A sludge moisture content detection device and measurement method based on true density

Abstract

This invention discloses a sludge moisture content detection device based on true density, comprising a sample chamber. The device is characterized by having a detection unit within the sample chamber, a compression unit on one side of the sample chamber, and the compression unit being installed within a support device. The detection unit includes a pressure sensor, a gravity sensor, and a limit sensor. The pressure sensor is installed on the side wall of the sample chamber, the gravity sensor is installed at the bottom of the sample chamber, and a sample tray is located above the gravity sensor. The limit sensor is located at the connection between the sample chamber and the compression unit. The compression unit includes a power drive base connected to a hydraulic rod, which is connected to a piston. The sludge moisture content detection device and method provided by this invention are simple, have a short measurement time, and utilize a non-contact method to eliminate the influence of porosity, ensuring the accuracy of sludge true density calculation and thus determining the detection accuracy of sludge moisture content.

Description

Technical Field

[0001] This invention relates to the field of sludge moisture content measurement technology, and in particular to a sludge moisture content detection device and measurement method based on true density. Background Technology

[0002] The national sludge production is increasing year by year, resulting in significant disposal pressure. Sludge dewatering and drying are important means to reduce sludge volume, and various sludge treatment and disposal methods have certain requirements for moisture content. Therefore, sludge moisture content is related to whether sludge treatment and disposal meet the standards and is an important testing indicator in this field.

[0003] Currently, the main methods for measuring sludge moisture content include drying, microwave, and near-infrared methods. Drying requires drying the sludge, which is time-consuming; microwave methods require establishing the relationship between dielectric constant and moisture content; and near-infrared methods require establishing the relationship between wavelength and moisture content, making the measurement methods complex and the instruments expensive. There are also probe-based measurement methods, but these have a narrow measurement range and low accuracy.

[0004] This device and method can quickly and accurately measure the moisture content of sludge by introducing only the true density of the sludge. The required equipment has a simple structure, the measurement time is short, and the measurement efficiency can be greatly improved. Summary of the Invention

[0005] The purpose of this invention is to provide a sludge moisture content detection device and measurement method based on true density, so as to solve the problems mentioned in the background art, eliminate the influence of pores through a non-contact method, and ensure the accuracy of sludge true density calculation.

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

[0007] A sludge moisture content detection device based on true density includes a sample chamber containing a detection device. A compression device is located on one side of the sample chamber and is installed within a support device. The detection device includes a pressure sensor, a gravity sensor, and a limit sensor. The pressure sensor is installed on the side wall of the sample chamber, the gravity sensor is installed at the bottom of the sample chamber, and a sample tray is located above the gravity sensor. The limit sensor is located at the connection between the sample chamber and the compression device. The compression device includes a power drive base connected to a hydraulic rod, which is connected to a piston. A compression cylinder is located on one side of the piston. The support device includes a top plate with multiple inner and outer support columns connected to it. One side of each inner support column is connected to the top plate, and the other side is connected to the compression cylinder. One side of each outer support column is connected to the edge of the top plate, and the other side is connected to the sample chamber.

[0008] Preferably, it further includes an information processing and display device, which is connected to the detection device. The information processing and display device includes a processor and a display. The processor is electrically connected to the pressure sensor, the gravity sensor and the limit sensor respectively, and the display is connected to the processor.

[0009] Preferably, there are 4 inner support columns and 4 outer support columns. The inner support columns fix the top plate and the extrusion cylinder respectively, and the outer support columns fix the power drive seat and the sample chamber.

[0010] Preferably, the inner support column is connected to the extrusion cylinder, enabling the hydraulic rod, piston, and extrusion cylinder to be on the same axis.

[0011] Preferably, the extrusion cylinder has an exhaust port on its side, which is located at the upper end of the extrusion cylinder, and the distance between the exhaust port and the left edge of the extrusion cylinder is not less than the thickness of the piston.

[0012] Preferably, a through hole is provided between the sample chamber and the detection device to connect the sample chamber and the detection device. A limit sensor is provided on the through hole, and the limit sensor is connected to the through hole through a limit rod. The volume of the extrusion cylinder from the exhaust port to the limit sensor is known.

[0013] Preferably, the sample chamber is provided with a door at the front end, the door is provided with a sealing strip, the sample tray is installed on the bottom column, and a gravity sensor is provided on the bottom column.

[0014] Preferably, a method for measuring sludge moisture content using a true density-based sludge moisture content detection device includes the following steps:

[0015] S1: Open the chamber door, place the empty container for holding the sludge sample to be tested on the tray above the gravity sensor inside the sample chamber, close the chamber door tightly, process it through the processor, and display the recorded mass m0 on the display.

[0016] S2: When the air pressure is stable after the door is closed, record the air pressure sensor value as P0. Start the hydraulic rod through the power drive seat. After the hydraulic rod pushes the piston to the limit sensor, the limit sensor transmits the limit signal to the processor. The processor sends a signal to stop pushing the hydraulic rod. After waiting for a few seconds for the air pressure to stabilize, record the air pressure sensor value P1.

[0017] S3: Open the chamber door again, place the container that has contained the sludge sample on the tray above the gravity sensor inside the sample chamber, close the chamber door tightly, process it through the processor, and display the recorded mass m1 on the display.

[0018] S4: When the air pressure stabilizes after closing the door again, record the air pressure sensor value as P2. Start the hydraulic rod through the power drive seat. After the hydraulic rod pushes the piston to the limit sensor, the limit sensor transmits the limit signal to the processor. The processor sends a signal to stop pushing the hydraulic rod. After waiting for a few seconds for the air pressure to stabilize, record the air pressure sensor value as P3.

[0019] Since the volume of the extrusion cylinder from the exhaust port to the limit sensor is known, it is set to V.

[0020] Calculate the sludge moisture content using the following formula:

[0021]

[0022]

[0023] Where ρ s The dry basis density of the sludge is ρ. s = -0.5sin(t / 12π) + 2.6g / cm 3 t represents the month, taking any value from 1 to 12, or, using the sludge true density measurement method described in this invention, several portions of sludge are dried to an absolutely dry state, their true density is measured, and the average value is taken as the sludge dry basis density for the current month; ρ l The density of water is 1 g / cm³. 3 .

[0024] Preferably, the processor receives and processes signals from the pressure sensor, gravity sensor, and limit sensor respectively, converts the signals into digital signals of mass and pressure, calculates the sludge moisture content according to the calculation formula, and saves and displays the data.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] 1. This method can accurately reflect the relationship between sludge moisture content and true density. It removes the influence of pores in the sludge by air removal, obtains the true density of the sludge, and then calculates its moisture content.

[0027] 2. By utilizing the sealing performance of the sample chamber, the hydraulic rod pushes the piston into the extrusion cylinder under the influence of the power drive seat. This allows the internal pressure of the extrusion cylinder to be injected into the sample chamber for pressurization. The device then measures the pressure change after pressurization, compares the pressure inside the empty chamber with that inside the sample chamber, calculates the sludge volume and weight, and tests the moisture content.

[0028] 3. The information processing and display device completes the information transmission and calculation of the barometric pressure sensor and gravity sensor, completes the data collection and comparison, realizes the automation and intelligence of the device operation process, makes the testing process more convenient, and significantly improves the testing efficiency.

[0029] 4. The support device is connected and fixed to the sample chamber by the support of the inner and outer pillars. At the same time, the hydraulic cylinder of the inner pillar is pushed horizontally to ensure the extrusion effect of the extrusion cylinder.

[0030] 5. The volume of the extrusion cylinder from the exhaust port to the limit sensor at the connection between the extrusion cylinder and the sample chamber is known, and the volume of the extrusion cylinder should not be greater than the volume of the sample chamber to prevent excessive air pressure. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall structure and principle of the sludge moisture content detection device based on true density according to the present invention.

[0032] Figure 2 This is a schematic diagram of the information processing and display device of the present invention.

[0033] Figure 3 This is a comparison chart of the true density data calculated by the formula of this invention and the measured sludge moisture content.

[0034] Figure 4 This is a side view of the device for measuring the moisture content of sludge according to the present invention.

[0035] Reference numerals: 1. Top plate; 2. Hydraulic rod; 3. Inner support column; 4. Outer support column; 5. Piston; 6. Exhaust port; 7. Squeezing cylinder; 8. Sample chamber; 9. Pressure sensor; 10. Gravity sensor; 11. Limit sensor; 12. Chamber door; 13. Detection device; 14. Compression device; 15. Power drive seat; 16. Support device; 17. Information processing and display device; 18. Processor; 19. Display; 21. Through hole; 22. Limit rod; 23. Bottom column. Detailed Implementation

[0036] The following description, in conjunction with the accompanying drawings, provides a detailed account of specific embodiments of the present invention.

[0037] Example 1

[0038] A sludge moisture content detection device based on true density includes a sample chamber 8, a detection device 13 disposed inside the sample chamber 8, and a compression device 14 disposed on one side of the sample chamber 8. The compression device 14 is installed in a support device 16. The detection device 13 includes a pressure sensor 9, a gravity sensor 10, and a limit sensor 11. The pressure sensor 9 is installed on the side wall of the sample chamber 8, the gravity sensor 10 is installed at the bottom of the sample chamber, and a sample tray is disposed above the gravity sensor. The limit sensor is disposed at the connection between the sample chamber 8 and the compression device 14. The compression device 14 includes a power drive base 15, and a hydraulic rod 2 is connected to the power drive base 15. The pressure rod 2 is connected to the piston 5. A squeezing cylinder 7 is provided on one side of the piston 5. The support device 16 includes a top plate 1. Multiple inner support columns 3 and outer support columns 4 are connected to the top plate 1. One side of the inner support column 3 is connected to the top plate 1, and the other side of the inner support column 3 is connected to the squeezing cylinder 7. One side of the outer support column 4 is connected to the edge of the top plate 1, and the other side of the outer support column 4 is connected to the sample chamber 8. Through the sealing performance of the sample chamber 8, under the influence of the power drive seat 15, the hydraulic rod 2 pushes the piston 5 into the squeezing cylinder 7, so that the internal pressure of the squeezing cylinder 7 is injected into the sample chamber for pressurization. This allows for the change of the measured pressure of the device after pressurization, and the comparison of the pressure in the empty chamber with that in the sample chamber. The volume weight of the sludge is calculated to achieve the moisture content and test.

[0039] Preferably, the device further includes an information processing and display device 17, which is connected to the detection device 13. The information processing and display device 17 includes a processor 18 and a display 19. The processor 18 is electrically connected to the pressure sensor 9, the gravity sensor 10, and the limit sensor 11, respectively. The display 19 is connected to the processor 18. The information processing and display device 17 completes the information transmission and calculation of the pressure sensor 9 and the gravity sensor 10, completes the data collection and comparison, realizes the automation and intelligence of the device operation process, makes the testing process more convenient, and significantly improves the testing efficiency.

[0040] Preferably, there are four inner support columns 3 and four outer support columns 4. The inner support columns 3 fix the top plate 1 and the extrusion cylinder 7 respectively, and the outer support columns 4 fix the power drive seat 15 and the sample chamber 8. The support of the inner support columns 3 and the outer support columns 4 realizes the connection and fixation between the support device and the sample chamber 8, and at the same time can ensure that the extrusion cylinder of the inner support column 3 is pushed horizontally to ensure the extrusion effect of the extrusion cylinder.

[0041] Preferably, the connection between the inner support column 3 and the extrusion cylinder 7 enables the hydraulic rod, piston, and extrusion cylinder to be on the same axis.

[0042] Preferably, the side of the extrusion cylinder 7 is provided with an exhaust port 6, which is located at the upper end of the extrusion cylinder 7. The distance between the exhaust port 6 and the left edge of the extrusion cylinder 7 is not less than the thickness of the piston 5. The volume of the extrusion cylinder from the exhaust port 6 to the limit sensor 11 at the connection between the extrusion cylinder 7 and the sample chamber 8 is known, and the volume of the extrusion cylinder 7 should not be greater than the volume of the sample chamber to prevent excessive air pressure.

[0043] Preferably, a through hole 21 is provided between the sample chamber 8 and the detection device 13, through which the sample chamber 8 and the detection device 13 are connected. A limit sensor 11 is provided on the through hole 21, and the limit sensor 11 is connected to the through hole 21 through a limit rod 22.

[0044] Preferably, the sample chamber 8 is provided with a door 12 at the front end, the door 12 is provided with a sealing strip, the sample tray is installed on the bottom column 23, and the bottom column 23 is provided with a gravity sensor 10.

[0045] Preferably, a method for measuring sludge moisture content using a true density-based sludge moisture content detection device includes the following steps:

[0046] S1: Open the chamber door 12, place the empty container for holding the sludge sample to be tested on the tray above the gravity sensor 10 in the sample chamber 8, close the chamber door 12, process it through the processor 18, and display the recorded mass m0 on the display 19.

[0047] S2: When the air pressure is stable after closing the door 12, record the value of the air pressure sensor 9 as P0. Start the hydraulic rod 2 through the power on the power drive seat 15. The hydraulic rod 2 pushes the piston 5 to the limit sensor 11. The limit sensor 11 transmits the limit signal to the processor 18. The processor 18 sends a signal to stop pushing the hydraulic rod 2. After waiting for a few seconds for the air pressure to stabilize, record the value of the air pressure sensor P1.

[0048] S3: Open the chamber door 12 again, place the container that has contained the sludge sample on the tray above the gravity sensor 10 in the sample chamber 8, close the chamber door 12 tightly, process it through the processor 18, and display the recorded mass m1 on the display 19.

[0049] S4: When the air pressure stabilizes after closing the door 12 again, record the value of the air pressure sensor 9 as P2. Start the hydraulic rod 2 through the power drive seat 15. The hydraulic rod 2 pushes the piston 5 to the limit sensor 11. The limit sensor transmits the limit signal to the processor. The processor sends a signal to stop pushing the hydraulic rod. After waiting for a few seconds for the air pressure to stabilize, record the air pressure sensor value as P3.

[0050] Since the volume of the squeezing cylinder 7 from the exhaust port 6 to the limit sensor 11 is known and set to V, the sludge moisture content is calculated according to the following formula:

[0051]

[0052]

[0053] Where ρ s The dry basis density of the sludge is ρ. s = -0.5sin(t / 12π) + 2.6g / cm 3 t represents the month, taking any value from 1 to 12, or, using the sludge true density measurement method described in this invention, several portions of sludge are dried to an absolutely dry state, their true density is measured, and the average value is taken as the sludge dry basis density for the current month; ρ l The density of water is 1 g / cm³. 3 .

[0054] The processor 18 receives and processes signals from the pressure sensor 9, gravity sensor 10, and limit sensor 11, converts the signals into digital signals of mass and pressure, calculates the sludge moisture content according to the calculation formula, and saves and displays the data.

[0055] Example 2:

[0056] The true density of sludge with different moisture contents was measured, and the true density was calculated using the formula provided in this invention. The results are as follows: Figure 3 As shown;

[0057] S1: Open the chamber door 12, place the empty container for holding the sludge sample to be tested on the gravity sensor 10 in the sample chamber 8, close the chamber door tightly, and the gravity sensor 10 and the air pressure sensor 9 return the mass signal m0 and the air pressure signal P0 to the information processor.

[0058] S2: After receiving and recording the mass and pressure signals, the signal processor starts the hydraulic rod. Once the limit sensor 11 detects contact with piston 5, it transmits the signal to the signal processing system, which then controls the hydraulic rod 2 to stop moving. When the air pressure stabilizes, the air pressure sensor 9 returns the air pressure signal P1 to the information processing system.

[0059] S3: Open the chamber door 12, place the container containing the sludge sample on the gravity sensor 10 inside the sample chamber 8, close the chamber door 12, and the gravity sensor 10 and the air pressure sensor return the mass signal m1 and the air pressure signal P2 to the information processing system.

[0060] S4: After receiving and recording the mass and pressure signals, the signal processing system restarts the hydraulic rod. Upon detecting piston contact, the limit sensor transmits a signal to the signal processing system, which then controls the hydraulic rod to stop moving. Once the air pressure stabilizes, the air pressure sensor returns an air pressure signal P3 to the information processing system.

[0061] Since the volume of the extrusion cylinder 7, from the vent hole to the connection point between the extrusion cylinder 7 and the sample chamber 8, is known, it is set to V; the true density of the sludge is calculated according to the following formula:

[0062]

[0063] Calculate the sludge moisture content using the following formula:

[0064]

[0065] Where ρ s The dry basis density of the sludge is ρ. s = -0.5sin(t / 12π) + 2.6g / cm 3 g / cm 3 t represents the month, ranging from 1 to 12. Alternatively, using the sludge true density measurement method described in this invention, several samples of sludge are dried to an absolutely dry state, their true density is measured, and the average value is taken as the sludge dry basis density for the current month; ρ l For the density of water, take 1 g / cm³. 3 .

[0066] The device described above can not only measure the moisture content of sludge, but also the moisture content of other hygroscopic porous materials, provided that the density of the solid dry basis is obtained beforehand.

[0067] Sludge drying represents ideal shrinkage, and its true volume (excluding the volume of internal pores) can be considered as the sum of the volume of the dry sludge and the volume of water within the sludge. Therefore, the relationship between the true density and moisture content of sludge is as follows:

[0068]

[0069] Where ρ s ρ is the dry basis density of the sludge. l ρ is the density of water, and ρ is the true density of sludge.

[0070] The results confirm that the method provided by this invention can accurately reflect the relationship between sludge moisture content and true density. This method uses air removal to eliminate the influence of porosity in the sludge, thereby obtaining the true density of the sludge and calculating its moisture content.

[0071] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and substitutions without departing from the technical principles of the present invention, and these improvements and substitutions are all considered to be within the protection scope of the present invention.

Claims

1. A measurement method of a sludge moisture content detection device based on true density, the detection device comprising a sample chamber, characterized in that, A detection device is installed inside the sample chamber. A compression device is installed on one side of the sample chamber and is mounted inside a support device. The detection device includes a pressure sensor, a gravity sensor, and a limit sensor. The pressure sensor is installed on the side wall of the sample chamber, the gravity sensor is installed at the bottom of the sample chamber, and a sample tray is installed above the gravity sensor. The limit sensor is located at the connection between the sample chamber and the compression device. The compression device includes a power drive base connected to a hydraulic rod, which is connected to a piston. A compression cylinder is installed on one side of the piston. The support device includes a top plate, on which multiple inner and outer support columns are connected respectively. One side of each inner support column is connected to the top plate, and the other side is connected to the compression cylinder. One side of each outer support column is connected to the edge of the top plate, and the other side is connected to the sample chamber. The device also includes an information processing and display device connected to the detection device. The information processing and display device includes a processor and a display. The processor is electrically connected to the pressure sensor, gravity sensor, and limit sensor respectively, and the display is connected to the processor. The measurement method includes the following steps: S1: opening the door of the bin, placing an empty container for containing the sludge sample to be tested on the tray above the gravity sensor in the sample bin, closing the door of the bin, and displaying the recorded mass on the display through the processor m 0; S2: when the air pressure is stable, record the air pressure sensor value as P 0, start the hydraulic rod through the power on the power driven seat, the hydraulic rod until the piston is pushed to the limit sensor, the limit sensor limit signal is transmitted to the processor, the processor transmits a signal to stop pushing the hydraulic rod, wait for a few seconds when the air pressure is stable, record the air pressure sensor value P 1; S3: Open the chamber door again, place the container already filled with sludge sample on the tray above the gravity sensor inside the sample chamber, close the chamber door tightly, process the data through the processor, and display the recorded quality on the monitor. m 1; S4: When the air pressure stabilizes after closing the door again, record the air pressure sensor value as follows: P 2. The hydraulic rod is activated by the power drive unit. Once the hydraulic rod pushes the piston to the limit sensor, the limit sensor transmits a limit signal to the processor. The processor then sends a signal to stop pushing the hydraulic rod. After waiting several seconds for the air pressure to stabilize, the air pressure sensor value is recorded. P 3; Since the volume of the extrusion cylinder from the exhaust port to the limit sensor is known, it is set to... V The sludge moisture content is calculated using the following formula: in ρ s The dry basis density of the sludge is... ρ s = -0.5sin( t / 12 π )+2.6 g / cm 3 , t For the month, the value can be any value from 1 to 12. Alternatively, the true density of sludge can be measured by drying several portions of sludge to an absolutely dry state, measuring their true density and taking the average value as the dry basis density of the sludge for that month. ρ l The density of water is 1 g / cm³. 3 ; The information processing and display device receives sensor signals from the processor and display, converts them into digital signals of mass and pressure, calculates the sludge moisture content according to the embedded calculation formula, and saves and displays the data.

2. The measurement method for sludge moisture content detection device based on true density according to claim 1, characterized in that, The number of inner support columns is 4, and the number of outer support columns is 4. The inner support columns fix the top plate and the extrusion cylinder respectively, and the outer support columns fix the power drive seat and the sample chamber.

3. The measurement method for a sludge moisture content detection device based on true density according to claim 2, characterized in that, The connection between the inner support column and the extrusion cylinder enables the hydraulic rod, piston, and extrusion cylinder to be on the same axis.

4. The measurement method for a sludge moisture content detection device based on true density according to claim 3, characterized in that, The extrusion cylinder has an exhaust port on its side, which is located at the upper end of the extrusion cylinder. The distance between the exhaust port and the left edge of the extrusion cylinder is not less than the thickness of the piston.

5. The measurement method for sludge moisture content detection device based on true density according to claim 1, characterized in that, A through hole is provided between the sample chamber and the detection device to connect the sample chamber and the detection device. A limit sensor is provided on the through hole, and the limit sensor is connected to the through hole through a limit rod. The volume of the extrusion cylinder from the exhaust port to the limit sensor is known.

6. The measurement method for a sludge moisture content detection device based on true density according to claim 1, characterized in that, The sample chamber is equipped with a door at the front end, and a sealing strip is provided on the door. The sample tray is installed on a base column, and a gravity sensor is provided on the base column.

7. The measurement method for sludge moisture content based on a true density detection device according to claim 1, characterized in that, The processor receives and processes signals from the pressure sensor, gravity sensor, and limit sensor, respectively.

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