End-suction water inlet structure and centrifugal pump

Abstract

An end-suction inlet structure and centrifugal pump include a cylindrical inlet section with radially arranged ribs on the inner wall of the inlet section. The ribs extend axially, and their axial cross-section is a symmetrical airfoil-shaped teardrop shape. This invention uses ribs with a symmetrical airfoil-shaped teardrop cross-section in the inlet section of a backpack fire pump, which guides flow and reduces turbulence. This stabilizes the fluid flow field entering the first-stage impeller of the end-suction multistage pump, thereby improving the operational stability and efficiency of the end-suction multistage pump.

Description

Technical Field

[0001] This utility model relates to the field of centrifugal pumps, specifically to an end-suction water inlet structure and a centrifugal pump. Background Technology

[0002] Currently, most mainstream backpack fire pumps on the market do not have baffles installed at the inlet. This makes it easy for liquid to enter the pump impeller and cause impacts due to the direction being perpendicular to the impeller inlet, resulting in a large number of bubbles. This affects the pump's suction performance and leads to a decrease in pump performance.

[0003] Although some water pumps are equipped with baffles, their structures are conventional plate-shaped with steep tail transitions, causing premature separation of the liquid boundary layer from the airfoil surface, resulting in significant turbulence. This not only disrupts flow field stability but also causes energy loss, directly leading to increased flow fluctuations and vibrations, failing to meet the flow stability requirements of firefighting operations. Furthermore, it significantly reduces pump efficiency and affects the reliability of centrifugal pumps / fire pumps. Summary of the Invention

[0004] This invention aims to solve existing problems by providing an end-suction water inlet structure and a centrifugal pump.

[0005] To achieve the above objectives, the present invention provides an end-suction water inlet structure, including a cylindrical water inlet section, the inner wall of which is provided with a plurality of radially arranged ribs; the ribs extend axially, and their axial cross-section is symmetrical wing-shaped teardrop.

[0006] Among them, the leading edge of the symmetrical wing-shaped teardrop faces the direction of water inflow, and the width of the front section is relatively large; the trailing edge faces away from the direction of water inflow, and the width of the rear section is relatively small.

[0007] The rear edge of the stiffening plate has several notches.

[0008] Among them, several gaps are distributed radially.

[0009] The gap is triangular in shape.

[0010] Among them, the inner ends of several stiffening plates are respectively connected to bearing seats.

[0011] Among them, several stiffening plates are evenly distributed along the circumference.

[0012] This utility model also provides a centrifugal pump, the pump cover of which includes any of the aforementioned end-suction water inlet structures.

[0013] Compared with the existing technology, this utility model sets up a symmetrical wing-shaped teardrop-shaped stiffener in the water inlet of the backpack fire pump, which plays a role in guiding the flow and reducing turbulence. This can stabilize the fluid flow field entering the first stage impeller of the end-suction multistage pump, thereby improving the operational stability of the end-suction multistage pump and also improving its efficiency.

[0014] The notch at the end of the stiffener plate can reduce / eliminate the flow separation caused by the outer peripheral stiffener plate of the sliding bearing body, effectively reducing energy loss. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the pump cover structure;

[0016] Figure 2 This is a cross-sectional view of the pump cover;

[0017] Figure 3 for Figure 2 Sectional view of section AA;

[0018] Figure 4 This is a schematic diagram of the structure of the notch;

[0019] Figure 5 This is a schematic diagram of a multistage centrifugal pump.

[0020] See attached diagram: 1. Water inlet; 2. Rib plate; 3. Bearing housing; 4. Notch; 5. Pump cover; 6. Pump shaft; 7. Impeller. Detailed Implementation

[0021] The present invention will now be further described with reference to the accompanying drawings.

[0022] See Figures 1 to 4 , Figures 1 to 4 This embodiment shows one example of the present invention, which is a pump cover. As the end suction water inlet structure of a centrifugal pump, it mainly includes a cylindrical water inlet section. The water inlet section has a through opening facing the direction of water flow. The annular inner wall of the water inlet section is connected to the bearing seat in the middle by six radially arranged ribs. The ribs are evenly distributed along the circumference and form an included angle of 120° with each other.

[0023] The stiffening slab extends axially, and its axial cross-section is a symmetrical, teardrop-shaped flange. Further, see... Figure 3 The symmetrical teardrop-shaped airfoil has its leading edge facing the water inlet direction and its trailing edge facing away from the water inlet direction. The teardrop shape, which is larger at the front and smaller at the rear, effectively prevents turbulence from forming at the tail of the airfoil while simultaneously creating turbulence for the liquid entering the pump.

[0024] Further, see Figure 2 and Figure 4The rear edge of the stiffener has two notches, which are distributed radially. The notches are triangular, with the apex facing the water inlet direction and the base facing away from the water inlet direction. The notches can reduce or eliminate liquid flow separation.

[0025] The reason why fluid detaches from the stiffener is that the inertial force at that point is greater than the viscous force, thus causing the fluid to detach. When the fluid is about to detach, the fluid on both sides of the stiffener is made to merge at the tail gap, which can increase the mutual attraction of the fluid on the left and right sides of the stiffener, thereby reducing the influence of the inertial force and reducing or eliminating the detachment phenomenon that is common at the tail of ordinary straight stiffeners.

[0026] See Figure 5 Another embodiment of this utility model provides a portable fire pump, which is a multi-stage centrifugal pump, including a pump cover and multiple intermediate sections equipped with impellers. The pump cover adopts any of the above-mentioned symmetrical airfoil type end-suction multi-stage pump inlet structures with tail fin openings. Its working principle and technical effects are the same as those of the aforementioned embodiments, and therefore will not be described in detail.

[0027] Its bearing housing is rotatably connected to the pump shaft of the centrifugal pump through the bearing. The shaft body drives several impellers to rotate synchronously in the circumferential direction through the shaft sleeve, so that the liquid entering from the liquid inlet section undergoes centrifugal motion, thereby realizing the operation of the centrifugal pump.

[0028] The embodiments of this utility model have been described above with reference to the accompanying drawings and examples. The structures given in the embodiments do not constitute a limitation on this utility model. Those skilled in the art can make adjustments as needed, and various modifications or variations within the scope of the appended claims are all within the scope of protection.

Claims

1. An end suction intake structure, characterized by: It includes a cylindrical water inlet, and the inner wall of the water inlet is provided with several radially arranged stiffeners; The stiffening plate extends along the axial direction, and its axial cross section is symmetrical wing-shaped teardrop.

2. The end suction water intake structure of claim 1, wherein: The symmetrical teardrop-shaped wing has its leading edge facing the water inlet direction and its trailing edge facing away from the water inlet direction.

3. The end suction water entry structure of claim 1 or 2, wherein: The rear edge of the stiffening plate has several notches.

4. The end suction water intake structure of claim 3, wherein: Several gaps are distributed radially.

5. The end suction water entry structure of claim 3, wherein: The gap is triangular.

6. The end suction water entry structure of claim 1 or 2, wherein: The inner ends of several stiffening plates are respectively connected to bearing seats.

7. The end suction water entry structure of claim 1 or 2, wherein: The ribs are evenly distributed along the circumference.

8. A centrifugal pump characterized by: Its pump cover includes the end-suction water inlet structure as described in any one of claims 1-7.

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