Method for adjusting the axial balance force of canned motor pump

Abstract

The present invention discloses a canned pump chamber structure and a method for adjusting the axial balance force of a canned pump, which relates to the technical field of canned pumps. The main purpose is to adjust the balance of the axial force of a canned pump rotor component so that the rotor component returns to a normal position. The main technical scheme of the present invention is: a canned pump chamber structure, which includes: a volute and a plurality of spoilers; the plurality of spoilers are evenly distributed in an annular manner on the inner side of the volute.

Description

Technical Field

[0001] The present invention relates to the technical field of canned pumps, and in particular to a canned pump chamber structure and a method for adjusting the axial balance force of a canned pump. Background Art

[0002] Shielded pumps are widely used in chemical production. The pump uses Si-C bearing kits as radial support. The balancing force of the rotor components along the axial direction relies on the liquid medium to form a unique flow channel inside the pump to achieve the "hydraulic balance" of the rotor components.

[0003] When the silicon powder particles in the material wear out the components in the pump flow channel (the wear of the parts size causes the gap to change), the "hydraulic balance" of the rotor components will be destroyed, and the shielded pump will operate abnormally or even suffer serious failures.

[0004] During maintenance and repair, cold welding and machining are used to restore the "flow channel" size of key parts such as the impeller front ring, back ring, wear-resistant disk, etc. in the hope of restoring the "hydraulic balance" of the entire pump.

[0005] During the practice, the inventor found that the prior art has at least the following problems:

[0006] In some cases (especially with large flow and high head), it is extremely difficult to restore the "hydraulic balance". The axial thrust of the rotor parts points to the inlet direction and cannot be eliminated by restoring the accuracy of the parts. The reason is that the dimensions of some parts that affect the "hydraulic balance" flow channel cannot be fully restored to accuracy, for example: ① The front end of the impeller and the mouth ring are thin-walled parts, and cold welding cannot fully restore the accuracy after wear; ② The grooves near the volute mouth ring and the wear-resistant plate cannot be fully restored to accuracy after wear by cold welding. Summary of the invention

[0007] In view of this, the present invention provides a canned pump chamber structure and a method for adjusting the axial balance force of the canned pump, the main purpose of which is to adjust the balance of the axial force of the rotor component of the canned pump to restore the rotor component to a normal position.

[0008] In order to achieve the above object, the present invention mainly provides the following technical solutions:

[0009] In one aspect, the present invention provides a canned pump chamber structure, which includes: a volute and a plurality of spoilers;

[0010] The plurality of spoilers are evenly distributed in an annular shape on the inner side surface of the volute.

[0011] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0012] Optionally, the number of the spoilers is four to six.

[0013] On the other hand, the present invention provides a method for adjusting the axial balance force of a canned motor pump, which comprises the following steps:

[0014] Step 1: When repairing the canned motor pump, assemble all the parts of the canned motor pump except the volute;

[0015] Step 2: placing a lead plate on the inner side of the volute, reinstalling the volute, removing the volute, and flattening the lead plate using the volute and the impeller;

[0016] Step 3, making a sample according to the shape and thickness of the lead plate after being flattened;

[0017] Step 4, using the height of the sample plate, first subtract the amount of leakage of the rotor component of the shielded pump, and then subtract half of the sum of the clearances of the front and rear thrust plates and the stator end sliding bearing to obtain a determined height;

[0018] Step 5, using the determined height as the height of the spoiler, making a plurality of spoilers, and welding the plurality of spoilers evenly to the inner side of the volute, and reinstalling the volute;

[0019] Step six, conduct a pump hydraulic test and adjust the height of the spoiler again according to the hydraulic balance of the shielded pump rotor components.

[0020] Optionally, in step 2, the width of the lead plate before extrusion is less than three millimeters.

[0021] Optionally, in step five, the width of the spoiler is five to eight millimeters.

[0022] By means of the above technical solution, the present invention has at least the following advantages:

[0023] After various methods of adjusting axial balance have failed (such as cold welding to repair the accuracy of the front and rear rings, adjusting the diameter of the return hole, etc.), the pump chamber structure of the shielded pump adopts the method of adding multiple annular evenly distributed spoilers in the gap between the front of the impeller and the volute to increase the resistance of liquid leakage through the front ring of the impeller, thereby increasing the thrust of the inlet liquid on the front end of the impeller and adjusting the axial force of the rotor components to the normal position.

[0024] This method is suitable for single-stage pumps with large flow and head, where the axial force adjustment is difficult. Generally, the flow rate is greater than 150m 3 After adding a spoiler at a predetermined position on the inner side of the volute, adjusting the height of the spoiler can significantly affect the axial hydraulic balance of the rotor components, thereby quickly and efficiently restoring the performance of the canned motor pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1An axial cross-sectional view of a pump chamber structure of a canned motor pump provided by an embodiment of the present invention;

[0026] Figure 2 It is a three-dimensional diagram of the volute;

[0027] Figure 3 This is a schematic diagram of the position of the inference disk in the shielded pump.

[0028] The reference numerals in the drawings of the specification include: volute 1, spoiler 2, rotor component 3, impeller 4, wear-resistant disk 5, impeller front ring 6, impeller rear ring 7, thrust disk 8, stator end sliding bearing 9. DETAILED DESCRIPTION

[0029] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention application are described in detail below in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures, or characteristics in one or more embodiments may be combined in any suitable form.

[0030] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0031] like Figure 1 , Figure 2 As shown, on the one hand, an embodiment of the present invention provides a canned pump chamber structure, which includes: a volute 1 and a plurality of spoilers 2;

[0032] The plurality of spoilers 2 are evenly distributed in an annular shape on the inner side surface of the volute 1 .

[0033] The advantages of the shielded pump chamber structure are as follows:

[0034] After various methods of adjusting axial balance fail (such as cold welding to repair the accuracy of the front and rear rings, adjusting the diameter of the return hole, etc.), the pump chamber structure of the shielded pump adopts the method of adding multiple annular evenly distributed spoilers 2 in the gap opposite to the volute 1 in front of the impeller 4, so as to increase the resistance of liquid leaking through the front ring of the impeller 4, thereby increasing the thrust of the inlet liquid on the front end of the impeller 4, and adjusting the axial force of the rotor component 3 to the normal position.

[0035] This method is suitable for single-stage pumps with large flow and head, where the axial force adjustment is difficult. Generally, the flow rate is greater than 150m 3 After adding a spoiler 2 at a predetermined position on the inner side of the volute 1, adjusting the height of the spoiler 2 can significantly affect the axial hydraulic balance of the rotor component 3, thereby quickly and efficiently restoring the performance of the canned motor pump.

[0036] In the technical solution of the present invention, the canned motor pump chamber structure is adopted, so that the canned motor pump can be repaired in multiple ways and the maintenance effect is more intuitive.

[0037] Specifically, in the prior art, each component that makes up the shielded pump undergoes strict inspection before leaving the factory to obtain a high processing accuracy, and a qualified product can be obtained after assembly. However, the material medium of polysilicon enterprises contains silicon powder, which causes serious scouring to the components that ensure the "hydraulic balance" of the shielded pump (key parts such as the impeller front ring 6, the impeller rear ring 7, and the wear-resistant disk 5), and the dimensional accuracy of some thin-walled parts and grooves cannot be fully restored. At this time, the maintenance and adjustment of the pump at the maintenance site will be in trouble. That is, everything that can be repaired has been repaired, but the axial force still cannot be adjusted to meet the requirements, and there is nothing to be done. The pump chamber structure of the shielded pump takes a different approach and solves the problems in the prior art by installing multiple spoilers 2.

[0038] like Figure 2 As shown, in a specific embodiment, the number of the spoilers 2 is four to six.

[0039] In this embodiment, specifically, four to six spoilers 2 are evenly welded in an annular manner on the inner side of the volute 1. During the rotation of the impeller 4, the impeller 4 rotates relative to the spoiler 2. The liquid leaking through the front ring of the impeller 4 is blocked by multiple spoilers 2, and the flow rate is slowed down. Therefore, the amount of liquid passing through the front ring of the impeller 4 per unit time is reduced, and the liquid pressure at the inlet of the shielded pump is increased, thereby increasing the thrust on the front end of the impeller 4, so that the axial hydraulic balance of the rotor component 3 returns to normal.

[0040] On the other hand, the present invention provides a method for adjusting the axial balance force of a canned motor pump, which comprises the following steps:

[0041] Step 1: When repairing the canned motor pump, assemble all the canned motor pump components except the volute 1 in place;

[0042] Step 2: placing a lead plate on the inner side of the volute 1, reinstalling the volute 1, removing the volute 1, and using the volute 1 and the impeller 4 to flatten the lead plate, wherein the width of the lead plate before being squeezed is less than three millimeters;

[0043] Step 3, making a sample according to the shape and thickness of the lead plate after being flattened;

[0044] Step 4: Use the height of the template to first subtract the amount of the shielded pump rotor component 3, and then subtract half of the total clearance between the front and rear thrust plates 8 and the stator end sliding bearing 9 (such as Figure 3 As shown), the height is determined;

[0045] Step 5, using the determined height as the height of the spoiler, making a plurality of spoilers 2, wherein the width of the spoiler 2 is five to eight millimeters, and welding the plurality of spoilers 2 evenly to the inner side of the volute 1, and then reinstalling the volute 1;

[0046] Step six, conduct a pump hydraulic test and adjust the height of the spoiler 2 again according to the hydraulic balance of the shielded pump rotor component 3.

[0047] In the prior art, when the shielded pump runs for a long time, the gap between the impeller 4 and the volute 1 ring is worn by particles, and the gap between the impeller 4 and the back wear plate is also worn by particles, resulting in unstable hydraulic balance of the rotor component 3. For some shielded pumps with large head and large flow, the size of the repair equipment parts cannot restore the rotor axial balance force at one time, and repeated tests are required, and each test will cause damage to expensive spare parts.

[0048] However, after using this method, the following beneficial effects will be produced:

[0049] 1. Added ways to repair shielded pumps:

[0050] 2. No need to repeatedly replace expensive spare parts, the height of the spoiler 2 can be adjusted according to the state of "hydraulic balance" on the water test bench;

[0051] 3. Greatly improve maintenance efficiency and avoid the material replacement process when repeatedly offline;

[0052] 4. Shorten the maintenance time and save the time of repeated offline maintenance of the pump (about 8 to 12 hours of maintenance time / time);

[0053] 5. Reduce maintenance costs and save the cost of repeated offline maintenance of the pump (about 20,000 to 33,000 spare parts costs per time);

[0054] 6. Using this maintenance method, the axial force of the shielded pump is tested and adjusted on the test bench about 10 times per year, saving more than 500,000 yuan in spare parts costs each year, avoiding dangerous operations of material replacement, and providing great support and guarantee for the company's production.

[0055] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for adjusting the axial balance force of a canned motor pump, characterized in that: The pump chamber structure of the canned motor pump comprises: snail shell; A plurality of spoilers, wherein the plurality of spoilers are evenly distributed in an annular shape on the inner side surface of the volute; The method for adjusting the axial balance force of the canned motor pump comprises the following steps: Step 1: When repairing the canned motor pump, assemble all the parts of the canned motor pump except the volute; Step 2: placing a lead plate on the inner side of the volute, reinstalling the volute, removing the volute, and flattening the lead plate using the volute and the impeller; Step 3, making a sample according to the shape and thickness of the lead plate after being flattened; Step 4, using the height of the sample plate, first subtract the amount of leakage of the rotor component of the shielded pump, and then subtract half of the total clearance of the front and rear thrust plates and the stator end sliding bearing to obtain a determined height; Step 5, using the determined height as the height of the spoiler, making a plurality of spoilers, and welding the plurality of spoilers evenly to the inner side surface of the volute, and reinstalling the volute; Step six, conduct a pump hydraulic test and adjust the height of the spoiler again according to the hydraulic balance of the shielded pump rotor components.

2. The method for adjusting the axial balance force of a canned motor pump according to claim 1, characterized in that: The number of the spoilers is four to six.

3. The method for adjusting the axial balance force of a canned motor pump according to claim 1, characterized in that: In step 2, the width of the lead plate before being extruded is less than three millimeters.

4. The method for adjusting the axial balance force of a canned motor pump according to claim 1, characterized in that: In step five, the width of the spoiler is five to eight millimeters.

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