Centrifugal and gravity sedimentation multi-stage combined oil-water separation device for water pollution treatment

Abstract

The present application relates to the field of water pollution control and treatment technology, and discloses a centrifugal and gravity settling multi-stage combined oil-water separation device for water pollution treatment, which comprises a centrifuge, a buffer and a settling tank connected in sequence, and a control component for coordinated control of operation of each pipeline; the control component is internally provided with multiple function modules of device topology binding, centrifugal separation state identification, buffer despinning determination, settling interface estimation, multi-stage on-off window generation, operation write-back calibration and abnormal lockout recovery; by identifying the centrifugal state, determining the despinning state, estimating the oil-water interface migration state and generating the multi-stage on-off window, the control device sequentially completes centrifugal separation, energy dissipation and despinning, static settling, oil discharge and water discharge, while combining operation record correction control parameters, and executing lockout recovery in abnormal state. The problems of easy disturbance of the settling interface of the centrifugal water flow, poor coordination of each treatment stage and insufficient safety in abnormal operation in the existing device are solved.

Description

Technical Field

[0001] This invention relates to the field of water pollution control and treatment technology, specifically to a multi-stage combined oil-water separation device using centrifugal and gravity sedimentation for water pollution treatment. Background Technology

[0002] Existing oily wastewater treatment devices typically employ a combination of centrifugal separation and gravity sedimentation. During operation, the oily wastewater first enters a centrifuge through a feed pipe. The centrifuge's high-speed rotation creates a centrifugal force field, causing the denser aqueous phase to migrate outwards and the less dense oil phase to accumulate towards the center. The separated oil phase is discharged through an oil outlet pipe, while the aqueous phase containing residual oil droplets is transported to a settling tank through a water outlet pipe. Once in the settling tank, the aqueous phase undergoes static settling due to the density difference between oil and water, causing the residual oil droplets to gradually rise and form an oil layer. Subsequently, the oil phase and the treated aqueous phase are discharged through the oil outlet pipe at the top of the settling tank and the water outlet pipe at the bottom, respectively, thus completing the multi-stage separation and treatment of the oily wastewater.

[0003] However, the water discharged from centrifuges typically exhibits high flow velocities, residual swirling, and flow pulsations. If it directly enters the settling tank, it can easily disturb the already formed oil-water stratification interface, causing tiny oil droplets to redisperse and affecting the subsequent gravity settling process. Furthermore, existing systems often lack continuous correlation and judgment regarding the centrifugal separation state, buffer deswirl state, and changes in the oil-water interface in the settling tank. The feed, oil discharge, and drainage pipelines are mostly controlled by fixed timing sequences or single detection signals, which can easily lead to interference between feed, oil discharge, and drainage actions. In addition, when the processing load, centrifuge operating status, or oil-water composition changes, existing control parameters are difficult to correct in a timely manner. When anomalies such as centrifugal instability, buffer re-disturbance, uncertain interface states, or actuator malfunctions occur, there is a lack of interlocking and recovery mechanisms adapted to the multi-stage separation process, affecting the stability and safety of the system operation. Summary of the Invention

[0004] This invention provides a multi-stage combined centrifugal and gravity sedimentation oil-water separation device for water pollution treatment, which solves the problems mentioned in the background art.

[0005] This invention provides the following technical solution: a multi-stage combined oil-water separation device using centrifugation and gravity sedimentation for water pollution treatment, comprising a centrifuge, a centrifuge feed pipe and a centrifuge oil outlet pipe installed at the top of the centrifuge, a centrifuge water outlet pipe installed at the bottom of the centrifuge, a buffer and a sedimentation tank arranged on one side of the bottom of the centrifuge, the inlet of the buffer being connected to the centrifuge water outlet pipe, the outlet of the buffer being connected to a buffer water outlet pipe, a sedimentation feed pipe installed on the side wall of the sedimentation tank being connected to the buffer water outlet pipe, a sedimentation oil outlet pipe and a sedimentation water outlet pipe being installed at the top and bottom of the sedimentation tank respectively, and a control component being arranged on one side of the sedimentation tank;

[0006] The control unit includes a device topology binding module, a centrifuge separation status identification module, a buffer despinning completion determination module, a settling tank interface migration estimation module, a multi-level on / off window generation module, a running writeback calibration module, and an abnormal lockout recovery module.

[0007] The device topology binding module is used to establish a fixed connection between the centrifuge, buffer, and settling tank, and output control address information; the centrifuge separation status identification module is used to generate centrifuge separation status information based on the centrifuge's operating status; the buffer despinning completion determination module is used to generate buffer despinning completion status information based on the centrifuge separation status information and the buffer status; the settling tank interface migration estimation module is used to generate settling tank interface status information based on the buffer despinning completion status information; the multi-level on / off window generation module is used to control the operating status of the centrifuge feed pipe, centrifuge oil outlet pipe, centrifuge water outlet pipe, settling oil outlet pipe, and settling water outlet pipe based on the centrifuge separation status information, buffer despinning completion status information, and settling tank interface status information; the operation write-back calibration module is used to correct operating parameters; and the abnormal lockout recovery module is used to control the device to enter the lockout recovery process based on the abnormal status.

[0008] The present invention has the following beneficial effects:

[0009] 1. This invention installs a buffer between the centrifuge and the settling tank, allowing the water discharged from the centrifuge to undergo energy dissipation, deceleration, and residual vortex attenuation before entering the settling tank. The buffer's devortex attenuation determination module, combined with the centrifuge's separation state, processing flow rate, and water flow pulsation, determines whether the water flow has reached a suitable settling feed state. This reduces the impact of high-speed and pulsating water flow on the oil-water stratification interface inside the settling tank, prevents the already accumulated oil droplets from dispersing again, and provides a relatively stable flow environment for the stable floating and gravity separation of residual oil droplets.

[0010] 2. This invention uses a device topology binding module, a centrifuge separation state identification module, a buffer despinning completion determination module, a settling tank interface migration estimation module, and a multi-level on / off window generation module to correlate and control the operating states of the centrifuge, buffer, and settling tank. It generates pipeline on / off windows in the order of centrifugal acceleration, controlled feeding, buffer attenuation, settling and settling, settling and oil discharge, and settling and water drainage, so that feeding, oil discharge, and drainage actions are executed after the corresponding state conditions are met. This helps to avoid mutual interference between different processing stages and achieves coordinated control of the timing of oil discharge and drainage from the settling tank without the need for additional oil-water interface detection components.

[0011] 3. This invention records the centrifugal effluent status, buffer deswirl status, sedimentation oil discharge status, and sedimentation drainage status of each batch through a write-back calibration module. Based on the operation records, it corrects the residual oil load parameters and oil discharge control parameters, enabling the control process to adapt to changes in processing flow rate, oil load, and equipment operating status. Simultaneously, the abnormal interlock recovery module classifies and handles abnormalities such as topological anomalies, centrifugal instability, buffer re-disturbance, interface uncertainty, and actuator misalignment, promptly shutting down relevant feed, oil discharge, or drainage pipelines, and executing the emptying, trial discharge, reset, or restart process according to preset conditions, thereby improving the reliability of the device during continuous operation and the safety under abnormal conditions. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0013] Figure 2 This is a schematic diagram of the centrifuge structure of the present invention;

[0014] Figure 3 This is a schematic diagram of the buffer and settling tank structure of the present invention;

[0015] Figure 4 This is a flowchart of the overall module of the built-in control system of the present invention;

[0016] Figure 5 This is a flowchart of the centrifuge separation state recognition process of the present invention;

[0017] Figure 6 This is a flowchart illustrating the despinning completion determination process of the buffer according to the present invention.

[0018] Figure 7 This is a flowchart illustrating the process of generating the on / off window for the settling tank according to the present invention.

[0019] Figure 8 This is a flowchart of the abnormal lockout recovery process of the present invention.

[0020] In the diagram: 1. Centrifuge; 11. Centrifuge feed pipe; 12. Centrifuge oil outlet pipe; 13. Centrifuge water outlet pipe; 2. Buffer; 21. Buffer water outlet pipe; 3. Settling tank; 31. Settling feed pipe; 32. Settling oil outlet pipe; 33. Settling water outlet pipe; 4. Control components. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. In addition, the forms of the various structures described in the following embodiments are merely illustrative. The multi-stage combined centrifugal and gravity sedimentation oil-water separation device for water pollution treatment involved in the present invention is not limited to the structures described in the following embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see Figures 1-3 The multi-stage combined centrifugal and gravity sedimentation oil-water separation device for water pollution treatment shown includes a centrifuge 1 for centrifugal separation of oily wastewater, using centrifugal force to rapidly separate oil and water into layers. The centrifuge 1 has a centrifugal feed pipe 11 and a centrifugal oil outlet pipe 12 installed at its top. The centrifugal feed pipe 11 introduces the oily wastewater into the centrifuge 1 for separation, and the centrifugal oil outlet pipe 12 discharges the separated light phase oil from the top. The centrifuge 1 has a centrifugal water outlet pipe 13 installed at its bottom, discharging the separated heavy phase water from the bottom. A buffer 2 and a sedimentation tank 3 are installed on one side of the bottom of the centrifuge 1. The buffer 2 dissipates energy and slows down the water flow discharged from the centrifugal water outlet pipe 13, reducing the flow velocity and eliminating residual vortices. The inlet of the buffer 2... The buffer tank 2 is connected to the centrifugal outlet pipe 13. The outlet of the buffer tank 2 is equipped with a buffer outlet pipe 21. The side wall of the settling tank 3 is equipped with a settling feed pipe 31, which is connected to the buffer outlet pipe 21. The settling feed pipe 31 is used to introduce the buffered water flow into the settling tank 3 for gravity settling separation. The settling tank 3 is used to perform deep gravity settling separation of residual tiny oil droplets in the water flow by utilizing the density difference between oil and water. The top and bottom of the settling tank 3 are respectively equipped with a settling oil outlet pipe 32 and a settling water outlet pipe 33. The settling oil outlet pipe 32 is used to discharge the floating oil separated by gravity settling from the top of the settling tank 3. The settling water outlet pipe 33 is used to discharge the purified water after gravity settling from the bottom of the settling tank 3. A control component 4 is provided on one side of the settling tank 3 to control the coordinated operation of each component.

[0023] During operation, oily wastewater enters the centrifuge 1 from the top through the centrifugal feed pipe 11. The centrifuge 1 rotates at high speed, generating a centrifugal force field. Under the action of centrifugal force, the denser water phase is thrown to the outer layer, while the less dense oil phase gathers in the center. The separated oil is discharged from the top through the centrifugal oil outlet pipe 12, and the separated water phase is discharged from the bottom through the centrifugal water outlet pipe 13 and enters the buffer 2. The buffer 2 dissipates energy and slows down the high-speed water flow, eliminates residual swirling flow, and reduces the flow velocity to a suitable range for gravity settling. Afterward, the water flows smoothly into the settling tank 3 through the buffer outlet pipe 21 and the settling feed pipe 31. Inside the settling tank 3, the water flows slowly, and the remaining tiny oil droplets gradually float to the surface under gravity to form a floating oil layer. The floating oil is discharged from the top through the settling oil outlet pipe 32, and the purified water is discharged from the bottom through the settling water outlet pipe 33. Throughout the entire operation, the control unit 4 coordinates and controls the operation status of each component and the opening and closing of the liquid outlet pipe, thereby completing the multi-stage combined oil-water separation operation of centrifugation and gravity settling of oily wastewater.

[0024] refer to Figures 4-8 The system built into the control component 4 consists of a device topology binding module, a centrifuge separation state identification module, a buffer despinning completion determination module, a settling tank interface migration estimation module, a multi-level on / off window generation module, a running write-back calibration module, and an anomaly lockout recovery module. Within the control cycle, the system sequentially completes structural identity confirmation, centrifuge state identification, buffer state calculation, settling interface estimation, on / off window generation, result write-back, and anomaly handling.

[0025] The device topology binding module is used to fix the built-in system of the control component 4 to the series separation path composed of centrifuge 1, buffer 2, and settling tank 3; save the connection relationship between centrifuge 1 and buffer 2, the connection relationship between buffer 2 and settling tank 3, the phase attributes of centrifuge oil outlet pipe 12 and centrifuge water outlet pipe 13, the vertical position attributes of settling oil outlet pipe 32 and settling water outlet pipe 33, and save the control address, position feedback address and safety initial state of each existing actuator.

[0026] The device topology binding module outputs a unified data address table to the centrifuge separation state identification module, outputs the effective volume of buffer 2 and the path delay from centrifuge outlet pipe 13 to sedimentation feed pipe 31 to the buffer despinning completion judgment module, and outputs the effective volume of sedimentation tank 3, the effective cross-sectional area of ​​sedimentation tank 3, and the calibrated value of the oil discharge volume corresponding to the unit opening time of sedimentation oil outlet pipe 32 to the sedimentation tank interface migration estimation module.

[0027] After the control unit 4 is powered on, the device topology binding module first reads the internal read-only parameter area. The read-only parameter area records at least the equipment number, the rated speed of centrifuge 1, the rated processing flow of centrifuge 1, the effective volume of buffer 2, the effective volume of settling tank 3, the effective cross-sectional area of ​​settling tank 3, the control address of centrifuge oil outlet pipe 12, the control address of centrifuge water outlet pipe 13, the control address of settling oil outlet pipe 32, and the control address of settling water outlet pipe 33. Each control address also records the expected normally closed or normally open state. The control unit 4 performs a step-by-step comparison between the control output and the position feedback.

[0028] The device topology binding module uses a fixed sequence of verification. The first step confirms that the centrifuge 1 is in a stopped state; the second step confirms that the centrifuge feed pipe 11 is in a closed state; the third step confirms that the centrifuge oil outlet pipe 12, centrifuge water outlet pipe 13, sedimentation oil outlet pipe 32, and sedimentation water outlet pipe 33 are all in a safe initial state; the fourth step confirms that the effective volume of the buffer 2 and the effective volume of the sedimentation tank 3 have been written; the fifth step confirms that the phase attribute of the sedimentation oil outlet pipe 32 is the oil phase outlet and the phase attribute of the sedimentation water outlet pipe 33 is the water phase outlet. If any control address is missing, the position feedback is inconsistent, or the phase attribute conflicts, the device topology binding module will not output an operating permission and will send the fault code to the abnormal interlock recovery module.

[0029] The device topology binding module also generates a topology identity word, which is composed of the device number, the component number sequence "1-13-2-21-31-3-32-33", and the control address verification value. The control unit 4 recalculates the topology identity word each time it starts. Only when the current topology identity word matches the internal permission result is the subsequent module allowed to run. This control method makes the control logic dependent on the fixed sequence of centrifugal water outlet pipe 13 entering the settling tank 3 through buffer 2, buffer water outlet pipe 21, and settling feed pipe 31.

[0030] The centrifuge separation status identification module is used to combine the speed, operating current, start / stop status of the centrifuge 1 driver with the control status of the centrifuge feed pipe 11, the centrifuge oil outlet pipe 12, and the centrifuge water outlet pipe 13 to form the centrifuge 1 separation status word.

[0031] The centrifuge 1 separation status is divided into shutdown state, acceleration state, stable separation state, water pulsation state, oil release state, and unstable state. The centrifuge separation status identification module generates the current processing flow rate estimate in the stable separation state, generates the centrifuge water pulsation index in the water pulsation state, and generates the residual oil load coefficient at the end of each control window. The current processing flow rate estimate, centrifuge water pulsation index, and residual oil load coefficient are sent to the buffer deswirl completion judgment module and the settling tank interface migration estimation module.

[0032] The control unit 4 reads the speed and operating current of the centrifuge 1 driver with a sampling period of 100 milliseconds. With a control window of 5 seconds, after the centrifuge 1 is started, when the actual speed does not enter the range of 98.5% to 101.5% of the rated speed, the centrifuge 1 separation status word remains in the speed-up state.

[0033] When the actual rotational speed enters the range of 98.5% to 101.5% of the rated speed and is maintained continuously for two control windows, and the centrifugal effluent pulsation index is not greater than 0.06, the centrifuge 1 separation status word changes to stable separation state. After the centrifugal feed pipe 11 is opened, when the working current shows periodic deviation or the rotational speed shows repeated decline, and the centrifugal effluent pipe 13 is in the open state, the centrifuge 1 separation status word changes to effluent pulsation state.

[0034] When the centrifuge oil outlet pipe 12 is opened, the centrifuge separation status identification module switches the centrifuge 1 separation status word to oil release status and suspends the update of residual oil load coefficient to prevent the oil phase release action from being identified as a sudden change in oil load.

[0035] The centrifugal effluent pulsation index is used to describe the load fluctuations and speed fluctuations of centrifuge 1 within the current control window. The centrifuge separation state identification module first performs median filtering on the speed and operating current, taking 5 sampling points in the median filtering window, and then calculates the centrifugal effluent pulsation index:

[0036]

[0037] Where P r Let I be the centrifugal effluent pulsation index for the r-th control window, M be the number of sampling points within the control window, and I be the index of the centrifugal effluent. m Let m be the operating current at the m-th sampling point. Let ε be the average operating current of the i-th control window. I For the current to prevent zero constant, N m Let m be the rotational speed at the m-th sampling point. Let ε be the average rotational speed of the r-th control window. N is the rotational speed zero-prevention constant, and μ is the rotational speed fluctuation weight.

[0038] The estimated current processing flow rate is obtained by multiplying the rated processing flow rate of centrifuge 1 stored in the device topology binding module by the ratio of the current operating current to the calibrated operating current, and then corrected according to the actual opening duty cycle of the centrifugal feed pipe 11.

[0039] The residual oil load coefficient is generated by segmented mapping. The first calibration interval is used when the centrifugal effluent pulsation index is not greater than 0.06; the second calibration interval is used when the centrifugal effluent pulsation index is greater than 0.06 but not greater than 0.12; and the third calibration interval is used when the centrifugal effluent pulsation index is greater than 0.12. The residual oil load coefficient in the three calibration intervals is corrected by the operation write-back calibration module respectively.

[0040] The buffer deswirl completion determination module is used to calculate the time point when the pulsating water flow discharged from the centrifuge outlet pipe 13 completes energy dissipation and swirl decay in the buffer 2 based on the centrifuge 1 separation status word, the current processing flow estimate, the centrifuge outlet pulsation index, the effective volume of the buffer 2 and the path delay.

[0041] The buffer despinning completion determination module outputs the buffer 2 despinning completion status word, which is divided into non-accepted state, filled state, attenuated state, despinning completion state, and re-disturbance dynamic, and is sent to the settling tank interface migration estimation module and the multi-level on / off window generation module.

[0042] When the centrifuge outlet pipe 13 changes from closed to open, the buffer despinning completion judgment module records the starting point of this filling and sets the buffer 2 despinning completion status word to the filling state. When the centrifuge 1 separation status word is in the stable separation state and the centrifuge outlet pulsation index continues to decrease, the buffer despinning completion judgment module switches to the decay state.

[0043] The buffer deswirl completion determination module calculates the deswirl completion amount using the current processing flow rate estimate, the effective volume of buffer 2, and the effective time period accumulated from the start of this filling. During the calculation, the buffer deswirl completion determination module excludes the period when the centrifugal outlet pipe 13 is closed, and only accumulates the time period when the centrifugal outlet pipe 13 is open and the centrifuge 1 separation state is in a stable separation state or the outlet pulse is dynamic.

[0044] The amount of desiccation completed is specifically expressed as follows:

[0045]

[0046] Where D r Q represents the derotation completion amount for the r-th control window. r T is the estimated current processing flow rate for the r-th control window. r V represents the cumulative valid time period from the starting point of this charge to the r-th control window. b P is the effective volume of buffer 2. b ε is the centrifugal effluent pulsation index corresponding to the starting point of this charge. P It is the zero constant for pulsation prevention.

[0047] When the amount of deswirl completion is not less than 0.75 and is maintained for two consecutive control windows, the deswirl completion status word of buffer 2 changes to the deswirl completion state. After the deswirl completion state is formed, if the centrifugal effluent pulsation index exceeds 0.12 again, or the centrifugal feed pipe 11 switches between opening and closing twice within a single control window, the deswirl completion status word of buffer 2 immediately changes to the re-disturbance dynamic state. The multi-level on / off window generation module suspends new feed windows until the amount of deswirl completion meets the judgment conditions again.

[0048] The settling tank interface migration estimation module is used to estimate the amount of oil layer thickness migration in the settling tank 3 based on the current processing flow rate estimate, residual oil load coefficient, buffer 2 deswirl completion status word, cumulative opening time of settling oil outlet pipe 32, and effective cross-sectional area of ​​settling tank 3, without setting up new oil-water interface detection components.

[0049] The settling tank interface migration estimation module outputs the settling tank 3 interface status word, which is divided into acceptance state, static state, oil discharge preparation state, oil discharge state, drainage preparation state, drainage state, and interface uncertainty state, and is directly read by the multi-level on / off window generation module.

[0050] When the despinning completion status word of the buffer 2 is in the despinning completion state, the settling tank interface migration estimation module includes the current processing flow rate estimation value into the effective acceptance capacity of the settling tank 3.

[0051] During the period when the despinning completion status word of the buffer 2 is in the filling state, decay state, or re-disturbance dynamic state, the settling tank interface migration estimation module records the flow rate entering the settling feed pipe 31 as the disturbance amount. The disturbance amount is not used to increase the drainage capacity and keeps the settling tank 3 interface status word in a static state for a settling recovery period. The settling recovery period is obtained by dividing the effective volume of the settling tank 3 by the current processing flow rate estimation value and is limited to the shortest and longest period set during the device commissioning phase.

[0052] The estimated oil layer thickness inside settling tank 3 is specifically expressed as follows:

[0053]

[0054] Where H r Q is the estimated oil layer thickness at the end of the r-th control window. h Δt is the estimated current processing flow rate for the h-th control window. h R is the duration for which the effective acceptance rate is counted in the h-th control window. h κ is the residual oil load coefficient for the h-th control window. o U is the calibration value of the oil discharge volume corresponding to the 32-unit opening period of the settling oil pipe. r For the cumulative opening time of the settlement oil outlet pipe 32 up to the r-th control window, A sThe effective cross-sectional area of ​​settling tank 3.

[0055] When the estimated oil layer thickness reaches the oil discharge start thickness, the status word of interface 3 of the settling tank changes to the oil discharge preparation state; when the estimated oil layer thickness falls back to the oil discharge stop thickness, the status word of interface 3 of the settling tank changes to the drainage preparation state.

[0056] The oil discharge start thickness can be set to 12% of the effective liquid depth of settling tank 3, and the oil discharge stop thickness can be set to 5% of the effective liquid depth of settling tank 3. If three consecutive control windows show negative estimates, the settling tank interface migration estimation module clamps the oil layer thickness estimate to zero and converts the interface status word of settling tank 3 to an interface uncertain state, which is then handed over to the operation write-back calibration module to correct the oil discharge volume calibration value corresponding to the unit opening time of settling oil pipe 32.

[0057] The multi-level on / off window generation module is used to generate interlocked on / off windows for centrifugal feed pipe 11, centrifugal oil outlet pipe 12, centrifugal water outlet pipe 13, sedimentation oil outlet pipe 32, and sedimentation water outlet pipe 33 based on the separation status word of centrifuge 1, the despinning completion status word of buffer 2, and the interface status word of sedimentation tank 3.

[0058] The multi-level on / off window generation module adopts a fixed phase sequence centrifugal acceleration window, a controlled feeding window, a buffer attenuation window, a settling and settling window, a settling and oil discharge window, and a settling and drainage window. Each on / off window must be confirmed by the previous status word before it can be entered.

[0059] Within the centrifugal acceleration window, the centrifugal feed pipe 11 is closed, the centrifugal oil outlet pipe 12 is closed, the centrifugal water outlet pipe 13 maintains the original safe state of the control component 4, the sedimentation oil outlet pipe 32 is closed, and the sedimentation water outlet pipe 33 is closed.

[0060] After the centrifuge 1 changes from a separation state to a stable separation state, it enters the controlled feeding window. The controlled feeding window initially adopts a 30% duty cycle. The control unit 4 uses one buffer 2 nominal residence time as a cycle. First, the centrifuge feed pipe 11 is opened, and then the centrifuge outlet pipe 13 is opened. After the buffer 2 deswirl completion state changes to a deswirl completion state, the opening duty cycle of the centrifuge feed pipe 11 is increased in 10% increments. After each increase, at least two control windows are maintained.

[0061] When the state word of the despinning of the buffer 2 changes to the re-disturbance dynamic, the system enters the buffer attenuation window. In the buffer attenuation window, the centrifugal feed pipe 11 is closed, the centrifuge 1 maintains the rated speed, the centrifugal water outlet pipe 13 remains open until the water inside the centrifuge 1 is drained, and the sedimentation oil outlet pipe 32 and the sedimentation water outlet pipe 33 are both closed.

[0062] After the despinning completion status word of the buffer 2 is changed back to the despinning completion state, it enters the settling and settling window. In the settling and settling window, the centrifugal feed pipe 11 is kept closed, and the settling oil outlet pipe 32 and the settling water outlet pipe 33 are both closed, and this continues for a settling recovery period.

[0063] After the status word of the settling tank 3 interface changes to the oil discharge preparation state, it enters the settling oil discharge window. In the settling oil discharge window, the centrifugal feed pipe 11 and the settling water outlet pipe 33 are closed, and the settling oil outlet pipe 32 is opened.

[0064] The settling oil outlet pipe 32 operates in a pulse mode. Each opening period is obtained by subtracting the current estimated oil layer thickness from the thickness at which oil discharge stops, and then dividing by the oil layer descent corresponding to the unit opening period of the settling oil outlet pipe 32. The single opening period is limited to 3 to 20 seconds. After each pulse ends, the settling oil outlet pipe 32 is closed and held for 5 seconds, during which the estimated oil layer thickness is recalculated by the settling tank interface migration estimation module.

[0065] When the status word of the settling tank 3 interface changes to the drainage preparation state and the status word of the buffer 2 despinning completion state remains in the despinning completion state, the system enters the settling drainage window. In the settling drainage window, the settling oil outlet pipe 32 is closed and the settling water outlet pipe 33 is opened.

[0066] If the estimated oil layer thickness reaches the oil discharge start thickness again, the settling water outlet pipe 33 will be immediately closed, and the process will return to the settling oil discharge window; if the centrifuge 1 separation status word changes to an unstable state, the settling water outlet pipe 33 will be closed, and the process will enter the abnormal lockout recovery module.

[0067] The operation writeback calibration module is used to write the centrifugal effluent pulsation index, the current processing flow rate estimate, the opening time of the sedimentation oil outlet pipe 32, the opening time of the sedimentation water outlet pipe 33, and the manually entered effluent oil content detection results into the batch record for each batch, and to correct the residual oil load coefficient segment table and the oil discharge volume calibration value corresponding to the unit opening time of the sedimentation oil outlet pipe 32.

[0068] After each settling and drainage window ends, the write-back calibration module generates a batch number. The batch record includes the average centrifugal effluent pulsation index, the maximum centrifugal effluent pulsation index, the time period taken for buffer 2 to complete deswirl, the starting point of the oil layer thickness estimate, the ending point of the oil layer thickness estimate, the cumulative opening time of the settling oil outlet pipe 32, and the cumulative opening time of the settling water outlet pipe 33.

[0069] After the operator enters the oil content test results of the batch of effluent into the human-machine interface of control component 4, the write-back calibration module is run to match the test results with the current residual oil load coefficient segment table.

[0070] When the test result exceeds the set control limit, the write-back calibration module will only correct the residual oil load coefficient of the pulsation interval to which this batch belongs, with the correction range being 5% of the original value, and the oil discharge start thickness of the next batch will be reduced by 1% of the effective liquid depth of settling tank 3.

[0071] When the test results are within the control limit for three consecutive batches, the write-back calibration module keeps the residual oil load coefficient unchanged and only allows the oil discharge start thickness to recover to the initial set value in steps of 0.5% of the effective liquid depth of settling tank 3.

[0072] The oil discharge volume calibration value corresponding to the 32-unit opening period of the settling oil pipe is only corrected when the estimated oil layer thickness is clamped to zero for three consecutive control windows, and the correction range is limited to 3% of the original value each time.

[0073] The operation write-back calibration module saves the records of the most recent 30 batches. When a new batch starts, the operation write-back calibration module extracts the 5 most recent batches that are consistent with the current centrifugal effluent pulsation index range and calculates the median as the operating reference value of the residual oil load coefficient.

[0074] The abnormal lockout recovery module is used to receive the abnormal codes output by the device topology binding module, centrifuge separation status identification module, buffer despinning completion determination module, settling tank interface migration estimation module, and multi-level on / off window generation module, and to perform hierarchical lockout according to the source of the abnormality.

[0075] The abnormal lockout recovery module classifies abnormalities into five categories: topological abnormalities, centrifugal instability, buffer re-disturbance timeout, interface uncertainty, and actuator incompleteness. Each category has a fixed shutdown sequence and recovery conditions.

[0076] When the topological anomaly occurs, the control unit 4 prohibits the centrifuge 1 from starting, shuts down the centrifuge feed pipe 11, centrifuge oil outlet pipe 12, centrifuge water outlet pipe 13, sedimentation oil outlet pipe 32, and sedimentation water outlet pipe 33, and requires manual confirmation of the equipment number and control address.

[0077] When centrifugal instability occurs, the abnormal lockout recovery module first closes the centrifugal feed pipe 11, then closes the sedimentation outlet pipe 33, and the centrifuge 1 maintains its rated speed for 10 seconds to drain the internal water, and then stops the centrifuge 1.

[0078] When the buffer re-interference timeout occurs, the abnormal lockout recovery module closes the centrifugal feed pipe 11 and keeps the centrifugal outlet pipe 13 open. If the de-spinning state is not completed after the timer reaches the nominal residence period of two buffers 2, the abnormal lockout recovery module closes the centrifugal outlet pipe 13 and enters the manual reset state.

[0079] When the interface is uncertain, the settling water outlet pipe 33 remains closed, and the settling oil outlet pipe 32 performs a 5-second test oil discharge pulse. After the test oil discharge pulse ends, the settling tank interface migration estimation module recalculates the estimated oil layer thickness. When the interface status word of the settling tank 3 is still in the interface uncertainty state, the system keeps the settling oil outlet pipe 32 and the settling water outlet pipe 33 closed and prompts the user to enter the manual inspection results.

[0080] When the actuator fails to be in position, the abnormal interlock recovery module freezes the current on / off window, closes all actuators that are allowed to be closed, records the time when the control command is issued, the time when the position feedback is received, and the status of missing feedback. After manual reset, it restarts from the centrifugal acceleration window and does not continue from the abnormal occurrence window.

[0081] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0082] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-stage combined centrifugal and gravity sedimentation oil-water separation device for water pollution treatment, comprising a centrifuge (1), wherein a centrifuge feed pipe (11) and a centrifuge oil outlet pipe (12) are installed at the top of the centrifuge (1), and a centrifuge water outlet pipe (13) is installed at the bottom of the centrifuge (1), characterized in that: A buffer (2) and a settling tank (3) are provided on one side of the bottom of the centrifuge (1). The inlet of the buffer (2) is connected to the centrifuge outlet pipe (13). A buffer outlet pipe (21) is installed at the outlet of the buffer (2). A settling feed pipe (31) is installed on the side wall of the settling tank (3). The settling feed pipe (31) is connected to the buffer outlet pipe (21). A settling oil outlet pipe (32) and a settling water outlet pipe (33) are installed at the top and bottom of the settling tank (3), respectively. A control component (4) is provided on one side of the settling tank (3). The control unit (4) has a built-in device topology binding module, centrifuge separation status identification module, buffer despinning completion determination module, settling tank interface migration estimation module, multi-level on / off window generation module, operation write-back calibration module and abnormal lockout recovery module. The device topology binding module is used to establish a fixed connection relationship between the centrifuge (1), the buffer (2) and the settling tank (3), and output control address information; the centrifuge separation status identification module is used to generate centrifuge (1) separation status information according to the operating status of the centrifuge (1); the buffer deswirl completion determination module is used to generate buffer (2) deswirl completion status information according to the centrifuge (1) separation status information and the buffer (2) status; the settling tank interface migration estimation module is used to generate settling tank (3) interface status information according to the buffer (2) deswirl completion status information; the multi-level on / off window generation module is used to control the operating status of the centrifuge feed pipe (11), centrifuge oil outlet pipe (12), centrifuge water outlet pipe (13), settling oil outlet pipe (32) and settling water outlet pipe (33) according to the centrifuge (1) separation status information, buffer (2) deswirl completion status information and settling tank (3) interface status information; the operation write-back calibration module is used to correct the operating parameters; the abnormal lockout recovery module is used to control the device to enter the lockout recovery process according to the abnormal status.

2. The multi-stage combined centrifugal and gravity sedimentation oil-water separation device for water pollution treatment according to claim 1, characterized in that: The device topology binding module stores the connection relationship between centrifuge (1), buffer (2), and settling tank (3), and stores the control address and feedback address corresponding to centrifuge oil outlet pipe (12), centrifuge water outlet pipe (13), settling oil outlet pipe (32), and settling water outlet pipe (33). The control component (4) establishes the device operation permission status by reading the control address and feedback address.

3. The multi-stage combined centrifugal and gravity sedimentation oil-water separator for water pollution treatment according to claim 1, characterized in that: The centrifuge separation state identification module is connected to the centrifuge (1) drive control terminal to obtain the centrifuge (1) speed, working current and start-stop state, and generate shutdown state, speed-up state, stable separation state, water pulse dynamics, oil release state and unstable state based on the obtained data.

4. The multi-stage combined centrifugal and gravity sedimentation oil-water separator for water pollution treatment according to claim 1, characterized in that: The buffer despinning completion determination module is connected to the device topology binding module. The buffer despinning completion determination module generates the unaccepted state, the filled state, the decay state, the despinning completion state and the re-disturbance dynamic based on the effective volume of the buffer (2), the data output by the centrifuge separation state identification module and the opening state of the centrifuge outlet pipe (13).

5. The multi-stage combined centrifugal and gravity sedimentation oil-water separator for water pollution treatment according to claim 1, characterized in that: The settling tank interface migration estimation module is connected to the buffer despinning completion judgment module. The settling tank interface migration estimation module generates the receiving state, static state, oil discharge preparation state, oil discharge state, drainage preparation state, drainage state and interface uncertainty state based on the current processing flow rate estimation value, residual oil load coefficient, cumulative opening time of settling oil outlet pipe (32) and effective cross-sectional area of ​​settling tank (3).

6. The multi-stage combined centrifugal and gravity sedimentation oil-water separator for water pollution treatment according to claim 1, characterized in that: The multi-level on / off window generation module generates a control flow in the order of centrifugal acceleration window, controlled feed window, buffer attenuation window, settling and settling window, settling and oil discharge window, and settling and drainage window. It controls the opening or closing of each pipeline based on the status information output by the centrifuge separation status identification module, the buffer despinning completion judgment module, and the settling tank interface migration estimation module.

7. The multi-stage combined centrifugal and gravity sedimentation oil-water separator for water pollution treatment according to claim 1, characterized in that: The operation write-back calibration module is used to establish batch operation records. The batch operation records include the operation status of the centrifugal water outlet pipe (13), the deswirl completion status of the buffer (2), the opening status of the settling oil outlet pipe (32), and the opening status of the settling water outlet pipe (33). The operation write-back calibration module adjusts the residual oil load coefficient and the operation parameters of the settling oil outlet pipe (32) according to the batch operation records.

8. The multi-stage combined centrifugal and gravity sedimentation oil-water separator for water pollution treatment according to claim 1, characterized in that: The abnormal lockout recovery module receives abnormal information from the device topology binding module, the centrifuge separation status identification module, the buffer despinning completion judgment module, the settling tank interface migration estimation module, and the multi-level on / off window generation module, and controls the centrifuge feed pipe (11), centrifuge oil outlet pipe (12), centrifuge water outlet pipe (13), settling oil outlet pipe (32), and settling water outlet pipe (33) to perform lockout operations according to the abnormal information.

9. The multi-stage combined centrifugal and gravity sedimentation oil-water separator for water pollution treatment according to claim 1, characterized in that: The built-in system of the control component (4) restricts the operation of the control logic and the fixed connection relationship between the centrifuge (1), buffer (2) and settling tank (3) through the device topology binding module. The control process of the multi-level on / off window generation module is executed only when the state chain of the centrifuge outlet pipe (13) passing through the buffer (2) and entering the settling tank (3) is established.

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