Installation method for single-end mechanical seal of single-suction centrifugal pump

Abstract

The present invention belongs to the technical field of single-suction centrifugal pump mechanical seals, and specifically discloses an installation method for a single-end mechanical seal of a single-suction centrifugal pump, which includes determining the installation position of the mechanical seal seat on the shaft sleeve through the following steps: determining the total compression amount of the mechanical seal; determining the working compression amount of the mechanical seal based on the determined total compression amount of the mechanical seal; taking the shaft sleeve and the impeller sealing surface as the measurement reference surface, and determining the distance from the static ring surface of the mechanical seal to the measurement reference surface; determining the installation position of the mechanical seal seat on the shaft sleeve based on the determined working compression amount of the mechanical seal and the determined distance from the static ring surface of the mechanical seal to the measurement reference surface. The installation method provided by the present invention selects the shaft sleeve and the impeller sealing surface as the reference surface for measuring and adjusting dimensions, reduces the reference scribing error, measurement error, and the number of pump cover installations, improves the installation accuracy of the single-end mechanical seal of the single-suction centrifugal pump, and has the characteristics of simple, reliable, and high-efficiency installation calculation.

Description

Technical Field

[0001] The present invention belongs to the technical field of single-suction centrifugal pump mechanical seals, and particularly relates to an installation method for a single-end mechanical seal of a single-suction centrifugal pump. Background Art

[0002] The sealing method of horizontal single-suction centrifugal pumps generally adopts single-end mechanical seals, which are characterized by simple structure, low manufacturing cost, and convenient installation and disassembly. However, when installing single-end mechanical seals using the current installation method, there are problems such as complex mechanical seal calculation and installation, high labor intensity for replacement, long replacement operation time, and inability to guarantee assembly quality (for example, serious wear of the dynamic and static ring friction pairs or insufficient or excessive compression amount (installation compression amount) between the dynamic and static ring friction pairs) resulting in poor mechanical seal tightness and short service life.

[0003] In view of this, the present invention is specifically proposed. Summary of the Invention

[0004] To solve at least one of the above problems, the present invention provides an installation method for a single-end mechanical seal of a single-suction centrifugal pump.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] According to the present invention, there is provided an installation method for a single-end mechanical seal of a single-suction centrifugal pump, which includes determining the installation position of the mechanical seal seat on the shaft sleeve through the following steps:

[0007] Determine the total compression amount of the mechanical seal;

[0008] Based on the determined total compression amount of the mechanical seal, determine the working compression amount of the mechanical seal;

[0009] Take the shaft sleeve and the impeller sealing surface as the measurement reference surface, and determine the distance from the static ring surface of the mechanical seal to the measurement reference surface;

[0010] Based on the determined working compression amount of the mechanical seal and the determined distance from the static ring surface of the mechanical seal to the measurement reference surface, determine the installation position of the mechanical seal seat on the shaft sleeve.

[0011] According to an embodiment of the present invention, the total compression amount of the mechanical seal is determined based on the total length of the mechanical seal in the completely relaxed state of the mechanical seal spring and the total length of the mechanical seal in the completely compressed state of the mechanical seal spring.

[0012] According to an embodiment of the present invention, the working compression amount of the mechanical seal is determined based on the determined total compression amount of the mechanical seal, the flow rate, and the pressure of the single-suction centrifugal pump.

[0013] According to an embodiment of the present invention, the working compression amount of the mechanical seal is determined empirically based on the determined total compression amount of the mechanical seal, the flow rate of the single-suction centrifugal pump, and the pressure.

[0014] According to an embodiment of the present invention, the distance from the static ring surface of the mechanical seal to the measurement reference surface is determined as follows: Install the static ring and the O-ring in the static ring seat, install the static ring seat on the pump cover and fix it; then install the pump cover on the bearing housing and fix it; install the shaft sleeve on the pump shaft, and measure the distance from the static ring surface of the mechanical seal to the measurement reference surface.

[0015] According to an embodiment of the present invention, the installation position of the mechanical seal seat on the shaft sleeve is determined based on the determined working compression amount of the mechanical seal, the determined distance from the static ring surface of the mechanical seal to the measurement reference surface, and the total length of the mechanical seal in the completely relaxed state of the mechanical seal spring.

[0016] According to an embodiment of the present invention, the single-end mechanical seal installation method for the single-suction centrifugal pump further includes: after determining the installation position of the mechanical seal seat on the shaft sleeve, according to the determined installation position of the mechanical seal seat on the shaft sleeve, install the mechanical seal seat, the mechanical seal spring, the O-ring, and the dynamic ring on the shaft sleeve and fix the mechanical seal seat.

[0017] According to an embodiment of the present invention, the single-end mechanical seal installation method for the single-suction centrifugal pump further includes: Install the shaft sleeve with the installed mechanical seal seat, mechanical seal spring, O-ring, and dynamic ring on the pump shaft, install the impeller on the pump shaft and lock it with the impeller cap, then install the whole back on the pump body, install the motor to align the coaxiality and the coupling, and perform maintenance, clean the site, and test the machine for operation.

[0018] According to an embodiment of the present invention, the single-end mechanical seal installation method for the single-suction centrifugal pump further includes: Before installing the mechanical seal, disassemble the mechanical seal to be installed for pre-installation inspection.

[0019] According to an embodiment of the present invention, the pre-installation inspection of the mechanical seal includes: checking whether there is damage to the appearance of the static and dynamic ring friction pairs, the sealing performance of the sealing surface, and whether there is damage to the static and dynamic ring O-rings.

[0020] Adopting the above technical solutions, the present invention has the following beneficial effects:

[0021] The single-end mechanical seal installation method for the single-suction centrifugal pump provided by the present invention selects the sealing surface of the shaft sleeve and the impeller as the reference surface for measuring and adjusting dimensions, reduces the reference scribing error, measurement error, and the number of pump cover installations, improves the installation accuracy of the single-end mechanical seal of the single-suction centrifugal pump, and has the characteristics of simple, reliable, and high-efficiency installation calculation. Description of the Drawings

[0022] Figure 1Schematic flowchart of the installation method of the single - end mechanical seal of a single - suction centrifugal pump provided by an embodiment of the present invention;

[0023] Figure 2 Schematic diagram of the installation position of the mechanical seal;

[0024] Figure 3 Schematic diagram of the free state of the mechanical seal;

[0025] Figure 4 Schematic diagram of the fully compressed state of the mechanical seal;

[0026] Figure 5 Schematic diagram for measuring the distance from the static ring surface to the measurement reference surface;

[0027] Figure 6 Schematic diagram of the calculation principle of the installation position of the mechanical seal seat on the shaft sleeve;

[0028] Figure 7 Schematic flowchart of the installation method of the single - end mechanical seal of a single - suction centrifugal pump provided by another embodiment of the present invention. Detailed implementation manners

[0029] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] As needed, specific embodiments of the present invention are disclosed in the specification of the present invention; however, it should be understood that the embodiments disclosed herein are only examples of the present invention that can be implemented in multiple, alternative forms. In the following description, multiple operating parameters and components are described in multiple conceived embodiments. These specific parameters and components are only examples in this specification and do not mean to limit.

[0031] The existing installation method of the single-end mechanical seal for a single-suction centrifugal pump includes: after installing the stationary ring of the mechanical seal and the O-ring on the stationary ring seat, measuring and calculating the size between the friction surface of the stationary ring and the installation plane of the stationary ring seat (the size between the friction surface of the stationary ring and the installation plane of the stationary ring seat = the size between the friction surface of the stationary ring and the stop of the stationary ring seat - the size from the stop of the stationary ring seat to the installation plane of the stationary ring seat); installing the pump cover on the bearing box or bracket; installing the seal seat, seal spring, O-ring and rotating ring of the mechanical seal on the shaft sleeve; installing the shaft sleeve with the installed seal seat, seal spring, O-ring and rotating ring on the pump shaft; then using a saw blade or scriber to scribe a line on the rotating ring of the mechanical seal installed on the shaft sleeve through the end face of the stationary ring seat installed on the pump cover (i.e., taking the installation plane of the stationary ring seat installed on the pump cover as the reference and scribing a line on the rotating ring); removing the shaft sleeve and the pump cover, and measuring the size from the friction surface of the rotating ring on the shaft sleeve to the scribed line; calculating the installation position of the mechanical seal according to the working compression amount of the mechanical seal, the measured size between the friction surface of the stationary ring and the installation plane of the stationary ring seat, and the size from the friction surface of the rotating ring to the scribed line (the installation position of the mechanical seal = the size from the friction surface of the rotating ring to the scribed line - the size between the friction surface of the stationary ring and the installation plane of the stationary ring seat + the working compression amount of the mechanical seal).

[0032] Due to the long dimension chain and large reference selection error when calculating the installation position of the mechanical seal in the existing installation method of the single-end mechanical seal for a single-suction centrifugal pump, the friction pairs of the stationary and rotating rings of the mechanical seal after replacement are severely worn, or the compression amount (installation compression amount) between the friction pairs of the stationary and rotating rings is insufficient or excessive, resulting in poor sealing performance of the mechanical seal, short service life, high maintenance frequency, and high safety and environmental protection risks. The reference selection error includes scribing error, measurement error, and calculation error. Specifically, the existing method uses scribing to set the measurement reference, and the position error of the reference line increases the measurement error; there are many measured dimensions, which makes the measurement error and calculation error superimpose more, resulting in a large deviation in the installation and calculation of the compression amount. In addition, the pump cover in the existing method needs to be installed twice, and it takes 3 people 8 hours to replace the mechanical seal, with a large replacement labor intensity and a long operation time.

[0033] In view of the above problems, the present invention provides an installation method for the single-end mechanical seal of a single-suction centrifugal pump, which selects the sealing surface between the shaft sleeve and the impeller as the reference surface for measuring and adjusting dimensions, reduces the reference scribing error, measurement error, and the number of pump cover installations, and improves the installation accuracy of the single-end mechanical seal of the single-suction centrifugal pump.

[0034] Figure 1 The flowchart showing the installation method of the single-end mechanical seal of a single-suction centrifugal pump according to an embodiment of the present invention is as follows. As Figure 1As shown, the installation method 10 of the single-end mechanical seal of the single-suction centrifugal pump includes the following steps: S11: Determine the total compression amount of the mechanical seal; S12: Determine the working compression amount of the mechanical seal based on the determined total compression amount of the mechanical seal; S13: Take the shaft sleeve and the impeller sealing surface as the measurement reference surface, and determine the distance from the static ring surface of the mechanical seal to the measurement reference surface; S14: Based on the determined working compression amount of the mechanical seal and the determined distance from the static ring surface of the mechanical seal to the measurement reference surface, determine the installation position of the mechanical seal seat on the shaft sleeve.

[0035] In step S11, the total compression amount of the mechanical seal refers to the maximum possible compression amount of the mechanical seal, which can be determined according to the total length of the mechanical seal in the completely relaxed state of the mechanical seal spring and the total length of the mechanical seal in the completely compressed state of the mechanical seal spring. Specifically, the total compression amount of the mechanical seal = the total length of the mechanical seal in the completely relaxed state of the mechanical seal spring - the total length of the mechanical seal in the completely compressed state of the mechanical seal spring. Here, the total length of the mechanical seal can either include the height of the static ring and the static ring seat or not include the height of the static ring and the static ring seat. For example, Figure 3 shows a schematic diagram of the free state of the mechanical seal, Figure 3 where the dimension A1 in represents the total length of the mechanical seal in the completely relaxed state of the mechanical seal spring, Figure 4 shows a schematic diagram of the completely compressed state of the mechanical seal, attached Figure 4 where the dimension A2 in represents the total length of the mechanical seal in the completely compressed state of the mechanical seal spring. As shown in the figure, the total length of the mechanical seal shown here does not include the height of the static ring and the static ring seat. Before installation, disassemble the mechanical seal to be installed and measure the total compression amount of the mechanical seal to ensure more accurate measurement and calculation of the installation compression amount of the mechanical seal.

[0036] In step S12, the working compression amount of the mechanical seal is determined based on the determined total compression amount of the mechanical seal, the flow rate, and the pressure of the single-suction centrifugal pump. In particular, it is determined based on the determined total compression amount of the mechanical seal, the flow rate, and the pressure of the single-suction centrifugal pump by experience.

[0037] In step S13, taking the shaft sleeve and the impeller sealing surface as the measurement reference surface can more accurately measure the distance from the static ring surface of the mechanical seal to the shaft sleeve and the impeller sealing surface, and can more accurately determine the position of the dynamic ring seat of the mechanical seal on the shaft sleeve. The position of the dynamic ring seat of the mechanical seal on the shaft sleeve is the key point of the mechanical seal installation, which will affect the sealing performance and service life of the mechanical seal. The distance from the static ring surface of the mechanical seal to the measurement reference surface is determined as follows: Install the static ring and the O-ring in the static ring seat, install the static ring seat on the pump cover and fix it; then install the pump cover on the bearing box and fix it; install the shaft sleeve on the pump shaft and measure the distance from the static ring surface of the mechanical seal to the measurement reference surface. Specifically, the distance from the static ring surface of the mechanical seal to the measurement reference surface can be measured with a depth gauge or a vernier caliper with a depth scale. Figure 5Schematic diagram for measuring the distance from the static seal ring surface to the measurement reference surface Figure 5 The dimension A3 in Figure 5 represents the distance from the static seal ring surface of the mechanical seal to the measurement reference surface.

[0038] In step S14, the installation position of the mechanical seal housing on the shaft sleeve is determined based on the determined working compression amount of the mechanical seal, the determined distance from the static seal ring surface of the mechanical seal to the measurement reference surface, and the total length of the mechanical seal in the fully relaxed state of the mechanical seal spring. Figure 2 Schematic diagram of the installation position of the mechanical seal Figure 2 The dimension A in Figure 2 represents the installation position of the mechanical seal housing on the shaft sleeve. Specifically, the installation position of the mechanical seal housing on the shaft sleeve (as shown by A in Figure 2 Figure 2 ) = the distance from the static seal ring surface of the mechanical seal to the measurement reference surface (as shown by A3 in Figure 5 Figure 5 ) - the total length of the mechanical seal in the fully relaxed state of the mechanical seal spring (as shown by A1 in Figure 3 Figure 3 ) + the working compression amount of the mechanical seal. Figure 6 Schematic diagram of the calculation principle of the installation position of the mechanical seal housing on the shaft sleeve, from which the above relationship can be clearly shown.

[0039] Figure 7 The flowchart of the installation method of the single - suction centrifugal pump single - end mechanical seal according to another embodiment of the present invention is shown. As Figure 7 shown, the installation method 20 of the single - suction centrifugal pump single - end mechanical seal includes the following steps: S21: Conduct pre - installation inspection of the mechanical seal; S22: Determine the total compression amount of the mechanical seal and determine the working compression amount of the mechanical seal based on the determined total compression amount of the mechanical seal; S23: Install the static seal ring and the O - ring in the static seal ring seat, install the static seal ring seat on the pump cover and fix it, and then install the pump cover on the bearing box and fix it; S24: Install the shaft sleeve on the pump shaft, use the shaft sleeve and the impeller sealing surface as the measurement reference surface, and measure the distance from the static seal ring surface of the mechanical seal to the measurement reference surface; S25: Determine the installation position of the mechanical seal housing on the shaft sleeve based on the determined working compression amount of the mechanical seal and the determined distance from the static seal ring surface of the mechanical seal to the measurement reference surface; S26: Remove the shaft sleeve, and install the mechanical seal housing, the mechanical seal spring, the O - ring, and the dynamic seal ring on the shaft sleeve according to the determined installation position of the mechanical seal housing on the shaft sleeve and fix the mechanical seal housing; S27: Install the shaft sleeve with the mechanical seal housing, the mechanical seal spring, the O - ring, and the dynamic seal ring installed on the pump shaft, install the impeller on the pump shaft and lock it with the impeller cap, then install the whole assembly back onto the pump body, install the motor, align the coaxiality and the coupling, and clean up the site and test - run the machine.

[0040] In step S21, the pre - installation inspection of the mechanical seal includes: disassembling the mechanical seal to be installed, checking whether there is damage to the appearance of the static and dynamic ring friction pairs, the sealing performance of the sealing surface, and whether there is damage to the static and dynamic ring O - rings. Conducting pre - installation inspection of the mechanical seal can better ensure the success rate of the mechanical seal installation.

[0041] Step S22 is the same as the above-described steps S11 and S12, steps S23 and S24 are the same as the above-described step S13, and step S25 is the same as the above-described step S14. Referring to the above description, it will not be elaborated here.

[0042] Compared with the existing installation method of the single-end mechanical seal of the single-suction centrifugal pump described above, the installation method of the single-end mechanical seal of the single-suction centrifugal pump provided by the present invention has the following advantages: The shaft sleeve and the impeller sealing surface are used as the reference surfaces for measuring and adjusting dimensions. The reference surfaces are fixed, reducing measurement errors and making the determination of the mechanical seal position more accurate; Now there are fewer measured dimensions, resulting in less superposition of measurement errors and calculation errors, making the installation and calculation of the compression amount of the mechanical seal accurate; The pump cover only needs to be installed once. It takes 2 people 6 hours to replace the mechanical seal, shortening the maintenance time, improving the maintenance efficiency, and reducing the labor intensity of maintenance personnel; The mechanical seal of the installation method of the present invention has a long service life and fewer maintenance times, reducing the cost of spare parts and materials, saving the equipment maintenance cost, reducing the safety and environmental protection risks, and increasing the equipment operating rate.

[0043] It should be particularly noted that each component or step in the above-mentioned various embodiments can be mutually crossed, replaced, added, or deleted. Therefore, the combinations formed by these reasonable permutations and combinations should also fall within the protection scope of the present invention, and the protection scope of the present invention should not be limited to the above-mentioned embodiments.

[0044] The above are the exemplary embodiments disclosed by the present invention. The order of disclosure of the above embodiments of the present invention is only for description and does not represent the superiority or inferiority of the embodiments. However, it should be noted that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of disclosure of the embodiments of the present invention (including the claims) is limited to these examples. Without departing from the scope defined by the claims, various changes and modifications can be made. The functions, steps, and / or actions of the method claims according to the disclosed embodiments here do not need to be performed in any specific order. In addition, although the elements disclosed in the embodiments of the present invention can be described or claimed in individual form, they can also be understood as plural unless explicitly limited to the singular.

[0045] Those of ordinary skill in the art should understand that: The discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of disclosure of the embodiments of the present invention (including the claims) is limited to these examples; Under the idea of the embodiments of the present invention, the technical features between the above embodiments or different embodiments can also be combined, and there are many other variations in different aspects of the embodiments of the present invention as described above, which are not provided in detail for the sake of brevity. Therefore, any omission, modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.

Claims

1. A method for installing a single-end mechanical seal of a single-suction centrifugal pump, characterized in that, Including determining the installation position of the mechanical seal seat on the shaft sleeve through the following steps: Determining the total compression amount of the mechanical seal; Based on the determined total compression amount of the mechanical seal, the flow rate and pressure of the single-suction centrifugal pump, determining the working compression amount of the mechanical seal; Taking the shaft sleeve and the impeller sealing surface as the measurement reference surface, determining the distance from the static ring surface of the mechanical seal to the measurement reference surface through the following method: Install the static ring and the O-ring in the static ring seat, install the static ring seat on the pump cover and fix it, then install the pump cover on the bearing box and fix it, install the shaft sleeve on the pump shaft, and measure the distance from the static ring surface of the mechanical seal to the measurement reference surface; Based on the determined working compression amount of the mechanical seal, the determined distance from the static ring surface of the mechanical seal to the measurement reference surface, and the total length of the mechanical seal in the completely relaxed state of the mechanical seal spring, determining the installation position of the mechanical seal seat on the shaft sleeve.

2. The installation method of the single-end mechanical seal of the single-suction centrifugal pump according to claim 1, characterized in that, The total compression amount of the mechanical seal is determined according to the total length of the mechanical seal in the completely relaxed state of the mechanical seal spring and the total length of the mechanical seal in the completely compressed state.

3. The installation method of the single-end mechanical seal of the single-suction centrifugal pump according to claim 1, characterized in that, The working compression amount of the mechanical seal is determined empirically based on the determined total compression amount of the mechanical seal, the flow rate and pressure of the single-suction centrifugal pump.

4. The installation method of the single-ended mechanical seal of the single-suction centrifugal pump according to claim 1, characterized in that, The installation method of the single-suction centrifugal pump single-end mechanical seal further includes: After determining the installation position of the mechanical seal seat on the shaft sleeve, according to the determined installation position of the mechanical seal seat on the shaft sleeve, installing the mechanical seal seat, the mechanical seal spring, the O-ring and the dynamic ring on the shaft sleeve and fixing the mechanical seal seat.

5. The installation method of the single-end mechanical seal of the single-suction centrifugal pump according to claim 4, characterized in that, The installation method of the single-suction centrifugal pump single-end mechanical seal further includes: Installing the shaft sleeve with the mechanical seal seat, the mechanical seal spring, the O-ring and the dynamic ring installed on the pump shaft, installing the impeller on the pump shaft and locking it with the impeller cap, then reinstalling the whole onto the pump body, installing the motor to align the coaxiality and the coupling, and overhauling and cleaning the site for trial operation.

6. The installation method of the single-ended mechanical seal of the single-suction centrifugal pump according to claim 1, characterized in that, The installation method of the single-suction centrifugal pump single-end mechanical seal further includes: Before installing the mechanical seal, disassembling the mechanical seal to be installed for pre-installation inspection.

7. The installation method of the single-end mechanical seal of the single-suction centrifugal pump according to claim 6, characterized in that, The pre-installation inspection of the mechanical seal includes: Checking whether there are damages on the appearance of the static and dynamic ring friction pairs, the sealing performance of the sealing surface, and whether there are damages on the static and dynamic ring O-rings.

Images