Non-clogging two-phase flow semi-open type sewage pump impeller

Abstract

The utility model relates to a non-clogging two-phase flow semi-open type sewage pump impeller, which comprises an impeller body, two-to-four blades are arranged on the impeller body; when the number of the blades is small, wrap angles are increased, inlet edges of the blades are of blade sweepback structures, and back blades are arranged on the back face of the impeller body; the area change between the impeller inlet area and the impeller outlet area is uniformly and progressively increased; the impeller body, the blades and the back blades are integrally formed. By means of the innovative design of the impeller, accumulation and blockage of solids and impurities in the pump are effectively avoided, and therefore continuous and stable operation of the sewage pump is guaranteed. Due to the design of the impeller, the hydrodynamic characteristics are optimized, the impact of bubbles on parts in the pump is reduced, the anti-cavitation capacity of the sewage pump is remarkably improved, and the service life of the pump is prolonged. According to the utility model, various solid-liquid mixtures can be smoothly treated, meanwhile, the energy loss is reduced, and the overall working efficiency is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a sewage pump impeller, concretely relates to a half-open type sewage pump impeller of two-phase flow without blockage, which has good performance, good cavitation performance and stable comprehensive performance. BACKGROUND

[0002] The sewage pump is generally used in municipal sewage, industrial wastewater treatment, mine drainage and other fields, and the medium conveyed mainly includes solid-liquid mixed fluid containing solid particles, fiber material, sludge and other complex components. The traditional sewage pump impeller design is often subject to blockage problems due to the narrow flow channel structure, and needs to be frequently stopped for maintenance, which seriously affects the operation efficiency and increases the maintenance cost. Although the current market designs of the non-blocking impeller have certain advantages in terms of anti-blocking performance, they still face problems such as low efficiency and insufficient cavitation resistance. With the increasing strictness of the society to energy saving and environmental protection, and the significant increase in the treatment of high-concentration particles, long-fiber impurities and other medium conditions, the existing sewage pump design faces challenges in balancing the anti-blocking performance, improving the working efficiency and ensuring the long-term stable operation reliability. More importantly, the current design scheme mainly relies on traditional experience, and lacks in-depth understanding and systematic application of the interaction mechanism between solid-liquid two phases, which directly leads to unstable dynamic performance of the pump and difficulty in meeting the complex and variable application requirements. Therefore, it is an urgent technical problem to explore a new type of sewage pump design that can effectively prevent blockage and balance high-efficiency operation and long-term reliability. SUMMARY

[0003] In view of the above problems, the main purpose of the utility model is to provide a half-open type sewage pump impeller of two-phase flow without blockage, which has good performance, good cavitation performance and stable comprehensive performance.

[0004] The utility model solves the above technical problems through the following scheme: a half-open type sewage pump impeller of two-phase flow without blockage, which comprises: an impeller body, the impeller body is provided with 2-4 blades; when the number of blades is small, the wrap angle is increased, the inlet edge of the blade is a backward swept structure, and the back surface of the impeller body is provided with a back blade; the area change between the impeller inlet area F1 and the impeller outlet area F2 is uniformly increased; the impeller body, the blade and the back blade are integrally formed.

[0005] The back blade can reduce the airflow separation on the back surface of the main blade, improve the stability of fluid flow, prevent turbulence and vibration, balance the axial force, reduce the load of the main blade, reduce wear and tear, and prolong the service life.

[0006] In the specific embodiment of the utility model, the area change between the impeller inlet area F1 and the impeller outlet area F2 is uniformly increasing, and

[0007] In the specific embodiment of the utility model, the streamline radius R1 of the impeller front cover plate is greater than or equal to 25 mm.

[0008] In the specific embodiment of the utility model, the back blade includes 5-12 pieces.

[0009] In the specific embodiment of the utility model, when the pump body outlet diameter is 32-250 mm (including 250 mm) and the number of blades is 2, the included angle φ is 160°-230°.

[0010] In the specific embodiment of the utility model, when the pump body outlet diameter is 250-500 mm (not including 250 mm) and the number of blades is 3, the included angle φ is 150°-210°.

[0011] In the specific embodiment of the utility model, when the pump body outlet diameter is > 500 mm and the number of blades is 3 or 4, the included angle φ is 120°-180°.

[0012] The positive progress effect of the utility model lies in: compared with the common similar technology, the half-open type sewage pump impeller without blockage provided by the utility model has the following advantages:

[0013] (1) The anti-blocking performance is significantly improved: when dealing with solid-liquid mixed fluid containing solid particles, fiber materials and sludge, etc., the traditional sewage pump often causes blockage due to improper impeller design. The innovative impeller design of the utility model effectively avoids the accumulation and blockage of these solids and impurities in the pump, thereby ensuring the continuous and stable operation of the sewage pump.

[0014] (2) Enhance the anti-cavitation ability: when conveying medium containing bubbles, the traditional sewage pump is prone to cavitation phenomenon, which not only affects the performance of the pump, but also may cause damage to the pump body. The impeller design of the utility model optimizes the fluid dynamics characteristics, reduces the impact of bubbles on the internal parts of the pump, significantly improves the anti-cavitation ability of the sewage pump, and prolongs the service life of the pump.

[0015] (3) Improve the passability and efficiency: through fine flow channel design and optimized impeller structure, the sewage pump of the utility model shows better passability when conveying complex fluid, which can smoothly handle various solid-liquid mixtures, while reducing energy loss and improving overall working efficiency. This not only reduces energy consumption, but also improves the economic efficiency of the pump operation.

[0016] (4) Maintenance is convenient: compared with the fully enclosed impeller, the maintenance and cleaning of the sewage pump of the utility model is more convenient, the maintenance cost and time are reduced, and the availability and reliability of the equipment are improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is one of the whole structure schematic diagrams of the utility model (the front of line drawing).

[0018] Figure 2 It is the second whole structure schematic diagram of the utility model (the front of effect drawing).

[0019] Figure 3 It is the third whole structure schematic diagram of the utility model (the back of effect drawing).

[0020] Figure 4 It is the fourth whole structure schematic diagram of the utility model (drawing front and back cover plate streamline).

[0021] Figure 5 It is the fifth whole structure schematic diagram of the utility model (drawing front and back cover plate streamline).

[0022] Figure 6 It is the comparison diagram of the inlet edge and common technology of the utility model.

[0023] Figure 7 It is the comparison diagram of the flow passage area and common technology of the utility model.

[0024] The following is the name corresponding to the mark in the utility model:

[0025] Impeller body 1, blade 2, blade sweepback structure 3, back blade 4. DETAILED DESCRIPTION

[0026] The preferred embodiments of the utility model are given below in combination with the drawings to specifically describe the technical scheme of the utility model.

[0027] Figure 1 It is one of the whole structure schematic diagrams of the utility model (the front of line drawing), Figure 2 It is the second whole structure schematic diagram of the utility model (the front of effect drawing), Figure 3 It is the third whole structure schematic diagram of the utility model (the back of effect drawing), for example Figures 1-3 The utility model discloses a kind of no jamming two-phase flow semi-open sewage pump impellers, which includes: impeller body 1, 2-4 blades 2 are provided on impeller body 1;When the number of blade 2 is less, add wrap angle, the inlet edge of blade 2 is blade sweepback structure 3, the back of impeller body 1 is provided with back blade 4;Impeller body 1, blade 2 and back blade 4 are integrally formed.

[0028] The back blade includes 5-12 pieces, which can reduce the air flow separation of the back of the main blade, improve the stability of fluid flow, and prevent turbulence and vibration. The back blade can balance the axial force, reduce the load of the main blade, reduce wear and tear, and prolong the service life.

[0029] The inlet edge of the blade 2 is a back-swept structure 3, as shown in Figure 6 , where A is the back-swept blade, and B (dashed line) is the structure in the current common technology.

[0030] The design method of the above impeller mainly includes the following steps:

[0031] Step 1: Determine the design flow Q, design head H, speed n, and medium to be transported. In order to ensure better passing performance and better anti-cavitation performance, a few blades Z and a large inlet are used when designing the impeller, so the area of the impeller flow passage needs to be paid special attention. The specific speed n s = 70-280, and the value is determined as follows:

[0032] (1) Determine the impeller inlet diameter

[0033]

[0034] The value of k0 is 4.6-5.5, and the range of 4.6-5.5 includes 4.6 and 5.5;

[0035] (2) Determine the impeller outlet diameter and outlet width

[0036]

[0037] The value of 9.4-11.5 includes 9.4 and 11.5; the smaller the specific speed, the larger the coefficient;

[0038]

[0039] The above 1.8-2.4 includes 1.8 and 3.0, and the small pump takes a small value and the large pump takes a large value;

[0040] In the above formula:

[0041] D j — Impeller inlet diameter, (mm)

[0042] Q— Pump flow, (m 3 / s)

[0043] k0— Coefficient

[0044] n— Pump speed, (r / min)

[0045] D2 - impeller outlet diameter, (m)

[0046] n s - water pump specific speed, where

[0047] H - water pump design point head, (m)

[0048] Step two: determine the outlet angle

[0049] In order to ensure that the overall sewage pump does not exceed power, it is necessary to ensure that the head drop trend is steep. The outlet angle is generally selected between 13°-22°.

[0050] Step three: draw the front and rear cover plate streamline

[0051] As shown in Figure 4 R1 is the front cover plate streamline radius of the impeller, R2 is the rear cover plate streamline radius of the impeller, in order to ensure that the sewage pump has better passing performance, generally R1 is slightly larger, usually not less than 25mm, R2 is slightly smaller, generally according to the flow area to ensure its passing performance.

[0052] Step four: correct the impeller inlet and outlet area

[0053] After the impeller inlet and outlet width is designed, the impeller inlet area F1 and the impeller outlet area F2 can be obtained, if the area change between F1-F2 is uniform and increasing, and Then the next step can be taken, if it does not meet the requirements, the step one needs to be modified until it meets the requirements.

[0054] Step five: determine the wrap angle, blade number and blade inlet edge curve

[0055] The number of blades of the impeller is determined according to the pump body outlet diameter, generally 2-4 pieces, when determining the wrap angle, the blade extrusion and surface friction need to be considered, when the blade is less, the wrap angle should be appropriately increased, and the related value parameters are as follows:

[0056]

[0057]

[0058] In order to improve the flow characteristics, avoid dirt winding, and at the same time improve the anti-cavitation performance, the utility model discloses a blade sweepback design.

[0059] The following is a specific example: in the specific example of the utility model, the design flow is 350m 3 / h, the design head is 38 m, the rotating speed is 1475 r / min, the hub diameter is 76 mm, and the pump outlet diameter is 150 mm. The specific rotating speed is 110.

[0060] Step one:

[0061] (1) Determine the impeller inlet diameter

[0062] Take 220 mm

[0063] (2) Determine the impeller outlet diameter and outlet width Take 440 mm

[0064] Take 36 mm

[0065] Step two: Determine the outlet installation angle β2

[0066] The outlet installation angle β2 of the design scheme is 20°.

[0067] Step three: Draw the front and rear cover plate streamline

[0068] According to the relevant parameters of step one, the front and rear cover plate streamline of the case is determined, as shown in the following figure. Figure 5

[0069] Step four: Correct the impeller inlet and outlet area:

[0070] The impeller inlet and outlet area is checked, and the area change is shown in the following figure. The outlet area F2 / inlet area F1 of the scheme is F2 / F1=1.48, which meets the relevant design requirements, and the area change is uniform and increasing.

[0071] Step four: Determine the wrap angle, number of blades and blade inlet edge curve:

[0072] The outlet diameter of the scheme is 250 mm, according to Table 1., the number of blades is 2, the blade wrap angle is 220°, and the inlet edge curve is shown in the following figure.

[0073] (1) Parameter comparison

[0074]

[0075] (2) Comparison of axial section lines (see Figure 7 ): From the axial section line, the flow passage (C line in the figure) of the scheme is obviously larger than that of the existing scheme (D line in the figure), and the impeller of the scheme is not easy to be blocked, and the passing performance is good.

[0076] ​(3) Blade inlet edge shape comparison: the blade inlet edge shape of the scheme is designed as a blade sweepback type. The flow characteristics can be improved, dirt winding can be avoided, and the anti-cavitation performance can be improved.

[0077] The anti-blocking performance of the utility model is improved significantly: when the traditional sewage pump is used to treat solid-liquid mixed fluid containing solid particles, fiber materials and sludge, etc., the impeller is often designed improperly, which leads to blockage. The utility model effectively avoids the accumulation and blockage of these solids and impurities in the pump through the innovative impeller design, thereby ensuring the continuous and stable operation of the sewage pump.

[0078] The utility model has strong anti-cavitation ability: when conveying medium containing bubbles, the traditional sewage pump is prone to cavitation phenomenon, which not only affects the performance of the pump, but also may cause damage to the pump body. The impeller design of the utility model optimizes the fluid dynamics characteristics, reduces the impact of bubbles on the internal parts of the pump, significantly improves the anti-cavitation ability of the sewage pump, and prolongs the service life of the pump.

[0079] The utility model improves the passability and efficiency: through the fine flow channel design and optimized impeller structure, the sewage pump of the utility model shows better passability when conveying complex fluid, can smoothly handle various solid-liquid mixtures, reduces energy loss, and improves overall working efficiency. This not only reduces energy consumption, but also improves the operation economy of the pump.

[0080] The utility model is convenient to maintain: due to the adoption of semi-open design, compared with the fully enclosed impeller, the sewage pump of the utility model is more convenient to maintain and clean, reduces the maintenance cost and time, and improves the availability and reliability of the equipment.

[0081] The above shows and describes the basic principles and main features of the utility model and the advantages of the utility model. It should be understood by those skilled in the art that the utility model is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the utility model. Without departing from the spirit and scope of the utility model, the utility model can also have various changes and improvements, which all fall within the scope of the claimed utility model. The scope of protection of the utility model is defined by the appended claims and their equivalents.

Claims

1. A non-clog, two-phase flow semi-open impeller for a sewage pump, characterized in that: The non-clogging two-phase flow semi-open type drain pump impeller comprises an impeller body provided with 2-4 blades, the number of blades is small, and the wrap angle is increased, The inlet edge of the blade is a backward swept structure, and the back surface of the impeller body is provided with a back blade; The area change between the impeller inlet area F1 and the impeller outlet area F2 is uniformly increased; The impeller body, the blade and the back blade are integrally formed.

2. The non-clog, two-phase flow semi-open dirty-wastewater pump impeller of claim 1, wherein: The area change between the impeller inlet area F1 and the impeller outlet area F2 is uniformly increasing, and 3. The non-clog, two-phase flow semi-open dirty-wastewater pump impeller of claim 1, wherein: The streamline radius R1 of the impeller front cover plate is greater than or equal to 25 mm.

4. The non-clog, two-phase flow semi-open dirty-wastewater pump impeller of claim 1, wherein: The back blade comprises 5-12 pieces.

5. A non-clog, two-phase flow semi-open impeller for a sewage pump according to one of claims 1-4, characterized in that: When the pump body outlet diameter is 32-250 mm (including 250 mm), the number of blades is 2, and the wrap angle φ is 160°-230°.

6. A non-clog, two-phase flow semi-open impeller for a sewage pump according to one of claims 1-4, characterized in that: When the pump body outlet diameter is 250-500 mm (not including 250 mm), the number of blades is 3, and the wrap angle φ is 150°-210°.

7. A non-clog, two-phase flow semi-open impeller for a sewage pump according to one of claims 1-4, characterized in that: When the pump body outlet diameter is > 500 mm, the number of blades is 3 or 4, and the wrap angle φ is 120°-180°.

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