Anti-reflux control method for peristaltic pump

Abstract

This application relates to a peristaltic pump anti-backflow control method, comprising the following steps: obtaining the current flow rate and direction at the outlet of the pump assembly; controlling the pump assembly based on the current flow rate and direction, and the expected flow rate of the pump assembly in the current operating state; the peristaltic pump anti-backflow control method of this application determines whether liquid backflow occurs in the pump assembly by real-time detection of the liquid flow rate at the outlet of the pump assembly; when liquid backflow occurs in the pump assembly in the stopped state, the pump assembly can be controlled to deliver liquid to the outlet so that the extra delivered liquid can offset the backflow liquid; when liquid backflow occurs in the pump assembly in the running state, the liquid flow rate at the outlet of the pump assembly can be adjusted by adjusting the pump assembly speed, so that the actual flow rate at the outlet of the pump assembly matches the preset value, achieving the expected outlet flow rate, thereby solving the liquid backflow problem of the pump assembly in the running state.

Description

Technical Field

[0001] This application relates to the field of peristaltic pump technology, and in particular to a method for preventing backflow in peristaltic pumps. Background Technology

[0002] A peristaltic pump is a positive displacement pump that pushes gas or liquid forward by squeezing an elastic tubing and uses the local vacuum created when the tubing recovers its elasticity to draw in the liquid or gas behind it. It pumps gas or liquid by alternately squeezing and releasing the elastic tubing.

[0003] However, during operation, peristaltic pumps are prone to insufficient clamping force, which can prevent the hose from sealing completely and lead to liquid backflow. Furthermore, if the peristaltic pump cannot maintain proper clamping of the flexible hose when it is stopped, liquid backflow can also occur.

[0004] Currently, most solutions to the problem of fluid backflow in peristaltic pumps involve adding a check valve or altering the shape of the top block to increase the compression deformation of the flexible hose. However, check valves only solve the backflow problem when the peristaltic pump is stopped, and increasing the compression deformation of the flexible hose increases the risk of hose wear and affects the service life of the peristaltic pump. Summary of the Invention

[0005] Therefore, it is necessary to provide a peristaltic pump anti-backflow control method to address the problem that peristaltic pumps are prone to liquid backflow during both operation and shutdown.

[0006] A method for preventing backflow in a peristaltic pump includes the following steps:

[0007] Obtain the current flow rate and direction at the outlet of the pump assembly;

[0008] The pump assembly is controlled based on the current flow rate and direction, as well as the expected flow rate of the pump assembly in the current operating state.

[0009] In one embodiment, controlling the pump assembly based on the current flow rate and flow direction, and the expected flow rate of the pump assembly in the current operating state, includes:

[0010] When the pump assembly is in a stopped state, if the current flow rate is greater than 0 and the fluid flow direction is from the outlet to the inlet, the pump assembly is controlled to deliver fluid to the outlet, and the flow rate of the delivered fluid is equal to the current flow rate.

[0011] When the pump assembly is in operation, the rotational speed of the pump assembly is controlled according to the current flow rate and the set flow rate of the pump assembly in the current operating state, so as to adjust the current flow rate to be consistent with the set flow rate.

[0012] In one embodiment, when the pump assembly is in operation, controlling the rotational speed of the pump assembly based on the current flow rate and a set flow rate value for the pump assembly in the current operating state, so as to adjust the current flow rate to be consistent with the set flow rate value, includes:

[0013] If the current flow rate is less than the set flow rate, the pump assembly is controlled to increase its rotational speed until the current flow rate matches the set flow rate.

[0014] If the current flow rate is greater than the set flow rate, the pump assembly is controlled to reduce its rotational speed until the current flow rate matches the set flow rate.

[0015] In one embodiment, obtaining the current flow rate and direction at the outlet of the pump assembly includes:

[0016] The measured flow rate value is obtained at a first preset time interval;

[0017] The average of multiple measured flow rates within the time period of one revolution of the pump head of the pump body assembly is calculated to obtain the current flow rate value.

[0018] In one embodiment, obtaining the current flow rate and direction at the outlet of the pump assembly includes:

[0019] The current flow rate and direction are obtained using a non-contact flow sensor.

[0020] The pump body assembly has a flexible pump tube, which has an inlet and an outlet, and the non-contact flow sensor is mounted on the outlet.

[0021] In one embodiment, the peristaltic pump backflow prevention control method further includes:

[0022] Obtain the liquid pressure value at the outlet of the pump body assembly;

[0023] When the liquid pressure reaches the set pressure value, the rotational speed of the pump assembly is maintained or reduced.

[0024] In one embodiment, the set pressure value is less than or equal to the rated pressure of the pump body assembly.

[0025] In one embodiment, obtaining the liquid pressure value at the outlet of the pump assembly includes:

[0026] The measured pressure value is obtained at a second preset time interval;

[0027] The average of multiple measured pressure values ​​is calculated over a time period during which the pump head of the pump body assembly rotates one revolution to obtain the liquid pressure value.

[0028] In one embodiment, obtaining the liquid pressure value at the outlet of the pump assembly includes:

[0029] The liquid pressure value is obtained using a non-contact pressure sensor;

[0030] The pump body assembly has a flexible pump tube, which has an inlet and an outlet, and the non-contact pressure sensor is mounted on the outlet.

[0031] In one embodiment, the peristaltic pump backflow prevention control method further includes:

[0032] Obtain the measured rate value of the pump body assembly;

[0033] When the measured rate value reaches the set rate value, the rotational speed of the pump assembly is maintained or reduced.

[0034] The aforementioned peristaltic pump backflow prevention control method detects the liquid flow rate at the pump assembly outlet in real time to determine whether liquid backflow has occurred. When liquid backflow occurs while the pump assembly is stopped, the method controls the pump assembly to continue supplying liquid to the outlet, ensuring that the supplied liquid value matches the detected flow rate. This allows the excess supplied liquid to offset the backflow, thus resolving the liquid backflow problem when the pump assembly is stopped. When liquid backflow occurs while the pump assembly is running, the liquid flow rate at the pump assembly outlet can be adjusted by regulating the pump assembly speed. This ensures that the actual flow rate at the pump assembly outlet matches the preset value, achieving the expected outlet flow rate and resolving the liquid backflow problem when the pump assembly is running. Attached Figure Description

[0035] Figure 1 This is a flowchart illustrating a peristaltic pump backflow prevention control method according to some embodiments of this application.

[0036] Figure 2 This is a schematic diagram of the pump body assembly according to some embodiments of this application.

[0037] Figure label:

[0038] 1. Flow sensor; 2. Pressure sensor; 3. Pump body assembly; 31. Housing; 32. Pump head; 33. Flexible pump tube; 34. Roller. Detailed Implementation

[0039] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0040] A peristaltic pump is a type of positive displacement pump, also known as a hose pump or flexible tube pump. A peristaltic pump uses rollers or a top block to squeeze a flexible tube, propelling gas or liquid forward within the tube. It then utilizes the localized vacuum created when the tube recovers its elasticity to draw in the remaining liquid or gas. Continuous pumping of gas or fluid is achieved through the alternating squeezing and releasing of the flexible tube. With a constant diameter of flexible tube, the speed at which the rollers or top block push the tube determines the volume of liquid transported; the faster the pushing speed, the greater the liquid flow rate.

[0041] Peristaltic pumps are prone to liquid backflow during operation or when stopped. Currently, there are two main solutions to this problem. One is to use a check valve, which involves installing an expandable inner tube inside the flexible hose and attaching a pressure control valve component and a check valve to both ends of the inner tube, thus controlling the direction of liquid flow. The other is to modify the shape of the roller or top block, by adding protruding ribs to the outer surface of the roller or top block. When the hose is squeezed, the small contact area between the ribs and the hose allows for a higher clamping force, effectively controlling liquid backflow.

[0042] However, both of the above solutions reduce fluid backflow through mechanical structures. While using a check valve can prevent fluid backflow in the peristaltic pump when it is stopped, the back pressure at the check valve outlet can still cause fluid backflow during the compression process. Therefore, the check valve design is only suitable for suppressing backflow when the peristaltic pump is stopped. Changing the shape of the rollers or top block actually increases the amount of compression deformation on the peristaltic pump's flexible hose. Although this method can achieve backflow prevention in both stopped and compression states, it also increases the wear and tear on the flexible hose. That is, the increased compression deformation on the flexible hose leads to greater compressive stress on the hose, resulting in increased wear and tear on the flexible hose over the same operating time, increasing the risk of hose damage and thus affecting the service life of the peristaltic pump.

[0043] In summary, there is an urgent need for a peristaltic pump backflow prevention control method to solve the problem that the backflow prevention effect and the lifespan of the flexible hose cannot be guaranteed simultaneously when the peristaltic pump is running or stopped.

[0044] See Figures 1-2 One embodiment of this application provides a peristaltic pump backflow prevention control method, including the following steps:

[0045] Obtain the current flow rate and direction at the outlet of pump body assembly 3;

[0046] Based on the current flow rate and direction, and the expected flow rate of pump assembly 3 under the current operating condition, the pump assembly 3 is controlled.

[0047] Specifically, the flow sensor 1 detects the flow rate and direction of the liquid at the outlet of the pump assembly 3. The pump assembly 3 includes a flexible pump tube 33, which has an inlet and an outlet. During use, the liquid flows from the inlet to the outlet. The flow sensor 1 is installed on the outlet to detect the flow rate and direction of the liquid at the outlet of the pump assembly 3, obtaining the detected flow rate value L1 and the detected liquid direction.

[0048] In implementation, the aforementioned peristaltic pump backflow prevention control method uses flow sensor 1 to detect the liquid flow rate and direction at the outlet of pump assembly 3 in real time to determine whether liquid backflow has occurred. When liquid backflow occurs in pump assembly 3 while it is stopped, the system controls pump assembly 3 to continue supplying liquid to the outlet, ensuring the supplied liquid value matches the detected flow rate. This allows the excess supplied liquid to offset the backflow, thus resolving the liquid backflow problem in the stopped state. When liquid backflow occurs in pump assembly 3 while it is running, the liquid flow rate at the outlet of pump assembly 3 can be adjusted by regulating the pump assembly 3's rotational speed. This matches the actual flow rate at the outlet with a preset value, achieving the expected outlet flow rate and resolving the liquid backflow problem in the running state.

[0049] In one embodiment, the pump assembly is controlled based on the current flow rate and direction, and the expected flow rate of the pump assembly 3 in the current operating state, including:

[0050] When the pump assembly 3 is in a stopped state, if the current flow rate is greater than 0 and the fluid flow direction is from the outlet to the inlet, the pump assembly 3 is controlled to deliver fluid to the outlet, and the flow rate of the delivered fluid is equal to the current flow rate.

[0051] Specifically, when pump assembly 3 is in a stopped state, the expected flow rate is 0. If the detected flow rate value L1 is greater than 0, and the detected liquid flow direction is from the outlet to the inlet, then liquid backflow can be determined to have occurred. At this time, pump assembly 3 is controlled to operate and deliver liquid to the outlet so that the delivered liquid can offset the backflowing liquid. To ensure the offsetting effect, the amount of liquid delivered is consistent with the detected flow rate value L1.

[0052] When the pump assembly is in operation, the speed of the pump assembly is controlled based on the current flow rate and the set flow rate for the pump assembly in the current operating state, so as to adjust the current flow rate to match the set flow rate.

[0053] Specifically, when the pump assembly 3 is in operation, the detected flow rate value L1 is compared with the set flow rate value L2. The set flow rate value L2 is the expected flow rate delivered by the pump assembly 3.

[0054] If the detected flow rate value L1 is less than the set flow rate value L2, it can be determined that liquid backflow has occurred. At this time, the pump assembly 3 is controlled to increase its rotation speed to increase the amount of liquid delivered by the pump assembly 3 to the outlet; wherein, the increased liquid amount is the difference between the detected flow rate value L1 and the set flow rate value L2.

[0055] For example, pump assembly 3 is expected to deliver 10 ml of liquid in 10 seconds, so the initial rotational speed of pump assembly 3 can be set to 1 ml / s. When pump assembly 3 has been running for 5 seconds, the expected flow rate is 5 ml, that is, the flow rate value L2 set for the 5th second is 5 ml. If the detected flow rate value L1 is 4 ml at this time, it indicates that 1 ml of liquid has flowed back. Pump assembly 3 can increase the amount of liquid delivered to the outlet by increasing the rotational speed. The increased liquid amount is the difference between L1 and L2, which is 1 ml. That is, pump assembly 3 needs to deliver an additional 1 ml of liquid to the outlet to offset the 1 ml of backflow.

[0056] If the detected flow rate value L1 is greater than the set flow rate value L2, it can be determined that excessive liquid delivery has occurred. At this time, the pump assembly 3 is controlled to reduce its speed to reduce the amount of liquid delivered by the pump assembly 3 to the outlet section; wherein, the amount of liquid reduced is the difference between the detected flow rate value L1 and the set flow rate value L2.

[0057] For example, pump assembly 3 is expected to deliver 10 ml of liquid in 10 seconds, so the initial rotation speed of pump assembly 3 can be set to 1 ml / s. When pump assembly 3 has been running for 5 seconds, the expected flow rate is 5 ml, that is, the flow rate value L2 set for the 5th second is 5 ml. If the detected flow rate value L1 is 6 ml at this time, it means that 1 ml of liquid has been delivered excessively. Pump assembly 3 can reduce the amount of liquid delivered to the outlet by reducing its rotation speed. The amount of liquid reduced is the difference between L1 and L2, which is 1 ml. That is, pump assembly 3 needs to deliver 1 ml less liquid to the outlet to offset the 1 ml of liquid delivered excessively.

[0058] In one embodiment, the peristaltic pump anti-backflow control method of this application further includes: acquiring the flow rate value and liquid flow direction detected by the flow sensor 1 through the control system, and controlling the pump body assembly 3 according to the acquired detected flow rate value and liquid flow direction.

[0059] Specifically, the control system is electrically connected to the flow sensor 1 and the pump assembly 3. After detecting the flow rate and direction of the liquid at the outlet of the pump assembly 3, the flow sensor 1 can transmit the detected flow rate value L1 and the detected liquid flow direction to the control system.

[0060] When pump assembly 3 is in a stopped state, the control system can determine whether liquid backflow has occurred based on the detected flow rate value L1 and the detected liquid flow direction. When the control system determines that liquid backflow has occurred, it can control pump assembly 3 to run and deliver liquid to the outlet. The amount of liquid delivered is consistent with the detected flow rate value L1, so that the delivered liquid can offset the backflowing liquid.

[0061] When pump assembly 3 is in operation, the control system compares the detected flow rate value L1 with the set flow rate value L2 to determine whether liquid backflow or excessive liquid delivery has occurred. If the control system determines that liquid backflow has occurred, it can increase the speed of pump assembly 3 to increase the amount of liquid delivered to the outlet, thereby offsetting the backflow. If the control system determines that excessive liquid delivery has occurred, it can decrease the speed of pump assembly 3 to reduce the amount of liquid delivered to the outlet, thereby offsetting the excessive liquid delivery.

[0062] In one embodiment, obtaining the current flow rate and direction at the outlet of the pump assembly includes:

[0063] The measured flow rate value is obtained at a first preset time interval;

[0064] The average of multiple measured flow rates within the time period of one revolution of the pump head of the pump body assembly is calculated to obtain the current flow rate. The current flow rate is the measured flow rate L1 mentioned above.

[0065] Specifically, the pump head 32 is rotatably mounted on the housing 31 and is connected to the driver, which drives the pump head 32 to rotate on the housing 31. Along the axial direction of the pump head 32, at least three rollers 34 are evenly distributed on its outer circumferential surface. The rollers 34 are located inside the housing 31, and a pressure tube gap is provided between them and the inner wall of the housing 31. The flexible pump tube 33 is embedded in the pressure tube gap and abuts against the pressure tube gap and the rollers 34. At least two openings are provided on the housing 31, through which the inlet and outlet portions of the flexible pump tube 33 extend to the outside of the housing 31.

[0066] When the pump body assembly 3 is running, the control system can send a signal to the driver, causing the driver to drive the pump head 32 and roller 34 to rotate, thereby alternately squeezing and releasing the flexible pump tube 33, so that the liquid can be pumped into the flexible pump tube 33 through the inlet and pumped out through the outlet.

[0067] When the flexible pump tube 33 pumps liquid, the flow sensor 1 acquires a flow measurement value every 10ms and promptly transmits the flow measurement value to the control system. After the driver drives the pump head 32 to rotate 360°, the control system calculates the average value among the received multiple flow measurements, which is the detected flow value L1.

[0068] In one embodiment, obtaining the current flow rate and direction at the outlet of the pump body assembly 3 includes:

[0069] The current flow rate and direction are obtained through a non-contact flow sensor;

[0070] The pump body assembly 3 has a flexible pump pipe 33, which has an inlet and an outlet, and the flow sensor 1 is installed on the outlet.

[0071] Specifically, the flow sensor 1 is an ultrasonic flow sensor, which is installed at the outlet of the flexible pump tube 33. The ultrasonic flow sensor utilizes emitted ultrasonic waves to detect the liquid flow rate without requiring contact with the liquid inside the flexible pump tube 33. The flow sensor 1 does not physically affect the liquid flowing inside the flexible pump tube 33, nor does it contaminate the liquid within the flexible pump tube 33.

[0072] In one embodiment, the peristaltic pump backflow prevention control method of this application further includes:

[0073] Obtain the liquid pressure value at the outlet of pump body assembly 3;

[0074] When the liquid pressure reaches the set pressure value, the speed of pump body assembly 3 is maintained or reduced.

[0075] Specifically, when the speed of the pump assembly 3 is increased, the outlet pressure of the pump assembly 3 will increase. The pressure sensor 2 detects the pressure value of the liquid at the outlet of the pump assembly 3 in real time and compares the detected pressure value P1 with the set pressure value P2. When the detected pressure value P1 is equal to the set pressure value P2, the speed of the pump assembly 3 can be maintained or reduced to ensure that the pump assembly 3 is used within a safe load range.

[0076] More specifically, the set pressure value P2 is less than or equal to the rated pressure of the pump body assembly 3.

[0077] That is, when adjusting the speed of pump assembly 3, the working pressure of pump assembly 3 must be taken into account. If the outlet pressure of pump assembly 3 is greater than the rated pressure of the current model of pump assembly 3, it proves that the driving capacity of pump assembly 3 has reached its maximum and the injection pressure cannot be increased further. At this time, it is necessary to replace pump assembly 3 with one that has a higher rated working pressure to ensure that the load range of pump assembly 3 during use is within a safe range.

[0078] In one embodiment, the peristaltic pump backflow prevention control method further includes:

[0079] The control system acquires the pressure value detected by the pressure sensor 2 and controls the pump assembly 3 based on the acquired pressure value.

[0080] Specifically, the control system is electrically connected to pressure sensor 2 and pump assembly 3. After detecting the pressure of the liquid at the outlet of pump assembly 3, pressure sensor 2 can transmit the detected pressure value P1 to the control system. The control system can compare the detected pressure value P1 with the set pressure value P2, and when the detected pressure value P1 equals the set pressure value P2, it can maintain or reduce the rotational speed of pump assembly 3 to ensure the effective use of pump assembly 3.

[0081] In one embodiment, obtaining the liquid pressure value at the outlet of the pump body assembly 3 includes:

[0082] The measured pressure value is obtained at a second preset time interval;

[0083] The average of multiple measured pressure values ​​is calculated over the time interval during which the pump head 32 of the pump body assembly 3 rotates one revolution to obtain the liquid pressure value. The liquid pressure value is the pressure value P1 detected above.

[0084] Specifically, when the pump body assembly 3 is running, the control system can send a signal to the driver, causing the driver to drive the pump head 32 and roller 34 to rotate, thereby alternately squeezing and releasing the flexible pump tube 33, so that the liquid can be pumped into the flexible pump tube 33 through the inlet and pumped out through the outlet.

[0085] Pressure sensor 2 acquires a pressure measurement value every 10ms when the liquid is pumped by the flexible pump tube 33, and promptly transmits the pressure measurement value to the control system. After the driver drives the pump head 32 to rotate 360°, the control system calculates the average value among the multiple received pressure measurements, and this average value is the detected pressure value P1.

[0086] In one embodiment, obtaining the liquid pressure value at the outlet of the pump body assembly 3 includes:

[0087] Liquid pressure values ​​are obtained using a non-contact pressure sensor;

[0088] The pump body assembly 3 has a flexible pump tube 33, which has an inlet and an outlet, and the pressure sensor 2 is installed on the outlet.

[0089] Specifically, pressure sensor 2 is a strain gauge pressure sensor and is installed at the outlet of the flexible pump tube 33. The strain gauge pressure sensor can sense the liquid pressure within the flexible pump tube 33 through a structure such as a strain diaphragm or a movable plunger, allowing pressure sensor 2 to detect the liquid flow rate without contacting the liquid within the flexible pump tube 33. Pressure sensor 2 does not physically affect the liquid flowing within the flexible pump tube 33, nor does it contaminate the liquid within the flexible pump tube 33.

[0090] In one embodiment, the peristaltic pump backflow prevention control method of this application further includes:

[0091] Obtain the measured rate value of pump body assembly 3;

[0092] When the measured rate value reaches the set rate value, the rotational speed of the pump body assembly 3 is maintained or reduced. The set rate value is less than or equal to the rated rate of the pump body assembly 3.

[0093] In other words, when adjusting the speed of pump assembly 3, the rated speed of pump assembly 3 must be taken into account. If the measured speed of pump assembly 3 reaches the rated speed of the current model of pump assembly 3, it proves that the driving capacity of pump assembly 3 has reached its maximum and the speed cannot be increased further. At this time, it is necessary to replace pump assembly 3 with one that has a higher rated speed to ensure that the load range of pump assembly 3 during use is within a safe range.

[0094] In summary, when the peristaltic pump anti-backflow control method of this application is implemented for the pump body assembly 3 in operation, the pressure sensor 2 first detects the pressure value of the liquid at the outlet of the pump body assembly 3 in real time, and compares the detected pressure value P1 with the set pressure value P2 to determine whether the speed of the pump body assembly 3 can be increased. After determining that the detected pressure value P1 is less than the set pressure value P2, the flow sensor 1 detects the liquid flow rate at the outlet of the pump body assembly 3 in real time, and compares the detected flow rate value L1 with the set flow rate value L2 to determine whether liquid backflow has occurred. After determining that the detected flow rate value L1 is less than the set flow rate value L2 and liquid backflow has occurred, the control system determines whether the real-time speed of the pump body assembly 3 is less than the rated speed. After determining that the real-time speed of the pump body assembly 3 is less than the rated speed, the control system increases the speed of the pump body assembly 3 to increase the amount of liquid delivered by the pump body assembly 3 to the outlet, so that the increased amount of liquid cancels out the amount of backflowing liquid.

[0095] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0096] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for preventing backflow in a peristaltic pump, characterized in that, Includes the following steps: Obtain the current flow rate and direction at the outlet of the pump assembly; The pump assembly is controlled based on the current flow rate and direction, as well as the expected flow rate of the pump assembly in the current operating state. The step of controlling the pump assembly based on the current flow rate and flow direction, and the expected flow rate of the pump assembly in the current operating state, includes: When the pump assembly is in a stopped state, if the current flow rate is greater than 0 and the fluid flow direction is from the outlet to the inlet, the pump assembly is controlled to deliver fluid to the outlet, and the flow rate of the delivered fluid is equal to the current flow rate. When the pump assembly is in operation, the rotational speed of the pump assembly is controlled according to the current flow rate and the set flow rate of the pump assembly in the current operating state, so as to adjust the current flow rate to be consistent with the set flow rate.

2. The peristaltic pump backflow prevention control method according to claim 1, characterized in that, When the pump assembly is in operation, controlling the rotational speed of the pump assembly based on the current flow rate and the set flow rate of the pump assembly in the current operating state, so as to adjust the current flow rate to be consistent with the set flow rate, includes: If the current flow rate is less than the set flow rate, the pump assembly is controlled to increase its rotational speed until the current flow rate matches the set flow rate. If the current flow rate is greater than the set flow rate, the pump assembly is controlled to reduce its rotational speed until the current flow rate matches the set flow rate.

3. The peristaltic pump backflow prevention control method according to claim 1, characterized in that, The acquisition of the current flow rate and direction at the outlet of the pump assembly includes: The measured flow rate value is obtained at a first preset time interval; The average of multiple measured flow rates within the time period of one revolution of the pump head of the pump body assembly is calculated to obtain the current flow rate value.

4. The peristaltic pump backflow prevention control method according to claim 1, characterized in that, The acquisition of the current flow rate and direction at the outlet of the pump assembly includes: The current flow rate and direction are obtained using a non-contact flow sensor. The pump body assembly has a flexible pump tube, which has an inlet and an outlet, and the non-contact flow sensor is mounted on the outlet.

5. The peristaltic pump backflow prevention control method according to any one of claims 1 to 4, characterized in that, The peristaltic pump backflow prevention control method further includes: Obtain the liquid pressure value at the outlet of the pump body assembly; When the liquid pressure reaches the set pressure value, the rotational speed of the pump assembly is maintained or reduced.

6. The peristaltic pump backflow prevention control method according to claim 5, characterized in that, The set pressure value is less than or equal to the rated pressure of the pump body assembly.

7. The peristaltic pump backflow prevention control method according to claim 5, characterized in that, The step of obtaining the liquid pressure value at the outlet of the pump assembly includes: The measured pressure value is obtained at a second preset time interval; The average of multiple measured pressure values ​​is calculated over a time period during which the pump head of the pump body assembly rotates one revolution to obtain the liquid pressure value.

8. The peristaltic pump backflow prevention control method according to claim 5, characterized in that, The step of obtaining the liquid pressure value at the outlet of the pump assembly includes: The liquid pressure value is obtained using a non-contact pressure sensor; The pump body assembly has a flexible pump tube, which has an inlet and an outlet, and the non-contact pressure sensor is mounted on the outlet.

9. The peristaltic pump backflow prevention control method according to claim 5, characterized in that, The peristaltic pump backflow prevention control method further includes: Obtain the measured rate value of the pump body assembly; When the measured rate value reaches the set rate value, the rotational speed of the pump assembly is maintained or reduced.

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