Method for calculating theoretical flow of peristaltic pump

Abstract

The invention relates to the technical field of peristaltic pump detection, in particular to a theoretical flow calculation method for a peristaltic pump. The method comprises the following steps: step 1, measuring the following parameters of the peristaltic pump: the inner diameter D of a pump shell, the inner diameter d of a hose, the wall thickness delta of the hose, the diameter R of a roller, the radius L of the circumference where the center of the roller is located and the rotating speed n of a motor; 2, the circular section of the hose is equivalent to a rectangle with the same area, the height of the rectangle is d, and the width h is equal to pi d / 4; 3, drawing the theoretical shape of the hose; 4, measuring the area of the internal area of the annular hose in the theoretical shape as an equivalent flow area S; and 5, calculating the theoretical flow of the peristaltic pump: V = n * S * h. The circular section of the hose is equivalent to a rectangle with the same area, so that the calculation precision of theoretical flow can be effectively improved, and the calculation precision is kept at about 90% or more than 90%.

Description

Technical Field

[0001] The present application relates to the technical field of peristaltic pump detection, and in particular to a method for calculating theoretical flow of a peristaltic pump. Background Art

[0002] Common peristaltic pumps, such as the one in the instruction manual Figure 1 As shown, its structure includes a pump housing, a hose, a roller and a motor. The pump housing has a circular cavity inside, and the hose is arranged inside the cavity and is in close contact with the inside of the cavity, so that the hose is arranged in a ring shape as a whole. The roller is arranged inside the cavity and abuts against the hose. There are usually multiple rollers, with three or four being common and dozens of rollers being common. The multiple rollers are all arranged on a rotating bracket, and the rotating bracket rotates under the drive of the motor, thereby driving the roller to revolve. As the rollers continue to rotate and squeeze the hose, the fluid can be pumped.

[0003] Since the fluid is isolated in the hose, it has the advantages of no pollution, high precision and simple maintenance. Among them, since the peristaltic pump has high repeatability and stability accuracy, it is suitable for applications requiring precise measurement, so it is suitable for drug preparation and pharmaceutical production.

[0004] In the production and manufacturing of peristaltic pumps, in order to ensure the accuracy of the peristaltic pump, it is necessary to verify and calculate the theoretical flow rate and actual flow rate of the peristaltic pump to avoid the situation where the theoretical flow rate and the actual flow rate are very different. For the calculation of the theoretical flow rate of the peristaltic pump, the volume of the hose between two adjacent rollers is generally calculated first, and then the output displacement of the peristaltic pump is calculated after one cycle of operation to calculate the theoretical flow rate.

[0005] However, in actual situations, the shape of the hose is irregular when it is bent and squeezed by the rollers, especially in the position where the hose is squeezed, where it is severely deformed, and it is difficult to accurately calculate its volume.

[0006] In current related research, the journal article "Theoretical Calculation and Experimental Verification of Peristaltic Pump Flow" in Chemical Automation and Instrumentation uses the accumulation method to calculate the flow, but ignores the volume occupied by the peristaltic pump roller when squeezing the hose, resulting in a large error; another related patent CN111209688A uses three-dimensional software modeling to obtain the volume occupied by roller extrusion, making the calculation accuracy close to 80%, but this method has a certain complexity and its universality remains to be proven.

[0007] Therefore, when calculating the volume of the pump tube between two adjacent rollers, the above method often ignores the deformation of the hose during peristalsis and the influence of roller squeezing on the flow rate, resulting in a large calculation deviation and low calculation accuracy. Summary of the invention

[0008] The present application provides a method for calculating the theoretical flow rate of a peristaltic pump, comprising the following steps: Step 1: Measure the following parameters of the peristaltic pump: inner diameter D of the pump housing, inner diameter d of the hose, wall thickness δ of the hose, diameter R of the roller, radius L of the circle where the center of the roller is located, and motor speed n; Step 2: Equivalent the circular cross section of the hose to a rectangle with the same area. The height of the rectangle is d, and the width is h = πd / 4; Step 3: Draw the theoretical shape of the hose after being squeezed by the roller using the parameters in step 1. The hose is arranged in a circular ring shape. The outer diameter of the ring hose is equal to the inner diameter D of the pump housing. The roller is arranged on the inner side of the hose. The hose includes an equal diameter portion and a deformation portion. The deformation portion has an arc-shaped depression and fits the surface of the roller. Step 4: In the theoretical shape of the hose, measure the area of ​​the inner region of the annular hose as the equivalent flow area S; Step 5: Calculate the theoretical flow rate of the peristaltic pump: V = n*S*h.

[0009] By adopting the above technical solution, by making the circular cross-section of the hose equivalent to a rectangle with equal area, and by calculating the area of ​​the internal area of ​​the annular hose as the equivalent flow area S, the influence of the hose deformation on the calculation accuracy when calculating the theoretical flow of the peristaltic pump can be effectively reduced, so that the calculation of the theoretical flow has higher accuracy and the calculation accuracy can be maintained at about 90% or above 90%.

[0010] Preferably, the number of rollers is A, then the internal area of ​​the hose between two adjacent rollers S1 = equivalent flow area S / A = internal area of ​​the equal diameter part S2 + internal area of ​​the deformation part S3*2; The internal area S1 of the equal diameter part = the arc length C of the equal diameter part * the internal area width d of the equal diameter part; the internal area S2 of the deformation part is measured by the area calculation function of the drawing software.

[0011] By adopting the above technical solution and using the area segmentation method, the internal area of ​​the hose is divided into an equal-diameter part and a deformation part, and the areas of the two parts are measured and calculated respectively, thereby realizing the calculation of the equivalent flow area.

[0012] Preferably, the arc length C of the equal diameter section is measured by the arc length calculation function of the drawing software.

[0013] By adopting the above technical solution, through drawing software such as AUTOCAD, using the size calculation function in the software, the automatic measurement of the pitch arc length C can be achieved, which greatly reduces the calculation intensity and can ensure high accuracy.

[0014] Preferably, the equivalent flow area S is measured by a regional area calculation function of a drawing software.

[0015] By adopting the above technical solution, through drawing software such as AUTOCAD, using the area query calculation function in the software, the automatic measurement of the equivalent flow area S can be achieved, which greatly reduces the calculation intensity and can ensure high accuracy.

[0016] Preferably, the shape of the inner area of ​​the deformation part is simplified into a triangle, and the three vertices of the triangle are respectively the tip formed by the deformation part being squeezed by the roller, the junction between the inner circle of the deformation part and the inner circle of the equal-diameter part, and the junction between the outer circle of the deformation part and the outer circle of the equal-diameter part; The internal area of ​​the deformation part S2 = triangle base * triangle height / 2.

[0017] By adopting the above technical solution, through this method, there is no need to rely on the automatic dimension calculation function of the drawing software, and the internal area S2 of the deformation part can be manually estimated. In addition, the internal area S1 of the equal-diameter part can also be manually measured and calculated. Therefore, this method is suitable for work scenarios such as production sites that require rapid estimation of the theoretical flow rate of the peristaltic pump, and the calculation accuracy is still close to 90%.

[0018] Preferably, a chamfer is provided at the junction between the equal diameter portion and the deformation portion, and the equivalent flow area is measured.

[0019] By adopting the above technical solution, the rounded setting can make the drawn hose figure closer to the actual working hose shape, thereby effectively improving the calculation accuracy of the peristaltic pump theoretical flow rate.

[0020] Preferably, the rounding radius is larger than the roller radius and smaller than the inner circle radius of the annular hose.

[0021] By adopting the above technical solution, the larger the fillet radius is, the higher the calculation accuracy of the theoretical flow rate will be, and the staff can adopt different fillet radii according to actual needs.

[0022] In summary, the present invention includes at least one of the following beneficial technical effects: 1. This application can effectively reduce the influence of hose deformation on the calculation accuracy when calculating the theoretical flow of the peristaltic pump by making the circular cross section of the hose equivalent to a rectangle with equal area, and by calculating the area of ​​the inner area of ​​the annular hose as the equivalent flow area S, so that the calculation of the theoretical flow has a higher accuracy, and the calculation accuracy can be maintained at about 90% or above 90%; 2. This application can use drawing software to draw the theoretical shape of the hose, which is equivalent to the shape of the hose when it is actually working, and use the automatic calculation function of the size and area of ​​the drawing software to accurately calculate the theoretical flow rate of the peristaltic pump; 3. The equivalent flow area S in this application can also be obtained by manual measurement and calculation, so it is suitable for work scenarios such as production sites where the theoretical flow of peristaltic pumps needs to be quickly estimated, and the calculation accuracy is still close to 90%; 4. This application has a wide range of applicability and can be applied to multiple peristaltic pump series. More than a dozen products were tested during the actual experiment. In the same product, even if the pipe diameter, pipe material and rotation speed change, only the parameters need to be modified for drawing to obtain a higher theoretical flow calculation accuracy, and the calculation error can be controlled within 10%. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is the theoretical shape of the hose and roller in Example 1 of the present application; Figure 2 It is a schematic diagram showing that the circular cross section of the hose in Example 1 of the present application is equivalent to a rectangle; Figure 3 is a schematic diagram of the shape of the equivalent flow area of ​​the hose in Example 1 of the present application; Figure 4 It is a schematic diagram of the size parameters of the KFS peristaltic pump using a brushless DC motor in the verification example in Example 1 of the present application; Figure 5 It is a schematic diagram of the size parameters of the KFS peristaltic pump using a stepper motor in the verification example in Example 1 of the present application; Figure 6 It is a schematic diagram of the shape of the equivalent flow area when the rounding radius is 4.6 mm in Example 2 of the present application; Figure 7 It is a schematic diagram of the shape of the equivalent flow area when the rounding radius is 14 mm in Example 2 of the present application; Figure 8 It is a schematic diagram of the shape of the equivalent flow area when the rounding radius is infinite in Example 2 of the present application; Fig. 9 This is a schematic diagram of the shapes of the inner area of ​​the equal-diameter part and the inner area of ​​the deformation part when the area segmentation method is adopted in Example 3 of the present application.

[0024] Markings in the attached drawings: 1, hose; 11, equal diameter portion; 12, deformation portion; 13, chamfer; 2, roller. DETAILED DESCRIPTION

[0025] The following is combined with Figure 1-9 The present invention is described in further detail.

[0026] In the actual operation of the peristaltic pump, the roller extrusion of the hose is a complex nonlinear dynamic problem involving fluid-solid coupling, which is difficult to quantify. In terms of processing accuracy, assembly and installation, and even when the working conditions change, this extrusion is an unknown quantity that is extremely easy to change. Therefore, for the calculation of the theoretical flow of the peristaltic pump, the conventional method currently used is difficult to fully consider the impact of the hose extrusion on the flow calculation results, so the accuracy is usually not high.

[0027] The embodiment of the present application discloses a method for calculating the theoretical flow rate of a peristaltic pump, which effectively improves the calculation accuracy of the theoretical flow rate by optimizing the squeezing condition of the hose 1 .

[0028] Example 1 The present application embodiment discloses a method for calculating the theoretical flow rate of a peristaltic pump, which specifically includes the following steps: Step 1: Reference Figure 1 , measure the following parameters of the peristaltic pump: inner diameter D of the pump housing, inner diameter d of hose 1, wall thickness δ of hose 1, diameter R and number A of rollers 2, radius L of the circle where the center of roller 2 is located, and motor speed n; Step 2: Reference Figure 2 For the convenience of calculation, the circular cross section of the hose 1 can be simplified to be equivalent to a rectangle with equal area. The width of the rectangle is d, and its height can be expressed as: Step 3: Reference Figure 1 , according to the size data measured in step 1, the hose 1 and the roller 2 are drawn respectively, and the theoretical shape of the hose 1 after being squeezed by the roller 2 when the peristaltic pump is working is obtained to simulate the actual squeezing condition of the hose 1; When drawing the theoretical shapes of the hose 1 and the roller 2, it is necessary to ensure that the hose 1 is annular as a whole, and its outer ring diameter is equal to the inner diameter D of the pump housing; the roller 2 is arranged inside the hose 1 and squeezes the hose 1. The part of the hose 1 between two adjacent rollers 2, the part not squeezed by the roller 2 is the equal diameter part 11, and the squeezed part is the deformation part 12, and the deformation part 12 has an arc-shaped depression and fits with the surface of the roller 2.

[0029] Step 4: Reference Figure 3 , based on the theoretical shape of the hose 1 obtained in step 3, measure the area of ​​the inner region of the hose 1, that is, the area of ​​the shaded part, and use it as the equivalent flow area S of the hose 1; Step 5: The internal volume of the hose 1 is obtained by multiplying the equivalent flow area by the height of the rectangle, and the theoretical flow rate of the peristaltic pump is calculated based on this, and the formula is: V = n*S*h.

[0030] The following uses the KFS peristaltic pump of Kachuaner Fluid Technology (Shanghai) Co., Ltd. (the specific model of the peristaltic pump is: KFS-HD1S06W, its motor uses a brushless DC motor, and the speed is not adjustable) as a specific example to further verify the calculation results and accuracy of the above formula: The inner diameter of the pump casing of the peristaltic pump is D=28mm, the hose 1 is a BPT tube, the inner diameter of the hose 1 is d=2mm, the wall thickness of the hose 1 is δ=1mm, the diameter of the roller 2 is R=9.20mm, the number of rollers 2 is A=3, the radius of the circle where the center of the roller 2 is located is L=7.75mm, and the rated speed of the motor is n=450rpm.

[0031] Reference Figure 4 , draw the hose 1 and roller 2 respectively with the above dimensions, and simulate the situation where the hose 1 is squeezed by the roller 2.

[0032] The shaded area is the effective flow area after the roller 2 squeezes the hose 1. The total effective area is 32.66*3=97.98mm 2 ; The specific method for measuring the area of ​​the shadow region is: using AUTOCAD drawing software to draw the hose 1 and the roller 2. And through the area query function of the drawing software, the area of ​​the shadow region can be directly measured.

[0033] In addition, drawing software such as SOLIDWORKS may be used to draw the hose 1 and the roller 2, which can also achieve the purpose of measuring the area of ​​the shadow region.

[0034] The circular cross section of the hose 1 is equivalent to a rectangle of equal area, with the width equal to the inner diameter d = 2 mm, and the height is h = πd / 4 = 1.57 mm; The theoretical flow rate of the peristaltic pump is: V=n*S*h=450rpm*1.57mm*97.98mm 2 =69.22ml / min To measure the actual flow rate of the peristaltic pump, the steps are as follows: 1. Connect the hose to the peristaltic pump and impose certain constraints to prevent violent shaking that may occur during high-speed operation; 2. The power driver provides voltage and current to the peristaltic pump. The peristaltic pump extracts liquid from a larger measuring cup and discharges the liquid into another smaller measuring cup. The smaller measuring cup is placed on an electronic balance. 3. Before each experiment, determine the peristaltic pump speed n, and select the "peel" function on the electronic balance to reset the setting, press the start button, the peristaltic pump starts working, and the pump stops working after one minute, and the timing ends; 4. Since the density of water is 1g / cm 3, so the reading on the electronic balance at this time is the actual flow rate of the peristaltic pump under the pipe material, pipe diameter and speed; 5. Repeat this experimental process 5 times without changing the working conditions and equipment. Discard the maximum and minimum extreme values ​​of the measured data and take the average of the remaining 3 valid values ​​as the final data of the flow experiment.

[0035] The actual flow rate of the peristaltic pump is 65.03 ml / min, so the calculation accuracy is: 65.03 / 69.22=93.95%.

[0036] The calculation accuracy deviation is within 10%.

[0037] Due to the different motor speeds, the extrusion of the hose will also change. In addition, the deformation state of hoses made of different materials under the same conditions is slightly different. In addition, since the speed of the above-mentioned KFS peristaltic pump (DC brushless motor) is not adjustable, the KFS peristaltic pump (the motor is a stepper motor with adjustable speed) of Kachuaner Fluid Technology (Shanghai) Co., Ltd. is replaced. Taking the peristaltic pump as a specific example, the theoretical flow rate is calculated at different motor speeds and when using hoses of different materials, and the calculation accuracy is obtained: The specific parameters of the peristaltic pump are: inner diameter of the pump casing D = 27.8mm, inner diameter of hose 1 d = 1mm, wall thickness of hose 1 δ = 1mm, diameter of roller 2 R = 9.3mm, number of rollers 2 A = 3, radius of the circle where the center of roller 2 is located L = 7.75mm, rated speed of the motor n = 250rpm, and speed regulation range of 50rpm≦n≦300rpm.

[0038] Reference Figure 5 , draw the hose 1 and roller 2 respectively with the above dimensions, and simulate the situation where the hose 1 is squeezed by the roller 2.

[0039] The shaded area is the effective flow area after the roller 2 squeezes the hose 1. The total effective area is 17.93*3=53.79mm 2 ; The specific method for measuring the area of ​​the shadow region is: using AUTOCAD drawing software to draw the hose 1 and the roller 2. And through the area query function of the drawing software, the area of ​​the shadow region can be directly measured.

[0040] In addition, drawing software such as SOLIDWORKS may be used to draw the hose 1 and the roller 2, which can also achieve the purpose of measuring the area of ​​the shadow region.

[0041] The circular cross section of the hose is simplified to be equivalent to a rectangle with equal area. The width of the rectangle is d, and its height is h = πd / 4 = 3.14*1 / 4 = 0.785 mm.

[0042] The theoretical flow rate of the peristaltic pump is: V=n*S*h=n*0.785*53.79=n*4.22(ml / min) This application takes two types of hoses made of BPT and silicone as examples to calculate the theoretical flow rate and calculation accuracy of the KFS peristaltic pump at different speeds when using these two types of hoses. For specific data, see Table 1.

[0043] Table 1 Since the hose 1 of the peristaltic pump has different diameters, the deformation after being squeezed will also be slightly different. And since the above-mentioned peristaltic pumps (DC brushless type and stepper motor type) are not convenient for replacing hoses of different sizes, this application uses the KPAS-100 peristaltic pump designed and produced by Kachuaner Fluid Technology (Shanghai) Co., Ltd. as a specific example to calculate the theoretical flow, actual flow and theoretical flow calculation accuracy of the peristaltic pump when using hoses of different diameters and at different motor speeds. The inner diameter of the pump housing of the peristaltic pump is D = 32.8mm, the diameter of the roller 2 is R = 8.3mm, the number of rollers 2 is A = 3, the radius of the circle where the center of the roller 2 is located is L = 9.93mm, the rated speed of the motor is n = 350rpm, the material of the hose 1 is BPT, and the hose 1 adopts three different sizes, specifically: 1. Hose size: inner diameter 1.6mm, outer diameter 4.8mm; see Table 2 for theoretical flow calculation accuracy.

[0044] Table 2 2. Hose size: inner diameter 2.4mm, outer diameter 5.6mm; see Table 3 for theoretical flow calculation accuracy.

[0045] Table 3 3. Hose size: inner diameter 3.2mm, outer diameter 6.4mm; see Table 4 for theoretical flow calculation accuracy.

[0046] Table 4 From Tables 1-4, it can be seen that the application is very widely applicable and can be applied to multiple peristaltic pump series. More than a dozen products were tested during the actual experiment. In the same product, even if the pipe diameter, pipe material and rotation speed change, only the parameters need to be modified for drawing to obtain a higher theoretical flow calculation accuracy, and the calculation error can be controlled within 10%.

[0047] Example 2 The embodiment of the present application takes the KFS peristaltic pump (specific model of the peristaltic pump is: KFS-HD1S06W, whose motor adopts a brushless DC motor and whose speed is not adjustable) produced by Kachuaner Fluid Technology (Shanghai) Co., Ltd. as a specific example: The inner diameter of the pump casing of the peristaltic pump is D=28mm, the hose 1 is a silicone tube, the inner diameter of the hose 1 is d=2mm, the wall thickness of the hose 1 is δ=1mm, the diameter of the roller 2 is R=9.20mm, the number of rollers 2 is A=3, the radius of the circle where the center of the roller 2 is located is L=7.75mm, and the rated speed of the motor is n=450rpm.

[0048] Example 2 of the present application discloses a method for calculating the theoretical flow rate of a peristaltic pump, and based on Example 1, the theoretical shape of the hose 1 is optimized and improved, thereby further improving the calculation accuracy of the theoretical flow rate.

[0049] Specifically, a chamfer 13 is provided at the junction of the equal diameter portion 11 and the deformation portion 12 to make the theoretical shape of the hose 1 closer to the shape in actual operation. And the radius T of the chamfer 13 is not less than the radius of the roller 2 .

[0050] Continue to use the peristaltic pump parameters in Example 1 as verification: Reference Figure 6 When the radius of fillet 13 T = roller 2 radius = 4.6 mm, the equivalent flow area S, i.e. the area of ​​the shaded area, is also measured using AUTOCAD drawing software: S=32.43*3=97.29mm 2 Then the theoretical flow rate of the peristaltic pump is: V=n*S*h=68.73ml / min The actual flow rate of the peristaltic pump is 65.03 ml / min, so the calculation accuracy is: 65.03 / 68.73 = 94.61% Reference Figure 7 When the radius of fillet 13 T = the outer radius of hose 1 = the radius of pump casing = 14 mm, the equivalent flow area S, i.e. the area of ​​the shaded area, is also measured using AUTOCAD drawing software: S=31.93*3=95.79mm 2 Then the theoretical flow rate of the peristaltic pump is: V=n*S*h=67.67ml / min The actual flow rate of the peristaltic pump is 65.03ml / min, so the calculation accuracy is: 65.03 / 67.67=96.1% Reference Figure 8When the radius T of the chamfer 13 approaches infinity, the shape of the chamfer 13 is close to a straight line. When drawing the chamfer 13, a straight line tangent to both the equal diameter portion 11 and the deformed portion 12 can be directly drawn. At this time, the equivalent flow area S, i.e. the area of ​​the shaded area, is also measured using AUTOCAD drawing software: S=30.88*3=92.64mm 2 Then the theoretical flow rate of the peristaltic pump is: V=n*S*h=65.45ml / min The actual flow rate of the peristaltic pump is 65.03 ml / min, so the calculation accuracy is: 65.03 / 65.45 = 99.35% Example 3 The embodiment of the present application takes the KFS peristaltic pump (specific model of the peristaltic pump is: KFS-HD1S06W, whose motor adopts a brushless DC motor and whose speed is not adjustable) produced by Kachuaner Fluid Technology (Shanghai) Co., Ltd. as a specific example: The inner diameter of the pump casing of the peristaltic pump is D=28mm, the hose 1 is a silicone tube, the inner diameter of the hose 1 is d=2mm, the wall thickness of the hose 1 is δ=1mm, the diameter of the roller 2 is R=9.20mm, the number of rollers 2 is A=3, the radius of the circle where the center of the roller 2 is located is L=7.75mm, and the rated speed of the motor is n=450rpm.

[0051] Example 2 of the present application discloses a method for calculating the theoretical flow rate of a peristaltic pump, and based on Example 1, the theoretical shape of the hose 1 is optimized and improved, thereby further improving the calculation accuracy of the theoretical flow rate.

[0052] Specifically, the area of ​​the shadow region inside the hose 1, that is, the equivalent flow area, can be calculated by using a region segmentation method in addition to measuring using two-dimensional or three-dimensional drawing software.

[0053] The specific steps are: Reference Fig. 9 , the equivalent flow area S = the internal area S1 of the hose 1 between two adjacent rollers 2 * the number A of rollers 2.

[0054] The inner area S1 of the hose 1 between two adjacent rollers 2 = the inner area S2 of the equal-diameter portion 11 + the inner area S3 of the deformation portion 12 * 2.

[0055] Since the width of the equal diameter portion 11 is equal to the inner diameter d of the hose 1 = 2 mm, it is only necessary to measure and calculate the pitch arc length C of the equal diameter portion 11 by manual measuring tools such as a protractor and a ruler, and the internal area S2 of the equal diameter portion 11 can be obtained by the formula S2 = 2*C. Preferably, the pitch arc length C can also be calculated and measured by the dimension measurement function in the drawing software.

[0056] As for the calculation of the internal area S3 of the deformation part 12, two-dimensional or three-dimensional drawing software can be used for measurement, or the area can be simplified into a triangle. The three vertices of the triangle are the tip formed by the deformation part 12 being squeezed by the roller 2, the connection between the inner circle of the deformation part 12 and the inner circle of the equal-diameter part 11, and the connection between the outer circle of the deformation part 12 and the outer circle of the equal-diameter part 11. Use a manual measuring tool to measure the base and height of the triangle respectively, and the approximate area of ​​the internal area S3 of the deformation part 12 can be calculated.

[0057] Continue to use the peristaltic pump parameters in Example 1 as verification: Referring to Figure 9, the length of the bottom side of the inner area of ​​the deformation portion 12 = d = 2 mm, and the height of the inner area of ​​the deformation portion 12 is measured by a manual measuring tool such as a ruler or a vernier caliper = 3.9 mm, so the area of ​​the inner area of ​​the deformation portion 12 S3 = 3.9 mm 2 At the same time, after measurement, the arc length of the equal diameter part 11 is 13.15mm, so the internal area of ​​the equal diameter part 11 is S2 = 13.15*2 = 26.3mm 2 .

[0058] Therefore, the equivalent flow area S = (26.3 + 3.9 * 2) * 3 = 102.3 mm 2 .

[0059] V=n*S*h=450rpm*1.57mm*102.3mm 2 =72.27ml / min The actual flow rate of the peristaltic pump is 65.03 ml / min, so the calculation accuracy is: 65.03 / 72.27 = 89.98% Although the calculation accuracy is low, it is still close to 90%. However, since the above calculation method does not require the use of drawing software, the staff can use manual drawing and measure various parameters through manual measuring tools. It is suitable for rapid estimation of the theoretical flow rate of the peristaltic pump at the production site, and the calculation accuracy is still close to 90%.

[0060] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for calculating the theoretical flow rate of a peristaltic pump, characterized in that: The following steps are involved: Step 1: Measure the following parameters of the peristaltic pump: inner diameter D of the pump housing, inner diameter d of the hose (1), wall thickness δ of the hose (1), diameter R of the roller (2), radius L of the circle where the center of the roller (2) is located, and motor speed n; Step 2: The circular cross section of the hose (1) is equivalent to a rectangle with the same area. The height of the rectangle is d, and the width is h=πd / 4; Step 3: Using the parameters in step 1, draw a theoretical shape of the hose (1) after being squeezed by the roller (2); the hose (1) is arranged in a circular ring shape, the outer diameter of the ring hose (1) is equal to the inner diameter D of the pump casing, and the roller (2) is arranged on the inner side of the hose (1); the hose (1) includes a constant diameter portion (11) and a deformation portion (12), and the deformation portion (12) has an arc-shaped depression and is in contact with the surface of the roller (2); Step 4: In the theoretical shape of the hose (1), measure the area of ​​the inner region of the annular hose (1) as the equivalent flow area S; Step 5: Calculate the theoretical flow rate of the peristaltic pump: V=n*S*h.

2. The method for calculating the theoretical flow rate of a peristaltic pump according to claim 1, characterized in that: The number of rollers (2) is A, then the internal area S1 of the hose (1) between two adjacent rollers (2) = the equivalent flow area S / A = the internal area S2 of the equal diameter portion (11) + the internal area S3 of the deformation portion (12) * 2; The internal area S1 of the equal diameter portion (11) = the arc length C of the equal diameter portion (11) * the internal area width d of the equal diameter portion (11); the internal area S2 of the deformation portion (12) is measured by using the area calculation function of the drawing software.

3. The method for calculating the theoretical flow rate of a peristaltic pump according to claim 2, characterized in that: The pitch arc length C of the equal diameter portion (11) is measured by using the arc length calculation function of the drawing software.

4. The method for calculating the theoretical flow rate of a peristaltic pump according to claim 1, characterized in that: The shape of the inner region of the deformation part (12) is simplified into a triangle, and the three vertices of the triangle are respectively the tip of the deformation part (12) formed by the extrusion of the roller (2), the junction between the inner circle of the deformation part (12) and the inner circle of the equal-diameter part (11), and the junction between the outer circle of the deformation part (12) and the outer circle of the equal-diameter part (11); The internal area of ​​the deformation part (12) is S2 = triangle base * triangle height / 2.

5. The method for calculating the theoretical flow rate of a peristaltic pump according to claim 1, characterized in that: The equivalent flow area S is measured by the area calculation function of the drawing software.

6. The method for calculating the theoretical flow rate of a peristaltic pump according to claim 1, characterized in that: A chamfer (13) is provided at the junction of the equal diameter portion (11) and the deformation portion (12), and the equivalent flow area is measured.

7. The method for calculating the theoretical flow rate of a peristaltic pump according to claim 6, characterized in that: The radius T of the chamfer (13) is greater than the radius of the roller (2).

Images