A coking acid-making dry tail gas odor treatment system and method

Abstract

The present application relates to tail gas treatment technical field, disclose a kind of coking acid-making drying tail gas odor treatment system and method, including chimney, alkaline washing tower, heat exchange device, demisting device, coke adsorption device and induced draft fan, cut-off valve for separating lower cavity and upper outlet is equipped in chimney, tail gas is introduced into lower cavity of chimney by pipeline, lower cavity of chimney is also connected by pipeline with the lower part of alkaline washing tower, alkali liquor circulating spraying device is built in alkaline washing tower, the top of alkaline washing tower is connected with heat exchange device by pipeline, heat exchange device is connected with demisting device by pipeline, demisting device is connected with coke adsorption device by pipeline, coke adsorption device is connected with induced draft fan by pipeline, and induced draft fan is used to pass to coke oven for combustion treatment by pipeline after processing tail gas is passed to coke oven for combustion treatment.The present application solves the problem that tail gas is discharged into the environment, causing pollution to the environment;At the same time, cut-off valve can be opened as needed when necessary, and directly discharged through chimney.

Description

Technical Field

[0001] This invention relates to the field of exhaust gas treatment technology, specifically to a system and method for treating odors in coking acid drying exhaust gas. Background Technology

[0002] Currently, industrial exhaust gases from the coal chemical industry are mostly treated by existing treatment devices (such as acid washing towers and water washing towers) before being directly discharged into the air through chimneys. However, existing treatment devices do not thoroughly purify the exhaust gases from acid drying, and direct discharge can easily cause severe odors in the surrounding areas, affecting environmental protection indicators.

[0003] Therefore, there is an urgent need for a coking acid drying tail gas odor treatment system and method to solve the problem that existing treatment devices are not thorough enough in purifying the acid drying tail gas. Summary of the Invention

[0004] This invention addresses the shortcomings of existing technologies by providing a coking acid drying tail gas odor treatment system and method to solve the problem that existing treatment devices do not thoroughly purify the acid drying tail gas.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A coking acid drying tail gas odor treatment system includes a chimney, an alkali scrubbing tower, a heat exchanger, a demister, a coke adsorption device, and an induced draft fan. The chimney is equipped with a shut-off valve to isolate the lower cavity from the upper outlet. Tail gas is introduced into the lower cavity of the chimney through a pipe. The lower cavity of the chimney is also connected to the lower part of the alkali scrubbing tower through a pipe. The alkali scrubbing tower contains an alkali solution circulation spray device. The top of the alkali scrubbing tower is connected to the heat exchanger through a pipe. The heat exchanger is connected to the demister through a pipe. The demister is connected to the coke adsorption device through a pipe. The coke adsorption device is connected to the induced draft fan through a pipe. The induced draft fan is used to transmit the treated tail gas to the coke oven for combustion treatment through the pipe.

[0007] To optimize the above technical solution, the specific measures also include: Furthermore, the alkaline solution circulating spraying device includes a circulating pump, a metering pump, and an alkaline storage device for storing alkaline solution. The alkaline washing tower is provided with a demineralized water inlet for supplying demineralized water and an alkaline solution inlet for connecting the alkaline storage device. The circulating pump is used to connect the bottom and top of the alkaline washing tower and to draw the diluted alkaline solution located at the bottom of the alkaline washing tower to the top for spraying. The metering pump is used to draw alkaline solution from the alkaline storage device and supply it to the alkaline washing tower.

[0008] Furthermore, the bottom of the alkaline washing tower is also provided with a steam inlet for supplying steam.

[0009] Furthermore, the demisting device employs a wire mesh demisting device.

[0010] Furthermore, the top of the alkali washing tower is connected to a heat exchange device via a first pipe and to a coke adsorption device via a second pipe. The first and second pipes are controlled by valves.

[0011] Furthermore, the coke adsorption device includes several coke bins connected in parallel, and the demisting device is connected to the air inlet of each coke bin through several pipes. The air outlet of each coke bin is connected to an induced draft fan through a pipe.

[0012] Furthermore, it also includes a submersible tank and a submersible pump. The waste liquid from the alkali washing tower, heat exchange device, and coke adsorption device is discharged to the submersible tank through pipelines, and the liquid in the submersible tank is discharged to the ammonia stripping system through the submersible pump.

[0013] Furthermore, it also includes an emergency discharge device, which includes a shut-off valve, a vent valve, and an additional coke bin. The shut-off valve is installed on the pipe connecting the induced draft fan to the coke oven. The pipe between the shut-off valve and the induced draft fan is connected to the air inlet of the coke bin through a branch pipe. The air outlet of the coke bin is connected to the upper outlet of the shut-off valve inside the chimney through a pipe.

[0014] Furthermore, it also includes instrumentation devices installed on the pipeline between the shut-off valve and the induced draft fan. The instrumentation devices include a pressure transmitter and a combustible gas alarm.

[0015] Furthermore, a method of use, applied to the above-mentioned coking acid drying tail gas odor treatment system, includes the following steps: The exhaust gas after passing through the cavity below the chimney is introduced into an alkaline scrubbing tower for alkalinization treatment. Then, it is successively cooled by a heat exchanger, demisted by a demister, and adsorbed by a coke adsorption device. Finally, the treated exhaust gas is recovered by an induced draft fan and transported to the coke oven for combustion. When necessary, the shut-off valve is opened and the exhaust gas is directly discharged through the chimney.

[0016] The beneficial effects of this invention are: This invention, through the configuration of a chimney, alkaline scrubbing tower, heat exchanger, demister, coke adsorption device, and induced draft fan, directs the exhaust gas, after passing through the cavity below the chimney, into the alkaline scrubbing tower for alkalinization treatment. Then, the gas sequentially passes through the heat exchanger for cooling, the demister for demisting, and the coke adsorption device for adsorption. Finally, the induced draft fan recovers and transports the treated exhaust gas to the coke oven for combustion. This system effectively solves the environmental pollution problem caused by exhaust gas emissions. Furthermore, the shut-off valve ensures proper exhaust gas treatment under normal conditions, and allows for direct discharge through the chimney in necessary special circumstances. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the usage method of the coking acid drying tail gas odor treatment system proposed in this invention. Detailed Implementation

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0019] An embodiment of the present invention provides a coking acid drying tail gas odor treatment system, comprising a chimney, an alkali scrubbing tower, a heat exchange device, a demister, a coke adsorption device, and an induced draft fan. The chimney is equipped with a shut-off valve to isolate the lower cavity from the upper outlet. Tail gas is introduced into the lower cavity of the chimney through a pipe. The lower cavity of the chimney is also connected to the lower part of the alkali scrubbing tower through a pipe. The alkali scrubbing tower contains an alkali solution circulation spray device. The top of the alkali scrubbing tower is connected to the heat exchange device through a pipe. The heat exchange device is connected to the demister through a pipe. The demister is connected to the coke adsorption device through a pipe. The coke adsorption device is connected to the induced draft fan through a pipe. The induced draft fan is used to transmit the treated tail gas to the coke oven for combustion treatment through the pipe.

[0020] This invention, through the configuration of a chimney, alkaline scrubbing tower, heat exchanger, demister, coke adsorption device, and induced draft fan, directs the exhaust gas, after passing through the cavity below the chimney, into the alkaline scrubbing tower for alkalinization treatment. Then, the gas sequentially passes through the heat exchanger for cooling, the demister for demisting, and the coke adsorption device for adsorption. Finally, the induced draft fan recovers and transports the treated exhaust gas to the coke oven for combustion. This system effectively solves the environmental pollution problem caused by exhaust gas emissions. Furthermore, the shut-off valve ensures proper exhaust gas treatment under normal conditions, and allows for direct discharge through the chimney in necessary special circumstances.

[0021] In the above scheme, the heat exchange device can use low-temperature water for cooling. The low-temperature water comes from the desulfurization area, uses the plant's low-temperature water as the heat exchange medium, and returns to the low-temperature water system for circulation after the cooling water has been cooled.

[0022] In the above scheme, the pipes used to introduce exhaust gas into the chimney can be made of fiberglass.

[0023] In the specific embodiment one described above: The alkaline solution circulating spray device includes a circulating pump, a metering pump, and an alkaline storage device for storing alkaline solution. The alkaline washing tower is equipped with a demineralized water inlet for supplying demineralized water and an alkaline solution inlet for connecting to the alkaline storage device. The circulating pump is used to connect the bottom and upper sidewalls of the alkaline washing tower and to draw the diluted alkaline solution located at the bottom of the alkaline washing tower to the top for spraying. The metering pump is used to draw alkaline solution from the alkaline storage device and supply it to the alkaline washing tower.

[0024] In this embodiment, by setting up a circulating pump, a metering pump, and an alkali storage device for storing alkali solution, the alkali solution diluted with demineralized water can be circulated and pumped to the upper or middle part of the alkali washing tower for spraying, thereby ensuring the recycling of alkali solution and the treatment effect on waste gas.

[0025] In the above scheme, at least two circulating pumps can be used, with one in use and one on standby.

[0026] In a further specific embodiment based on the above, the bottom of the alkali washing tower is also provided with a steam inlet for supplying steam.

[0027] In this embodiment, when the exhaust gas delivery pipeline is long, liquid accumulation and blockage are likely to occur. Steam can be introduced for purging to ensure long-term stable operation of the system.

[0028] In the second specific embodiment described above: The demister device uses a wire mesh demister. In this embodiment, the wire mesh demister can remove large droplets from the exhaust gas, facilitating the subsequent adsorption and treatment of the exhaust gas by the coke adsorption device.

[0029] In the specific embodiment three described above: The top of the alkali washing tower is connected to a heat exchange device via a first pipe and to a coke adsorption device via a second pipe. The first and second pipes are controlled by valves.

[0030] In this embodiment, when the heat exchange device and the demisting device malfunction or need cleaning, the first branch pipe can be closed and the second branch pipe can be opened to temporarily direct the exhaust gas directly to the coke adsorption device to ensure the normal flow of the exhaust gas; and after the treatment is completed, the first branch pipe can be reopened and the second branch pipe can be closed to restore normal operation.

[0031] In the specific embodiment four described above: The coke adsorption device includes several coke bins connected in parallel. The demisting device is connected to the air inlet of each coke bin through several pipes, and the air outlet of each coke bin is connected to an induced draft fan through a pipe.

[0032] In this embodiment, the filtration and adsorption effect of the tail gas can be improved by using several coke bins connected in parallel. In the above scheme, the coke bins use on-site coke as the adsorption medium, with a particle diameter of 20-50mm, to adsorb residual mist droplets and acidic substances in the tail gas; the several coke bins can be used in a partially open and partially standby manner, and the opening and closing of the air inlet can be controlled by preset valves as needed; the connection between the air inlet of each coke bin and the demister, as well as the connection between the air outlet and the induced draft fan, can all adopt a design of main pipe and branch pipes.

[0033] In the specific embodiment five described above: It also includes a submersible tank and a submersible pump. Waste liquid from the alkali washing tower, heat exchanger and coke adsorption unit is discharged to the submersible tank through pipelines. The liquid in the submersible tank is discharged to the ammonia stripping system through the submersible pump.

[0034] In this embodiment, the alkali washing tower can also be directly connected to the ammonia stripping system to return the waste alkali solution to the ammonia stripping system; the discharge of the coke filter mentioned above is equipped with a safety water seal as needed to ensure that the discharge does not leak air.

[0035] In the specific embodiment six described above: It also includes an emergency discharge device, which includes a shut-off valve, a vent valve, and an additional coke bin. The shut-off valve is installed on the pipe connecting the induced draft fan to the coke oven. The pipe between the shut-off valve and the induced draft fan is connected to the air inlet of the coke bin through a branch pipe. The air outlet of the coke bin is connected to the upper outlet of the shut-off valve inside the chimney through a pipe.

[0036] In this embodiment, the installation of a shut-off valve, a vent valve, and an additional coke bin ensures that the shut-off valve is open and the system operates normally under normal conditions. In case of an emergency, the shut-off valve closes, the vent valve opens, and the gas is directly filtered again through the connected coke bin before being discharged through the chimney.

[0037] In a further specific embodiment based on the above, an instrumentation device is also included, which is installed on the pipeline between the shut-off valve and the induced draft fan. The instrumentation device includes a pressure transmitter and a combustible gas alarm.

[0038] In this embodiment, by setting up the instrument device, the gas condition in the pipeline can be monitored to determine whether there are unexpected situations such as induced draft fan failure or pipeline blockage, thereby triggering the on / off of the shut-off valve and the vent valve.

[0039] A method of use, applied to the above-mentioned coking acid drying tail gas odor treatment system, includes the following steps: The exhaust gas after passing through the cavity below the chimney is introduced into an alkaline scrubbing tower for alkalinization treatment. Then, it is successively cooled by a heat exchanger, demisted by a demister, and adsorbed by a coke adsorption device. Finally, the treated exhaust gas is recovered by an induced draft fan and transported to the coke oven for combustion. When necessary, the shut-off valve is opened and the exhaust gas is directly discharged through the chimney.

[0040] As attached Figure 1 As shown, a specific embodiment of the present invention is as follows: The exhaust gas after passing through the cavity below the chimney is introduced into the alkaline washing tower for alkaline washing. The alkaline washing tower uses a circulating pump to draw alkaline solution diluted with demineralized water to wash the exhaust gas. The circulating pump is used to draw the diluted alkaline solution to the upper or middle part of the alkaline washing tower for spraying. At the same time, the metering pump of the alkaline storage device automatically replenishes the alkaline in the alkaline washing tower as needed. An independent and automatic replenishment and drainage system can be set up as needed. The alkaline washing tower is equipped with devices such as a remote pH meter and a level gauge. When the pH value is lower than the set value of 9.5, the metering pump will automatically replenish the alkaline solution. When the level gauge detects that the value has reached the set value of 1.2 meters, the liquid can be automatically and quantitatively drained into the submerged tank, or the waste alkaline solution can be returned to the ammonia production system. After being washed in the alkaline scrubbing tower, the hydrogen sulfide content of the tail gas can be reduced from 100mg / m³ to ≤20mg / m³. Then it is passed into the heat exchanger, where it is cooled to below 30℃. After that, it is passed into the demister for deep demisting. Then it is further passed into the coke adsorption unit for adsorption and filtration. Finally, it is transported to the coke oven for combustion by the induced draft fan.

[0041] After purification by the above system, the hydrogen sulfide content in the exhaust gas is reduced to below 20 mg / m³, the exhaust gas temperature is reduced to below 30°C, the combustible gas concentration is below 25 LEL, and the oxygen content is in the range of 19-21%, meeting the conditions for being transported to the coke oven for combustion treatment.

[0042] When the heat exchanger and demister malfunction or require cleaning, the first pipe can be closed and the second pipe opened to temporarily direct the exhaust gas directly to the coke adsorption device to ensure normal exhaust gas flow. After the treatment is completed, the first pipe can be reopened and the second pipe closed to restore normal operation.

[0043] When the instrument detects abnormal data, such as real-time monitoring of the combustible gas content in the exhaust gas, an alarm is triggered when the combustible gas content is ≥25 LEL, and when it is ≥50 LEL, the shut-off valve is closed and the vent valve is opened, so that the gas is directly filtered again through the connected coke bin and then discharged urgently through the chimney.

[0044] The aforementioned alkaline solution used for washing comes from the chemical oil depot area and is introduced into the alkaline storage device through pipelines; the aforementioned demineralized water is used to dilute the high-concentration alkaline solution, prevent alkaline solution crystallization from clogging the nozzles, and prevent the formation of scale from affecting the desulfurization efficiency; the aforementioned induced draft fan is frequency-controlled.

[0045] It should be noted that the terms such as "upper", "lower", "left", "right", "front", and "back" used in the invention are only for clarity of description and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0046] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0047] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that those skilled in the art will understand that various changes, modifications, substitutions, refinements, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. These variations should be considered within the scope of protection of the present invention, which is defined by the appended claims and their equivalents.

Claims

1. A coking acid drying tail gas odor treatment system, characterized in that: The system includes a chimney, an alkali scrubbing tower, a heat exchanger, a demister, a coke adsorption unit, and an induced draft fan. The chimney is equipped with a shut-off valve to separate the lower cavity from the upper outlet. The lower cavity of the chimney introduces exhaust gas through a pipe, and is also connected to the lower part of the alkali scrubbing tower via a pipe. The alkali scrubbing tower contains an alkali solution circulation spray device. The top of the alkali scrubbing tower is connected to the heat exchanger via a pipe, which in turn is connected to the demister via a pipe. The demister is connected to the coke adsorption unit via a pipe, and the coke adsorption unit is connected to the induced draft fan via a pipe. The induced draft fan is used to transmit the treated exhaust gas through the pipe to the coke oven for combustion.

2. The odor treatment system for coking acid drying tail gas according to claim 1, characterized in that: The alkaline solution circulating spray device includes a circulating pump, a metering pump, and an alkaline storage device for storing alkaline solution. The alkaline washing tower is provided with a demineralized water inlet for supplying demineralized water and an alkaline solution inlet for connecting to the alkaline storage device. The circulating pump is used to connect the bottom and top of the alkaline washing tower and to draw the diluted alkaline solution located at the bottom of the alkaline washing tower to the top for spraying. The metering pump is used to draw alkaline solution from the alkaline storage device and supply it to the alkaline washing tower.

3. The odor treatment system for coking acid drying tail gas according to claim 2, characterized in that: The bottom of the alkaline washing tower is also equipped with a steam inlet for supplying steam.

4. The odor treatment system for coking acid drying tail gas according to claim 1, characterized in that: The demisting device is a wire mesh demisting device.

5. The odor treatment system for coking acid drying tail gas according to claim 1, characterized in that: The top of the alkaline washing tower is connected to a heat exchange device via a first pipe and to a coke adsorption device via a second pipe. The first and second pipes are controlled by valves.

6. The odor treatment system for coking acid drying tail gas according to claim 1, characterized in that: The coke adsorption device includes several coke bins connected in parallel. The demisting device is connected to the air inlet of each coke bin through several pipes, and the air outlet of each coke bin is connected to an induced draft fan through a pipe.

7. The odor treatment system for coking acid drying tail gas according to claim 1, characterized in that: It also includes a submersible tank and a submersible pump. The waste liquid from the alkali washing tower, heat exchange device and coke adsorption device is discharged to the submersible tank through pipelines, and the liquid in the submersible tank is discharged to the ammonia stripping system through the submersible pump.

8. The odor treatment system for coking acid drying tail gas according to claim 1, characterized in that: It also includes an emergency discharge device, which includes a shut-off valve, a venting valve, and an additional coke bin. The shut-off valve is installed on the pipe connecting the induced draft fan to the coke oven. The pipe between the shut-off valve and the induced draft fan is connected to the air inlet of the coke bin through a branch pipe. The air outlet of the coke bin is connected to the upper outlet of the shut-off valve inside the chimney through a pipe.

9. The odor treatment system for coking acid drying tail gas according to claim 8, characterized in that: It also includes instrumentation devices, which are installed on the pipeline between the shut-off valve and the induced draft fan. The instrumentation devices include pressure transmitters and combustible gas detectors.

10. A method of use, applied to the coking acid drying tail gas odor treatment system according to any one of claims 1 to 9, characterized in that, Includes the following steps: The exhaust gas after passing through the cavity below the chimney is introduced into an alkaline scrubbing tower for alkalinization treatment. Then, it is successively cooled by a heat exchanger, demisted by a demister, and adsorbed by a coke adsorption device. Finally, the treated exhaust gas is recovered by an induced draft fan and transported to the coke oven for combustion. When necessary, the shut-off valve is opened and the exhaust gas is directly discharged through the chimney.

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