Method for preventing corrosion of bag type dust collector under high-humidity working condition of dry and wet quenching dust collection

Abstract

The invention provides a method for preventing a bag type dust collector from being corroded under the high-humidity working condition of dry and wet coke quenching dust removal, and belongs to the technical field of coke quenching dust removal. A dust removal system, an air return system, a calcium oxide treatment system and a humidity sensor are included; the dust removal system comprises a bag type dust remover, a dust removal fan and an exhaust funnel, and the bag type dust remover, the dust removal fan and the exhaust funnel are communicated in sequence; the air return system comprises an air return pipeline, an air return fan, a first electric control valve and a nozzle; the calcium oxide treatment system comprises a calcium oxide bin, a Roots blower, a calcium oxide conveying pipeline, a calcium oxide conveying bypass pipeline and a second electric control valve; according to the system, the air return system and the calcium oxide treatment system are additionally arranged, distribution of airflow in the corner area of the ash bin is improved, the dew point temperature of the local environment is increased by means of the moisture absorption and heat release characteristics of calcium oxide, and therefore the problem that the corners of the ash bin are dewed and corroded is fundamentally solved, and the service life is prolonged.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of coke quenching and dust removal, and particularly relates to a method for preventing corrosion of a bag-type dust collector under high-humidity working conditions of dry-wet coke quenching and dust removal. BACKGROUND

[0002] The state has further improved the control requirements for flue gas emission. In order to meet the increasingly stringent emission requirements, in recent years, coke enterprises across the country have implemented large-scale flue gas purification system modification projects, and generally added high-efficiency dust removal systems.

[0003] However, in the actual operation process of the system, it is found that when the bag-type dust collector processes flue gas of a wet coke quenching system or a dry-wet coke quenching mixed system, since a large amount of water vapor is contained in such flue gas, when the outdoor temperature suddenly drops below the dew point in winter or in cold regions, water vapor is easily condensed and liquid water is precipitated in the vortex area such as the corner of the dust collector ash bin and the dead angle of flue gas flow. The liquid water reacts with the acidic gas in the flue gas, thereby corroding the bag-type dust collector, so that the service life of the bag-type dust collector can only be maintained for 1-2 years, which seriously affects the production continuity and greatly increases the maintenance cost.

[0004] Therefore, how to solve the problem of easy corrosion in the corner area of the dust collector ash bin when the wet coke quenching system or the dry-wet coke quenching shared dust removal system is used in coking production is crucial. SUMMARY

[0005] Based on the above technical problems, the purpose of the application is to provide a method for preventing corrosion of a bag-type dust collector under high-humidity working conditions of dry-wet coke quenching and dust removal. The system improves the distribution of air flow in the corner area of the ash bin by adding a return air system and a calcium oxide treatment system, and uses the moisture absorption and heat release characteristics of calcium oxide to raise the dew point temperature of the local environment, thereby fundamentally solving the problem of condensation corrosion in the corner area of the ash bin, and prolonging the service life.

[0006] The specific technical scheme is as follows: A method for preventing bag dust collector corrosion under high humidity conditions of dry and wet coke quenching dust removal, comprising: a dust removal system, a return air system, a calcium oxide treatment system and a humidity sensor; the dust removal system comprises a bag dust collector, a dust removal fan and an exhaust pipe, and the bag dust collector, the dust removal fan and the exhaust pipe are connected in sequence; the return air system comprises a return air duct, a return air fan, a first electric regulating valve and a nozzle, and by utilizing the positive pressure effect of the original dust removal fan and the negative pressure effect of the return air fan, a portion of the flue gas in the positive pressure section of the dust removal fan is extracted and sent to the nozzle, and then sprayed towards the corner of the ash bin of the bag dust collector, thereby improving the airflow distribution in the corner of the ash bin and preventing the generation of vortexes; the calcium oxide treatment system It includes a calcium oxide silo, a Roots blower, a calcium oxide conveying pipe, a calcium oxide conveying bypass pipe and a second electric regulating valve. The Roots blower is used to deliver powdered calcium oxide to the return air duct, and then the calcium oxide powder is delivered to the nozzle through the positive pressure of the return air blower, and reacts with the water vapor in the high-humidity flue gas at the vortex in the corner of the ash silo, thereby reducing the relative humidity of the flue gas. A large amount of heat is released during the reaction between calcium oxide and water, and the heat generated by the reaction can increase the local temperature at the corner of the bag dust collector; the humidity sensor is arranged on one side of the bag dust collector, and the opening and closing of the first electric regulating valve and the second electric regulating valve are controlled according to the humidity value detected by the humidity sensor.

[0007] In addition, the method for preventing bag filter corrosion under high humidity conditions of dry and wet coke quenching dust removal in the above technical solution provided by the present invention may also have the following additional technical features: In the above technical solution, a gate valve is provided on the return air duct, and the gate valve is located in front of the return air fan.

[0008] In the above technical solution, the sensor is interlocked with the first electric regulating valve and the second electric regulating valve.

[0009] In the above technical solution, a silo pump is provided at the ash discharge port of the ash silo at the bottom of the bag dust collector. The input end of the silo pump is connected to the first compressed air storage tank, the output end of the silo pump is connected to the pneumatic conveying pipe, and the pneumatic conveying pipe is connected to the dust storage silo.

[0010] In the above technical solution, a humidifier is provided at the bottom of the dust storage bin.

[0011] In the above technical solution, the nozzle is arranged on the side wall of the bag filter and is opposite to the corner position of the ash bin.

[0012] The above technical solution also includes: a second compressed air storage tank, which is connected to the bag dust collector and is used for blowing the bags in the bag dust collector.

[0013] In the above technical solution, the control method of the first electric regulating valve and the second electric regulating valve includes: Working condition a: when the humidity sensor at the corner of the bag type dust collector ash bin measures that the relative humidity of flue gas is less than 70%, the first electric regulating valve ensures a minimum opening of 50%, and the second electric valve is in a closed state, for improving the air flow organization at the corner of the bin; Working condition b: when the humidity sensor at the corner of the bag type dust collector ash bin measures that the relative humidity of flue gas reaches 70%, the opening of the first electric regulating valve and the second electric regulating valve is adjusted to 70%; Working condition c: when the humidity sensor at the corner of the bag type dust collector ash bin measures that the relative humidity of flue gas reaches 85%, the opening of the first electric regulating valve and the second electric regulating valve is adjusted to 85%; Working condition d: when the humidity sensor at the corner of the bag type dust collector ash bin measures that the relative humidity of flue gas reaches 95%, the opening of the first electric regulating valve and the second electric regulating valve is adjusted to 100%; In order to avoid frequent switching between working conditions, when the corresponding conditions continuously meet the new working condition for 20s, the working condition is switched.

[0014] Compared with the prior art, the method for preventing corrosion of a bag type dust collector under high humidity working condition of dry and wet coke quenching and dust removal has the beneficial effects that: 1. By utilizing the positive pressure of the original dust removal fan, combining with the added return air system, circulating part of the gas in the connecting pipeline between the dust removal fan and the exhaust cylinder back to the bag type dust collector, the air flow distribution at the corner of the ash bin is optimized, the influence of dew condensation corrosion on the corner of the ash bin is reduced, and by adding a calcium oxide treatment system, the dew point temperature of the local environment is improved by utilizing the moisture absorption and heat release characteristics of calcium oxide, thereby fundamentally solving the problem of dew condensation corrosion at the corner of the ash bin, and prolonging the service life.

[0015] 2. The humidity sensor monitors the humidity at the corner of the bin in real time, and the first electric regulating valve and the second electric regulating valve are linked, so that the system can adjust the return air quantity and the calcium oxide conveying quantity according to the measured different humidity values.

[0016] 3. By adding a plug-in valve in front of the return air fan, the return air fan can be easily maintained. BRIEF DESCRIPTION OF DRAWINGS

[0017] Fig. 1 The flow chart of the method for preventing corrosion of a bag type dust collector under high humidity working condition of dry and wet coke quenching and dust removal; Fig. 2 The top view of the bag type dust collector; Fig. 3 The control principle diagram of the electric regulating valve; Among them, Figs. 1-2 The corresponding relationship between the reference signs and the component names in the drawings is as follows: 10. Bag dust collector, 11. Dust removal fan, 12. Exhaust pipe, 13. Return air duct, 14. Return air fan, 15. First electric regulating valve, 16. Nozzle, 17. Calcium oxide silo, 18. Roots blower, 19. Calcium oxide conveying pipeline, 20. Calcium oxide conveying bypass pipeline, 21. Second electric regulating valve, 22. Humidity sensor, 23. Gate valve, 24. Silo pump, 25. First compressed air storage tank, 26. Pneumatic conveying pipeline, 27. Dust storage silo, 28. Humidifier, 29. Second compressed air storage tank. DETAILED DESCRIPTION

[0018] The following is a combination of specific implementation cases and attached Figs. 1-3 The present invention is further described below, but the present invention is not limited to these embodiments.

[0019] A method for preventing bag filter corrosion under high humidity conditions of dry and wet coke quenching dust removal, such as Figs. 1-3 As shown, it includes: a dust removal system, a return air system, a calcium oxide treatment system and a humidity sensor 22; the dust removal system includes a bag dust collector 10, a dust removal fan 11 and an exhaust pipe 12, and the bag dust collector 10, the dust removal fan 11 and the exhaust pipe 12 are connected in sequence; the return air system includes a return air duct 13, a return air fan 14, a first electric regulating valve 15 and a nozzle 16, one end of the return air duct 13 is connected to the connecting pipe between the dust removal fan 11 and the exhaust pipe 12, and the other end of the return air duct 13 is connected to the ash bin of the bag dust collector 10 through the nozzle 16, and the return air fan 14 and the first electric regulating valve 15 are both arranged on the return air duct 13; the calcium oxide treatment system includes a calcium oxide treatment system A calcium silo 17, a Roots blower 18, a calcium oxide conveying pipe 19, a calcium oxide conveying bypass pipe 20 and a second electric regulating valve 21. The calcium oxide conveying pipe 19 is respectively connected to the calcium oxide silo 17 and the desulfurization flue gas pipe of the plant desulfurization system, and the Roots blower 18 is connected to the calcium oxide conveying pipe 19; the two ends of the calcium oxide conveying bypass pipe 20 are respectively connected to the calcium oxide conveying pipe 19 and the return air pipe 13, and the second electric regulating valve 21 is arranged on the calcium oxide conveying bypass pipe 20; the humidity sensor 22 is arranged in the bag dust collector 10, and the opening and closing of the first electric regulating valve 15 and the second electric regulating valve 21 are controlled according to the humidity value detected by the humidity sensor 22.

[0020] The above structure utilizes the positive pressure of the existing dust removal fan 10 and combines it with the added return air system. The negative pressure of the return air fan 14 is used to extract a portion of the flue gas from the positive pressure section of the dust removal fan 11 and send it to the nozzle 16. The flue gas is then sprayed toward the corners of the ash bin of the bag filter 10, thereby improving the airflow distribution in the corners of the ash bin and reducing the impact of condensation corrosion on the corners of the ash bin. The powdered calcium oxide is delivered to the return air duct 13 by using the Roots blower 18, and then delivered to the nozzle 16 by the positive pressure of the return air fan 14, and reacts with the water vapor in the high-humidity flue gas at the vortex in the corner of the ash bin, thereby reducing the relative humidity of the flue gas. A large amount of heat is released during the reaction between calcium oxide and water. The heat generated by the reaction can increase the local temperature at the corner of the bag dust collector 10, thereby fundamentally solving the problem of condensation corrosion in the corner of the ash bin and extending its service life.

[0021] Specifically, the calcium oxide powder is directly mixed with the gas in the return air duct 13 after the first electric regulating valve 15. Compared with mixing before the nozzle 16, the lift of the Roots blower 18 can be reduced, and the calcium oxide powder reacts with the water vapor in the return air duct 13 to increase the temperature of the return air, which is more conducive to solving the problem of corrosion in the corners of the ash bin of the bag dust collector 10.

[0022] Specifically, the airflow distribution in the corner area of ​​the ash bin of the bag dust collector 10 is optimized by utilizing the return air of the positive pressure section of the dust removal fan 11. At the same time, the water vapor in the corner area of ​​the ash bin is processed by the original calcium oxide silo 17 of the environmental dust removal ground station, thereby making full use of the resources of the existing equipment in the system. There is no need to build new silos and flue gas treatment equipment, and the secondary utilization of dust removal flue gas is achieved.

[0023] Specifically, the calcium oxide treatment system is also equipped with a muffler and a rotary feeder. Specifically, compressed air can be introduced from a nearby air source to assist in blowing the calcium oxide delivery pipeline 19 , thereby preventing the calcium oxide delivery pipeline 19 from being blocked.

[0024] In the embodiment of the present invention, a gate valve 23 is provided on the return air duct 13 , and the gate valve 23 is located before the return air fan 14 .

[0025] By adding a gate valve 23 in front of the return air fan 14, it is convenient to inspect and repair the return air fan 14.

[0026] In the embodiment of the present invention, the sensor is interlocked with the first electric regulating valve 15 and the second electric regulating valve 21 .

[0027] The humidity sensor 22 monitors the humidity in the warehouse corner in real time, and links the first electric regulating valve 15 and the second electric regulating valve 21, so that the system can adjust the return air volume and the calcium oxide delivery volume according to the different humidity values ​​measured.

[0028] In an embodiment of the present invention, a silo pump 24 is provided at the ash discharge port of the ash silo at the bottom of the bag dust collector 10, the input end of the silo pump 24 is connected to the first compressed air storage tank 25, the output end of the silo pump 24 is connected to the pneumatic conveying pipe 26, and the pneumatic conveying pipe 26 is connected to the dust storage silo 27.

[0029] The calcium hydroxide generated by the reaction of calcium oxide and water in the bag type dust collector 10 can directly react with sulfur dioxide in the flue gas, and the generated calcium sulfate and calcium sulfite are transported to the dust storage bin 27 by the bin pump 24.

[0030] In the embodiment of the present application, the dust storage bin 27 is provided with a humidifier 28 at the bottom.

[0031] The dust discharged from the dust storage bin 27 is subjected to humidification treatment by the humidifier 28.

[0032] In the embodiment of the present application, the nozzle 16 is arranged on the side wall of the bag type dust collector 10 and opposite to the corner position of the ash bin.

[0033] In the embodiment of the present application, a second compressed air storage tank 29 is further included, which is connected to the bag type dust collector 10 and used for blowing operation on the cloth bag in the bag type dust collector 10.

[0034] The compressed air in the second compressed air storage tank 29 is blown on the cloth bag, so as to achieve the purpose of regularly cleaning the cloth bag and avoiding blockage caused by excessive dust accumulation on the surface of the cloth bag.

[0035] In the embodiment of the present application, the control mode of the first electric regulating valve 15 and the second electric regulating valve 21 includes: Working condition a: when the relative humidity of the flue gas measured by the humidity sensor 22 at the corner of the ash bin of the bag type dust collector 10 is lower than 70%, the first electric regulating valve 15 ensures a minimum opening degree of 50%, and the second electric valve is in a closed state, so as to improve the air flow organization at the corner of the bin; Working condition b: when the relative humidity of the flue gas measured by the humidity sensor 22 at the corner of the ash bin of the bag type dust collector 10 reaches 70%, the opening degrees of the first electric regulating valve 15 and the second electric regulating valve 21 are adjusted to 70%; Working condition c: when the relative humidity of the flue gas measured by the humidity sensor 22 at the corner of the ash bin of the bag type dust collector 10 reaches 85%, the opening degrees of the first electric regulating valve 15 and the second electric regulating valve 21 are adjusted to 85%; Working condition d: when the relative humidity of the flue gas measured by the humidity sensor 22 at the corner of the ash bin of the bag type dust collector 10 reaches 95%, the opening degrees of the first electric regulating valve 15 and the second electric regulating valve 21 are adjusted to 100%; In order to avoid frequent switching between working conditions, when the corresponding conditions continuously meet the new working condition for 20s delay, the working condition is switched.

[0036] In the description of the application, the term "a plurality of" refers to two or more, unless otherwise expressly specified, and the terms "upper", "lower", and the like, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the application and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application; the terms "connected", "mounted", "fixed" and the like should be understood broadly, for example, "connected" can be fixed connection, can also be detachable connection, or integral connection; can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0037] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preventing corrosion of a bag-type dust collector under high humidity conditions in a dry quenching and wet quenching dust removal system, characterized in that, The utility model relates to a dust removal system, a return air system, a calcium oxide treatment system and a humidity sensor. The dust removal system comprises a bag filter, a dust removal fan and an exhaust cylinder, which are sequentially communicated. The return air system comprises a return air pipeline, a return air fan, a first electric regulating valve and a nozzle. The calcium oxide treatment system comprises a calcium oxide bin, a Roots fan, a calcium oxide conveying pipeline, a calcium oxide conveying bypass pipeline and a second electric regulating valve. The humidity sensor is arranged on one side of the bag filter.

2. The method for preventing the corrosion of a bag-type dust collector in a high-humidity working condition under dry-wet quenching and dust removal according to claim 1, characterized in that, The return air pipeline is provided with a plug valve, which is located in front of the return air fan.

3. The method according to claim 1, wherein the method is characterized by, The sensor is interlocked with the first electric regulating valve and the second electric regulating valve.

4. The method for preventing the corrosion of a bag-type dust collector in a high-humidity condition under a dry-wet quenching and dust removal process according to claim 1, characterized in that, The dust bin of the bag filter is provided with a bin pump, the input end of which is connected with a first compressed air tank, and the output end of which is connected with a pneumatic conveying pipeline, which is connected with a dust storage bin.

5. The method for preventing the corrosion of a bag-type dust collector in a high-humidity condition under a dry-wet quenching and dust removal process according to claim 4, characterized in that, The dust storage bin is provided with a humidifier at the bottom.

6. The method for preventing the corrosion of a bag-type dust collector in a high-humidity condition under a dry-wet quenching and dust removal process according to claim 1, characterized in that, The nozzle is arranged on the side wall of the bag filter and is opposite to the corner of the dust bin.

7. The method according to claim 1, wherein the method is characterized by, The utility model further comprises a second compressed air tank, which is connected with the bag filter and is used for spraying and blowing the bag of the bag filter. The control mode of the first electric regulating valve and the second electric regulating valve comprises:

8. The method according to claim 3, wherein the method is characterized by, When the humidity sensor at the corner of the dust bin of the bag filter measures that the relative humidity of the flue gas is lower than 70%, the first electric regulating valve ensures a minimum opening of 50%, and the second electric valve is in a closed state, so as to improve the air distribution at the corner of the dust bin. When the humidity sensor at the corner of the dust bin of the bag filter measures that the relative humidity of the flue gas reaches 70%, the opening of the first electric regulating valve and the second electric regulating valve is adjusted to 70%. When the humidity sensor at the corner of the dust bin of the bag filter measures that the relative humidity of the flue gas reaches 85%, the opening of the first electric regulating valve and the second electric regulating valve is adjusted to 85%. When the humidity sensor at the corner of the dust bin of the bag filter measures that the relative humidity of the flue gas reaches 95%, the opening of the first electric regulating valve and the second electric regulating valve is adjusted to 100%. In order to avoid frequent switching between working conditions, when the corresponding conditions continuously meet the new working condition for 20s, the working condition is switched. ​

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