Integrated device and method for comprehensive evaluation and determination of filtration performance of filter media in filter pools

Abstract

The present invention discloses an integrated device and method for comprehensive evaluation and determination of the filtration performance of filter media in a filter pool. The integrated device includes a box structure, in which water inlet and outlet, filtration, backwashing, pressure difference measuring tubes, and PLC control systems are arranged; the device adopts a water pump for water inlet, and the water inlet pressure adjustment range is wide, which can achieve a pressure drop difference of the filter layer equal to its thickness within an appropriate particle size range; when the filtration rate is too large, the permeability coefficient can be analyzed by fitting the change curve of the pressure drop difference and instantaneous filtration rate twice or more. The filtration system can set a constant filtration rate and turbidity (suspended matter), and then measure the turbidity (suspended matter) and head loss after running for a certain period of time, and analyze its filtration performance according to the index system. The filter column inlet and outlet interfaces of the device of the present invention are arranged with equal spacing and equal size, the measuring tube can be disassembled and increased, and there is no need to replace the filter media. It can be backwashed with air and water and can be moved in an integrated manner, which facilitates the analysis of filter layers of different heights in the filter column and the switching of the measurement mode.

Description

Technical Field

[0001] The present invention belongs to the technical field of filtration performance determination, and in particular relates to an integrated device and method for comprehensive evaluation and determination of filtration performance of filter media in a filter pool. Background Art

[0002] The permeability coefficient (K) comprehensively reflects the permeability of a filter layer, and its precise determination is crucial for permeability calculations. The permeability coefficient (K) is significantly affected by numerous factors, primarily the shape, size, and heterogeneity coefficient of the filter media particles, as well as the viscosity of the water. Establishing a precise theoretical formula for calculating the permeability coefficient (K) is difficult. Currently, the instruments and test methods used to determine the permeability coefficient (K) in laboratories can be broadly categorized as the "constant head method."

[0003] The constant head test method maintains a constant head throughout the test, thereby maintaining a constant head difference. During the test, a saturated sample with a cross-section of A and a length of L is placed in a transparent plastic cylinder. The water valve is opened, allowing water to flow through the sample from top to bottom and out of the outlet. When the head difference △h and the seepage flow rate Q stabilize, the volume of water V flowing through the sample within a specific time t is measured. When the Reynolds number Re of the water flow in the filter tank is less than 10, it is a low-speed flow and conforms to Darcy's law. The one-dimensional Darcy seepage formula is as follows:

[0004]

[0005] Where: V-surface filtration velocity (m / h); Q-flow rate (m 3 / h); A-filter cross-sectional area (m 2 ); K - permeability coefficient; ΔH - pressure drop across the filter layer, i.e., the height difference across the piezometer (m); ΔL - measured filter layer height, i.e., the distance between the piezometer connections (m). In the above formula, when ΔH = ΔL, the surface filtration velocity corresponding to K is the permeability coefficient.

[0006] Relevant research at home and abroad shows that the growth rate of head loss, the length of filtration cycle, the constant filtration rate, and the removal rate of suspended impurities such as soil, silt, fine organic matter, inorganic matter, and plankton can all be used as key factors in evaluating the filtration performance of the filter bed.

[0007] MBGamet et al. used the ratio of the periodic water production per unit filter area to the head loss at the end of filtration to evaluate the filtration performance. The formula is as follows:

[0008]

[0009] Where: V h -Constant filtration rate, m / h; T-running time, h; H t- Head loss at the end of filtration, m. KJIves added the influence of water quality to the FPI evaluation index proposed by MBGamet et al. The formula is as follows:

[0010]

[0011] Where: C0-average influent turbidity; C e -Average influent turbidity.

[0012] CDBisker et al. proposed the following filtration performance evaluation indicators:

[0013]

[0014] The ratio of the residual head introduced by TDLekkas ΔH t and the excess turbidity ratio ΔC at the calculation point t , the formula is as follows:

[0015]

[0016] Where ΔH t That is, the difference between the limit head loss and the head loss during calculation (H lim -H t ) and the limit head loss H lim The ratio of ΔC t That is, the allowable limit turbidity C lim Subtract the effluent turbidity C during calculation e The difference between the limit turbidity C lim ratio.

[0017] Jing Youhai et al. studied the effect of increasing the filter layer thickness L on the filtration performance, JC index, and the formula is as follows:

[0018]

[0019] Where L is the filter layer thickness.

[0020] In the above formula 2-7, K, ΔH, ΔL, V h , T, H t , C0, C e , ΔH t , ΔC t, L are both the main factors for evaluating the permeability coefficient and filtration performance of filter media. Currently, the test devices involved in the majority of relevant literature research and the market have the following main problems: the filtration rate using normal water pressure head test is too low, and the filter media particle size range for permeability coefficient test is small; the inlet and outlet joint sizes and layer heights are not standardized, the water flow direction of the test filter layer is single and the number of layers is too small; the components of the test equipment have limited versatility and are scattered in layout; there is no backwash function, and the filter media needs to be frequently replaced and cleaned; there is a lack of automated online measurement instruments.

[0021] In summary, there is an urgent need to provide an integrated device and method for comprehensive evaluation and determination of filtration performance of filter media in filter beds to overcome the shortcomings in current practical applications. Summary of the Invention

[0022] In view of the above situation, in order to overcome the defects of the prior art, the present invention provides an integrated device and method for comprehensive evaluation and determination of filtration performance of filter media in a filter pool, which effectively solves the problems in the above background technology.

[0023] To achieve the above-mentioned object, the present invention provides the following technical solution: an integrated device for comprehensive evaluation and determination of filtration performance of filter media in a filter tank, comprising a box structure, the box structure comprising a main frame structure, a box door, a slide rail, and a tool cabinet, the box structure also being provided with a water inlet and outlet system, a filtration system, a backwash system, a pressure differential measuring pipe system, and a PLC control system;

[0024] The water inlet and outlet system includes a water inlet pump, a hose and a drawer-type water tank. Two groups of drawer-type water tanks are arranged in the main frame structure. The filtration system includes a transparent filter column and pyrite particles, a supporting layer and a filter cap arranged in sequence in the transparent filter column, and a sealing cover is also provided on the top of the transparent filter column. The differential pressure measuring tube system includes a glass scale tube group, which is arranged on the door panel of the box door, and there are multiple groups of glass scale tube groups. The multiple groups of glass scale tube groups are respectively connected to the transparent filter column through metal hoses. The water inlet pump and the transparent filter column and the water inlet pump and the drawer-type water tank are all connected through pipes. A hose is also provided between one group of pipes and the upper drawer-type water tank.

[0025] Preferably, a second valve assembly is further provided on the pipeline where the water inlet pump is located, and the second valve assembly includes valve A, valve B, valve C, valve D, valve E and valve F;

[0026] The pipeline where the water inlet pump is located is also provided with a turbidity monitor A, a flow meter A, a flow meter B and a turbidity monitor B.

[0027] Preferably, the metal hose is further provided with a first valve assembly, which includes valve G, valve H, valve I and valve J, and valve G, valve H, valve I and valve J are respectively provided on the metal hose.

[0028] Preferably, the door panel is further provided with a movable buckle for fixing the glass scale tube set, the glass scale tube set includes a glass scale tube A and a glass scale tube B, and the glass scale tube A and the glass scale tube B are spliced by a sealing rubber sleeve.

[0029] Preferably, the drawer-type water tank is further provided with a handle, and the bottom of the drawer-type water tank is provided with rollers for use with slide rails.

[0030] Preferably, the backwash system comprises a backwash air compressor and a backwash water pump, and the backwash air compressor and the backwash water pump are both connected to the transparent filter column and the drawer-type water tank through pipelines.

[0031] Preferably, valves K, L, M and N are further provided on the pipeline where the backwash air compressor and the backwash water pump are located.

[0032] The method for comprehensively evaluating and measuring the filtration performance of filter media in a filter pool adopts the above-mentioned integrated device for comprehensively evaluating and measuring the filtration performance of filter media in a filter pool, and is characterized in that the method comprises the following steps:

[0033] During the upward flow test: open valves A, D, and F, and close the other valves. The water inlet pump pumps water from the raw water tank to the transparent filter column. The water flows from bottom to top, passes through the filter material layer, and then flows to the clean water tank through the pipe where valve F is located. During water backwashing, open valves L, M, E, and A, and close the other valves. The backwash water pump pumps water from the clean water tank to the transparent filter column for water backwashing. The wastewater after backwashing flows to the raw water tank through the pipes where valves E and A are located.

[0034] During the downward flow test: open valves B, C, and E, and close the other valves. The water inlet pump (11) pumps water from the raw water tank to the transparent filter column (7). The water flows from top to bottom, passes through the filter material layer, and flows to the clean water tank through the pipe where valve C is located. During water backwashing, open valves K, M, E, and A, and close the other valves. The backwash water pump pumps water from the clean water tank to the transparent filter column for water backwashing. The wastewater after backwashing flows to the raw water tank through the pipes where valves E and A are located.

[0035] Air backwash: Open valve N, close the other valves, and use the backwash air compressor to flush the transparent filter column with air.

[0036] Preferably, the method is also used to measure the permeability coefficient K of the downward and upward flow filter layers, the height difference ΔH on the pressure measuring tube, the distance ΔL between the pressure measuring tube connections, and the limiting filtration rate V max Factors are measured, including:

[0037] Determination process of permeability coefficient of downward flow filter layer:

[0038] Step 1.1: After the test begins, water is pumped into the upper inlet of the transparent filter column using a water pump. The top cover of the transparent filter column is closed, and the bottom outlet valve is opened. Water flows from the top of the filter layer to the bottom. The constant flow rate of the inlet water is adjusted in steps to keep the pressure drop ΔH at the filter layer height stable for a period of time. The bottom outlet water Q during this period is recorded.

[0039] Step 1.2: When the height difference ΔH on the graduated glass tubes is equal to the distance ΔL between the tubes, the permeability coefficient is calculated based on Darcy's law.

[0040] Step 1.3: If the height difference ΔH on the graduated glass tubes is smaller than the distance ΔL between the tubes, it indicates that the particle size is large and the filtration rate is too high. The height difference on at least two graduated glass tubes can be used to fit the instantaneous filtration rate curve and analyze the permeability coefficient.

[0041] Steps for determining the permeability coefficient of the upward flow filter layer:

[0042] Step 2.1: After the test begins, use the water pump to drive water into the water inlet at the lower end of the transparent filter column. Open the overflow port on the top cover of the transparent filter column, and the water flows from the bottom of the filter layer to the top. Adjust the constant flow rate of the inlet water in steps to keep the pressure drop ΔH at the height of the filter layer stable for a period of time. Record the top water outlet Q during this period.

[0043] Step 2.2: When the height difference ΔH on the graduated glass tubes is equal to the distance ΔL between the tubes, the permeability coefficient is calculated based on Darcy's law.

[0044] Step 2.3: If the height difference ΔH on the graduated glass tube set is smaller than the distance ΔL between the glass graduated tube sets, it indicates that the particle size is large and the filtration rate is too high. The height difference on at least two graduated glass tube sets can be used to fit the instantaneous filtration rate curve and then analyze the permeability coefficient.

[0045] Step 2.4: The filtration rate when the filter material with the smallest particle size on the surface of the filter material begins to fluidize is the limiting filtration rate V max .

[0046] Preferably, the method is also used to determine the constant filtration rate V of the downward and upward flow filter layer filtration performance factor. h , operation time T, filtration end head loss H t , inlet turbidity C0, outlet turbidity C e , limit head loss H lim , limit turbidity C lim And the total thickness of the filter layer L factor is measured;

[0047] The steps for determining the filtration performance factor of the downward and upward flow filter layers include: setting a constant filtration rate V for the influent of the deviceh and the inlet turbidity C0. After the system has been running for a certain time T, the head loss H at the end of filtration is measured. t and effluent turbidity C e , determine the limit head loss H lim , limit turbidity C lim , based on the relevant index evaluation system, the factors are analyzed to make a comprehensive evaluation of the filtration performance.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] The present invention has a wide range of filter media particle sizes for permeability coefficient testing. The conventional water tank constant water pressure head, when affected by factors such as excessive filter media particle size and lower water outlet diameter, results in too low a filtration rate, resulting in ΔH < ΔL, an insignificant change in ΔH, and a large error in permeability coefficient measurement. The present invention uses an adjustable water pump to inlet water, capable of step-by-step adjustment of the constant inlet flow rate. For filter media of different particle sizes, the instantaneous filtration rate V can be fitted by two or more ΔHs. x The changing curve of the filter layer thickness is used to obtain the fitting filtration rate V under the current filter layer thickness. n , that is, the permeability coefficient K n ;

[0050] During the upward flow test of the filter, the limiting filtration velocity V in the boundary area between laminar flow and turbulent flow can be determined. max .

[0051] The present invention can conveniently switch between the permeability coefficient and filtration performance measurement modes of upward flow and downward flow in the filter layer, standardize the sizes of the inlet and outlet joints, and the test device components have strong versatility.

[0052] The present invention can perform stratified and combined measurements on filter media. The water inlet and outlet systems, the calibration system, and the filter column connection points are designed with spacings of 5cm, 10cm, 15cm, 20cm, 25cm, and 30cm, meeting the requirements for stratified and combined analysis of filter media at different spacing heights.

[0053] The present invention is provided with an air-water backwashing system. In tests of filter layers with different thicknesses, the cycle of replacing filter materials can be selected to maintain the continuity of the test.

[0054] The present invention has the ability to collect flow rate and turbidity (solid suspended matter concentration) online.

[0055] The present invention carries out miniaturized integrated design for dispersed components, which is convenient for storage, transportation and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The accompanying drawings are intended to illustrate the details and structures of the present invention in more depth to facilitate understanding, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention, but do not constitute a limitation of the present invention.

[0057] In the attached figure:

[0058] Figure 1 It is a schematic diagram of the external structure of the present invention.

[0059] Figure 2 for Figure 1 Schematic diagram of the left view structure.

[0060] Figure 3 It is a schematic diagram of the internal structure of the present invention.

[0061] Figure 4 for Figure 3 A partial enlarged view of .

[0062] Figure 5 It is a structural schematic diagram of the drawer-type water tank in the present invention.

[0063] Figure 6 This is the schematic diagram of the downward flow test.

[0064] Figure 7 This is the schematic diagram of the upward flow test.

[0065] Figure 8 Schematic diagram of quartz sand head loss at different filter layer heights.

[0066] Figure 9 Schematic diagram of SS outlet from quartz sand with different filter layer heights.

[0067] Figure 10 Schematic diagram of head loss in 90cm filter layer filtration of pyrite with different particle sizes.

[0068] Figure 11 Schematic diagram of SS effluent from the 90 cm filter layer of pyrite with different particle sizes.

[0069] In the figure: 1- movable buckle, 2- sealing rubber sleeve, 3- glass scale tube A, 4- first valve assembly, 5- door panel, 6- metal hose, 7- transparent filter column, 8- recoil air compressor, 9- valve M, 10- recoil water pump, 11- water inlet pump, 12- valve K, 13- valve A, 14- turbidity monitor A, 15- flow meter A, 16- valve C, 17- drawer type water tank, 18- valve L, 19- valve B, 20-handle, 21-valve N, 22-glass graduated tube B, 23-sealing cover, 24-valve F, 25-flow meter B, 26-turbidity monitor B, 27-valve E, 28-valve D, 29-hose, 30-main frame structure, 31-PLD control cabinet, 32-box door, 33-tool cabinet, 34-filter cap, 35-slide rail, 36-roller, 37-pyrite particles, 38-support layer. DETAILED DESCRIPTION

[0070] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0071] See also Figure 1-Figure 7 The integrated device for comprehensive evaluation and determination of filtration performance of filter media in a filter pool provided by an embodiment of the present invention includes a box structure, which includes a main frame structure 30, a box door 32, a slide rail 35, and a tool cabinet 33. The box structure is also provided with a water inlet and outlet system, a filtration system, a backwash system, a pressure differential measuring pipe system, and a PLC control system;

[0072] The water inlet and outlet system includes a water inlet pump 11, a hose and a drawer-type water tank 17. The drawer-type water tank 17 is provided with two groups in the main frame structure 30. The filtration system includes a transparent filter column 7 and pyrite particles 37, a supporting layer 38 and a filter cap 34 sequentially arranged in the transparent filter column 7. A sealing cover plate 23 is also provided on the top of the transparent filter column 7. The differential pressure measuring tube system includes a glass scale tube group, which is arranged on the door panel 5 of the box door 32. There are multiple groups of glass scale tube groups, and the multiple groups of glass scale tube groups are respectively connected to the transparent filter column 7 through metal hoses 6. The water inlet pump 11 and the transparent filter column 7 and the water inlet pump 11 and the drawer-type water tank 17 are all connected through pipes. A hose 29 is also provided between one group of pipes and the upper drawer-type water tank 17.

[0073] A second valve assembly is also provided on the pipeline where the water inlet pump 11 is located. The second valve assembly includes valve A13, valve B19, valve C16, valve D28, valve E27 and valve F24;

[0074] The pipeline where the water inlet pump 11 is located is also equipped with a turbidity monitor A14, a flow meter A15, a flow meter B25 and a turbidity monitor B26; the electronic flow meter (flow meter A15, flow meter B25) on the water inlet pipeline accurately measures the instantaneous flow rate Q of the inlet water. If the inner diameter cross-sectional area A of the filter column is known, the instantaneous filtration rate V can be calculated. x ; Installing an online turbidity meter (turbidity monitor A14, turbidity monitor B26) or online suspended solids concentration meter on the water inlet pipe can accurately measure the C0 value (or SSO value); installing an online turbidity meter (or online suspended solids concentration meter) on the water outlet pipe can accurately measure the C e Value (or SS e value);

[0075] The metal hose 6 is further provided with a first valve assembly 4, which includes a valve G, a valve H, a valve I, and a valve J, and the valves G, H, I, and J are respectively provided on the metal hose 6; wherein the multiple groups of metal hoses 6 are arranged at equal intervals, so that the connection points of the water inlet and outlet systems, the pressure difference measuring tube system, and the transparent filter column are designed with intervals of 5 cm, 10 cm, 15 cm, 20 cm, 25 cm, and 30 cm, so as to meet the layered and combined analysis of filter materials with different spacing heights, and the sizes of the inlet and outlet joints are standardized and unified, the test device components are highly versatile, and the permeability coefficient and filtration performance measurement mode of the upward flow and downward flow of the filter layer can be conveniently switched;

[0076] The door panel 5 is also equipped with a movable buckle 1 for fixing the glass scale tube set. The glass scale tube set includes a glass scale tube A3 and a glass scale tube B22. The glass scale tube A3 and the glass scale tube B22 are spliced together by a sealing rubber sleeve 2 to increase the measuring range. The glass scale tube B22 can be fixed to the other door panel 5 by the movable buckle 1 for storage.

[0077] The drawer-type water tank 17 is further provided with a handle 20 , and the bottom of the drawer-type water tank 17 is provided with a roller 36 for use with a slide rail 35 ;

[0078] The backwash system includes a backwash air compressor 8 and a backwash water pump, and the backwash air compressor 8 and the backwash water pump are connected to the transparent filter column and the drawer-type water tank 17 through pipes;

[0079] The pipeline where the backwash air compressor 8 and the backwash water pump are located is further provided with a valve K12, a valve L18, a valve M9 and a valve N21.

[0080] The PLC control system includes a PLD control cabinet 31 and cables, wherein the PLD control cabinet 31 is located above the tool cabinet 33. The setting of the tool cabinet 33 can improve the storage capacity of the device, and the setting of the PLD control cabinet 31 can facilitate the control of components in the device.

[0081] In an embodiment of the present invention, during the upward flow test, the upper drawer-type water tank 17 is a clean water tank, and the lower drawer-type water tank 17 is a raw water tank; during the downward flow test, the upper drawer-type water tank 17 is a raw water tank, and the lower drawer-type water tank 17 is a clean water tank; the dispersed components are miniaturized and integrated for easy storage, transportation and use; an air-water backwash system is provided, and when testing filter layers of different thicknesses, there is no need to frequently replace the filter material; the device covers a wide range of filter material particle size measurements, and the filter tank downward flow and upward flow measurement modes can be easily switched, the filter layer (pyrite particles 37) can be layered and a large number of layers can be selected, the test equipment components are universal and highly integrated, with a backwash function and an automatic online monitoring function for parameters.

[0082] See also Figure 1-Figure 7 The embodiment of the present invention provides a method for comprehensively evaluating and measuring the filtration performance of filter media in a filter pool, using the above-mentioned integrated device for comprehensively evaluating and measuring the filtration performance of filter media in a filter pool. The method comprises the following steps:

[0083] During the upward flow test: open valves A13, D28, and F24, and close the remaining valves. The inlet pump 11 pumps water from the raw water tank (the lower drawer-type water tank 17) to the transparent filter column 7. The water flows from bottom to top, passes through the filter material layer (pyrite particles 37), and then flows through the pipe where valve F24 is located to the clean water tank (the upper drawer-type water tank 17). During water backwashing, open valves L18, M9, E27, and A13, and close the remaining valves. The backwash pump 10 pumps water from the clean water tank (the upper drawer-type water tank 17) to the transparent filter column 7 for water backwashing. The wastewater after backwashing flows through the pipes where valves E27 and A13 are located to the raw water tank (the lower drawer-type water tank 17).

[0084] During the downward flow test: open valves B19, C16, and E27, and close the remaining valves. The water inlet pump 11 causes gravity flow from the raw water tank (the upper drawer-type water tank 17) to the transparent filter column 7. Water flows from top to bottom, passes through the filter layer, and then flows through the pipe where valve C16 is located to the clean water tank (the lower drawer-type water tank 17). During water backwashing, open valves K12, M9, E27, and A13, and close the remaining valves. The backwash pump 10 pumps water from the clean water tank (the lower drawer-type water tank 17) to the transparent filter column 7 for water backwashing. The wastewater after backwashing flows through the pipes where valves E27 and A13 are located to the raw water tank (the upper drawer-type water tank 17).

[0085] Air backwashing: open valve N21, close other valves, and use the backwash air compressor 8 to flush the transparent filter column 7 with air;

[0086] The method is also used to determine the permeability coefficient K of the downward and upward flow filter layers, the height difference ΔH on the pressure measuring tube, the distance ΔL between the pressure measuring tube connections, and the limiting filtration rate V. max Factors are measured, including:

[0087] Determination process of permeability coefficient of downward flow filter layer:

[0088] Step 1.1: After the test begins, water is introduced into the upper water inlet of the transparent filter column 7 using the water inlet pump 11. The top cover of the transparent filter column 7 is closed, and the bottom water outlet valve is opened. Water flows from the top of the filter layer to the bottom. The constant flow rate of the inlet water is adjusted in steps to keep the pressure drop (i.e., the height difference on the pressure measuring tube) ΔH at the filter layer height stable for a period of time. The bottom water outlet Q during this period is recorded.

[0089] Step 1.2: When the height difference ΔH on the graduated glass tubes is equal to the distance ΔL between the tubes, the permeability coefficient is calculated based on Darcy's law.

[0090] Step 1.3: If the height difference ΔH on the graduated glass tubes is smaller than the distance ΔL between the tubes, it indicates that the particle size is large and the filtration rate is too high. The height difference on at least two graduated glass tubes can be used to fit the instantaneous filtration rate curve and analyze the permeability coefficient.

[0091] Steps for determining the permeability coefficient of the upward flow filter layer:

[0092] Step 2.1: After the test begins, water is introduced into the water inlet at the lower end of the transparent filter column 7 using the water inlet pump 11. The water flows from the overflow port on the top cover of the transparent filter column 7 upward from the bottom of the filter layer to the top. The constant flow rate of the inlet water is adjusted in steps to keep the pressure drop (i.e., the height difference on the pressure measuring tube) ΔH at the filter layer height stable for a period of time. The top water outlet Q during this period is recorded.

[0093] Step 2.2: When the height difference ΔH on the graduated glass tubes is equal to the distance ΔL between the tubes, the permeability coefficient is calculated based on Darcy's law.

[0094] Step 2.3: If the height difference ΔH on the graduated glass tube set is smaller than the distance ΔL between the glass graduated tube sets, it indicates that the particle size is large and the filtration rate is too high. The height difference on at least two graduated glass tube sets can be used to fit the instantaneous filtration rate curve and then analyze the permeability coefficient.

[0095] Step 2.4: The filtration rate when the filter material with the smallest particle size on the surface of the filter material begins to fluidize is the limiting filtration rate V max ;

[0096] The adjustable water inlet pump 11 is used to inlet water, which can adjust the constant flow rate of the inlet water in steps. For filter materials with different particle sizes, the instantaneous filtration rate V can be fitted by two or more ΔH. x The changing curve of the filter layer thickness is used to obtain the fitting filtration rate V under the current filter layer thickness. n , that is, the permeability coefficient K n ;

[0097] In the upward flow state, when the expansion rate e = 0, the filtration rate is at the limit stage where nonlinear turbulence is about to occur, so it is also called the limit filtration rate;

[0098] The method is also used to measure the filtration performance factor of the downward and upward flow filter layers at a constant filtration rate V h , operation time T, filtration end head loss H t , inlet turbidity C0 (or suspended solids concentration SS0), outlet turbidity C e (or suspended solids concentration SSe ), limit head loss H lim , limit turbidity C lim (or limiting suspended solids concentration SS lim ) and the total thickness of the filter layer L factor for determination;

[0099] The steps for determining the filtration performance factor of the downward and upward flow filter layers include: setting a constant filtration rate V for the influent of the device h And the inlet turbidity C0 (or suspended solids concentration SS0), when the system runs for a certain time T, the final filtration head loss H is measured t and effluent turbidity C e (or suspended solids concentration SS e ), determine the limit head loss H lim , limit turbidity C lim (or limiting suspended solids concentration SS lim ), and analyze the factors according to the relevant index evaluation system to make a comprehensive evaluation of the filtration performance.

[0100] Application Case 1: Determination of Upflow Permeability Coefficient of Quartz Sand Filter Media

[0101] This application simulates an upward flow drinking water filter. The test drinking water turbidity is 1NTU. The quartz sand filter media particle size is 1.7-3.3mm. The test filter layer thickness ΔL is 30cm, 60cm, and 90cm. During the test, a certain filter layer thickness is selected, the water inlet pump is turned on to adjust the flow rate, and the pressure drop at two different filter layer heights (i.e., the height difference on the pressure measuring tube) is read. The balance is maintained for about 60 seconds, as shown in Table 1. The relevant data is recorded and a curve is fitted based on the data. The pressure drop at the filter layer height is the same as the filter media height. The corresponding filtration rate at this time is the permeability coefficient of this filter layer thickness in the current state. During the upward flow test of the filter, when the filter media with the smallest particle size on the surface of the filter media begins to fluidize, the limiting filtration rate V at the boundary between laminar flow and turbulent flow is max .

[0102] Table 1 Upward flow permeability coefficient of quartz sand filter media

[0103]

[0104] Application Case 2: Determination and Comprehensive Evaluation of Upflow Filtration Factor of Quartz Sand Filter Media

[0105] This application simulates an upward flow sewage biological filter, using quartz sand filter media with a particle size of 1.7-3.3 mm, filter layer thickness ΔL of 30 cm, 60 cm, and 90 cm, raw water SS0 = 20 mg / L, and a constant filtration rate V h =5m / h, Figure 8 、 Figure 9The head loss H of quartz sand with particle size of 1.7-3.3mm in 30cm, 60cm and 90cm filter layers is respectively t and inlet and outlet water SS0, SS e Table 2 shows the filtration performance factor measurement results and comprehensive evaluation after the system has been running for 30 hours.

[0106] Table 2 Determination and comprehensive evaluation of upward filtration performance factors of quartz sand filter media

[0107]

[0108] Application Case 3: Determination of Downward Permeability Coefficient of Pyrite Granular Filter Media

[0109] This application simulates a downward flow biofilter, SS0 = 20 mg / L, the pyrite granular filter material used has a particle size of 2.0-3.0 mm, and the test filter layer thickness ΔL is 30 cm, 60 cm, and 90 cm. During the test, a certain filter layer thickness is selected, the water inlet pump is started, and the flow rate is increased to a preset specific value. The pressure drop at the filter layer height (i.e., the height difference on the pressure measuring tube) ΔH = ΔL is maintained in equilibrium for about 60 seconds, as shown in Table 3. There is no need to use a fitting curve to calculate, and the relevant data is recorded. The corresponding filtration rate at this time is the permeability coefficient of this filter layer thickness in the current state. The downward flow is affected by the density of the particles' own weight, and the changes in the interface between laminar flow and turbulent flow are very subtle and difficult to identify, so it is difficult to determine the limiting filtration rate V max .

[0110] Table 3 Determination of downward flow permeability coefficient of pyrite granular filter material

[0111]

[0112] Application Case 4: Determination and Comprehensive Evaluation of Upflow Filtration Performance Factors of Pyrite Granular Filter Media

[0113] This application simulates an upflow biofilter with pyrite granular filter media of 0.6-1.0mm, 1.0-2.0mm, 2.0-3.0mm, 3.0-5.0mm and 5.0-8.0mm, and a filter layer thickness ΔL of 60cm. For reference tests, a filter layer thickness of 90cm was added to the filter media of 2.0-3.0mm and 3.0-5.0mm, with influent SS0=60 and a constant filtration rate V h =5m / h, Figure 10 、 Figure 11 The head loss H of ferrous sulfide granular filter media with particle sizes of 0.6-1.0mm, 1.0-2.0mm, 2.0-3.0mm, 3.0-5.0mm and 5.0-8.0mm in the 60cm and 90cm filter layers respectively t and inlet and outlet water SS0, SS eTable 4 shows the filtration performance factor measurement results and comprehensive evaluation after the system has been running for 30 hours.

[0114] Table 4 Determination and evaluation of upward flow filtration performance factors of pyrite granular filter media

[0115] Particle size ΔH <![CDATA[V h ]]> <![CDATA[H t ]]> T <![CDATA[SS0]]> <![CDATA[SS e ]]> FPI F SC JP (mm) cm m / h cm h mg / L mg / L <![CDATA[(×10 -2 )]]> <![CDATA[(×10 -4 )]]> <![CDATA[(×10 -3 )]]> <![CDATA[(×10 -8 )]]> 0.5-1.0 90 5 10 30 20 3 15 0.89 26 6.154 1.0-2.0 90 5 2.6 30 20 8 58 0.66 71 6.465 2.0-3.0 90 5 1.5 30 20 9 100 0.45 110 4.909 3.0-5.0 90 5 0.8 30 20 13 188 0.36 125 6.400 5.0-8.0 90 5 0.3 30 20 16 500 0.16 195 4.954 2.0-3.0 60 5 1.1 30 20 11 136 0.40 123 3.585 2.0-3.0 30 5 0.9 30 20 12 167 0.37 128 1.930

[0116] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An integrated device for comprehensive evaluation and determination of filtration performance of filter media in a filter tank, comprising a box structure, wherein the box structure comprises a main frame structure (30), a box door (32), a slide rail (35) and a tool cabinet (33), and the box structure is further provided with a water inlet and outlet system, a filtration system, a backwash system, a pressure difference measuring pipe system and a PLC control system, characterized in that: The water inlet and outlet system includes a water inlet pump (11), a hose and a drawer-type water tank (17). The drawer-type water tank (17) is provided with two upper and lower parts in the main frame structure (30), including an upper drawer-type water tank (17) and a lower drawer-type water tank (17); a handle (20) is provided on the drawer-type water tank (17), and a roller (36) for use with a slide rail (35) is provided at the bottom of the drawer-type water tank (17); the filtration system includes a transparent filter column (7) and sulfide iron arranged in sequence in the transparent filter column (7). The filter cartridge (34) is provided with a mineral particle (37), a supporting layer (38) and a filter cap (34), and a sealing cover plate (23) is further provided on the top of the transparent filter column (7). The differential pressure measuring tube system comprises a glass scale tube group, which is provided on the door panel (5) of the box door (32). There are multiple glass scale tube groups, and the multiple glass scale tube groups are connected to the transparent filter column (7) through metal hoses (6). The water inlet pump (11) and the transparent filter column (7) and the water inlet pump (11) and the drawer-type water tank (17) are all connected through pipelines. The door panel (5) is also equipped with a movable buckle (1) for fixing a glass scale tube group, each group of glass scale tubes includes a glass scale tube A (3) and a glass scale tube B (22), and the glass scale tube A (3) and the glass scale tube B (22) are spliced together by a sealing rubber sleeve (2); The backwash system comprises a backwash air compressor (8) and a backwash water pump (10), wherein the backwash air compressor (8) is connected to the transparent filter column via a pipeline, and the backwash water pump (10) is connected to the transparent filter column and the drawer-type water tank (17) via a pipeline; The pipeline where the backwash air compressor (8) and the backwash water pump (10) are located is also provided with a valve K (12), a valve L (18), a valve M (9) and a valve N (21); A second valve assembly is also provided on the pipeline where the water inlet pump (11) is located, and the second valve assembly includes valve A (13), valve B (19), valve C (16), valve D (28), valve E (27) and valve F (24); The specific settings for pipes and valves are: One end of the water inlet pump (11) is provided with a pipe 1 connected to the lower drawer-type water tank (17), and the other end of the water inlet pump (11) is provided with a pipe 2 for connecting to one side of the lower end of the transparent filter column (7); a pipe 3 for connecting to the upper drawer-type water tank (17) is provided on the pipe 1, a valve B (19) is provided on the pipe 3, and a valve A (13) is provided on the pipe 1 between the pipe 3 and the lower drawer-type water tank (17); a valve B (19) is provided on the pipe 2 for connecting to the lower drawer-type water tank (17). A pipe 4 is connected to the water inlet pump (11), and a valve C (16) is provided on the pipe 4. A pipe 5 connected to one side of the upper end of the transparent filter column (7) is provided on the pipe 2 between the pipe 4 and the water inlet pump (11). A hose (29) connected to the upper drawer-type water tank (17) is provided on the pipe 5, and a valve F (24) is provided on the hose (29); a valve D (28) is provided on the pipe 2 between the pipe 4 and the pipe 5; and a valve E (27) is provided on the pipe 5 between the hose (29) and the pipe 2. One end of the backwash water pump (10) is provided with a pipe 6 connected to the lower drawer-type water tank (17); the other end of the backwash water pump (10) is provided with a pipe 7 connected to the transparent filter column (7), and a valve M (9) is provided on the pipe 7; a pipe 8 connected to the upper drawer-type water tank (17) is provided on the pipe 6, and a valve L (18) is provided on the pipe 8; a valve K (12) is provided on the pipe 6 between the pipe 8 and the lower drawer-type water tank (17); The valve N (21) is located on the pipeline between the recoil air compressor (8) and the transparent filter column (7); The pipeline four is also provided with a turbidity monitor A (14), a flow meter A (15); the hose (29) is provided with a flow meter B (25) and a turbidity monitor B (26); During the upward flow test: the upper drawer-type water tank is the clean water tank, and the lower drawer-type water tank is the raw water tank; valve A (13), valve D (28), and valve F (24) are opened, and the other valves are closed. The water inlet pump (11) pumps water from the raw water tank to the transparent filter column (7), and the water flows from bottom to top, passes through the filter material layer, and flows to the clean water tank through the hose (29) where valve F (24) is located; during water backwashing, valve L (18), valve M (9), valve E (27), and valve A (13) are opened, and the other valves are closed. The backwashing water pump (10) pumps water from the clean water tank to the transparent filter column (7), and performs the water backwashing operation. The wastewater after backwashing flows to the raw water tank through the pipes where valves E (27) and valve A (13) are located; During the downward flow test: the upper drawer-type water tank (17) is the raw water tank, and the lower drawer-type water tank (17) is the clean water tank; valve B (19), valve C (16), and valve E (27) are opened, and the other valves are closed. The water inlet pump (11) pumps water from the raw water tank to the transparent filter column (7). When the water flows from top to bottom, it passes through the filter material layer and flows to the clean water tank through the pipe where valve C (16) is located; during water backwashing, valve K (12), valve M (9), valve E (27), and valve A (13) are opened, and the other valves are closed. The backwash water pump (10) pumps water from the clean water tank to the transparent filter column (7) for water backwashing. The wastewater after backwashing flows to the raw water tank through the pipe where valve E (27) and valve A (13) are located. Air backwashing: Open valve N (21), close other valves, and use the backwash air compressor (8) to flush the transparent filter column (7) with air.

2. The integrated device for comprehensive evaluation and determination of filtration performance of filter media according to claim 1, characterized in that: The metal hose (6) is also provided with a first valve assembly (4), the first valve assembly (4) comprising a valve G, a valve H, a valve I and a valve J, and the valves G, H, I and J are respectively provided on the metal hose (6) connected to each set of glass graduated tubes.

3. A method for comprehensively evaluating and measuring the filtration performance of filter media in a filter pool, using the integrated device for comprehensively evaluating and measuring the filtration performance of filter media in a filter pool as claimed in claim 1, characterized in that: The method comprises the following steps: During the upward flow test: open valve A (13), valve D (28), and valve F (24), and close the other valves. The water inlet pump (11) pumps water from the raw water tank to the transparent filter column (7). The water flows from bottom to top, passes through the filter material layer, and flows to the clean water tank through the hose (29) where valve F (24) is located. During water backwashing, open valve L (18), valve M (9), valve E (27), and valve A (13), and close the other valves. The backwashing water pump (10) pumps water from the clean water tank to the transparent filter column (7), and performs the water backwashing operation. The wastewater after backwashing flows to the raw water tank through the pipes where valves E (27) and valve A (13) are located. During the downward flow test: open valve B (19), valve C (16), and valve E (27), and close the other valves. The water inlet pump (11) pumps water from the raw water tank to the transparent filter column (7). When the water flows from top to bottom, it passes through the filter material layer and flows to the clean water tank through the pipe where valve C (16) is located. During water backwashing, open valve K (12), valve M (9), valve E (27), and valve A (13), and close the other valves. The backwash water pump (10) pumps water from the clean water tank to the transparent filter column (7) for water backwashing. The waste water after backwashing flows to the raw water tank through the pipe where valve E (27) and valve A (13) are located. Air backwashing: Open valve N (21), close other valves, and use the backwash air compressor (8) to flush the transparent filter column (7) with air.

4. The method for comprehensive evaluation of filtration performance of filter media according to claim 3, characterized in that: The method is also used to measure the permeability coefficients of the downward and upward flow filter layers, the height difference on the piezometric tubes, the spacing between the piezometric tube connections, and the limiting filtration rate factor, specifically including: Determination process of permeability coefficient of downward flow filter layer: Step 1.1: After the test begins, water is introduced into the water inlet at the upper end of the transparent filter column (7) using the water inlet pump (11), the top cover of the transparent filter column (7) is closed, the bottom outlet valve is opened, and water flows from the upper part of the filter layer to the lower part. The constant flow rate of the inlet water is adjusted in steps so that the pressure drop ΔH at the height of the filter layer remains stable for a period of operation, and the bottom outlet water Q during this period is recorded; Step 1.2: When the height difference ΔH on the graduated glass tubes is equal to the distance ΔL between the tubes, the permeability coefficient is calculated based on Darcy's law. Step 1.3: If the height difference ΔH on the graduated glass tubes is smaller than the distance ΔL between the tubes, it indicates that the particle size is large and the filtration rate is too high. The permeability coefficient can be analyzed by fitting the change curve of the pressure drop difference and instantaneous filtration rate twice or more. Steps for determining the permeability coefficient of the upward flow filter layer: Step 2.1: After the test begins, water is introduced into the water inlet at the lower end of the transparent filter column (7) by using the water inlet pump (11), and the overflow port on the top cover of the transparent filter column (7) is opened. Water flows from the bottom of the filter layer to the top, and the constant flow rate of the inlet water is adjusted in steps to keep the pressure drop ΔH at the height of the filter layer stable for a period of operation. The top water outlet Q during this period is recorded; Step 2.2: When the height difference ΔH on the graduated glass tubes is equal to the distance ΔL between the tubes, the permeability coefficient is calculated based on Darcy's law. Step 2.3: If the height difference ΔH on the graduated glass tube set is smaller than the distance ΔL between the joints of the graduated glass tube set, it indicates that the particle size is large and the filtration rate is too high. The permeability coefficient can be analyzed by fitting the change curve of the pressure drop difference and instantaneous filtration rate twice or more. Step 2.4: The filtration rate when the filter media with the smallest particle size on the surface of the filter media begins to fluidize is the limiting filtration rate.

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