System and method for pretreating VOCs (volatile organic compounds) tail gas from coke discharged from carbonization furnace

Abstract

The invention belongs to the field of VOCs tail gas treatment in the semi-coke industry, and relates to a pretreatment system and method for VOCs tail gas generated in coke discharged from a carbonization furnace. Suction force is formed through the upper bridge type bent pipe and the first spray head, VOCs tail gas containing wet dust and escaping during coke discharging of the carbonization furnace is sucked in, superheated water vapor in the VOCs tail gas is saturated and cooled, the temperature of the VOCs tail gas is reduced to 70 DEG C or below, then dust removal and cooling are further conducted through the lower bridge type bent pipe, the second spray head and the third spray head, and the VOCs tail gas is discharged from the carbonization furnace. The temperature of the VOCs tail gas is reduced to 55 DEG C or below, and the VOCs tail gas is demisted and dried through the detachable baffle plate and the detachable filler and finally pumped to a next treatment facility through the diagonal flow type pipeline fan. The problem that in the VOCs tail gas suction and collection process, a large amount of air is sucked, and consequently the waste gas treatment amount is too large is solved, and the problems that before the VOCs tail gas is sent to a washing tower, the temperature and the moisture content are high, the treatment effect is poor, and components such as wet dust and tar are prone to settling and adhering to the inner wall of a pipeline, and cleaning is difficult are effectively solved.

Description

Technical Field

[0001] The invention belongs to the field of VOCs tail gas treatment in the semi-coke industry, and specifically relates to a system and method for pretreating VOCs tail gas from coke outlet of a carbonization furnace. Background Art

[0002] Semi-coke, also known as semi-coke, is a solid carbon product obtained by dry distillation of low-rank coal such as long flame coal and weakly sticky coal under medium and low temperature conditions. In the production process of semi-coke, when the coke is discharged from the bottom of the carbonization furnace, a large amount of waste gas (mainly composed of water vapor, dust, VOCs, tar, ammonia, a small amount of coal gas, etc.) is generated by quenching the coke at the bottom of the furnace. When the plug valve of the coke discharge bin is opened, it escapes into the corridor of the coke discharge belt pit, forming waste gas containing VOCs (Volatile Organic Compounds).

[0003] The traditional treatment method is to collect this part of the exhaust gas through the suction hood, suck it with the fan, and then send it to the subsequent VOCs tail gas treatment device for treatment. Since the instantaneous volume of tail gas is very large, in the process of exhaust gas suction, in order to prevent the tail gas from escaping, it is necessary to form a large negative pressure at the suction end, causing a large amount of air to be sucked in, making the subsequent equipment handle too much gas, which not only causes high investment costs for subsequent supporting towers, pumps, pipelines, etc., but also high power consumption of pumps, high operation and maintenance costs, which runs counter to the industry direction of energy saving and consumption reduction.

[0004] In addition, the pipeline for transporting exhaust gas to the VOCs exhaust gas treatment device (usually composed of a washing tower, a demisting drying tower, an adsorption tower, etc.) is long. A large amount of water vapor, dust, tar, etc. in the exhaust gas condenses, settles, and forms agglomerates in the pipeline, resulting in serious scaling of the pipeline that is difficult to clean. As a result, the VOCs treatment facility is shut down for maintenance after being operated for a period of time, which is also contrary to the industry's direction of clean, environmentally friendly, and ultra-low emissions. Summary of the invention

[0005] The object of the present invention is to provide a system and method for pretreating VOCs tail gas from coke output from a carbonization furnace to overcome the above-mentioned technical defects.

[0006] In order to solve the above technical problems, the present invention provides a carbonization furnace coke outlet VOCs tail gas pretreatment system, which is arranged downstream of the coke outlet bin gate valve of the carbonization furnace, and along the conveying direction of the VOCs tail gas, comprises a first pipeline, an upper bridge elbow, a lower bridge elbow and a second pipeline which are sequentially sealed and connected; An air suction hood is sealed and installed at the inlet end of the first pipeline; An oblique flow duct fan is installed at the outlet end of the second duct; Wherein, a plurality of nozzles are installed in the pipes of the upper bridge elbow and the second pipe, and the nozzles are interlocked with the coke outlet bin gate valve to control the air intake amount entering the suction hood.

[0007] According to a carbonization furnace coke VOCs tail gas pretreatment system, the upper bridge type elbow is an inverted V-shaped structure consisting of a first left inclined pipe and a first right inclined pipe, and a first nozzle is installed in the first right inclined pipe; The first nozzle adopts a pressure regulating nozzle to control the suction force.

[0008] According to a carbonization furnace coke VOCs tail gas pretreatment system, the upper bridge type elbow pipe is lined with wear-resistant ceramic sheets; The junction of the first left oblique tube and the first right oblique tube vertically extends upward to form a first straight tube; A first glass sight glass is installed in the first straight tube.

[0009] According to a carbonization furnace coke VOCs tail gas pretreatment system, the lower bridge elbow is a positive V-shaped structure consisting of a second left inclined pipe and a second right inclined pipe; The junction of the second left oblique tube and the second right oblique tube vertically extends downward to form a second straight tube; A liquid level sensor is arranged in the second straight pipe; The outlet of the second straight pipe is connected to a drainage pipe, and the drainage pipe leads to a circulating water tank; An electric drain valve is installed on the drain pipe; The liquid level sensor and the electric drain valve operate in an interlocking manner.

[0010] According to a carbonization furnace coke-out VOCs tail gas pretreatment system, along the conveying direction of the VOCs tail gas, a second nozzle, a detachable baffle, a detachable filler, and a third nozzle are sequentially installed in the second pipeline.

[0011] According to a carbonization furnace coke VOCs tail gas pretreatment system, a temperature sensor, a pressure sensor, and a second glass sight glass are arranged on the inner wall of the pipe between the detachable filler and the third nozzle; Wherein, the pressure sensor operates in interlock with the diagonal flow duct fan.

[0012] According to a carbonization furnace coke-out VOCs tail gas pretreatment system, a strip of polyurethane tape is bonded to the inlet end of the air intake hood.

[0013] The present invention also provides a method for pretreating VOCs tail gas from coking in a carbonization furnace, which uses a system for pretreating VOCs tail gas from coking in a carbonization furnace, comprising: The coke outlet gate valve is opened, the first nozzle is interlocked and opened, a negative pressure is formed at the suction hood to suck the VOCs tail gas into the upper bridge elbow, and the high-pressure jet generated by the first nozzle washes the VOCs tail gas and cools it down to below the temperature T1; The VOCs tail gas moves forward into the lower bridge elbow and is condensed into droplets; The second nozzle is started to wash, condense and cool the VOCs tail gas to a temperature below T2, the VOCs tail gas carries droplets and contacts the detachable baffle, the detachable baffle captures the droplets, the VOCs tail gas continues to move forward and contacts the detachable filler, and the detachable filler demists the VOCs tail gas; The pressure sensor detects the pressure. If the pressure is higher than P 设定 When the VOCs exhaust gas is discharged, the diagonal flow duct fan is interlocked and started, and the diagonal flow duct fan sucks the VOCs exhaust gas and transports the VOCs exhaust gas to the downstream.

[0014] According to a method for pre-treating VOCs tail gas from coke-out of a carbonization furnace, when the VOCs tail gas carries droplets and contacts the detachable baffle, the detachable baffle captures the droplets, and the droplets flow downward and are collected in the second straight pipe of the lower bridge elbow. The liquid level sensor in the second straight pipe detects the liquid level. If the liquid level reaches an ultra-high liquid level HH, the electric drain valve is interlocked to discharge the accumulated liquid. If the liquid level reaches an ultra-low liquid level LL, the electric drain valve is interlocked to close. After the detachable filler in step demists the VOCs tail gas, the wet dust content of the VOCs tail gas in the second pipe is observed through the second glass sight glass to start the third nozzle to supplement the washing of the VOCs tail gas.

[0015] According to a method for pretreating VOCs tail gas from coke outlet of a carbonization furnace, when the coke outlet bin gate valve is in a closed state, the spray pressure value of the first nozzle is lowered, the timing is set for M minutes, and then the first nozzle is closed, and at the same time, the diagonal flow duct fan is closed to stop the VOCs tail gas transportation.

[0016] The present invention forms a suction force through the upper bridge-type elbow and the first nozzle, sucks in the VOCs tail gas containing wet dust that escapes when the carbonization furnace is discharged from the coke, and saturates and cools the superheated water vapor in the VOCs tail gas, so that the temperature of the VOCs tail gas is reduced to below 70°C, and then further removes dust and cools the temperature through the lower bridge-type elbow and the second and third nozzles, so that the temperature of the VOCs tail gas is reduced to below 55°C, and then defogs and dries through a detachable baffle and a detachable filler, and finally pumps it to the next treatment facility through an oblique flow duct fan. This method not only solves the problem that a large amount of air is sucked in during the VOCs tail gas suction and collection process, thereby resulting in excessive waste gas treatment volume, but also effectively solves the problems that before the VOCs tail gas is sent to the washing tower, the temperature and moisture content are high, resulting in poor treatment effect, and components such as wet dust and tar are easy to settle and adhere to the inner wall of the pipeline, making cleaning difficult, and the like.

[0017] In order to make the above contents of the present invention more clearly understood, preferred embodiments are given below and described in detail in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the VOCs tail gas pretreatment system of the carbonization furnace.

[0019] Description of reference numerals: 10. Suction hood; 20. First pipeline; 30. Upper bridge elbow; 31. First nozzle; 32. First straight pipe; 40. Lower bridge elbow; 41. Second straight pipe; 50. Second pipeline; 51. Electric drain valve; 52. Second nozzle; 53. Removable baffle; 54. Removable filler; 55. Third nozzle; 60. Diagonal flow duct fan; 70. Coke outlet gate valve. DETAILED DESCRIPTION

[0020] The following describes the implementation of the present invention through specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0021] It should be noted that, in the present invention, the top, bottom, left and right in the figure are deemed as the top, bottom, left and right of the carbonization furnace coke VOCs tail gas pretreatment system described in this specification.

[0022] The exemplary embodiments of the present invention are now described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0023] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0024] This embodiment relates to a VOCs tail gas pretreatment system for coking out of a carbonization furnace, such as Figure 1 As shown, it is arranged downstream of the coke discharge bin gate valve 70 of the carbonization furnace. The coke discharge bin gate valve 70 is arranged at the discharge port and the upper part of the chute of the coke discharge belt of the carbonization furnace. The discharge port and the chute are directly connected to the coke discharge belt, that is, when the coke discharge bin gate valve 70 is opened, the lignite falls into the coke discharge belt, and the VOCs exhaust gas discharged therefrom quickly escapes into the closed material guide trough of the coke discharge belt.

[0025] See also Figure 1 Along the conveying direction of VOCs tail gas, the carbonization furnace coke VOCs tail gas pretreatment system includes a first pipeline 20, an upper bridge elbow 30, a lower bridge elbow 40 and a second pipeline 50 which are sealed and connected in sequence, forming a through pipeline passage.

[0026] An air suction hood 10 is sealed and installed at the inlet end of the first pipeline 20, and the air suction hood 10 is used to inhale VOCs tail gas.

[0027] In some embodiments, see Figure 1 The first pipeline 20 can be a metal hose, the lower end of the metal hose is sealed and connected to the air intake hood 10 through a flange, and the upper end of the metal hose is sealed and connected to the upper bridge elbow 30 through a flange.

[0028] In some embodiments, the air hood 10 adopts a round and square metal structure, and a strip of polyurethane tape is bonded to the inlet end of the air hood 10, and a gap of 20 to 30 mm is left between each strip of polyurethane tape. The VOCs tail gas pretreatment system of the carbonization furnace runs on a belt conveyor. The role of the strip of polyurethane tape is to facilitate the material transportation of the belt conveyor when the VOCs tail gas is sucked. The tape is mainly made of the excess belt of the belt conveyor, and the belt material is mostly polyurethane, so the strip of polyurethane tape is selected.

[0029] It should be noted that the inlet end of the air hood 10 can also be bonded with a tape piece made of other materials.

[0030] Please continue reading Figure 1 The outlet end of the second pipeline 50 is equipped with a diagonal flow pipeline fan 60, which can suck the treated VOCs tail gas and transport the treated VOCs tail gas to a subsequent treatment process.

[0031] A plurality of nozzles are installed in the upper bridge elbow 30 and the second pipeline 50 , and the nozzles are interlocked with the coke outlet gate valve 70 to control the amount of air sucked into the suction hood 10 .

[0032] In some embodiments, see Figure 1 The upper bridge elbow 30 is an inverted V-shaped structure composed of a first left oblique tube and a first right oblique tube. A first nozzle 31 is installed in the first right oblique tube. The first nozzle 31 adopts a pressure regulating nozzle to control the suction force.

[0033] like Figure 1 As shown, the angle between the central axis of the first nozzle 31 and the central axis of the first right inclined tube is 0° to 10°, that is, the injection direction is basically consistent with the VOCs exhaust gas transportation direction, and deviation is allowed within the range of 0° to 10°.

[0034] Specifically, the first nozzle 31 adopts a pressure regulating nozzle, the pressure regulating range is 1.5-3.5 MPa, and the spraying angle is 30-135°.

[0035] The upper bridge type elbow 30 has an included angle of 45° to 135°, and the pipe is lined with wear-resistant ceramic sheets. Since there is a lot of dust in the upper bridge type elbow 30, the dust easily causes wear to the pipe wall. Considering the wear resistance of the pipe wall, wear-resistant ceramic sheets are selected to be lined in the pipe.

[0036] The junction of the first left oblique tube and the first right oblique tube of the upper bridge type bent pipe 30 extends vertically upward to form a first straight tube 32. A first glass endoscope is installed in the first straight tube 32. The function of the first glass endoscope is to facilitate the setting of a camera. The image in the pipeline is transmitted to the central control monitoring screen through the first glass endoscope to judge in real time whether the pipeline is seriously blocked or not.

[0037] It should be particularly noted that the first nozzle 31 is interlocked with the coke outlet gate valve 70. Specifically, when the coke outlet gate valve 70 is opened, the first nozzle 31 is interlocked to open, so that the pressure is at a high value, forming a high-pressure jet effect, forming a suction force, and quickly sucking the VOCs exhaust gas into the upper bridge elbow 30. When the coke outlet gate valve 70 is closed, the pressure of the first nozzle 31 is adjusted to a low value to reduce the suction force, and a timer is set. When the time reaches the set value, the exhaust gas collection system is automatically closed, thereby reducing the amount of air intake, and ultimately reducing the amount of exhaust gas treatment, reducing the investment and operating costs of subsequent treatment facilities.

[0038] Please continue reading Figure 1 The lower bridge elbow 40 is a regular V-shaped structure consisting of a second left oblique tube and a second right oblique tube. The junction of the second left oblique tube and the second right oblique tube extends vertically downward to form a second straight tube 41. A liquid level sensor is arranged in the second straight tube 41. The outlet of the second straight tube 41 is connected to a drainage pipe, and the drainage pipe leads to a circulating water tank. An electric drainage valve 51 is installed in the drainage pipe. The liquid level sensor and the electric drainage valve 51 are interlocked for operation.

[0039] That is, when the liquid level reaches a certain value, the liquid level sensor is triggered, and the electric drain valve 51 is interlocked to open. Specifically, the liquid level sensor transmits liquid level data to the central control DCS (Distributed Control System), and the central control DCS sets an interlocking measure to open or close the electric drain valve 51.

[0040] In some embodiments, a guide blade with three lines and four channels (i.e., the channel part of the blade is formed by three main line plates to form four channels) is provided at the elbow of the second left inclined tube and the second right inclined tube connected to the second straight tube 41. The guide blade can guide the conveying direction of the VOCs exhaust gas and comb the airflow.

[0041] The bend angle of the lower bridge elbow 40 is 45° to 135°. Since the inner wall of the lower bridge elbow 40 is in contact with the spray water for a long time, the inner wall of the pipe is easily corroded and damaged by the spray water. Therefore, the pipeline is lined with anti-corrosion and wear-resistant materials.

[0042] The first right oblique tube of the upper bridge type elbow 30 and the second left oblique tube of the lower bridge type elbow 40 are seal-welded.

[0043] Please continue reading Figure 1 Along the conveying direction of the VOCs tail gas, a second nozzle 52, a detachable baffle 53, a detachable filler 54, and a third nozzle 55 are installed in sequence in the second pipeline 50.

[0044] The central axis of the second nozzle 52 is installed at an angle of 30° to the central axis of the second pipe 50, and the second nozzle 52 adopts a low-pressure nozzle with a pressure of 0.3~0.6MPa and a spray angle of 60~75°; the third nozzle 55 adopts a low-pressure nozzle with a pressure of 0.7MPa.

[0045] Since washing nozzles are arranged in both the upper bridge elbow 30 and the second pipe 50, a large amount of water vapor and dust in the VOCs tail gas can be quickly removed in advance by spraying water mist for washing, cooling and dust removal, which effectively solves the problem of wet dust, tar, etc. settling and sticking into blocks in the pipe during the subsequent transportation of the VOCs tail gas, causing serious scaling and clogging.

[0046] In some embodiments, the baffles of the detachable baffles 53 are double-arcuate, with a total height of 250-300 mm and a baffle spacing of 25-45 mm. The packing height of the detachable packing 54 is 400-600 mm.

[0047] Since the removable baffle 53 and the removable filler 54 are arranged in the second pipe 50, the water mist after washing can be removed by inertial capture, which effectively reduces the water vapor content in the VOCs exhaust gas and creates good conditions for the subsequent further treatment of the VOCs exhaust gas.

[0048] In some embodiments, a temperature sensor, a pressure sensor, and a second glass sight glass are provided on the inner wall of the pipe between the detachable filler 54 and the third nozzle 55 ; wherein the pressure sensor is interlocked with the diagonal flow pipe fan 60 for operation.

[0049] A temperature detection point is set in the second pipeline 50, and a temperature sensor is installed at the temperature detection point. The temperature sensor transmits the temperature data of the temperature detection point to the central control DCS (Distributed Control System) to determine whether the temperature here meets the requirements. If the temperature is higher than the set value, the water spray flow rate of the third nozzle 55 will be increased to reduce the temperature.

[0050] A second glass mirror is provided in the second pipe 50. Through the camera above, the VOCs tail gas treatment situation in the second pipe 50 is transmitted to the monitoring screen in real time through images, and the third nozzle 55 can be manually opened for additional washing. Specifically, the wet dust content in the VOCs tail gas in the second pipe 50 is monitored through the second glass mirror. When the dust is large, the third nozzle 55 can be opened for washing and dust reduction again.

[0051] It should be noted that a camera can be installed through the second glass endoscope, which transmits real-time images here to the central control monitoring screen, and judges the wet dust content in the VOCs exhaust gas by naked eyes and manual experience.

[0052] A pressure measuring point is set in the second pipeline 50, and a pressure sensor is installed at the pressure measuring point. The pressure sensor is interlocked with the diagonal flow duct fan 60 to ensure that the pressure of the entire VOCs exhaust system is always in a balanced state to avoid generating a large negative pressure, thereby avoiding excessive inhalation of air and causing the collected VOCs exhaust gas volume to be too large.

[0053] like Figure 1 As shown, a 90° long radius elbow is installed at the outlet end of the second pipeline 50, and a diagonal flow pipeline fan 60 is located behind the elbow.

[0054] The VOCs tail gas pretreatment system for the coke-out of the carbonization furnace forms a suction force through the upper bridge elbow 30 and the high-pressure jet nozzle (i.e., the first nozzle 31), so as to inhale the VOCs waste gas containing wet dust emitted when the carbonization furnace is coke-out, and saturate and cool the superheated water vapor in the waste gas to reduce the temperature of the waste gas to below 70°C, and then further remove dust and cool the waste gas through the lower bridge elbow 40, the second nozzle 52, and the third nozzle 55 to reduce the temperature of the waste gas to below 55°C, and then defog and dry the waste gas through the detachable baffle 53 and the detachable filler 54, and finally pump it to the next treatment facility through the oblique flow duct fan 60. This method effectively solves the problems that the waste gas has a high temperature and moisture content before it is sent to the washing tower, resulting in poor treatment effect, and that wet dust, tar and other components are easy to settle and adhere to the inner wall of the pipeline, making it difficult to clean. At the same time, the system has low water consumption and low investment cost, and has good advantages of energy saving, consumption reduction, cost reduction and efficiency improvement.

[0055] This embodiment also provides a method for pre-treating VOCs tail gas from coking in a carbonization furnace, using the above-mentioned VOCs tail gas pre-treating system from coking in a carbonization furnace, comprising: Step 100, open the coke outlet gate valve 70, interlock and open the first nozzle 31, form a negative pressure at the suction hood 10 to suck the VOCs tail gas into the upper bridge elbow 30, and the high-pressure jet generated by the first nozzle 31 washes the VOCs tail gas and cools it down to below the temperature T1.

[0056] Specifically, when the coke discharge bin gate valve 70 is opened, the lignite falls into the coke discharge belt, and the exhaust gas that comes out of it quickly escapes into the closed material guide trough of the coke discharge belt. The first nozzle 31 is opened through the interlock to produce a high-pressure jet effect. By forming a suction force at the tail end, a negative pressure is formed at the tail end of the suction hood 10, which can quickly suck the exhaust gas into the upper bridge elbow 30, and then the high-pressure jet generated by the first nozzle 31 quickly washes the exhaust gas and cools it down to below T1.

[0057] In some embodiments, T1 = 70°C.

[0058] In step 200, the VOCs tail gas travels to the lower bridge elbow 40 and is condensed into droplets.

[0059] In the lower bridge elbow 40, the superheated water vapor in the VOCs exhaust gas is saturated and condensed, and begins to condense into droplets with the dust particles in the VOCs exhaust gas as condensation cores.

[0060] When the VOCs exhaust gas carries droplets and contacts the detachable baffle 53, the droplets in the VOCs exhaust gas are captured and collected in the second straight pipe 41 of the lower bridge type elbow 40 through the inertial capture effect of the detachable baffle 53. The liquid level sensor in the second straight pipe 41 detects the liquid level. If the liquid level reaches the ultra-high liquid level HH, the electric drain valve 51 is interlocked to open to discharge the accumulated liquid. If the liquid level reaches the ultra-low liquid level LL, the electric drain valve 51 is interlocked to close.

[0061] In step 300, the second nozzle 52 is started to wash, condense and cool the VOCs exhaust gas to below the temperature T2. The VOCs exhaust gas carries droplets and contacts the detachable baffle 53. The detachable baffle 53 captures the droplets. The VOCs exhaust gas continues to move forward and contacts the detachable filler 54. The detachable filler 54 demists the VOCs exhaust gas.

[0062] In some embodiments, T2 = 55°C.

[0063] After the detachable filler 54 demists the VOCs tail gas, the wet dust content of the VOCs tail gas in the second pipe 50 is observed through the second glass sight glass. When the dust is large, the third nozzle 55 is started to supplement and wash the VOCs tail gas.

[0064] In some embodiments, the third nozzle 55 uses clean soft water to ensure washing and rinsing effects.

[0065] When the coke outlet gate valve 70 is in the closed state, only a small amount of VOCs exhaust gas escapes into the closed space above the belt. The spray pressure value of the first nozzle 31 can be lowered, the timing is M minutes, and then the first nozzle 31 is closed, and the diagonal flow duct fan 60 is closed at the same time to stop the VOCs exhaust gas transportation.

[0066] In some embodiments, M=1.5.

[0067] During the period when the first nozzle 31 is closed, the third nozzle 55 is opened for 3 minutes to regularly flush and clean the detachable baffle 53 and the detachable filler 54. At the same time, the opening time of the third nozzle 55 can be adjusted according to the VOCs tail gas treatment effect, which has the effect of energy saving while satisfying the treatment effect.

[0068] When the first nozzle 31 is closed, the diagonal flow duct fan 60 can be started, and the detachable filler 54 can be removed at the same time, and the VOCs tail gas can be directly sucked into the second pipe 50 through the diagonal flow duct fan 60, and the VOCs tail gas can be washed, cooled, and dusted through the second nozzle 52. This situation is mainly suitable for when the carbonization furnace load is low and the amount of coke tail gas is small, and by closing the first nozzle 31, energy saving and consumption reduction can be further achieved.

[0069] The carbonization furnace load is low, which means that the carbonization furnace load is 0-50%, and the amount of coke exhaust gas is small, which means that "when the coke outlet gate valve 70 is closed, the VOCs exhaust gas is cut off, and only a small amount of VOCs exhaust gas escapes into the operating environment". Since the VOCs exhaust gas is discharged intermittently, the exhaust gas volume is the largest when the coke outlet gate valve 70 is opened, and when the coke outlet gate valve 70 is closed, the exhaust gas volume is cut off, and only a small amount of exhaust gas escapes into the operating environment.

[0070] In some embodiments, the first nozzle 31 uses circulating washing water (ie, uses water in a circulating water tank), and the washing water is replaced regularly according to the water quality and water temperature.

[0071] Step 400: The pressure sensor detects the pressure. If the pressure is higher than P 设定 When the VOCs exhaust gas is sucked by the interlock, the diagonal flow duct fan 60 is started, and the diagonal flow duct fan 60 sucks the VOCs exhaust gas and transports the VOCs exhaust gas to the downstream.

[0072] Specifically, the pressure of the VOCs exhaust gas is measured through the pressure measurement point in the second pipe 50. When the pressure is higher than -300 Pa, the diagonal flow duct fan 60 is started to suck and transport the VOCs exhaust gas backward. When the first nozzle 31 is closed, the diagonal flow duct fan 60 is interlocked and cut off.

[0073] This implementation method takes into account aspects such as exhaust gas extraction and pipeline scaling and blockage, and moves the washing and dust reduction functions from the rear-end tower facilities to the inside of the pipeline. That is, the exhaust gas is sucked in for washing as soon as it is discharged. This not only improves the washing and dust reduction effects, but also eliminates the phenomena of pipeline scaling and serious blockage, while significantly reducing the investment cost and operating expenses of the treatment facilities.

[0074] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present invention, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A VOCs tail gas pretreatment system for coking out of a carbonization furnace, arranged downstream of a coking out bin gate valve (70) of the carbonization furnace, characterized in that: Along the conveying direction of the VOCs tail gas, it includes a first pipeline (20), an upper bridge-type elbow (30), a lower bridge-type elbow (40) and a second pipeline (50) which are sealed and connected in sequence; An air suction hood (10) is sealed and mounted on the inlet end of the first pipeline (20); An oblique-flow duct fan (60) is installed at the outlet end of the second duct (50); A plurality of nozzles are installed in the upper bridge elbow (30) and the second pipeline (50), and the nozzles are interlocked with the coke outlet bin gate valve (70) to control the amount of air sucked into the suction hood (10).

2. The VOCs tail gas pretreatment system for coking out of a carbonization furnace according to claim 1, characterized in that: The upper bridge type curved pipe (30) is an inverted V-shaped structure consisting of a first left inclined pipe and a first right inclined pipe, and a first nozzle (31) is installed in the first right inclined pipe; The first nozzle (31) adopts a pressure regulating nozzle to control the suction force.

3. The VOCs tail gas pretreatment system for coking out of a carbonization furnace according to claim 2 is characterized in that: The upper bridge type elbow (30) is lined with wear-resistant ceramic sheets; The junction of the first left oblique tube and the first right oblique tube vertically extends upward to form a first straight tube (32); A first glass sight glass is installed in the first straight tube (32).

4. The VOCs tail gas pretreatment system for coking out of a carbonization furnace according to claim 3 is characterized in that: The lower bridge type curved pipe (40) is a regular V-shaped structure consisting of a second left inclined pipe and a second right inclined pipe; The junction of the second left oblique tube and the second right oblique tube extends vertically downward to form a second straight tube (41); A liquid level sensor is arranged in the second straight pipe (41); The outlet of the second straight pipe (41) is connected to a drainage pipe, and the drainage pipe leads to a circulating water tank; An electric drain valve (51) is installed in the drain pipe; The liquid level sensor and the electric drain valve (51) operate in an interlocking manner.

5. The VOCs tail gas pretreatment system for coking out of a carbonization furnace according to claim 4, characterized in that: Along the conveying direction of the VOCs tail gas, a second nozzle (52), a detachable baffle (53), a detachable filler (54), and a third nozzle (55) are sequentially installed in the second pipe (50).

6. The VOCs tail gas pretreatment system for coking out of a carbonization furnace according to claim 5, characterized in that: A temperature sensor, a pressure sensor, and a second glass sight glass are provided on the inner wall of the pipe between the detachable filler (54) and the third nozzle (55); Wherein, the pressure sensor operates in an interlocked manner with the diagonal flow duct fan (60).

7. The VOCs tail gas pretreatment system for coking out of a carbonization furnace according to claim 1, characterized in that: A strip of polyurethane tape is bonded to the inlet end of the air suction hood (10).

8. A method for pretreating VOCs tail gas from coking in a carbonization furnace, using the VOCs tail gas pretreatment system from coking in a carbonization furnace according to claim 6, characterized in that: include: The coke outlet bin gate valve (70) is opened, and the first nozzle (31) is interlocked to open, so that negative pressure is formed at the air suction hood (10) to suck the VOCs tail gas into the upper bridge elbow (30), and the high-pressure jet generated by the first nozzle (31) washes the VOCs tail gas and cools it to a temperature below T1; The VOCs tail gas travels into the lower bridge elbow (40) and is condensed into droplets; The second nozzle (52) is started to wash, condense and cool the VOCs tail gas to a temperature below T2, the VOCs tail gas carries droplets and contacts the detachable baffle (53), the detachable baffle (53) captures the droplets, the VOCs tail gas continues to move forward and contacts the detachable filler (54), and the detachable filler (54) demists the VOCs tail gas; The pressure sensor detects the pressure. If the pressure is higher than P 设定 When the VOCs exhaust gas is sucked by the diagonal flow duct fan (60), the diagonal flow duct fan (60) is interlocked to start the VOCs exhaust gas and transport the VOCs exhaust gas to the downstream.

9. The method for pretreating VOCs tail gas from coking furnace according to claim 8, characterized in that: When the VOCs tail gas carries liquid droplets and contacts the detachable baffle (53), the detachable baffle (53) captures the liquid droplets, and the liquid droplets flow downward and are collected in the second straight pipe (41) of the lower bridge elbow (40). The liquid level sensor in the second straight pipe (41) detects the liquid level. If the liquid level reaches an ultra-high liquid level HH, the electric drain valve (51) is interlocked to open to drain the accumulated liquid. If the liquid level reaches an ultra-low liquid level LL, the electric drain valve (51) is interlocked to close. After the detachable filler (54) demists the VOCs tail gas in step 1, the wet dust content of the VOCs tail gas in the second pipe (50) is observed through the second glass sight glass to start the third nozzle (55) to supplement the washing of the VOCs tail gas.

10. The method for pretreating VOCs tail gas from coke in a carbonization furnace according to claim 8 or 9, characterized in that: When the coke outlet bin gate valve (70) is in a closed state, the liquid spraying pressure value of the first nozzle (31) is lowered, a time is set for M minutes, and then the first nozzle (31) is closed, and at the same time, the diagonal flow duct fan (60) is closed to stop the VOCs tail gas transmission.

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