Intelligent dust removal and waste gas integrated treatment system and control method for commercial mixing and stirring station

Abstract

This invention relates to the field of environmental protection equipment technology, and discloses an intelligent integrated dust removal and waste gas treatment system and control method for commercial concrete mixing plants. The system includes a source collection system, a gas delivery system, a dust removal system, a waste gas purification system, a recovery and emission system, a monitoring and control system, and a safety protection system. Multiple pollution sources converge into the main pipeline via collection branches equipped with electric regulating valves and negative pressure sensors. The dust removal system includes a cyclone pre-separator and a bag filter unit. The waste gas purification system includes a wet scrubbing unit, a demisting and dehydration unit, a dual-bed adsorption unit, and a catalytic oxidation unit. Bypass valves and switching valves form a dry high-efficiency dust removal path, a wet synergistic purification path, an adsorption purification path, and a regeneration catalytic treatment path. This invention can adapt to the multi-pollution source, multi-time period, and load fluctuation conditions of commercial concrete mixing plants, and reduces the risk of downstream adsorbents and catalysts being impacted by dust and abnormal operating conditions.

Description

Technical Field

[0001] This invention relates to the field of environmental protection equipment technology, and in particular to an intelligent integrated dust removal and waste gas treatment system and control method for commercial concrete mixing plants. Background Technology

[0002] Commercial concrete mixing plants typically include multiple production and auxiliary workstations such as powder silos, powder metering hoppers, aggregate feeding systems, mixing hosts, admixture storage and conveying systems, enclosed main building spaces, vehicle washing areas, and plant roads. During the powder conveying, metering, feeding, and mixing processes, high-concentration or instantaneously fluctuating dust-laden airflows are generated. In scenarios where liquid admixture storage tanks, enclosed auxiliary heating facilities, or specific chemical admixtures are installed, low-concentration total volatile organic compounds (TVOCs) or odorous gases may also be generated. Different pollution sources exhibit significant differences in generation time, gas volume, particulate matter load, humidity, and organic matter concentration.

[0003] The pollution control devices of existing commercial concrete mixing plants are usually configured according to a single pollution source or a single pollutant type. For example, independent dust collectors are set up at the powder silos, metering hoppers or mixing hosts, or fixed spray, bag filter or adsorption devices are used. When multiple independent units run in parallel, problems such as redundant installation of fans and pipelines, branch air competition, insufficient or excessive local negative pressure, uneven load on filter media, and high energy consumption during no-load operation are likely to occur.

[0004] When particulate matter, soluble gases, odors, and low-concentration organic waste gas are present at the same site, simply fixing and connecting all treatment units such as cyclone separation, bag filter, wet scrubbing, adsorption, and catalytic oxidation in series will not only increase system resistance and energy consumption, but may also subject the subsequent adsorbent and catalyst to the impact of dust, humidity, or abnormal combustible gas concentrations. Especially between normal adsorption conditions and adsorption bed desorption and regeneration conditions, if the purified gas path and concentrated desorbed gas path are not clearly distinguished, it is easy to cause the catalytic oxidation unit to operate ineffectively for a long time or to have unclear safety control boundaries.

[0005] In addition, existing systems often control fans, dust removal, spraying, adsorption beds and catalytic devices separately. There is a lack of unified scheduling between units based on parameters such as pollutant type, real-time concentration, negative pressure, differential pressure, temperature and humidity and the proportion of lower explosive limits. When the pollution source is intermittently turned on, the load changes suddenly or the equipment is abnormal, it is difficult to achieve coordinated control of treatment path, air volume distribution, adsorption bed switching and safety interlock.

[0006] Therefore, there is a need for an intelligent integrated dust removal and exhaust gas treatment system and control method for commercial concrete mixing plants, which enables multiple collection branches to implement zoned negative pressure control according to the work station status, and to switch between different purification paths according to the type and load of pollutants. At the same time, clear entry permit conditions and abnormal interlocking measures are set for the adsorption regeneration and catalytic oxidation processes to improve the system's operational stability and adaptability. Summary of the Invention

[0007] In response to the characteristics of commercial concrete mixing plants, such as numerous pollution sources, asynchronous operation times, and significant fluctuations in pollution load, zoned negative pressure coordination among multiple collection branches is achieved to reduce branch air leakage, local dust emission, and ineffective ventilation. Avoid connecting all purification units in series under all operating conditions; instead, use bypass valves and switching valves to create a treatment path that matches the type of pollutant. Clarify the gas path relationship between normal adsorption purification and adsorption bed desorption regeneration, so that the purified gas after normal adsorption enters the emission system, while the concentrated desorption waste gas enters the catalytic oxidation unit when safety conditions are met. By using detection signals such as particulate matter, TVOC, temperature and humidity, differential pressure, negative pressure, oxygen content, and the percentage of the lower explosive limit, the system can uniformly control the dust removal, adsorption bed switching, desorption and regeneration, catalytic oxidation start-up and shutdown, and abnormal interlocking.

[0008] To solve the above-mentioned technical problems, the present invention provides an intelligent integrated dust removal and exhaust gas treatment system for commercial concrete mixing plants, including a source collection system, an air conveying system, a dust removal system, an exhaust gas purification system, a recycling and emission system, a monitoring and control system, and a safety protection system.

[0009] The source collection system includes multiple collection branches corresponding to multiple pollutant generating stations. Each collection branch is equipped with a branch electric regulating valve and a negative pressure sensor, and the gas is connected to the main pipeline through branch ducts. The gas delivery system includes the main pipeline and a variable frequency main fan. The monitoring and control system coordinates and adjusts the opening degree of the branch electric regulating valve and the frequency of the variable frequency main fan according to the production status of each station, the real-time negative pressure of the corresponding branch, and the particulate matter concentration.

[0010] The dust removal system includes a pre-separation unit and a bag filter unit in sequence along the airflow direction. The pre-separation unit is preferably a cyclone pre-separator, and the bag filter unit is preferably a pulse jet bag filter. The pre-separation unit performs peak reduction and separation of coarse particles in the high-concentration dust-laden airflow, and then the bag filter unit performs fine filtration.

[0011] The exhaust gas purification system includes a wet scrubbing unit, a demisting and dehydration unit, an adsorption unit, and a catalytic oxidation unit. Bypass valves and switching valves are installed between the dust removal system, each exhaust gas purification unit, and the recovery and emission system to form a dry high-efficiency dust removal path, a wet synergistic purification path, an adsorption purification path, and a regeneration catalytic treatment path. Figure 1 This is used to indicate the overall relationship between functional units, and does not mean that all units are always connected in series and work simultaneously under any operating condition.

[0012] The dry high-efficiency dust removal path is used for operating conditions where particulate matter is the main pollutant. The gas passes through a cyclone pre-separator and a bag filter unit in sequence before entering the recovery and emission system. The wet co-purification path is used for operating conditions that require further treatment of residual fine dust, soluble gases, or odor components. After completing dry dust removal, the gas enters a wet scrubbing unit and a demisting and dehydration unit before entering the recovery and emission system. The adsorption purification path is used for operating conditions that require deep purification of low-concentration TVOCs. The gas enters the adsorption unit after dust removal, wet scrubbing, and demisting and dehydration. The purified gas after normal adsorption enters the recovery and emission system.

[0013] The adsorption unit preferably adopts a dual-bed structure. When one of the adsorption beds reaches the set breakthrough state, the monitoring and control system switches it to offline state and puts the backup adsorption bed into normal adsorption. The offline adsorption bed is desorbed by introducing hot air or inert gas through the heating regeneration unit. The resulting concentrated desorbed waste gas enters the regeneration catalytic treatment path and enters the catalytic oxidation unit only when the particulate matter concentration, combustible gas concentration, oxygen content and temperature at the catalytic oxidation inlet meet the preset safety conditions.

[0014] The monitoring and control system preferably adopts a PLC, industrial touch screen and Internet of Things platform architecture to collect at least some of the signals from particulate matter concentration, TVOC concentration, temperature, humidity, oxygen content, lower explosive limit ratio, differential pressure, negative pressure, liquid level, pH, current, vibration and valve position signals, and perform pollution condition identification, path selection, air volume adjustment, dust removal control, adsorption bed switching, desorption regeneration, catalytic oxidation start and stop, emission judgment and fault interlock.

[0015] The present invention also provides a control method, including steps such as signal acquisition, pollution condition identification, treatment path selection, zoned negative pressure and coordinated adjustment of purification units, adsorption bed switching and desorption regeneration, emission determination and abnormal interlocking.

[0016] Preferably, the bag filter unit is equipped with a differential pressure sensor, an outlet particulate matter monitor, an ash hopper level gauge, and an ash unloading mechanism. The monitoring and control system executes a cleaning strategy that combines timing and status based on the differential pressure value, differential pressure growth rate, and outlet particulate matter concentration.

[0017] The wet washing unit adopts a spray washing tower structure. The main body of the washing tower is equipped with a pH sensor, a liquid level sensor and a drain valve, and is connected to a circulating water tank to realize the recycling of washing liquid.

[0018] Each adsorption bed in the adsorption unit is equipped with an inlet valve, an outlet valve, a temperature sensor, and inlet and outlet TVOC monitoring points. The ratio of outlet TVOC concentration to inlet TVOC concentration is used as one of the parameters for judging the breakthrough state, and is corrected in combination with cumulative running time, temperature, and humidity.

[0019] The catalytic oxidation unit includes a heating chamber, a catalytic reaction chamber, a heat exchange chamber, a catalyst support, a temperature sensor, an oxygen content sensor, and a lower explosion limit ratio sensor.

[0020] The safety protection system includes one or more of the following: flame arresters, fire dampers, explosion relief devices, and static grounding devices, and is linked to the monitoring and control system.

[0021] The monitoring and control system is connected to the branch electric regulating valves, negative pressure sensors, variable frequency main fans, bypass valves, switching valves, and detection elements installed in each purification unit. It is used to perform pollution condition identification, treatment path selection, branch air volume adjustment, dust removal control, adsorption bed switching, desorption and regeneration control, catalytic oxidation start and stop, and fault interlock based on at least some of the detection signals of particulate matter concentration, total volatile organic compound concentration, temperature, humidity, differential pressure, negative pressure, oxygen content, and lower explosive limit ratio.

[0022] The spray assembly includes a liquid supply rack, a control mechanism, and a switching mechanism. The control rack is driven to move by an electric push rod, causing the linkage protrusion to move along the spiral linkage groove on the linkage rod. Then, the switching disc is driven to rotate by a gear set, so that the connecting channels corresponding to different specifications of spray heads can selectively connect with the liquid supply channel. Beneficial effects

[0023] By using electric regulating valves, negative pressure sensors, and variable frequency main air mechanism components with negative pressure coordination structure in multiple collection branches, suction can be distributed according to the actual operating status of each workstation, reducing the probability of branch air grabbing, insufficient local negative pressure, or excessive air extraction.

[0024] By using bypass valves and switching valves to create multiple treatment paths, particulate matter-dominant conditions do not need to be forced to pass through all wet scrubbing, adsorption, and catalytic units, thereby reducing unnecessary system resistance and ineffective operation.

[0025] By adopting a pre-protection method of cyclone pre-separation and bag filter fine dust removal, the risk of downstream wet scrubbing, adsorption and catalysis units being impacted by high dust loads can be reduced.

[0026] By clearly distinguishing the normal adsorption purification path from the adsorption bed desorption regeneration and catalytic oxidation path, the purified gas after normal adsorption directly enters the recovery and emission system, while the concentrated desorption waste gas enters the catalytic oxidation unit when safety conditions are met. This helps to improve the clarity of the treatment logic and the safety of operation.

[0027] The adsorption bed status is determined by the TVOC concentration ratio at the inlet and outlet of the adsorption bed, the cumulative running time, and the temperature and humidity correction conditions, which enables online switching and offline regeneration of the two beds.

[0028] The catalytic oxidation unit is equipped with start-up permission and interlock logic related to particulate matter, oxygen content, lower explosive limit ratio, and temperature. In abnormal situations, it can execute actions such as stopping heating, replenishing air dilution, bypass switching, or interlock shutdown.

[0029] Dust, circulating washing liquid, and waste heat from catalytic reaction can be recovered or recycled separately. The Internet of Things platform can record emissions, energy consumption, alarms, and maintenance data, providing a data foundation for operation and maintenance. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below.

[0031] The accompanying drawings described below are only related to some embodiments of the invention and are not intended to limit the invention.

[0032] In the attached diagram: Figure 1 A system structure diagram of the present invention is shown.

[0033] Figure 2 A schematic diagram of the overall structure of the spray scrubbing tower of the present invention is shown.

[0034] Figure 3 A schematic diagram of the spray assembly of the present invention is shown.

[0035] Figure 4 The present invention is shown. Figure 3 A schematic diagram of the bottom structure.

[0036] Figure 5 A schematic diagram of the internal structure of the spray assembly of the present invention is shown.

[0037] Figure 6 The present invention is shown. Figure 5 Enlarged structural diagram of part A in the middle.

[0038] Figure 7 A schematic diagram of the disassembled spray assembly of the present invention is shown.

[0039] Figure 8 A schematic diagram of the internal structure of the present invention when switching the use of the spray nozzle is shown.

[0040] Figure 9 The present invention is shown. Figure 8 Enlarged detailed structural diagram of part B in the middle.

[0041] List of reference numerals 1. Source collection system; 2. Pre-separation unit; 3. Bag filter unit; 4. Wet scrubbing unit; 5. Adsorption unit; 6. Catalytic oxidation unit; 7. Recovery and emission system; 8. Monitoring and control system; 901. Scrubber body; 921. Liquid supply rack; 9211. Liquid supply channel; 93. Control mechanism; 931. Electric push rod; 932. Control frame; 9321. Linkage protrusion; 94. Switching mechanism; 941. Switching plate; 9411. Connecting channel; 942. Linkage rod; 9421. Linkage trough; 943. Spray nozzle. Detailed Implementation

[0042] Example 1: System structure and operation mode of intelligent dust removal and exhaust gas treatment integrated device for commercial concrete mixing plants: as follows Figure 1 As shown, the integrated device in this embodiment includes a source collection system 1, a gas delivery system, a dust removal system, a waste gas purification system, a recycling and emission system 7, a monitoring and control system 8, and a safety protection system. Figure 1 This diagram illustrates the overall relationship between the functional units. In actual operation, the bypass valve and the switching valve select the appropriate processing path according to different operating conditions. It is not required that all processing units be connected in series under any operating condition.

[0043] The source collection system 1 sets up collection points at various locations, including the breather inlet of the powder silo, the powder metering hopper, the aggregate feeding point, the mixing host, the enclosed space of the main building, the suction inlet of the admixture storage tank, the vehicle washing platform, and the ground dust collection hood. Each collection point is connected to the main pipeline through a branch duct and is equipped with a branch electric regulating valve and a negative pressure sensor. Depending on the site conditions, two or more collection points can be selected to form a collection network.

[0044] The air delivery system includes the main pipeline and the variable frequency main fan. The monitoring and control system reads the real-time negative pressure of each working branch and the operating status of the corresponding workstation. When the workstation starts, it opens or increases the opening of the electric regulating valve of the corresponding branch. After the workstation stops, it delays or closes the valve according to the need for residual dust extraction. At the same time, it adjusts the frequency of the variable frequency main fan according to the negative pressure status of multiple working branches to keep the suction of each branch matching the current production conditions.

[0045] When multiple branches are working simultaneously, the monitoring and control system 8 prioritizes adjusting the electric regulating valves of each branch according to the negative pressure deviation of each branch, and then adjusts the frequency of the variable frequency main fan according to the overall negative pressure status of multiple working branches and the pressure difference of the treatment device. Thus, after one branch is taken out of operation, the other branches can avoid excessive suction due to the failure to adjust the total air volume in time. When multiple branches are put into operation at the same time, the local dust emission caused by branches competing for air can be reduced.

[0046] The dust removal system includes a pre-separation unit 2 and a bag filter unit 3. The pre-separation unit 2 is preferably a cyclone pre-separator. The collected dust-laden airflow forms a rotating flow along the cylinder wall of the cyclone pre-separator. Larger particles move towards the wall under centrifugal force and fall into the ash hopper to reduce the instantaneous dust load of the subsequent bag filter unit 3.

[0047] The bag filter unit 3 is preferably a pulse jet bag filter, and is equipped with a differential pressure sensor, an outlet particulate matter monitor, an ash hopper level gauge, and an ash discharge mechanism. The monitoring and control system 8 continuously reads the differential pressure value, differential pressure growth trend, and outlet particulate matter concentration of the bag filter unit 3. When the cleaning conditions are met, pulse cleaning is implemented. When the differential pressure continues to be higher than the fault threshold or the outlet particulate matter concentration rises abnormally, a maintenance alarm is output, and load reduction operation can be performed.

[0048] The exhaust gas purification system includes a wet scrubbing unit 4, a demisting and dehydration unit, an adsorption unit 5, and a catalytic oxidation unit 6. Bypass valves and switching valves are set between each unit to select the dry high-efficiency dust removal path, the wet synergistic purification path, or the adsorption purification path according to the pollution conditions. When the adsorption bed enters offline regeneration, the regeneration catalytic treatment path is activated.

[0049] Multi-source collection and zoned negative pressure control: When the commercial concrete mixing plant is running, different work stations do not generate dust continuously and simultaneously. For example, powder silo feeding, powder metering, aggregate feeding and mixing host feeding can occur at different time periods. The monitoring and control system 8 determines the collection branch to be put into operation based on the production equipment operation signal and uses negative pressure sensors to detect the actual negative pressure of each branch.

[0050] When a workstation enters a dust-generating state, the monitoring and control system 8 opens the corresponding branch electric regulating valve and adjusts the valve opening according to the real-time negative pressure. When multiple workstations are running simultaneously, the monitoring and control system 8 coordinates multiple branch valves and variable frequency main fans to maintain the required negative pressure in multiple working branches. The enclosed space of the main building can maintain a slight negative pressure to reduce fugitive emissions. For powder metering-related branches, excessive ventilation can be limited to avoid adverse effects on the metering process.

[0051] Processing path selection, dry high-efficiency dust removal path: suitable for working conditions such as powder silo feeding, powder metering, aggregate feeding or mixing operations where particulate matter is the main pollutant. The gas enters the recovery and emission system 7 after passing through the pre-separation unit 2 and the bag filter unit 3 in sequence.

[0052] Wet co-processing purification path: suitable for situations where residual fine dust, soluble gases or odor components still need to be treated after dust removal. The gas passes through the pre-separation unit 2, bag filter unit 3, wet washing unit 4 and demisting and dehydration unit in sequence before entering the recovery and emission system 7.

[0053] Adsorption purification path: Suitable for working conditions with low concentration TVOC deep purification requirements. After the gas completes the aforementioned dust removal, wet washing and demisting and dehydration, it enters the adsorption unit 5. The purified gas after normal adsorption enters the recovery and emission system 7. It is not required to continuously pass through the catalytic oxidation unit 6 during the normal adsorption stage.

[0054] Regeneration catalytic treatment path: When a certain adsorption bed in adsorption unit 5 reaches the set breakthrough state and switches to an offline bed, hot air or inert gas is introduced through the heating regeneration unit for desorption. The concentrated desorbed waste gas formed enters the catalytic oxidation unit 6 for treatment when the inlet conditions of the catalytic oxidation unit 6 meet the preset safety conditions.

[0055] Wet washing and circulating water control: The wet washing unit 4 is preferably a spray washing tower. The gas enters from the bottom of the tower and comes into countercurrent contact with the circulating washing liquid from top to bottom. The residual fine dust is captured by the liquid droplets, and the soluble gas or some odor components are absorbed by the washing liquid. The washed gas passes through the demisting and dehydration unit to remove the entrained liquid droplets, and then enters the subsequent unit or the recovery and emission system 7.

[0056] The main body 901 of the washing tower is equipped with a pH sensor, a liquid level sensor and a drain valve, and is connected to the circulating water tank. The monitoring and control system 8 adjusts the dosing, replenishment and draining status according to the pH, liquid level and conductivity signal when the conductivity sensor is set, so as to keep the circulating washing liquid within the usable range.

[0057] Dual-bed adsorption, breakthrough judgment, and offline regeneration: Adsorption unit 5 adopts a dual-bed structure consisting of at least two adsorption beds. The adsorbent can be one or more of granular activated carbon, activated carbon fiber felt, or honeycomb activated carbon. Each adsorption bed is equipped with an inlet valve, an outlet valve, a temperature sensor, and inlet and outlet TVOC monitoring points.

[0058] During the normal adsorption phase, at least one adsorption bed is online. The monitoring and control system 8 continuously acquires the TVOC concentration C_in at the inlet and the TVOC concentration C_out at the outlet of the online adsorption bed, and calculates or determines the ratio of the outlet concentration to the inlet concentration. When C_out / C_in reaches the set breakthrough ratio, or when the cumulative running time of the adsorption bed reaches the set threshold, the monitoring and control system 8 performs bed switching; when necessary, the switching conditions can also be corrected based on temperature and humidity signals.

[0059] After the bed switching, the standby adsorption bed is put into online adsorption, and the adsorption bed that has reached the set breakthrough state enters offline regeneration. The heating regeneration unit introduces hot air or inert gas into the offline bed to desorb the adsorbed TVOC from the adsorbent and form concentrated desorbed waste gas. This concentrated desorbed waste gas is transported to the catalytic oxidation unit 6 through an independent regeneration catalytic treatment path.

[0060] The catalytic oxidation unit 6 includes a heating chamber, a catalytic reaction chamber, a heat exchange chamber, and a catalyst support. It is equipped with a temperature sensor, an oxygen content sensor, and a lower explosion limit ratio sensor. The catalyst can be a noble metal type or a transition metal oxide type honeycomb catalyst, and the operating temperature can be 250-420℃.

[0061] Before the concentrated desorbed waste gas enters the catalytic oxidation unit 6, the monitoring and control system 8 reads the particulate matter concentration, oxygen content and lower explosive limit ratio at the catalytic oxidation inlet. As a preferred embodiment, when the inlet particulate matter concentration is less than 10 mg / m³, the combustible gas concentration is less than 25% of the lower explosive limit and the oxygen content meets the preset requirements, the concentrated desorbed waste gas is allowed to enter the catalytic oxidation unit 6.

[0062] When the lower explosion limit reaches the warning value, the monitoring and control system 8 prioritizes to perform make-up air dilution and stop heating; if it still cannot be restored to the safe range, or if the temperature exceeds the limit or the oxygen content is abnormal, the catalytic path is closed and the safety bypass is opened, so that the abnormal gas returns to the front end for processing or enters the safety processing branch. At the same time, according to the fault level, alarm, load reduction or interlock shutdown is performed.

[0063] The high-temperature purified gas after catalytic oxidation can exchange heat with the inlet gas in the heat exchange chamber to recover heat, and the treated gas enters the recovery and emission system 7.

[0064] The system includes a dust collection spiral, a dust collection silo, a circulating water tank, and an exhaust stack. The dust collected in the ash hopper of the bag filter unit 3 is transported to the dust collection silo via an ash unloading mechanism and a dust collection spiral. When production quality and formula requirements are met, resources can be utilized according to the actual management system.

[0065] The washing liquid in the wet scrubbing unit 4 is recycled after sedimentation and pH adjustment in the circulating water tank. The exhaust stack can be equipped with emission monitoring equipment such as particulate matter monitor, TVOC monitor, temperature sensor and flow meter.

[0066] The monitoring and control system 8 can record operation logs, alarm events, emission data, energy consumption data and maintenance records through the Internet of Things platform, and generate environmental compliance reports and equipment health assessment results. The above information processing functions are used to assist operation and maintenance, and do not replace on-site detection and interlocking control of actual emission status and equipment safety status.

[0067] Example 2: Automatic switching structure for multi-specification spray nozzles, such as... Figures 2 to 9 As shown, the wet washing unit 4 is a spray washing tower structure, including a washing tower body 901 and a spray assembly. The spray assembly consists of a liquid supply rack 921, a control mechanism 93 and a switching mechanism 94.

[0068] The liquid supply rack 921 is fixedly installed inside the washing tower body 901. The control mechanism 93 includes an electric push rod 931 and a control frame 932. The electric push rod 931 is fixedly installed on the top of the washing tower body 901, and the control frame 932 is fixedly installed on the bottom of the push rod of the electric push rod 931.

[0069] The switching mechanism 94 includes a switching disk 941, a linkage rod 942, and spray nozzles 943. The switching disk 941 is rotatably connected to the bottom of the liquid supply rack 921, the linkage rod 942 is rotatably connected to the top of the liquid supply rack 921, and multiple spray nozzles 943 are installed at the bottom of the switching disk 941.

[0070] The liquid supply rack 921 has a liquid supply channel 9211 inside, one end of which is connected to an external liquid supply device. The switching disk 941 has multiple connecting channels 9411 arranged circumferentially inside, and each connecting channel 9411 has a spray nozzle 943 installed at the bottom. The spray nozzles 943 corresponding to different connecting channels 9411 have different specifications. In one working position, only one connecting channel 9411 is connected to the liquid supply channel 9211. The external liquid supply device (circulating pump) supplies the spray liquid into the interior of the connecting channel 9411. The spray liquid can enter the interior of the connecting channel 9411 connected to it through the liquid supply channel 9211, so that the spray liquid can finally be sprayed out from the spray nozzle 943 at the bottom of the connecting channel 9411 for spraying operation, which is stable in use.

[0071] The linkage rod 942 has a spiral linkage groove 9421 on its outer periphery, and the control frame 932 has a linkage protrusion 9321. The linkage protrusion 9321 is inserted into the linkage groove 9421, and the linkage rod 942 and the rotating shaft of the switching disk 941 are connected by a gear set.

[0072] When the electric push rod 931 extends or retracts, the control frame 932 moves vertically, the linkage protrusion 9321 moves along the linkage groove 9421 and drives the linkage rod 942 to rotate; the linkage rod 942 drives the switching disk 941 to rotate through the gear set, so that different connecting channels 9411 rotate sequentially to the working position connected to the liquid supply channel 9211, thereby enabling the switching of different specifications of spray nozzles 943 without disassembling the nozzles.

[0073] In one specific embodiment, each switching mechanism 94 is equipped with six different specifications of spray nozzles 943. The nozzle specifications can be configured according to the spray flow rate, spray angle, droplet size or pollution load requirements. During switching, the monitoring and control system 8 can control the electric push rod 931 to move to the corresponding position according to the current operating mode or operator instructions.

[0074] During operation, when it is necessary to switch the spray nozzle 943 to adapt to the corresponding spraying conditions, the switching operation can be achieved through the switching mechanism 94. There is no need for manual installation or removal of the spray nozzle 943. When the electric push rod 931 extends or retracts, it can move the control frame 932 up and down. When the control frame 932 moves up and down, the linkage protrusion 9321 can drive the linkage rod 942 to rotate through the linkage groove 9421. When the linkage rod 942 rotates, it can drive the switching disk 941 to rotate through the gear set. When the switching disk 941 rotates, it can change the connecting channel 9411 connected to the liquid supply channel 9211. Thus, only the connecting channel 9411 connected to the liquid supply channel 9211 and the spray nozzle 943 at its bottom will perform spraying operations. The required spray nozzle 943 can be switched to the working position (the position when connected to the liquid supply channel 9211) by simply switching it. The switching is quick and convenient.

[0075] Example 3: This example provides an intelligent dust removal and exhaust gas treatment control method for commercial concrete mixing plants, which can be executed by the monitoring and control system 8. The method includes the following steps: S1. Signal Acquisition: Acquire at least some of the following signals from each collection branch and purification unit: particulate matter concentration, TVOC concentration, temperature, humidity, oxygen content, lower explosive limit ratio, differential pressure, negative pressure, liquid level, pH, current, vibration, and valve position signals. Simultaneously acquire the operating status of production equipment such as powder feeding, metering, aggregate feeding, and mixing host.

[0076] S2. Pollution Condition Identification: Identify the current pollutant type and pollution load level based on particulate matter concentration, TVOC concentration, temperature, humidity, and production conditions. The pollution load level can be divided into at least light load, medium load, and heavy load, with specific thresholds set based on equipment scale, processing capacity, and on-site commissioning results.

[0077] S3. Treatment path selection: When the pollutants are mainly particulate matter and the TVOC concentration is lower than the corresponding set threshold, select the dry high-efficiency dust removal path; when there is a need to treat high humidity, odor, or soluble gases, select the wet synergistic purification path; when the gas after dust removal and demisting has a need for deep TVOC purification, select the adsorption purification path.

[0078] S4. Coordinated Adjustment: Under the selected path, the monitoring and control system 8 adjusts the corresponding branch electric regulating valve according to the operating status of each work station and the negative pressure of the branch, and adjusts the frequency of the variable frequency main fan according to the negative pressure status of multiple working branches; at the same time, it controls the dust removal according to the differential pressure value, differential pressure growth rate and outlet particulate matter concentration of the bag filter unit 3, and controls the circulating water, replenishment and sewage discharge status according to the pH and liquid level of the wet scrubbing unit 4.

[0079] S5. Adsorption Bed Switching and Regeneration Catalytic Treatment: When the C_out / C_in ratio of the online adsorption bed reaches the set breakthrough ratio, or the cumulative operating time reaches the set threshold, the system switches to the standby adsorption bed and performs hot air or inert gas desorption on the offline adsorption bed. The resulting concentrated desorbed waste gas enters the catalytic oxidation unit 6 only when the particulate matter concentration, lower explosive limit ratio, oxygen content, and temperature at the catalytic oxidation inlet meet the preset safety conditions.

[0080] S6. Emission Judgment and Abnormal Interlock: Emission and status judgment are performed on the exhaust stack and key unit outlet; if the standard is met, the current operating status is maintained; if the set emission control value is exceeded, the treatment mode is upgraded or the operating status of the corresponding unit is adjusted; when the lower explosion limit ratio is exceeded, the temperature is exceeded, the oxygen content is abnormal, the differential pressure of the bag filter unit 3 is faulty, the fan is abnormal or other safety events are detected, one or more of the following measures are implemented: audible and visual alarm, load reduction, heating stoppage, make-up air dilution, bypass switching or interlock shutdown.

[0081] Example chart of running status: M1 Dry Dust Collector Particulate matter was the main component, and TVOC levels were below the set threshold. Pre-separation → Bag filter → Emission Adjust branch valves and main fan; perform differential pressure dust removal. Alarm and load reduction when differential pressure or outlet particulate matter is abnormal. M2 wet synergy High humidity, odor, or soluble gas treatment needs Pre-separation → Bag filter → Wet washing → Demisting and dehydration → Emission Control of spraying, pH, liquid level, replenishment and drainage Switch or shut down when liquid level, pH or equipment malfunctions. M3 Adsorption Purification The TVOC deep purification requirement is met and the pretreatment conditions are satisfied. Pre-separation → Bag filter → Wet washing → Demisting and dehydration → Adsorption → Emission Monitor C_in, C_out, temperature, and humidity to determine breakthroughs. When the adsorption bed reaches the breakthrough condition, the bed is cut. M4 Regenerated Catalyst The offline adsorption bed needs regeneration, and the catalytic inlet conditions are met. Offline adsorption bed desorption → waste gas concentration → catalytic oxidation → emission Control regeneration heating, dilution air, and catalytic start / stop Stop heating and shut down the catalytic pathway if LEL, temperature, or oxygen content is abnormal. E Emergency Status Any critical safety parameter exceeding the limit or equipment malfunction Switch to a safe branch or shut down depending on the fault level. Alarm, load reduction, make-up air dilution, bypass or interlock shutdown Abnormal gas is either returned to the front-end processing or enters the safety processing branch. The above state division is only used to illustrate the collaborative control logic. In actual implementation, more detailed states can be set according to the composition of pollution sources at the site, emission control requirements and equipment capacity. As long as the technical concept of multi-branch zone collection, treatment path selection, adsorption bed switching, desorption regeneration-catalytic treatment and safety interlock described in this invention is still adopted, the corresponding parameter calibration and control implementation methods can be adopted.

Claims

1. An integrated intelligent dust removal and waste gas treatment system for commercial concrete mixing plants, comprising a source collection system (1), a gas transmission system, a dust removal system, a waste gas purification system, a recycling and emission system (7), a monitoring and control system (8), and a safety protection system, characterized in that: The source collection system (1) includes multiple collection branches corresponding to multiple pollutant generating stations of the commercial concrete mixing plant. Each collection branch is equipped with a branch electric regulating valve and a negative pressure sensor, and is connected to the main pipeline through the branch duct. The gas transmission system includes the main pipeline and a variable frequency main fan connected to the main pipeline. The dust removal system includes a cyclone pre-separator and a bag filter unit (3) as a pre-separation unit (2) in sequence along the airflow direction. The exhaust gas purification system includes a wet scrubbing unit (4), a demisting and dehydration unit, an adsorption unit (5), and a catalytic oxidation unit (6). Bypass valves and switching valves are provided between the dust removal system, the wet scrubbing unit (4), the demisting and dehydration unit, the adsorption unit (5), the catalytic oxidation unit (6), and the recovery and emission system (7) to form at least: a dry high-efficiency dust removal path that enters the recovery and emission system (7) after passing through the pre-separation unit (2) and the bag filter unit (3); and a dry high-efficiency dust removal path that enters the recovery and emission system (7) after passing through the pre-separation unit (2), the bag filter unit (3), and the wet scrubbing unit (4). The wet co-purification path of the washing unit (4) and the demisting and dehydration unit enters the recycling and emission system (7); the adsorption purification path of the pre-separation unit (2), bag dust removal unit (3), wet washing unit (4), demisting and dehydration unit and adsorption unit (5) enters the recycling and emission system (7); and the regeneration catalytic treatment path of the concentrated waste gas generated by the offline adsorption bed desorption of the adsorption unit (5) is transported to the catalytic oxidation unit (6); the monitoring and control system (8) is connected to the branch electric regulating valve, negative pressure sensor, variable frequency main fan, bypass valve, switching valve and detection element set in each purification unit respectively; the monitoring and control system (8) adjusts the corresponding branch electric regulating valve according to the real-time negative pressure of each collection branch, and adjusts the variable frequency main fan according to the negative pressure status of multiple working branches; when the adsorption bed reaches the set breakthrough state, the adsorption bed switching is performed, and the concentrated desorption waste gas of the offline adsorption bed is introduced into the catalytic oxidation unit (6) for treatment when the inlet conditions of the catalytic oxidation unit (6) meet the preset safety conditions.

2. The intelligent dust removal and waste gas integrated treatment system for commercial concrete mixing plants according to claim 1, characterized in that, The multiple pollutant generating stations include at least two of the following: powder silo vent, powder metering hopper, aggregate feeding point, mixing host, main building enclosed space, admixture storage tank suction port, vehicle washing platform, and ground dust collection hood; the monitoring and control system (8) adjusts the opening of the electric regulating valve of the corresponding branch according to the production status of each pollutant generating station, the real-time negative pressure of the corresponding collection branch, and the particulate matter concentration, and adjusts the frequency of the variable frequency main fan according to the negative pressure status of multiple working branches, so as to form a zoned negative pressure self-balancing control.

3. The intelligent dust removal and waste gas integrated treatment system for commercial concrete mixing plants according to claim 1, characterized in that, The bag filter unit (3) is a pulse jet bag filter and is equipped with a differential pressure sensor, an outlet particulate matter monitor, a ash hopper level gauge and an ash discharge mechanism. The monitoring and control system (8) executes a cleaning strategy that combines timed cleaning and state-triggered cleaning based on the differential pressure value, differential pressure growth rate and outlet particulate matter concentration of the bag filter unit (3), and outputs a maintenance alarm signal when the differential pressure continues to be higher than the fault threshold or the outlet particulate matter concentration rises abnormally.

4. The intelligent dust removal and waste gas integrated treatment system for commercial concrete mixing plants according to claim 1, characterized in that, The wet scrubbing unit (4) is a spray scrubbing tower structure, including a scrubbing tower body (901) and a spray assembly. The scrubbing tower body (901) is equipped with a pH sensor, a liquid level sensor and a drain valve, and is connected to the circulating water tank of the recovery and discharge system (7). The monitoring and control system (8) adjusts the dosage, replenishment volume and drain valve opening according to the pH value, liquid level and conductivity signals. The adsorption unit (5) adopts a dual-bed structure consisting of at least two adsorption beds. The adsorbent is one or more of granular activated carbon, activated carbon fiber felt or honeycomb activated carbon. Each adsorption bed is equipped with an inlet valve, an outlet valve, a temperature sensor and inlet and outlet total volatile organic compound monitoring points. When the ratio of the total volatile organic compound concentration at the outlet of the adsorption bed to the total volatile organic compound concentration at the inlet reaches the set breakthrough ratio, or when the cumulative running time of the adsorption bed reaches the set threshold, the monitoring and control system (8) performs adsorption bed switching and adjusts the temperature and humidity signals. The switching conditions are corrected; the catalytic oxidation unit (6) includes a heating chamber, a catalytic reaction chamber, a heat exchange chamber, a catalyst carrier, a temperature sensor, an oxygen content sensor, and a lower explosion limit ratio sensor. The catalyst working temperature is 250-420℃; the monitoring and control system (8) allows concentrated desorption waste gas to enter the catalytic oxidation unit (6) when the particulate matter concentration at the inlet of the catalytic oxidation unit (6) is less than 10mg / m³, the combustible gas concentration is less than 25% of the lower explosion limit, and the oxygen content meets the preset conditions. When the lower explosion limit ratio exceeds the limit, the temperature exceeds the limit, or the oxygen content is abnormal, it performs at least one of the following operations: stopping heating, making up air for dilution, closing the catalytic path, and opening the safety bypass; the safety protection system includes one or more of the following: flame arrester, fire damper, explosion relief device, and electrostatic grounding device, and is linked with the monitoring and control system (8) to perform audible and visual alarms, load reduction, bypass switching, or interlock shutdown when equipment failure, parameter over-limit, or safety event is detected.

5. The intelligent dust removal and waste gas integrated treatment system for commercial concrete mixing plants according to claim 1, characterized in that, The monitoring and control system (8) adopts a PLC, industrial touch screen and Internet of Things platform architecture. The Internet of Things platform is used to record operation logs, alarm events, emission data, energy consumption data and maintenance records, and generate environmental compliance reports and equipment health assessment results.

6. The intelligent dust removal and waste gas integrated treatment system for commercial concrete mixing plants according to claim 4, characterized in that, The spray assembly includes a liquid supply rack (921), a control mechanism (93), and a switching mechanism (94); the liquid supply rack (921) is fixedly installed inside the main body of the scrubbing tower (901); the control mechanism (93) includes an electric push rod (931) and a control frame (932), the electric push rod (931) is fixedly installed on the top of the main body of the scrubbing tower (901), and the control frame (932) is fixedly installed at the bottom of the push rod of the electric push rod (931); the switching mechanism (94) includes a switching disk (941), a linkage rod (942), and a spray nozzle (943), the switching disk (941) is rotatably installed at the bottom of the liquid supply rack (921), the linkage rod (942) is rotatably installed at the top of the liquid supply rack (921), the spray nozzle (943) is installed at the bottom of the switching disk (941), and the control frame (932) is in transmission cooperation with the linkage rod (942).

7. The intelligent dust removal and waste gas integrated treatment system for commercial concrete mixing plants according to claim 6, characterized in that, The liquid supply rack (921) is provided with a liquid supply channel (9211), one end of which is connected to an external liquid supply device; the switching disk (941) is provided with a plurality of connecting channels (9411) evenly arranged in the circumferential direction, and each connecting channel (9411) is equipped with a spray nozzle (943) at the bottom, and the spray nozzles (943) corresponding to different connecting channels (9411) have different specifications; in any working position, only the top of one connecting channel (9411) is connected to the other end of the liquid supply channel (9211).

8. The intelligent dust removal and waste gas integrated treatment system for commercial concrete mixing plants according to claim 7, characterized in that, The outer periphery of the linkage rod (942) is provided with a spiral linkage groove (9421), and the control frame (932) is provided with a linkage protrusion (9321) that inserts into the linkage groove (9421). The linkage rod (942) and the rotating shaft of the switching disk (941) are connected by a gear set for transmission, so that the linear displacement of the electric push rod (931) is converted into the rotational displacement of the switching disk (941) through the control frame (932), linkage protrusion (9321), linkage groove (9421), linkage rod (942) and gear set.

9. A method for intelligent dust removal and exhaust gas treatment control of a commercial concrete mixing plant, applied to a treatment device including multiple collection branches, a pre-separation unit (2), a bag filter unit (3), a wet scrubbing unit (4), a demisting and dehydration unit, an adsorption unit (5), a catalytic oxidation unit (6), and a recovery and emission system (7), characterized in that, Includes the following steps: S1. Collect at least some of the following signals from each collection branch and each purification unit: particulate matter concentration, total volatile organic compound concentration, temperature, humidity, oxygen content, lower explosive limit ratio, differential pressure, negative pressure, liquid level, pH, current, vibration, and valve position signals. S2. Identify the current pollutant type and pollution load level based on particulate matter concentration, total volatile organic compound concentration, temperature and humidity, and the production conditions of the ready-mixed concrete plant; S3. Based on the identification results, select the current processing path from the dry high-efficiency dust removal path, the wet synergistic purification path, and the adsorption purification path; S4. Under the selected processing path, adjust the opening of the branch electric regulating valve, the frequency of the variable frequency main fan, the spray status, the dust removal status, and the working status of the adsorption bed. S5. When the adsorption bed reaches the set breakthrough state, the adsorption bed is switched and the offline adsorption bed is desorbed and regenerated. The concentrated desorbed waste gas generated is transported to the catalytic oxidation unit (6) when the inlet conditions of the catalytic oxidation meet the preset safety conditions. S6. Based on emission test results and equipment status, maintain the current operating status, upgrade the treatment mode, perform bypass switching, or interlock shutdown.

10. The control method according to claim 9, characterized in that: The pollution load levels include at least light load, medium load, and heavy load; when the pollutants are mainly particulate matter and the total volatile organic compound concentration is lower than the corresponding set threshold, a dry high-efficiency dust removal path is selected; when there is a need to treat high humidity, odor, or soluble gases, a wet synergistic purification path is selected; when the gas after dust removal, demisting, and dehydration has a need for deep purification of total volatile organic compounds, an adsorption purification path is selected. In step S4, the operation requirements of the corresponding collection branch are determined according to the production status of each pollutant generating station, the electric regulating valve of the branch is adjusted according to the real-time negative pressure of the corresponding negative pressure sensor, and the frequency of the variable frequency main fan is adjusted according to the negative pressure status of multiple working branches; at the same time, the cleaning timing is determined according to the differential pressure value, differential pressure growth rate and outlet particulate matter concentration of the bag filter unit (3). In step S5, when the ratio of the total volatile organic compound concentration at the outlet of the adsorption bed to the total volatile organic compound concentration at the inlet reaches the set breakthrough ratio, or when the cumulative running time reaches the set threshold, the current adsorption bed is switched to offline state and put into standby adsorption bed; hot air or inert gas is introduced into the offline adsorption bed for desorption, and the resulting concentrated desorbed waste gas is transported to the catalytic oxidation unit (6); when the combustible gas concentration at the inlet of the catalytic oxidation unit (6) reaches the warning threshold, the make-up air dilution and heating are stopped first. When it still cannot be restored to the safe range, the catalytic path is closed and the safety bypass is opened, so that the abnormal gas returns to the front end for treatment or enters the safety treatment branch.

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