A packing seal front pressure chamber pressure regulating device and self-balancing multi-stage centrifugal pump

Abstract

The application relates to a pressure adjusting device for a pre-filling sealing pressure chamber and a self-balancing multi-stage centrifugal pump, which comprises a pressure relief pipeline, an electromagnetic throttle valve and a pressure sensor, one end of the pressure relief pipeline is connected with a pre-filling sealing pressure chamber of the self-balancing multi-stage centrifugal pump, the other end of the pressure relief pipeline is connected with a pump suction inlet of the self-balancing multi-stage centrifugal pump, the electromagnetic throttle valve is arranged on the pressure relief pipeline, the electromagnetic throttle valve is used for adjusting the flow size in the pressure relief pipeline, and the pressure sensor is used for monitoring the pressure in the pre-filling sealing pressure chamber or in the pressure relief pipeline. Compared with the prior art, the application can keep the pressure of the pre-filling sealing pressure chamber stable under various working conditions, can avoid problems such as dry grinding and smoking of the filling, and can ensure normal work.

Description

Technical Field

[0001] This invention relates to the field of centrifugal pump technology, and in particular to a pressure regulating device for the pressure chamber before the packing seal and a self-balancing multistage centrifugal pump. Background Technology

[0002] The self-balancing multistage centrifugal pump is characterized by its structure, which completely eliminates the balancing system used in traditional multistage pumps to balance axial force. Instead, it relies on the symmetrical arrangement of impellers to automatically balance axial force. It has fewer vulnerable parts and runs smoothly, and is widely used in mining, irrigation and other applications.

[0003] Because mining and irrigation water supply and drainage typically contain a certain amount of solid particles, self-balancing multistage centrifugal pumps often employ packing seals. However, the effectiveness of these seals is influenced by factors such as pump inlet pressure, medium characteristics, pump flow components, and packing material. These factors ultimately affect the sealing performance by causing changes in the pressure chamber before the packing seal. Furthermore, changes in the pressure chamber before the packing seal can lead to problems such as dry grinding and smoke from the packing, and severe leakage during the operation of the multistage centrifugal pump, seriously impacting normal operation. Therefore, controlling the pressure chamber before the packing seal in a self-balancing multistage centrifugal pump is essential. This is of great significance for pump design, production, and use, and is one of the important means to improve pump technology. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects of the prior art by providing a pressure regulating device for the pressure chamber before the packing seal and a self-balancing multi-stage centrifugal pump.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A pressure regulating device for the pre-pressure chamber of a packing seal includes a pressure relief pipe, an electromagnetic throttle valve, and a pressure sensor. One end of the pressure relief pipe is connected to the pre-pressure chamber of a self-balancing multistage centrifugal pump, and the other end is connected to the pump inlet of the self-balancing multistage centrifugal pump. The electromagnetic throttle valve is installed on the pressure relief pipe and is used to regulate the flow rate in the pressure relief pipe. The pressure sensor is used to monitor the pressure in the pre-pressure chamber or the pressure relief pipe.

[0007] Furthermore, it also includes a controller, wherein both the electromagnetic throttle valve and the pressure sensor are connected to the controller, and the controller is configured to perform the following steps:

[0008] S1. Obtain the current pressure data from the pressure sensor as the first pressure data;

[0009] S2. Compare the first pressure data with the set first threshold range:

[0010] If the first pressure data is within the first threshold range, then step S1 is executed again;

[0011] If the first pressure data is greater than the maximum value of the first threshold interval, then proceed to step S3;

[0012] If the first pressure data is less than the minimum value of the first threshold interval, then proceed to step S4;

[0013] S3. Reduce the opening value of the electromagnetic throttle valve according to the set value, and at the same time collect the data of the pressure sensor to obtain the second pressure data until the second pressure data is less than the second threshold. Maintain the current opening value of the electromagnetic throttle valve and repeat step S1.

[0014] S4. Increase the opening value of the electromagnetic throttle valve according to the set value, and at the same time collect the data of the pressure sensor to obtain the second pressure data until the second pressure data is greater than the third threshold. Maintain the current opening value of the electromagnetic throttle valve and repeat step S1.

[0015] The third threshold is less than or equal to the second threshold, and both the third threshold and the second threshold are within the first threshold range.

[0016] Furthermore, the pressure relief pipe includes a first pipe and a second pipe. One end of the first pipe is connected to the front pressure chamber. The pressure sensor is fixed at the other end of the first pipe. The probe of the pressure sensor is located inside the pressure relief pipe or extends through the first pipe into the front pressure chamber. One end of the second pipe is connected to the middle of the first pipe.

[0017] Furthermore, the pressure relief pipe is fixed to the casing of the self-balancing multistage centrifugal pump by a support frame.

[0018] A self-balancing multistage centrifugal pump is provided with the aforementioned pressure regulating device for the pressure chamber before the packing seal.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] This invention utilizes an electromagnetic throttle valve and a pressure sensor on the pressure relief pipe connecting the pressure chamber before the packing seal and the pump inlet to actively regulate the pressure in the pressure chamber before the packing seal. This ensures that the pressure in the pressure chamber before the packing seal remains stable under various operating conditions, preventing problems such as dry grinding and smoke from the packing or severe leakage, thus ensuring normal operation. At the same time, when the packing operates stably under the optimal working pressure, it achieves the best cooling, sealing, and lubrication effects, slowing down the aging rate of the packing and extending the service life of the pump. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a self-balancing multistage centrifugal pump.

[0022] Figure 2 This is a schematic diagram of the pressure regulating device.

[0023] Figure 3 This is a flowchart illustrating the execution of a program within the controller.

[0024] Reference numerals: 1. Pressure relief pipe; 11. First pipe; 12. Second pipe; 2. Electromagnetic throttle valve; 3. Pressure sensor; 4. Pump inlet; 5. Pressure chamber before packing seal; 6. Secondary inlet; 7. Throttling sleeve; 8. Shaft sleeve; 9. Packing seal; 10. Packing flushing port. Detailed Implementation

[0025] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0026] like Figure 1 and Figure 2 As shown, this embodiment provides a self-balancing multistage centrifugal pump, which includes a pressure regulating device for the pressure chamber before the packing seal. This pressure regulating device utilizes the principle of pressure balance at each interface of a communicating vessel to help the packing seal adapt to different operating conditions. It monitors and adjusts the pressure in the pressure chamber before the packing seal, thereby solving the problem of the packing seal failing to operate normally due to pressure changes in the pressure chamber, such as dry grinding and smoke from the packing, and severe leakage. The pressure regulating device specifically includes a pressure relief pipe 1, an electromagnetic throttle valve 2, a pressure sensor 3, and a controller. The pressure relief pipe 1 is fixed to the housing of the multistage centrifugal pump by a support frame. One end of the pressure relief pipe 1 connects to the pressure chamber 5 before the packing seal of the self-balancing multistage centrifugal pump, and the other end connects to the pump inlet 4 of the self-balancing multistage centrifugal pump. The pressure sensor 3 and the electromagnetic throttle valve 2 are installed in the pressure relief pipe 1. In this embodiment, the pressure relief pipe 1 includes a first pipe 11 and a second pipe 12. One end of the first pipe 11 is connected to the pressure chamber 5 before the packing seal. The pressure sensor 3 is a probe-type pressure sensor, installed at the upper end of the first pipe 11, with its probe extending through the first pipe 11 into the pressure chamber 5 before the packing seal to directly detect the pressure in the pressure chamber 5 before the packing seal. One end of the second pipe 12 is connected to the middle of the first pipe 11, and the other end is connected to the pump inlet 4. Both the electromagnetic throttle valve 2 and the pressure sensor 3 are connected to the controller. In other embodiments, the probe may also indirectly detect the pressure in the pressure chamber 5 before the packing seal only within the first pipe 11.

[0027] The working principle of this embodiment is as follows: The probe of pressure sensor 3 penetrates into the pressure chamber 5 before the packing seal to detect the pressure in the pressure chamber 5 in real time, and controls the opening of electromagnetic throttle valve 2 through an electrical signal. Once the working conditions change, causing the pressure in the pressure chamber to change and deviate from the optimal pressure range, pressure sensor 3 feeds back an electrical signal to electromagnetic throttle valve 2. Electromagnetic throttle valve 2 controls the opening and closing of its valve disc to adjust the flow path in the entire pressure relief pipeline 1, ultimately adjusting the pressure in the pressure chamber to return it to the optimal pressure range. Based on the above principle, as... Figure 3 As shown, the controller in this embodiment is specifically configured to perform the following steps:

[0028] Step S1: Obtain the current pressure data of pressure sensor 3 as the first pressure data;

[0029] Step S2: Compare the first pressure data with the set first threshold range:

[0030] If the first pressure data is within the first threshold range, then step S1 is executed again;

[0031] If the first pressure data is greater than the maximum value of the first threshold interval, then proceed to step S3;

[0032] If the first pressure data is less than the minimum value of the first threshold interval, then proceed to step S4;

[0033] Step S3: Reduce the opening value of the electromagnetic throttle valve 2 according to the set value, and at the same time collect the data of the pressure sensor 3 to obtain the second pressure data until the second pressure data is less than the second threshold. Maintain the current opening value of the electromagnetic throttle valve 2 and repeat step S1.

[0034] Step S4: Increase the opening value of the electromagnetic throttle valve 2 according to the set value, and at the same time collect the data of the pressure sensor 3 to obtain the second pressure data until the second pressure data is greater than the third threshold. Maintain the current opening value of the electromagnetic throttle valve 2 and repeat step S1.

[0035] In the above steps, the material of the packing is first selected based on the characteristics of the medium. The optimal pressure range of the pressure chamber is determined as the first threshold range based on the flushing pressure and the packing material. The third threshold is less than or equal to the second threshold, and both the third and second thresholds are within the first threshold range.

[0036] Parameter settings for electromagnetic throttle valve 2: The flow area of ​​pressure relief pipe 1 is calculated based on the difference between the midpoint of the first threshold range and the rated inlet pressure of the pump, and the rated opening of electromagnetic throttle valve 2 is set accordingly. At the same time, the maximum and minimum opening of electromagnetic throttle valve 2, as well as the pressure change rate corresponding to the opening of electromagnetic throttle valve 2, are determined according to the pressure limit value of the working conditions and the relevant values ​​are set.

[0037] The diameter setting of the pressure relief pipe 1: Generally, the pressure in the pressure chamber 5 before the packing seal is equal to the sum of the pump inlet pressure and the friction loss along the pressure relief pipe 1. The friction loss is related to the diameter and length of the pressure relief pipe, as well as the liquid flow velocity within it. Its value is the product of the friction ratio selected according to the pipe diameter and flow velocity, and the square of the pipe length and flow rate. Considering the characteristics of the flowing medium, such as viscosity, pump inlet ultimate pressure, and the flow velocity in the pressure relief pipe when the flow components require the optimal sealing clearance, the diameter of the pressure relief pipe 1 should be increased accordingly based on the limit value of the allowable operating conditions. At the same time, since the opening and closing of the electromagnetic throttle valve 2 can adjust the effective diameter of the pressure relief pipe, increasing the pipe diameter also improves the adjustable range of the pressure relief pipe, allowing for faster adjustment of the pressure chamber pressure, and ultimately timely adjustment of the pressure chamber 5 before the packing seal.

[0038] The effects and advantages that can be achieved by this embodiment are listed below:

[0039] 1. Wide range of applications. The packing seal can operate normally under various working conditions without problems such as dry grinding and smoke, or serious leakage. 2. Extended packing replacement cycle and pump service life. When the packing operates at the optimal working pressure, it achieves optimal cooling, sealing, and lubrication effects, slowing down the aging rate of the packing and thus extending the pump's service life. 3. Automatic control and timely adjustment. Automatic monitoring ensures timely adjustment if the operation deviates from the optimal range, making it safe, convenient, and reliable. 4. Simple structure and easy installation.

[0040] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A packing seal front pressure chamber pressure regulating device characterized by, The system includes a pressure relief pipe (1), an electromagnetic throttle valve (2), and a pressure sensor (3). One end of the pressure relief pipe (1) is connected to the pressure chamber (5) before the packing seal of a self-balancing multi-stage centrifugal pump, and the other end is connected to the pump inlet (4) of the self-balancing multi-stage centrifugal pump. The electromagnetic throttle valve (2) is installed on the pressure relief pipe (1) and is used to adjust the flow rate in the pressure relief pipe (1). The pressure sensor (3) is used to monitor the pressure in the pressure chamber (5) before the packing seal or in the pressure relief pipe (1). The device also includes a controller, which is connected to both the electromagnetic throttle valve (2) and the pressure sensor (3), and the controller is configured to perform the following steps: S1. Obtain the current pressure data of the pressure sensor (3) as the first pressure data; S2. Compare the first pressure data with the set first threshold range: If the first pressure data is within the first threshold range, then step S1 is executed again; If the first pressure data is greater than the maximum value of the first threshold interval, then proceed to step S3; If the first pressure data is less than the minimum value of the first threshold interval, then proceed to step S4; S3. Reduce the opening value of the electromagnetic throttle valve (2) according to the set value, and at the same time collect the data of the pressure sensor (3) to obtain the second pressure data until the second pressure data is less than the second threshold. Maintain the current opening value of the electromagnetic throttle valve (2) and repeat step S1. S4. Increase the opening value of the electromagnetic throttle valve (2) according to the set value, and at the same time collect the data of the pressure sensor (3) to obtain the second pressure data until the second pressure data is greater than the third threshold. Maintain the current opening value of the electromagnetic throttle valve (2) and repeat step S1. The third threshold is less than or equal to the second threshold, and both the third threshold and the second threshold are within the first threshold range; The pressure relief pipe (1) includes a first pipe (11) and a second pipe (12). One end of the first pipe (11) is connected to the pressure chamber (5) before the packing seal. The pressure sensor (3) is fixed at the other end of the first pipe (11). The probe of the pressure sensor (3) is located inside the pressure relief pipe (1) or extends through the first pipe (11) into the pressure chamber (5) before the packing seal. One end of the second pipe (12) is connected to the middle of the first pipe (11).

2. A precharge pressure regulating device for a packing seal according to claim 1, characterized in that The pressure relief pipe (1) is fixed to the casing of the self-balancing multistage centrifugal pump by a support frame.

3. A self-balancing multi-stage centrifugal pump, characterized by, The self-balancing multistage centrifugal pump is equipped with a pressure regulating device for the pressure chamber before the packing seal as described in any one of claims 1 to 2.

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