Cleaning waste liquid recycling process and system based on multi-level multi-process combination

Abstract

This invention relates to the field of industrial wastewater treatment technology, specifically to a multi-stage, multi-process integrated process and system for reusing cleaning wastewater. The system includes a raw material treatment unit, a buffer purification unit, an ultrafiltration unit, a plate and frame filtration unit, a reverse osmosis unit, and a wastewater collection unit. By incorporating the buffer purification unit, a buffer tank is used to temporarily store the pre-treated liquid from the raw material treatment unit, effectively buffering the impact of fluctuations in parameters such as influent flow rate, concentration, and pH value on subsequent treatment units. Simultaneously, a circulating purification device circulates and purifies the liquid in the buffer tank, achieving homogeneous and stable water quality. Multi-point level sensors are interlocked with the pumps and valves of each unit for automatic start-up and shutdown based on real-time liquid levels, avoiding frequent start-ups and shutdowns and manual intervention due to unstable influent. This solves the problems of unstable continuous operation, low treatment efficiency, and unstable effluent quality caused by instability in influent in existing technologies.

Description

Technical Field

[0001] This invention relates to the field of industrial wastewater treatment technology, and in particular to a process and system for reusing cleaning wastewater based on a multi-level and multi-process combination. Background Technology

[0002] Industrial cleaning processes generate large quantities of cleaning wastewater containing oil, organic matter, suspended solids, and chemical additives. Direct discharge of this wastewater not only wastes water resources but also causes serious environmental pollution. Therefore, the reuse and treatment of cleaning wastewater is of great significance.

[0003] Currently, commonly used methods for treating cleaning wastewater in existing technologies include physical methods (such as gravity sedimentation, flotation, reverse osmosis, ultrafiltration, etc.), chemical methods (such as neutralization, oxidation-reduction, coagulation sedimentation, etc.), biological methods (such as activated sludge process, biofilm process, etc.), membrane separation technology (such as ultrafiltration + reverse osmosis dual membrane process, MBR membrane bioreactor), evaporation concentration and low temperature evaporation technology, as well as fractional reuse and series utilization methods.

[0004] However, the above-mentioned existing technologies have the following drawbacks in practical applications: due to the instability of the incoming liquid (such as large fluctuations in parameters such as water quality, water quantity, pH value, conductivity, and viscosity), the treatment equipment cannot achieve stable and continuous operation, resulting in low treatment efficiency, unstable effluent quality, and difficulty in meeting the requirements for reuse. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-level, multi-process combined cleaning wastewater reuse process and system, which solves the problems in the prior art where the equipment cannot operate stably and continuously due to the instability of the incoming liquid, resulting in low treatment efficiency, unstable effluent quality, and difficulty in meeting reuse requirements.

[0006] To achieve the above objectives, the present invention provides a multi-level, multi-process integrated cleaning wastewater reuse system. The multi-level, multi-process integrated cleaning wastewater reuse system includes a raw liquid treatment unit, a buffer purification unit, an ultrafiltration unit, a plate and frame filtration unit, a reverse osmosis unit, and a wastewater collection unit. The input end of the raw liquid treatment unit is connected to the output end of the cleaning tank. The raw liquid treatment unit is used to perform pH adjustment and oil separation pretreatment on the cleaning wastewater discharged from the cleaning tank. The buffer purification unit includes a buffer tank and a circulating purification device. The input end of the circulating purification device is connected to the output end of the original liquid treatment unit. The circulating purification device is connected to the buffer tank at both ends. The circulating purification device is used to transport the pre-treated liquid from the original liquid treatment unit to the buffer tank and to circulate and purify the liquid in the buffer tank. The input end of the ultrafiltration unit is connected to the output end of the buffer tank, and the ultrafiltration unit is used to perform ultrafiltration treatment on the buffer purified liquid. The input end of the plate and frame filter unit is connected to the output end of the ultrafiltration unit, and the plate and frame filter unit is used to perform plate and frame filtration on the liquid after ultrafiltration. The input end of the reverse osmosis unit is connected to the output end of the plate and frame filter unit. The reverse osmosis unit is used to perform reverse osmosis treatment on the liquid after plate and frame filtration to obtain recycled purified liquid, and to transport the waste liquid generated during the reverse osmosis treatment to the waste liquid collection unit. The waste liquid collection unit is used to collect the waste liquid separated by the reverse osmosis unit. The raw material treatment unit, the buffer purification unit, the ultrafiltration unit, the plate and frame filtration unit, and the reverse osmosis unit are all equipped with multi-point liquid level sensors. The multiple multi-point liquid level sensors are connected to the pumps and valves of each unit and are used to control the start and stop of the pumps and valves of each unit according to the detected liquid level.

[0007] The raw liquid treatment unit includes a raw water inlet pump, a raw liquid tank, an oil separator, a waste oil tank, a raw water pH detection pump, an acid addition pump, and a first filtration transfer pump. The inlet of the raw water inlet pump is connected to the cleaning water tank, and the outlet of the raw water inlet pump is connected to the inlet of the raw liquid tank. The oil separator is installed at the raw liquid tank, and the oil outlet of the oil separator is connected to the waste oil tank. The inlet of the raw water pH detection pump is connected to the raw liquid tank pipeline. The acid addition pump is linked and controlled with the raw water pH detection pump. The first filtration transfer pump is connected between the outlet of the raw liquid tank and the waste oil tank. A first drain valve is installed on the pipeline connecting the first filtration transfer pump and the outlet of the raw liquid tank. The first drain valve is connected to the input of the waste liquid collection unit. The waste oil tank is connected to the circulation purification equipment pipeline. A first multi-point liquid level sensor is installed inside the raw liquid tank.

[0008] The buffer purification unit further includes a buffer transfer pump, the inlet of which is connected to the buffer tank, and the outlet of which is connected to the input of the ultrafiltration unit. A second multi-point liquid level sensor is installed inside the buffer tank.

[0009] The ultrafiltration unit includes a first filter, a water storage tank, a first ultrafiltration device, a second ultrafiltration device, a negative pressure self-cleaning ultrafiltration device, an ultrafiltration discharge pump, a first control valve, a second control valve, a third control valve, a first bottom valve, a second bottom valve, and a second discharge valve. The input end of the first filter is connected to the output end of the buffer purification unit, and the output end of the first filter is connected to the input end of the water storage tank. The output end of the water storage tank is connected to the input ends of the first ultrafiltration device, the second ultrafiltration device, and the negative pressure self-cleaning ultrafiltration device, respectively. The output end of the first ultrafiltration device is connected to the input end of the plate and frame filter unit through the first control valve. The output end of the second ultrafiltration device... The output end is connected to the input end of the plate and frame filter unit through the second control valve. The output end of the negative pressure self-cleaning ultrafiltration device is connected to the input end of the plate and frame filter unit through the third control valve. The first bottom valve is set on the bottom drain pipe of the first ultrafiltration device, and the second bottom valve is set on the bottom drain pipe of the second ultrafiltration device. The ultrafiltration drain pump is connected between the bottom of the water storage tank and the input end of the negative pressure self-cleaning ultrafiltration device. The second drain valve is set on the main drain pipe of the first ultrafiltration device, the second ultrafiltration device and the negative pressure self-cleaning ultrafiltration device and is connected to the waste liquid collection unit. A third multi-point liquid level sensor is installed in the water storage tank.

[0010] The plate and frame filtration unit includes a purified liquid tank, a plate and frame filter, and a plate and frame transfer pump. The input end of the purified liquid tank is connected to the output end of the ultrafiltration unit. The plate and frame filter is installed inside the purified liquid tank. The plate and frame transfer pump is connected between the output end of the plate and frame filter and the input end of the reverse osmosis unit. A fourth multi-point liquid level sensor is installed inside the purified liquid tank.

[0011] The reverse osmosis unit includes a first RO tank, a second RO tank, a third RO tank, a purified liquid tank, a first antifouling reverse osmosis device, a second antifouling reverse osmosis device, a desalination ultrafiltration device, a first reflux pump, a second reflux pump, an emptying pump, and a purified liquid output pump. The input end of the first RO tank is connected to the output end of the plate and frame filter unit. The output end of the first RO tank is connected to the input end of the first antifouling reverse osmosis device. The output end of the first antifouling reverse osmosis device is connected to the input end of the second RO tank. The output end of the second RO tank is connected to the input end of the second antifouling reverse osmosis device. The output end of the second antifouling reverse osmosis device is connected to the input end of the purified liquid tank. The output end of the third RO tank is connected to... The input end of the desalination ultrafiltration device is connected, the output end of the desalination ultrafiltration device is connected to the input end of the first RO tank, the first reflux pump is connected between the bottom of the second RO tank and the input end of the first RO tank, the second reflux pump is connected between the bottom of the first RO tank and the input end of the third RO tank, the venting pump is connected between the bottom of the third RO tank and the waste liquid collection unit, the purified liquid output pump is connected to the bottom of the purified liquid tank, a fifth multi-point liquid level sensor is installed in the first RO tank, a sixth multi-point liquid level sensor is installed in the second RO tank, a seventh multi-point liquid level sensor is installed in the third RO tank, and an eighth multi-point liquid level sensor is installed in the purified liquid tank.

[0012] The reverse osmosis unit further includes a third transfer pump, which is connected between the output end of the first antifouling reverse osmosis device and the input end of the second RO tank.

[0013] The waste liquid collection unit includes a waste liquid tank, and a ninth multi-point liquid level sensor is installed inside the waste liquid tank.

[0014] This invention also provides a cleaning wastewater reuse process based on a multi-level, multi-process combination, applied to the cleaning wastewater reuse system based on a multi-level, multi-process combination as described above, comprising the following steps: The original solution treatment unit performs pH adjustment and oil separation pretreatment on the cleaning waste liquid discharged from the cleaning tank. The pretreated liquid from the raw liquid treatment unit is transported to the buffer tank through the circulating purification device, and the liquid in the buffer tank is circulated and purified through the circulating purification device. The ultrafiltration unit is used to ultrafilter the purified liquid after buffering. The ultrafiltration-treated liquid is filtered through the plate and frame filter unit. The liquid filtered by the plate and frame filter is subjected to reverse osmosis treatment through the reverse osmosis unit to obtain recycled purified liquid, and the waste liquid generated during the reverse osmosis treatment process is transported to the waste liquid collection unit.

[0015] This invention discloses a multi-level, multi-process integrated cleaning wastewater reuse process and system, comprising a raw liquid treatment unit, a buffer purification unit, an ultrafiltration unit, a plate and frame filtration unit, a reverse osmosis unit, and a wastewater collection unit. By incorporating the buffer purification unit, the pre-treated liquid from the raw liquid treatment unit is temporarily stored in a buffer tank, effectively buffering the impact of fluctuations in parameters such as influent flow rate, concentration, and pH value on subsequent treatment units. Simultaneously, the circulating purification equipment circulates and purifies the liquid in the buffer tank, achieving homogeneous and stable water quality. Furthermore, multi-point liquid level sensors are interlocked with the pumps and valves of each unit for automatic start-up and shutdown based on real-time liquid levels, avoiding frequent start-ups and shutdowns and manual intervention due to unstable influent. This structure solves the problems of unstable continuous operation, low treatment efficiency, and unstable effluent quality caused by instability in influent in existing technologies, ensuring stable system operation and meeting reuse requirements. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the cleaning waste liquid reuse system based on the combination of multiple levels and multiple processes provided by the present invention.

[0018] Figure 2 This is a schematic diagram of the connection structure between the original liquid treatment unit and the buffer purification unit provided by the present invention.

[0019] Figure 3 This is a schematic diagram of the structure of the ultrafiltration unit provided by the present invention.

[0020] Figure 4 This is a schematic diagram of the plate and frame filter unit provided by the present invention.

[0021] Figure 5 This is a schematic diagram of the connection structure between the reverse osmosis unit and the waste liquid collection unit provided by the present invention.

[0022] Figure 6 This is a flowchart of the cleaning waste liquid reuse process based on multi-level and multi-process combination provided by the present invention.

[0023] 101-Cleaning water tank, 102-Buffer tank, 103-Circulating purification equipment, 104-Raw water inlet pump, 105-Raw liquid tank, 106-Oil separator, 107-Waste oil tank, 108-Raw water pH detection pump, 109-Acid pump, 110-First filter transfer pump, 111-First drain valve, 112-First multi-point level sensor, 113-Buffer transfer pump, 114-Second multi-point level sensor, 115-First filter, 116-Water storage tank, 117-First ultrafiltration device, 118-Second ultrafiltration device, 119-Negative pressure self-cleaning ultrafiltration device, 120-Ultrafiltration drain pump, 121-First control valve, 122-Second control valve, 123-Third control valve, 124-First bottom valve, 125-Second bottom valve, 126-Second drain valve Liquid valve, 127-Third multi-point liquid level sensor, 128-Clean liquid tank, 129-Plate and frame filter, 130-Plate and frame transfer pump, 131-Fourth multi-point liquid level sensor, 132-First RO tank, 133-Second RO tank, 134-Third RO tank, 135-Clean liquid tank, 136-First anti-fouling reverse osmosis device, 137-Second anti-fouling reverse osmosis device, 138-Seawater desalination ultrafiltration device, 139-First reflux pump, 140-Second reflux pump, 141-Drain pump, 142-Clean liquid output pump, 143-Fifth multi-point liquid level sensor, 144-Sixth multi-point liquid level sensor, 145-Seventh multi-point liquid level sensor, 146-Eighth multi-point liquid level sensor, 147-Third transfer pump, 148-Waste liquid tank, 149-Ninth multi-point liquid level sensor. Detailed Implementation

[0024] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0025] Please see Figures 1 to 5 This invention provides a multi-level, multi-process integrated cleaning wastewater reuse system. The multi-level, multi-process integrated cleaning wastewater reuse system includes a raw liquid treatment unit, a buffer purification unit, an ultrafiltration unit, a plate and frame filtration unit, a reverse osmosis unit, and a wastewater collection unit. The input end of the raw liquid treatment unit is connected to the output end of the cleaning tank 101. The raw liquid treatment unit is used to perform pH adjustment and oil separation pretreatment on the cleaning wastewater discharged from the cleaning tank 101. The buffer purification unit includes a buffer tank 102 and a circulating purification device 103. The input end of the circulating purification device 103 is connected to the output end of the original liquid treatment unit. The circulating purification device 103 is connected to the buffer tank 102 at both ends. The circulating purification device 103 is used to transport the pre-treated liquid from the original liquid treatment unit to the buffer tank 102 and to circulate and purify the liquid in the buffer tank 102. The input end of the ultrafiltration unit is connected to the output end of the buffer tank 102, and the ultrafiltration unit is used to perform ultrafiltration treatment on the buffered and purified liquid. The input end of the plate and frame filter unit is connected to the output end of the ultrafiltration unit, and the plate and frame filter unit is used to perform plate and frame filtration on the liquid after ultrafiltration. The input end of the reverse osmosis unit is connected to the output end of the plate and frame filter unit. The reverse osmosis unit is used to perform reverse osmosis treatment on the liquid after plate and frame filtration to obtain recycled purified liquid, and to transport the waste liquid generated during the reverse osmosis treatment to the waste liquid collection unit. The waste liquid collection unit is used to collect the waste liquid separated by the reverse osmosis unit. The raw material treatment unit, the buffer purification unit, the ultrafiltration unit, the plate and frame filtration unit, and the reverse osmosis unit are all equipped with multi-point liquid level sensors. The multiple multi-point liquid level sensors are connected to the pumps and valves of each unit and are used to control the start and stop of the pumps and valves of each unit according to the detected liquid level.

[0026] In this embodiment, by setting up the buffer purification unit, the buffer tank 102 is used to temporarily store the liquid pretreated by the raw liquid treatment unit, effectively buffering the impact of fluctuations in parameters such as incoming liquid flow rate, concentration, and pH value on subsequent treatment units. Simultaneously, the circulating purification device 103 circulates and purifies the liquid in the buffer tank 102, achieving homogeneous and stable water quality. Furthermore, the multi-point liquid level sensor is interlocked with the pumps and valves of each unit for automatic start-up and shutdown based on the real-time liquid level, avoiding frequent start-ups and shutdowns and manual intervention due to unstable incoming liquid. Through this structure, the problems of unstable continuous operation, low treatment efficiency, and unstable effluent quality caused by unstable incoming liquid in the prior art are solved, ensuring stable system operation and meeting reuse requirements.

[0027] Furthermore, the raw liquid treatment unit includes a raw water inlet pump 104, a raw liquid tank 105, an oil separator 106, a waste oil tank 107, a raw water pH detection pump 108, an acid addition pump 109, and a first filtration transfer pump 110. The inlet of the raw water inlet pump 104 is connected to the cleaning water tank 101, and the outlet of the raw water inlet pump 104 is connected to the inlet of the raw liquid tank 105. The oil separator 106 is installed at the raw liquid tank 105, and the oil outlet of the oil separator 106 is connected to the waste oil tank 107. The inlet of the raw water pH detection pump 108 is connected to the... The raw liquid tank 105 is connected by a pipeline. The acid pump 109 is linked and controlled with the raw water pH detection pump 108. The first filter transfer pump 110 is connected between the outlet end of the raw liquid tank 105 and the waste oil tank 107. A first drain valve 111 is installed on the pipeline connecting the first filter transfer pump 110 and the outlet end of the raw liquid tank 105. The first drain valve 111 is connected to the input end of the waste liquid collection unit. The waste oil tank 107 is connected by a pipeline to the circulating purification equipment 103. A first multi-point liquid level sensor 112 is installed inside the raw liquid tank 105.

[0028] In this embodiment, the raw water inlet pump 104 is used to pump the cleaning waste liquid in the cleaning tank 101 into the raw liquid tank 105. The oil separator 106 is used to circulate the liquid in the raw liquid tank 105 to separate floating oil by taking liquid from the liquid surface. The separated floating oil is transported to the waste oil tank 107. The raw water pH detection pump 108 is used to circulate and detect the pH value of the liquid in the raw liquid tank 105. The acid addition pump 109 is used to add acid to the raw liquid tank 105 when the pH value is greater than a set value until the pH value reaches the standard. The first filter transfer pump 110 is used to transport the liquid in the raw liquid tank 105 to the waste oil tank 107. The first drain valve 111 is used to transport the waste liquid in the raw liquid tank 105 to the waste liquid collection unit when the waste liquid in the raw liquid tank 105 needs to be discharged. The liquid in the waste oil tank 107 is transported to the circulating purification equipment 103 through the pipeline and then enters the buffer tank 102. The first multi-point liquid level sensor 112 includes liquid level points ls101-1, ls101-2, ls101-3 and ls101-4.

[0029] Furthermore, the buffer purification unit also includes a buffer transfer pump 113, the inlet of which is connected to the buffer tank 102, and the outlet of which is connected to the input of the ultrafiltration unit. A second multi-point liquid level sensor 114 is provided inside the buffer tank 102.

[0030] In this embodiment, the buffer transfer pump 113 is used to transport the purified liquid circulating in the buffer tank 102 to the ultrafiltration unit, and the second multi-point liquid level sensor 114 includes liquid level points ls102-1, ls102-2, ls102-3 and ls102-4.

[0031] Furthermore, the ultrafiltration unit includes a first filter 115, a water storage tank 116, a first ultrafiltration device 117, a second ultrafiltration device 118, a negative pressure self-cleaning ultrafiltration device 119, an ultrafiltration drainage pump 120, a first control valve 121, a second control valve 122, a third control valve 123, a first bottom valve 124, a second bottom valve 125, and a second drainage valve 126. The input end of the first filter 115 is connected to the output end of the buffer purification unit, and the output end of the first filter 115 is connected to the input end of the water storage tank 116. The output end of the water storage tank 116 is connected to the input ends of the first ultrafiltration device 117, the second ultrafiltration device 118, and the negative pressure self-cleaning ultrafiltration device 119, respectively. The output end of the first ultrafiltration device 117 is connected to the input end of the plate and frame filter unit through the first control valve 121. The output end of the second ultrafiltration device 118 is connected to the input end of the plate and frame filter unit through the second control valve 122. The output end of the negative pressure self-cleaning ultrafiltration device 119 is connected to the input end of the plate and frame filter unit through the third control valve 123. The first bottom valve 124 is located on the bottom drain pipe of the first ultrafiltration device 117. The second bottom valve 125 is located on the bottom drain pipe of the second ultrafiltration device 118. The ultrafiltration drain pump 120 is connected between the bottom of the water storage tank 116 and the input end of the negative pressure self-cleaning ultrafiltration device 119. The second drain valve 126 is located on the main drain pipe of the first ultrafiltration device 117, the second ultrafiltration device 118 and the negative pressure self-cleaning ultrafiltration device 119 and is connected to the waste liquid collection unit. A third multi-point liquid level sensor 127 is installed in the water storage tank 116.

[0032] In this embodiment, the first filter 115 is used to filter the liquid output from the buffer purification unit, the water storage tank 116 is used to temporarily store the filtered liquid, the first ultrafiltration device 117, the second ultrafiltration device 118, and the negative pressure self-cleaning ultrafiltration device 119 are used to perform ultrafiltration treatment on the liquid, the first control valve 121 is used to control the purified liquid output of the first ultrafiltration device 117, the second control valve 122 is used to control the purified liquid output of the second ultrafiltration device 118, and the third control valve 123 is used to control the negative pressure self-cleaning ultrafiltration device. The purified liquid output of 119, the first bottom valve 124 is used to control the bottom discharge of the first ultrafiltration device 117, the second bottom valve 125 is used to control the bottom discharge of the second ultrafiltration device 118, the ultrafiltration discharge pump 120 is used to transport the liquid at the bottom of the water storage tank 116 to the negative pressure self-cleaning ultrafiltration device 119, the second discharge valve 126 is used to transport the waste liquid generated by backwashing to the waste liquid collection unit, and the third multi-point liquid level sensor 127 includes liquid level points ls103-1, ls103-2, ls103-3 and ls103-4.

[0033] Furthermore, the plate and frame filtration unit includes a purified liquid tank 128, a plate and frame filter 129, and a plate and frame transfer pump 130. The input end of the purified liquid tank 128 is connected to the output end of the ultrafiltration unit. The plate and frame filter 129 is disposed inside the purified liquid tank 128. The plate and frame transfer pump 130 is connected between the output end of the plate and frame filter 129 and the input end of the reverse osmosis unit. A fourth multi-point liquid level sensor 131 is disposed inside the purified liquid tank 128.

[0034] In this embodiment, the purified liquid tank 128 is used to temporarily store the purified liquid after treatment by the ultrafiltration unit, the plate and frame filter 129 is used to perform plate and frame filtration on the purified liquid, the plate and frame transfer pump 130 is used to transport the liquid after plate and frame filtration to the reverse osmosis unit, and the fourth multi-point liquid level sensor 131 includes liquid level points ls211-1, ls211-2 and ls211-3.

[0035] Furthermore, the reverse osmosis unit includes a first RO tank 132, a second RO tank 133, a third RO tank 134, a purified liquid tank 135, a first antifouling reverse osmosis device 136, a second antifouling reverse osmosis device 137, a desalination ultrafiltration device 138, a first reflux pump 139, a second reflux pump 140, an emptying pump 141, and a purified liquid output pump 142. The input end of the first RO tank 132 is connected to the output end of the plate and frame filter unit, the output end of the first RO tank 132 is connected to the input end of the first antifouling reverse osmosis device 136, the output end of the first antifouling reverse osmosis device 136 is connected to the input end of the second RO tank 133, the output end of the second RO tank 133 is connected to the input end of the second antifouling reverse osmosis device 137, the output end of the second antifouling reverse osmosis device 137 is connected to the input end of the purified liquid tank 135, and the output end of the third RO tank 134 is connected to the input end of the purified liquid tank 135. The first RO tank 132 is connected to the input end of the desalination ultrafiltration device 138, the output end of the desalination ultrafiltration device 138 is connected to the input end of the first RO tank 132, the first reflux pump 139 is connected between the bottom of the second RO tank 133 and the input end of the first RO tank 132, the second reflux pump 140 is connected between the bottom of the first RO tank 132 and the input end of the third RO tank 134, the evacuation pump 141 is connected between the bottom of the third RO tank 134 and the waste liquid collection unit, the purified liquid output pump 142 is connected to the bottom of the purified liquid tank 135, the first RO tank 132 is equipped with a fifth multi-point liquid level sensor 143, the second RO tank 133 is equipped with a sixth multi-point liquid level sensor 144, the third RO tank 134 is equipped with a seventh multi-point liquid level sensor 145, and the purified liquid tank 135 is equipped with an eighth multi-point liquid level sensor 146.

[0036] In this embodiment, the first RO tank 132 is used to temporarily store the liquid output from the plate and frame filter unit; the first antifouling reverse osmosis device 136 is used to perform antifouling reverse osmosis treatment on the liquid in the first RO tank 132; the second RO tank 133 is used to temporarily store the liquid treated by the first antifouling reverse osmosis device 136; the second antifouling reverse osmosis device 137 is used to perform secondary antifouling reverse osmosis treatment on the liquid in the second RO tank 133; the purified liquid tank 135 is used to collect the recycled purified liquid output by the second antifouling reverse osmosis device 137; the third RO tank 134 is used to temporarily store liquid to be treated; the desalination ultrafiltration device 138 is used to perform desalination ultrafiltration treatment on the liquid in the third RO tank 134; the first reflux pump 139 is used to return the liquid at the bottom of the second RO tank 133 to the first RO tank 132; and the second reflux pump 1... The pump 40 is used to transport the liquid at the bottom of the first RO tank 132 to the third RO tank 134. The evacuation pump 141 is used to transport the waste liquid at the bottom of the third RO tank 134 to the waste liquid collection unit. The purified liquid output pump 142 is used to output the recycled purified liquid in the purified liquid tank 135. The fifth multi-point liquid level sensor 143 includes liquid level points ls104-1, ls104-2, ls104-3, ls104-4 and ls104-5. The sixth multi-point liquid level sensor 144 includes liquid level points ls111-1 and ls111-2. The seventh multi-point liquid level sensor 145 includes liquid level points ls112-1, ls112-2, ls112-3 and ls112-4. The eighth multi-point liquid level sensor 146 includes liquid level points ls105-1, ls105-2, ls105-3 and ls105-4.

[0037] Furthermore, the reverse osmosis unit also includes a third transfer pump 147, which is connected between the output end of the first antifouling reverse osmosis device 136 and the input end of the second RO tank 133.

[0038] In this embodiment, the third transfer pump 147 is used to transport the liquid output from the first antifouling reverse osmosis device 136 to the second RO tank 133.

[0039] Furthermore, the waste liquid collection unit includes a waste liquid tank 148, and a ninth multi-point liquid level sensor 149 is installed inside the waste liquid tank 148.

[0040] In this embodiment, the waste liquid tank 148 is used to collect the waste liquid separated by the raw liquid treatment unit, the ultrafiltration unit and the reverse osmosis unit, and the ninth multi-point liquid level sensor 149 includes liquid level points ls110-1 and ls110-2.

[0041] Please see Figure 6The present invention also provides a cleaning wastewater reuse process based on a multi-level, multi-process combination, applied to the cleaning wastewater reuse system based on the multi-level, multi-process combination described above, comprising the following steps: S1: The cleaning waste liquid discharged from the cleaning tank 101 is subjected to pH adjustment and oil separation pretreatment through the original liquid treatment unit. S2: The pre-treated liquid from the original liquid treatment unit is transported to the buffer tank 102 by the circulating purification device 103, and the liquid in the buffer tank 102 is circulated and purified by the circulating purification device 103. S3: The ultrafiltration unit is used to perform ultrafiltration treatment on the buffered and purified liquid; S4: The ultrafiltration-treated liquid is filtered by the plate and frame filtration unit; S5: The liquid filtered by the plate and frame filter is subjected to reverse osmosis treatment through the reverse osmosis unit to obtain recycled clean liquid, and the waste liquid generated during the reverse osmosis treatment is transported to the waste liquid collection unit.

[0042] In this embodiment, the method uses the buffer tank 102 to temporarily store the pretreated liquid to buffer fluctuations in parameters such as incoming liquid flow rate, concentration, and pH value. At the same time, the circulating purification device 103 circulates and purifies the liquid in the buffer tank 102 to achieve water quality homogenization. Then, the liquid is treated sequentially by ultrafiltration, plate and frame filtration, and reverse osmosis. This effectively solves the problems of unstable continuous operation of equipment, low treatment efficiency, and unstable effluent quality caused by the instability of incoming liquid in the prior art. It realizes the stable automatic operation of the system and ensures that the water quality of the reused purified water meets the standards.

[0043] The specific application process of the cleaning wastewater reuse process based on multi-level and multi-process integration is as follows: The raw water inlet pump 104 is started to transport the cleaning waste liquid in the cleaning tank 101 to the raw liquid tank 105. When the liquid level in the raw liquid tank 105 reaches the high level protection and ultra-high level protection, an alarm is triggered. After the raw water inlet pump 104 stops, when the liquid level in the raw liquid tank 105 is above LS101-3, the raw water pH detection pump 108 is started for circulation detection. When the pH value is greater than the set value, the acid addition pump 109 is started to add acid until the pH value is less than or equal to the set value, allowing the raw liquid tank 105 to transfer liquid to the buffer tank 102. At the same time, the oil separator 106 is started to circulate the liquid in the raw liquid tank 105 and take liquid from the liquid surface. The separated floating oil is transported to the waste oil tank 107. The liquid in the waste oil tank 107 is transported through a pipeline to the circulating purification equipment 103 and then enters the buffer tank 102. The liquid in the raw liquid tank 105 is transported to the buffer tank 102 through the first filter transfer pump 110. The circulating purification equipment 103 is started to circulate and purify the liquid in the buffer tank 102. When the liquid level in the buffer tank 102 is higher than LS102-4, the buffer transfer pump 113 is allowed to start, and the buffer transfer pump 113 is started when the pressure switch of the first filter 115 does not operate; when the liquid level in the water storage tank 116 is lower than LS103-3, the buffer transfer pump 113 is started, and when the liquid level in the water storage tank 116 reaches LS103-2 or LS103-1, the buffer transfer pump 113 is stopped. The liquid in the water storage tank 116 enters the first ultrafiltration device 117, the second ultrafiltration device 118, and the negative pressure self-cleaning ultrafiltration device 119 for ultrafiltration treatment. The first ultrafiltration device 117 and the second ultrafiltration device 118 adopt a timed backwashing process, which stops after a set time. The first bottom valve 124 or the second bottom valve 125 and the ultrafiltration drainage pump 120 are opened to drain the liquid into the negative pressure self-cleaning ultrafiltration device 119. After emptying, the air inlet valve is opened to allow air to enter, and the liquid is discharged to the waste liquid collection unit through the second drainage valve 126. The negative pressure self-cleaning ultrafiltration device 119 adopts a timed self-cleaning process, which cleans for a set duration at set intervals. The air inlet valve is opened to allow air to enter, and the cylinder moves up and down to clean. The purified liquid after ultrafiltration enters the purified liquid tank 128 and is pumped into the plate and frame filter 129 for plate and frame filtration by the pneumatic diaphragm pump and the plate and frame transfer pump 130. The plate and frame transfer pump 130 is controlled by LS211-2 to enable start and LS211-3 to stop operation. The liquid after plate and frame filtration enters the first RO tank 132. When the liquid level in the first RO tank 132 is higher than LS104-4, the raw water pump of the first antifouling reverse osmosis device 136 is started, and it stops when it is lower than LS104-5. When the liquid level in the first RO tank 132 is higher than LS104-3, the high-pressure pump of the first antifouling reverse osmosis device 136 is started, and it stops when it is lower than LS104-4. The purified liquid from the first antifouling reverse osmosis device 136 is discharged to the second RO tank 133. The liquid in the second RO tank 133 enters the second antifouling reverse osmosis device 137 for treatment. The device starts when the liquid level in the second RO tank 133 is higher than LS111-1 and stops when it is lower than LS111-2. When the conductivity is higher than the set value DD02, the purified liquid is discharged to the first RO tank 132. When the conductivity is lower than DD02-50, the purified liquid is discharged to the purified liquid tank 135. The liquid in the third RO tank 134 enters the desalination ultrafiltration device 138 for processing. The device starts when the liquid level in the third RO tank 134 is above LS112-3 and stops when it is below LS112-4, with the purified liquid discharged to the first RO tank 132. Each time the desalination ultrafiltration device 138 stops due to the liquid level being below LS112-4, the drain pump 141 is started to transfer the liquid to the waste liquid tank 148. The drain pump 141 is turned off after a set delay when the liquid level is below LS112-4. When the desalination ultrafiltration device 138 has run for a set time and the conductivity value of the first RO tank 132 is greater than or equal to DD01-500, the drain pump 141 is forcibly started to drain the liquid to the waste liquid tank 148. When the liquid level in the purified liquid tank 135 is higher than LS105-3, the purified liquid output pump 142 is activated to output the purified liquid for reuse; when the liquid level is lower than LS105-4, the pump stops.

[0044] The above description discloses only one preferred embodiment of the present invention, and should not be construed as limiting the scope of the present invention. Those skilled in the art will understand that all or part of the processes of the above embodiments can be implemented, and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A cleaning wastewater reuse system based on a multi-level, multi-process combination, characterized in that, It includes a raw liquid treatment unit, a buffer purification unit, an ultrafiltration unit, a plate and frame filtration unit, a reverse osmosis unit, and a waste liquid collection unit. The input end of the raw liquid treatment unit is connected to the output end of the cleaning water tank. The raw liquid treatment unit is used to perform pH adjustment and oil separation pretreatment on the cleaning waste liquid discharged from the cleaning water tank. The buffer purification unit includes a buffer tank and a circulating purification device. The input end of the circulating purification device is connected to the output end of the original liquid treatment unit. The circulating purification device is connected to the buffer tank at both ends. The circulating purification device is used to transport the pre-treated liquid from the original liquid treatment unit to the buffer tank and to circulate and purify the liquid in the buffer tank. The input end of the ultrafiltration unit is connected to the output end of the buffer tank, and the ultrafiltration unit is used to perform ultrafiltration treatment on the buffer purified liquid. The input end of the plate and frame filter unit is connected to the output end of the ultrafiltration unit, and the plate and frame filter unit is used to perform plate and frame filtration on the liquid after ultrafiltration. The input end of the reverse osmosis unit is connected to the output end of the plate and frame filter unit. The reverse osmosis unit is used to perform reverse osmosis treatment on the liquid after plate and frame filtration to obtain recycled purified liquid, and to transport the waste liquid generated during the reverse osmosis treatment to the waste liquid collection unit. The waste liquid collection unit is used to collect the waste liquid separated by the reverse osmosis unit. The raw material treatment unit, the buffer purification unit, the ultrafiltration unit, the plate and frame filtration unit, and the reverse osmosis unit are all equipped with multi-point liquid level sensors. The multiple multi-point liquid level sensors are connected to the pumps and valves of each unit and are used to control the start and stop of the pumps and valves of each unit according to the detected liquid level.

2. The cleaning wastewater reuse system based on multi-level and multi-process integration as described in claim 1, characterized in that, The raw liquid treatment unit includes a raw water inlet pump, a raw liquid tank, an oil separator, a waste oil tank, a raw water pH detection pump, an acid addition pump, and a first filtration transfer pump. The inlet of the raw water inlet pump is connected to the cleaning water tank, and the outlet of the raw water inlet pump is connected to the inlet of the raw liquid tank. The oil separator is installed at the raw liquid tank, and the oil outlet of the oil separator is connected to the waste oil tank. The inlet of the raw water pH detection pump is connected to the raw liquid tank pipeline. The acid addition pump is linked and controlled with the raw water pH detection pump. The first filtration transfer pump is connected between the outlet of the raw liquid tank and the waste oil tank. A first drain valve is installed on the pipeline connecting the first filtration transfer pump and the outlet of the raw liquid tank. The first drain valve is connected to the input of the waste liquid collection unit. The waste oil tank is connected to the circulation purification equipment pipeline. A first multi-point liquid level sensor is installed inside the raw liquid tank.

3. The cleaning wastewater reuse system based on multi-level and multi-process integration as described in claim 2, characterized in that, The buffer purification unit also includes a buffer transfer pump, the inlet of which is connected to the buffer tank, and the outlet of which is connected to the input of the ultrafiltration unit. A second multi-point liquid level sensor is installed inside the buffer tank.

4. The cleaning wastewater reuse system based on multi-level and multi-process integration as described in claim 3, characterized in that, The ultrafiltration unit includes a first filter, a water storage tank, a first ultrafiltration device, a second ultrafiltration device, a negative pressure self-cleaning ultrafiltration device, an ultrafiltration drainage pump, a first control valve, a second control valve, a third control valve, a first bottom valve, a second bottom valve, and a second drainage valve. The input end of the first filter is connected to the output end of the buffer purification unit, and the output end of the first filter is connected to the input end of the water storage tank. The output end of the water storage tank is connected to the input ends of the first ultrafiltration device, the second ultrafiltration device, and the negative pressure self-cleaning ultrafiltration device, respectively. The output end of the first ultrafiltration device is connected to the input end of the plate and frame filter unit through the first control valve, and the output end of the second ultrafiltration device... The second control valve is connected to the input end of the plate and frame filter unit. The output end of the negative pressure self-cleaning ultrafiltration device is connected to the input end of the plate and frame filter unit through the third control valve. The first bottom valve is set on the bottom drain pipe of the first ultrafiltration device, and the second bottom valve is set on the bottom drain pipe of the second ultrafiltration device. The ultrafiltration drain pump is connected between the bottom of the water storage tank and the input end of the negative pressure self-cleaning ultrafiltration device. The second drain valve is set on the main drain pipe of the first ultrafiltration device, the second ultrafiltration device and the negative pressure self-cleaning ultrafiltration device and is connected to the waste liquid collection unit. A third multi-point liquid level sensor is set in the water storage tank.

5. The cleaning wastewater reuse system based on multi-level and multi-process integration as described in claim 4, characterized in that, The plate and frame filtration unit includes a purified liquid tank, a plate and frame filter, and a plate and frame transfer pump. The input end of the purified liquid tank is connected to the output end of the ultrafiltration unit. The plate and frame filter is installed inside the purified liquid tank. The plate and frame transfer pump is connected between the output end of the plate and frame filter and the input end of the reverse osmosis unit. A fourth multi-point liquid level sensor is installed inside the purified liquid tank.

6. The cleaning wastewater reuse system based on multi-level and multi-process integration as described in claim 5, characterized in that, The reverse osmosis unit includes a first RO tank, a second RO tank, a third RO tank, a purified liquid tank, a first antifouling reverse osmosis device, a second antifouling reverse osmosis device, a desalination ultrafiltration device, a first reflux pump, a second reflux pump, an emptying pump, and a purified liquid output pump. The input end of the first RO tank is connected to the output end of the plate and frame filter unit. The output end of the first RO tank is connected to the input end of the first antifouling reverse osmosis device. The output end of the first antifouling reverse osmosis device is connected to the input end of the second RO tank. The output end of the second antifouling reverse osmosis device is connected to the input end of the purified liquid tank. The output end of the third RO tank is connected to the... The input end of the desalination ultrafiltration device is connected, and the output end of the desalination ultrafiltration device is connected to the input end of the first RO tank. The first reflux pump is connected between the bottom of the second RO tank and the input end of the first RO tank. The second reflux pump is connected between the bottom of the first RO tank and the input end of the third RO tank. The venting pump is connected between the bottom of the third RO tank and the waste liquid collection unit. The purified liquid output pump is connected to the bottom of the purified liquid tank. A fifth multi-point liquid level sensor is installed in the first RO tank, a sixth multi-point liquid level sensor is installed in the second RO tank, a seventh multi-point liquid level sensor is installed in the third RO tank, and an eighth multi-point liquid level sensor is installed in the purified liquid tank.

7. The cleaning wastewater reuse system based on multi-level and multi-process integration as described in claim 6, characterized in that, The reverse osmosis unit also includes a third transfer pump, which is connected between the output end of the first antifouling reverse osmosis device and the input end of the second RO tank.

8. The cleaning wastewater reuse system based on multi-level and multi-process integration as described in claim 7, characterized in that, The waste liquid collection unit includes a waste liquid tank, and a ninth multi-point liquid level sensor is installed inside the waste liquid tank.

9. A multi-level multi-process combined cleaning waste liquid recycling process applied to the multi-level multi-process combined cleaning waste liquid recycling system of claim 1, characterized in that, Includes the following steps: The original solution treatment unit performs pH adjustment and oil separation pretreatment on the cleaning waste liquid discharged from the cleaning tank. The pretreated liquid from the raw liquid treatment unit is transported to the buffer tank through the circulating purification device, and the liquid in the buffer tank is circulated and purified through the circulating purification device. The ultrafiltration unit is used to ultrafilter the purified liquid after buffering. The ultrafiltration-treated liquid is filtered through the plate and frame filter unit. The liquid filtered by the plate and frame filter is subjected to reverse osmosis treatment through the reverse osmosis unit to obtain recycled purified liquid, and the waste liquid generated during the reverse osmosis treatment process is transported to the waste liquid collection unit.

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