A control method and system for feed production exhaust gas zero emission

Abstract

The application discloses a kind of control method and system for feed production exhaust gas zero emission, belong to feed production exhaust gas treatment technical field.Set in feed production system, including cooler, air pipe I, pulse dust collector air pipe II, heat exchanger and return air pipe, and also include controller, data acquisition unit and execution unit, controller is connected with man-machine interface by data input interface, controller is connected with data acquisition unit by data feedback interface, controller is connected with execution unit by data output interface.Based on feed exhaust gas zero emission treatment, through the organic combination of temperature sensor, dust detector, pressure sensor, temperature and humidity detector and so on in each section of system, system operation data is presented in real time, abnormal condition alarm is realized, and through variable frequency control of induced draft fan, water pump and the like, system control and management are realized.

Description

Technical Field

[0001] This invention relates to a control method and system, and more particularly to a control method and system for zero emissions of waste gas from feed production, belonging to the field of waste gas treatment technology in feed production. Background Technology

[0002] Currently, various industries face a severe environmental situation and significant pressure for environmental governance. As emission standards for odorous pollutants become increasingly stringent, environmental problems in these industries will become even more prominent. During feed production, the resulting exhaust gases are characterized by high temperature, high humidity, high dust levels, odor, and large air volume (e.g., the exhaust temperature for drying and cooling is typically 65-75℃, relative humidity 55-70%, and dust concentration 30-50 mg / Nm³). 3 The odor is dimensionless (above 5000), and water molecules, as an important carrier of odor components, must be treated. In addition, the various deodorization equipment involved has high requirements for the moisture content of the exhaust gas and has conditional restrictions on the moisture content of the inlet air.

[0003] In the feed industry, waste gas treatment has always been a technical challenge. Traditional feed production waste gas treatment is merely a purely end-of-pipe approach: waste gas generated in the production stage → treated by environmental protection equipment → discharged. This end-of-pipe treatment process is costly, has low stability, and cannot meet emission requirements under adverse weather conditions, thus failing to integrate with the production process. However, in actual feed production, major equipment such as dryers, coolers, and grinders require significant amounts of supplemental air. Therefore, a shift from the traditional end-of-pipe treatment approach is needed to organically link waste gas treatment with the feed production process, thereby completely resolving the waste gas emission problem.

[0004] Existing technologies CN113082881A and CN214680648U, combined with the actual situation of the extruded or granulated feed preparation process, control the process from the source of production. The waste gas generated in each stage of feed production and processing is dust-reduced, heat-exchanged, and pressure-equalized before being reused in each stage. This recycling of waste gas from the production process completely solves the problems of dust, odor, and high temperature, and effectively achieves zero emissions. Specifically, the disclosed pulse dust collector is equipped with dust concentration and pressure sensors, but these are only used to monitor the dust removal effect and pressure difference to ensure the stability and safety of the waste gas treatment process. The return air duct is equipped with wind speed and wind pressure sensors, but these only monitor wind speed and wind pressure in real time to ensure the stability and safety of the reuse of treated waste gas.

[0005] CN214972515U discloses a "waste gas recovery system for feed production," applicable to the recovery and utilization of waste gas in feed production. It can recycle all exhaust gas, thereby completely solving the problem of odorous waste gas and effectively achieving zero emissions. Specifically, it discloses the configuration of several safety detection devices, including: several temperature and humidity sensors installed at the air inlet of the cooler; a pressure sensor I and an alarm installed on the housing of the pulse dust collector; a temperature and humidity sensor I and a dust sensor I installed on the pipeline at the air inlet of the pulse dust collector; a dust sensor II and a temperature and humidity sensor II installed at the air outlet of the heat exchanger; and a pressure sensor II installed on the inner wall of the pressure equalization and speed reduction box.

[0006] CN216259628U discloses a "Pulse Jet Dust Collector Bag Dust Detection System," which includes a tube sheet, a display screen, a controller, and several sets of bag assemblies. By installing dust probes corresponding to each bag at the venturi tube opening at the bag outlet, it can quickly identify damaged bags once the dust concentration in the air flowing out of the bag outlet exceeds a set value, allowing for targeted repair or replacement. This fully ensures dust removal production efficiency and effectively avoids the adverse effects of bag damage on emission quality. CN109126314A discloses a "Fault Diagnosis System for Online Cleaning Pulse Jet Dust Collector Cleaning System," which includes: multiple pressure sensors installed at the air tank inlet, the pulse cleaning compressed air main pipe, and the air distribution manifold of each bag chamber; a controller connected to each pressure sensor for receiving first data from the pressure sensors, comparing the first data with pre-stored second data, and outputting a judgment result; a power supply electrically connected to each pressure sensor and the controller; and a display device for receiving and displaying the judgment result output by the controller.

[0007] Although existing technologies have emerged that shift the focus from traditional end-of-pipe treatment to organically link waste gas treatment with the feed production process and completely solve the waste gas emission problem, there is still a lack of corresponding automated control technologies as feed production waste gas zero-emission treatment technologies develop and improve. Summary of the Invention

[0008] This invention proposes a control method and system for zero-emission treatment of feed production waste gas, based on existing zero-emission treatment methods. In this technical solution, building upon zero-emission treatment of feed waste gas, the system utilizes a combination of temperature sensors, dust detectors, pressure sensors, and temperature and humidity detectors in various stages to display real-time system operation data, trigger alarms for abnormal conditions, and achieve system control and management through frequency conversion control of the induced draft fan, water pump, and other components.

[0009] To achieve the above technical objectives, the following technical solution is proposed:

[0010] A control system for zero emissions of waste gas from feed production is installed in the feed production system. The control system includes a cooler, a pulse dust collector, and a heat exchanger. The cooler inlet is connected to the feed production system. The cooler outlet is connected to the pulse dust collector inlet via duct I. The pulse dust collector outlet is connected to the heat exchanger inlet via duct II. The heat exchanger outlet is connected to the cooler return air outlet via a return air duct. The cooler, pulse dust collector, and heat exchanger form a waste gas recycling and reuse loop, recycling the waste gas from the feed production process, thereby completely solving the odor problem and effectively achieving zero emissions of waste gas.

[0011] Among them, the air duct I, pulse dust collector, air duct II and heat exchanger are all covered with insulation layer;

[0012] The chilled water outlet of the heat exchanger is connected to the chilled water tank through chilled water return pipe I, and the chilled water tank is connected to the chilled water inlet of the heat exchanger through chilled water supply pipe I. An external circulation path for chilled water recycling and reuse is formed between the heat exchanger, chilled water return pipe I, chilled water tank and chilled water supply pipe I.

[0013] The control system further includes a controller, a data acquisition unit, and an execution unit. The controller is connected to a human-machine interface via a data input interface, connected to the data acquisition unit via a data feedback interface, and connected to the execution unit via a data output interface.

[0014] Controller: Includes temperature control module, air pressure control module, alarm module and pulse control module;

[0015] Data acquisition unit: Includes a sensor group for data acquisition and transmission in the zero-emission treatment process of feed production exhaust gas. The sensor group includes temperature sensor I installed in the cooler, dust detector I and temperature and humidity detector I installed on duct I, wind pressure sensor I installed on the pulse dust collector, dust detector II, temperature and humidity detector II and wind pressure sensor II installed on duct II, and temperature and humidity detector III and wind pressure sensor III installed on the return air duct. Temperature sensor I, dust detector I, temperature and humidity detector I, wind pressure sensor I, dust detector II, temperature and humidity detector II, wind pressure sensor II, temperature and humidity detector III and wind pressure sensor III are all connected to the controller via electrical signals.

[0016] The execution unit includes a group of devices for executing controller commands in the zero-emission treatment process for feed production exhaust gas. The group of devices includes an external circulation pump installed on the chilled water supply pipe, a variable frequency induced draft fan installed on the return air duct, an alarm and a fault light, and an electromagnetic pulse valve installed on the pulse dust collector blowpipe. The temperature control module is connected to the external circulation pump via an electrical signal, the air pressure control module is connected to the variable frequency induced draft fan via an electrical signal, the alarm module is connected to the alarm and fault light via an electrical signal, and the pulse control module is connected to the electromagnetic pulse valve via an electrical signal.

[0017] The controller receives temperature, dust concentration, humidity, and wind pressure setpoints from the human-machine interface, and also receives temperature, dust, humidity, and wind pressure detection information from the data acquisition unit, performing information analysis, numerical comparison, and judgment. It receives setting instructions through the human-machine interface, issues instructions through the execution unit, and issues data acquisition instructions through the data acquisition unit.

[0018] Human-Machine Interface (HMI): Enables input of temperature, dust concentration, humidity, and wind pressure settings. The HMI layout can include icons for a multi-function meter, external circulation pump operation, external circulation pump stop, variable frequency induced draft fan operation, variable frequency induced draft fan stop, alarm operation, alarm stop, fault light operation, and fault light stop.

[0019] Data acquisition unit: Receives data acquisition instructions from the controller and completes the acquisition and transmission of temperature detection information, dust concentration detection information, humidity detection information and wind pressure detection information during the zero-emission treatment of feed production exhaust gas, i.e., feeds it back to the controller;

[0020] Execution unit: Completes the instructions issued by the controller.

[0021] Preferably, the controller and human-machine interface are both located on the PLC control cabinet in the central control room, and the alarm and fault light are also located on the control cabinet. The set parameters are set into the PLC system through the human-machine interface. Based on the comprehensive feedback data, the variable frequency induced draft fan and the external circulation pump are automatically controlled. Furthermore, the sensor group set in each section of the zero-emission system realizes real-time data display and alarm for abnormal conditions, which facilitates system control and management.

[0022] Preferably, there are four temperature sensors I, evenly distributed inside the cooler, to ensure effective and accurate acquisition of the temperature inside the cooler, thereby providing accurate data feedback to the controller and facilitating the stability of the control system.

[0023] Preferably, the dust detector I and the temperature and humidity detector I are located in section I of the air duct near the air outlet of the cooler.

[0024] Preferably, the temperature and humidity detector III is located in the return air duct section near the heat exchanger.

[0025] Preferably, the wind pressure sensor III is located in the return air duct section near the variable frequency induced draft fan.

[0026] Preferably, the heat exchanger is connected to a condensate collection tank via a condenser pipe to discharge and collect the condensate formed due to heat exchange of waste gas, thereby ensuring the normal operation of the heat exchanger and indirectly ensuring the stability of the zero-emission treatment process for waste gas from feed production.

[0027] Preferably, the outlet of the chilled water tank is connected to the return water port of the refrigeration unit in the feed production line through the chilled water return pipe II, and the outlet of the refrigeration unit in the feed production line is connected to the inlet of the chilled water tank through the chilled water supply pipe II. An internal circulation path for chilled water recycling and reuse is formed between the chilled water tank, the chilled water return pipe II, the refrigeration unit and the chilled water supply pipe II, providing low-temperature chilled water to cool the high-temperature exhaust gas, thereby improving the working efficiency and quality of the heat exchanger;

[0028] An internal circulation pump is installed on chilled water return pipe II, and the temperature control module is also connected to the internal circulation pump via an electrical signal.

[0029] Preferably, the chilled water tank is provided with an overflow port and a water inlet at the top, and a drain port at the bottom. This arrangement ensures that the chilled water tank stably and orderly supplies chilled water to the heat exchanger, and collects the chilled water discharged from the heat exchanger, thereby indirectly ensuring the controllability and stability of this control system.

[0030] A method for controlling zero emissions of waste gas from feed production specifically includes the following steps:

[0031] A. The return air obtained from the zero-emission treatment system for feed production exhaust gas is introduced into the cooler. Temperature sensor I detects the temperature inside the cooler and transmits the temperature signal to the controller. When the temperature is higher or lower than the set value of 20-35℃, the temperature control module sends a command to the external circulation pump to increase or decrease the temperature, thereby controlling the temperature in the cooler within the set temperature range. Alternatively, the alarm module sends a command to the alarm device, and the alarm module sends a command to the fault light to flash. In such cases, further inspection by the staff is required.

[0032] If the return air temperature in the cooler is too low, the large temperature difference between the return air and the material will cause condensation, affecting product quality. If the return air temperature is too high, the material cannot be cooled in time, resulting in high material temperature, easy clumping, mold growth, and spoilage. The operating frequency of the external circulation pump is adjusted by using the return air temperature detected by a temperature sensor to meet the minimum operating frequency required for cooling, thereby achieving energy saving.

[0033] B. Dust detector I detects the dust concentration in duct I and transmits the dust concentration signal to the controller. When the dust concentration is higher than 300mg / L, the alarm module sends an alarm command to the alarm device and sends a flashing command to the fault light. Further inspection by the staff is required.

[0034] The quality of the feed is judged by the dust concentration detected by dust detector I. When the concentration is higher than 300 mg / L, the feed has a high dust content and poor quality, and needs to be reworked.

[0035] C. Temperature and humidity detector I detects the temperature and relative humidity inside duct I, and temperature and humidity detector II detects the temperature and relative humidity inside duct II. The detector transmits the corresponding temperature and humidity signals to the controller. When the difference between the temperature detected by temperature and humidity detector I and the temperature detected by temperature and humidity detector II exceeds 15°C, and / or the difference between the relative humidity detected by temperature and humidity detector I and the relative humidity detected by temperature and humidity detector II exceeds 10%, the alarm module sends an alarm command to the alarm device. Additionally, the alarm module sends a flashing command to the fault indicator light, requiring further inspection by the personnel.

[0036] The temperature difference and relative humidity between temperature and humidity detectors I and II are used to determine the sealing and operational status of duct I, duct II, and the pulse dust collector. If the difference between the temperature detected by temperature and humidity detector I and the temperature detected by temperature and humidity detector II exceeds 15°C, the insulation layers of duct I and the pulse dust collector may be damaged, air leakage may occur between duct I and the pulse dust collector, and the filter bags inside the pulse dust collector may become clogged with condensate.

[0037] D. Dust detector II detects the dust concentration inside the pulse dust collector and transmits the dust concentration signal to the controller. When the dust concentration is higher than 300mg / L, the alarm module sends an alarm command to the alarm device and sends a flashing command to the fault light. Further inspection by the staff is required.

[0038] The dust concentration detected by dust detector I and dust detector II determines whether the pulse dust collector is operating normally. When the concentration is higher than 300mg / L, the filter bags may fall off or break inside the pulse dust collector, and the machine needs to be stopped to check the filter bags.

[0039] E. Temperature and humidity detector III detects the temperature and relative humidity inside the return air duct and transmits the corresponding temperature and humidity signals to the controller. When the temperature is greater than 35°C and / or the relative humidity is greater than 90%, the alarm module sends an alarm command to the alarm device and sends a flashing command to the fault light. Further inspection by the staff is required.

[0040] The working efficiency and operating status of the heat exchanger are determined using temperature and humidity detectors II and III. When the temperature measured by temperature and humidity detector III is higher than 35℃, it indicates that the refrigeration system of the heat exchanger has failed, and it is necessary to focus on checking whether the pipe valves in the refrigeration system are open properly and whether the external circulation pump of the refrigeration system is damaged.

[0041] F. Wind pressure sensor I detects the wind pressure in duct II and transmits the corresponding wind pressure signal to the controller; wind pressure sensor II detects the wind pressure in the pulse dust collector and transmits the corresponding wind pressure signal to the controller. When the wind pressure difference between the two locations is greater than 3500Pa, the alarm module sends an alarm command to the alarm device and sends a flashing command to the fault light. Further inspection by the staff is required.

[0042] The operation of the pulse dust collector is determined by wind pressure sensor I and wind pressure sensor II. If the wind pressure difference is greater than 3500Pa, the pulse dust collector has high pressure loss and high resistance, and it is necessary to check for condensation, bag clogging, or other issues.

[0043] G. The blowing pressure of the pulse dust collector's blow pipe is controlled by an electromagnetic pulse valve to ensure it is not lower than the set value;

[0044] The pulse-jet cleaning system can employ three methods: timed, pressure-controlled, and manual cleaning. For example, the cleaning interval can be set to 15 seconds, the inlet and outlet pressure difference to be 2500 Pa, and pressure-controlled cleaning can be prioritized. The dust collector control system monitors operating parameters such as cleaning, inlet flue gas temperature and humidity, and cleaning pressure in real time. The control interface is integrated into the zero-emission system terminal, displaying the process and sensor values ​​via a human-machine interface, enabling dual control from the work site and the central control room.

[0045] H. The wind pressure sensor III detects the wind pressure in the return air duct and transmits the wind pressure signal to the controller. When the wind pressure is higher or lower than the set value of -5 to -30 Pa, the wind pressure control module sends a command to the variable frequency induced draft fan to ensure that the wind pressure in the section of the return air duct near the cooler is within the set wind pressure range; or, the alarm module sends an alarm command to the alarm device, and the alarm module sends a flashing command to the fault light, in which case further inspection by the staff is required.

[0046] Among them, the wind pressure sensor III is used to determine whether the entire return air duct is normal, and the return air duct at the front end of the variable frequency induced draft fan achieves a slight negative pressure (-5 to -30Pa), which is achieved through the variable frequency control of the variable frequency induced draft fan.

[0047] The positional relationships involved in this technical solution, such as "between," "inner," and "above," are defined based on the actual usage conditions and are common terms in this technical field, as well as common terms used by those skilled in the art in actual use.

[0048] The beneficial technical effects of adopting this technical solution are as follows:

[0049] In this invention, the zero-emission control system and corresponding control method for feed production waste gas are set up to achieve automation of zero-emission treatment of feed production waste gas. All the treatment processes involved are completed independently by the control system, reducing the intensity of manual management and labor, and ensuring the stability, controllability and traceability of each process and corresponding equipment in the zero-emission treatment of feed production waste gas. At the same time, the feed production waste gas is effectively treated to achieve waste gas recycling and reduce environmental pressure.

[0050] This invention effectively treats waste gas from feed production to achieve zero emissions. For example, the waste gas treated by the heat exchanger is eventually returned to the cooler by the action of a variable frequency fan.

[0051] Furthermore, this invention ensures the effective operation of the zero-emission system. If any abnormality occurs, it provides timely feedback and handling, reducing the system failure rate and operating energy consumption, thus providing a better prerequisite for the stable production of feed. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of the structure of the present invention;

[0053] Figure 2 This is a schematic diagram (a) of the logic connection of the control system in this invention;

[0054] Figure 3 This is a schematic diagram (II) of the logic connection of the control system in this invention;

[0055] Figure 4 This is a partial circuit example diagram (I) involved in the present invention;

[0056] Figure 5 This is a partial circuit example diagram (II) involved in the present invention;

[0057] Figure 6 This is a partial circuit example diagram (III) involved in the present invention.

[0058] Figure 7 This is a schematic diagram of the PLC control cabinet structure involved in the present invention;

[0059] Figure 8 This is a diagram showing the human-machine interface during the operation of the present invention.

[0060] In the diagram, 1. Cooler, 2. Pulse dust collector, 3. Heat exchanger, 4. Duct I, 5. Duct II, 6. Return air duct, 7. Chilled water return pipe I, 8. Chilled water tank, 81. Overflow port, 82. Water inlet, 83. Sewage outlet, 9. Chilled water supply pipe I.

[0061] 10. Controller; 11. Data acquisition unit; 12. Execution unit; 13. Human-machine interface;

[0062] 14. Temperature control module; 15. Air pressure control module; 16. Alarm module;

[0063] 17. Temperature sensor I; 18. Dust detector I; 19. Temperature and humidity detector I; 20. Wind pressure sensor I; 21. Dust detector II; 22. Temperature and humidity detector II; 23. Wind pressure sensor II; 24. Temperature and humidity detector III; 25. Wind pressure sensor III.

[0064] 26. External circulation pump; 27. Variable frequency induced draft fan; 28. Alarm; 29. ​​Fault indicator light;

[0065] 30. Condensate coil; 31. Condensate collection tank; 32. Chilled water return pipe II; 33. Refrigeration unit; 34. Chilled water supply pipe II; 35. Internal circulation pump; 36. Electromagnetic pulse valve; 37. Pulse control module. Detailed Implementation

[0066] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0067] In the following embodiments, the devices and models involved are as follows:

[0068]

[0069] Example 1

[0070] Based on the existing zero-emission treatment of feed waste gas, this embodiment proposes a control system for zero-emission feed production waste gas. On the basis of zero-emission treatment of feed waste gas, the system integrates temperature sensors, dust detectors, pressure sensors, temperature and humidity detectors in each section to present system operation data in real time, realize alarms for abnormal conditions, and realize system control and management through frequency conversion control of induced draft fans, water pumps, etc.

[0071] like Figure 1 As shown, specifically, the control system is installed in the feed production system. The control system includes a cooler 1, a pulse dust collector 2, and a heat exchanger 3. The feed inlet of the cooler 1 is connected to the feed production system. The air outlet of the cooler 1 is connected to the air inlet of the pulse dust collector 2 through a duct I 4. The air outlet of the pulse dust collector 2 is connected to the air inlet of the heat exchanger 3 through a duct II 5. The air outlet of the heat exchanger 3 is connected to the return air outlet of the cooler 1 through a return air duct 6. The cooler 1, the pulse dust collector 2, and the heat exchanger 3 form a waste gas recycling and reuse loop, recycling the waste gas in the feed production process, thereby completely solving the odor waste gas problem and effectively achieving zero waste gas emissions.

[0072] Among them, the air duct I4, pulse dust collector 2, air duct II5 and heat exchanger 3 are all equipped with insulation layers;

[0073] The chilled water outlet of heat exchanger 3 is connected to chilled water tank 8 through chilled water return pipe I7, and chilled water tank 8 is connected to chilled water inlet of heat exchanger 3 through chilled water supply pipe I9. A chilled water recycling and reuse external circulation path is formed between heat exchanger 3, chilled water return pipe I7, chilled water tank 8 and chilled water supply pipe I9.

[0074] like Figure 2-3 As shown, the control system further includes a controller 10, a data acquisition unit 11, and an execution unit 12. The controller 10 is connected to the human-machine interface 13 via a data input interface, the controller 10 is connected to the data acquisition unit 11 via a data feedback interface, and the controller 10 is connected to the execution unit 12 via a data output interface; wherein,

[0075] like Figure 4-6 As shown, the controller 10 includes a temperature control module 14, a wind pressure control module 15, an alarm module 16, and a pulse control module 37.

[0076] Data acquisition unit 11: includes a sensor group for collecting and transmitting feedback data in the zero-emission treatment process of feed production exhaust gas. The sensor group includes a temperature sensor I17 installed in the cooler 1, a dust detector I18 and a temperature and humidity detector I19 installed on the air duct I4, a wind pressure sensor I20 installed on the pulse dust collector 2, a dust detector II21, a temperature and humidity detector II22 and a wind pressure sensor II23 installed on the air duct II5, and a temperature and humidity detector III24 and a wind pressure sensor III25 installed on the return air duct 6. Temperature sensor I17, dust detector I18, temperature and humidity detector I19, wind pressure sensor I20, dust detector II21, temperature and humidity detector II22, wind pressure sensor II23, temperature and humidity detector III24 and wind pressure sensor III25 are all connected to the controller 10 via electrical signals.

[0077] Execution unit 12: includes a group of devices for executing commands from controller 10 in the zero-emission treatment process for feed production exhaust gas. The group of devices includes an external circulation pump 26 installed on the chilled water supply pipe 9, a variable frequency induced draft fan 27 installed on the return air duct 6, an alarm 28 and a fault light 29, and an electromagnetic pulse valve 36 installed on the blow pipe of the pulse dust collector 2. The temperature control module 14 is connected to the external circulation pump 26 via an electrical signal, the air pressure control module 15 is connected to the variable frequency induced draft fan 27 via an electrical signal, the alarm module 16 is connected to the alarm 28 and the fault light 29 via an electrical signal, and the pulse control module 37 is connected to the electromagnetic pulse valve 36 via an electrical signal.

[0078] The controller 10 receives temperature, dust concentration, humidity, and wind pressure setpoints from the human-machine interface 13, and also receives temperature, dust, humidity, and wind pressure detection information from the data acquisition unit 11, performing information analysis, numerical comparison, and judgment. It receives setting instructions through the human-machine interface 13, issues instructions through the execution unit 12, and issues data acquisition instructions through the data acquisition unit 11.

[0079] Human-Machine Interface 13: This interface allows for the input of temperature, dust concentration, humidity, and wind pressure settings. The layout of the human-machine interface 13 can include icons for a multi-function meter, an external circulation pump 26 (operating and stopping), a variable frequency induced draft fan 27 (operating and stopping), an alarm 28 (operating and stopping), and a fault light 29 (operating and stopping). Figure 8 (as shown)

[0080] Data acquisition unit 11: Receives data acquisition instructions from controller 10, completes the acquisition and transmission of temperature detection information, dust concentration detection information, humidity detection information and wind pressure detection information during the zero-emission treatment of feed production exhaust gas, and feeds it back to controller 10;

[0081] Execution unit 12: Completes the instructions issued by controller 10.

[0082] The number of temperature sensor I17, dust detector I18, temperature and humidity detector I19, wind pressure sensor I20, dust detector II21, temperature and humidity detector II22, wind pressure sensor II23, temperature and humidity detector III24, and wind pressure sensor III25 can be further limited according to actual needs.

[0083] Example 2

[0084] Based on Embodiment 1, this embodiment further limits the arrangement of the controller 10 and the human-machine interface 13 to further illustrate the technical solution.

[0085] Both the controller 10 and the human-machine interface 13 are located on the PLC control cabinet in the central control room (e.g., Figure 7 As shown), alarm 28 and fault light 29 are both installed on the control cabinet. The set parameters are set into the PLC system through human-machine interface 13. Based on the comprehensive feedback data, the variable frequency induced draft fan 27 and external circulation pump 26 are automatically controlled. In addition, through the sensor group set in each section of the zero emission system, the data is presented in real time and the alarm for abnormal conditions is realized, which facilitates system control and management.

[0086] Example 3

[0087] Based on Examples 1-2, this example further specifies the arrangement of temperature sensor I17, dust detector I18, temperature and humidity detector I19, temperature and humidity detector III24, and wind pressure sensor III25 to further illustrate this technical solution.

[0088] There are four temperature sensors I17, which are evenly distributed inside the cooler 1 to ensure that the temperature inside the cooler 1 is effectively and accurately collected, thereby providing accurate data feedback to the controller 10 and facilitating the stability of the control system.

[0089] Dust detector I18 and temperature and humidity detector I19 are installed at section I4 of the air duct near the air outlet of cooler 1.

[0090] Temperature and humidity detector Ⅲ24 is located at section 6 of the return air duct near heat exchanger 3.

[0091] The wind pressure sensor Ⅲ25 is located at section 6 of the return air duct near the variable frequency induced draft fan 27.

[0092] Example 4

[0093] Based on embodiments 1-3, this embodiment further defines the heat exchanger 3 to further illustrate the technical solution.

[0094] The heat exchanger 3 is connected to a condensate collection box 31 via a condenser pipe 30, which discharges and collects the condensate formed due to the heat exchange of waste gas, thereby ensuring the normal operation of the heat exchanger 3 and indirectly ensuring the stability of the zero-emission treatment process for waste gas from feed production.

[0095] Among them, the outlet of the chilled water tank 8 is connected to the return water port of the refrigeration unit 33 in the feed production line through the chilled water return pipe II 32, and the outlet of the refrigeration unit 33 in the feed production line is connected to the inlet of the chilled water tank 8 through the chilled water supply pipe II 34. The chilled water tank 8, the chilled water return pipe II 32, the refrigeration unit 33 and the chilled water supply pipe II 34 form an internal circulation path for chilled water recycling and reuse, providing low-temperature chilled water to cool the high-temperature exhaust gas, thereby improving the working efficiency and quality of the heat exchanger 3;

[0096] An internal circulation pump 35 is installed on the chilled water return pipe II 32, and the temperature control module 14 is also connected to the internal circulation pump 35 via an electrical signal.

[0097] In addition, the chilled water tank 8 is provided with an overflow port 81 and a water inlet 82 at the top, and a drain port 83 at the bottom. This arrangement ensures that the chilled water tank 8 supplies chilled water to the heat exchanger 3 stably and orderly, and collects the chilled water discharged by the heat exchanger 3, thereby indirectly ensuring the controllability and stability of this control system.

[0098] Example 5

[0099] This embodiment proposes a control method for zero emissions of waste gas from feed production.

[0100] Specifically, the steps include the following:

[0101] A. The return air obtained from the zero-emission treatment system for feed production exhaust gas is introduced into the cooler 1. Temperature sensor I 17 detects the temperature inside the cooler 1 and transmits the temperature signal to the controller 10. When the temperature is higher or lower than the set value of 20-35℃, the temperature control module 14 sends a command to the external circulation pump 26 to increase or decrease the temperature, thereby controlling the temperature in the cooler 1 within the set temperature range; or, the alarm module 16 sends an alarm command to the alarm 28, and the alarm module 16 sends a flashing command to the fault light 29, in which case further inspection by the staff is required.

[0102] If the return air temperature in cooler 1 is too low, the large temperature difference between the return air and the material will cause condensation, affecting product quality. If the return air temperature is too high, the material cannot be cooled in time, resulting in high material temperature, easy clumping, mold growth, and spoilage. The operating frequency of the external circulation pump 26 is adjusted by detecting the return air temperature through a temperature sensor to meet the minimum operating frequency required for cooling, thereby achieving energy saving.

[0103] B. Dust detector I18 detects the dust concentration in duct I4 and transmits the dust concentration signal to controller 10. When the dust concentration is higher than 300mg / L, alarm module 16 sends an alarm command to alarm 28 and alarm module 16 sends a flashing command to fault light 29, which requires further inspection by staff.

[0104] The quality of the feed is judged by the dust concentration detected by dust detector I18. When the concentration is higher than 300 mg / L, the feed has a high dust content and poor quality, and needs to be reworked.

[0105] C. Temperature and humidity detector I19 detects the temperature and relative humidity inside air duct I4, and temperature and humidity detector II22 detects the temperature and relative humidity inside air duct II5, and transmits the corresponding temperature signal and the corresponding humidity signal to controller 10. When the temperature detected by temperature and humidity detector I19 minus the temperature detected by temperature and humidity detector II22 is greater than 15°C, and / or the relative humidity detected by temperature and humidity detector I19 minus the relative humidity detected by temperature and humidity detector II22 is greater than 10%, alarm module 16 sends an alarm command to alarm 28, and alarm module 16 sends a flashing command to fault light 29, then further inspection by personnel is required.

[0106] The temperature difference and relative humidity between temperature and humidity detectors I19 and II22 are used to determine the sealing and operational status of duct I4, duct II5, and pulse dust collector 2. If the difference between the temperature detected by temperature and humidity detector I19 and the temperature detected by temperature and humidity detector II22 exceeds 15°C, the insulation layers of duct I4 and pulse dust collector 2 may be damaged, air leakage may occur between duct I4 and pulse dust collector 2, and the filter bags inside pulse dust collector 2 may become clogged due to condensation.

[0107] D. Dust detector II 21 detects the dust concentration inside pulse dust collector 2 and transmits the dust concentration signal to controller 10. When the dust concentration is higher than 300mg / L, alarm module 16 sends an alarm command to alarm 28 and alarm module 16 sends a flashing command to fault light 29, which requires further inspection by the staff.

[0108] The dust concentration detected by dust detector I18 and dust detector II21 determines whether the pulse dust collector 2 is operating normally. When the concentration is higher than 300mg / L, the filter bags in the pulse dust collector 2 may fall off or be damaged, and the machine needs to be stopped to check the filter bags.

[0109] E. Temperature and humidity detector Ⅲ24 detects the temperature and relative humidity inside the return air duct 6 and transmits the corresponding temperature signal and the corresponding humidity signal to the controller 10. When the temperature value is greater than 35℃ and / or the relative humidity is greater than 90%, the alarm module 16 sends an alarm command to the alarm 28 and sends a flashing command to the fault light 29, which requires further inspection by the staff.

[0110] The working efficiency and operating status of heat exchanger 3 are determined by temperature and humidity detectors II 22 and III 24. When the temperature measured by temperature and humidity detector III 24 is higher than 35℃, it indicates that the refrigeration system of heat exchanger 3 has failed, and it is necessary to focus on checking whether the pipe valves in the refrigeration system are open normally and whether the external circulation pump 26 is damaged.

[0111] F. Wind pressure sensor I 20 detects the wind pressure in duct II 5 and transmits the corresponding wind pressure signal to controller 10; wind pressure sensor II 23 detects the wind pressure in pulse dust collector 2 and transmits the corresponding wind pressure signal to controller 10. When the wind pressure difference between the two locations is greater than 3500Pa, alarm module 16 sends an alarm command to alarm 28 and alarm module 16 sends a flashing command to fault light 29, requiring further inspection by personnel.

[0112] The operation of pulse dust collector 2 is determined by wind pressure sensor I20 and wind pressure sensor II23. If the wind pressure difference is greater than 3500Pa, the pressure loss and resistance of pulse dust collector 2 are high, and it is necessary to check for condensation, bag clogging, etc.

[0113] G. The blowing pressure of the pulse dust collector 2 blow pipe is controlled to be no lower than the set value by the electromagnetic pulse valve 36 (Wuxi Yongda Automation Equipment Manufacturing Co., Ltd.);

[0114] The pulse-jet cleaning system can be implemented using three methods: timed, pressure-controlled, and manual cleaning. For example, the cleaning interval can be set to 15 seconds, the inlet and outlet pressure difference can be set to 2500 Pa, and pressure-controlled cleaning can be prioritized. The dust collector control system monitors operating parameters such as cleaning, inlet flue gas temperature and humidity, and cleaning pressure in real time. The control interface is integrated into the zero-emission system terminal, displaying the process and sensor values ​​on a human-machine interface (HMI) to achieve dual control from the work site and the central control room.

[0115] H. The wind pressure sensor Ⅲ25 detects the wind pressure in the return air duct 6 and transmits the wind pressure signal to the controller 10. When the wind pressure is higher or lower than the set value of -5 to -30 Pa, the wind pressure control module 15 sends a command to the variable frequency induced draft fan 27 to ensure that the wind pressure in the return air duct 6 near the cooler 1 section is within the set wind pressure range; or, the alarm module 16 sends an alarm command to the alarm 28, and the alarm module 16 sends a flashing command to the fault light 29, in which case the staff needs to carry out further inspection.

[0116] Among them, the wind pressure sensor Ⅲ25 is used to determine whether the entire return air duct 6 is normal, and the return air duct 6 at the front end of the variable frequency induced draft fan 27 achieves a slight negative pressure (-5 to -30Pa), which is achieved through the variable frequency control of the variable frequency induced draft fan 27.

Claims

1. A control system for zero emission of waste gas from feed production, installed in a feed production system, the control system comprising a cooler (1), a pulse dust collector (2), and a heat exchanger (3), wherein the inlet of the cooler (1) is connected to the feed production system, the outlet of the cooler (1) is connected to the inlet of the pulse dust collector (2) via duct I (4), the outlet of the pulse dust collector (2) is connected to the inlet of the heat exchanger (3) via duct II (5), and the outlet of the heat exchanger (3) is connected to the return air outlet of the cooler (1) via a return air pipe (6), and the cooler (1), the pulse dust collector (2), and the heat exchanger (3) form a circulation path for waste gas recovery and reuse; the duct I (4), the pulse dust collector (2), the duct II (5), and the heat exchanger (3) are all provided with a heat insulation layer, characterized in that, The chilled water outlet of the heat exchanger (3) is connected to the chilled water tank (8) through the chilled water return pipe I (7), and the chilled water tank (8) is connected to the chilled water inlet of the heat exchanger (3) through the chilled water supply pipe I (9). An external circulation path for chilled water recycling and reuse is formed between the heat exchanger (3), the chilled water return pipe I (7), the chilled water tank (8) and the chilled water supply pipe I (9). The control system further includes a controller (10), a data acquisition unit (11), and an execution unit (12). The controller (10) is connected to the human-machine interface (13) through a data input interface. The controller (10) is connected to the data acquisition unit (11) through a data feedback interface. The controller (10) is connected to the execution unit (12) through a data output interface. The controller (10) includes a temperature control module (14), a wind pressure control module (15), an alarm module (16), and a pulse control module (37). The data acquisition unit (11) includes a sensor group for the acquisition and transmission of feedback data in the zero-emission treatment process of feed production exhaust gas. The sensor group includes a temperature sensor I (17) installed in the cooler (1), a dust detector I (18) and a temperature and humidity detector I (19) installed on the air duct I (4), a wind pressure sensor I (20) installed on the pulse dust collector (2), a dust detector II (21) and a temperature and humidity detector II (22) and a wind pressure sensor II (23) installed on the air duct II (5), and a temperature and humidity detector III (24) and a wind pressure sensor III (25) installed on the return air duct (6). The temperature sensor I (17), dust detector I (18), temperature and humidity detector I (19), wind pressure sensor I (20), dust detector II (21), temperature and humidity detector II (22), wind pressure sensor II (23), temperature and humidity detector III (24), and wind pressure sensor III (25) are all connected to the controller (10) via electrical signals. The execution unit (12) includes a group of devices for executing the instructions of the controller (10) in the zero-emission treatment process of feed production exhaust gas. The group of devices includes an external circulation pump (26) installed on the chilled water supply pipe, a variable frequency induced draft fan (27) installed on the return air duct (6), an alarm (28) and a fault light (29), and an electromagnetic pulse valve (36) installed on the blow pipe of the pulse dust collector (2). The temperature control module (14) is connected to the external circulation pump (26) via an electrical signal, the wind pressure control module (15) is connected to the variable frequency induced draft fan (27) via an electrical signal, the alarm module (16) is connected to the alarm (28) and the fault light (29) via an electrical signal, and the pulse control module (37) is connected to the electromagnetic pulse valve (36) via an electrical signal. The control method involved in the control system includes the following steps: A. The return air obtained from the zero-emission treatment system for feed production exhaust gas is introduced into the cooler (1). Temperature sensor I (17) detects the temperature inside the cooler (1) and transmits the temperature signal to the controller (10). When the temperature is higher or lower than 20-35℃, the temperature control module (14) sends an instruction to the external circulation pump (26) to open or close, controlling the temperature in the cooler (1) within the set temperature range; or, the alarm module (16) sends an alarm instruction to the alarm (28), and the alarm module (16) sends a flashing instruction to the fault light (29), then the staff needs to conduct further inspection; B. Dust detector I (18) detects the dust concentration in duct I (4) and transmits the dust concentration signal to the controller (10). When the dust concentration is higher than 300 mg / L, the alarm module (16) sends an alarm command to the alarm (28) and the alarm module (16) sends a flashing command to the fault light (29). Then, the staff needs to carry out further inspection. C. Temperature and humidity detector I (19) detects the temperature and relative humidity inside air duct I (4), and temperature and humidity detector II (22) detects the temperature and relative humidity inside air duct II (5). The corresponding temperature signal and the corresponding humidity signal are transmitted to the controller (10). When the temperature detected by temperature and humidity detector I (19) minus the temperature detected by temperature and humidity detector II (22) is greater than 15°C, and / or the difference between the relative humidity detected by temperature and humidity detector I (19) and the relative humidity detected by temperature and humidity detector II (22) is greater than 10%, the alarm module (16) sends an alarm command to the alarm (28), and the alarm module (16) sends a flashing command to the fault light (29). Then, the staff needs to conduct further inspection. D. Dust detector II (21) detects the dust concentration in the pulse dust collector (2) and transmits the dust concentration signal to the controller (10). When the dust concentration is higher than 300mg / L, the alarm module (16) sends an alarm command to the alarm (28) and the alarm module (16) sends a flashing command to the fault light (29). Then, the staff needs to carry out further inspection. E. Temperature and humidity detector Ⅲ (24) detects the temperature and relative humidity inside the return air duct (6) and transmits the corresponding temperature signal and the corresponding humidity signal to the controller (10). When the temperature value is greater than 35°C and / or the relative humidity is greater than 90%, the alarm module (16) sends an alarm command to the alarm (28), and the alarm module (16) sends a flashing command to the fault light (29), then the staff needs to carry out further inspection. F. The wind pressure sensor I (20) detects the wind pressure in the air duct II (5) and transmits the corresponding wind pressure signal to the controller (10); the wind pressure sensor II (23) detects the wind pressure in the pulse dust collector (2) and transmits the corresponding wind pressure signal to the controller (10). When the wind pressure difference between the two places is greater than 3500Pa, the alarm module (16) sends an alarm command to the alarm (28), and the alarm module (16) sends a flashing command to the fault light (29). Then, the staff needs to carry out further inspection. G. The blowing pressure of the pulse dust collector (2) blow pipe is controlled to be no less than 0.4 MPa by means of electromagnetic pulse valve (36); H. The wind pressure sensor III (25) detects the wind pressure in the return air duct (6) and transmits the wind pressure signal to the controller (10). When the wind pressure is higher or lower than the set value, the wind pressure control module (15) sends a command to the variable frequency induced draft fan (27) to ensure that the wind pressure in the section of the return air duct (6) near the cooler (1) is within the range of -5 to -30 Pa; or, the alarm module (16) sends an alarm command to the alarm (28), and the alarm module (16) sends a flashing command to the fault light (29), then the staff needs to carry out further inspection.

2. The control system for zero emission of waste gas from feed production according to claim 1, characterized in that, The controller (10) and the human-machine interface (13) are both located on the PLC control cabinet in the central control room, and the alarm (28) and the fault light (29) are both located on the control cabinet.

3. The control system for zero emission of waste gas from feed production according to claim 1, characterized in that, There are four temperature sensors I (17), which are evenly distributed in the cooler (1).

4. The control system for zero emission of waste gas from feed production according to claim 1, characterized in that, The dust detector I (18) and the temperature and humidity detector I (19) are installed in the air duct I (4) section near the air outlet of the cooler (1), the temperature and humidity detector III (24) is installed in the return air duct (6) section near the heat exchanger (3), and the wind pressure sensor III (25) is installed in the return air duct (6) section near the variable frequency induced draft fan (27).

5. The control system for zero emission of waste gas from feed production according to claim 1, characterized in that, The heat exchanger (3) is connected to a condensate collection tank (31) via a condenser pipe (30).

6. The control system for zero emission of waste gas from feed production according to claim 1, characterized in that, The outlet of the chilled water tank (8) is connected to the return water port of the refrigeration unit (33) in the feed production line through the chilled water return pipe II (32). The outlet of the refrigeration unit (33) in the feed production line is connected to the inlet of the chilled water tank (8) through the chilled water supply pipe II (34). The chilled water tank (8), chilled water return pipe II (32), refrigeration unit (33) and chilled water supply pipe II (34) form an internal circulation path for chilled water recycling and reuse. An internal circulation pump (35) is provided on the chilled water return pipe II (32). The temperature control module (14) is also connected to the internal circulation pump (35) through an electrical signal.

7. The control system for zero emission of waste gas from feed production according to claim 6, characterized in that, The chilled water tank (8) is provided with an overflow port (81) and a water inlet (82) at the top, and a drain port (83) at the bottom.

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