A device and method for detecting the pH value of a slurry for investment casting

Abstract

The application discloses a kind of investment casting slurry pH value cyclic detection device and method, it is related to pH value detection device technical field, device includes rack, installation on the lifting mechanism of rack, probe assembly and cleaning mechanism are installed in the lifting end of lifting mechanism;Cleaning mechanism includes cleaning cavity and liquid supply mechanism;Cleaning cavity is set on rack and its top surface is provided with the through hole of being threaded;Probe assembly can be slidably threaded into the through hole and block its top end orifice and bottom end orifice, while the detection end of probe assembly is located in the closed hole cavity of through hole;The cleaning pipeline of liquid supply mechanism is cyclically communicated closed hole cavity, for supplying cleaning fluid to clean the detection end of probe assembly;Lifting mechanism can drive the detection end of probe assembly to drop to the detection station below cleaning cavity to carry out pH value detection.The application can realize the in-situ, real-time, periodic full-automatic detection of investment casting slurry pH value.

Description

Technical Field

[0001] This invention relates to the field of pH value detection device technology, and in particular to a device and method for circulating pH value detection of investment casting slurry. Background Technology

[0002] In the field of investment casting, investment casting slurry is the core raw material for preparing the mold shell in precision investment casting. It is a viscous suspension colloidal system composed of refractory powder, binder, solvent, and various additives, and is the molding material that directly affects the quality of the casting. Its viscosity, pH value, rheological properties, and stability directly determine the uniformity and density of the mold shell. Therefore, in actual production, the pH value of the slurry, as an important parameter, needs to be monitored in real time.

[0003] Currently, most pH value detection of slurries is conducted offline, relying primarily on manual sampling, wiping, calibration, reading, and cleaning. However, slurries contain a large number of fine refractory solid particles such as zircon powder and corundum powder. During offline sampling and testing, these solid particles easily adhere to and deposit on the surface of the pH electrode glass membrane and at the interface with the reference liquid, causing micropore blockage. A single test can trigger electrode passivation and reference potential shift. If cleaning is incomplete, subsequent tests will suffer from continuous distortion and systematic data deviation. Frequent testing will also accelerate electrode wear and shorten electrode lifespan. Furthermore, the viscosity of slurries is much higher than that of ordinary aqueous solutions, significantly reducing ion migration rates. Ion exchange at the interface between the pH electrode glass sensitive membrane and the reference liquid is hindered, resulting in slower electrode response, prolonged reading drift, and difficulty in stabilizing the reading. While conventional aqueous solutions stabilize within seconds, offline slurry testing often requires tens of seconds or even longer, with slight fluctuations in the value, making it highly susceptible to human error. Moreover, viscous slurries easily form a coating layer on the electrode membrane surface, hindering hydrogen ion sensing and directly reducing detection sensitivity. Because sampling depth, electrode immersion depth, reading timing, and cleaning cleanliness are all subject to human error, and there is no standardized closed-loop process, the comparability of test data from different operators and at different times is poor, making it impossible to achieve precise and routine detection and control of slurry pH value.

[0004] Therefore, there is an urgent need in this field for a dedicated device and method for detecting the pH value of slurry, which can quickly and accurately detect the pH value of slurry, provide direct data support for the proportioning of raw and auxiliary materials in slurry, and thus improve the quality of shell molds and casting products. Summary of the Invention

[0005] In view of this, the present invention proposes a device and method for circulating detection of pH value of investment casting slurry, aiming to solve at least one of the above-mentioned technical problems.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This invention provides a device for circulating and detecting the pH value of investment casting slurry, comprising: frame; A lifting mechanism is installed on the frame; The probe assembly is installed at the lifting end of the lifting mechanism; A cleaning mechanism includes a cleaning chamber and a liquid supply mechanism. The cleaning chamber is mounted on the frame and has a through hole on its top surface. The probe assembly can slide through the through hole and seal its top and bottom openings, while the detection end of the probe assembly is located within the closed cavity of the through hole. The cleaning pipeline of the liquid supply mechanism is circulated through the closed cavity to supply cleaning liquid for cleaning the detection end of the probe assembly within the closed cavity. The lifting mechanism can drive the detection end of the probe assembly to descend to a detection position below the cleaning chamber for pH value detection.

[0008] This invention provides a cleaning chamber with through holes, allowing the probe assembly to slide through the through holes and seal its top and bottom openings, forming a closed cavity inside the through holes. The cleaning pipeline of the liquid supply mechanism is circulated and connected to this closed cavity, thus achieving in-situ closed cleaning of the probe detection end. This structure effectively removes slurry residue and solid particles adhering to the electrode surface, avoiding electrode passivation and data distortion caused by incomplete wiping and micropore blockage in existing offline testing. Simultaneously, a lifting mechanism drives the probe assembly to automatically switch between the testing station and the closed cavity, achieving a closed-loop process for testing and cleaning. This eliminates the need for traditional non-standardized operations such as manual sampling, wiping, calibration, and cleaning, and removes the drawback of poor comparability of test data from different operators and at different times. Furthermore, after testing, the probe end immediately enters the closed cavity for cleaning, preventing slurry from drying and coating the electrode surface. This eliminates the need for frequent manual wiping and calibration, significantly reducing electrode wear and extending electrode lifespan. The cleaning chamber integrates through-holes and a closed cavity, with the liquid supply mechanism connected via pipelines. The compact structure facilitates integration with existing investment casting production lines and is suitable for continuous industrial production scenarios.

[0009] As a further improvement to the above technical solution, the probe assembly includes a probe and a protective tube; the lower end of the protective tube is closed, the lower end of the probe is the detection end and is coaxially and sealed through the protective tube, and a liquid inlet cavity is formed inside the protective tube corresponding to the outer periphery of the detection end; a liquid inlet window is opened on the outer peripheral wall of the protective tube corresponding to the liquid inlet cavity, which communicates with the liquid inlet cavity; the protective tube can slide through the through hole and seal its top and bottom openings, while the liquid inlet cavity communicates with the closed cavity of the through hole through the liquid inlet window; the upper part of the protective tube is installed on the lifting end of the lifting mechanism.

[0010] The beneficial effects of the above technical solution are as follows: By setting a protective tube with a closed lower end outside the probe, and opening a liquid inlet window on the outer peripheral wall of the protective tube, a liquid inlet chamber is formed on the outer periphery of the probe's detection end, communicating with the closed cavity. During detection, the slurry enters the liquid inlet chamber through the liquid inlet window and contacts the detection end. During cleaning, the cleaning fluid enters the liquid inlet chamber through the closed cavity and the liquid inlet window to flush the detection end. Detection and cleaning are completed in the same station, without the probe needing to detach from the protective tube, resulting in a simple and efficient structure. Simultaneously, the protective tube encloses the probe's detection end, allowing it to contact the external medium only at the liquid inlet window. This prevents the probe from colliding with the slurry tank wall, cleaning chamber, etc., during lifting, moving, and station switching, improving the probe's operational safety. Furthermore, the liquid inlet window, as the only connecting channel between the liquid inlet chamber and the closed cavity, guides the slurry and cleaning fluid to flow steadily into the surface of the detection end during detection and cleaning, respectively. The fluid path is clear, ensuring the stability of the detection and cleaning effects.

[0011] As a further improvement to the above technical solution, a pneumatic drying mechanism is also included. The air supply pipeline of the pneumatic drying mechanism is connected to the closed cavity and is used to deliver drying gas into the closed cavity to dry the detection end of the probe.

[0012] The beneficial effects of the above technical solution are as follows: If the cleaning fluid remaining on the surface of the detection end after cleaning is carried into the slurry to be tested, it will dilute the slurry and change the local pH value, leading to distortion of the next test data. The pneumatic drying mechanism quickly dries the detection end by delivering high-pressure gas into the sealed cavity, eliminating the interference of water stains on the detection accuracy from the root. Compared with natural air drying or manual wiping, the pneumatic drying method can complete the drying in a few seconds, greatly shortening the waiting time between two tests and providing time guarantee for high-frequency, periodic cyclic testing. In addition, the drying process ensures that the detection end of the probe is in a clean and dry initial state before each test, ensuring that the starting conditions of each test are consistent, and significantly improving the repeatability and comparability of periodic retest data. At the same time, for high-viscosity media such as investment casting slurry, cleaning alone is not enough to completely remove the liquid film remaining on the surface of the detection end. Pneumatic drying, as a connecting step between cleaning and the next cycle test, effectively solves this industry pain point.

[0013] As a further improvement to the above technical solution, there are multiple liquid inlet windows; the multiple liquid inlet windows are arranged at intervals along the circumference of the protective tube; the outer peripheral wall of the cleaning chamber is provided with a liquid inlet and a liquid return port corresponding to the closed cavity; the liquid inlet and the liquid return port are arranged at intervals along the circumference of the cleaning chamber and correspond one-to-one with two liquid inlet windows. The liquid supply mechanism includes an inlet pipe, a return pipe, a circulation pump, and a waste liquid recovery and purification component; one end of the inlet pipe is connected to the inlet port, and the other end is connected to the clean liquid outlet of the waste liquid recovery and purification component; one end of the return pipe is connected to the return port, and the other end is connected to the waste liquid inlet of the waste liquid recovery and purification component; the circulation pump is installed on the inlet pipe and is used to circulate the cleaning liquid into the closed cavity and the inlet cavity to clean the detection end.

[0014] The beneficial effects of the above technical solution are as follows: By setting multiple circumferentially spaced inlet windows and correspondingly opening inlet and outlet ports on the outer peripheral wall of the cleaning chamber, the cleaning fluid can enter the sealed cavity from the inlet port and pass through the inlet windows from different circumferential directions into the inlet chamber, forming a multi-angle and all-round flushing of the detection end, eliminating cleaning dead corners; at the same time, the cleaning fluid is driven by a circulation pump to circulate between the sealed cavity, the inlet chamber, and the waste liquid recovery and purification component, realizing the repeated use of the cleaning fluid and reducing pure water consumption; and the waste liquid recovery and purification component centrally collects and purifies the waste liquid after cleaning, avoiding environmental pollution caused by the direct discharge of waste liquid containing solid particles such as zircon powder and corundum powder, thus meeting the requirements of green industrial production.

[0015] As a further improvement to the above technical solution, the waste liquid recovery and purification component includes a sedimentation overflow cover, a sedimentation overflow cylinder, and a collection tank; the sedimentation overflow cover, the sedimentation overflow cylinder, and the collection tank are connected in sequence from top to bottom; a waste liquid inlet is provided at the top center of the sedimentation overflow cover; and a clean liquid outlet is provided at the bottom of the collection tank.

[0016] The beneficial effects of the above technical solution are as follows: This invention, through a three-stage structure in which a settling overflow cover, a settling overflow cylinder, and a collection tank are connected sequentially from top to bottom, utilizes the density difference between solid particles and liquid in the waste liquid to achieve natural solid-liquid separation through three vertically connected settling spaces. No additional centrifugal or filtration power equipment is required, resulting in a simple structure and low operating costs. Solid impurities in the waste liquid are deposited step by step in each settling space, and the supernatant flows into the next stage through overflow, ultimately obtaining reusable purified water at the bottom of the collection tank, thus realizing the recycling and reuse of water resources.

[0017] As a further improvement to the above technical solution, a first-stage conical flow buffer plate is provided inside the sedimentation overflow cover below the waste liquid inlet; the outer periphery of the first-stage conical flow buffer plate is bent upward to form a first-stage sludge accumulation trough; the outer periphery of the first-stage conical flow buffer plate and the inner periphery of the corresponding sedimentation overflow cover are spaced apart to form an annular overflow zone. The bottom of the sedimentation overflow cover is detachably connected to the top of the sedimentation overflow cylinder; a slow-flow funnel is fixed to the inner circumferential wall of the sedimentation overflow cylinder; the upper port of the slow-flow funnel corresponds to the lower part of the annular overflow zone to collect overflow liquid; a secondary conical slow-flow plate is provided below the slow-flow funnel, and the outer circumferential side of the secondary conical slow-flow plate is bent upward to form a secondary sludge accumulation trough; the outer circumferential part of the sedimentation overflow cylinder is detachably connected to the top of the liquid collection tank; the secondary conical slow-flow plate is embedded in the liquid collection tank; the outer circumferential side of the secondary conical slow-flow plate and the corresponding inner circumferential side of the liquid collection tank are spaced apart to form an annular overflow zone two.

[0018] The beneficial effects of the above technical solution are as follows: By setting up a primary conical flow buffer and a secondary conical flow buffer respectively, the conical flow buffer plays a buffering, slowing and dispersing role on the downward flow of waste liquid, significantly reducing the flow velocity of waste liquid and providing sufficient settling time for solid particles, thus avoiding the problem of particles being entrained in the overflow liquid due to excessive flow velocity; the primary slag collection trough formed by the upward bending of the outer periphery of the primary conical flow buffer and the secondary slag collection trough formed by the upward bending of the outer periphery of the secondary conical flow buffer can effectively collect the deposited solid phase. The particles are trapped in the tank, and even if subsequent waste liquid continues to flow in, the settled particles will not be stirred up again by the liquid flow disturbance, ensuring the continuous stability of solid-liquid separation. At the same time, the annular overflow zone one formed between the outer periphery of the first-stage conical flow buffer plate and the inner periphery of the settling overflow cover, and the annular overflow zone two formed between the outer periphery of the second-stage conical flow buffer plate and the inner periphery of the collection tank, allow the clear liquid in the upper layer to overflow from this area to the next stage, while the settled solid sludge at the bottom layer is effectively trapped, realizing the directional separation of clear liquid and solid sludge.

[0019] As a further improvement to the above technical solution, the outer peripheral wall of the top of the slow-flow funnel is coaxially and contour-fittingly sealed and fixed to the bottom of the inner peripheral wall of the settling overflow cylinder; the inner cavity of the settling overflow cylinder forms a conical slow-flow plate receiving cavity corresponding to the area above the slow-flow funnel. The settling overflow cylinders are multiple; the multiple settling overflow cylinders can be detachably stacked from top to bottom; the secondary conical flow-delay plate of the upper settling overflow cylinder is embedded in the conical flow-delay plate receiving cavity of the adjacent lower settling overflow cylinder, and the outer peripheral side of the secondary conical flow-delay plate and the inner peripheral side of the corresponding conical flow-delay plate receiving cavity are spaced apart to form an annular overflow zone.

[0020] The beneficial effects of the above technical solution are as follows: By setting multiple sedimentation overflow cylinders that can be detachably stacked from top to bottom, users can flexibly select the number of stacked sedimentation overflow cylinders according to the content and particle size distribution of solid particles in the waste liquid, achieving a dynamic balance between equipment cost and processing capacity while ensuring purification effect; each layer of sedimentation overflow cylinders is detachably stacked, and when the amount of solid slag deposited in a certain layer of slag tank reaches the upper limit, that layer can be disassembled and cleaned separately without overall disassembly, resulting in high maintenance efficiency; at the same time, the secondary conical flow buffer plate of the upper sedimentation overflow cylinder is embedded in the conical flow buffer plate receiving cavity of the adjacent lower sedimentation overflow cylinder, forming an annular overflow zone between the outer and inner circumferences of the two, ensuring that the overflow path of the clear liquid between each level is smooth and orderly, and the step-by-step purification effect is reliable.

[0021] As a further improvement to the above technical solution, a control system is also included. The control system is electrically connected to the lifting mechanism, the liquid supply mechanism and the pneumatic drying mechanism, respectively. The control system is used to control the lifting mechanism to drive the detection end of the probe assembly to switch between the detection station and the cleaning station, and to control the liquid supply mechanism and the pneumatic drying mechanism to clean and dry the detection end of the probe assembly.

[0022] The beneficial effects of the above technical solution are as follows: By setting up a control system that is electrically connected to the lifting mechanism, the liquid supply mechanism, and the pneumatic drying mechanism, the control system coordinates the switching of the lifting mechanism's workstations, the cleaning operation of the liquid supply mechanism, and the air drying operation of the pneumatic drying mechanism, realizing full automation of the "detection, cleaning, drying, and retesting" process without manual intervention, thus significantly reducing labor costs. At the same time, the control system precisely controls the action sequence and operating parameters of each mechanism according to a preset program, eliminating data differences caused by factors such as sampling depth, electrode immersion depth, reading timing, and cleaning cleanliness during manual operation, ensuring high comparability of test data at different times. Furthermore, the control system can support logic programming for periodic retesting, upgrading the pH value detection of slurry from "sampling inspection" to "routine periodic detection," providing continuous and reliable data support for the fine adjustment of the ratio of raw and auxiliary materials in slurry.

[0023] Another aspect of the present invention provides a method for cyclically detecting the pH value of investment casting slurry, employing the aforementioned device for cyclically detecting the pH value of investment casting slurry, comprising the following steps: Step 1: Drive the probe assembly to descend to the detection station through the lifting mechanism, so that the detection end of the probe assembly comes into contact with the slurry to be tested, and perform pH value detection; Step 2: After the test is completed, the probe assembly is driven to rise by the lifting mechanism, so that the detection end returns to the closed cavity and is reset to the cleaning station; Step 3: Inject cleaning fluid into the sealed cavity through the liquid supply mechanism to clean the detection end located at the cleaning station; Step 4: Repeat steps 1 to 3 to achieve cyclical pH detection.

[0024] The pH value cyclic detection method for investment casting slurry provided by this invention uses a lifting mechanism to drive the probe assembly to sequentially perform the steps of descending for detection, rising and resetting to the cleaning station, cleaning inside the sealed cavity, and repeating the cycle. This standardizes the detection process, ensuring that each detection follows the same procedure, eliminating the drawbacks of traditional manual detection where operations vary depending on the person and time, and ensuring consistent operating conditions for each detection. After each detection, the detection end at the cleaning station is immediately cleaned by a liquid supply mechanism, avoiding interference from slurry residues for the next detection. This ensures that each detection accurately reflects the current pH value of the slurry, significantly improving the accuracy and reliability of the data. By repeatedly executing steps one to three, the periodic cyclic detection of the slurry pH value is achieved, giving the pH value data temporal continuity and providing a data foundation for analyzing the evolution trend of slurry performance and controlling the quality of the mold shell.

[0025] As a further improvement to the above technical solution, step three also includes: after the detection end is cleaned, dry gas is delivered into the closed cavity through a pneumatic drying mechanism to air dry the detection end located at the cleaning station.

[0026] The beneficial effects of the above technical solution are as follows: By adding a pneumatic drying step in step three, after the detection end is cleaned, a dry gas is delivered into the closed cavity through a pneumatic drying mechanism to air dry the detection end located at the cleaning station. The air drying process ensures that the surface of the detection end is completely dry, eliminating the problem of cleaning fluid being carried into the slurry to be tested, which would cause slurry dilution and pH value shift, thus ensuring the authenticity of the next test results. The pneumatic drying method has a fast drying speed and can be carried out immediately after cleaning, shortening the testing cycle and increasing the testing frequency. At the same time, for high-viscosity media such as investment casting slurry, liquid film is easily left on the surface of the detection end, which is difficult to completely remove by cleaning alone. Pneumatic drying, as a connecting step between cleaning and the next cycle of testing, effectively solves this industry pain point.

[0027] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a device and method for circulating detection of pH value of investment casting slurry, which has the following advantages and beneficial effects.

[0028] 1. The device of this invention has a high degree of automation, realizing standardized closed-loop detection. By setting up a control system, the lifting mechanism, liquid supply mechanism and pneumatic drying mechanism are coordinated to automatically complete the entire process of detection, cleaning, drying and periodic retesting. This realizes a mode transformation from "manual sampling and detection" to "in-situ automatic cyclic detection", eliminating the data differences caused by factors such as sampling depth, immersion depth, reading timing and cleaning degree in traditional manual operation, and ensuring the high stability and comparability of detection data at different time periods.

[0029] 2. The device of this invention has high detection accuracy and completely solves the problems of probe contamination and residue. By sliding the probe assembly through the through hole in the cleaning chamber and sealing it to form a closed cavity, high-pressure circulating cleaning is achieved under conditions of isolation between the detection end and the outside world. This effectively removes the adhesion and deposition of fine solid particles such as zircon powder and corundum powder in the slurry on the electrode surface, fundamentally avoiding problems such as electrode passivation, micropore blockage, and reference potential shift. Combined with the rapid air drying treatment of the pneumatic drying mechanism, the interference of water residue on pH detection value is completely eliminated, significantly improving the accuracy, repeatability, and response speed of the detection data.

[0030] 3. The device of this invention is green and environmentally friendly, realizing closed-loop treatment and resource recycling of waste liquid. By setting up a three-stage gravity sedimentation structure in which the sedimentation overflow cover, sedimentation overflow cylinder and liquid collection tank are connected from top to bottom, the waste liquid containing solid particles generated during cleaning is purified step by step. This realizes the recycling and reuse of clean water and the centralized collection of solid waste residue, eliminating the environmental pollution caused by the direct discharge of waste liquid and waste residue containing heavy metal oxide powder, and meeting the green production requirements of modern foundry industry.

[0031] 4. The device of this invention has a compact structure, strong adaptability, and wide range of applications. By integrating the lifting mechanism, probe assembly, cleaning mechanism, pneumatic drying mechanism, and waste liquid recovery and purification assembly into one unit, the structure is compact and easy to integrate with existing investment casting production lines. At the same time, the detection cycle, cleaning time, drying time, and other parameters can be customized through the control system, and can be flexibly adjusted according to different slurry characteristics, adapting to various high-viscosity slurries and viscous liquid pH value cyclic detection scenarios.

[0032] 5. The device of this invention extends the service life of the electrode and reduces maintenance costs. By performing closed-loop high-pressure cleaning and pneumatic drying on the detection end immediately after testing, the slurry is prevented from drying and coating on the electrode surface, significantly reducing chemical corrosion and mechanical wear of the electrode, thus significantly extending the service life of the pH electrode and reducing the frequency of consumable replacement and overall maintenance costs.

[0033] In summary, this invention effectively overcomes many technical challenges of existing offline pH value detection for investment casting slurries, such as cumbersome operation, large human error, easy probe clogging, data drift and distortion, lack of standardized procedures, and direct discharge of waste liquid causing pollution. It realizes refined, standardized, and green cyclical detection and control of slurry pH value, which has important practical application value for improving shell quality and the yield of precision castings. Attached Figure Description

[0034] 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the overall structure of a pH value circulation detection device for investment casting slurry according to the present invention.

[0036] Figure 2 This is an axial cross-sectional view of the cleaning chamber and probe assembly of the pH value circulation detection device for investment casting slurry of the present invention.

[0037] Figure 3 This is a schematic diagram of the lifting mechanism, probe assembly, and cleaning mechanism of the pH value circulation detection device for investment casting slurry of the present invention, installed on the lifting mechanism mounting frame.

[0038] Figure 4 This is a schematic diagram of the cleaning chamber structure of a pH value circulation detection device for investment casting slurry according to the present invention.

[0039] Figure 5 This is a schematic diagram of the protective tube portion of a pH value circulation detection device for investment casting slurry according to the present invention.

[0040] Figure 6 This is a schematic diagram of the probe structure of a pH value circulation detection device for investment casting slurry according to the present invention.

[0041] Figure 7 This is a schematic diagram of the lifting mechanism mounting frame structure of the pH value circulation detection device for investment casting slurry according to the present invention.

[0042] Figure 8 This is a schematic diagram of the lifting mechanism of a pH value circulation detection device for investment casting slurry according to the present invention.

[0043] Figure 9 This is a schematic diagram of the waste liquid recovery and purification component of a pH value circulation detection device for investment casting slurry according to the present invention.

[0044] Figure 10 This is an axial cross-sectional view of the waste liquid recovery and purification component of the pH value circulation detection device for investment casting slurry of the present invention.

[0045] Figure 11 This is a schematic diagram of the sedimentation overflow cylinder structure of a pH value circulation detection device for investment casting slurry according to the present invention.

[0046] In the diagram: 1. Frame; 11. Main frame; 12. Lifting mechanism mounting frame; 2. Lifting mechanism; 21. Electric lifting slide; 22. Lifting motor; 3. Probe assembly; 31. Probe; 311. Detection end; 32. Protective tube; 321. Liquid inlet window; 322. Sealing ring; 4. Cleaning mechanism; 41. Cleaning chamber; 411. Through hole; 412. Liquid inlet; 413. Liquid return port; 414. Sealing ring; 42. Liquid supply mechanism; 421. Liquid inlet pipe; 422. Liquid return pipe; 5. Waste liquid recovery and purification assembly; 51. Settling overflow cover; 511. Waste liquid inlet; 512. First-stage conical slow flow... Plate; 5121, Primary slag collection tank; 513, Annular overflow zone one; 514, Vent; 52, Settling overflow cylinder; 521, Slow-flow funnel; 522, Secondary conical slow-flow plate; 5221, Secondary slag collection tank; 523, Annular overflow zone two; 524, Conical slow-flow plate receiving cavity; 525, Annular overflow zone three; 53, Liquid collection tank; 531, Clean liquid outlet; 54, Support pole; 55, Groove; 56, Column; 6, Slurry tank; 7, Programmable control cabinet; 71, Operation panel; 72, Real-time digital display; 73, Status indicator light; 74, Emergency stop button; 75, Signal transmission line; 8, Mounting frame. Detailed Implementation

[0047] 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.

[0048] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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 invention.

[0049] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0050] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0051] The existing methods for pH value detection of ceramic slurries in investment casting generally employ offline sampling, which presents numerous technical challenges, including electrode coating by high-viscosity slurry, probe clogging by solid powder, slow electrode response, data drift and distortion, poor repeatability, and large human error. Furthermore, offline sampling introduces secondary errors due to changes in slurry conditions and dilution pretreatment, making it impossible to accurately reflect the true pH value of the slurry under production conditions in real time. This hinders precise and routine pH control of the slurry, leading to poor slurry stability, uneven shell coating quality, and defects such as sand adhesion, peeling, and cracking in castings. Moreover, traditional detection methods lack supporting cleaning, drying, and waste liquid treatment structures, resulting in low detection efficiency, rapid equipment wear, and insufficient environmental friendliness. Therefore, this invention aims to provide a circulating pH value detection device and method for investment casting slurries.

[0052] The purpose of this invention is to overcome the inherent defects of traditional offline testing, abandoning the outdated methods of manual sampling, manual testing, and manual cleaning, and achieving in-situ, real-time, and periodic cyclical monitoring of the pH value of investment casting slurry. By incorporating an automatic probe cleaning structure and a pneumatic drying mechanism, the viscous slurry adhering to the probe surface is thoroughly removed, eliminating detection errors caused by media coating and probe blockage, ensuring accurate and repeatable data for each test. Through a programmed cyclical testing logic, unattended continuous monitoring is achieved, stabilizing slurry process parameters. Simultaneously, a waste liquid sedimentation, multi-stage filtration, and waste residue collection and treatment system is provided to achieve the recycling and reuse of testing waste liquid and compliant treatment of solid residue, solving the problems of traditional testing lacking environmental protection treatment, resource waste, and environmental pollution. Ultimately, this achieves refined, standardized, and green control of the pH parameter of investment casting slurry, stabilizing slurry coating performance, and significantly improving shell quality and the yield of precision castings.

[0053] According to embodiments of the present invention, such as Figures 1 to 11As shown, a pH value circulation detection device for investment casting slurry includes: a frame 1, a lifting mechanism 2, a probe assembly 3, and a cleaning mechanism 4.

[0054] The lifting mechanism 2 is mounted on the frame 1; the probe assembly 3 is mounted on the lifting end of the lifting mechanism 2.

[0055] The cleaning mechanism 4 includes a cleaning chamber 41 and a liquid supply mechanism 42. The cleaning chamber 41 is mounted on the frame 1 and has a through hole 411 on its top surface. The probe assembly 3 can slide through the through hole 411 and seal its top and bottom openings. At the same time, the detection end 311 of the probe assembly 3 is located in the closed cavity of the through hole 411. The cleaning pipeline of the liquid supply mechanism 42 is circulated in the closed cavity to supply cleaning liquid to clean the detection end 311 of the probe assembly 3 located in the closed cavity. The lifting mechanism 2 can drive the detection end 311 of the probe assembly 3 to descend to the detection position below the cleaning chamber 41 for pH value detection.

[0056] In this embodiment, by setting a cleaning cavity 41 with a through hole 411, the probe assembly 3 can slide through the through hole 411 and block its top and bottom openings, forming a closed cavity inside the through hole 411. The cleaning pipeline of the liquid supply mechanism 42 is circulated with the closed cavity, realizing in-situ closed cleaning of the detection end of the probe 31. This structure effectively removes slurry residue and solid particles adhering to the electrode surface, avoiding electrode passivation and data distortion caused by incomplete wiping and micropore blockage in existing offline testing. Simultaneously, the lifting mechanism 2 drives the probe assembly 3 to automatically switch between the testing station and the closed cavity, realizing a closed-loop process for testing and cleaning. This eliminates the need for traditional non-standardized operations such as manual sampling, wiping, calibration, and cleaning, and removes the drawback of poor comparability of test data from different operators and at different times. Furthermore, after testing, the probe 31 immediately enters the closed cavity for cleaning, preventing slurry from drying and coating the electrode surface. This eliminates the need for frequent manual wiping and calibration, significantly reducing electrode wear and extending electrode lifespan. The cleaning chamber 41 integrates a through-hole 411 and a closed cavity, with the liquid supply mechanism 42 connected via a pipeline. The compact structure facilitates integration with existing investment casting production lines and is suitable for industrial continuous production scenarios.

[0057] In some embodiments, the probe assembly 3 includes a probe 31 and a protective tube 32; the lower end of the protective tube 32 is closed, the lower end of the probe 31 is a detection end 311 and is coaxially and sealed through the protective tube 32, and a liquid inlet cavity is formed in the protective tube 32 corresponding to the outer periphery of the detection end 311; a liquid inlet window 321 communicating with the liquid inlet cavity is opened on the outer peripheral wall of the protective tube 32 corresponding to the liquid inlet cavity; the protective tube 32 can slide through the through hole 411 and block its top and bottom openings, while the liquid inlet cavity communicates with the closed cavity of the through hole 411 through the liquid inlet window 321; the upper part of the protective tube 32 is installed on the lifting end of the lifting mechanism 2.

[0058] By installing a protective tube 32 with a closed lower end outside the probe 31, and an inlet window 321 on the outer peripheral wall of the protective tube 32, an inlet chamber is formed on the outer periphery of the detection end 311 of the probe 31, communicating with the closed cavity. During detection, the slurry enters the inlet chamber through the inlet window 321 and contacts the detection end. During cleaning, the cleaning fluid enters the inlet chamber through the closed cavity and the inlet window 321 to flush the detection end. Detection and cleaning are completed in the same station, without the probe 31 needing to detach from the protective tube 32, resulting in a simple and efficient structure. Simultaneously, the protective tube 32 encloses the detection end of the probe 31, allowing it to contact the external medium only at the inlet window 321. This prevents the probe 31 from colliding with the slurry tank 6 wall, cleaning chamber 41, etc., during lifting, moving, and station switching, improving the operational safety of the probe 31. Furthermore, the inlet window 321, as the only connecting channel between the inlet chamber and the closed cavity, guides the slurry and cleaning fluid to flow steadily into the surface of the detection end during detection and cleaning, ensuring a clear fluid path and guaranteeing the stability of the detection and cleaning effects.

[0059] In some embodiments, the probe 31 is a cylindrical glass electrode at the bottom; the probe 31 is coaxially and sealed in the protective tube 32, and a sealing ring 322 is embedded in the inner peripheral wall of the protective tube 32 at the lower part of the probe 31 to seal it, so as to prevent liquid from flowing back from the liquid inlet chamber to the gap between the protective tube 32 and the probe 31.

[0060] In some embodiments, sealing rings 414 are fitted into the inner peripheral wall of the through hole 411 near its top and bottom openings to improve the sealing performance of the outer peripheral wall of the protective tube 32 to the top and bottom openings of the through hole 411. Sealing rings 414 can also be fitted into the inner peripheral wall of the through hole 411 near the closed cavity to further improve the sealing performance.

[0061] In some embodiments, the lifting mechanism 2 includes an electric lifting slide 21 and a lifting motor 22. The control system is electrically connected to the lifting motor for drive control. The upper part of the protective tube 32 is fixedly installed on the lifting end of the electric lifting slide, and a probe protective sleeve is fitted on the outer periphery of the upper part of the protective tube 32 to form a smooth and continuous cylindrical surface on the outer periphery of the protective tube 32. The lifting motor provides power to the electric lifting slide, driving the probe assembly 3 to move precisely in the vertical direction, completing the switching between the detection station and the cleaning station. During detection, the lifting mechanism 2 drives the probe assembly 3 to descend, so that the liquid inlet window 321 at the lower end of the protective tube 32 passes through the bottom opening of the through hole 411 of the cleaning chamber 41, and the detection end of the probe 31 extends below the surface of the slurry to be tested for pH value detection; after the detection is completed, the lifting mechanism 2 drives the probe assembly 3 to rise and reset, so that the protective tube 32 slides through the through hole 411 and seals its top and bottom openings, and the detection end of the probe 31 returns to the closed cavity, resetting to the cleaning station. The entire process is characterized by precise positioning and stable operation, ensuring the accuracy of the test data while preventing the probe 31 from being damaged by collisions with the slurry tank wall or the cleaning chamber 41 during movement.

[0062] In some embodiments, a pneumatic drying mechanism is also included, wherein the air supply line of the pneumatic drying mechanism is connected to a closed cavity for supplying drying gas into the closed cavity to dry the detection end of the probe 31.

[0063] If the cleaning solution remaining on the surface of the detection end after cleaning is carried into the slurry to be tested, it will dilute the slurry and change the local pH value, leading to distortion of the data in the next test. The pneumatic drying mechanism quickly dries the detection end by delivering high-pressure gas into the closed cavity, eliminating the interference of water residue on the detection accuracy at the source. Compared with natural air drying or manual wiping, the pneumatic drying method can complete the drying in a few seconds, which significantly shortens the waiting time between two tests and provides time guarantee for high-frequency, periodic cyclic testing. In addition, the drying process ensures that the detection end of the probe 31 is in a clean and dry initial state before each test, ensuring that the starting conditions of each test are consistent and significantly improving the repeatability and comparability of periodic retest data. At the same time, for high-viscosity media such as investment casting slurry, cleaning alone is not enough to completely remove the liquid film remaining on the surface of the detection end. Pneumatic drying, as a connecting step between cleaning and the next cycle of testing, effectively solves this industry pain point.

[0064] In some embodiments, there are multiple liquid inlet windows 321; the multiple liquid inlet windows 321 are arranged at intervals along the circumference of the protective tube 32; the outer peripheral wall of the cleaning chamber 41 is provided with a liquid inlet 412 and a liquid return port 413 corresponding to the closed cavity; the liquid inlet 412 and the liquid return port 413 are arranged at intervals along the circumference of the cleaning chamber 41 and correspond one-to-one with two liquid inlet windows 321. The liquid supply mechanism 42 includes an inlet pipe 421, a return pipe 422, a circulation pump, and a waste liquid recovery and purification component 5. One end of the inlet pipe 421 is connected to the inlet port 412, and the other end is connected to the clean liquid outlet 531 of the waste liquid recovery and purification component 5. One end of the return pipe 422 is connected to the return port 413, and the other end is connected to the waste liquid inlet 511 of the waste liquid recovery and purification component 5. The circulation pump is installed on the inlet pipe 421 and is used to circulate the cleaning liquid into the closed cavity and the inlet cavity to clean the detection end.

[0065] By setting multiple circumferentially spaced inlet windows 321 and corresponding inlet ports 412 and return ports 413 on the outer peripheral wall of the cleaning chamber 41, the cleaning fluid can enter the closed cavity from the inlet port 412 and pass through the inlet windows 321 from different circumferential directions into the inlet cavity, forming a multi-angle and all-round flushing of the detection end, eliminating cleaning dead corners; at the same time, the cleaning fluid is driven by a circulation pump to circulate between the closed cavity, the inlet cavity, and the waste liquid recovery and purification component 5, realizing the repeated use of the cleaning fluid and reducing the consumption of pure water; and the waste liquid recovery and purification component 5 centrally collects and purifies the waste liquid after cleaning, avoiding the environmental pollution caused by the direct discharge of waste liquid containing solid particles such as zircon powder and corundum powder, and meeting the requirements of green industrial production.

[0066] In some embodiments, the waste liquid recovery and purification assembly includes a sedimentation overflow cover 51, a sedimentation overflow cylinder 52, and a collection tank 53; the sedimentation overflow cover 51, the sedimentation overflow cylinder 52, and the collection tank 53 are connected in sequence from top to bottom; a waste liquid inlet 511 is provided at the middle of the top of the sedimentation overflow cover 51; and a clean liquid outlet 531 is provided at the bottom of the collection tank 53.

[0067] This invention employs a three-stage structure consisting of a sedimentation overflow cover 51, a sedimentation overflow cylinder 52, and a collection tank 53 connected sequentially from top to bottom. Utilizing the density difference between solid particles and liquid in the waste liquid, natural solid-liquid separation is achieved through three vertically connected sedimentation spaces. This eliminates the need for additional centrifugal or filtration power equipment, resulting in a simple structure and low operating costs. Solid impurities in the waste liquid are deposited step by step within each sedimentation space, and the supernatant overflows into the next stage, ultimately yielding reusable purified water at the bottom of the collection tank 53, thus realizing the recycling and reuse of water resources.

[0068] Specifically, the top of the settling overflow cover 51 is provided with an exhaust port 514.

[0069] In some embodiments, a primary conical flow buffer plate 512 is fixed inside the sedimentation overflow cover 51 below the waste liquid inlet 511 by a support rod; the outer periphery of the primary conical flow buffer plate 512 is bent upward to form a primary sludge trough 5121; the outer periphery of the primary conical flow buffer plate 512 and the inner periphery of the corresponding sedimentation overflow cover 51 are spaced apart to form an annular overflow zone 513. The bottom of the settling overflow cover 51 is detachably connected to the top of the settling overflow cylinder 52; a slow-flow funnel 521 is fixed to the inner circumferential wall of the settling overflow cylinder 52; the upper port of the slow-flow funnel 521 corresponds to the lower part of the annular overflow zone 513 to collect overflow liquid; a secondary conical slow-flow plate 522 is fixed below the slow-flow funnel 521 by a support rod 54, and the outer circumferential side of the secondary conical slow-flow plate 522 is bent upward to form a secondary sludge accumulation trough 5221; the outer circumferential part of the settling overflow cylinder 52 is detachably connected to the top of the liquid collection tank 53; the secondary conical slow-flow plate 522 is embedded inside the liquid collection tank 53; the outer circumferential side of the secondary conical slow-flow plate 522 and the inner circumferential side of the corresponding liquid collection tank 53 are spaced apart to form an annular overflow zone 523.

[0070] By setting a primary conical flow buffer 512 and a secondary conical flow buffer 522 respectively, the conical flow buffers buffer, slow down, and disperse the downward flow of waste liquid, significantly reducing the waste liquid velocity and providing sufficient settling time for solid particles, thus avoiding the problem of particles being entrained in the overflow liquid due to excessive flow velocity. The primary slag collection trough 5121 formed by the upward bending of the outer periphery of the primary conical flow buffer 512 and the secondary slag collection trough 5221 formed by the upward bending of the outer periphery of the secondary conical flow buffer 522 can retain the deposited solid particles. Inside the tank, even if subsequent waste liquid continues to flow in, the settled particles will not be stirred up again due to the disturbance of the liquid flow, ensuring the continuous stability of solid-liquid separation. At the same time, the annular overflow zone 513 formed between the outer periphery of the first-stage conical flow buffer 512 and the inner periphery of the settling overflow cover 51, and the annular overflow zone 523 formed between the outer periphery of the second-stage conical flow buffer 522 and the inner periphery of the collection tank 53, allow the clear liquid in the upper layer to overflow from this area to the next stage, while the settled solid sludge at the bottom layer is effectively intercepted, realizing the directional separation of clear liquid and solid sludge.

[0071] In some embodiments, the top outer peripheral wall of the slow-flow funnel 521 is coaxially and contour-fittedly sealed and fixed to the bottom of the inner peripheral wall of the settling overflow cylinder 52; a conical slow-flow plate receiving cavity 524 is formed in the inner cavity of the settling overflow cylinder 52 corresponding to the area above the slow-flow funnel 521. There are multiple settling overflow cylinders 52; the multiple settling overflow cylinders 52 can be detachably stacked from top to bottom; the secondary conical flow buffer plate 522 of the upper settling overflow cylinder 52 is embedded in the conical flow buffer plate receiving cavity 524 of the adjacent lower settling overflow cylinder 52, and the outer peripheral side of the secondary conical flow buffer plate 522 and the inner peripheral side of the corresponding conical flow buffer plate receiving cavity 524 are spaced apart to form an annular overflow zone 3 525.

[0072] By setting multiple sedimentation overflow cylinders 52 that can be detachably stacked from top to bottom, users can flexibly select the number of stacked sedimentation overflow cylinders 52 according to the content and particle size distribution of solid particles in the waste liquid, achieving a dynamic balance between equipment cost and processing capacity while ensuring purification effect. Each layer of sedimentation overflow cylinders 52 is detachably stacked, and when the amount of solid slag deposited in a certain layer of slag tank reaches the upper limit, that layer can be disassembled and cleaned separately without overall disassembly, resulting in high maintenance efficiency. At the same time, the secondary conical flow buffer plate 522 of the upper sedimentation overflow cylinder 52 is embedded in the conical flow buffer plate receiving cavity 524 of the adjacent lower sedimentation overflow cylinder 52, forming an annular overflow zone 3 525 between the outer and inner circumferences of the two, ensuring a smooth and orderly overflow path of the clear liquid between each level, and reliable step-by-step purification effect.

[0073] Specifically, the settling overflow cover 51, the settling overflow cylinder 52, and the collection tank 53 are all circular; the settling overflow cover 51 and the settling overflow cylinder 52, any two adjacent settling overflow cylinders 52, and the collection tank 53 and the corresponding settling overflow cylinder 52 are all detachably connected by a locking groove 55 and a locking post 56 structure provided on them.

[0074] In some embodiments, the pneumatic drying mechanism includes an air source and an air supply pipeline. The air outlet of the air source is connected to one end of the air supply pipeline, and the other end of the air supply pipeline is connected to the liquid inlet 412. The air source can be a compressed air source, which provides a high-pressure airflow for pneumatic drying and auxiliary venting. A three-way pipe is installed at the liquid inlet 412. The first port of the three-way pipe is connected to the liquid inlet 412, the second port is connected to the other end of the air supply pipeline, and the third port is connected to one end of the liquid inlet pipe 421. The liquid inlet pipe 421 is equipped with a liquid inlet valve, the liquid return pipe 422 is equipped with a liquid return valve, and an air supply valve is installed on the air supply pipeline. When the inlet valve is closed and the return valve is open, the cleaning liquid in the inlet chamber and the closed cavity flows back to the waste liquid recovery and purification component 5 under gravity through the return port 413 and the return pipe 422. When it is necessary to assist in emptying the residual cleaning liquid, the air supply valve is opened, and compressed air enters the closed cavity through the air supply pipeline, the three-way pipe, and the inlet 412 to force out the residual cleaning liquid, thereby shortening the emptying time. After the residual cleaning liquid is emptied, the inlet valve is kept closed, the return valve is opened, and the air supply valve is opened. Compressed air continues to enter the closed cavity to air dry the detection end of the probe 31 located at the cleaning station. The airflow carries moisture and is discharged through the return port 413, the return pipe 422, and the waste liquid recovery and purification component 5. After the air drying is completed, the air supply valve is closed.

[0075] In some embodiments, a control system is also included. The control system is electrically connected to the lifting mechanism 2, the liquid supply mechanism 42 and the pneumatic drying mechanism, respectively. The control system is used to control the lifting mechanism 2 to drive the detection end of the probe assembly 3 to switch between the detection station and the cleaning station, and to control the liquid supply mechanism 42 and the pneumatic drying mechanism to clean and dry the detection end of the probe assembly 3.

[0076] By setting up a control system that is electrically connected to the lifting mechanism 2, the liquid supply mechanism 42, and the pneumatic drying mechanism, the control system coordinates the switching of the lifting mechanism 2, the cleaning operation of the liquid supply mechanism 42, and the air drying operation of the pneumatic drying mechanism, realizing the full automation of the "detection, cleaning, drying, and retesting" process without manual intervention, which significantly reduces labor costs. At the same time, the control system precisely controls the action sequence and operating parameters of each mechanism according to the preset program, eliminating data differences caused by factors such as sampling depth, electrode immersion depth, reading timing, and cleaning cleanliness in manual operation, ensuring the high comparability of detection data at different times. Furthermore, the control system can support the logic programming of periodic retesting, upgrading the pH value detection of slurry from "sampling inspection" to "routine periodic detection", providing continuous and reliable data support for the fine adjustment of the ratio of raw and auxiliary materials in slurry.

[0077] Specifically, the control system is electrically connected to the probe 31 of the probe assembly 3 via the signal transmission line 75, and is used to collect pH detection signals and process, record and display the detection data.

[0078] Specifically, the control system has a program control module, which is the central hub of the device. It has a built-in editable periodic detection program that supports custom parameters such as detection cycle, cleaning time, drying time, and liquid immersion detection depth. It can automatically coordinate the orderly start-up and shutdown of various mechanisms and their coordinated operation. It also has functions such as real-time detection, data storage, fault alarm, and operation status monitoring.

[0079] Specifically, the program control module is integrated into the program control cabinet 7, which is fixedly mounted on the mounting bracket 8. The panel of the program control cabinet 7 includes an operation panel 71, a real-time digital display 72, status indicator lights 73, and an emergency stop button 74. Operators input or modify process parameters such as detection cycle, cleaning time, drying time, and liquid immersion depth into the program control module via the operation panel 71. The real-time digital display 72 displays the current pH detection value locally. The status indicator lights 73 display the current operating status of the device and issue audible and visual alarm signals in case of abnormalities. The emergency stop button 74 immediately interrupts the operation of all mechanisms in an emergency. The probe 31 of the probe assembly 3 is electrically connected to the program control module via a signal transmission line 75. The program control module acquires the pH detection signal from the probe 31 via the signal transmission line 75 and processes, records, and stores the detection data.

[0080] In some embodiments, the frame 1 includes a main frame 11 and a lifting mechanism mounting frame 12; the lifting mechanism mounting frame 12 is fixed to the upper part of the main frame 11; the fixed end of the electric lifting slide and the lifting motor are both mounted on the lifting mechanism mounting frame 12; the cleaning chamber 41 is installed at the bottom of the lifting mechanism mounting frame 12 and corresponds to the lower part of the electric lifting slide.

[0081] Another embodiment of the present invention provides a method for cyclically detecting the pH value of investment casting slurry, employing an investment casting slurry pH value cyclic detection device, comprising the following steps: Step 1: Drive the probe assembly 3 to the detection station through the lifting mechanism 2, so that the detection end of the probe assembly 3 comes into contact with the slurry to be tested, and perform pH value detection; Step 2: After the test is completed, the probe assembly 3 is driven to rise by the lifting mechanism 2, so that the test end returns to the closed cavity and is reset to the cleaning station; Step 3: Inject cleaning fluid into the closed cavity through the liquid supply mechanism 42 to clean the detection end located at the cleaning station; Step 4: Repeat steps 1 to 3 to achieve cyclical pH detection.

[0082] The pH value cyclic detection method for investment casting slurry provided in this embodiment uses a lifting mechanism 2 to drive the probe assembly 3 to sequentially perform the steps of descending for detection, rising and resetting to the cleaning station, cleaning inside the sealed cavity, and repeating the cycle. This standardizes the detection process, ensuring that each detection follows the same procedure, eliminating the drawbacks of traditional manual detection where operations vary from person to person and time to time, and ensuring consistent operating conditions for each detection. After each detection, the detection end located at the cleaning station is immediately cleaned by the liquid supply mechanism 42, avoiding interference from slurry residues for the next detection. This ensures that each detection accurately reflects the current pH value of the slurry, significantly improving the accuracy and reliability of the data. By repeatedly executing steps one to three, the periodic cyclic detection of the slurry pH value is achieved, giving the pH value data temporal continuity and providing a data foundation for analyzing the evolution trend of slurry performance and controlling the quality of the mold shell.

[0083] In some embodiments, step three further includes: after the detection end is cleaned, dry gas is delivered into the closed cavity through a pneumatic drying mechanism to air dry the detection end located at the cleaning station.

[0084] By adding a pneumatic drying step in step three, after the detection end is cleaned, a pneumatic drying mechanism delivers drying gas into the sealed cavity to air-dry the detection end located at the cleaning station. This air-drying process ensures that the surface of the detection end is completely dry, preventing the cleaning fluid from being carried into the slurry to be tested, which would cause slurry dilution and pH value shift, thus ensuring the authenticity of the next test results. The pneumatic drying method is fast and can be performed immediately after cleaning, shortening the testing cycle and increasing the testing frequency. At the same time, for high-viscosity media such as investment casting slurry, liquid film is easily left on the surface of the detection end, which is difficult to completely remove by cleaning alone. Pneumatic drying, as a connecting step between cleaning and the next cycle of testing, effectively solves this industry pain point.

[0085] In some embodiments, the overall operation of the device is executed automatically and periodically according to the following steps: S1: Detection Trigger - The program control module automatically triggers the detection command according to the preset cycle (or is manually triggered by the operator through the operation panel). S2: Drainage preparation - The control system opens the return valve (corresponding drain valve) to discharge the residual cleaning liquid in the closed cavity and the inlet cavity into the waste liquid recovery and purification component 5. S3: Pneumatic drying - The control system opens the air supply valve, and the pneumatic drying mechanism delivers compressed air into the closed cavity to dry the residual moisture at the detection end of probe 31 and the inner wall of the closed cavity. S4: Descent Detection - The control system controls the lifting mechanism 2 to drive the probe assembly 3 to descend, so that the detection end of the probe 31 extends below the surface of the slurry to be tested for pH value detection. S5: Data Recording - The control system acquires pH detection signals in real time through signal transmission line 75, and records and stores the current pH value after the reading stabilizes. S6: Reset Cleaning - After the test is completed, the control system controls the lifting mechanism 2 to drive the probe assembly 3 to rise and reset to the cleaning position, so that the protective tube 32 slides into the through hole 411 and seals its top and bottom openings. S7: High-pressure flushing - The control system opens the inlet valve and starts the circulation pump. The liquid supply mechanism 42 injects the cleaning liquid into the closed cavity and the inlet cavity through the inlet pipe 421, the three-way pipe and the inlet port 412 to perform high-pressure circulation flushing on the detection end of the probe 31. S8: Draining and Drying - After rinsing, the control system shuts off the circulation pump and the inlet valve, opens the return valve to drain the cleaning fluid, and then opens the air supply valve. The pneumatic drying mechanism delivers compressed air into the closed cavity to dry the detection end. S9: Immersion and standby - After drying is completed, the control system closes the gas supply valve and the liquid return valve, opens the liquid inlet valve and starts the circulation pump to inject pure water into the closed cavity, so that the detection end of the probe 31 is immersed in pure water and standsby. S10: Periodic retest - After the next preset testing period arrives, it will automatically jump to S1 and repeat the above steps without any manual intervention.

[0086] Specifically, in S9: Immersion and Standby – After drying, the control system closes the air supply valve, opens the liquid inlet valve, and starts the circulation pump. Pure water is injected into the closed cavity and liquid inlet chamber through the liquid inlet pipe 421, the three-way pipe, and the liquid inlet 412, so that the detection end of the probe 31 is completely immersed in pure water and ready for use. A clean liquid and pure water switching valve is installed on the section of the pipe between its inlet end and the circulation pump on the liquid inlet pipe 421. The clean liquid and pure water switching valve is a two-inlet, one-outlet electrically controlled valve. One inlet is connected to the clean liquid outlet 531 (cleaning liquid supply) of the waste liquid recovery and purification component 5, and the other inlet is connected to the pure water supply pipeline. The outlet is connected to the liquid inlet pipe 421. The pure water comes from an external pure water supply system or an independently set pure water storage tank. The outlet of the pure water storage tank is connected to the pure water inlet of the clean liquid and pure water switching valve through a pure water pipeline. By controlling the switching valve between clean liquid and pure water, the supply of cleaning liquid is turned off and the supply of pure water is turned on. The circulating pump sends pure water into the closed cavity through the inlet pipe 421.

[0087] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0088] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A device for circulating and detecting the pH value of investment casting slurry, characterized in that, include: Rack (1); A lifting mechanism (2) is installed on the frame (1); The probe assembly (3) is installed at the lifting end of the lifting mechanism (2); The cleaning mechanism (4) includes a cleaning chamber (41) and a liquid supply mechanism (42); the cleaning chamber (41) is mounted on the frame (1) and has a through hole (411) on its top surface; the probe assembly (3) can slide through the through hole (411) and block its top and bottom openings, while the detection end of the probe assembly (3) is located in the closed cavity of the through hole (411); the cleaning pipeline of the liquid supply mechanism (42) is circulated in the closed cavity to supply cleaning liquid to clean the detection end of the probe assembly (3) located in the closed cavity; the lifting mechanism (2) can drive the detection end of the probe assembly (3) to descend to the detection position below the cleaning chamber (41) for pH value detection.

2. The pH value circulation detection device for investment casting slurry according to claim 1, characterized in that, The probe assembly (3) includes a probe (31) and a protective tube (32); the lower end of the protective tube (32) is closed, the lower end of the probe (31) is the detection end and is coaxially sealed in the protective tube (32), and a liquid inlet cavity is formed in the protective tube (32) corresponding to the outer periphery of the detection end; the outer peripheral wall of the protective tube (32) is provided with a liquid inlet window (321) connecting the liquid inlet cavity; the protective tube (32) can slide into the through hole (411) and block its top and bottom openings, while the liquid inlet cavity is connected to the closed cavity of the through hole (411) through the liquid inlet window (321); the upper part of the protective tube (32) is installed on the lifting end of the lifting mechanism (2).

3. The pH value circulation detection device for investment casting slurry according to claim 2, characterized in that, It also includes a pneumatic drying mechanism, the air supply line of which is connected to the closed cavity, for supplying drying gas into the closed cavity to dry the detection end of the probe (31).

4. The pH value circulation detection device for investment casting slurry according to claim 3, characterized in that, There are multiple liquid inlet windows (321); the multiple liquid inlet windows (321) are arranged at intervals along the circumference of the protective tube (32); the outer peripheral wall of the cleaning chamber (41) is provided with a liquid inlet (412) and a liquid return port (413) corresponding to the closed cavity; the liquid inlet (412) and the liquid return port (413) are arranged at intervals along the circumference of the cleaning chamber (41) and correspond one-to-one with two liquid inlet windows (321). The liquid supply mechanism (42) includes an inlet pipe (421), a return pipe (422), a circulation pump, and a waste liquid recovery and purification component (5); one end of the inlet pipe (421) is connected to the inlet port (412), and the other end is connected to the clean liquid outlet (531) of the waste liquid recovery and purification component (5); one end of the return pipe (422) is connected to the return port (413), and the other end is connected to the waste liquid inlet (511) of the waste liquid recovery and purification component (5); the circulation pump is installed on the inlet pipe (421) and is used to circulate the cleaning liquid into the closed cavity and the inlet cavity to clean the detection end.

5. The pH value circulation detection device for investment casting slurry according to claim 4, characterized in that, The waste liquid recycling and purification assembly includes a sedimentation overflow cover (51), a sedimentation overflow cylinder (52), and a collection tank (53); the sedimentation overflow cover (51), the sedimentation overflow cylinder (52), and the collection tank (53) are connected in sequence from top to bottom; the sedimentation overflow cover (51) has a waste liquid inlet (511) at the top center; the collection tank (53) has a clean liquid outlet (531) at the bottom.

6. The pH value circulation detection device for investment casting slurry according to claim 5, characterized in that, The sedimentation overflow cover (51) has a first-stage conical flow buffer plate (512) located inside the waste liquid inlet (511) below it; the outer periphery of the first-stage conical flow buffer plate (512) is bent upward to form a first-stage sludge trough (5121); the outer periphery of the first-stage conical flow buffer plate (512) and the inner periphery of the corresponding sedimentation overflow cover (51) are spaced apart to form an annular overflow zone (513). The bottom of the settling overflow cover (51) is detachably connected to the top of the settling overflow cylinder (52); a slow-flow funnel (521) is fixed on the inner circumferential wall of the settling overflow cylinder (52); the upper port of the slow-flow funnel (521) corresponds to the lower part of the first annular overflow zone (513) to collect overflow liquid; a secondary conical slow-flow plate (522) is provided below the slow-flow funnel (521), and the outer circumferential side of the secondary conical slow-flow plate (522) is bent upward to form a secondary sludge trough (5221); the outer circumferential part of the settling overflow cylinder (52) is detachably connected to the top of the liquid collection tank (53); the secondary conical slow-flow plate (522) is embedded in the inside of the liquid collection tank (53); the outer circumferential side of the secondary conical slow-flow plate (522) and the corresponding inner circumferential side of the liquid collection tank (53) are spaced apart to form a second annular overflow zone (523).

7. The pH value circulation detection device for investment casting slurry according to claim 6, characterized in that, The outer peripheral wall of the top of the slow-flow funnel (521) is coaxial and contour-fittedly sealed and fixed to the bottom of the inner peripheral wall of the settling overflow cylinder (52); the inner cavity of the settling overflow cylinder (52) forms a conical slow-flow plate receiving cavity (524) corresponding to the area above the slow-flow funnel (521). There are multiple settling overflow cylinders (52); the multiple settling overflow cylinders (52) can be detachably stacked from top to bottom; the secondary conical flow buffer plate (522) of the upper settling overflow cylinder (52) is embedded in the conical flow buffer plate receiving cavity (524) of the adjacent lower settling overflow cylinder (52), and the outer peripheral side of the secondary conical flow buffer plate (522) and the inner peripheral side of the corresponding conical flow buffer plate receiving cavity (524) are spaced apart to form an annular overflow zone three (525).

8. The pH value circulation detection device for investment casting slurry according to claim 7, characterized in that, It also includes a control system, which is electrically connected to the lifting mechanism (2), the liquid supply mechanism (42) and the pneumatic drying mechanism respectively. The control system is used to control the lifting mechanism (2) to drive the detection end of the probe assembly (3) to switch between the detection station and the cleaning station, and to control the liquid supply mechanism (42) and the pneumatic drying mechanism to clean and dry the detection end of the probe assembly (3).

9. A method for cyclically detecting the pH value of investment casting slurry, characterized in that, The pH value circulation detection device for investment casting slurry according to any one of claims 1-8 includes the following steps: Step 1: Drive the probe assembly (3) to the detection station through the lifting mechanism (2) so that the detection end of the probe assembly (3) comes into contact with the slurry to be tested and perform pH value detection; Step 2: After the test is completed, the probe assembly (3) is driven to rise by the lifting mechanism (2) so that the test end returns to the closed cavity and is reset to the cleaning station; Step 3: Inject cleaning fluid into the closed cavity through the liquid supply mechanism (42) to clean the detection end located at the cleaning station; Step 4: Repeat steps 1 to 3 to achieve cyclical pH detection.

10. The method for cyclically detecting the pH value of investment casting slurry according to claim 9, characterized in that, Step three further includes: after the detection end is cleaned, dry gas is delivered into the closed cavity through a pneumatic drying mechanism to air dry the detection end located at the cleaning station.

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