Electric spark working fluid purification device capable of achieving automatic cleaning

Abstract

The utility model discloses an electric spark working fluid purification device capable of being automatically cleaned, and relates to the technical field of working fluid filtration. A raw material liquid inlet of the ceramic membrane group is connected with the raw material tank through a filtering pipeline, the raw material liquid inlet and a concentrated liquid outlet of the ceramic membrane group are respectively provided with a first pressure sensor and a second pressure sensor, and a penetrating fluid outlet of the ceramic membrane group is provided with a third pressure sensor and a flow sensor; and the cleaning liquid tank and the ceramic membrane group are provided with cleaning liquid inlets. Pressure data are recorded in real time through the pressure sensor, the transmembrane pressure difference of a filtering system can be obtained, a polluted ceramic membrane in the purification process can be automatically cleaned, the cavitation effect of ultrasonic waves is enhanced through the synergistic effect of the ultrasonic waves and the nano bubbles, the combined crushing force of the ultrasonic waves and the nano bubbles on pollutants is increased, and the purification effect is improved. The problem that in the prior art, the cleaning effect of single ultrasonic cleaning is poor is solved.

Description

Technical Field

[0001] This utility model relates to the field of working fluid filtration technology, and in particular to an automatic cleaning electro-spark working fluid purification device. Background Technology

[0002] Electrical discharge machining (EDM) is a method of machining materials by utilizing the corrosion phenomenon generated during spark discharge. During the process, not only are metal particles ranging from a few micrometers to tens of micrometers produced, but also micrometer- or submicrometer-sized carbon black. These electro-erosion products contaminate the working fluid and alter its physicochemical properties, ultimately affecting processing efficiency and product precision. Therefore, measures must be taken to remove impurity particles so that the working fluid can be recycled.

[0003] Currently, ceramic membrane filtration is generally considered to be an effective way to purify EDM fluid. However, ceramic membranes are easily contaminated during the filtration process, which leads to a decrease in filtration efficiency and effectiveness. Although ceramic membranes can be cleaned, there are still some problems: single cleaning methods have limited effectiveness, such as ultrasonic cleaning, which requires a long cleaning time and is not very effective; the cleaning process requires manual operation. Utility Model Content

[0004] The purpose of this invention is to solve the problems in the prior art by proposing an electro-discharge working fluid purification device that can automatically clean and purify ceramic membranes and improve the cleaning and purification efficiency and effect.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An automatically cleanable EDM working fluid purification device includes:

[0007] Raw material tank;

[0008] The ceramic membrane module has its feed liquid inlet connected to the feed tank via a filter pipe, and its feed liquid inlet and concentrate outlet are respectively equipped with a first pressure sensor and a second pressure sensor, while its permeate outlet is equipped with a third pressure sensor and a flow sensor.

[0009] The cleaning fluid tank is connected to the cleaning fluid inlet of the ceramic membrane module via a cleaning pipe.

[0010] A micro-nano bubble generator is installed on the cleaning pipe to generate micro-nano bubbles and allow the micro-nano bubbles to enter the interior of the ceramic membrane module through the cleaning pipe.

[0011] Multiple multi-frequency ultrasonic transducers are arranged in a dot matrix on the inner wall of the ceramic membrane module to generate ultrasonic waves to clean the ceramic membrane inside the module.

[0012] Furthermore, the ceramic membrane module includes a housing and a ceramic membrane, with each multi-frequency ultrasonic transducer equally spaced on the inner wall of the housing.

[0013] Furthermore, the outer shell is provided with multiple micro-nano bubble inlets, each of which is closely arranged with a multi-frequency ultrasonic transducer. The inlet of the cleaning pipe is connected to each micro-nano bubble inlet so that the micro-nano bubbles can enter the interior of the outer shell through each micro-nano bubble inlet.

[0014] Furthermore, a circulation pipe is provided between the concentrate outlet of the ceramic membrane module and the raw material tank, and a second pressure sensor and a third solenoid valve are sequentially installed on the circulation pipe along the fluid direction.

[0015] Furthermore, it also includes a recovery tank, and a recovery pipeline is provided between the permeate outlet of the ceramic membrane module and the recovery tank, with a fifth solenoid valve installed on the recovery pipeline.

[0016] Furthermore, a collection pipe is provided on the recovery pipeline, and the connection between the collection pipe and the recovery pipeline is located between the third pressure sensor and the fifth solenoid valve. A filtrate detection collection box is provided at one end of the collection pipe, a sixth solenoid valve is provided on the collection pipe, and an optical sensor is provided on the filtrate detection collection box.

[0017] Furthermore, a first solenoid valve, a feed pump, and a second solenoid valve are sequentially installed on the filter pipe along the fluid direction.

[0018] Furthermore, a discharge pipe is provided on the circulation pipeline, and a fourth solenoid valve is provided on the discharge pipe. The connection between the discharge pipe and the circulation pipeline is located between the second pressure sensor and the third solenoid valve.

[0019] Furthermore, a cleaning pump and a seventh solenoid valve are installed on the cleaning pipeline.

[0020] Furthermore, it also includes a control terminal and multiple actuators connected to the control terminal. Each actuator is respectively installed on each pipeline. The control terminal is connected to the first pressure sensor, the second pressure sensor, the third pressure sensor, and the flow sensor to receive signals and control the action of each actuator. Each actuator controls the fluid flow in the pipeline.

[0021] The beneficial effects of this utility model are as follows:

[0022] In this invention, the automatically cleanable EDM working fluid purification device introduces a real-time detection and feedback control system. Pressure data is recorded in real time by a pressure sensor and transmitted to the control computer. The transmembrane pressure difference of the filtration system can be obtained by calculation, which can realize the automatic cleaning of the contaminated ceramic membrane during the purification process, improve the purification efficiency and effect of the ceramic membrane, extend the life of the ceramic membrane, and reduce manual operation.

[0023] This purification device utilizes the synergistic effect of ultrasound and nanobubbles to enhance the cavitation effect of ultrasound, increase the combined crushing force of ultrasound and bubbles on contaminants, and reduce the residence time of difficult-to-clean contaminants. Furthermore, the micro-nano bubble inlet is placed near the ultrasonic transducer, and the bubbles burst rapidly under pressure changes after exiting, generating instantaneous high-temperature and high-pressure shock waves, which can effectively peel off contaminants attached to the membrane surface and membrane pores. At the same time, by adjusting the frequency of ultrasound, it can achieve all-round cleaning of contaminants from large particles to nano-sized contaminants. This device uses a combination of multi-frequency ultrasound and micro-nano bubble technology, which solves the problem of poor cleaning effect of single ultrasonic cleaning in existing technologies. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of an automatically cleanable EDM working fluid purification device proposed in this utility model.

[0025] Figure 2 This is a cross-sectional structural diagram of the ceramic module of an automatically cleanable EDM working fluid purification device proposed in this utility model.

[0026] In the diagram: 1 Raw material tank, 2 Feed pump, 3 Ceramic module, 4 Micro-nano bubble inlet, 5 Multi-frequency ultrasonic transducer, 6 Micro-nano bubble generator, 7 Cleaning pump, 8 Cleaning liquid tank, 9 Filtrate detection and collection box, 10 Control terminal, 11 Recovery tank, 12 First solenoid valve, 13 Second solenoid valve, 14 First pressure sensor, 15 Second pressure sensor, 16 Third solenoid valve, 17 Fourth solenoid valve, 18 Third pressure sensor, 19 Fifth solenoid valve, 20 Flow sensor, 21 Sixth solenoid valve, 22 Optical sensor, 23 Seventh solenoid valve. Detailed Implementation

[0027] The technical solution of this patent will be further described in detail below with reference to specific embodiments.

[0028] The embodiments of this patent are described in detail below. Examples of these embodiments are shown 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 are only used to explain this patent, and should not be construed as limiting this patent.

[0029] In the description of this patent, it should be understood that the terms “center,” “upper,” “lower,” “front,” “back,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this patent.

[0030] In the description of this patent, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this patent according to the specific circumstances.

[0031] Example 1

[0032] Reference Figure 1-2 An automatic cleaning device for cleaning electrical discharge working fluid is used for cleaning and purifying ceramic membranes that filter electrical discharge working fluid. This device facilitates automated cleaning and purification of the ceramic membrane and improves the cleaning and purification effect.

[0033] The automatically cleanable EDM working fluid purification device includes a raw material tank 1, a ceramic membrane module 3, a cleaning fluid tank 8, a micro-nano bubble generator 6, and multiple multi-frequency ultrasonic transducers 5.

[0034] The feed liquid inlet of the ceramic membrane module 3 is connected to the feed tank 1 through a filter pipe. The filter pipe is equipped with a first solenoid valve 12, a feed pump 2 and a second solenoid valve 13 in sequence along the fluid direction. The feed pump 2 can pump the feed liquid in the feed tank 1 into the ceramic membrane module 3 through the filter pipe for filtration.

[0035] The ceramic membrane module 3 includes a shell and a ceramic membrane. After the feed liquid enters the ceramic membrane through the filter pipe, the feed liquid flows at high speed in a tangential manner across the membrane surface. Under pressure, the permeate passes through the membrane surface and is filtered out. A circulation pipe is provided between the concentrate outlet of the ceramic membrane module 3 and the feed tank 1. A second pressure sensor 15 and a third solenoid valve 16 are sequentially installed on the circulation pipe along the fluid direction. The concentrate returns to the feed tank 1 through the circulation pipe and enters the ceramic membrane module 3 again through the feed pump 2, so that the EDM working fluid is circulated and filtered by the ceramic membrane module 3. In this embodiment, the filtration direction of the ceramic membrane in the ceramic membrane module 3 is from the outside to the inside, that is, the feed liquid flows on the outside of the ceramic membrane and passes through the ceramic membrane under pressure, while the permeate is discharged from the inside of the ceramic membrane.

[0036] The permeate outlet of the ceramic membrane module 3 is connected to a recovery tank 11 via a recovery pipe. The filtered EDM working fluid can be recovered into the recovery tank 11. The recovery pipe is equipped with a fifth solenoid valve 19 and a collection pipe. The connection between the collection pipe and the recovery pipe is located between the third pressure sensor 18 and the fifth solenoid valve 19. One end of the collection pipe is equipped with a filtrate detection collection box 9. The collection pipe is equipped with a sixth solenoid valve 21. The filtrate detection collection box 9 can collect the filtered EDM working fluid. The filtrate detection collection box 9 is equipped with an optical sensor 22, which can detect the turbidity of the currently filtered EDM fluid.

[0037] The outer shell of the ceramic membrane module 3 is provided with a cleaning fluid inlet. The cleaning fluid tank 8 is connected to the cleaning fluid inlet of the ceramic membrane module 3 through a cleaning pipe. The cleaning pipe is equipped with a cleaning pump 7 and a seventh solenoid valve 23. The cleaning pump 7 can inject the cleaning fluid in the cleaning fluid tank 8 into the ceramic membrane module 3 through the cleaning fluid inlet of the ceramic membrane module 3, so that the cleaning fluid reaches the outside of the ceramic membrane for cleaning. In conjunction with the outside-to-in filtration method of the ceramic membrane in the ceramic membrane module 3, the pollutants filtered and intercepted on the ceramic membrane are effectively cleaned.

[0038] The micro-nano bubble generator 6 is installed on the cleaning pipe. The micro-nano bubble generator 6 can inject micro-nano bubbles into the cleaning pipe, which flow into the ceramic membrane module 3 along with the cleaning liquid in the cleaning pipe. The micro-nano bubble generator is an existing technology (such as model LF-1500) and can generate micro-nano bubbles. Its principle and installation method will not be described in detail here. The outer shell of the ceramic membrane module 3 is provided with multiple micro-nano bubble inlets 4. The inlet of the cleaning pipe is connected to each micro-nano bubble inlet 4, so that the micro-nano bubbles can enter the ceramic membrane module 3 along with the cleaning liquid through multiple micro-nano bubble inlets 4, thereby cleaning the ceramic membrane in the ceramic membrane module 3.

[0039] Each multi-frequency ultrasonic transducer 5 is arranged in a matrix on the inner wall of the ceramic membrane module 3, that is, it is evenly spaced on the inner wall of the outer shell of the ceramic membrane module 3. The multi-frequency ultrasonic transducer is an existing technology (such as model JYD-40-80-120) and can generate ultrasonic vibrations of multiple frequencies. Its principle and installation method will not be described in detail here. The ultrasonic waves generated by the multi-frequency ultrasonic transducer 5 clean the ceramic membrane inside the ceramic membrane module 3. And because it is evenly distributed in a matrix on the inner wall of the outer shell of the ceramic membrane module 3, the cleaning effect on the ceramic membrane is improved.

[0040] Furthermore, each micro-nano bubble inlet 4 is closely attached to a multi-frequency ultrasonic transducer 5. Since the micro-nano bubble inlet 4 is located near the ultrasonic transducer 5, the bubbles burst rapidly under pressure changes after they come out, generating instantaneous high temperature and high pressure shock waves, which can effectively peel off contaminants attached to the surface and pores of the ceramic membrane.

[0041] The circulation pipeline is equipped with a discharge pipe, and the discharge pipe is equipped with a fourth solenoid valve 17. The connection between the discharge pipe and the circulation pipeline is located between the second pressure sensor 15 and the third solenoid valve 16. When the fourth solenoid valve 17 is opened, the cleaning fluid after cleaning the ceramic membrane pores can be discharged through the discharge pipe.

[0042] The ceramic membrane module 3 is equipped with a first pressure sensor 14 and a second pressure sensor 15 at the feed liquid inlet and the concentrate outlet, respectively, and a third pressure sensor 18 and a flow sensor 20 at the permeate outlet. The pressures at the feed liquid inlet, concentrate outlet, and permeate outlet of the ceramic membrane module 3 can be measured using the first pressure sensor 14, the second pressure sensor 15, and the third pressure sensor 18, allowing for the calculation of the transmembrane pressure difference of the ceramic membrane module 3. The calculation formula is as follows:

[0043]

[0044] in:

[0045] P in : The pressure at the feed liquid inlet of ceramic membrane module 3, i.e., the reading of the first pressure sensor 14; P out The pressure at the outlet of the concentrate from ceramic membrane module 3 is the reading of the second pressure sensor 15.

[0046] P permeate : The pressure at the permeate outlet of ceramic membrane module 3, i.e., the reading of the third pressure sensor 18.

[0047] The formula for calculating the permeate flow rate of ceramic membrane module 3 is as follows:

[0048]

[0049] in:

[0050] Q is the flow rate (unit: L) measured by the flow sensor of the ceramic membrane module 3 permeation measurement, that is, the reading of the flow sensor 20;

[0051] A is the effective filtration area of ​​ceramic membrane module 3 (unit: m²). 2 );

[0052] t is the time interval (unit: h).

[0053] Example 2

[0054] An automatically cleanable EDM working fluid purification device is provided. To facilitate automatic control of cleaning of the EDM working fluid purification device, the device further includes a control terminal 10 and multiple actuators connected to the control terminal 10. Each actuator is distributed on a pipeline. The control terminal 10 is connected to a first pressure sensor 14, a second pressure sensor 15, a third pressure sensor 18, and a flow sensor 20. The control terminal 10 can receive signals and control the operation of each actuator. Each actuator includes a first solenoid valve 12, a second solenoid valve 13, a third solenoid valve 16, a fourth solenoid valve 17, a fifth solenoid valve 19, a sixth solenoid valve 21, and a seventh solenoid valve 23. Each actuator, i.e., each solenoid valve, controls the fluid flow in the corresponding pipeline for automatic cleaning.

[0055] The working principle of the automatically cleanable EDM working fluid purification device is as follows: First, the threshold values ​​of the core indicators when the ceramic membrane module 3 needs to be cleaned are set in the computer program of the control terminal 10: when the relative increase of the transmembrane pressure difference reaches 20% of the initial value, and when the permeate flow rate drops to 70% of the initial value, the auxiliary indicator for the ceramic membrane to be cleaned is set to the turbidity of the filtered EDM working fluid as 50 NTU.

[0056] When filtration is performed through the ceramic membrane module 3, the control terminal 10 controls the opening of the first solenoid valve 12, the second solenoid valve 13, the third solenoid valve 16, and the fifth solenoid valve 19, and controls the closing of the fourth solenoid valve 17, the sixth solenoid valve 21, and the seventh solenoid valve 23. Then, the EDM working fluid in the raw material tank 1 is driven by the feed pump 2 to flow through the filtration pipeline to the ceramic membrane module 3. After cross-flow filtration by the ceramic membrane module 3, the filtered EDM working fluid permeates from the membrane pores of the ceramic membrane module 3 to the recovery pipeline and flows to the recovery tank 11, while the concentrated liquid containing impurities flows back to the raw material tank 1 through the circulation pipeline for circulation, thereby completing the filtration of the EDM working fluid and purifying the working fluid.

[0057] During filtration, the first pressure sensor 14, the second pressure sensor 15, and the third pressure sensor 18 transmit pressure data to the control terminal 10 computer. The control terminal 10 computer calculates the real-time transmembrane pressure difference during the filtration process. The flow sensor 20 transmits flow data to the control terminal 10 computer. The control terminal 10 computer calculates the real-time permeate flow rate during the filtration process.

[0058] When the transmembrane pressure difference and permeate flow rate reach the previously set thresholds, it indicates that the ceramic membrane has become fouled. Combined with the turbidity index, the computer at the control terminal 10 controls the opening of the sixth solenoid valve 21 and the optical sensor 22. The filtered EDM working fluid enters the filtrate detection collection tank 9 through the collection pipe. The optical sensor 22 can detect the turbidity of the currently filtered EDM fluid to further verify the fouling status of the ceramic membrane in the ceramic membrane module 3. When the turbidity reaches the threshold range, the cleaning mode is triggered. The computer at the control terminal 10 controls the system to close the feed pump 2, the first solenoid valve 12, the second solenoid valve 13, the third solenoid valve 16, the fifth solenoid valve 19, and the sixth solenoid valve 21 to stop filtration.

[0059] Subsequently, the computer control system at the control terminal 10 opens the fourth solenoid valve 17 and the seventh solenoid valve 23, and starts the cleaning pump 7, the multi-frequency ultrasonic transducer 5, and the micro-nano bubble generator 6. The cleaning fluid is delivered to the ceramic membrane module 3 by the cleaning pump 7, and at the same time, the micro-nano bubbles generated by the micro-nano bubble generator 6 enter the ceramic module 3. Under the synergistic effect of ultrasonic waves and micro-nano bubbles, the ceramic membrane is cleaned. During the cleaning process, the frequency of the ultrasonic transducer 5 can be adjusted to achieve deep cleaning of the ceramic membrane at different frequencies. Finally, the cleaning fluid is discharged through the discharge pipe.

[0060] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. An automatically cleanable EDM working fluid purification device, characterized in that, include: Raw material tank (1); The ceramic membrane module (3) has its feed liquid inlet connected to the feed tank (1) via a filter pipe, and the feed liquid inlet and concentrate outlet of the ceramic membrane module (3) are respectively equipped with a first pressure sensor (14) and a second pressure sensor (15), and the permeate outlet of the ceramic membrane module (3) is equipped with a third pressure sensor (18) and a flow sensor (20). The cleaning liquid tank (8) is provided with a cleaning liquid inlet on the ceramic membrane assembly (3), and the cleaning liquid tank (8) and the cleaning liquid inlet of the ceramic membrane assembly (3) are connected through a cleaning pipe; A micro-nano bubble generator (6) is installed on the cleaning pipe to generate micro-nano bubbles and allow the micro-nano bubbles to enter the interior of the ceramic membrane assembly (3) through the cleaning pipe. Multiple multi-frequency ultrasonic transducers (5) are arranged in a dot matrix on the inner wall of the ceramic membrane group (3) to generate ultrasonic waves to clean the ceramic membrane inside the ceramic membrane group (3).

2. The automatically cleanable EDM working fluid purification device according to claim 1, characterized in that: The ceramic membrane assembly (3) includes a shell and a ceramic membrane, and each multi-frequency ultrasonic transducer (5) is equally spaced on the inner wall of the shell.

3. The automatically cleanable EDM working fluid purification device according to claim 2, characterized in that: The outer shell is provided with multiple micro-nano bubble inlets (4), each of the micro-nano bubble inlets (4) is arranged in close contact with a multi-frequency ultrasonic transducer (5), and the inlet of the cleaning pipe is connected to each of the micro-nano bubble inlets (4) so ​​that the micro-nano bubbles enter the interior of the outer shell through each of the micro-nano bubble inlets (4).

4. The automatically cleanable EDM working fluid purification device according to claim 1, characterized in that: A circulation pipe is provided between the concentrate outlet of the ceramic membrane module (3) and the raw material tank (1), and a second pressure sensor (15) and a third solenoid valve (16) are sequentially provided on the circulation pipe along the fluid direction.

5. The automatically cleanable EDM working fluid purification device according to claim 1, characterized in that: It also includes a recovery tank (11), and a recovery pipe is provided between the permeate outlet of the ceramic membrane module (3) and the recovery tank (11), and a fifth solenoid valve (19) is provided on the recovery pipe.

6. The automatically cleanable EDM working fluid purification device according to claim 5, characterized in that: The recycling pipeline is provided with a collection pipe, and the connection between the collection pipe and the recycling pipeline is located between the third pressure sensor (18) and the fifth solenoid valve (19). One end of the collection pipe is provided with a filtrate detection collection box (9), the collection pipe is provided with a sixth solenoid valve (21), and the filtrate detection collection box (9) is provided with an optical sensor (22).

7. The automatically cleanable EDM working fluid purification device according to claim 1, characterized in that: The filter pipe is provided with a first solenoid valve (12), a feed pump (2), and a second solenoid valve (13) in sequence along the fluid direction.

8. The automatically cleanable EDM working fluid purification device according to claim 4, characterized in that: The circulation pipeline is provided with a discharge pipe, and the discharge pipe is provided with a fourth solenoid valve (17). The connection between the discharge pipe and the circulation pipeline is located between the second pressure sensor (15) and the third solenoid valve (16).

9. The automatically cleanable EDM working fluid purification device according to claim 1, characterized in that: The cleaning pipeline is equipped with a cleaning pump (7) and a seventh solenoid valve (23).

10. The automatically cleanable EDM working fluid purification device according to claim 1, characterized in that: It also includes a control terminal (10) and a plurality of actuators connected to the control terminal (10). Each actuator is respectively disposed on each pipe. The control terminal (10) is connected to a first pressure sensor (14), a second pressure sensor (15), a third pressure sensor (18), and a flow sensor (20) to receive signals and control the operation of each actuator. Each actuator controls the flow of fluid in the pipe.

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