CN108592054B - A coking plant VOCs treatment system - Google Patents

Abstract

The invention relates to a VOCs treatment system in a coking plant, comprising a control system, a combustion treatment system and a negative pressure recovery system. The invention can effectively treat the VOCs, can reduce the pollution of the VOCs to the environment to the greatest extent, and complies with the provisions of the "Coking Chemical Industry Pollutant Emission Standard" GB16171-2012.

Description

A coking plant VOCs treatment system

technical field

The invention relates to the technical field of volatile organic compound VOCs treatment, in particular to a coking plant VOCs treatment system.

Background technique

VOCs (volatile organic compounds) volatile organic compounds refer to organic compounds whose saturated vapor pressure is greater than 133.32 Pa at normal temperature and whose boiling point is below 50~260 °C at normal pressure, or any organic solid or liquid that can volatilize at normal temperature and pressure.

In the process of gas purification and production, exhaust gas will be generated due to the flow of various media and the storage pressure of gas. During normal production, some production devices such as storage tanks will also emit some waste gas. These exhaust gas and waste gas contain a large amount of VOCs. The sources of VOCs generated in the coking production process are as follows: 1. During the production process, the transfer between chemical product tanks, the discharge of the internal gas through the venting pipe during feeding, or the volatilized gas of the gas at elevated temperature; 2. During the production process 3. Short-term emptying under abnormal equipment and other abnormal production conditions; 4. Exhaust gas from equipment leakage; 5. Exhaust gas from chemical production tank overflow; 6. Chemical reaction Some gases generated during the production process.

At present, the treatment of VOCs mainly adopts the negative pressure recovery method, that is, the VOCs discharged from each tank and tank are recovered into the negative pressure gas pipeline. However, in the practical application of this method, it is found that there are the following technical problems: all tanks and tanks connected to the negative pressure gas pipeline are equipped with breathing valves. When the pressure is greater than +2000Pa, the breathing valve will automatically open, and the waste gas in the tank and tank will be discharged into the atmosphere, causing environmental pollution. . When the negative pressure inside the tank and tank is greater than -300Pa, the breathing valve will automatically open, and air will be inhaled. Since the inhaled air will enter the negative pressure gas pipeline together with VOCs, there is a high risk of explosion.

For some special discharge points: tar ammonia clarifier, desulfurization regeneration tower tail gas, loading crane, sulfur melting kettle sulfur connection and thiamine mother liquor full flow tank, these five types of discharge points are difficult to avoid air entry or other discharge points during operation. The oxygen content of the discharge itself is relatively high. If these types of discharge points are connected to the negative pressure gas pipeline, it is easy to explode, so these types of discharge points cannot be connected to the negative pressure gas pipeline.

At present, the emissions that cannot be connected to the negative pressure gas pipeline generally adopt the following treatment methods: adsorption method, absorption method, condensation method, membrane separation method, combustion method, biological filtration method, plasma method and photocatalytic oxidation method. Although the cost of the adsorption method is low, the adsorption capacity is small, and it is easy to have the problem of adsorption saturation and adsorption specificity; the adsorption method is relatively simple, and the equipment investment is low, but the recovery efficiency of this process is low, and it is difficult for environmental protection requirements to be high. Reach the allowable oil and gas emission standards; although the condensation method has a high degree of automation, convenient maintenance, and good safety, it consumes a lot of electricity and is not "energy saving and emission reduction" in the true sense; although the membrane separation method has a simple process, a high recovery rate, and no The characteristics of secondary pollution, but the membrane production rate is low, the price is high, and the membrane life is short; although the biological filtration method has high treatment efficiency and simple process, the removal rate of VOCs is low; although the plasma method and photocatalytic oxidation method have high treatment efficiency, The operating cost is low, but the treatment efficiency of high-concentration VOCs is average; the combustion method is the most thorough, and the main products of its combustion are water and carbon dioxide, which pollutes the air very little, but the safety of the current equipment is very low, which hinders the combustion Promotion and use of the law.

SUMMARY OF THE INVENTION

The invention provides a VOCs treatment system in a coking plant.

The technical scheme of the present invention is realized as follows: a VOCs treatment system in a coking plant, including a control system, a combustion treatment system and a negative pressure recovery system;

The negative pressure recovery system includes a plurality of exhaust gas discharge groups, each of which includes a plurality of exhaust gas discharge points, and the pressure in each exhaust gas discharge point is maintained within a range that can keep the breathing valve of each discharge point open all the time. Inside;

The combustion treatment system includes an exhaust gas collection module, an exhaust gas conveying module, and an exhaust gas treatment module sequentially connected by pipes; the exhaust gas treatment module includes two exhaust gas treatment units, each of which includes a mixer and a coke oven, and the exhaust gas is passed through the exhaust gas treatment unit. The exhaust gas delivered by the conveying module is evenly distributed to the two exhaust gas treatment units. The exhaust gas entering each exhaust gas treatment unit is mixed with the flue gas from the coke oven general flue in the mixer and then enters the coke oven through the exhaust gas switch for combustion. .

As a preferred technical solution, the waste gas collection module includes multiple types of waste gas discharge points, and the types of waste gas discharge points include: tar ammonia water clarifier, desulfurization regeneration tower, loading crane, sulfur melting kettle and thiamine mother liquor overflow tank.

As a preferred technical solution, the slag discharge port of the tar ammonia water clarification tank, the discharge port of the loading crane pipe and the sulfur discharge pipe of the sulfur melting kettle are all provided with sealing devices, and each sealing device is communicated with the main pipeline through a branch pipe. The discharge port of the desulfurization regeneration tower and the discharge port of the thiamine mother liquor overflow tank are directly connected with the main pipeline through branch pipes, and the branch pipes connecting each exhaust gas discharge point are connected with automatic regulating valve I and pressure transmitter I. The transmitter I is connected to the input end of the control system, and the automatic regulating valve I is connected to the output end of the control system.

As a preferred technical solution, the exhaust gas conveying module includes a fan connected to the main pipeline, and a check valve I arranged behind the fan along the conveying direction of the main pipeline.

As a preferred technical solution, the exhaust gas conveying module includes a fan connected to the main pipeline, a check valve I and a quick cut-off valve I arranged behind the fan along the conveying direction of the main pipeline, the quick cut-off valve I and the output of the control system The main pipeline between the fan and the check valve I is connected to the chimney through a pipeline, and the pipeline is connected to a quick cut-off valve II, which is connected to the output end of the control system.

As a preferred technical solution, the general flue of each coke oven is communicated with the input end of the mixer through a pipeline, and the pipeline connecting the general flue of the coke oven and the mixer is connected with a suction fan and a gate valve. It is electrically connected with the output end of the control system; the mixer of each exhaust gas treatment unit is communicated with the main pipeline through a pipeline.

As a preferred technical solution, one of the pipelines connecting the mixer and the main pipeline is connected with an automatic regulating valve III and a pressure transmitter III, and the automatic regulating valve III is electrically connected with the output end of the control system; The other pipeline is connected to the manual regulating valve I and the pressure transmitter III; the pressure transmitter III is connected to the input end of the control system, and a combustible gas analyzer is installed at the output end of each mixer. Control system input circuit connection.

As a preferred technical solution, each exhaust gas discharge group is connected to the negative pressure gas pipeline through a main pipeline, and each main pipeline is connected to an automatic regulating valve II and a pressure transmitter II, and the pressure transmitter II is connected to the control system. The input end circuit is connected, the automatic regulating valve II is connected with the output end circuit of the control system; the negative pressure gas pipeline located behind the multiple exhaust gas discharge groups along the conveying direction of the negative pressure gas pipeline is connected to the check valve II and the quick shut-off valve IV, the quick shut-off valve IV is connected to the output end of the control system in a circuit.

As a preferred technical solution, each exhaust gas discharge group includes a plurality of exhaust gas discharge points, the discharge port of each exhaust gas discharge point is connected with the main pipeline corresponding to the exhaust gas discharge group through an air duct, and each air duct is connected with a manual Regulating valve II.

As a preferred technical solution, the exhaust gas discharge points included in the multiple exhaust gas emission groups are specifically: reservoir area (crude benzene storage tank, tar storage tank, low-level vent tank); drum cooling (tar intermediate tank, residual ammonia tank, circulating ammonia tank) , low-level venting tank, initial cooling spray tank, light tar tank, water-sealed storage tank in front of the machine); desulfurization (liquid accumulation tank, liquid storage tank, accident tank, desulfurization liquid circulation tank, molten sulfur clear liquid storage tank, foam tank , auxiliary salt liquid tank, pump room venting tank); ammonium sulfate (mother liquor storage tank, low-level venting tank; crude benzene, crude benzene intermediate tank, lean oil tank, venting tank, oil-water separator, control separator, crude benzene non-condenser).

Owing to adopting the above-mentioned technical scheme, the present invention has the following outstanding beneficial effects:

1. The exhaust gas discharge points that can be connected to the negative pressure gas pipeline are controlled in groups. Each exhaust gas discharge group is adjusted by the whole group of automatic regulating valve II on the main road, and the single exhaust gas discharge point is adjusted by manual adjustment valve II. By adjusting the opening degree of the manual regulating valve II and the automatic regulating valve II, the pressure of the tank at each exhaust gas discharge point is adjusted, so as to adjust the change of the pressure in the tank feeding or exhausting process. The pressure of each exhaust discharge point is controlled between -200 ~ +200Pa, so the breathing valve of each discharge point will not be opened from beginning to end, neither inhaling air nor discharging exhaust gas into the atmosphere.

2. For several types of discharge points that cannot be connected to the negative pressure gas pipeline, the present invention adopts the method of mixing VOCs with coke oven flue gas and combustion-supporting air to reduce the original concentration of VOCs, and the diluted VOCs can be safely in the coke oven. Therefore, the coking VOCs can be safely, efficiently and thoroughly cleaned, and the pollution of VOCs to the environment can be reduced to the greatest extent.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

FIG. 1 is a schematic structural diagram of a negative pressure recovery system in Embodiment 1 of the present invention.

FIG. 2 is a schematic structural diagram of a sealing device I according to Embodiment 1 of the present invention.

FIG. 3 is a schematic structural diagram of the sealing device II of Embodiment 1 of the present invention.

FIG. 4 is a schematic structural diagram of the sealing device III in Embodiment 1 of the present invention.

FIG. 5 is a schematic diagram of the control principle of the combustion treatment system in Embodiment 1 of the present invention.

FIG. 6 is a schematic diagram of the control principle of the combustion treatment system in Embodiment 2 of the present invention.

In the figure: 1-slag discharge port; 2-sealing cover; 3-slag receiving hopper; 4-discharge port; 5-seal plug; 6-collection cavity; 7-outlet port; 8-branch pipe; 9-automatic regulating valve Ⅰ; 10-Sulfur discharge solenoid valve; 11-Cover body; 12-Hopper; 13-Open; 14-Baffle plate; 15-Load cell; 16-Sulfur discharge pipe; 17-Main pipeline; 18-Negative pressure gas Pipeline; 19-automatic regulating valve II; 20-pressure transmitter II; 21-check valve II; 22-quick cut-off valve IV; 23-air pipe;

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Embodiment 1: The present invention includes a control system, a combustion processing system and a negative pressure recovery system, and the control system is a programmable logic controller or a distributed control system.

As shown in FIG. 1 , the negative pressure recovery system includes a plurality of exhaust gas discharge groups, and each exhaust gas discharge group includes a plurality of exhaust gas discharge points, and the pressure in each exhaust gas discharge point is maintained at a level that enables the breathing of each discharge point. Within the range where the valve is not open all the time; each exhaust gas discharge group is connected to the negative pressure gas pipeline 18 through a main pipeline 17, and each main pipeline 17 is connected to an automatic regulating valve II19 and a pressure transmitter II20, and the pressure changes. The transmitter II20 is connected to the input end circuit of the control system, the automatic regulating valve II19 is connected to the output end circuit of the control system, and the pressure transmitter II20 can convert the gas pressure parameter sensed by the load cell sensor into a standard electrical signal And transmitted to the control system, the control system adjusts the pressure, flow and other parameters of the medium by controlling the automatic regulating valve II19. The main line 17 is connected with an automatic regulating valve II19 and a pressure transmitter II20, which can be used to adjust the overall exhaust pressure of an exhaust emission group corresponding to the main line 17, so as to realize the overall pressure regulation of each exhaust emission group.

The negative pressure gas pipeline 18 located behind the multiple exhaust gas discharge groups along the conveying direction of the negative pressure gas pipeline 18 is connected with a check valve II21 and a quick cut-off valve IV22. The valve IV22 can control the cutting, connecting or switching of the fluid in the negative pressure gas pipeline 18 by accepting the instructions sent by the control system. Check valve II21 is an automatic valve whose main function is to prevent the backflow of the medium. The circuit connection relationship between the automatic regulating valve II19, the pressure transmitter II20, and the quick shut-off valve IV22 and the control system are known in the prior art, and will not be repeated here.

In order to increase the safety of use, the oxygen content detector (not marked in the figure) is connected to the negative pressure gas pipeline 18 located behind the multiple exhaust gas discharge groups along the conveying direction of the negative pressure gas pipeline 18. The oxygen content detector is connected to the control system. The input terminal is connected to the circuit, and the oxygen content detector is located in front of the quick shut-off valve IV22. The oxygen detector is used to detect the oxygen content. When the oxygen content exceeds the standard, the control system sends an instruction to close the quick shut-off valve IV22.

Each exhaust gas discharge group includes a plurality of exhaust gas discharge points, the discharge port of each exhaust gas discharge point is communicated with the main pipeline 17 corresponding to the exhaust gas discharge group through the air pipe 23, and each air pipe 23 is connected to the manual regulating valve II 24 , the flow and pressure of the medium at each discharge point can be individually adjusted through the manual adjustment valve II24. When grouping, generally, several exhaust emission points with similar distances are grouped into one group.

The exhaust gas discharge points included in multiple exhaust gas emission groups are: reservoir area (crude benzene storage tank, tar storage tank, low-level venting tank); drum cooling (tar intermediate tank, residual ammonia tank, circulating ammonia tank, low-level venting tank, initial venting tank); Cold spray tank, light tar tank, water-sealed storage tank in front of machine); desulfurization (liquid accumulation tank, liquid storage tank, accident tank, desulfurization liquid circulation tank, molten sulfur clear liquid storage tank, foam tank, auxiliary salt clear liquid tank , pump room venting tank); ammonium sulfate (mother liquor storage tank, low-level venting tank); crude benzene (crude benzene intermediate tank, lean oil tank, venting tank, oil-water separator, control separator, crude benzene non-condenser).

As shown in FIG. 5 , the combustion treatment system includes an exhaust gas collection module, an exhaust gas delivery module, and an exhaust gas treatment module that are sequentially connected through pipes; the exhaust gas treatment module includes two exhaust gas treatment units, each of which includes a mixer and coke oven, the waste gas delivered by the waste gas delivery module is evenly distributed to the two waste gas treatment units, and the waste gas entering each waste gas treatment unit is mixed with the flue gas from the coke oven general flue in the mixer and then enters each coke oven. Combustion chamber for combustion.

The waste gas collection module includes multiple types of waste gas discharge points, each type of waste gas discharge point is equipped with a breathing valve, and the types of waste gas discharge points include: tar ammonia water clarifier, desulfurization regeneration tower, loading crane, sulfur melting kettle and thiamine mother liquor Full launder. The slag discharge port of the tar ammonia water clarification tank, the discharge port of the loading crane pipe and the sulfur discharge pipe of the sulphur melting kettle are all provided with sealing devices, and each sealing device is communicated with the main pipeline through a branch pipe. The discharge ports of the thiamine mother liquor full flow tank are directly connected to the main pipeline through branch pipes, and the branch pipes connecting each type of waste gas discharge point are connected with automatic regulating valve I and pressure transmitter I. The pressure transmitter I is connected to the control The input end of the system is connected to the circuit, the automatic regulating valve I is connected to the output end of the control system, and the pressure transmitter I can convert the gas pressure parameter sensed by the load cell sensor into a standard electrical signal and transmit it to the control system. The system adjusts the pressure, flow and other parameters of the medium at each exhaust gas discharge point by controlling the automatic regulating valve I. The circuit connection relationship between the automatic regulating valve I, the pressure transmitter I and the control system is known in the prior art, and will not be described in detail here. . An automatic vent valve (not marked in the figure) is connected to the branch pipe connected to the discharge port of the desulfurization regeneration tower. The automatic vent valve is connected to the output end of the control system. The automatic vent valve can be automatically opened and vented under the control of the control system. The automatic regulating valve I connected to the branch pipe connected to the discharge port of the desulfurization regeneration tower is always open.

For the convenience of description, the sealing device installed at the slag discharge port of the tar ammonia clarification tank is named as sealing device I, the sealing device installed at the discharge port of the loading crane pipe is named as sealing device II, and the sealing device installed at the sulfur discharge pipe of the sulfur melting kettle is named as sealing device II. The sealing device is named as sealing device III.

As shown in Figure 2, the sealing device I includes a sealing cover 2 fixed on the slag discharge port 1 of the tar ammonia water clarification tank and a slag receiving hopper 3 located below the sealing cover 2 and fastened together with the sealing cover 2, The size of the lower opening of the sealing cover 2 is adapted to the size of the upper opening of the slag receiving hopper 3 , and the sealing cover 2 communicates with the main pipeline through the branch pipe 8 . The slag receiving hopper 3 can be moved manually to change the position of the slag receiving hopper 3 to facilitate material receiving and unloading. When the sealing cover 2 and the slag receiving hopper 3 are completely buckled together, a formation is formed between the sealing cover 2 and the slag receiving hopper 3. A relatively closed space can effectively prevent the exhaust gas from volatilizing into the air during slag discharge. There is a scraper in the slag discharge port 1. The motor of the scraper is connected with the output end of the control system. When the motor starts, the motor will transmit the signal to the control system synchronously, and the control system will issue an instruction to open the connection seal. 2, the automatic regulating valve I on the branch pipe, and the negative pressure generated by the exhaust gas delivery module will lead the volatile sulfur to the main pipeline. When the slag discharge is completed and the motor stops working, the motor will transmit a signal to the control system, and the control system will issue an instruction to close the automatic regulating valve I on the branch pipe connected to the sealing cover 2 .

As shown in FIG. 3 , the sealing device II is to cover the sealing plug 5 at the discharge port 4 of the loading crane pipe. The sealing plug 5 is provided with a collection cavity 6, and the collection cavity 6 is provided with an outlet 7, so The outlet 7 is communicated with the main pipeline through the branch pipe 8, and the gap between the discharge port 4 of the loading crane pipe and the injection port of the transport vehicle can be blocked by the sealing plug 5, thereby preventing the exhaust gas from volatilizing into the air during the loading process. The electric pump connected to the loading crane pipe is connected to the input end circuit of the control system. When the electric pump starts, the electric pump will transmit the signal to the control system synchronously, and the control system will issue an instruction to open the branch pipe 8 connected to the sealing plug 5. The automatic regulating valve I9 is generated, and the negative pressure is generated by the exhaust gas delivery module to lead the volatile sulfur to the exhaust gas treatment module. When the loading is completed and the electric pump stops, the electric pump will transmit a signal to the control system, and the control system will issue an instruction to close the automatic regulating valve I9 on the branch pipe 8 connected to the sealing plug 5.

As shown in FIG. 4 , the sealing device III includes a cover body 11 and a hopper 12 . One side of the cover body 11 is provided with an opening 13 that communicates with the inside and the outside of the cover body 11 , and a baffle 14 capable of opening and closing the opening 13 is provided at the opening 13 . A load cell 15 is installed on the inner bottom surface of the cover body 11 , a sulfur discharge pipe 16 whose end extends into the inside of the cover body 11 is arranged above the load cell 15 , and a sulfur discharge solenoid valve 10 is installed on the sulfur discharge pipe 16 . The load cell 15 is electrically connected to the input end of the control system, and the sulfur discharge solenoid valve 10 is electrically connected to the output end of the control system. The cover body 11 communicates with the main pipeline through the branch pipe 8 . When the baffle 14 blocks the opening 13, the inside of the cover 11 is in a relatively closed environment, which can effectively prevent the high-temperature liquid sulfur from volatilizing into the outside air during sulfur discharge, causing environmental pollution. The exhaust gas delivery module is transported to the exhaust gas treatment module for centralized treatment. The usage mode of the sealing device III is: when the hopper 12 needs to be used to receive sulfur, open the baffle 14 and push the hopper 12 to the load cell 15, and make the hopper 12 directly under the sulfur release pipe 16, and put the hopper 12 away. Afterwards, the opening 13 is blocked by the baffle 14, and the load cell 15 receives the weight signal of the hopper 12 and transmits the signal to the control system. The system also sends an instruction to open the automatic regulating valve I9 on the branch pipe 8 connected to the cover body 11, and the exhaust gas conveying module generates negative pressure to lead the volatile sulfur to the exhaust gas treatment module. When the weight of the receiving hopper 12 reaches the weight set by the load cell 15, the load cell 15 transmits a signal to the control system, and the control system sends an instruction to close the sulfur discharge solenoid valve 10 to stop the discharge of sulfur, and wait for the liquid sulfur to cool at an interval of 3-5 minutes After that, the control system sends an instruction to close the automatic regulating valve I9 on the branch pipe 8 connected to the cover body 11, and the interval time can be set by the control system.

As shown in FIG. 5 , the exhaust gas conveying module includes a fan connected to the main pipeline, and a check valve I arranged behind the fan along the conveying direction of the main pipeline. Check valve I is an automatic valve whose main function is to prevent the backflow of the medium. The fan can provide a negative pressure environment for the entire main pipeline, and introduce the exhaust gas discharged from each exhaust discharge point into the main pipeline.

The mixer is a tank structure, and a cavity is arranged inside the mixer, and the coke oven is a single-heat coke oven or a reheat coke oven. As shown in Figure 5, the general flue of each coke oven is connected to the input end of the mixer through a pipeline, and the pipeline connecting the general flue of the coke oven and the mixer is connected with a smoke induced fan and a gate valve. It is connected to the output terminal circuit of the control system. The mixer of each waste gas treatment unit is communicated with the main pipeline through a pipeline, and one of the pipelines connecting the mixer and the main pipeline is connected with an automatic regulating valve III and a pressure transmitter III, and the automatic regulating valve III and the control system output terminal circuit connection. Connect the manual regulating valve I and the pressure transmitter III to the other pipeline connecting the mixer and the main pipeline. The pressure transmitter III is connected to the input end of the control system in a circuit, and the automatic regulating valve III and the manual regulating valve I respectively control the cutoff, connection or switching of the fluids in the two pipelines. When the pipeline connecting the mixer and the main pipeline is cut off, the exhaust gas stops entering the mixer, the operator can choose to use two exhaust gas treatment units or use one of the exhaust gas by controlling the opening or closing of the automatic regulating valve III and manual regulating valve I processing unit.

A combustible gas analyzer is installed at the output end of each mixer. The combustible gas analyzer is connected to the input end of the control system. The combustible gas analyzer is used to detect the content of combustible gas in the gas output from the mixer. If it exceeds the normal range, the combustible gas analyzer transmits the signal to the control system, which is convenient for the operator to find it in time. The flue gas of the coke oven is led out by the induced smoke fan from the general flue of the coke oven, mixed with the VOCs from the main pipeline in the mixer, and the mixed gas output from the output end of the mixer enters the coke oven through the waste gas switch for combustion. , the structure of the exhaust gas shutter is known in the prior art and will not be repeated here.

The exhaust gas treatment principle of the exhaust gas treatment module is as follows: the maximum emission peak value of multiple exhaust gas discharge points conveyed from the main pipeline is 6000-6500Nm³/h, and the total coking organic waste gas of about 6000-6500Nm³/h is divided into two paths and enters into two channels respectively. Waste gas treatment unit, the coke oven treatment capacity of each waste gas treatment unit is 3000-3250 Nm³/h, the flue gas circulation volume of each coke oven is about 20,000 Nm³/h, and the coking organic waste gas of 3000-3250 Nm³/h is combined with 2 The coke oven flue gas of 10,000 Nm³/h is mixed in the mixer, and the coking organic waste gas out of the mixer is diluted to 1/7 of the original, and the content of this organic waste gas is already at an absolutely safe concentration. In addition, each coke oven needs to inhale 80,000 Nm³/h of combustion-supporting air during operation, so the concentration of VOCs has been diluted to 1/30 of the original concentration after entering each waste gas treatment unit, so it is absolutely safe. The diluted VOCs will not explode when passed into the coke oven for combustion.

Embodiment 2: The difference between Embodiment 2 and Embodiment 1 is that, as shown in FIG. 6 , the exhaust gas conveying module includes a fan connected to the main pipeline, and a check valve I is arranged behind the fan along the conveying direction of the main pipeline. And the quick cut-off valve I, the quick cut-off valve I is connected with the output end of the control system, and the quick cut-off valve I can control the cut-off, connection or switching of the fluid in the main pipeline by accepting the instructions sent by the control system. Check valve I is an automatic valve whose main function is to prevent the backflow of the medium. When the system is abnormal or the combustible components exceed the standard, in order to empty the exhaust gas in the main pipeline, the main pipeline located between the fan and the check valve I is connected to the chimney through a pipeline, and the pipeline is connected to the quick cut-off valve II. The valve II is electrically connected to the output terminal of the control system. When the quick shut-off valve I is closed and the quick shut-off valve II is opened, the exhaust gas in the main pipeline can be temporarily evacuated through the chimney.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (4)

1. The utility model provides a coke-oven plant VOCs processing system which characterized in that: comprises a control system, a combustion treatment system and a negative pressure recovery system;

the negative pressure recovery system comprises a plurality of waste gas discharge groups, each waste gas discharge group comprises a plurality of waste gas discharge points, and the pressure in each waste gas discharge point is kept in a range that a breather valve of each discharge point is not opened all the time;

the combustion treatment system comprises a waste gas acquisition module, a waste gas conveying module and a waste gas treatment module which are sequentially connected through a pipeline; the waste gas treatment module comprises two waste gas treatment units, each waste gas treatment unit comprises a mixer and a coke oven, waste gas conveyed by the waste gas conveying module is evenly distributed to the two waste gas treatment units, and the waste gas entering each waste gas treatment unit is mixed with flue gas from a coke oven main flue in the mixer and then enters the coke oven for combustion through a waste gas shutter;

the waste gas collection module comprises a plurality of types of waste gas discharge points, and the types of the waste gas discharge points comprise: a tar ammonia water clarifying tank, a desulfurization regeneration tower, a loading crane pipe, a sulfur melting kettle and a thiamine mother liquor overflow tank;

the system comprises a tar ammonia water clarifying tank, a main pipeline, a desulfurization regeneration tower, a thiamine mother liquor full-flow groove, a control system and a sulfur melting kettle, wherein sealing devices are arranged at a slag discharging port of the tar ammonia water clarifying tank, a discharging port of a loading crane pipe and a sulfur discharging pipe of the sulfur melting kettle, each sealing device is communicated with the main pipeline through a branch pipe, the discharging port of the desulfurization regeneration tower and the discharging port of the thiamine mother liquor full-flow groove are directly communicated with the main pipeline through branch pipes, the branch pipe connected with each waste gas discharging point is connected with an automatic regulating valve I and a pressure transmitter I, the pressure transmitter I;

the main flue of each coke oven is communicated with the input end of the mixer through a pipeline, a smoke-inducing fan and a gate valve are connected to the pipeline connecting the main flue of the coke oven and the mixer, and the smoke-inducing fan is connected with the output end circuit of the control system; the mixer of each waste gas treatment unit is communicated with the main pipeline through a pipeline;

each waste gas discharge group is communicated with a negative pressure gas pipeline (18) through a main pipeline (17), each main pipeline (17) is connected with an automatic regulating valve II (19) and a pressure transmitter II (20), the pressure transmitter II (20) is connected with an input end circuit of a control system, and the automatic regulating valve II (19) is connected with an output end circuit of the control system; the negative pressure gas pipeline (18) which is positioned behind the exhaust emission groups along the conveying direction of the negative pressure gas pipeline (18) is connected with a check valve II (21) and a quick cut-off valve IV (22), and the quick cut-off valve IV (22) is connected with an output end circuit of the control system;

each waste gas discharge group comprises a plurality of waste gas discharge points, the discharge outlet of each waste gas discharge point is communicated with a main pipeline (17) corresponding to the waste gas discharge group through a gas guide pipe (23), and each gas guide pipe (23) is connected with a manual regulating valve II (24);

the sealing device arranged at the slag discharging opening of the tar ammonia water clarifying tank comprises a sealing cover fixedly connected to the slag discharging opening of the tar ammonia water clarifying tank and a slag receiving hopper which is positioned below the sealing cover and is buckled with the sealing cover; the size of the lower opening of the sealing cover is matched with that of the upper opening of the slag receiving hopper, and the sealing cover is communicated with the main pipeline through a branch pipe;

the sealing device arranged at the discharge port of the loading crane pipe comprises a sealing plug sleeved at the discharge port of the loading crane pipe; a collecting cavity is arranged on the sealing plug; a guide outlet is arranged on the collection cavity; the outlet is communicated with the main pipeline through a branch pipe;

the sealing device arranged at the sulfur discharge pipe of the sulfur melting kettle comprises a cover body and a receiving hopper; one side of the cover body is provided with an opening communicated with the inside and the outside of the cover body, and a baffle capable of opening and closing the opening is arranged at the opening; a weighing sensor is arranged on the bottom surface inside the cover body; a sulfur discharge pipe with the tail end extending into the cover body is arranged above the weighing sensor; a sulfur discharge electromagnetic valve is arranged on the sulfur discharge pipe; the weighing sensor is connected with the input end circuit of the control system; the sulfur release electromagnetic valve is connected with an output end circuit of the control system; the cover body is communicated with the main pipeline through a branch pipe;

the waste gas conveying module comprises a fan connected to a main pipeline, a check valve I and a quick cut-off valve I, wherein the check valve I and the quick cut-off valve I are arranged behind the fan along the conveying direction of the main pipeline; be located and pass through the pipe connection chimney on the trunk line between fan and the check valve I, connect quick cut-off valve II on this pipeline, quick cut-off valve II and control system's output circuit connection.

2. A coke plant VOCs treatment system as recited in claim 1, wherein: the waste gas conveying module comprises a fan connected to a main pipeline, and a check valve I arranged behind the fan along the conveying direction of the main pipeline.

3. A coke plant VOCs treatment system as recited in claim 1, wherein: one of the pipelines connecting the mixer and the main pipeline is connected with an automatic regulating valve III and a pressure transmitter III, and the automatic regulating valve III is in circuit connection with the output end of the control system; the other pipeline connecting the mixer and the main pipeline is connected with a manual regulating valve I and a pressure transmitter III; and the pressure transmitter III is in circuit connection with the input end of the control system, the output end of each mixer is provided with a combustible gas analyzer, and the combustible gas analyzers are in circuit connection with the input end of the control system.

4. A coke plant VOCs treatment system as recited in claim 1, wherein: the exhaust emission points included in the plurality of exhaust emission groups are specifically: the reservoir area comprises a crude benzene storage tank, a tar storage tank and a low-level emptying groove; the blast cooling comprises a tar intermediate tank, a residual ammonia water tank, a circulating ammonia water tank, a low-level emptying tank, an initial cooling spraying tank, a light tar tank and a front water seal storage tank; the desulfurization comprises a liquid accumulation tank, a liquid storage tank, an accident tank, a desulfurization liquid circulation tank, a molten sulfur clear liquid storage tank, a foam tank, an auxiliary salt clear liquid tank and a pump room emptying tank; the ammonium sulfate comprises a mother liquor storage tank and a low-level emptying tank; the crude benzene and crude benzene intermediate tank, the lean oil tank, the emptying ground tank, the oil-water separator, the control separator and the crude benzene noncondenser, and the pressure of each exhaust emission point is controlled between-200 Pa to +200 Pa.

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