Peristaltic pump flow calculation method and experimental verification

Abstract

The invention relates to a peristaltic pump flow calculation method and experimental verification, and belongs to the technical field of fluid conveying equipment.The method comprises the steps that geometric parameters of a peristaltic pump are measured, and the parameters comprise the pump pipe center line elbow diameter, the roller diameter, the pump pipe inner diameter, the pump pipe outer diameter, the roller number, the rotating speed and the like; the method comprises the following steps: firstly, calculating a theoretical liquid discharge volume when roller extrusion is not considered, then accurately calculating a pump pipe volume occupied when a single roller extrudes a pump pipe, calculating an occupied area through a geometric model and introducing a correction coefficient pi / 4, and finally obtaining an actual output flow; according to experimental verification, under the conditions of different types of peristaltic pumps including U-shaped and linear pump pipes, different rotating speeds and different pump pipe specifications, the calculation error is controlled within 10%, the problems of high calculation complexity and poor universality in the prior art are solved, and the method has the advantages of being high in precision, wide in applicability and easy and convenient to operate.

Description

Technical Field

[0001] This invention relates to a method for calculating the flow rate of a peristaltic pump and its experimental verification, belonging to the field of fluid transport equipment technology, and is applicable to industries that require precise liquid measurement, such as medicine, agriculture, microfluidics, and food packaging. Background Technology

[0002] Peristaltic pumps deliver liquids by alternating squeezing and releasing the pump tube, offering advantages such as good sealing, fluid contamination prevention, and ease of maintenance. Flow rate is a key performance indicator for peristaltic pumps, but theoretical calculations differ from experimental values. Existing flow rate calculation methods mainly include theoretical calculations and 3D modeling: Patent CN111209688A uses 3D software modeling to calculate the roller squeezing volume with an accuracy close to 80%, but it is complex and has low universality; Patent CN119475620A uses SOLIDWORKS drawing to calculate the volume with an accuracy close to 90%, but the process is complex; Patent CN120144909A uses a straight line to approximate the pump tube arc length with an accuracy of approximately 90%, but it is only applicable to U-shaped pump tubes.

[0003] These methods all suffer from computational complexity and limited applicability. Therefore, a computational method with high accuracy and broad applicability is needed. Summary of the Invention

[0004] This invention overcomes the shortcomings of existing technologies and provides a method for calculating the flow rate of a peristaltic pump and experimental verification. It accurately calculates the pump pipe volume occupied by roller extrusion through a geometric model and introduces a correction coefficient to improve the calculation accuracy and universality.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for calculating the flow rate of a peristaltic pump, comprising the following steps: Step 1: Measure the geometric parameters of the peristaltic pump, including the diameter of the pump tube centerline bend Dc, the roller diameter Dr, the pump tube inner diameter d, the pump tube outer diameter D, the number of rollers N, and the pump head speed n; Step 2: Calculate the volume V of liquid discharged in one rotation of the roller, without considering the volume occupied by the roller extruding the pump pipe;

[0006] Step 3: Calculate the pump tube volume ΔV occupied by a single roller when it extrudes the pump tube; First, calculate the geometric parameters:

[0007] Calculate the areas of sector AOB and triangle AOB:

[0008] Calculate the pump tube area occupied by the roller extrusion:

[0009] To calculate the volume occupied by a single roller extrusion, a correction factor of π / 4 is introduced:

[0010] Step 4: Calculate the actual output liquid volume V0 of the peristaltic pump after one revolution;

[0011] Step 5: Measure the peristaltic pump speed n; Step 6: Calculate the peristaltic pump flow rate Q;

[0012] Furthermore, the pump tube includes a U-shaped pump tube and a straight pump tube, and the method is applicable to various pump tube structures.

[0013] Furthermore, the correction factor π / 4 is determined by the ratio of the area of ​​the circle to the area of ​​the square surrounding the circle, and is used to approximate the volume loss of the pump pipe.

[0014] The present invention provides an experimental verification method for calculating the flow rate of a peristaltic pump, comprising the following steps: a. Select multiple peristaltic pumps of different models, measure their actual flow rates, and calculate the theoretical flow rates and errors; b. Measure the actual flow rate at different speeds using the same peristaltic pump, and calculate the theoretical flow rate and error; c. When using the same peristaltic pump with different specifications of pump tubing, measure the actual flow rate and calculate the theoretical flow rate and error; d. Verify the accuracy of the method described in claim 1 through error analysis, wherein the error calculation formula is: Error = (Theoretical flow rate - Experimental flow rate) / Theoretical flow rate × 100%; e. When the error is controlled within 10%, the method is considered effective.

[0015] Furthermore, the peristaltic pump models include, but are not limited to, KPMP, KPP, KFS, KCS, EPST300, and KHL2000, and the pump tube material is BPT.

[0016] Compared with the prior art, the advantages of this invention are: the invention accurately calculates the occupied area through a geometric model with an error controlled within 10%, achieving high precision; it is applicable to U-shaped and straight pump pipes; it does not require complex three-dimensional modeling, but can be directly calculated through formulas, making it easy to operate; and through multiple sets of experiments, the error is stable and the reliability is high. Attached Figure Description

[0017] The present invention will now be further described with reference to the accompanying drawings.

[0018] Figure 1 This is a three-dimensional schematic diagram of a single roller extrusion pump tube according to the present invention.

[0019] Figure 2 for Figure 1 A schematic diagram of the volume lost due to compression on a single roller.

[0020] Figure 3 This is a two-dimensional plan view of a single roller extrusion pump tube in this invention (green shading indicates the occupied portion).

[0021] Figure 4 The geometric model for calculating the area occupied by this invention (marked with points A, B, C, O, etc.).

[0022] Figure 5 This is a schematic diagram of the correction factor π / 4 of the present invention (ratio of the area of ​​the circle to the area of ​​the square). Detailed Implementation

[0023] The present invention will be further described below with reference to specific embodiments.

[0024] like Figures 1-5 As shown, this invention includes theoretical calculations and experimental verification.

[0025] I. Theoretical Calculations.

[0026] The core of the theoretical calculation in this invention lies in calculating the volume occupied by a single roller when extruding the pump tube. The specific steps are as follows: 1. Measure geometric parameters: Dc, Dr, d, D, N, n.

[0027] 2. Calculate the theoretical discharge volume V:

[0028] 3. Calculate the volume ΔV occupied by a single roller extrusion: Step 1: Assuming the pump tube is squeezed to a remaining thickness of 2 times the wall thickness, draw a circle with the roller axis as the center, intersecting the inner wall of the pump tube at points A and B, and tangent to the inner wall of the pump tube away from the roller at point C; Step 2: Calculate the area of ​​sector AOB and the area of ​​triangle AOB; the difference is the occupied area. ; The third step is to introduce a correction factor of π / 4 and calculate ΔV:

[0029]

[0030] Step 4: Calculate the actual discharge volume V0:

[0031] Step 5: Calculate the flow rate Q:

[0032] Taking the Kamoer KPMP pump as an example (parameters: N=4, Dc=20.4mm, Dr=5.1mm, d=1.3mm, D=3mm, n=300rpm): 1. Calculate V = π² × (1.3)² × 20.4 / 4 ≈ 85 ml; 2. Calculate ΔV: a = (5.1 + 3 - 3 × 1.3) / 2 = 2.1 mm r = (5.1 + 3 - 1.3) / 2 = 3.4 mm β=2×arccos (2.1 / 3.4)≈1.81rad; S circularAOB =(3.4)²×1.81 / 2≈10.46mm²,

[0033] S ABC =10.46-5.62=4.84mm²; ΔV=π / 4×1.3×4.85≈4.94mm³; 3. V0=85-4×4.95≈65.24mm³; 4. Q = 300 × 65.2 / 1000 ≈ 19.6 ml / min (experimental value 17.8 ml / min, error 9%).

[0034] Other embodiments are detailed in the table data. The method of the present invention exhibits high precision and stability under different working conditions.

[0035] II. Experimental verification.

[0036] The accuracy of the method was verified through multiple sets of experiments.

[0037] Table 1: The error of the 6 Kamoer peristaltic pumps under different parameters is ≤10%; Table 2: The error of the same pump is stable (8%~10%) at different speeds. Table 3: The error is stable (5% to 6%) when using different pump tubes for the same pump.

[0038] The following is a specific experimental verification: 1) Six peristaltic pumps from Kamoer were selected, and the pump tubing was made of BPT material. The actual flow rate of each pump was measured, and the theoretical flow rate and error of each pump under the corresponding operating conditions were calculated. See Table 1 for specific data.

[0039] As shown in Table 1, for various types of peristaltic pumps with different numbers of rollers, different pump pipe outlet types, and different rotation speeds, the calculation error between the theoretical flow rate calculated by the formula proposed in this application and the actual flow rate can be controlled within 10%.

[0040] 2) Two peristaltic pumps, Kamoer EPST300 and KHL2000, were selected. The pump tube specifications were Φ4×7.2mm and Φ6.4×11.4mm, respectively. Both pump tubes were made of BPT material. The experimental flow rate of these two pumps at different speeds was measured, and the theoretical flow rate and error under the corresponding operating conditions were calculated. The specific data are shown in Table 2.

[0041]

[0042] As shown in Table 2, for the EPST300 and KHL2000 peristaltic pumps, when different speeds are set, the calculation error of the theoretical flow rate calculated by the formula proposed in this application is relatively stable compared with the experimental flow rate. The calculation error of EPST300 is controlled within 8% to 9%, and the calculation error of KHL2000 is controlled within 9% to 10%.

[0043] 3) Select a Kamoer KPP peristaltic pump with pump tubing specifications of Φ1×3mm, Φ2×4mm, and Φ3×5mm, and a speed of 240rpm. Measure the actual flow rate of the pump when using different pump tubing, and calculate the theoretical flow rate and error of the pump under the corresponding operating conditions. See Table 3 for specific data.

[0044]

[0045] As shown in Table 3, for the same peristaltic pump, the pump flow rate increases with the increase of the pump tube inner diameter. The theoretical flow rate calculated by the formula proposed in this application also increases with the increase of the pump tube inner diameter. Moreover, the error between the theoretical flow rate and the experimental flow rate is relatively stable, and the calculation error is controlled within 5% to 6%.

[0046] Based on Tables 1-3, this invention can be applied to multiple peristaltic pump products. In the same product, if the pump pipe specifications change, only the corresponding parameters need to be changed during calculation to obtain a high accuracy in theoretical flow calculation and control the calculation error within 10%.

[0047] The meanings of the parameters involved in this invention are shown in Table 4.

[0048]

[0049] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for calculating the flow rate of a peristaltic pump, characterized in that, Includes the following steps: Step 1: Measure the geometric parameters of the peristaltic pump, including the diameter of the pump tube centerline bend Dc, the roller diameter Dr, the pump tube inner diameter d, the pump tube outer diameter D, the number of rollers N, and the pump head speed n; Step 2: Calculate the volume V of liquid discharged in one rotation of the roller, without considering the volume occupied by the roller extruding the pump pipe; Step 3: Calculate the pump tube volume ΔV occupied by a single roller when extruding the pump tube; first calculate the geometric parameters: Calculate the areas of sector AOB and triangle AOB: Calculate the pump tube area occupied by the roller extrusion: To calculate the volume occupied by a single roller extrusion, a correction factor of π / 4 is introduced: Step 4: Calculate the actual output liquid volume V0 of the peristaltic pump after one revolution; Step 5: Measure the peristaltic pump speed n; Step 6: Calculate the peristaltic pump flow rate Q; 2. The method for calculating the flow rate of a peristaltic pump according to claim 1, characterized in that, The pump tube includes U-shaped pump tubes and straight pump tubes, and the method is applicable to various pump tube structures.

3. The method for calculating the flow rate of a peristaltic pump according to claim 1, characterized in that, The correction factor π / 4 is determined by the ratio of the area of ​​the circle to the area of ​​the square surrounding the circle, and is used to approximate the volume loss of the pump pipe.

4. An experimental verification method for calculating the flow rate of a peristaltic pump, characterized in that, Includes the following steps: a. Select multiple peristaltic pumps of different models, measure their actual flow rates, and calculate the theoretical flow rates and errors; b. Measure the actual flow rate at different speeds using the same peristaltic pump, and calculate the theoretical flow rate and error; c. When using the same peristaltic pump with different specifications of pump tubing, measure the actual flow rate and calculate the theoretical flow rate and error; d. Verify the accuracy of the method described in claim 1 through error analysis, wherein the error calculation formula is: Error = (Theoretical flow rate - Experimental flow rate) / Theoretical flow rate × 100%; e. When the error is controlled within 10%, the method is considered effective.

5. The experimental verification method according to claim 4, characterized in that, The peristaltic pump models include, but are not limited to, KPMP, KPP, KFS, KCS, EPST300, and KHL2000, and the pump tubing material is BPT.

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