Water sand separator, separation system and method for evaluating performance thereof

Abstract

The application discloses a water-sand separator, a separation system and a method for evaluating the efficiency of the water-sand separator. The method comprises the following steps: obtaining the path length required for fluid to flow from the inlet to the outlet of the separator, the particle settling velocity, the height difference between the water surface of the inlet pipeline and the downstream pipeline inversion, and the inlet water flow velocity; calculating the first time required for water to flow from the inlet to the outlet of the separator according to the path length and the inlet water flow velocity; calculating the second time required for particles to settle from the water surface of the inlet to the downstream pipeline inversion according to the height difference and the particle settling velocity; and calculating the non-dimensional value of the water-sand separator according to the first time and the second time, wherein the non-dimensional value is the ratio of the first time to the second time. Based on the non-dimensional value, the sediment removal efficiency of the water-sand separator can be determined, and the calculation process is simple and the operation steps are few.

Description

Technical Field

[0001] This invention relates to the field of water conservancy equipment technology, and in particular to water-sand separators, separation systems and their performance evaluation methods. Background Technology

[0002] A water-sand separator is a device used for solid-liquid separation. It is widely used in industrial production and environmental protection. In many processes, it is necessary to separate solid particles or sediments suspended in water from the liquid in order to purify water or recover solid materials.

[0003] Although the water-sand separator has a relatively simple structure, its internal flow field exhibits strong rotating turbulence characteristics, which leads to a certain degree of randomness in the movement and distribution of particles within the flow field. Therefore, the separation and movement of solid particles in the hydraulic swirling field is relatively complex.

[0004] However, the sediment removal efficiency of water-sand separators in related technologies is not easy to measure. Usually, the removal efficiency can only be obtained by measuring the mass and weight of residual particles inside the water-sand separator, which is very inconvenient. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned technical deficiencies and to propose a water-sand separator, a separation system and its performance evaluation method, thereby solving the technical problem that the sediment removal efficiency of water-sand separators is not easy to measure in the prior art.

[0006] To achieve the above-mentioned technical objectives, in a first aspect, the present invention provides a water-sand separator, comprising: a cylindrical vertical shaft, an inlet pipe, and an outlet pipe, wherein the inlet pipe and the outlet pipe are tangentially connected to the vertical shaft, and a flow control device and a sand inlet are provided on the inlet pipe, wherein the flow control device is used to control the inlet flow rate, and the sand inlet is used to add particles to the water-sand separator.

[0007] The water-sand separator provided in this application can measure a series of parameters, including the path length required for fluid to flow from the separator inlet to the outlet, particle settling velocity, height difference between the inlet pipe water surface and the inverted downstream pipe, and inlet water flow velocity, without moving the water-sand separator. Based on these parameters, only simple calculations are needed to obtain the sediment removal efficiency of the water-sand separator. The calculation process is simple, which is beneficial for providing a strong basis for the design process of the water-sand separator and improves the efficiency of sediment removal efficiency detection. It has good application value.

[0008] Secondly, the technical solution of the present invention provides a water-sand separation system, comprising:

[0009] As described in the first aspect, a water-sand separator;

[0010] Water supply tank, used to provide clean water free of particles;

[0011] A water pump is connected to the water supply tank and the flow control device, and the water pump is used to pump clean water from the water supply tank into the inlet pipe;

[0012] A drainage tank is connected to the outlet end of the water outlet pipe. The drainage tank is connected to the water supply tank through a pipe to realize water circulation. A nylon net with a mesh size of 300 or higher is installed in the drainage tank to intercept suspended particles that fail to settle in the vertical shaft and flow out with the runoff.

[0013] According to some embodiments of the present invention, the flow control device is any one of the following: a ball valve, a proportional valve, a butterfly valve, or a speed regulating pump.

[0014] Thirdly, the technical solution of the present invention provides a method for evaluating the performance of a water-sand separator, applicable to the water-sand separation system described in any one of the second aspects, comprising the following steps:

[0015] Obtain the path length required for the fluid to travel from the separator inlet to the outlet, the particle settling velocity, the height difference between the water surface in the inlet pipe and the inverted downstream pipe, and the inlet water flow velocity;

[0016] The first time required for water to travel from the separator inlet to the outlet is calculated based on the path length and the inlet water flow velocity.

[0017] The second time required for the particles to settle from the inlet water surface to the inverted downstream pipeline is calculated based on the height difference and the particle settling velocity.

[0018] The dimensionless value of the water-sand separator is calculated based on the first time and the second time. The dimensionless value is the ratio of the first time to the second time. The sediment removal efficiency of the water-sand separator is evaluated by the dimensionless value.

[0019] According to some embodiments of the present invention, the first time required for water to travel from the separator inlet to the outlet is calculated based on the path length and the inlet water flow velocity, and the calculation formula is as follows:

[0020]

[0021] Where C is the path length and V0 is the inlet water flow velocity;

[0022] The second time required for the particles to settle from the inlet water surface to the downstream inverted pipe is calculated based on the height difference and the particle settling velocity. The calculation formula is as follows:

[0023]

[0024] Where h is the height difference, Vs The particle settling velocity;

[0025] The dimensionless value of the water-sand separator is calculated based on the first time and the second time, and the calculation formula is:

[0026]

[0027] Where T1 is the first time and T2 is the second time.

[0028] According to some embodiments of the present invention, obtaining particle settling velocity includes the following steps:

[0029] The particle diameter, particle density, fluid density, and hydrodynamic viscosity were measured.

[0030] The particle settling velocity was calculated using the following formula:

[0031]

[0032] Where g represents gravitational acceleration, dp represents particle diameter, ρs is particle density, ρw represents fluid density, ν represents fluid dynamic viscosity, and d is the internal diameter of the shaft.

[0033] According to some embodiments of the present invention, the particle diameter is selected from 150 micrometers to 250 micrometers.

[0034] According to some embodiments of the present invention, the diameter of the shaft is selected from 500 mm to 800 mm.

[0035] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0036] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein the abstract drawings are to be completely consistent with one of the drawings in the specification:

[0037] Figure 1 This is a structural diagram of a water-sand separator provided in one embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of a water-sand separation system provided in one embodiment of the present invention;

[0039] Figure 3 A flowchart is provided for a method of evaluating the performance of a water-sand separator according to an embodiment of the present invention;

[0040] Figure 4A calculation diagram illustrating a method for evaluating the performance of a water-sand separator, as provided in one embodiment of the present invention.

[0041] Explanation of reference numerals in the attached diagram: water inlet pipe 101, sand filling port 102, vertical shaft 103, and water outlet pipe 104. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0043] It should be noted that although functional modules are divided in the system diagram and the logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than the module division in the system or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, and the aforementioned figures are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0044] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0045] Reference Figure 1 , Figure 1 This is a structural diagram of a water-sand separator provided in one embodiment of the present invention.

[0046] In one embodiment, the water-sand separator includes: a cylindrical vertical shaft 103, an inlet pipe 101, and an outlet pipe 104. Both the inlet pipe 101 and the outlet pipe 104 are tangentially connected to the vertical shaft 103. A flow control device and a sand inlet 102 are provided on the inlet pipe 101. The flow control device is used to control the inlet flow rate, and the sand inlet 102 is used to add particles to the water-sand separator.

[0047] The water-sand separator provided in this embodiment can measure the path length required for fluid to flow from the separator inlet to the outlet, particle settling velocity, height difference between the inlet pipe water surface and the inverted downstream pipe, and inlet water flow velocity. These parameters can all be measured without moving the water-sand separator. Based on the above parameters, only simple calculations are needed to obtain the sediment removal efficiency of the water-sand separator. The calculation process is simple, which is beneficial to providing a strong basis for the design process of the water-sand separator and improves the efficiency of sediment removal efficiency detection of the water-sand separator. It has good application value.

[0048] Reference Figure 2 , Figure 2 This is a schematic diagram of a water-sand separation system provided in one embodiment of the present invention.

[0049] In one embodiment, the water-sand separation system includes: a water-sand separator, comprising: a cylindrical vertical shaft 103, an inlet pipe 101, and an outlet pipe 104, both of which are tangentially connected to the vertical shaft 103. A flow control device and a sand inlet 102 are provided on the inlet pipe 101. The flow control device controls the inlet flow rate, and the sand inlet 102 adds particles to the water-sand separator. A water supply tank provides clean water free of particles. A water pump is connected to the water supply tank and the flow control device, pumping clean water from the water supply tank into the inlet pipe 101. A drainage tank is connected to the outlet end of the outlet pipe 104, connected to the water supply tank via a pipe to achieve water circulation. A nylon mesh of 300 mesh or finer is provided inside the drainage tank to trap suspended particles that fail to settle in the vertical shaft 103 and flow out with the runoff.

[0050] The flow control device can be any of the following: ball valve, proportional valve, butterfly valve, or speed control pump.

[0051] Reference Figure 3 and Figure 4 , Figure 3 A flowchart is provided for a method of evaluating the performance of a water-sand separator according to an embodiment of the present invention; Figure 4 This diagram illustrates a calculation method for evaluating the performance of a water-sand separator according to an embodiment of the present invention. The method for evaluating the performance of the water-sand separator includes, but is not limited to, steps S110 to S140.

[0052] Step S110: Obtain the path length required for the fluid to flow from the separator inlet to the outlet, the particle settling velocity, the height difference between the water surface in the inlet pipe and the inverted downstream pipe, and the inlet water flow velocity.

[0053] Step S120: Calculate the first time required for water to travel from the separator inlet to the outlet based on the path length and the inlet water flow velocity;

[0054] Step S130: Calculate the second time required for the particles to settle from the inlet water surface to the inverted downstream pipe based on the height difference and particle settling velocity.

[0055] Step S140: Calculate the dimensionless value of the water-sand separator based on the first time and the second time. The dimensionless value is the ratio of the first time to the second time. Evaluate the sediment removal efficiency of the water-sand separator using the dimensionless value.

[0056] In one embodiment, the efficiency evaluation method for a water-sand separator includes the following steps: obtaining the path length required for fluid to travel from the separator inlet to the outlet, particle settling velocity, height difference between the water surface in the inlet pipe and the inverted downstream pipe, and inlet flow velocity; calculating the first time required for water to travel from the separator inlet to the outlet based on the path length and inlet flow velocity; calculating the second time required for particles to settle from the inlet water surface to the inverted downstream pipe based on the height difference and particle settling velocity; calculating the dimensionless value of the water-sand separator based on the first and second times, wherein the dimensionless value is the ratio of the first and second times, and evaluating the sediment removal efficiency of the water-sand separator using the dimensionless value.

[0057] In a specific experiment, for particles with a diameter of 150 micrometers, the settling velocity Vs was 0.012 m / s. The J-number calculated according to the equation was 0.36, which is less than 1, and the actual measured particle removal rate was 65.80%. For particles with a diameter of 250 micrometers, the settling velocity was 0.027 m / s, the J-number increased to 0.83, and the corresponding measured removal rate was 98.60%. Therefore, as the J-value increases, the performance of the water-sand separator also improves.

[0058] The initial time required for water to travel from the separator inlet to the outlet is calculated based on the path length and the inlet water flow velocity. The calculation formula is as follows:

[0059]

[0060] Where C is the path length and V0 is the inlet water flow velocity;

[0061] The second time required for particles to settle from the inlet water surface to the downstream inverted pipe is calculated based on the height difference and particle settling velocity. The calculation formula is as follows:

[0062]

[0063] Where h is the height difference, V s This refers to the particle settling velocity;

[0064] The dimensionless value of the water-sand separator is calculated based on the first and second time intervals, and the calculation formula is:

[0065]

[0066] Where T1 is the first time and T2 is the second time.

[0067] Overall, evaluating the sediment removal efficiency of a water-sand separator is crucial for assessing the operation of a stormwater system. A dimensionless value J is defined as:

[0068]

[0069] Generally, evaluating the sediment removal efficiency of a water-sand separator is crucial for assessing the operation of a stormwater system. A dimensionless value J is defined as: where C is the path length required for the fluid to travel from the separator inlet to the outlet, such as... Figure 4 As shown in C50; Vs is the calculated particle settling velocity; h is the height difference between the water surface in the inlet pipe and the inverted downstream pipe; V0 is the inlet water flow velocity.

[0070] The physical meaning of J is the ratio of the time required for water to travel from the separator inlet to the outlet to the time required for particles to settle from the inlet water surface to the inverted position in the downstream pipe. Ideally, for flow conditions where J > 1, the time for particles to settle to the inverted position in the downstream pipe is less than the time for water to travel from the inlet to the outlet, thus corresponding to better removal efficiency. However, in actual separators, due to the complex swirling flow field, the interaction between water flow and particles can be complex and difficult to predict, and the J value does not always need to be greater than 1 to achieve a satisfactory sediment removal rate.

[0071] In one test case, a separator with a diameter of 500 mm (corresponding to C = 0.785 m) was tested in a 150 mm diameter inlet pipe at a flow rate of 3 L / s, resulting in a half-full pipe flow of V0 = 0.34 m / s and h = 0.075 m. For particles with a diameter of 150 μm, the settling velocity Vs was 0.012 m / s. In this case, the J-number calculated according to the equation was 0.36, less than 1, and the actual measured particle removal rate was 65.80%. For particles with a diameter of 250 μm, the settling velocity was 0.027 m / s, the J-number increased to 0.83, and the corresponding measured removal rate was 98.60%. Therefore, as the J-value increases, the performance of the water-sand separator improves.

[0072] Regarding the separator size optimization case, when the separator diameter was increased to 1.2 times and 1.5 times the original design, under the same flow conditions, for particles with a diameter of 150 micrometers, the J number increased to 0.43 and 0.54, respectively, corresponding to removal rates of approximately 80% and 90%. For larger particles with a diameter of 250 micrometers, the J number increased to 1.00 and 1.25, respectively, corresponding to removal rates reaching approximately 100%. For modifications to the separator height, since the physical parameters in the equations were not affected, the J number remained consistent with the original design, while the measured removal efficiency only slightly improved, from 65.8% to 70% for particles with diameters of 150 micrometers and from 98.6% to 99%, respectively. The trends in sediment removal rate and J value indicate that in the specific design of this study, when J = 0.8, the removal rate already reached 99%, and further increasing J to greater than 1 did not significantly improve efficiency. In the case of varying separator height, the improvement primarily comes from changes in the flow field (i.e., potentially longer hydraulic residence time) rather than the mechanisms described in the equations.

[0073] For engineering applications, given flow conditions, a water-sand separator can be designed or optimized. The system's design flow rate and depth can determine the inlet velocity V0 and elevation variation h. Local particle size distribution can be measured, and Vs can be determined using the median diameter. After completing the preliminary design, C can be determined, and thus the design J-number can be calculated. The goal of the design is to adjust the design parameters to achieve a higher J-number while meeting design requirements such as footprint, budget, construction, and accessibility.

[0074] Further, the particle settling velocity is obtained, including the following steps:

[0075] The particle diameter, particle density, fluid density, and hydrodynamic viscosity were measured.

[0076] The particle settling velocity was calculated using the following formula:

[0077]

[0078] Where g represents gravitational acceleration, dp represents particle diameter, ρs is particle density, ρw represents fluid density, ν represents fluid dynamic viscosity, and d is the internal diameter of the shaft.

[0079] The particle diameter can be selected from 150 micrometers to 250 micrometers.

[0080] The diameter of the shaft can be selected from 500 mm to 800 mm.

[0081] Those skilled in the art will understand that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information transmission medium.

[0082] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of the present invention.

[0083] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for evaluating the performance of a water-sand separator, characterized in that, Includes the following steps: Obtain the path length required for the fluid to travel from the separator inlet to the outlet, the particle settling velocity, the height difference between the water surface in the inlet pipe and the inverted downstream pipe, and the inlet water flow velocity; The first time required for water to travel from the separator inlet to the outlet is calculated based on the path length and the inlet water flow velocity. The second time required for the particles to settle from the inlet water surface to the downstream inverted pipe is calculated based on the height difference and the particle settling velocity. The dimensionless value of the water-sand separator is calculated based on the first time and the second time. The dimensionless value is the ratio of the first time to the second time. The sediment removal efficiency of the water-sand separator is evaluated by the dimensionless value.

2. The method for evaluating the efficiency of a water-sand separator according to claim 1, characterized in that, The first time required for water to travel from the separator inlet to the outlet is calculated based on the path length and the inlet water flow velocity, using the following formula: Where C is the path length and V0 is the inlet water flow velocity; The second time required for the particles to settle from the inlet water surface to the downstream inverted pipe is calculated based on the height difference and the particle settling velocity. The calculation formula is as follows: Where h is the height difference, V s The particle settling velocity; The dimensionless value of the water-sand separator is calculated based on the first time and the second time, and the calculation formula is: Where T1 is the first time and T2 is the second time.

3. The method for evaluating the efficiency of a water-sand separator according to claim 2, characterized in that, To obtain particle settling velocity, the following steps are included: The particle diameter, particle density, fluid density, and fluid dynamic viscosity were measured. The particle settling velocity was calculated using the following formula: Where g represents the acceleration due to gravity. Indicates particle diameter, Particle density, ν represents the fluid density, ν represents the fluid dynamic viscosity, and d is the internal diameter of the shaft.

4. The method for evaluating the performance of a water-sand separator according to claim 3, characterized in that, The particle diameter is selected from 150 micrometers to 250 micrometers.

5. The method for evaluating the performance of a water-sand separator according to claim 3, characterized in that, The internal diameter of the shaft can be selected from 500 mm to 800 mm.

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