Solid sample density screening equipment

Abstract

The invention belongs to the technical field of density screening, and discloses solid sample density screening equipment, which comprises a test liquid and a container for accommodating the test liquid, and the density of the test liquid determines the floating and sinking states of a solid sample in the test liquid; the wall of the container is provided with a temperature sensor and a sensor used for measuring the liquid level of the container in the depth direction, and the temperature sensor is used for measuring the temperature of the test liquid. According to the method, density screening can be rapidly carried out on the solid samples, the detection efficiency is greatly improved, the requirement for real-time rapid detection on a large-scale production line can be met, compared with a traditional detection method, the detection time can be shortened by several times or even dozens of times, specifically, the solid samples are rapidly and accurately screened through the buoyancy law, and the detection efficiency is greatly improved. The solid sample with the density smaller than that of the testing liquid floats upwards, and the solid sample with the density larger than that of the testing liquid sinks.

Description

Technical Field

[0001] This invention belongs to the field of density screening technology, and specifically relates to a solid sample density screening device. Background Technology

[0002] Polyethylene (PE), as the most produced general-purpose synthetic resin, mainly includes low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE). Among them, the density of low-density polyethylene (LDPE) is generally between 0.910 and 0.940 g / cm³. 3 It possesses excellent flexibility, extensibility, electrical insulation, and transparency, and is widely used in film products, injection molded products, medical devices, pharmaceutical and food packaging materials, blow-molded hollow products, and other fields. High-density polyethylene (HDPE) typically has a density ranging from 0.941 to 0.965 g / cm³. 3 It has the advantages of high crystallinity, non-polarity, heat resistance, cold resistance, stability and rigidity. It is widely used in plastic products, packaging, electronics, daily necessities, automobiles and other fields. It is often used as a material for decorative panels, blinds, wires and cables, drainage pipes and other materials.

[0003] In actual production and application, it is necessary to quickly and accurately screen the density of polyethylene to distinguish between low-density polyethylene (LDPE) and high-density polyethylene (HDPE). Currently available density testing methods and equipment suffer from slow testing speed, complex operation, and high cost, making it difficult to meet the demand for rapid differentiation between LDPE and HDPE in large-scale production.

[0004] In addition, in practical work, many samples require density screening, including not only polyethylene products but also graphite products. For example, in artificial graphite products, such as high-purity graphite, a purity greater than 99.9%, a flexural strength greater than 30 MPa, and a density greater than 1.73 g / cm³ are required. 3 When screening for high-density, high-efficiency, and high-value-added graphite, it is necessary to determine whether its density is greater than 1.73 g / cm³. 3 If its density is less than this index, it is determined that it does not belong to high-density graphite.

[0005] Therefore, it is necessary to develop a device that can quickly and accurately screen the density of solid samples, such as a device for screening the density of low-density polyethylene (LDPE) and high-density polyethylene (HDPE), and a device for screening the density of graphite products. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a solid sample density screening device.

[0007] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0008] A solid sample density screening device includes a test liquid and a container for containing the test liquid, wherein the density of the test liquid determines the floating and sinking state of the solid sample in the test liquid;

[0009] The container wall is equipped with a temperature sensor and a sensor for measuring the liquid level in the depth direction of the container. The temperature sensor measures the temperature of the test liquid.

[0010] Taking polyethylene products as an example, when performing density screening, this invention utilizes the law of buoyancy to quickly and accurately screen low-density polyethylene and high-density polyethylene. The density of the test liquid is greater than that of low-density polyethylene but less than that of high-density polyethylene, which can cause low-density polyethylene to float and high-density polyethylene to sink.

[0011] Under the influence of buoyancy, low-density polyethylene and high-density polyethylene are automatically separated.

[0012] The sensor has the function of indirectly identifying the discharge object. Specifically, it is used to detect how much test liquid has been discharged, thereby indirectly identifying the current discharge object. After the polyethylene is naturally filtered by buoyancy, it still needs to be discharged and collected. The high-density polyethylene at the bottom is discharged first. During discharge, the high-density polyethylene is mixed with the test liquid and flows out together. The function of the sensor is to detect how much test liquid has flowed out. When the test liquid discharges to the set value, it can be considered that the high-density polyethylene at the bottom has been discharged. What is discharged next is a mixture of low-density polyethylene and test liquid.

[0013] The purpose of a temperature sensor is to monitor the temperature of the test liquid. Because the density of a liquid changes with temperature, if the temperature change is too large, the liquid density will change, and the purpose of buoyancy screening will not be achieved. Therefore, the temperature sensor can monitor the temperature of the test liquid to determine whether the current screening conditions are met and whether the temperature of the test liquid needs to be adjusted.

[0014] Taking graphite products as an example, the screening principle is the same as that for polyethylene products. Both methods determine the relationship between the density of the solid and the density of the test liquid by observing whether the solid floats or sinks in the test liquid. If the graphite sinks relative to the test liquid, it means that the density of the graphite is greater than that of the test liquid. If the graphite floats relative to the test liquid, it means that the density of the graphite is less than that of the test liquid. Since the screening process is the same as that for polyethylene, it will not be described in detail here.

[0015] In some optional instances, when performing density screening on polyethylene, the density of the test liquid is greater than 0.940 g / cm³.3 And less than 0.941 g / cm 3 .

[0016] In some optional instances, when performing density screening on graphite, the density of the test liquid is equal to 1.73 g / cm³. 3 .

[0017] The beneficial effects of this invention are:

[0018] 1. It can quickly screen the density of solid samples, greatly improving the detection efficiency and meeting the needs of real-time rapid detection on large-scale production lines. Compared with traditional detection methods, the detection time can be shortened by several times or even tens of times. Taking polyethylene products as an example, specifically, the law of buoyancy is used to quickly and accurately screen low-density polyethylene and high-density polyethylene. The density of the test liquid is greater than the density of low-density polyethylene but less than the density of high-density polyethylene, which can make low-density polyethylene float and high-density polyethylene sink.

[0019] 2. The operation is simple, requiring no complicated sample pretreatment or professional operating skills, which reduces the labor intensity of operators and the requirements for their professional level.

[0020] 3. High accuracy and low cost: The equipment has a relatively simple structure, eliminating the need for expensive testing instruments and complex testing reagents, thus reducing manufacturing and operating costs. Furthermore, its fast testing speed and ease of operation reduce labor and time costs. Attached Figure Description

[0021] The present invention can be further illustrated by the non-limiting embodiments given in the accompanying drawings;

[0022] Figure 1 This is a schematic diagram of the first structure according to an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the second structure according to an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the container structure in an embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of the structure of the thermostatic cover in an embodiment of the present invention;

[0026] The symbols for the main components are explained below:

[0027] 1. Container; 11. Transition chamber; 12. Sedimentation chamber; 13. Liquid level change amplification chamber; 14. Liquid inlet; 15. Feed inlet; 16. Second mounting hole; 17. Ring; 181. First retainer; 182. Second retainer; 183. First mounting hole; 19. Drainage port;

[0028] 2. Contact-type liquid level sensor;

[0029] 3. Temperature sensor;

[0030] 4. Three-way ball valve;

[0031] 5. First discharge pipe;

[0032] 6. Thermostatic cover; 61. Snap ring; 62. Vent; 63. Air inlet; 64. Exhaust outlet; 65. Placement space;

[0033] 7. Second discharge pipe;

[0034] 81. First non-contact liquid level sensor; 82. Second non-contact liquid level sensor. Detailed Implementation

[0035] The technical solutions of the present invention will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary, and should not be construed as limiting the implementation methods or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0036] Example 1

[0037] like Figure 1 As shown, this embodiment provides a solid sample density screening device, including a test liquid and a container 1 for containing the test liquid. The density of the test liquid determines the floating and sinking state of the solid sample in the test liquid.

[0038] Temperature sensor 3 and a sensor for measuring the liquid level in the depth direction of container 1 are installed on the wall of container 1. Temperature sensor 3 measures the temperature of the test liquid.

[0039] In this embodiment, taking polyethylene as an example, density screening utilizes the law of buoyancy to quickly and accurately screen low-density polyethylene (LDPE) and high-density polyethylene (HDPE). The density of the testing liquid is greater than that of LPE but less than that of HDPE, causing LPE to float and HDPE to sink. During polyethylene density screening, the density of the testing liquid is greater than 0.940 g / cm³. 3 And less than 0.941 g / cm 3 ;

[0040] Under the influence of buoyancy, low-density polyethylene and high-density polyethylene are automatically separated.

[0041] The sensor has the function of indirectly identifying objects. Specifically, it can be used to detect how much test liquid has been discharged and thus indirectly identify the current discharge object. After the polyethylene is naturally filtered by buoyancy, it still needs to be discharged and collected. The high-density polyethylene at the bottom is discharged first. During discharge, the high-density polyethylene is mixed with the test liquid and flows out together. The function of the sensor is to detect how much test liquid has been discharged. When the test liquid is discharged to the set value, it can be considered that the high-density polyethylene at the bottom has been discharged. What is discharged next is a mixture of low-density polyethylene and test liquid.

[0042] The function of temperature sensor 3 is to monitor the temperature of the test liquid. Because the density of the liquid changes with temperature, if the temperature change is too large, the liquid density will change and the purpose of buoyancy screening will not be achieved. Therefore, the monitoring of the temperature of the test liquid by temperature sensor 3 can determine whether the current screening conditions are met and whether the temperature of the test liquid needs to be adjusted. A first mounting hole 183 for installing temperature sensor 3 is provided on the wall of container 1, and the hole is sealed.

[0043] Taking graphite products as an example, the screening principle is the same as that for polyethylene products. Both methods determine the relationship between the solid's density and the test liquid's density by observing whether the solid floats or sinks. If the graphite sinks relative to the test liquid, it indicates that the graphite's density is greater than the test liquid's density; if the graphite floats, it indicates that the graphite's density is less than the test liquid's density. Since the screening process is the same as for polyethylene, it will not be elaborated further here. When screening graphite products, the density of the test liquid is determined to be 1.73 g / cm³. 3 .

[0044] Example 2

[0045] like Figure 3 As shown, this embodiment provides a solid sample density screening device. The difference from Embodiment 1 is that the container 1 forms three cavities inside by the contraction of the container wall, including a liquid level change amplification cavity 13 at the top, a transition cavity 11 in the middle, and a sedimentation cavity 12 at the bottom. The liquid level change amplification cavity 13 is smaller at the top and larger at the bottom, the cross-section of the transition cavity 11 remains unchanged, and the sedimentation cavity 12 is larger at the top and smaller at the bottom.

[0046] In this embodiment, polyethylene is used as an example for density screening. The sedimentation chamber 12, which is larger at the top and smaller at the bottom, can play a gathering role, making it easy for polyethylene to be discharged without any residue. The liquid level change amplification chamber 13 becomes smaller at the top, which can more obviously reflect the change in liquid level. The transition chamber in the middle leaves a certain space between the top and bottom of the test solution, so as to avoid the low-density polyethylene and high-density polyethylene after buoyancy screening being too close together.

[0047] Example 3

[0048] like Figure 1 As shown, this embodiment provides a solid sample density screening device. The difference from embodiment 2 is that the sensor is a contact liquid level sensor 2. The test end of the contact liquid level sensor 2 is located inside the container 1 and covers the liquid level change range of the liquid level change amplification cavity 13.

[0049] In this embodiment, a polyethylene product is used as an example for density screening. The function of the contact liquid level sensor 2 is to detect whether polyethylene has been added to the container 1. Because the addition of polyethylene will cause the liquid level of the test liquid to rise, the test end of the contact liquid level sensor 2 covers the liquid level change range of the liquid level change amplification cavity 13 in order to ensure that the change in liquid level can be detected by the contact liquid level sensor 2.

[0050] In some optional instances, the test end of the contact level sensor 2 continues to cover the transition cavity 11 downwards, which can better expand the level detection range. The top of the container 1 is provided with a second mounting hole 16 for mounting the contact level sensor 2.

[0051] Example 4

[0052] like Figure 2 As shown, this embodiment provides a solid sample density screening device. The difference from embodiment 2 is that the sensor is a first non-contact liquid level sensor 81 and a second non-contact liquid level sensor 82. Both the first non-contact liquid level sensor 81 and the second non-contact liquid level sensor 82 are located on the outer wall of the transition cavity 11 of container 1 and there is a difference in installation height.

[0053] The outer wall of container 1 is provided with a first holder 181 for placing a first non-contact liquid level sensor 81 and a second holder 182 for placing a second non-contact liquid level sensor 82.

[0054] In this embodiment, the first non-contact liquid level sensor 81 and the second non-contact liquid level sensor 82 are easy to install and maintain. Simply insert the first non-contact liquid level sensor 81 into the first card holder 181 and the second non-contact liquid level sensor 82 into the second card holder 182.

[0055] Taking polyethylene products as an example for density screening, assuming the first non-contact liquid level sensor 81 is on top and the second non-contact liquid level sensor 82 is on the bottom, when adding test liquid to container 1, the liquid level should be higher than the first non-contact liquid level sensor 81, and the first non-contact liquid level sensor 81 should be triggered. When discharging the high-density polyethylene at the bottom, the liquid level should drop to the second non-contact liquid level sensor 82 as a signal that the high-density polyethylene has been completely discharged. At this time, if enough test liquid has been discharged, it can be determined that the high-density polyethylene has been completely discharged.

[0056] Example 5

[0057] like Figure 1 As shown, this embodiment provides a solid sample density screening device. The difference from embodiment 2 is that the bottom of container 1 is provided with a drain port 19. A three-way ball valve 4 for controlling the on / off state and flow direction is installed at the drain port 19. The second port of the three-way ball valve 4 is connected to a first drain pipe 5 for discharging low-density products, and the third port of the three-way ball valve 4 is connected to a second drain pipe 7 for discharging high-density products.

[0058] In this embodiment, polyethylene products are used as an example for density screening. The three-way ball valve 4 has two functions. The first function is to cut off the passage. During the buoyancy screening process, the three-way ball valve 4 cuts off the passage for the test liquid to flow downward. The second function is to select the passage. Because low-density polyethylene and high-density polyethylene need to be discharged separately after screening and separation, a first discharge pipe 5 is set up to discharge low-density polyethylene and a second discharge pipe 7 is set up to discharge high-density polyethylene. The three-way ball valve 4 can select whether the discharge port 19 is connected to the first discharge pipe 5 or the second discharge pipe 7 by rotating the internal ball.

[0059] In some optional examples, the top of container 1 is provided with a liquid inlet 14 and a feeding inlet 15, which are used to add test liquid and to add polyethylene, respectively. The polyethylene at the feeding inlet 15 can be added by automated equipment. For example, polyethylene is stored in a hopper, and a vibrating feeder is installed at the bottom of the hopper. The outlet of the vibrating feeder is connected to a feeding pipe, which leads directly to the feeding inlet 15. The vibration of the vibrating feeder causes the polyethylene particles in the hopper to enter the conveying pipe evenly, and the conveying pipe transports the polyethylene particles to container 1.

[0060] Example 6

[0061] like Figure 1 , 2As shown in Figure 4, this embodiment provides a solid sample density screening device. The difference from Embodiment 1 is that the container 1 is equipped with a constant temperature cover 6 for sealing itself. The outer wall of the container 1 is provided with two rings 17, and a groove is formed between the two rings 17 to limit the constant temperature cover 6. The inner wall of the constant temperature cover 6 is provided with a retaining ring 61 corresponding to the groove. The retaining ring 61 is provided with an air passage hole 62. The constant temperature cover 6 is provided with an air inlet hole 63 and an exhaust hole 64.

[0062] In this embodiment, since temperature changes will alter the density of the test liquid, a constant temperature cover 6 is installed on the outside of the container 1 to reduce the impact of environmental factors on the test liquid inside the container 1. The constant temperature cover 6 is filled with a constant temperature gas, which enters through the air inlet 63 and exits through the exhaust 64. The constant temperature gas avoids the spatial obstruction of the retaining ring 61 by passing through the air passage 62 on the retaining ring 61. In terms of installation, the constant temperature cover 6 is inserted into the retaining groove by the retaining ring 61 to achieve positioning. The final fixing method is selected according to the actual situation, such as bolt fixing.

[0063] Example 7

[0064] like Figure 4 As shown, this embodiment provides a solid sample density screening device. The difference from embodiment 1 is that the constant temperature cover 6 is formed by two sub-units joined together. The lower end face of the constant temperature cover 6 is concave to form a placement space 65, and the air inlet 63 is located on the side of the constant temperature cover 6.

[0065] In this embodiment, the two sub-units must be close together and inserted into the slot to achieve installation. The two sub-units also reduce the manufacturing difficulty. If the whole unit is processed, a blank needs to be formed in one step. In addition, the thermostatic cover 6 can also serve as a support. The lower end face of the thermostatic cover 6 is concave, and the resulting placement space 65 can be used to accommodate various valve devices connected to the container 1, avoiding the valve devices from protruding directly and making it impossible to place the entire thermostatic cover 6 and container 1. The air inlet 63 is located on the side of the thermostatic cover 6 to avoid the presence of structures on the lower end face of the thermostatic cover 6 that would affect placement.

[0066] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A solid sample density screening device, characterized in that: Includes a test liquid and a container (1) for containing the test liquid, wherein the density of the test liquid determines the floating and sinking state of the solid sample in the test liquid; A temperature sensor (3) and a sensor for measuring the liquid level in the depth direction of the container (1) are installed on the wall of the container (1). The temperature sensor (3) measures the temperature of the test liquid.

2. The solid sample density screening device according to claim 1, characterized in that: The container (1) forms three cavities inside by the contraction of the container wall, including a liquid level change amplification cavity (13) at the top, a transition cavity (11) in the middle, and a sedimentation cavity (12) at the bottom. The liquid level change amplification cavity (13) is smaller at the top and larger at the bottom. The cross-section of the transition cavity (11) remains unchanged. The sedimentation cavity (12) is larger at the top and smaller at the bottom.

3. The solid sample density screening device according to claim 2, characterized in that: The sensor is a contact liquid level sensor (2), and the test end of the contact liquid level sensor (2) is located inside the container (1) and covers the liquid level change range of the liquid level change amplification cavity (13).

4. A solid sample density screening device according to claim 2, characterized in that: The sensors are a first non-contact liquid level sensor (81) and a second non-contact liquid level sensor (82). Both the first non-contact liquid level sensor (81) and the second non-contact liquid level sensor (82) are located on the outer wall of the transition cavity (11) of the container (1) and there is a difference in installation height.

5. A solid sample density screening device according to claim 4, characterized in that: The outer wall of the container (1) is provided with a first holder (181) for placing a first non-contact liquid level sensor (81) and a second holder (182) for placing a second non-contact liquid level sensor (82).

6. A solid sample density screening device according to claim 2, characterized in that: The container (1) has a drain port (19) at the bottom. A three-way ball valve (4) is installed at the drain port (19) to control the on / off state and flow direction. The second port of the three-way ball valve (4) is connected to a first drain pipe (5) for discharging low-density products, and the third port of the three-way ball valve (4) is connected to a second drain pipe (7) for discharging high-density products.

7. A solid sample density screening device according to claim 2, characterized in that: The container (1) is provided with a liquid inlet (14) and a feeding inlet (15) at the top.

8. A solid sample density screening device according to claim 1, characterized in that: The container (1) is fitted with a thermostatic cover (6) for sealing itself. The outer wall of the container (1) is provided with two rings (17). A groove is formed between the two rings (17) to limit the thermostatic cover (6). The inner wall of the thermostatic cover (6) is provided with a retaining ring (61) corresponding to the groove. The retaining ring (61) is provided with an air passage hole (62). The thermostatic cover (6) is provided with an air inlet hole (63) and an air outlet hole (64).

9. A solid sample density screening device according to claim 8, characterized in that: The thermostatic cover (6) is formed by the joining of two sub-units.

10. A solid sample density screening device according to claim 8, characterized in that: The lower end face of the thermostatic cover (6) is concave to form a placement space (65), and the air inlet (63) is located on the side of the thermostatic cover (6).

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