Gas purification control method and system

Abstract

The invention provides a coal gas purification control method and system, and the control method comprises the steps: closing a gas inlet valve and a gas outlet valve of a coal gas purification box body, opening a pressure release valve, and discharging gas in the coal gas purification box body; the gas inlet valve and the pressure release valve are closed, the exhaust valve is opened, and the gas purified by the gas purification box body is pumped into the gas purification box body through the back flushing mechanism, so that dust on the outer wall of the cloth bag in the gas purification box body falls off; and closing the blowback mechanism and the pressure release valve of the gas purification box body, and opening the gas inlet valve and the exhaust valve of the gas purification box body, so that the gas purification box body recovers normal work. When the outer wall of the cloth bag in the coal gas purification box body is dedusted, gas purified by the coal gas purification box body is blown back into the coal gas purification box body, and a pulse valve diaphragm is not required to be used for dedusting in a pulse manner, so that the consumption cost of the pulse valve diaphragm is saved; and the gas purified by the coal gas purification box body is adopted, so that nitrogen does not need to be additionally used, and the energy is saved.

Description

Technical Field

[0001] This invention relates to the field of electrical and automation control technology for gas purification, and in particular to a gas purification control method and system. Background Technology

[0002] The blast furnace gas purification and filtration system is the first dust removal device for the raw gas at the top of the blast furnace. Most of the dust and particulate matter in the gas falls into the dust bin at the bottom under its own gravity. After the dust and particulate matter are removed, the gas flows through the bag filter system for fine dust removal, resulting in clean gas. The dust and particulate matter that falls into the dust bin are discharged from the bottom.

[0003] The blast furnace gas purification and filtration system mainly adopts bag filtration. After a period of use, a lot of dust will accumulate on the outer wall of the bag. In order for the blast furnace gas purification and filtration system to work properly, it is necessary to collect the dust on the outer wall of the bag so that the bag can play its filtering role.

[0004] Existing methods for treating dust on the outer wall of filter bags mainly involve pulse jet cleaning into the filter bags. Pulse jet cleaning uses a short-duration high-pressure airflow (0.3–0.6 MPa) to instantly blow dust off the filter bags, quickly peeling off the dust layer on the surface of the filter bags. The dust falls into the dust collection bin, thus achieving dust collection from the filter bags.

[0005] Pulse jet cleaning typically uses pulse valve diaphragms for opening and closing. These diaphragms are wear parts, subject to high-frequency jet impact and aging, and usually need to be replaced every 6–12 months. Therefore, the consumption of pulse valve diaphragms is high, resulting in high costs. Secondly, the purification of coal gas uses nitrogen as the gas source, and the high-frequency daily jet cleaning consumes a lot of nitrogen, leading to significant energy waste. Summary of the Invention

[0006] This invention provides a method and system for controlling coal gas purification, so as to achieve the effects of saving costs and energy.

[0007] On one hand, the present invention provides a gas purification and control method, comprising:

[0008] Close the inlet and outlet valves of the gas purification chamber, open the pressure relief valve of the gas purification chamber, and discharge the gas inside the gas purification chamber. Close the inlet valve and pressure relief valve of the gas purification box, open the exhaust valve of the gas purification box, and draw the gas purified by the gas purification box into the gas purification box through the back-blowing mechanism, so that the dust on the outer wall of the cloth bag in the gas purification box falls off. Close the backflushing mechanism and the pressure relief valve of the gas purification box, open the air inlet valve and air outlet valve of the gas purification box, and the gas purification box will resume normal operation.

[0009] In one embodiment of the present invention, the backflush mechanism has backflush modes including timed backflush and differential pressure backflush.

[0010] In one embodiment of the present invention, the exhaust pipe of the gas purification box is connected to the main pipeline network, and multiple gas purification boxes are connected to the main pipeline network, and the multiple gas purification boxes are arranged in parallel. Each of the gas purification chambers is numbered, and each of the gas purification chambers is backflushed in sequence at regular intervals. The differential pressure inside each gas purification box is monitored. When the differential pressure inside the gas purification box is greater than the preset differential pressure, a differential pressure alarm is triggered, and the backflushing mechanism of the corresponding gas purification box is deactivated from timed backflushing and differential pressure backflushing is used. After the gas purification chamber finishes backflushing using the differential pressure backflushing mode, the gas purification chamber is at the end of the timed backflushing cycle.

[0011] In one embodiment of the present invention, when the pressure difference in multiple gas purification chambers is greater than the preset pressure difference, they are numbered according to the order of the pressure difference alarm, and pressure difference backflushing is performed in sequence until all gas purification chambers with pressure differences greater than the preset pressure difference are completed.

[0012] In one embodiment of the present invention, the backflush mode further includes manual backflush, and the response level of the manual backflush mode is higher than that of differential pressure backflush and timed backflush.

[0013] In one embodiment of the present invention, when the gas purification box is in a backflushing state, if the gas purification box triggers an abnormal alarm, the corresponding gas inlet valve, exhaust valve, and pressure relief valve of the gas purification box will enter manual control mode.

[0014] On the other hand, the present invention also provides a gas purification control system, wherein the gas purification control system employs the gas purification control method described above, and the gas purification control system includes: A gas purification chamber, which is used to purify coal gas, has an air inlet, an exhaust outlet and a pressure relief outlet; An air intake pipe is connected to the air intake port, and an air intake valve is connected to the air intake pipe. An exhaust pipe, one end of which is connected to the exhaust port, and the other end of which is away from the gas purification box is used to connect to the main pipeline network. An exhaust valve is connected to the exhaust pipe. A pressure relief pipe is provided for relieving pressure on the gas inside the gas purification box; the pressure relief pipe is connected to the pressure relief port and a pressure relief valve is connected to the pressure relief pipe. A backflushing mechanism, one end of which is connected to the exhaust pipe and the other end of which is connected to the main pipeline.

[0015] In one embodiment of the present invention, the end of the pressure relief pipe away from the gas purification box is connected to an ignition device for burning the residual gas.

[0016] In one embodiment of the present invention, a first pressure detection element is provided on the intake pipe, a second pressure detection element is provided on the exhaust pipe, and a third pressure detection element is provided on the pressure relief pipe.

[0017] In one embodiment of the present invention, the gas purification control system further includes a controller, which is used to control the backflushing mode of the backflushing mechanism.

[0018] The beneficial effects of this invention are as follows: The gas purification control method and system proposed in this invention remove dust from the outer wall of the filter bag inside the gas purification chamber by backflushing the purified gas into the gas purification chamber, eliminating the need for pulse valve diaphragms to remove dust via pulses, thus saving the consumption cost of pulse valve diaphragms; furthermore, this invention uses the purified gas from the gas purification chamber, eliminating the need for additional nitrogen, thus saving energy. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0020] In the attached diagram: Figure 1 This is a schematic diagram of the structure of a gas purification control system provided in an embodiment of the present invention.

[0021] The attached figures are labeled as follows: Gas purification box 1, air inlet pipe 2, air outlet pipe 3, pressure relief pipe 4, air inlet valve 5, air outlet valve 6, pressure relief valve 7, backflushing mechanism 8, first pressure detection element 9, second pressure detection element 10, third pressure detection element 11, ignition device 12. Detailed Implementation

[0022] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0023] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the shape, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0024] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0025] This invention provides a coal gas purification control method, which is applied to a coal gas purification control system. The coal gas purification control system includes a coal gas purification box 1, an inlet pipe 2, an exhaust pipe 3, a pressure relief pipe 4, and a backflushing mechanism 8.

[0026] The gas purification box 1 has an air inlet, an exhaust outlet, and a pressure relief port. An air inlet pipe 2 is installed at the air inlet, and an air inlet valve 5 is installed on the air inlet pipe 2. An exhaust outlet pipe 3 is installed at the exhaust outlet, and an exhaust valve 6 is installed on the exhaust outlet. A pressure relief pipe 4 is installed at the pressure relief port, and a pressure relief valve 7 is installed on the pressure relief pipe 4.

[0027] The coal gas purification and control method includes the following steps: S1. When the gas purification box 1 is in normal use, the inlet valve 5 and the exhaust valve 6 are in the open state, and the pressure relief valve 7 is in the closed state.

[0028] When it is necessary to remove dust from the filter bags inside the gas purification chamber 1, first close the inlet valve 5 and the exhaust valve 6, open the pressure relief valve 7, and discharge the gas inside the gas purification chamber 1. The pressure relief process needs to be continued until the pressure inside the gas purification chamber 1 drops to a level that is basically balanced with atmospheric pressure or drops to the safety threshold set by the system, so as to ensure that the inside of the gas purification chamber 1 is in a normal pressure or slightly negative pressure state, laying a safe foundation for subsequent backflushing.

[0029] S2. After confirming that the gas purification chamber 1 has been depressurized and is in a stable state, close the inlet valve 5 and the pressure relief valve 7 of the gas purification chamber 1 to re-seale the gas purification chamber 1. Next, open the exhaust valve 6 of the gas purification chamber 1 to achieve safe isolation between the gas purification chamber 1 and other equipment, preventing gas crossflow or backflow during subsequent operations. At this time, through the independent backflushing mechanism 8, the clean gas purified by the gas purification chamber 1 is injected into the gas purification chamber 1 from the exhaust pipe 3 in a reverse manner.

[0030] The airflow injected in reverse into the gas purification chamber 1 penetrates the filter bags, causing the dust layer that was originally adsorbed on the outer wall of the filter bags due to filtration to be subjected to severe impact and vibration, thereby effectively peeling off and shaking it off. The fallen dust falls into the dust bin at the bottom of the gas purification control system under the action of gravity. The backflushing cleaning process can restore the air permeability and filtration efficiency of the filter bags, ensuring the continuous and stable operation of the purification system.

[0031] This invention utilizes the clean gas produced by the system itself, purified by the gas purification chamber 1, as the gas source for backflushing and ash removal. Specifically, the backflushing mechanism 8 draws in and pressurizes the clean coal gas that has already been treated by the same purification system in this process flow, rather than the nitrogen or compressed air that often needs to be prepared and consumed separately in traditional methods. This completely eliminates the large amount of electrical energy consumed in preparing nitrogen or operating large air compressors, reducing the system's energy consumption at the source. It also eliminates the need to build and maintain an independent nitrogen preparation, storage, and supply system, saving on equipment investment, maintenance costs, and gas procurement costs.

[0032] Since the backflushing gas source itself is process gas, its composition, temperature and pressure are perfectly matched with the working conditions of the filter bag, avoiding the risks of condensation, dew or chemical reaction that may be caused by the introduction of external gases (such as humid air), which is more conducive to protecting the filter bag and extending its service life.

[0033] In some embodiments, the backflushing mechanism 8 is a backflushing fan, which re-introduces the gas discharged from the gas purification chamber 1 into the gas purification chamber 1.

[0034] S3. Close the backflushing mechanism 8 and the pressure relief valve 7 of the gas purification box 1, and open the air inlet valve 5 and the exhaust valve 6 of the gas purification box 1. The gas purification box 1 will then resume normal operation.

[0035] After the backflushing cleaning operation is completed, restore the normal filtration function of the gas purification chamber 1. First, shut down the backflushing mechanism 8 to cut off the reverse airflow. At the same time, ensure that the pressure relief valve 7 of the gas purification chamber 1 is in the fully closed state to maintain system sealing.

[0036] Subsequently, open the inlet valve 5 and the exhaust valve 6 of the gas purification chamber 1 in sequence. Typically, the inlet valve 5 can be opened slowly first to allow the raw gas to be purified to smoothly re-enter the gas purification chamber 1, filling the outer space of the filter bags. Then, the exhaust valve 6 is maintained or adjusted to its operating position. At this time, under the influence of the system pressure difference, the gas passes through the filter bags again. Dust in the gas is trapped on the outer wall of the filter bags, and the purified gas flows out through the exhaust valve 6 into the subsequent main pipeline.

[0037] In some embodiments, the backflushing mechanism 8 includes timed backflushing and differential pressure backflushing modes. In timed backflushing mode, the gas purification control system automatically initiates the backflushing procedure at preset fixed time intervals (e.g., every 4 or 6 hours). This mode, based on time-cumulative logic, periodically removes dust accumulated on the filter bags and is suitable for production environments with relatively stable dust loads and minimal fluctuations in operating conditions. Its advantages are simple and reliable control logic, but it lacks flexible response to actual filter bag blockage.

[0038] The differential pressure backflushing mode monitors the pressure difference (i.e., filter bag resistance) between the inlet and outlet sides of the gas purification chamber 1 in real time via a differential pressure transmitter. When the differential pressure rises and exceeds the preset upper threshold, it indicates that the dust layer on the outer wall of the filter bag has thickened to a certain extent, increasing the filtration resistance and reducing system efficiency. At this time, the gas purification control system automatically triggers the backflushing program to clean the corresponding gas purification chamber 1. After cleaning, the differential pressure decreases, and when it falls below the preset lower threshold, the backflushing automatically stops. The differential pressure backflushing mode achieves on-demand cleaning, effectively maintaining the gas purification control system within the optimal resistance range while minimizing unnecessary backflushing cycles, thus significantly saving backflushing air consumption, extending filter bag life, and reducing equipment mechanical wear.

[0039] In practical applications, the two backflush modes can be used in combination, or, depending on the level of intelligence of the process, the differential pressure backflush mode can be used as the main mode to achieve optimal operating economy and reliability.

[0040] For example, if the timed backflushing period is set to four hours, and the differential pressure in the gas purification chamber 1 remains below the preset upper limit of the differential pressure during these four hours, then the backflushing mechanism 8 will be activated to enable the timed backflushing mode after four hours have elapsed since the last backflushing. If, three hours after the last backflushing, the differential pressure in the gas purification control system is detected to exceed the preset upper limit of the differential pressure, then the backflushing mechanism 8 will be activated to enable the differential pressure backflushing mode.

[0041] In some embodiments, the entire gas purification control system includes multiple gas purification chambers 1, each of which has an exhaust pipe connected to a main pipeline network. The main pipeline network serves as the main pipeline for gas collection and transportation, collecting the purified gas from the multiple gas purification chambers 1. The multiple gas purification chambers 1 are arranged in parallel on the main pipeline network to improve the system's processing capacity and reliability through a parallel operating mode.

[0042] To facilitate management and orderly control, each gas purification chamber 1 is assigned a unique number, forming an equipment identification. The gas purification control system adopts a timed backflushing mechanism, that is, according to the number sequence, each gas purification chamber 1 is backflushed periodically to remove dust accumulated on the filter bags or filter elements and maintain their filtration efficiency.

[0043] During operation, the pressure difference (i.e., the gas pressure difference between the inlet and outlet) inside each gas purification chamber 1 is monitored in real time. When the pressure difference inside any gas purification chamber 1 exceeds the preset upper limit threshold, the gas purification control system immediately triggers a pressure difference alarm. At the same time, the backflushing mechanism 8 corresponding to the gas purification chamber 1 that exceeds the preset upper limit threshold will automatically exit the original timed backflushing sequence and switch to pressure difference backflushing mode, that is, timely and forced backflushing cleaning is performed according to the actual pressure difference, ensuring equipment safety and stable operation.

[0044] For example, a gas purification control system has 10 gas purification chambers 1, numbered 1, 2, ..., 10. At startup, each gas purification chamber 1 is backflushed every 4 hours in the order of their numbers (1-10). When gas purification chamber 5 is in timed backflushing mode, the next chamber to be backflushed should be gas purification chamber 6. If the system receives a pressure difference from gas purification chamber 8 that exceeds a preset upper limit threshold, then gas purification chamber 8 is moved before gas purification chamber 6. That is, after gas purification chamber 5 is backflushed, gas purification chamber 8 is backflushed, and then gas purification chamber 6 is backflushed.

[0045] When a gas purification chamber 1 is triggered by differential pressure and undergoes differential pressure backflushing, after the backflushing operation ends and the gas purification chamber 1 returns to normal operation, the backflushed gas purification chamber 1 will be reinstated into the timed backflushing cycle. However, its queue position for the next timed backflushing will be set to the end of the current cycle queue. This ensures that the abnormal gas purification chamber 1 is given priority while maintaining the overall order of the timed cycle, avoiding backflushing conflicts or uneven resource allocation. This mechanism realizes an efficient and flexible backflushing control strategy that combines timed maintenance with abnormal response.

[0046] As above, after the backflushing of gas purification box 1 (No. 5) is completed, gas purification box 1 (No. 8) is backflushed, and then gas purification box 1 (No. 6) is backflushed. The subsequent timing sequence is No. 6, No. 7, No. 9, No. 10, No. 1, No. 2... No. 5, No. 8, No. 6, and so on in a repeating cycle.

[0047] In some embodiments, when the pressure difference in multiple gas purification chambers 1 is greater than the preset pressure difference, the system will enter the multi-gas purification chamber 1 pressure difference backflushing coordination mode.

[0048] The system will trigger multiple differential pressure alarms simultaneously and assign differential pressure backflushing queue numbers to each gas purification chamber 1 according to the order in which the alarm signals are generated. The gas purification chamber 1 that alarms first will receive a priority number, and the gas purification chamber 1 that alarms later will be arranged in sequence to form the execution sequence for differential pressure backflushing.

[0049] Following this alarm sequence, the system sequentially performs differential pressure backflushing on each abnormal gas purification chamber 1. After the previous gas purification chamber 1 completes backflushing and exits the alarm state, the system automatically switches to the next gas purification chamber 1 in the queue, until all gas purification chambers 1 with excessive differential pressure have completed one round of differential pressure backflushing.

[0050] After all the gas purification chambers 1 with differential pressure alarms have been backflushed, the gas purification chambers 1 without alarms will be backflushed in sequence.

[0051] All gas purification units 1 that underwent differential pressure backflushing due to pressure differential anomalies will return to the scheduled backflushing cycle after completing their respective backflushing operations. Their position in the next scheduled backflushing queue will be arranged sequentially at the end of the scheduled cycle queue according to the order in which they completed differential pressure backflushing. This mechanism ensures both an orderly and timely system response in the event of sudden multi-equipment malfunctions and maintains the orderliness and fairness of the scheduled backflushing plan, thereby improving the overall stability and automation level of the system.

[0052] In some embodiments, in addition to the automatic modes of timed backflush and differential pressure backflush, the backflush control system also provides a manual backflush mode to provide manual intervention and emergency operation capabilities. The manual backflush mode has the highest response and execution priority, and its response level is higher than that of differential pressure backflush and timed backflush.

[0053] When an operator triggers a manual backflushing command on any gas purification chamber 1 through the control interface or on-site operation terminal, the system will respond to the command immediately, regardless of whether the gas purification chamber 1 being manually backflushed is currently in a timed backflushing waiting state or a differential pressure backflushing waiting state.

[0054] If the target gas purification chamber 1, which requires manual backflushing, is currently performing timed backflushing or differential pressure backflushing, manual backflushing will not be possible, and the target gas purification chamber 1 will continue to perform the current backflushing mode.

[0055] In some embodiments, when the gas purification chamber 1 is in the backflushing state, if the gas purification chamber 1 experiences an abnormal alarm, the corresponding gas purification chamber 1's inlet valve 5, exhaust valve 6, and pressure relief valve 7 will enter the manual control mode, and the gas purification chamber 1 will exit the timed backflushing and differential pressure backflushing queues.

[0056] In manual control mode, the original automatic backflushing (timed backflushing or differential pressure backflushing) process will be immediately suspended or terminated. The system will no longer automatically control the opening and closing of intake valve 5, exhaust valve 6 and pressure relief valve 7 according to the preset program, but will instead hand over control completely to the operator, who will make manual judgments and operations through the control panel, operator station or local cabinet.

[0057] While issuing an abnormal alarm, the system will clearly indicate the number of the gas purification box 1 that has been switched to manual control and its corresponding valve status on the operation interface, and provide necessary process parameter displays to assist personnel in decision-making.

[0058] Operators must manually operate the inlet valve 5, exhaust valve 6, and pressure relief valve 7 according to the alarm type, site conditions, and safety procedures to complete backflushing interruption, gas purification box 1 isolation, system pressure relief, gas replacement, or other emergency handling operations to ensure equipment and system safety.

[0059] After the cause of the abnormality has been investigated and eliminated, and the gas purification box 1 has returned to a safe and controllable state, the valve control authority can be restarted only after the operator confirms and performs the reset operation. The gas purification box 1 can then be reintroduced into the automatic backflushing cycle as needed.

[0060] Generally, abnormalities in the gas purification chamber 1 include abnormalities in the inlet valve 5, exhaust valve 6, and pressure relief valve 7, and the inability of the pressure inside the gas purification chamber 1 to reach the preset pressure relief pressure after pressure relief.

[0061] This invention relates to a backflushing control system for purified blast furnace gas. It is mainly used for backflushing control of purified blast furnace gas, which can effectively reduce the consumption of nitrogen in the backflushing of purified blast furnace gas. At the same time, it eliminates the need for conventional pulse valve diaphragms, which can effectively reduce the material cost of pulse valve diaphragms. It saves energy and reduces consumption while effectively reducing material and maintenance costs.

[0062] On the other hand, the present invention also provides a gas purification control system, which adopts the above-mentioned gas purification control method. The gas purification control system includes a gas purification chamber 1, an inlet pipe 2, an exhaust pipe 3, a pressure relief pipe 4, and a backflushing mechanism 8. The gas purification chamber 1 is used to purify gas and has an inlet, an exhaust port, and a pressure relief port.

[0063] The air inlet is connected to the air inlet pipe 2, which is the entrance for unpurified coal gas. One end of the air inlet pipe 2 is connected to the gas source, and the other end is connected to the air inlet. An air inlet valve 5 is connected to the air inlet pipe 2 to control the flow of coal gas into the coal gas purification box 1.

[0064] The exhaust port connects to exhaust pipe 3, which is the outlet for the purified gas; the pressure relief port connects to pressure relief pipe 4, used for pressure release in emergency or maintenance situations. One end of exhaust pipe 3 is connected to the exhaust port, and the other end of exhaust pipe 3, away from the gas purification box 1, is connected to the main pipeline network to realize the collection and transportation of purified gas. An exhaust valve 6 is installed on exhaust pipe 3 to control the passage of purified gas to the main pipeline network.

[0065] The pressure relief pipe 4 is connected to the pressure relief port of the gas purification box 1, and its end is usually led to a safe discharge point. The pressure relief pipe 4 is equipped with a pressure relief valve 7, which is opened when needed to safely release the gas in the gas purification box 1 to reduce the pressure.

[0066] The backflushing mechanism 8 is used to remove dust accumulated on the filter medium of the gas purification chamber 1 and restore the filtration capacity of the gas purification chamber 1. One end of the backflushing mechanism 8 is connected to the exhaust pipe 3, and the other end is connected to the main pipeline to obtain backflushing medium.

[0067] In some embodiments, the end of the pressure relief pipe 4 away from the gas purification chamber 1 is connected to an ignition device 12 for burning residual gas. When the pressure relief valve 7 is opened, the gas in the gas purification chamber 1 is discharged through the pressure relief pipe 4, and the ignition device 12 burns the gas to achieve harmless treatment.

[0068] In some embodiments, a first pressure detection element 9 is provided on the air inlet pipe 2. The first pressure detection element 9 monitors the pressure of the gas source entering the gas purification chamber 1 to ensure that the gas purification chamber 1 is within the allowable operating range of the equipment, preventing excessive pressure from damaging the filter bag or excessive pressure from affecting the filtration efficiency.

[0069] A second pressure detection element 10 is installed on the exhaust pipe 3. The second pressure detection element 10 is used to monitor the outlet pressure of the gas purification chamber 1. Monitoring the pressure of the filtered gas inside the gas purification chamber 1 through the second pressure detection element 10 is a key parameter reflecting the operating status of the gas purification chamber 1. The signal from the second pressure detection element 10 is combined with that from the first pressure detection element 9 to calculate the pressure difference between the inlet and outlet of the gas purification chamber 1 in real time.

[0070] A third pressure detection element 11 is installed on the pressure relief pipe 4. The third pressure detection element 11 is used to monitor the pressure of the pressure relief pipe 4.

[0071] In some embodiments, the gas purification control system further includes a controller, which controls the opening and closing of the inlet valve 5, the exhaust valve 6, and the pressure relief valve 7, the backflushing sequence of each gas purification chamber 1, and the backflushing mode of the backflushing mechanism 8. The controller typically employs a PLC, DCS, or a dedicated control cabinet. Based on process timing, logic, or alarm conditions, the controller automatically or remotely controls the opening and closing of the inlet valve 5, the exhaust valve 6, and the pressure relief valve 7. Simultaneously, the controller manages the backflushing sequence of multiple parallel gas purification chambers 1 according to a preset numbering sequence or optimization strategy, avoiding system pressure fluctuations caused by simultaneous backflushing. When controlling the backflushing mechanism 8, the controller can also switch between different backflushing modes, including timed backflushing (performed at a fixed cycle), differential pressure backflushing (automatically triggered based on chamber pressure differential), and manual backflushing (manually triggered in real-time), and can handle the priority and interlocking logic between modes.

[0072] This invention adds a backflushing mechanism 8, with one end connected to the main pipeline and the other end connected to the exhaust pipe 3. During normal use, the backflushing mechanism 8 is closed. When a gas purification chamber 1 needs backflushing, the corresponding inlet valve 5 and exhaust valve 6 are closed, and the pressure relief valve 7 is opened to relieve pressure in the gas purification chamber 1. Then, the pressure relief valve 7 and inlet valve 5 are closed, the exhaust valve 6 is opened, and the backflushing mechanism 8 is activated. The backflushing mechanism 8 draws the purified gas from the gas purification chamber 1 into the gas purification chamber 1 through the exhaust pipe 3, thus removing dust from the outer wall of the filter bags inside the gas purification chamber 1. After backflushing is complete, the inlet valve 5 is opened, and the unpurified gas enters the gas purification chamber 1, is purified, and then discharged into the main pipeline through the exhaust pipe 3.

[0073] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for controlling coal gas purification, characterized in that, include: Close the inlet and outlet valves of the gas purification chamber, open the pressure relief valve of the gas purification chamber, and discharge the gas inside the gas purification chamber. Close the inlet valve and pressure relief valve of the gas purification box, open the exhaust valve of the gas purification box, and draw the gas purified by the gas purification box into the gas purification box through the back-blowing mechanism, so that the dust on the outer wall of the cloth bag in the gas purification box falls off. Close the backflushing mechanism and the pressure relief valve of the gas purification box, open the air inlet valve and air outlet valve of the gas purification box, and the gas purification box will resume normal operation.

2. The gas purification and control method according to claim 1, characterized in that: The backflush mechanism includes timed backflush and differential pressure backflush modes.

3. The gas purification and control method according to claim 2, characterized in that: The exhaust pipe of the gas purification box is connected to the main pipeline network, and multiple gas purification boxes are connected to the main pipeline network, with the multiple gas purification boxes arranged in parallel. Each of the gas purification chambers is numbered, and each of the gas purification chambers is backflushed in sequence at regular intervals. The differential pressure inside each gas purification box is monitored. When the differential pressure inside the gas purification box is greater than the preset differential pressure, a differential pressure alarm is triggered, and the backflushing mechanism of the corresponding gas purification box is deactivated from timed backflushing and differential pressure backflushing is used. After the gas purification chamber finishes backflushing using the differential pressure backflushing mode, the gas purification chamber is at the end of the timed backflushing cycle.

4. The gas purification and control method according to claim 3, characterized in that: When the differential pressure in multiple gas purification chambers is greater than the preset differential pressure, they are numbered according to the order of differential pressure alarms, and differential pressure backflushing is performed in sequence until all gas purification chambers with differential pressure greater than the preset differential pressure are completed.

5. The gas purification and control method according to any one of claims 2-4, characterized in that: The backflush mode also includes manual backflush, which has a higher response level than differential pressure backflush and timed backflush.

6. The gas purification and control method according to claim 5, characterized in that: When the gas purification chamber is in the backflushing state, if the gas purification chamber alarms abnormally, the corresponding gas inlet valve, exhaust valve and pressure relief valve of the gas purification chamber will enter the manual control mode.

7. A gas purification control system, wherein the gas purification control system employs the gas purification control method according to any one of claims 1-6, characterized in that, The gas purification and control system includes: A gas purification chamber, which is used to purify coal gas, has an air inlet, an exhaust outlet and a pressure relief outlet; An air intake pipe is connected to the air intake port, and an air intake valve is connected to the air intake pipe. An exhaust pipe, one end of which is connected to the exhaust port, and the other end of which is away from the gas purification box is used to connect to the main pipeline network. An exhaust valve is connected to the exhaust pipe. A pressure relief pipe is provided for relieving pressure on the gas inside the gas purification box; the pressure relief pipe is connected to the pressure relief port and a pressure relief valve is connected to the pressure relief pipe. A backflushing mechanism, one end of which is connected to the exhaust pipe and the other end of which is connected to the main pipeline.

8. The gas purification control system according to claim 7, characterized in that: The end of the pressure relief pipe away from the gas purification box is connected to an ignition device for burning the residual gas.

9. The gas purification control system according to claim 7, characterized in that: A first pressure detection element is installed on the intake pipe, a second pressure detection element is installed on the exhaust pipe, and a third pressure detection element is installed on the pressure relief pipe.

10. The gas purification control system according to claim 7, characterized in that: The gas purification control system also includes a controller, which is used to control the backflushing mode of the backflushing mechanism.

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