CN217746604U - System for be used for retrieving abrasive slurry waste liquid - Google Patents

Abstract

This creation embodiment provides a system for retrieving abrasive slurry waste liquid, the system includes stirred tank and filter. The system further comprises: the first pipeline is used for conveying the initial grinding slurry waste liquid to a first inlet of the stirring tank; the second pipeline is used for conveying the waste slurry from the stirring tank to the filter; a third line for conveying concentrated slurry effluent from the filter to the second inlet of the stirred tank; the first valve is used for opening and closing the first pipeline; the hydrometer is used for sensing the solid content of the grinding slurry waste liquid; and a controller configured to control the first valve.

Description

System for be used for retrieving abrasive slurry waste liquid

Technical Field

The present application relates to a recycling method and system, and more particularly, to a recycling system for waste slurry.

Background

The panel is an essential element of the screens of various electronic products. With the evolution of manufacturing technology and the market demand of continuously shrinking volume, the demand of thinning panels is also increasing. For example, in a manufacturing process of a Liquid Crystal Display (LCD) panel, after liquid crystal injection is completed, before the panel is not cut, a substrate of the panel needs to be ground, polished and thinned, so as to facilitate thickness thinning of a panel module.

Currently, a panel substrate is thinned by mixing polishing powder with clear water to prepare a polishing slurry, and then a glass or sapphire substrate is polished by a polishing apparatus and a polishing pad to remove excess thickness and eliminate defect patterns on the substrate. After the polishing or grinding process is completed, the thinned substrate needs to be rinsed with clean water to facilitate removal of the substrate from the polishing pad. Meanwhile, the rinsing water is directly discharged and discarded together with the slurry.

However, with the increasing awareness of environmental protection and the cost of the grinding process, the polishing powder used in the above-mentioned thinning process involving grinding or polishing is not recycled, so the production cost and environmental cost of the thinning process are high. Secondly, the effect of the polishing powder used once is not fully utilized, thereby causing waste of resources. However, a simple and effective polishing powder recycling device is not available, so that most of the polishing powder or slurry cannot be recycled. In view of the above problems, there is a need to develop a recycling method of slurry to increase the recycling life of the polishing powder or slurry and improve the environmental friendliness of the thinning process.

SUMMERY OF THE UTILITY MODEL

An embodiment of this creation provides a system for retrieving abrasive slurry waste liquid, includes: the stirring tank is used for receiving the initial slurry waste liquid and stirring the slurry waste liquid in the stirring tank; a filter for inputting the slurry waste liquid and outputting filtered water and concentrated slurry waste liquid; a pipe (111) connected to the agitator (106) and adapted to convey the initial slurry waste to the first inlet (112) of the agitation tank; a second pipe (113) connecting the stirring tank and the filter (108) and used for conveying the slurry waste liquid from the stirring tank to the filter; a third pipeline (115) connecting the agitation tank and the filter, and for transporting the concentrated slurry waste from the filter to a second inlet of the agitation tank; a first valve (112) for opening and closing the first line; a densitometer (124) arranged on the stirring tank and used for sensing the solid content of the slurry waste liquid; and a controller (140) electrically connected to the first valve and configured to control the first valve.

In one embodiment, the system further comprises: a fourth line (131) for delivering a supplementary polishing powder to the agitation tank; and a second valve (132) for opening and closing the fourth line.

In one embodiment, the system further includes a water level gauge (128) for sensing a level of the slurry waste in the stirred tank.

In one embodiment, the system further includes a booster pump (122) in the path of the first conduit.

In one embodiment, the system further comprises a fifth line (117) connected to the filtered water outlet of the filter and adapted to perform a backwashing procedure on the filter.

In one embodiment, the system further comprises a sixth pipeline (115) connecting the agitation tank and the filter and configured to perform a bubble removal process.

In one embodiment, the controller is configured to determine a first cycle length of the system in the filtering mode and a second cycle length of the system in the concentrating mode.

In one embodiment, the controller is configured to open the first valve (112) to enter the filtration mode and maintain the level of the slurry waste liquid within a predetermined range during the first period.

In one embodiment, in the filtration mode, the slurry effluent has a solids content not greater than the first solids content value.

In one embodiment, at the end of the concentration mode, the slurry waste has a solid content greater than the first solid content value.

Another embodiment of the present disclosure provides a method for recycling waste slurry, comprising: the filtering mode is performed in a first cycle and the concentrating mode is performed in a second cycle. The filtering mode includes: conveying the initial slurry waste liquid to a stirring tank to obtain slurry waste liquid; delivering the slurry waste stream to a filter for filtering, wherein the filter receives the slurry waste stream and produces Filtered Water (FW) and concentrated slurry waste stream; and delivering the concentrated slurry waste (FS) to the stirred tank. The concentration mode includes: stopping conveying the initial slurry waste liquid path to the stirring tank; and conveying the slurry waste liquid to a filter for filtering.

In one embodiment the ratio of the first period to the second period is between 15 and 30 times.

In one embodiment, the method further comprises determining the time length of the first period or the second period by sensing a solid content of the slurry waste in the agitation tank.

In one embodiment, the slurry waste liquid in the stirred tank has a first solid content value at the end of the first period and a second solid content value at the end of the second period, and a ratio of the second solid content value to the first solid content value is between 5 times and 10 times.

In one embodiment, the method includes that the change amount of the solid content of the slurry waste liquid in the stirring tank has a first average speed in the first period and a second average speed in the second period, and the ratio of the second average speed to the first average speed is between 15 times and 30 times.

In one embodiment, the method further comprises maintaining the slurry waste liquid level in the agitation tank within a predetermined height range in the filtration mode.

In one embodiment, the initial slurry waste liquid has a solid content not higher than an initial solid content set value, and in the filtration mode, the slurry waste liquid in the stirring tank has more than one rising and more than one falling solid content values.

In one embodiment, in the concentration mode, the slurry waste liquid in the stirred tank has a continuously increasing solid content value.

In one embodiment, the method further comprises performing a mixing mode in a third period after the concentration mode is finished, stopping filtering the slurry waste liquid, delivering additional polishing powder to the stirring tank to stir with the slurry waste liquid, and outputting the slurry waste liquid at the end of the third period.

In one embodiment, the slurry waste liquid in the stirring tank has a third solid content value at the end of the third period and a second solid content value at the end of the second period, and the ratio of the third solid content value to the second solid content value is between 1.1 times and 2 times.

Therefore, the present disclosure provides a method and a system for recycling waste liquid of polishing slurry, which properly remove excess water in the waste liquid to make the solid content of the waste liquid of the polishing slurry reach an ideal range of application, and the waste liquid can be used as the recycled polishing slurry, so that the polishing powder therein can continue to prolong the service life, thereby achieving the effects of recycling resources and reducing the cost. In addition, the recovery method and the recovery system provided by the scheme can effectively help the grinding slurry waste liquid to recover the efficiency, shorten the concentration time of the grinding slurry waste liquid, effectively protect a filter in the recovery system, prolong the service life of a filter membrane, and improve the efficiency and the cost advantage of the recovery system.

The foregoing has outlined rather broadly the features and advantages of embodiments of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Other technical features and advantages of the subject matter of the present patent application will be described below. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures or methods for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the disclosure as set forth in the appended claims.

Drawings

The disclosure may be more completely understood in consideration of the following detailed description and the appended claims in connection with the accompanying drawings, in which like reference numerals refer to the same or similar elements.

Fig. 1 is a schematic diagram of a waste recovery system, according to some embodiments.

FIG. 2 is a schematic diagram of a filter, according to some embodiments.

Fig. 3 is a flow diagram of a waste recovery method, according to some embodiments.

Figures 4A-4G are schematic diagrams of the operation of a waste recovery system at various stages, according to some embodiments.

Fig. 5 is a graph depicting the variation of solids content of slurry effluent at various stages of operation, in accordance with certain examples.

Detailed Description

Embodiments of the present authoring are discussed in detail below. However, it should be appreciated that the embodiments provide many applicable authoring concepts that can be implemented in a variety of specific contexts. The specific embodiments discussed are merely illustrative of specific ways to make and use the embodiments, and do not limit the scope of the present disclosure.

Like reference numerals refer to like elements throughout the various views and illustrative embodiments. The following description will focus particularly on the elements that are part of, or cooperate more directly with, the apparatus of the present inventive embodiments. Further, it is to be understood that elements not specifically shown or described may take different forms. Reference in the specification to "some embodiments" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in some embodiments" or "in embodiments" in various places throughout this specification are not necessarily referring to the same embodiments. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

In the drawings, like numerals designate the same or similar elements throughout the several views, and there is shown and described an illustrative embodiment of the present composition. The drawings are not necessarily to scale and in some instances, the drawings have been exaggerated and/or simplified for purposes of illustrating the embodiments. Many possible applications and variations of the present authoring will be apparent to one of ordinary skill in the art based on the following illustrative embodiments of the present authoring.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. For example, terms defined in commonly used dictionaries should be interpreted as having a meaning that is consistent with their meaning in the relevant art and herein, and should not be interpreted in an excessively formal sense (unless explicitly defined herein).

In addition, the following embodiments of the present creation are provided as examples to illustrate the core value of the present creation, but not to limit the scope of the present creation. For purposes of clarity and understanding, the same or similar functions or elements will not be repeated among the various embodiments of the present disclosure. Different elements or technical features of different embodiments may be combined or replaced with each other without conflict with each other to obtain a new embodiment.

Fig. 1 is a schematic diagram of a waste recovery system 100, according to some embodiments. The waste fluid recycling system 100 may be used to recycle slurries used in substrate processing, such as processing of substrates made of glass or sapphire, for example, polishing slurries required in thinning processes. In one embodiment, the main components of the polishing slurry include water and polishing powder, and may further include additives such as dispersants, surfactants, corrosion inhibitors, and oxidizing agents, and the actual components and specific gravity of the additives may be adjusted according to different polishing objects. In the present embodiment, the polishing slurry is used to polish a substrate of a display panel, wherein the substrate of the display panel can be made of glass, sapphire or other suitable materials. The polishing powder in the slurry may be formed of abrasive particles made of cerium (Ce), lanthanum (La) or other rare earth elements (e.g., cerium oxide (CeO 2), lanthanum oxide (La 2O 3)).

In one embodiment, for the thinning process of the display panel substrate, when a large-area panel is manufactured and is not cut, liquid crystal is poured into the panel. When the thinning process is performed, the low-concentration hydrofluoric acid is used for soaking and etching to achieve rapid thinning. However, the initial thinning process may cause process defects such as water ripples, bumps, pits, etc. with uneven thickness or irregular fine pattern traces. The fine defects are polished by polishing equipment (provided with a polishing pad) and grinding slurry to perform detail grinding on the substrate, so as to further improve the thickness uniformity of the substrate, and the polishing is performed to eliminate pattern traces (also called Mura) left on the substrate due to defects in the manufacturing or transmission process between different processes, so that the thickness and surface traces of the final substrate can meet the requirements of specifications. After the polishing process is completed, the substrate is rinsed with a clean water source (such as RO water or DI water) to remove the substrate from the polishing apparatus, and the rinsing action can remove the polishing slurry waste liquid remaining on the substrate, i.e., the polishing apparatus, and the used polishing slurry waste liquid is discharged to a waste liquid dedicated pipeline or collected in a waste liquid tank, which can be used as a manufacturing raw material of the waste liquid recycling system 100, i.e., the initial slurry waste liquid RS mentioned herein.

Referring to fig. 1, the waste liquid recovery system 100 includes an agitation tank 102, a motor 104, an agitator 106, a filter 108, a pressurizing pump 122, a specific gravity gauge 124, a water pressure gauge 126, a water level gauge 128, and a controller 140. In some embodiments, the waste recovery system 100 may omit one or more of the elements listed above. In some embodiments, the waste recovery system 100 may add one or more additional elements, such as a plurality of filters. In one embodiment, the waste recovery system 100 further comprises pipes 111, 113, 115, 117, 119, 131, 133, 135, and corresponding valves 112, 114, 116, 118, 120, 132, 134, 136. In one embodiment, the valves 112, 114, 116, 118, 120, 132, 134, 136 are used to control the opening and closing of their corresponding pipes 111, 113, 115, 117, 119, 131, 133, 135.

In one embodiment, the slurry tank 102 includes a first inlet connected to the pipe 111 for receiving the initial slurry waste RS, i.e., the used slurry and the slurry waiting to be recycled. The various slurry effluents delivered from different sources to the agitation tank 102 for mixing or agitation are collectively referred to herein as slurry effluent SS. The stirred tank 102 has a tank body which may be cylindrical, polygonal cylindrical, or other suitable shape and has a pointed conical body at the bottom. The agitation tank 102 may be made of stainless steel, concrete, ceramic, resin, or other suitable material, and the tank body may further include multiple layers of material, such as an anti-corrosion layer, to avoid reaction with the slurry waste SS component located in the agitation tank 102.

The agitation tank 102 is provided with an agitator 106, and the waste liquid recovery system 100 is provided with a motor 104 connected to the agitator 106 and driving the agitator 106. After the initial slurry waste RS is transferred to the stirring tank 102 to become the slurry waste SS, the stirrer 106 rotates at a predetermined rotation speed to stir the slurry waste SS. In one embodiment, the motor 104 may comprise a different type of motor, such as a servo motor, a stepper motor, a brushless motor, a dc motor, or any other suitable motor. The agitator 106 may include a shaft portion connected to the motor 104 and supporting the agitation portion, and an agitation portion driven by the motor 104 to rotate the agitation portion to agitate the slurry waste SS. In one embodiment, the stirring section may have different shapes, such as a fan-shaped, rod-shaped, or other suitable shape. In an embodiment, the agitation tank 102 further includes a bubble pipe, wherein the bubble pipe is used for introducing gas into the tank body, so that the bubbles can promote the solid or powder in the slurry waste SS to keep suspended so as not to precipitate. The gas introduced may be a clean air source (CDA) or nitrogen.

In one embodiment, the stirred tank 102 is connected to the filter 108 via lines 113 and 115. In the recovery process, the slurry waste SS is sent to the outlet of the agitation tank 102 and then sent to the filter 108 through the pipe 113, and the filtered water FW and the concentrated slurry waste FS are separated by the filter 108. Filter 108 is connected to line 117, wherein line 117 is opened and closed by valve 118 and filtered water FW can be drained via line 117. The concentrated slurry waste FS is returned from the filter 108 to the stirring tank 102 via the pipe 115 via the second inlet of the stirring tank 102 and collected as slurry waste SS, and the stirring-concentrating cycle is continued. In this case, the valves 120, 132, 134, 136 may be closed, and the valves 114, 116, 118 are opened, so that the slurry waste SS and the concentrated slurry waste FS circulate through the pipes 113, 115.

In one embodiment, the valve 112 controls the pipe 111 to be opened while the stirring tank 102 and the filter 108 are performing the stirring-concentrating step, so that the initial slurry waste RS can be continuously transmitted to the storage tank 102 through the pipe 111. In another embodiment, the valve 112 closes the pipe 111 to stop the transmission of the initial slurry waste RS to the storage tank 102 when the stirring tank 102 and the filter 108 perform the stirring-concentrating cycle.

In one embodiment, the pipeline 113 is routed by a pressure pump 122 to increase the pressure to accelerate the transportation efficiency of the slurry waste SS in the pipeline 113 and increase the output of the waste fluid recovery system 100. The booster pump 122 may be comprised of various forms of pumping, such as centrifugal, submersible, axial, mixed flow, vortex, and the like. In addition, the pipeline 113 may also be provided with a water pressure gauge 126 for sensing the hydraulic pressure of the slurry waste SS in the pipeline 113 to determine whether the delivery rate of the slurry waste SS or the hydraulic pressure of the pipeline 113 is within a normal range, so as to regulate and control the parameters of the pressure pump 122 to control the hydraulic pressure of the pipeline 113.

In one embodiment, the waste fluid recycling system 100 includes a specific gravity meter 124 disposed on the stirring tank 102 for sensing the solid content or specific gravity of the slurry waste fluid SS. In one embodiment, the specific gravity gauge 124 may include a sensing terminal extending into the interior of the agitation tank 102 for sensing the solid content of the slurry waste SS. The specific gravity meter 124 may further include a display module or a circuit module, which extends to the outside of the stirring tank 102 for maintenance or reading the sensed value. The specific gravity gauge 124 may be comprised of various forms of specific gravity gauges, such as float, static pressure, vibration or other forms of specific gravity gauges.

In one embodiment, the waste fluid recycling system 100 includes a water level gauge 128 disposed in the stirring tank 102 for sensing the level of the slurry waste fluid SS. The valve 112 can control the delivery amount of the initial slurry waste liquid RS by opening or closing the pipeline 111 according to the level of the slurry waste liquid SS sensed by the water level gauge 128.

Fig. 2 is a schematic diagram of a filter 108, drawn in accordance with some embodiments. In one embodiment, the filter 108 is a tangential flow filter (or cross-flow filter, cross-flow filter). In one embodiment, filter 108 includes a channel 202, a filter membrane 204, and a filtered water outlet 206. The passage 202 is used to allow the input slurry waste SS to rapidly pass through the filter 108, separate filtered water FW and concentrated slurry waste FS, and output the filtered water FW and the concentrated slurry waste FS through a filtered water outlet 206 and an outlet of the passage 202, respectively. The filter membrane 204 may be comprised of a hollow fiber membrane, a spiral filter membrane, a filter plate, or other suitable filter membrane. The tangential flow filtration method used in the filter 108 is a method in which the flow direction of the filtration target (slurry waste liquid SS) is different from the flow direction of the filtered water FW, for example, the two directions are substantially perpendicular to each other. Therefore, when the slurry waste SS is filtered, the macromolecular polishing powder or other particles are not easily stuck on the surface of the filter membrane 204, but can be scattered along with the flow of the slurry waste SS, and the concentrated slurry waste FS cannot generate a large colloidal reaction to affect the fluidity.

The filter 108 of fig. 2 is merely an example, and other filtering methods that can be used to separate the slurry waste SS can be used as the filtering element of the waste fluid recycling system 100.

Referring to fig. 1, the waste recovery system 100 includes a line 135, controlled by a valve 136, branching off a third inlet connected to the stirred tank 102 in the path of line 113. In one embodiment, the initial slurry waste RS is used to perform a bubble removal process through the pipe 135 to remove the gas accumulated in the agitation tank 102 or the pipe 113 before the waste fluid recycling system 100 performs the filtering or concentrating mode. In this case, the valves 114, 116, 118, 120, 132, 134 may be closed, while the valves 112, 136 are opened, so that the initial slurry waste RS is exhausted via the line 135. During the bubble removal process, the slurry waste RS can be recycled into the agitation tank 102 and the pipeline 113, and the accumulated gas can be discharged from the agitation tank 102 to the waste recovery system 100.

In one embodiment, when the agitation tank 102 and the filter 108 perform the above-mentioned agitation-concentration cycle for a period of time such that the concentration of the polishing powder (herein, collectively referred to as the solid content or solid content, which may be defined as the weight ratio of the solid content of the slurry waste SS to the total weight of the slurry waste SS) reaches a predetermined value after the slurry waste SS is concentrated, further processing, such as direct output or a next mixing procedure, may be performed. In one embodiment, the waste fluid recycling system 100 includes a pipe 119 controlled by a valve 120, wherein the pipe 119 is connected to the pipe 113 for outputting the concentrated slurry waste fluid SS as the finished slurry CS. In this case, the valves 112, 114, 116, 118, 132, 134, 136 may be closed, and the valve 120 is opened, so that the slurry waste SS is outputted as the finished slurry CS via the pipes 113, 119.

In one embodiment, the waste fluid recycling system 100 includes a pipe 131 controlled by a valve 132, wherein the pipe 131 is connected to the fourth inlet of the agitation tank for introducing the supplementary polishing powder NP into the agitation tank 102 for mixing. In one embodiment, the polishing powder NP comprises only abrasive particles, is in a solid state, and contains no moisture or other liquids. In this case, the valves 112, 114, 116, 118, 120, 134, 136 may be closed and the valve 132 opened, so that the slurry waste SS is mixed with the supplementary polishing powder NP. After the mixing process is completed, the valves 112, 114, 116, 118, 132, 134, 136 may be closed, and the valve 120 may be opened, so that the slurry waste SS is output as the completed slurry CS through the pipes 113, 119.

In one embodiment, the waste recovery system 100 includes a line 133 controlled by a valve 134, wherein the line 133 is connected to the filter 108 for performing a backwashing process of the filter 108. In one embodiment, after the stirring tank 102 and the filter 108 are subjected to the stirring-concentrating cycle for a certain period of time, the surface of the filter membrane 204 in the filter 108 may still accumulate a part of the solid content, such as polishing powder particles, thereby reducing the filtering efficiency of the filter 108. Thus, line 133 can be used to deliver wash water BW or wash liquid to filter 108 to remove the solid content adhering to the surface of filter membrane 204. In one embodiment, referring to fig. 1 and 2, the wash water BW or wash liquid is fed back into the filter membrane 204 through the filtered water outlet 206 and exits the waste recovery system 100 through the channel 202 to the conduit 113 and the conduit 119. During the backwash sequence, valves 112, 116, 118, 132, 136 may be closed and valves 114, 120, 134 opened, allowing the wash water BW and the solids content of the filter membrane 204 to drain through lines 113, 119. In one embodiment, since the drainage of the filtered water FW in the filtering or concentrating mode and the input of the cleaning water BW in the backwashing process do not overlap, the pipeline 117 and the pipeline 133 can be shared, and the valves 118 and 134 can be reduced to one, and in use, the filtered water FW is drained from the filtered water outlet 206 to the outside through the shared pipeline when the filtering or concentrating mode is performed; when the backwashing process is performed, the washing water BW is inputted from the outside to the filtered water outlet 206 through the common pipe to perform the washing operation.

In one embodiment, the waste fluid recovery system 100 includes a controller 140 configured to control the processes of filtering, concentrating, bubbling, backwashing, mixing, and outputting described above. In one embodiment, the controller is connected to the specific gravity gauge 124, the water pressure gauge 126 or the water level gauge 128 to sense the state of the waste slurry SS in the agitation tank 102 and the pipeline 113. In one embodiment, the controller 140 is coupled to the valves 112, 114, 116, 118, 120, 132, 134, 136 and transmits commands to open or close the valves to control the opening and closing of the lines 111, 113, 115, 117, 119, 131, 133, 135. In another embodiment, the controller 140 is connected to the pressure pump 122 or the motor 104 to control the pressure of the slurry waste SS or the rotation speed of the slurry waste SS. The connection between the controller 140 and the elements of the waste liquid recycling system 100 may be physical or electrical, and may be a wired or wireless connection, so that the sensing-regulating-executing-re-sensing loop can be continuously performed to maintain the normal operation of the various programs executed by the waste liquid recycling system 100.

The controller 140 may be formed by hardware plus software, for example, an Application Specific Integrated Circuit (ASIC) or a Field Programmable Gate Array (FPGA). The controller 140 may also be in the form of a computer, microcontroller, server, etc. and may include a processor and memory to store, call, and execute source code to perform the predetermined recycling steps for the waste fluid recycling system 100. The controller 140 may be separate from the waste stream recovery system 100 and connected to the waste stream recovery system 100 by wire or wirelessly, or integrated into the waste stream recovery system 100.

Fig. 3 is a flow diagram of a waste recovery method 300, according to some embodiments. The flow chart illustrated in fig. 3 is merely an example, and thus, in some embodiments, additional steps may be provided before, concurrently with, or after the various steps exemplified by the method 300. In other embodiments, one or more steps of method 300 may be replaced or deleted. In one embodiment, the order of the steps included in method 300 may be interchanged.

Fig. 4A-4G are schematic diagrams illustrating operation of various stages of the waste recovery system 100 according to some embodiments, where the stages represented in fig. 4A-4G may correspond to various steps in the method 300. Fig. 5 is a graph depicting the variation in solids content of the slurry effluent SS at various stages of the effluent recovery process 300, in accordance with certain examples.

When the waste liquid recycling method 300 starts, step 302 is entered, and the bubble discharging procedure is performed, the corresponding operation stage can be referred to fig. 4A and is represented by paths F1 and F2 in fig. 4A. When the bubble removal process is performed, the initial slurry waste RS is delivered to the agitation tank 102, and the bubble removal process is performed on the agitation tank 102 through the pipes 113 and 135 to remove the excess gas from the agitation tank 102 or the pipes. In one embodiment, the bubble draining program execution time is a period P0 (in seconds) from the beginning to the time T1. During the bubble discharge sequence, the booster pump 122 is operated at a low speed to facilitate the discharge of air from the line. In executing the bubble removal process, the controller 140 opens the booster pump 122 and the valves 112 and 136, and closes the valves 114, 116, 118, 120, 132, and 134, so that the slurry waste SS together with the gas is discharged through the circulation of the pipes 113 and 135. When the bubble removal process is performed, the solid content of the slurry waste SS in the agitation tank 102 is determined by the solid content value (or the corresponding specific gravity value) C1 of the initial slurry waste RS, wherein the solid content value C1 is maintained at a fixed value or within a fixed range. In one embodiment, the solid content value C1 is between 0.01% and 5%, between 0.1% and 5%, or between 0.1% and 2%. In one embodiment, the solids content value C1 is not higher than a predetermined initial solids content setpoint CX, wherein the initial solids content setpoint CX may be between 2% and 5%.

At step 304, the bubble removal process is stopped, and the initial slurry waste RS is continuously delivered to the agitation tank 102, and the corresponding operation stage can be referred to FIG. 4B and is represented by a path F2 in FIG. 4B. In one embodiment, the solid content value C1 of the initial slurry waste RS is fixed or lower than the initial solid content setting value CX within a predetermined range. In one embodiment, the process of delivering the initial slurry waste RS is performed during a period P1 (in seconds) from time T0 to time T1. In the period P1 of conveying the initial slurry waste liquid RS, the booster pump 122 returns to normal speed operation to accelerate the conveyance of the slurry waste liquid SS. In the period P1, the controller 140 closes the valves 114, 116, 118, 120, 132, 134, 136 by opening the pressure pump 122 and the valve 112, so that the slurry waste SS can enter the agitation tank 102. In one embodiment, step 304 is performed until the slurry waste SS in the agitation tank 102 reaches the predetermined water level L1 or a predetermined range, for example, a height range of 5%, 10%, 20% above or below the water level L1, and the valves 114, 116, 118 are opened to enter the filtration mode. In one embodiment, during the period P1 of step 304, the valves 114, 116, 118 are opened to enter the filtering mode early. In the period P1, the controller 140 controls the input amount of the initial slurry waste RS through the sensing of the water level gauge 128 and the control of the valve 112, so that the slurry waste SS in the stirring tank 102 reaches the water level L1 or a predetermined range, for example, a height range of 5% or 10% above or below the water level L1.

In step 306, the filtering mode is performed during a period P2 (in seconds) from time T1 to time T2. The corresponding working phase can be seen in fig. 4C, which is represented by paths F2, F3, F4 in fig. 4C. When the filtration mode is performed, the slurry waste SS is filtered along a circulation path formed by the agitation tank 102, the filter 108, and the pipes 113, 115, and 117. In the filtering mode performed in the period P2, since the excessive water in the slurry waste SS discharged from the filter 108 becomes the filtered water FW, the solid content of the concentrated slurry waste FS is larger than that of the initial slurry waste RS. When the concentrated slurry waste fluid FS circulates along the pipe 115 on the path F3 into the agitation tank 102, the solid content of the slurry waste fluid SS in the agitation tank 102 rises. In one embodiment, in the filtering mode, the controller 140 continuously or intermittently inputs the initial slurry waste RS into the agitation tank 102 through the sensing of the water level gauge 128 and the control of the valve 112, so that the water level of the slurry waste SS in the agitation tank 102 is maintained within a fixed water level L1 or a predetermined range, for example, within a height range of 5%, 10%, 20% above and below the water level L1.

In an embodiment, referring to fig. 4C and fig. 5, since the concentrated slurry waste fluid FS is recycled and re-enters the agitation tank 102, the ratio of the filtered water FW is reduced, such that the solid content of the slurry waste fluid SS in the agitation tank 102 temporarily rises, and the water level may temporarily fall. At this time, the controller 140 senses the drop of the water level via the water level meter 128, and may open the valve 112 to input more initial slurry waste liquid RS, since the solid content of the initial slurry waste liquid RS is lower than that of the concentrated slurry waste liquid FS, so that the solid content of the slurry waste liquid SS in the agitation tank 102 temporarily drops, and the water level is caused to rise again. In one embodiment, when the controller 140 senses that the water level rises back to the predetermined range through the water level gauge 128, the valve 112 is partially closed or completely closed to reduce or completely stop the initial slurry waste liquid RS from entering the agitation tank 102, so that the water level of the slurry waste liquid SS in the agitation tank 102 is maintained at the height L1 or within a predetermined range. Therefore, in the filtration mode, the slurry waste SS in the agitation tank 102 may exhibit an increase in solid content once or more than once and a decrease once or more than once. In one embodiment, the slurry waste SS in the agitation tank 102 has a solid content that shows one or more sets of ascending and descending staggered changes in the period P2.

In one embodiment, the slurry effluent SS in the stirred tank 102 has a solid content (or equivalent specific gravity value) from the solid content value C1 at time T1 to the solid content value C2 at time T2, and the solid content value C2 is greater than the solid content value C1, through the filtration mode performed in the period P2. In an embodiment, the solid content value C2 is between 2% and 12%, between 5% and 12%, or between 5% and 8%. In one embodiment, the ratio of the solids content value C2 to the solids content value C1 is between 10 and 400, between 20 and 200, or between 20 and 80.

In one embodiment, step 304 is omitted and the filtering mode of step 306 is entered directly after the bubble removal process of step 302. In other words, at the end of the period P0, the controller 140 continuously delivers the initial slurry waste RS to the agitation tank 102 by increasing the rotation speed of the pressure pump 122 and opening the valves 112, 114, 116, 118 and further closing the valves 132, 134, 136, while the slurry waste SS enters the filter 108 for filtration.

At step 308, the rich mode is performed during a period P3 (in seconds) from time T2 to time T3, and the corresponding operating phase is shown in FIG. 4D and represented by paths F3 and F4 of FIG. 4D. When the filtering mode proceeds to a stage, thus triggering the conditions of the rich mode, the filtering mode is ended and the rich mode is entered. The condition for triggering the concentration mode may be a predetermined time period P2 or a predetermined solid content value C2, and when any one of the conditions is met, the concentration mode may be considered to be entered. In the concentration mode, the slurry waste SS is concentrated along the agitation tank 102, the filter 108, and the pipes 113, 115, and 117. The concentration mode is similar to the filtration mode in that the filter 108 discharges excess water in the slurry waste SS as filtered water FW, so that the concentrated slurry waste FS has a solid content greater than that of the initial slurry waste RS.

The most significant difference between the concentration mode and the filtration mode is that the concentration mode stops sending the initial slurry waste liquid RS to the agitation tank 102, so in the concentration mode, the total amount of the solid content of the slurry waste liquid SS in the waste liquid recovery system 100 is not substantially increased, but since the filter 108 continues to perform the circulating concentration of the slurry waste liquid SS, the excess water in the slurry waste liquid SS is continuously filtered out as the filtered water FW and discharged, so that the solid content of the slurry waste liquid SS in the agitation tank 102 continuously increases, but the water level continuously decreases from the water level L1 or the original predetermined range. In one embodiment, in the concentration mode, the controller 140 stops the initial slurry waste RS from entering the agitation tank 102 under the control of the valve 112, and monitors that the water level of the slurry waste SS in the agitation tank 102 is not lower than the water level L2 or within a predetermined range, for example, within a height range of 5% or 10% from the upper side or the lower side of the water level L2, by the sensing of the water level gauge 128.

In one embodiment, referring to fig. 4D and 5, when the concentrated slurry waste fluid FS is returned to the stirring tank 102, the ratio of the filtered water FW is decreased, so that the solid content of the slurry waste fluid SS in the stirring tank 102 is increased and the water level is decreased. At this time, since the initial slurry waste liquid RS is not replenished, the solid content of the slurry waste liquid SS in the agitation tank 102 is continuously increased and is not decreased. On the other hand, in the concentration mode, the water level in the agitation tank 102 is continuously lowered only, and is not raised. In one embodiment, the solid content of the slurry waste SS in the agitation tank 102 continuously increases and the water level continuously decreases in the filtration mode, which is significantly different from the staggered variation of one or more sets of increases and decreases in the solid content or water level of the slurry waste SS in the agitation tank 102 in the filtration mode.

In one embodiment, the slurry waste SS in the agitation tank 102 has a solid content (or equivalent specific gravity value) from the solid content value C2 at the time T2 to the solid content value C3 at the time T3, and the solid content value C3 is greater than the solid content value C2 by the concentration mode performed in the period P3. In an embodiment, the solid content value C3 is between 6% and 20%, between 8% and 20%, or between 8% and 15%.

In one embodiment, the ratio of the solid content value C3 to the solid content value C2 is between 1.01 and 4, between 1.01 and 2, or between 1.1 and 2. In one embodiment, period P2 is greater than period P3.

In one embodiment, the ratio of period P2 to period P3 is between 10 and 45, between 15 and 45, or between 15 and 30.

Referring to fig. 4C, 4D and 5, the filtration mode and the concentration mode proposed in the present application can achieve the best production efficiency for recovering the initial slurry waste RS. In one embodiment, the filtration mode may be used in conjunction with the filter 108 to provide a progressive cycle of filtration and concentration of the spent grinding fluid SS. In one embodiment, since the initial slurry waste RS has a low solid content, if the tangential flow type filter 108 is used alone for filtration and concentration, the range of the solid content of the input slurry waste SS is not properly adjusted for the filter 108, and the desired solid content required for completing the slurry CS cannot be achieved within the period P1 of a short time, the length of the period P1 needs to be increased, which is likely to cause adverse effects on the filter 108, such as the clogging of the filter membrane 204, thereby reducing the service life of the filter membrane 204, or the backwashing of the filter membrane 204 needs to be performed more frequently to recover the filtering function of the filter 108. Accordingly, in the filtration mode, the initial slurry waste liquid RS is appropriately supplemented by continuously monitoring the rate of change of the solid content of the slurry waste liquid SS, so that the solid content of the slurry waste liquid SS can be stably increased and the filter 108 can be protected for the best service life.

On the other hand, when the filtration mode is performed for a certain period of time (for example, period P2) and the solid content of the slurry waste SS has reached the level of the solid content value C2 and the excess water content thereof has decreased by a large amount, the concentration mode is performed to filter and concentrate the slurry waste SS without replenishing the initial slurry waste RS, and the removal of the remaining water from the slurry waste SS can be accelerated. Moreover, compared with the filtration mode, a larger proportion of the excessive moisture can be removed in a shorter time, and the filtration and concentration time of the filter 108 in the high-concentration slurry waste liquid SS is shortened, that is, the length of the period P3 is smaller than that of the period P2, so that the filter 108 is protected from being easily clogged, the frequency of the backwashing process of the filter membrane 204 can be reduced, and the service life of the filter 108 can be prolonged. In one embodiment, the initial solid content value C2 at the beginning and the target solid content value C3 at the end of the concentrating mode and the period length P3 for the filter 108 to operate effectively with the input solid content continuously rising are taken into account when determining to enter the concentrating mode. The range of desired values of the above parameters needs to be considered together to determine the optimal starting solid content value C2, the target solid content value C3 at the end, and the period P3 of the rich mode. As such, the concentration mode can quickly increase the solid content of the slurry waste SS without damaging the life of the filter 108, thereby improving the recovery efficiency and maintenance cost of the waste fluid recovery system 100. In one embodiment, the duty cycle P2 or P3 of the filtering mode or the concentrating mode is not predetermined in advance, but the controller 140 determines the length of the period P2 or P3 according to the solid content value of the slurry waste SS in the filtering mode or the concentrating mode and the variation thereof, and determines to stop the filtering mode or the concentrating mode when the solid content value of the slurry waste SS reaches a predetermined value, such as the solid content value C2 or C3.

In the filtration mode, the average rate V2 of change in the solid content or specific gravity of the slurry waste SS can be determined by the length of the period P2 and the amount of change in the solid content. For example, the average rate V2 may be defined as V2= (C2-C1)/P2 (unit is%/second). Similarly, in the concentration mode, the average rate V3 of change of the solid content or specific gravity of the slurry waste SS can be determined by the length of the period P3 and the change amount of the solid content. For example, the average rate V3 may be defined as V3= (C3-C2)/P3 (unit is%/second). As is clear from the above description of the filtration mode and the concentration mode, the concentration mode is performed with higher efficiency of removing excess water than in the filtration mode, and thus the relationship of V3> V2 can be obtained. In one embodiment, the average rate V2 is between 0.1 and 0.8, between 0.2 and 0.8, or between 0.2 and 0.5. In one embodiment, the average rate V3 is between 1 and 20, between 3 and 20, or between 3 and 10. In one embodiment, the ratio of the average rate V3 to the average rate V2 is between 5 times and 100 times, between 5 times and 50 times, or between 10 times and 50 times.

At step 310, a backwashing process of the filter 108 is performed, and a corresponding operation phase can be referred to fig. 4E and is represented by a path F5 in fig. 4E. In one embodiment, the backwash process may be performed at the end or in the middle of the filtration mode or the concentration mode. As shown in fig. 4E, when the controller 140 finds that the filtering effect of the filter 108 is lower than a predetermined value, for example, the discharge rate of the filtered water FW is lower than a predetermined value, it can be judged that the filter membrane 204 of the filter is likely to be clogged to some extent, and therefore, the backwashing process is necessary. In performing the backwashing process, the controller 140 opens the valves 114, 120, 134 by closing the valves 112, 116, 118, 132, 136 so that the cleaning water BW can be reversely fed into the filter membrane 204 of the filter 108 through the line 133 to remove the solid content adhered to the filter membrane 204 of the filter 204 and discharge the wastewater with the blockages and the cleaning water through the lines 113, 119. When the controller 140 performs the backwashing process for a predetermined time or by sensing that the solid content of the discharged wastewater is lower than a predetermined value, the backwashing process may be stopped to return to the previous filtering mode or concentrating mode or to the next stage. In one embodiment, the cycle length of the backwashing process is between 300 seconds and 900 seconds.

In step 312, the mixing mode is performed in a period P4 (unit is seconds), the period P4 is performed between time T3 and time T4, and the corresponding working phase can be referred to fig. 4F and is represented by a path F6 in fig. 4F. When the concentration mode is carried out to a stage, and the condition of completing the concentration mode is triggered, the concentration mode is ended, and the concentrated grinding slurry waste liquor SS is directly output or the mixing mode is entered. The above-mentioned condition for ending the concentration mode may be that the predetermined time period P3 is ended, or that the solid content of the slurry waste SS reaches the predetermined solid content value C3, and when any one of the conditions is met, the concentration mode may be regarded as ending. Upon entering the mixing mode, the controller 140 opens the valve 132 by closing the valves 112, 114, 116, 118, 120, 134, 136 and the pressure pump 122, so that the supplementary slurry NP can enter the stirring tank 102 via the pipe 131 to be stirred with the slurry waste SS. In one embodiment, in the mixing mode, the controller 140 controls the input of the supplementary polishing powder NP via the control of the valve 132, and monitors whether the solid content in the slurry waste SS in the agitation tank 102 reaches the predetermined solid content value C4 by the sensing of the specific gravity meter 124. In the mixing mode, the water level of the agitation tank 102 may rise from the water level L2 to the level of the water level L3 due to the addition of the supplementary polishing powder NP.

In an embodiment, the solid content (or equivalent specific gravity value) of the slurry waste SS in the agitation tank 102 is from the solid content value C3 at the time T3 to the solid content value C4 at the time T4 by the mixing mode performed in the period P4, and the solid content value C4 is greater than the solid content value C3. In an embodiment, the solids content value C4 is between 6% and 30%, between 6% and 20%, or between 8% and 20%. In one embodiment, the ratio of the solids content C4 to the solids content C3 is between 1.01 and 2, between 1.1 and 2, or between 1.1 and 1.3.

At step 314, the output of the slurry CS is completed, and the corresponding working phase can be referred to FIG. 4G and is represented by the path F7 in FIG. 4G. After the slurry waste SS completes the concentration mode of step 308 or the material mixing mode of step 312, the concentrated slurry waste SS is outputted as the completed slurry CS. In one embodiment, when the slurry waste SS completes the concentration mode of step 308, the slurry waste SS is directly outputted as a completed slurry CS, wherein the completed slurry CS can be mixed with the supplementary polishing powder NP in another device or another execution stage in the waste liquid recovery system 100 or other steps. When the finished slurry CS is outputted, the controller 140 opens the pressure pump 122 and the valve 120 by closing the valves 112, 114, 116, 118, 132, 134, 136, so that the finished slurry CS can be outputted through the pipes 113, 119.

Although the present embodiments and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure herein, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present disclosure. Accordingly, such processes, machines, manufacture, compositions of matter, means, methods, or steps, are intended to be included within the scope of the present application.

[ description of symbols ]

100: waste liquid recovery system

102: agitation tank

104: motor with a stator and a rotor

106: stirrer

108: filter

111: pipeline

112: valve gate

113: pipeline

114: valve gate

115: pipeline

116: valve gate

117: pipeline

118: valve gate

119: pipeline

120: valve gate

122: pressure pump

124: specific gravity meter

126: water pressure meter

128: water level meter

131: pipeline

132: valve gate

133: pipeline

134: valve gate

135: pipeline

136: valve gate

140: controller for controlling a motor

202: channel

204: filter membrane

206: filtered water outlet

300: method of producing a composite material

302: step (ii) of

304: step (ii) of

306: step (ii) of

308: step (ii) of

310: step (ii) of

312: step (ii) of

314: step (ii) of

C1: solid content value/specific gravity value

C2: solid content value/specific gravity value

C3: solid content value/specific gravity value

C4: solid content value/specific gravity value

F1: route of travel

F2: route of travel

F3: route of travel

F4: route of travel

F5: route of travel

F6: route of travel

F7: route of travel

P0: period of time

P1: period of time

P2: period of time

P3: period of time

P4: period of time

T0: time of day

T1: time of day

T2: time of day

T3: time of day

T4: time of day

BW: backwashing water

CS: complete the slurry

FW: filtered water

FS: concentrated slurry waste liquor

NP: replenishing polishing powder

And RS: initial slurry waste

And SS: waste liquid of grinding slurry

Claims (10)

1. A system for recovering slurry waste comprising:

the stirring tank is used for receiving the initial slurry waste liquid and stirring the slurry waste liquid in the stirring tank;

a filter for inputting the slurry waste liquid and outputting filtered water and concentrated slurry waste liquid;

the first pipeline is connected with the stirring tank and is used for conveying the initial grinding slurry waste liquid to a first inlet of the stirring tank;

the second pipeline is connected with the stirring tank and the filter and is used for conveying the waste slurry to the filter from the stirring tank;

a third pipeline connected to the agitation tank and the filter, and configured to convey the concentrated slurry waste from the filter to a second inlet of the agitation tank;

the first valve is used for opening and closing the first pipeline;

the hydrometer is arranged on the stirring tank and used for sensing the solid content of the grinding slurry waste liquid; and

a controller electrically connected to the first valve and configured to control the first valve.

2. The system of claim 1, further comprising:

the fourth pipeline is used for conveying the supplementary polishing powder to the stirring tank; and

and the second valve is used for opening and closing the fourth pipeline.

3. The system of claim 1, further comprising a water level gauge for sensing a level of the slurry waste in the stirred tank.

4. The system of claim 1, further comprising a booster pump in the path of the first conduit.

5. The system of claim 1, further comprising a fifth line connected to a filtered water outlet of said filter and adapted to perform a backwashing procedure on said filter.

6. The system of claim 1, further comprising a sixth line connecting said agitation tank and said filter and adapted to perform a bubble removal procedure.

7. The system of claim 1, wherein the controller is configured to determine a first cycle length of the system in a filtration mode and a second cycle length in a concentration mode.

8. The system of claim 7, wherein in the filtration mode, the slurry effluent has a solids content no greater than a first solids content value.

9. The system of claim 8, wherein at the end of the concentration mode, the slurry waste has a solids content greater than the first solids content value.

10. The system of claim 7, wherein the controller is configured to open the first valve to enter the filtration mode and maintain a level of the spent slurry within a predetermined range during the first period.

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