the system of the present invention is provided with at least one dosing position, and the flow rate of the CDQ vent gas and SO 2 The concentration of the desulfurizer is adjusted to adjust the dosage of the desulfurizer to desulfurize the CDQ vent gas. This desulfurization system will not reduce the temperature of the CDQ vent gas and increase the system air volume while desulfurizing, will not affect the subsequent waste heat recovery, and does not require an increase in the desulfurization scale or increase in desulfurization by-products.

[0016] 2. In the present invention, the desulfurizer is divided into zones to set the dosing positions, and the dosing amount at different dosing positions is adjusted according to the real-time desulfurization rate of the system, thereby improving the desulfurization efficiency and reducing the consumption of the desulfurizer.

[0017] 3. The present invention arranges a fin-type heat exchanger to realize the utilization of the waste heat of the CDQ flue gas, thereby effectively recovering the heat of the CDQ flue gas.

[0018] 4. The present invention is provided with an anti-static ceramic tube dust collector, which realizes high-temperature dust removal by dry quenching and dispersing flue gas, saving land and one-time investment; a shutter air inlet distributor is arranged in the dust collector to avoid direct impact of high-temperature flue gas on the ceramic tube dust collector, thereby reducing the wear of the dust collector.

[0019] 5. The method of the present invention detects SO in the CDQ exhaust gas in real time during the desulfurization process. 2 Concentration, by real-time calculation of desulfurization rate to select the appropriate desulfurizer dosing plan, compared with the traditional desulfurizer speculative plan, the use of multi-point addition can effectively avoid the blockage and wear of the nozzle caused by the dosage change of the addition point, which is beneficial to the full dispersion of the desulfurizer in the flue; the first addition point is designed to adopt reverse spraying, and the second and third addition points are designed to adopt forward spraying to increase the primary desulfurization reaction time and reduce the secondary and tertiary desulfurization loads, which is beneficial to improve the desulfurization efficiency of the desulfurizer and reduce the desulfurization agent consumption, thereby realizing the dynamic use of the desulfurizer, fully dispersing, improving the desulfurization efficiency, reducing the use of the desulfurizer and reducing the desulfurization ash production and disposal costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of embodiment 1 of the present invention.

[0021] Among them: 1. Controller; 2. Desulfurizer; 2.1. Left area; 2.2. Middle area; 2.3. Right area; 3. Dust collector; 4. Heat exchanger; 5. Booster fan; 6. Chimney; 7. CDQ exhaust gas inlet pipeline; 8. Inlet SO 2 Concentration measuring instrument; 9, nozzle; 10, regulating valve; 11, guide plate; 12, air inlet distributor; 13, ceramic tube; 14, cold source channel; 15, cold source outlet pipeline; 16, outlet SO 2 Concentration measuring instrument. DETAILED DESCRIPTION

[0022] In order to better understand the present invention, the present invention is further improved in combination with the accompanying drawings and specific embodiments.

[0023] like Figure 1 The CDQ vent gas desulfurization system shown in the figure comprises a desulfurizer 2, a dust collector 3, a booster fan 5 and a chimney 6 which are connected in sequence through pipelines; the inlet of the desulfurizer 2 is connected to the CDQ vent gas inlet pipeline 7, and the CDQ vent gas inlet pipeline 7 is provided with an inlet SO 2 concentration measuring instrument 8 and inlet flue gas flow measuring instrument; at least one dosing position (for dosing desulfurizer) is arranged in the desulfurizer 2 along the fluid flow direction, and a nozzle for spraying desulfurizer is arranged on the dosing position, and the nozzle is connected to the external desulfurizer supply pipeline, and a regulating valve 10 is arranged on the desulfurizer supply pipeline; the chimney 6 is provided with an outlet SO 2 Concentration measuring instrument 16.

[0024] In the present invention, the CDQ vent gas enters the desulfurizer 2, and the desulfurizer is sprayed through the nozzle in the desulfurizer 2. The desulfurizer reacts with SO in the CDQ vent gas. 2 reaction to achieve desulfurization; the CDQ exhaust gas after desulfurization is dedusted by the dust collector 3 and then discharged into the chimney 6 under the action of the booster fan 5.

[0025] Preferably, the desulfurizer 2 includes a shell, which is provided with an inlet and an outlet, and the shell inlet is connected to the CDQ vent gas inlet pipeline 7; at least one guide plate 11 is provided in the shell, and the guide plate 11 divides the interior of the shell into a plurality of areas connected in sequence; an addition position is provided in each area, and the nozzles 9 on each addition position are respectively connected to the corresponding desulfurizer supply pipeline, and each desulfurizer supply pipeline is separately configured with a regulating valve 10.

[0026] In the present invention, the CDQ exhaust gas enters the shell through the inlet (the inlet is arranged at the upper part of the shell), flows through each area in sequence, and then flows out from the outlet of the shell.

[0027] Preferably, any two adjacent areas in the shell are connected via a connecting port; and positions of the two adjacent connecting ports are opposite.

[0028] The guide plates 11 are sequentially arranged in the housing along the fluid flow direction, and the number of the separated areas is one more than the guide plates 11. Figure 1 As shown, two vertical guide plates 11 are used to separate the shell into three areas from left to right, specifically including the left area 2.1, the middle area 2.2 and the right area 2.3; a gap is left between the top or bottom of the guide plate 11 and the shell to form a connecting port connecting two adjacent areas; the connecting port between the left area 2.1 and the middle area 2.2 is located at the bottom, and the connecting port between the middle area 2.2 and the right area 2.3 is located at the top. In the present invention, the connecting ports of two adjacent areas can also be designed on the front and rear sides.

[0029] Preferably, in the first area of ​​the desulfurizer 2 along the fluid flow direction, the desulfurizer spraying direction is opposite to the flow direction of the CDQ gas; in other areas, the desulfurizer spraying direction is the same as the flow direction of the CDQ gas.

[0030] Specifically, the CDQ exhaust gas flows from left to right into the three areas of the desulfurizer 2. In the left area 2.1, the exhaust gas flows from top to bottom. The spraying direction of the desulfurizer in this area is upward (the nozzle sprays upward), which is opposite to the flow direction of the CDQ exhaust gas (downward). In the middle area 2.2 and the right area 2.3, the spraying direction of the desulfurizer is the same as the flow direction of the CDQ exhaust gas in these two areas.

[0031] Preferably, the nozzle is installed in the middle of the corresponding area.

[0032] In the present invention, the shell is formed by connecting an upper cylindrical structure and a lower conical structure, and each area is arranged in the cylindrical structure; an ash hopper is arranged at the bottom of the conical structure for discharging ash.

[0033] Preferably, a heat exchanger 4 is arranged between the dust collector 3 and the booster fan 5, the outlet of the dust collector 3 is connected to the heat source inlet of the heat exchanger 4 through a pipeline, and the heat source outlet of the heat exchanger 4 is connected to the inlet of the booster fan 5 through a pipeline.

[0034] In the present invention, the heat exchanger 4 is a fin-type heat exchanger 4. The cold source channel 14 of the heat exchanger 4 is connected to the cold source inlet pipeline and the cold source outlet pipeline 15 respectively, superheated water flows in the cold source channel 14, and the high-temperature dry coke quenching purified gas after desulfurization and dust removal flows outside the heat exchanger 4. The superheated water exchanges heat with the high-temperature dry coke quenching purified gas to realize waste heat recovery, and the recovered waste heat is sent to subsequent processes for use.

[0035] In the present invention, the dust collector 3 is a ceramic tube dust collector. The filter material of the dust collector 3 is composed of a ceramic tube 13 externally connected to an anti-static conductive wire. An ash hopper and a level meter are arranged at the bottom of the dust collector 3. The dust collector 3 is provided with a cleaning pulse valve of a conventional dust collector, and compressed air or nitrogen is provided for cleaning and pneumatic ash conveying respectively. The above-mentioned structure and function of the ceramic tube dust collector are all prior arts and will not be repeated here.

[0036] Preferably, an air intake distributor 12 is provided at the inlet end of the dust collector 3, and the air intake distributor 12 is a shutter air intake distributor; the setting of the air intake distributor 12 can prevent the high-flow rate of CDQ exhaust gas from directly impacting the dust collector and causing wear, thereby extending the life of the dust collector 3.

[0037] In the present invention, a discharge device is arranged at the bottom of the air inlet distributor 12, and the discharge structure adopts a ash hopper combined with a spiral feeder design to avoid a large amount of desulfurization agent accumulation causing an increase in the load-bearing capacity of the desulfurization system and reduce the risk of collapse of the dust removal system; this is the prior art and will not be described in detail here.

[0038] Preferably, the CDQ vent gas desulfurization system is further provided with a controller 1, which is respectively connected to each regulating valve 10, the inlet SO 2 Concentration measuring instrument 8, inlet flue gas flow measuring instrument and outlet SO 2 The concentration measuring instrument 16 is connected.

[0039] In the present invention, the inlet SO2 concentration measuring instrument 8 is used to detect SO 2 The inlet concentration (SO before entering desulfurizer 2) 2 concentration), outlet SO 2 Concentration measuring instrument 16 is used to detect SO in real time 2 The outlet concentration (i.e., SO at the chimney 6 outlet) 2 concentration); the inlet flue gas flow meter is used to detect the flow of CDQ exhaust gas entering the desulfurizer 2 in real time; each detection device transmits the detected data to the controller 1, the controller 1 receives the data measured by each measuring instrument, calculates the desulfurization rate, and adjusts the dosage of the desulfurizer at each dosage position by controlling the regulating valve 10.

[0040] The present invention sets an inlet flue gas flow meter and an inlet SO 2 Concentration measuring instrument 8, each measuring instrument shall be arranged on a horizontal pipeline in accordance with the national standard for the installation of flue gas measuring equipment, with four in front and two in the back, and the pipeline shall be well insulated; the outlet of chimney 6 shall be set with outlet SO 2 Concentration measuring instrument 16.

[0041] A method for desulfurizing coke dry quenching exhaust gas, the method comprising: Providing a CDQ vent gas desulfurization system as described above; Detect the inlet flow rate and SO of CDQ exhaust gas 2 After the inlet concentration reaches 1.00, the CDQ exhaust gas enters the desulfurizer 2, where the desulfurizer is sprayed to detect the SO in the CDQ exhaust gas in real time. 2 concentration, the controller 1 program has a built-in formula to calculate the desulfurization amount and real-time desulfurization rate, and then selects a suitable desulfurization agent addition scheme, and controls the addition amount of each addition point through the regulating valve 10, so that the SO in the CDQ released gas is 2 The outlet concentration meets the emission standards.

[0042] In the present invention, specifically, the inlet flow rate of CDQ exhaust gas and SO 2 After the inlet concentration reaches 1.5, the CDQ exhaust gas enters the desulfurizer 2, where the desulfurizer is sprayed. The desulfurizer reacts with the SO 2 The desulfurization is carried out by reaction; the CDQ exhaust gas after desulfurization is dedusted by dust collector 3 and then enters heat exchanger 4 to recover waste heat. After the temperature is reduced, it enters chimney 6 under the action of booster fan 5; SO 2 The outlet concentration of CDQ exhaust gas is calculated based on the inlet flow rate, SO 2 The inlet concentration and SO 2 The outlet concentration of the CDQ is calculated, the desulfurization rate and the total dosage of the desulfurizer are calculated, and the desulfurizer distribution and dosage scheme is selected according to the desulfurization rate and the desulfurizer is added to reduce the SO 2 The outlet concentration meets the emission standards.

[0043] In the present invention, a desulfurizer distribution and addition plan related to the desulfurization rate is formulated; according to the calculated value of the desulfurization rate ω, the desulfurizer distribution and addition plan is queried, and the desulfurizer dosage is adjusted by the regulating valve 10 on the corresponding pipeline to control the dosage of each desulfurizer addition position. The desulfurizer distribution and addition plan is specifically shown in Table 1 below. The desulfurizer proportion of the addition position in Table 1 is the ratio of the desulfurizer dosage at the addition position to the total desulfurizer dosage. The desulfurizer distribution and addition plan is specifically: When 0≤ω<20%, ​​the desulfurizer dosage at the first addition position (i.e., the addition position in the left area 2.1) is 0~15% of the total desulfurizer dosage, the desulfurizer dosage at the second addition position (the addition position in the middle area 2.2) is 85%~100% of the total desulfurizer dosage, and the desulfurizer dosage at the third addition position (the addition position in the right area 2.3) is 0; When 20%≤ω<50%, the dosage of desulfurizer at the first dosing position is 15~30% of the total dosage of desulfurizer, the dosage of desulfurizer at the second dosing position is 70%~85% of the total dosage of desulfurizer, and the dosage of desulfurizer at the third dosing position is 0; When 50%≤ω<80%, the dosage of desulfurizer at the first dosing position is 15%~30% of the total dosage of desulfurizer, the dosage of desulfurizer at the second dosing position is 35%~65% of the total dosage of desulfurizer, and the dosage of desulfurizer at the third dosing position is 15%~30% of the total dosage of desulfurizer; When 80%≤ω<99.9%, the desulfurizer dosage at the first addition position is 20~35% of the total desulfurizer dosage, the desulfurizer dosage at the second addition position is 30%~40% of the total desulfurizer dosage, and the desulfurizer dosage at the third addition position is 20~35% of the total desulfurizer dosage.

[0044] Table 1 Desulfurizer distribution and addition plan

[0045] In the present invention, the desulfurizing agent is sodium bicarbonate; the desulfurization reaction is as follows: 2NaHCO 3 →Na 2 CO 3 +H 2 O+CO 2 ; SO 2 +Na 2 CO 3 +O 2 →Na 2 SO 4 +CO 2 .

[0046] In the present invention, the total dosage of the desulfurizing agent M 2 Calculated by the following formula: M 2 =M 1 ×2.76; M 1 =Q 1 ×(C 1 -C 2 ); In the above formula, C 1 For SO 2 The inlet concentration is in mg / Nm 3 ;Q 1 The standard flow rate of CDQ exhaust gas inlet flue gas, in Nm 3 / h; C 2 To meet the control target concentration of emission standards (generally ≤50), the unit is mg / Nm 3 ;M 1 is the SO that needs to be removed from the CDQ exhaust gas per unit time 2 Mass, unit is mg / h.

[0047] In the present invention, due to the SO 2 The concentration fluctuates greatly, and the outlet needs to meet the ultra-low emission environmental protection requirements in real time. The addition and staged use of desulfurizers need to change in real time. 2 The outlet concentration C 3 C 2 The value is dynamically modified when the entry SO 2 Low or high concentrations cause outlet SO 2 Exceeding 5mg / Nm outside the desulfurization control target range 3 By dynamically adjusting the calculation of desulfurization dosage and dosing point, the desulfurizer can be used efficiently, thus reducing the use of desulfurizer. 2 The outlet concentration C 3 C 2 The value is corrected, and the specific correction method is: 1. When C 3 -C 2 ≥5mg / Nm 3 or C 3 -C 2 ≤-5mg / Nm 3 When C 2 The value is corrected to (2C 2 -C 3 ) calculated value; 2. When -5mg / Nm 3 <C 3 -C 2 <5mg / Nm 3 When C 2 The value remains unchanged.

[0048] In the present invention, the real-time desulfurization rate ω can be calculated by the following formula: ω = (C 1 -C 3 )×100% / C 1 .

[0049] Among them, C 3 For SO 2 The outlet concentration is in mg / Nm 3 .

[0050] Embodiment 1 like Figure 1The CDQ vent gas desulfurization system shown comprises a CDQ vent gas inlet pipeline 7, a desulfurizer 2, a dust collector 3, a heat exchanger 4, a booster fan 5 and a chimney 6 which are connected in sequence; the desulfurizer 2 is divided into three connected areas by a guide plate 11, the nozzle in the left area 2.1 sprays upward, so the direction of spraying the desulfurizer is upward, and the vent gas in the left area 2.1 flows from top to bottom; the nozzles in the middle area 2.2 and the right area 2.3 spray downward, which is the same as the flow direction of the CDQ vent gas.

[0051] Embodiment 2 A method for desulfurizing coke dry quenching exhaust gas, using the coke dry quenching exhaust gas desulfurization system described in Example 1 to desulfurize the coke dry quenching exhaust gas of a 140t / h coke quenching furnace. According to the test, the temperature of the coke dry quenching exhaust gas before entering the desulfurizer 2 is 140-160℃, SO 2 The inlet concentration is 380~1200mg / m 3 ; After the CDQ exhaust gas enters the desulfurizer 2, it is sprayed with desulfurizer for desulfurization. The SO in the CDQ exhaust gas is detected in real time. 2 The controller 1 calculates the real-time desulfurization rate, selects a suitable desulfurization agent dosing scheme, and controls the dosage of each dosing point through a regulating valve. The specific desulfurization agent dosing scheme is shown in Table 2.

[0052] Table 2 Desulfurization agent addition scheme in Example 2

[0053] After the system and method of the present invention are put into use, the SO2 emitted by the dry quenching of coke in chimney 6 is measured. 2 The outlet concentration is 15~43mg / Nm 3 , in line with national emission standards. According to calculation, the total dosage of desulfurizer is 180kg / h~420kg / h. By comparison, compared with the original single-point desulfurizer addition technology, the desulfurizer consumption of this embodiment is reduced by 25~35%, and the SO 2 The achievement rate of ultra-low emission concentration increased by 33~37%.

[0054] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0055] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to replace some of the technical features therein with equivalents. However, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A coke dry quenching exhaust gas desulfurization system, characterized in that: It includes a desulfurizer, a dust collector, a booster fan and a chimney which are connected in sequence through pipelines; The inlet of the desulfurizer is connected to the CDQ vent gas inlet pipeline, and the CDQ vent gas inlet pipeline is provided with an inlet SO2 concentration measuring instrument and an inlet flue gas flow detection device; At least one dosing position is arranged in the desulfurizer along the fluid flow direction, and a nozzle for spraying the desulfurizer is arranged on the dosing position, and the nozzle is connected to an external desulfurizer supply pipeline; An outlet SO2 concentration measuring instrument is arranged in the chimney.

2. The CDQ vent gas desulfurization system according to claim 1, characterized in that: The desulfurizer includes a shell having an inlet and an outlet. At least one vertical guide plate is provided in the shell, and the guide plate divides the interior of the shell into a plurality of areas connected in sequence. A dosing position is provided in each area, and the nozzles on each dosing position are respectively connected to the corresponding desulfurizer supply pipeline, and each desulfurizer supply pipeline is separately equipped with a regulating valve.

3. The CDQ exhaust gas desulfurization system according to claim 2, characterized in that: Any two adjacent areas in the shell are connected via a connecting port; and the positions of the two adjacent connecting ports are opposite.

4. The CDQ vent gas desulfurization system according to claim 2 or 3, characterized in that: The shell is divided into three areas from left to right by two vertical guide plates, and a gap is left between the top or bottom of the guide plate and the shell to form a connecting port connecting two adjacent areas; The connecting port between the left area and the middle area is located at the bottom, and the connecting port between the middle area and the right area is located at the top.

5. The CDQ vent gas desulfurization system according to claim 4, characterized in that: In the first area of ​​the desulfurizer along the fluid flow direction, the desulfurizer spraying direction is opposite to the flow direction of the CDQ gas; in other areas, the desulfurizer spraying direction is the same as the flow direction of the CDQ gas.

6. The CDQ vent gas desulfurization system according to claim 5, characterized in that: A heat exchanger is arranged between the dust collector and the booster fan. The outlet of the dust collector is connected to the heat source inlet of the heat exchanger through a pipeline, and the heat source outlet of the heat exchanger is connected to the inlet of the booster fan through a pipeline.

7. The CDQ vent gas desulfurization system according to claim 6, characterized in that: The CDQ vent gas desulfurization system is also provided with a controller, which is respectively connected to each regulating valve, an inlet SO2 concentration measuring instrument, an inlet flue gas flow measuring instrument and an outlet SO2 concentration measuring instrument.

8. A method for desulfurization of coke dry quenching exhaust gas, characterized in that: The method is: Providing the CDQ vent gas desulfurization system according to claim 5; After detecting the inlet flow rate of CDQ vent gas and the inlet concentration of SO2, the CDQ vent gas enters the desulfurizer and is sprayed with desulfurizer. The desulfurizer reacts with SO2 in the CDQ vent gas to desulfurize. The desulfurized CDQ vent gas is dedusted by the dust collector and then enters the heat exchanger to recover waste heat. After the temperature is lowered, it enters the chimney under the action of the booster fan. The outlet concentration of SO2 at the chimney outlet is detected, and the real-time desulfurization rate is calculated based on the inlet flow rate of CDQ vent gas, the inlet concentration of SO2 and the outlet concentration of SO2. The desulfurization agent distribution and addition plan is selected based on the desulfurization rate, and the desulfurizer is added so that the outlet concentration of SO2 in the CDQ vent gas meets the emission standards.

9. The method for desulfurizing the discharged gas from dry coke quenching according to claim 8, characterized in that: The desulfurizer distribution and addition scheme is: When 0≤ω<20%, ​​the dosage of desulfurizer at the first addition position is 0~15% of the total dosage of desulfurizer, the dosage of desulfurizer at the second addition position is 85%~100% of the total dosage of desulfurizer, and the dosage of desulfurizer at the third addition position is 0; When 20%≤ω<50%, the dosage of desulfurizer at the first dosing position is 15~30% of the total dosage of desulfurizer, the dosage of desulfurizer at the second dosing position is 70%~85% of the total dosage of desulfurizer, and the dosage of desulfurizer at the third dosing position is 0; When 50%≤ω<80%, the dosage of desulfurizer at the first dosing position is 15%~30% of the total dosage of desulfurizer, the dosage of desulfurizer at the second dosing position is 35%~65% of the total dosage of desulfurizer, and the dosage of desulfurizer at the third dosing position is 15%~30% of the total dosage of desulfurizer; When 80%≤ω<99.9%, the desulfurizer dosage at the first addition position is 20~35% of the total desulfurizer dosage, the desulfurizer dosage at the second addition position is 30%~40% of the total desulfurizer dosage, and the desulfurizer dosage at the third addition position is 20~35% of the total desulfurizer dosage.

10. The method for desulfurizing the discharged gas from dry coke quenching according to claim 9, characterized in that: The real-time desulfurization rate ω is calculated by the following formula: ω = (C1-C3) × 100% / C1; The total dosage of desulfurizer M2 is calculated by the following formula: M2=M1×2.76; M1=Q1×(C1-C2); In the above formula, C1 is the inlet concentration of SO2, in mg / Nm 3 ; Q1 is the standard flow rate of CDQ exhaust gas inlet, in Nm 3 / h; C2 is the control target concentration that meets the emission standards, in mg / Nm 3 ; M1 is the mass of SO2 that needs to be removed from the CDQ exhaust gas per unit time, in mg / h; C3 is the outlet concentration of SO2, in mg / Nm 3 .

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