A laboratory slurry automatic filtering and washing instrument

Abstract

The application discloses a kind of laboratory slurry automatic filtration washing instrument, including controller, vacuum system, hot water supply system, filtration washing system and liquid collection system.Vacuum system includes vacuum pump and vacuum distribution system;Hot water supply system includes temperature-controlled water heater, for washing water is heated to preset temperature and keeps constant temperature;Filtration washing system includes N parallelly arranged filtration washing channel, each channel includes funnel, cleaning pipe, control switch valve, suction filter tube and filtration state detection device;Controller judges whether filtration is completed according to the feedback signal of filtration state detection device, and automatically controls the control switch valve of the channel to open after determining that filtration is completed, to realize automatic washing.The application has the advantages of high degree of automation, multi-channel parallel processing, good safety, strong pertinence, good result consistency, etc., can greatly reduce labor intensity, improve analysis efficiency and result accuracy.

Description

Technical Field

[0001] This invention relates to the field of laboratory slurry solid-liquid separation technology, specifically to an automatic laboratory slurry filtration and washing device for automatic filtration, washing, and solid-liquid separation of laboratory slurries. Background Technology

[0002] In laboratory settings, solid-liquid separation is required for determining the chemical composition, physical properties, and liquid-to-solid ratio of slurries. Currently, the primary method used in laboratories for slurry filtration, washing, or solid-liquid separation is vacuum filtration. The equipment used includes glass suction flasks, ceramic funnels, and vacuum pumps. The procedure involves thoroughly mixing the collected slurry, quickly measuring it, filtering under reduced pressure, washing it several times with hot water, and finally removing the filter cake along with filter paper.

[0003] The main problems with this method include:

[0004] (1) The operation is complicated and requires a lot of manpower. It can only process a single sample at a time, and the efficiency is low when multiple batches of samples need to be analyzed.

[0005] (2) The vacuum degree is not adjustable, and the optimal filtration rate cannot be set for various slurry characteristics (such as viscosity, solid content, particle size, etc.), which may lead to filter paper clogging or excessive filtration time.

[0006] (3) When analyzing production control, there are many batches of samples, and traditional methods cannot guarantee the timeliness of the analysis results, which affects production decisions.

[0007] (4) There are many safety hazards during operation, including cuts and scratches caused by broken glassware, burns and corrosion caused by high temperature or harmful liquid splashes, and scalds caused by carelessness when washing with hot water.

[0008] (5) The washing process requires manual water addition multiple times, making it difficult to ensure that the water volume and temperature are consistent each time, which affects the repeatability and accuracy of the analysis results.

[0009] (6) The judgment of whether the filtering is complete depends on the operator’s experience and lacks objective standards, which may lead to insufficient filtering or excessive waiting time.

[0010] Therefore, there is an urgent need for a laboratory slurry solid-liquid separation and washing device that can be automatically controlled, operate in parallel with multiple channels, is safe and reliable, and is highly targeted. Summary of the Invention

[0011] The purpose of this invention is to address the shortcomings of the existing technology by providing an automatic filtration and washing instrument for laboratory slurries, used for automatic filtration, washing, and solid-liquid separation of laboratory slurries.

[0012] To achieve the above objectives, the present invention adopts the following technical solution:

[0013] An automatic slurry filtration and washing device for laboratory use includes a controller, a vacuum system, a hot water supply system, a filtration and washing system, and a liquid collection system, characterized in that:

[0014] The vacuum system includes a vacuum pump (2) and a vacuum distribution system (7);

[0015] The hot water supply system includes a temperature-controlled water heater (3), which is equipped with a heating device, a temperature control device and a water storage space, for heating the washing water to a preset temperature and maintaining a constant temperature.

[0016] The filtration and washing system includes N parallel filtration and washing channels, where N ≥ 2, and each filtration and washing channel includes:

[0017] Funnel (6), wherein filter paper is provided inside the funnel (6) for holding the slurry to be filtered;

[0018] Cleaning pipe (9), one end of which is connected to the temperature-controlled water heater (3), and the other end is located above the funnel (6) and above the surface of the filter paper;

[0019] A control switch valve (8) is installed on the cleaning pipe (9) to control the flow of washing water.

[0020] A vacuum filter tube (10) is provided, with one end connected to the bottom of the funnel (6) and the other end connected to the vacuum distribution system (7).

[0021] A filtration status detection device is used to detect the filtration process of this channel;

[0022] One end of the vacuum distribution system (7) is connected to the vacuum pump (2), and the other end is connected to each of the funnels (6) through each of the suction pipes (10);

[0023] The liquid collection system includes a closed liquid collection tank (17) for collecting the liquid after filtration and washing;

[0024] The controller (1) is electrically connected to each of the control switch valves (8) and each of the filter status detection devices. The controller (1) determines whether the filtration of the corresponding channel is completed according to the feedback signal of the filter status detection device, and automatically controls the control switch valve (8) of the channel to open after the filtration is completed, so as to realize automatic washing.

[0025] The controller (1) also includes a channel status prompting unit, which can independently display the working status of each of the filter washing channels and issue a completion prompt signal after the corresponding channel has completed a preset number of washes.

[0026] Furthermore, the filtration status detection device includes a level gauge and / or a differential pressure sensor;

[0027] When a level gauge is used, the level gauge is set inside the funnel (6) to detect changes in the liquid level inside the funnel; when the liquid level drops to a preset lower threshold and remains at that level for a preset time, it is determined that filtration is complete.

[0028] When a differential pressure sensor is used, the differential pressure sensor is installed on the filtration tube (10) to detect the change in vacuum differential pressure in the channel; when the differential pressure is detected to be stable within a preset range and lasts for a preset time, it is determined that filtration is complete.

[0029] Furthermore, the filtration status detection device includes both a level gauge and a differential pressure sensor, and the controller (1) uses a combined judgment method to determine whether filtration is complete:

[0030] The filtering process is considered complete when all of the following conditions are met:

[0031] The level gauge detected that the liquid level had dropped to the lower threshold.

[0032] The differential pressure sensor detected that the differential pressure was stable and the stabilization time exceeded a preset value;

[0033] The time since the last liquid addition exceeds the minimum filtration time threshold.

[0034] Furthermore, the vacuum distribution system (7) includes a vacuum distribution manifold and N branch pipes, each of the branch pipes being connected to one of the filter washing channels;

[0035] Each of the branch pipes is equipped with:

[0036] Vacuum regulating valve, used to independently adjust the vacuum level of this channel;

[0037] A check valve is used to prevent the channels from interfering with each other through the vacuum system.

[0038] Furthermore, the controller (1) can independently set washing parameters for each of the filter washing channels, the washing parameters including:

[0039] Washing water temperature;

[0040] Number of washes;

[0041] The amount of water added for each wash;

[0042] Duration of each wash.

[0043] Furthermore, the control switch valve (8) is a solenoid valve, and the controller (1) controls the amount of washing water added by controlling the opening time of the solenoid valve;

[0044] The controller (1) pre-calibrates the washing water flow rate and calculates the opening time of the solenoid valve according to the preset water addition amount to achieve quantitative water addition.

[0045] Furthermore, a flow sensor is also provided on the cleaning pipe (9), which is used to monitor the washing water flow rate in real time;

[0046] The controller (1) calculates the actual water volume based on the feedback signal from the flow sensor, and closes the control switch valve (8) when the actual water volume reaches the preset value.

[0047] Furthermore, a spray head is provided at the end of the cleaning tube (9), and multiple spray holes are provided on the spray head. The spray holes are distributed in a circular pattern so that the washing water can be sprayed evenly on the surface of the filter paper.

[0048] Furthermore, the temperature-controlled water heater (3) (with hot water pump) is equipped with a temperature sensor (14) and a level gauge (16). The controller (1) controls the operation of the heating device based on the feedback from the temperature sensor (14) so ​​that the water temperature in the temperature-controlled water heater (3) is maintained within the preset temperature range.

[0049] When the level gauge (16) detects that the water level is lower than the preset lower limit, the controller (1) issues a water replenishment prompt or automatically starts the water replenishment device.

[0050] Furthermore, the channel status indication unit includes:

[0051] An LED indicator array, with multiple LED indicators corresponding to each filter washing channel, used to indicate standby, filtering, washing, and completed states respectively;

[0052] A display screen is used to show the real-time operating parameters and remaining time of each of the filter washing channels;

[0053] A buzzer is used to emit a short beep when a single channel is completed and a continuous beep when all channels are completed.

[0054] Furthermore, the controller (1) also includes a sample information management module, which is capable of recording and displaying the following information:

[0055] The correspondence between sample number and channel number;

[0056] The start and end times of filtration for each sample;

[0057] The actual number of washes and the amount of washing water used for each sample;

[0058] Operator information.

[0059] Furthermore, a gas-liquid separator is provided between the suction tube (10) of each of the filter washing channels and the vacuum distribution system (7). The gas-liquid separator is used to collect any droplets that may be drawn in, preventing liquid from entering the vacuum distribution system (7) and the vacuum pump (2).

[0060] Furthermore, the outer surfaces of the temperature-controlled water heater (3) and each of the funnels (6) are provided with a heat insulation layer (15) to reduce heat loss and maintain temperature stability.

[0061] Furthermore, the upper part of the funnel (6) is provided with a sealing cover, which remains closed during filtration and washing and is opened when the filter cake is removed, so as to reduce the contact time between the filter cake and the air and prevent moisture absorption or oxidation.

[0062] Furthermore, the value of N is 4, meaning that the filtration and washing system includes 4 filtration and washing channels arranged in parallel.

[0063] Compared with the prior art, the present invention has the following beneficial effects:

[0064] (1) High degree of automation: After filtration, the washing is performed automatically. The number of washing cycles, water volume and temperature can be preset, eliminating the need for repeated manual operation and greatly reducing labor intensity.

[0065] (2) Multi-channel parallel processing: It can process multiple samples at the same time, which significantly improves work efficiency and meets the timeliness requirements of production control analysis;

[0066] (3) Good safety: High temperature resistant and corrosion resistant materials are used to avoid safety hazards such as broken glassware, and automated control reduces the chance of personnel coming into contact with harmful substances;

[0067] (4) Highly targeted: parameters such as vacuum degree and washing water temperature can be adjusted independently according to sample characteristics to meet the analysis needs of different slurries;

[0068] (5) Good consistency of results: Automated control ensures that the conditions are consistent for each wash, improving the repeatability and accuracy of the analysis results;

[0069] (6) Intelligent: Multiple sensors are used to monitor the filtration process in real time, accurately determine the timing of filtration completion, and avoid insufficient filtration or excessive waiting time. Attached Figure Description

[0070] Figure 1This is a top view of the automatic slurry filtration and washing device for laboratory use according to the present invention;

[0071] Figure 2 This is a front view of the automatic slurry filtration and washing device for laboratory use according to the present invention;

[0072] Figure 3 This is a side view of the automatic slurry filtration and washing device for laboratory use according to the present invention.

[0073] The annotations in the figure are explained as follows:

[0074] 1-Controller, 2-Vacuum pump, 3-Temperature-controlled water heater, 6-Function funnel, 7-Vacuum distribution system, 8-Control switch valve, 9-Cleaning pipe, 10-Filtering pipe, 14-Temperature sensor, 15-Insulation layer, 16-Level gauge, 17-Sealed collection tank. Detailed Implementation

[0075] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the following embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0076] Example 1

[0077] like Figures 1 to 3 As shown in the figure, this embodiment provides an automatic slurry filtration and washing device for laboratory use, including a controller 1, a vacuum system, a hot water supply system, a filtration and washing system, and a liquid collection system.

[0078] I. Structure of a Vacuum System

[0079] The vacuum system includes a vacuum pump 2 and a vacuum distribution system 7. The vacuum pump 2 is made of stainless steel, has a volume of 20L, and provides a stable negative pressure source. The vacuum pump 2 is connected via piping to a 750W vacuum pump capable of providing a maximum vacuum of -0.09MPa.

[0080] The vacuum distribution system 7 includes a vacuum distribution manifold and four branch lines. The vacuum distribution manifold is made of welded stainless steel tubing with an inner diameter of 32mm. Each branch line is connected to a filter washing channel, and the branch line has an inner diameter of 12mm.

[0081] Each branch line is equipped with a vacuum regulating valve and a check valve. The vacuum regulating valve is a precision needle valve, which can independently adjust the vacuum level of the channel, with an adjustment range of -0.01MPa to -0.09MPa and an adjustment accuracy of ±0.005MPa. The check valve is a stainless steel ball valve with an opening pressure of 0.005MPa, used to prevent mutual interference between channels through the vacuum system and to ensure the independence of each channel.

[0082] II. Structure of Hot Water Supply System

[0083] The hot water supply system includes a temperature-controlled water heater 3. The temperature-controlled water heater 3 uses a stainless steel inner tank with an effective volume of 5L, and is covered with an outer insulation layer 15. The insulation layer 15 is made of polyurethane foam material with a thickness of 30mm, which has excellent heat preservation performance and can reduce heat loss.

[0084] The temperature-controlled water heater 3 is equipped with a heating element using a stainless steel heating tube, with a power of 2000W, capable of quickly heating water to the set temperature. The temperature control device includes a temperature sensor 14 and a temperature controller. The temperature sensor 14 is a platinum resistance thermometer (PT100), with a temperature measurement range of 0-150℃ and an accuracy of ±0.5℃. The temperature sensor 14 is installed in the middle of the temperature-controlled water heater 3, accurately reflecting the water temperature.

[0085] Based on the feedback signal from the temperature sensor 14, the controller 1 controls the operation of the heating device through a PID control algorithm to maintain the water temperature in the temperature-controlled water heater 3 within a preset temperature range. The preset temperature range can be set between 40 and 95℃, with a temperature control accuracy of ±2℃.

[0086] The temperature-controlled water heater 3 is also equipped with a level gauge 16, which is a capacitive level gauge installed on the side wall of the water heater 3. When the level gauge 16 detects that the water level is lower than the preset lower limit (e.g., 20% of the volume), the controller 1 issues an audible and visual alarm to remind the operator to add water. In this embodiment, the temperature-controlled water heater 3 is also connected to an automatic water replenishment device. When the water level is detected to be too low, the controller 1 automatically opens the solenoid valve to replenish water to the temperature-controlled water heater 3 from the water supply pipe until the water level reaches the preset upper limit (e.g., 90% of the volume).

[0087] III. Structure of the Filtration and Washing System

[0088] The filtration and washing system includes four parallel filtration and washing channels, each with the same structure. One of the channels will be used as an example for explanation.

[0089] Each filter washing channel includes a funnel 6. The funnel 6 is made of 304 stainless steel, with an upper inner diameter of 90mm, a lower inner diameter of 25mm, and a height of 120mm. The inner wall of the funnel 6 is polished, resulting in a smooth surface that is easy to clean. Inside the funnel 6 is a porous stainless steel filter plate lined with filter paper. The filter paper is medium-speed quantitative filter paper with a pore size of 5-10μm.

[0090] To reduce heat loss and prevent the temperature drop of the sample during filtration and washing from affecting the washing effect, an insulation layer 15 is provided on the outer surface of the funnel 6. The insulation layer 15 is covered with aluminum silicate fiber felt and has a thickness of 15mm.

[0091] The upper part of funnel 6 is equipped with a sealing cap made of transparent polycarbonate material for easy observation of the filtration process. The sealing cap is connected to funnel 6 via a hinge, allowing for convenient opening and closing. The sealing cap remains closed during filtration and washing to reduce the contact time between the filter cake and air, preventing moisture absorption or oxidation, and also minimizing heat loss. The sealing cap is opened when removing the filter cake. A silicone sealing ring is provided at the interface between the sealing cap and funnel 6 to ensure a tight seal.

[0092] One end of the cleaning pipe 9 is connected to the outlet of the temperature-controlled water heater 3. The pipe is made of high-temperature resistant silicone tubing with an inner diameter of 8mm. The other end of the cleaning pipe 9 is located above the funnel 6 and approximately 50mm above the filter paper surface. A spray head is installed at the end of the cleaning pipe 9. The spray head is made of stainless steel, is disc-shaped, and has a diameter of 60mm. The spray head has 24 spray holes, each with a diameter of 1.5mm, evenly distributed around the circumference. Several spray holes are also located at the center of the spray head. This design ensures that the washing water is evenly sprayed onto the filter paper surface, guaranteeing thorough and uniform washing of the filter cake.

[0093] The control valve 8 is located on the cleaning pipe 9, near the outlet of the temperature-controlled water heater 3. The control valve 8 is a normally closed solenoid valve with a stainless steel body and PTFE sealing material. Its operating pressure range is 0-0.6 MPa, operating temperature range is 0-120℃, and response time is less than 0.1 seconds. The controller 1 precisely controls the amount of washing water added by controlling the opening time of the solenoid valve.

[0094] In this embodiment, the controller 1 pre-calibrates the washing water flow rate. During calibration, under specific temperature (e.g., 70°C) and pressure conditions, the solenoid valve is opened for 10 seconds, and the actual outflow of water is measured. This measurement is repeated three times, and the average value is taken to establish the correspondence between the opening time and the flow rate. In actual use, the controller 1 calculates the time when the solenoid valve should open based on the preset water volume and the calibrated flow rate data, thus achieving quantitative water addition. For example, if the calibrated flow rate is 50 ml / s, and 250 ml of washing water needs to be added, the solenoid valve opening time is 5 seconds.

[0095] To further improve the accuracy of water addition, a flow sensor is installed on the cleaning pipe 9. The flow sensor is a turbine flow meter with a measurement range of 0-500 ml / min and a measurement accuracy of ±2%. The flow sensor is installed downstream of the control switch valve 8.

[0096] Controller 1 calculates the actual water volume added based on real-time feedback signals from the flow sensor. When the cumulative flow reaches a preset value, controller 1 immediately closes the control valve 8, stopping water addition. This closed-loop control method effectively compensates for flow changes caused by fluctuations in water temperature and pressure, ensuring accurate and consistent water addition for each wash.

[0097] One end of the filtration tube 10 is connected to the bottom of the funnel 6 via a flange, and the other end is connected to the corresponding branch line of the vacuum distribution system 7. The filtration tube 10 is made of high-temperature and corrosion-resistant polytetrafluoroethylene flexible tubing with an inner diameter of 12mm, capable of withstanding a vacuum of -0.1MPa.

[0098] A gas-liquid separator is installed between the filtration tube 10 and the vacuum distribution system 7. The gas-liquid separator is made of stainless steel, has a volume of 500ml, and features an internal cyclone separation structure. The function of the gas-liquid separator is to collect any liquid droplets that may be drawn in, preventing liquid from entering the vacuum distribution system 7 and the vacuum pump 2, thus avoiding damage to the vacuum pump. A drain valve is located at the bottom of the gas-liquid separator to periodically drain the collected liquid.

[0099] IV. Structure of the Filtration Status Detection Device

[0100] Each filter washing channel is equipped with a filter status detection device to monitor the filtration process of the channel in real time, providing accurate data for automatic control.

[0101] In this embodiment, the filtration status detection device includes a level gauge and a differential pressure sensor. A combined judgment method is used to determine whether filtration is complete, thereby improving the accuracy and reliability of the judgment.

[0102] The level gauge is installed inside funnel 6 and is a photoelectric level gauge, positioned 5mm above the filter paper surface. The level gauge detects the presence of liquid in the funnel by emitting and receiving infrared light. When there is liquid in the funnel, the infrared light is absorbed or scattered by the liquid, and the receiver receives little or no signal. When the liquid level drops below the level gauge, the infrared light is reflected back by the reflector on the opposite side, and the receiver receives a strong signal, indicating that the liquid level has dropped to a preset lower threshold.

[0103] A differential pressure sensor is installed on the filtration tube 10, near the funnel 6. The differential pressure sensor is a capacitive type, with a measurement range of 0–0.1 MPa and a measurement accuracy of ±0.001 MPa. One end of the sensor is connected to the inside of the filtration tube 10 to measure the vacuum level within the tube; the other end is connected to the atmosphere as a reference pressure. By measuring the pressure difference between the two ends, the vacuum pressure difference within the filtration tube can be obtained.

[0104] During the filtration process, as liquid is continuously removed from the slurry, the liquid level in the funnel gradually decreases, and the vacuum pressure difference in the suction tube also changes. Once the filter cake is formed and the liquid has been largely removed, the vacuum pressure difference tends to stabilize.

[0105] Controller 1 uses a combined judgment method to determine whether filtering is complete. The specific judgment logic is as follows:

[0106] The filtering process is considered complete when all three of the following conditions are met:

[0107] Condition 1: The level gauge detects that the liquid level has dropped to the lower threshold, that is, the output signal of the level gauge jumps from low to high, indicating that the liquid level in the funnel has dropped to near the surface of the filter paper.

[0108] Condition 2: The differential pressure sensor detects that the differential pressure is stable, that is, the rate of change of the vacuum differential pressure is less than 0.001 MPa / min, and the stabilization time exceeds the preset value (e.g., 30 seconds), indicating that the filtration rate has become very slow and the filter cake has basically formed.

[0109] Condition 3: The time since the last liquid addition (start of filtration or last wash) exceeds the minimum filtration time threshold (e.g., 60 seconds). This is to prevent misjudgment caused by excessively fast slurry pouring speed or other instantaneous factors.

[0110] This combined judgment method can accurately and reliably determine whether filtration is complete, avoiding misjudgments that may occur with a single judgment method, and ensuring that the automatic washing program is started at the optimal time.

[0111] V. Structure of the Liquid Collection System

[0112] The liquid collection system includes a closed-loop liquid collection tank 17. The closed-loop liquid collection tank 17 is made of polypropylene, has a volume of 30L, and exhibits good corrosion resistance. The suction pipes 10 of each filtration and washing channel ultimately converge into the closed-loop liquid collection tank 17 via a gas-liquid separator.

[0113] The sealed collection tank 17 is equipped with a drain valve at the bottom for periodic discharge of the collected filtrate. A level gauge is located at the top of the sealed collection tank 17 to visually display the current liquid level and prevent overflow. When the liquid level reaches the set high alarm value, the controller 1 issues an audible and visual alarm.

[0114] VI. Structure and Functions of the Controller

[0115] The controller 1 is the core of the entire device, responsible for coordinating and controlling the work of various subsystems to realize an automated filtration and washing process.

[0116] Controller 1 uses a PLC (Programmable Logic Controller) as the main control unit, specifically a Siemens S7-1200, which features high reliability and powerful processing capabilities. The PLC connects to various sensors via digital input modules and controls various actuators (such as solenoid valves and heaters) via digital output modules.

[0117] The controller 1 is electrically connected to each of the control valves 8 and each of the filter status detection devices (including level gauges and differential pressure sensors). The controller 1 collects signals from each sensor in real time, processes them according to preset control logic, and outputs corresponding control signals.

[0118] Controller 1 determines whether filtering for a corresponding channel is complete based on feedback signals from the filtering status detection device. When it is determined that filtering for a channel is complete, controller 1 automatically performs the following operations:

[0119] (1) Wait for the preset dripping time (e.g., 10 seconds) to ensure that the residual liquid in the filter cake drips off completely;

[0120] (2) Open the control switch valve 8 of this channel to start adding hot washing water. The amount of water added is determined according to the preset parameters, generally 100-500ml;

[0121] (3) Washing water is evenly sprayed onto the surface of the filter cake through the spray head to soak and wash the filter cake;

[0122] (4) After water is added, controller 1 closes control switch valve 8, maintains vacuum filtration, and draws washing water through the filter cake to remove soluble impurities.

[0123] (5) Use the filter status detection device again to determine whether the filtration of this wash is complete;

[0124] (6) Repeat steps (1) to (5) until the preset number of washes is completed.

[0125] Controller 1 can independently set washing parameters for each filter washing channel, the washing parameters including:

[0126] Washing water temperature: can be set in the range of 40-95℃. Choose the appropriate temperature according to the characteristics of the sample, and generally set it to 60-80℃.

[0127] Washing frequency: can be set to 1-10 times, generally set to 3-5 times;

[0128] The amount of water added for each wash can be set within the range of 50-500 ml, depending on the sample volume and analytical requirements;

[0129] The duration of each wash, i.e. the soaking time, can be set in the range of 10-300 seconds. For samples that require thorough washing, the soaking time can be extended.

[0130] Different channels can be set with different parameters, which allows for the simultaneous processing of samples of different types or with different analytical requirements, greatly improving the flexibility and applicability of the equipment.

[0131] The controller 1 also includes a channel status prompt unit, which can independently display the working status of each filter washing channel and issue a completion prompt signal after the corresponding channel has completed a preset number of washes.

[0132] The channel status indication unit includes:

[0133] LED indicator array: Located on the front panel of the equipment, each filter washing channel corresponds to a set of LED indicators, including four indicators of different colors, used to indicate standby (white), filtering (blue), washing (yellow), and completed (green). Operators can intuitively understand the working status of each channel through the color and flashing status of the LED indicators;

[0134] Display screen: A 7-inch color touchscreen with a resolution of 800×480 pixels. The screen displays real-time operating parameters and remaining time for each filter washing channel, including current status, number of washes completed, number of washes remaining, current vacuum level, wash water temperature, and estimated completion time. Operators can also use the touchscreen to set parameters, start / stop operations, and query historical records.

[0135] Buzzer: Used to provide audible alerts. When a single channel completes its entire washing process, the buzzer emits a short "beep" sound, indicating that the channel is finished and the filter cake can be removed. When all four channels have completed their processes, the buzzer emits a continuous "beep-beep-beep" sound, indicating that all samples have been processed. The buzzer volume is adjustable to avoid excessive noise interference in the laboratory environment.

[0136] Controller 1 also includes a sample information management module, which can record and display the following information:

[0137] Correspondence between sample number and channel number: Before pouring the slurry, the operator enters the sample number through the touch screen, and the system automatically establishes the correspondence between the sample and the channel to avoid confusion;

[0138] Filtration start and end times for each sample: The system automatically records the start time of filtration and the time of completion of all washing for each sample, facilitating traceability and quality control;

[0139] Actual number of washes and amount of washing water used for each sample: The system records the actual number of washes performed and the cumulative amount of washing water used, which can be used to analyze the integrity of the data.

[0140] Operator information: The system supports multi-user management. Operators log in with a username and password. The system records the operator for each sample, which facilitates accountability.

[0141] All recorded data can be exported to Excel or CSV format for easy data analysis and report compilation. The system supports storing no fewer than 10,000 historical records, and the data is stored using non-volatile memory, ensuring data integrity even after power failure.

[0142] VII. Work Process

[0143] The working process of the automatic slurry filtration and washing device for laboratory use of this invention is as follows:

[0144] (1) Equipment preheating and parameter settings:

[0145] The operator turns on the equipment power, and controller 1 starts a self-test program to check the working status of each sensor and actuator. The temperature-controlled water heater 3 starts heating, heating the water to the preset temperature and maintaining it at a constant temperature, which generally takes 15-20 minutes to reach a stable state.

[0146] Operators set corresponding operating parameters for each channel via a touchscreen, based on the characteristics of the sample to be tested. These parameters include vacuum level, washing water temperature, number of washes, and water volume per wash. For standard samples, preset standard parameter combinations can be used.

[0147] (2) Sample preparation and loading:

[0148] Operators lay filter paper of the appropriate size in each funnel 6, ensuring that the filter paper is flat, wrinkle-free, and that the edges fit well against the funnel wall.

[0149] Thoroughly stir the sampled slurry to ensure uniform dispersion of solid particles. Accurately measure the specified volume of slurry using a graduated cylinder, record the sample number, and input the sample number via the touchscreen to establish the correspondence between the sample and the channel.

[0150] According to the corresponding number, slowly pour the slurry into the funnel 6, avoiding overflow or tearing the filter paper. Cover the funnel with the sealing cap.

[0151] (3) Start the filtering program:

[0152] The operator clicks the "Start" button on the touch screen, and controller 1 starts the filtering program for the corresponding channel.

[0153] The vacuum system starts working, applying negative pressure to the funnel 6 through the suction tube 10. Under the action of negative pressure, the liquid in the slurry is drawn away through the filter paper, and the solid particles are trapped on the filter paper, gradually forming a filter cake.

[0154] During the filtration process, a filtration status monitoring device continuously monitors the filtration progress. A level gauge detects changes in the liquid level inside the funnel, and a differential pressure sensor detects changes in the vacuum differential pressure inside the suction tube.

[0155] Controller 1 analyzes sensor signals in real time and determines whether filtration is complete based on combined judgment logic. A flashing blue LED indicates that filtration is in progress in that channel. The touchscreen displays parameters such as current vacuum level and filtration time.

[0156] (4) Automatic washing program:

[0157] Once controller 1 determines that filtration in a certain channel is complete, it automatically initiates the washing program. Controller 1 first maintains a vacuum state for 10 seconds to allow the residual liquid in the filter cake to drip off completely.

[0158] Subsequently, controller 1 opens the control switch valve 8 of this channel, and hot washing water flows in from the temperature-controlled water heater 3 through the cleaning pipe 9, and is evenly sprayed onto the surface of the filter cake through the spray head. The flow sensor monitors the water flow in real time, and controller 1 calculates the cumulative water addition. When the preset value is reached, control switch valve 8 is closed.

[0159] The filter cake is soaked in washing water for a preset duration (e.g., 30 seconds) to dissolve and remove soluble impurities from the filter cake.

[0160] After soaking, the vacuum system continues to work, drawing the washing water through the filter cake, and the washing liquid flows into the closed collection tank 17 through the suction pipe 10 and the gas-liquid separator.

[0161] Controller 1 then uses the filter status detection device to determine whether the filtration for this wash is complete. Once completed, the washing process is repeated until the preset number of washes is completed.

[0162] During the washing process, the LED indicator flashes yellow, and the touchscreen displays information such as the current number of washes and the number of washes remaining.

[0163] (5) Complete the prompts and sampling:

[0164] Once a channel has completed the entire washing process, controller 1 shuts off the vacuum supply to that channel, the LED indicator turns solid green, the buzzer emits a short "beep" sound, and the touchscreen displays that the channel has finished and can be sampled.

[0165] Following the instructions, the operator opens the sealing cap of the corresponding funnel, uses tweezers to remove the filter paper along with the filter cake, and places it into a pre-marked container for subsequent drying, weighing, or other analysis.

[0166] When all channels are completed, the buzzer emits a continuous "beep-beep-beep" sound to indicate that all samples have been processed.

[0167] (6) Cleaning and maintenance:

[0168] Operators should clean the funnel, spray head, and other parts that come into contact with the sample to prevent cross-contamination. Regularly check the operating status of all sensors and valves, calibrating or replacing them as necessary. Drain the filtrate from the sealed collection tank 17 and clean the tank.

[0169] Example 2

[0170] Based on Example 1, this embodiment simplifies the filtration status detection device and adopts a single level gauge.

[0171] Specifically, the filtration status detection device includes only a level gauge, which is installed inside the funnel 6. It is a capacitive level gauge installed on the inner wall of the funnel, and the detection position is 3mm above the surface of the filter paper.

[0172] When there is liquid in the funnel, the capacitance of the level gauge is relatively large; when the liquid level drops below the sensor, the capacitance decreases significantly. Controller 1 determines whether the liquid level has dropped to a preset lower threshold by detecting the change in capacitance.

[0173] When the liquid level is detected to drop to the preset lower threshold, controller 1 starts a delay timer for a preset time, such as 20 seconds. If the liquid level remains below the lower threshold within the preset time, filtration is considered complete; if the liquid level rises above the lower threshold again (possibly due to short-term liquid accumulation caused by partial blockage of the filter paper), the timer restarts.

[0174] This method has a relatively simple logic and is suitable for slurry samples with low solid content, fast filtration speed, and thin filter cake.

[0175] The other structures and workflows of this embodiment are the same as those of Embodiment 1, and will not be repeated here.

[0176] Example 3

[0177] Based on Example 1, this embodiment simplifies the filter status detection device by using a single differential pressure sensor.

[0178] Specifically, the filtration status detection device includes only a differential pressure sensor, which is installed on the suction tube 10 near the vacuum distribution system 7. It is a piezoresistive differential pressure sensor with a measurement range of 0-0.1 MPa and a measurement accuracy of ±0.002 MPa.

[0179] During the filtration process, as the filter cake thickness increases and the filter paper pores become partially blocked, the filtration resistance gradually increases, and the vacuum pressure difference also increases accordingly. When the filter cake is basically formed and the liquid is almost completely drained, the vacuum pressure difference tends to stabilize and approaches the system's ultimate vacuum level due to the lack of liquid flow.

[0180] Controller 1 acquires signals from the differential pressure sensor in real time and calculates the rate of change of the vacuum differential pressure. When the detected rate of change of differential pressure is less than a preset threshold (e.g., 0.001 MPa / min), it indicates that the differential pressure is stabilizing.

[0181] When the differential pressure stabilization time exceeds the preset time (e.g., 40 seconds), the filtering is considered complete.

[0182] This method is suitable for slurry samples with high solids content, thick filter cake, and significant changes in filtration resistance. The progress of the filtration process can be sensitively reflected by changes in pressure difference.

[0183] The other structures and workflows of this embodiment are the same as those of Embodiment 1, and will not be repeated here.

[0184] Example 4

[0185] Based on Example 1, this embodiment improves the control method of the control switch valve by adopting a dual guarantee method that combines time control and flow feedback, which further improves the accuracy of water addition and the reliability of the system.

[0186] Specifically, a flow sensor is installed on the cleaning pipe 9. The flow sensor is an electromagnetic flow meter with a measurement range of 0-1000 ml / min, a measurement accuracy of ±1%, and a response time of less than 0.5 seconds.

[0187] During the water addition process, controller 1 employs the following control strategy:

[0188] (1) Calculate the theoretical time T that the solenoid valve should open based on the pre-calibrated flow data;

[0189] (2) Open the control switch valve 8 and start the timer and flow accumulation simultaneously;

[0190] (3) Read the signal from the flow sensor in real time and calculate the actual water volume V_actual;

[0191] (4) Close control valve 8 when any of the following conditions are met:

[0192] Condition A: The timer reaches Ttheoretical × 1.2 (i.e., 120% of the theoretical time) as an overtime protection to prevent continuous water filling when the flow sensor fails;

[0193] Condition B: V actually reaches the preset water addition amount V set.

[0194] Under normal circumstances, condition B is met first, and the system performs precise control based on flow feedback; when the flow sensor malfunctions or water addition is abnormal, condition A plays a protective role to prevent excessive water addition.

[0195] This dual control method combines high precision and high reliability, making it suitable for analytical tasks that require extremely high accuracy in water addition.

[0196] The other structures and workflows of this embodiment are the same as those of Embodiment 1, and will not be repeated here.

[0197] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An automatic slurry filtration and washing device for laboratory use, comprising a controller, a vacuum system, a hot water supply system, a filtration and washing system, and a liquid collection system, characterized in that: The vacuum system includes a vacuum pump (2) and a vacuum distribution system (7); The hot water supply system includes a temperature-controlled water heater (3), which is equipped with a heating device, a temperature control device and a water storage space, for heating the washing water to a preset temperature and maintaining a constant temperature. The filtration and washing system includes N parallel filtration and washing channels, where N ≥ 2, and each filtration and washing channel includes: Funnel (6), wherein filter paper is provided inside the funnel (6) for holding the slurry to be filtered; Cleaning pipe (9), one end of which is connected to the temperature-controlled water heater (3), and the other end is located above the funnel (6) and above the surface of the filter paper; A control switch valve (8) is installed on the cleaning pipe (9) to control the flow of washing water. A vacuum filter tube (10) is provided, with one end connected to the bottom of the funnel (6) and the other end connected to the vacuum distribution system (7). A filtration status detection device is used to detect the filtration process of this channel; One end of the vacuum distribution system (7) is connected to the vacuum pump (2), and the other end is connected to each of the funnels (6) through each of the suction pipes (10); The liquid collection system includes a closed liquid collection tank (17) for collecting the liquid after filtration and washing; The controller (1) is electrically connected to each of the control switch valves (8) and each of the filter status detection devices. The controller (1) determines whether the filtration of the corresponding channel is completed according to the feedback signal of the filter status detection device, and automatically controls the control switch valve (8) of the channel to open after the filtration is completed, so as to realize automatic washing. The controller (1) also includes a channel status prompting unit, which can independently display the working status of each of the filter washing channels and issue a completion prompt signal after the corresponding channel has completed a preset number of washes.

2. The automatic laboratory slurry filtration and washing device according to claim 1, characterized in that, The filtration status detection device includes a level gauge and / or a differential pressure sensor; When a level gauge is used, the level gauge is set inside the funnel (6) to detect changes in the liquid level inside the funnel; when the liquid level drops to a preset lower threshold and remains at that level for a preset time, it is determined that filtration is complete. When a differential pressure sensor is used, the differential pressure sensor is installed on the filtration tube (10) to detect the change in vacuum differential pressure in the channel; when the differential pressure is detected to be stable within a preset range and lasts for a preset time, it is determined that filtration is complete.

3. The automatic laboratory slurry filtration and washing device according to claim 2, characterized in that, The filtration status detection device includes both a level gauge and a differential pressure sensor, and the controller (1) uses a combined judgment method to determine whether filtration is complete: The filtering process is considered complete when all of the following conditions are met: The level gauge detected that the liquid level had dropped to the lower threshold. The differential pressure sensor detected that the differential pressure was stable and the stabilization time exceeded a preset value; The time since the last liquid addition exceeds the minimum filtration time threshold.

4. The automatic laboratory slurry filtration and washing apparatus according to claim 1, characterized in that, The vacuum distribution system (7) includes a vacuum distribution manifold and N branch lines, each of the branch lines being connected to one of the filter washing channels; Each of the branch pipes is equipped with: Vacuum regulating valve, used to independently adjust the vacuum level of this channel; A check valve is used to prevent the channels from interfering with each other through the vacuum system.

5. The automatic laboratory slurry filtration and washing apparatus according to claim 1, characterized in that, The controller (1) can independently set washing parameters for each of the filter washing channels, the washing parameters including: Washing water temperature; Number of washes; The amount of water added for each wash; Duration of each wash.

6. The automatic laboratory slurry filtration and washing apparatus according to claim 1, characterized in that, The control switch valve (8) is a solenoid valve, and the controller (1) controls the amount of washing water added by controlling the opening time of the solenoid valve; The controller (1) pre-calibrates the washing water flow rate and calculates the opening time of the solenoid valve according to the preset water addition amount to achieve quantitative water addition.

7. The automatic laboratory slurry filtration and washing apparatus according to claim 1, characterized in that, A flow sensor is also provided on the cleaning pipe (9), which is used to monitor the washing water flow rate in real time; The controller (1) calculates the actual water volume based on the feedback signal from the flow sensor, and closes the control switch valve (8) when the actual water volume reaches the preset value.

8. The automatic laboratory slurry filtration and washing apparatus according to claim 1, characterized in that, The end of the cleaning pipe (9) is provided with a spray head, and the spray head has multiple spray holes distributed in a circumferential manner so that the washing water can be sprayed evenly on the surface of the filter paper.

9. The automatic laboratory slurry filtration and washing apparatus according to claim 1, characterized in that, The temperature-controlled water heater (3) (with hot water pump) is equipped with a temperature sensor (14) and a level gauge (16). The controller (1) controls the operation of the heating device according to the feedback of the temperature sensor (14) so ​​that the water temperature in the temperature-controlled water heater (3) is kept within the preset temperature range. When the level gauge (16) detects that the water level is lower than the preset lower limit, the controller (1) issues a water replenishment prompt or automatically starts the water replenishment device.

10. The automatic laboratory slurry filtration and washing apparatus according to claim 1, characterized in that, The channel status indication unit includes: An LED indicator array, with multiple LED indicators corresponding to each filter washing channel, used to indicate standby, filtering, washing, and completed states respectively; A display screen is used to show the real-time operating parameters and remaining time of each of the filter washing channels; A buzzer is used to emit a short beep when a single channel is completed and a continuous beep when all channels are completed.

11. The automatic laboratory slurry filtration and washing apparatus according to claim 1, characterized in that, The controller (1) also includes a sample information management module, which is capable of recording and displaying the following information: The correspondence between sample number and channel number; The start and end times of filtration for each sample; The actual number of washes and the amount of washing water used for each sample; Operator information.

12. The automatic laboratory slurry filtration and washing apparatus according to claim 1, characterized in that, A gas-liquid separator is provided between the suction tube (10) of each of the filter washing channels and the vacuum distribution system (7). The gas-liquid separator is used to collect any droplets that may be drawn in, and to prevent liquid from entering the vacuum distribution system (7) and the vacuum pump (2).

13. The automatic laboratory slurry filtration and washing apparatus according to claim 1, characterized in that, The outer surfaces of the temperature-controlled water heater (3) and each of the funnels (6) are provided with a heat insulation layer (15) to reduce heat loss and maintain a stable temperature.

14. The automatic laboratory slurry filtration and washing apparatus according to claim 1, characterized in that, The upper part of the funnel (6) is provided with a sealing cover, which remains closed during filtration and washing and is opened when the filter cake is removed to reduce the contact time between the filter cake and the air and prevent moisture absorption or oxidation.

15. The automatic laboratory slurry filtration and washing apparatus according to claim 1, characterized in that, The value of N is 4, meaning that the filtration and washing system includes 4 filtration and washing channels arranged in parallel.

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