CN216842401U - Anti cavitation of festival segmentation multistage pump loses device - Google Patents

Abstract

The utility model discloses a festival segmentation multistage pump anti-cavitation device, including the main shaft, the main shaft is installed on the pump body, main shaft side end face has set gradually bearing body, filler sleeve, scroll cover and primary impeller, the filler sleeve is installed the filler gland with the adjacent one end side end face of bearing body, the filler sleeve is provided with the filler ring with the adjacent one end side end face of scroll cover, filler ring side end face is equipped with the one end of drainage high-pressure pipe, drainage high-pressure pipe side end face installs the coupling, drainage high-pressure pipe is from the fixedly connected with high-pressure water pipe of filler ring one end, high-pressure water pipe side end face installs the valve accuse device, filler sleeve side end face is provided with the sealing filler, scroll cover side end face installs the inlet tube, be provided with the suction chamber in the inlet tube, primary impeller has seted up the primary impeller entry with the adjacent one side of scroll cover, and guide vanes are arranged outside the first-stage impeller. The utility model discloses the anti cavitation of multistage pump ability has effectively been improved.

Description

Anti cavitation of festival segmentation multistage pump loses device

Technical Field

The utility model relates to a machinery multistage pump technical field specifically is an anti cavitation device of festival segmentation multistage pump.

Background

The cavitation phenomenon of the centrifugal pump means that when the pressure at the inlet of an impeller of the pump is lower than the saturated vapor pressure of liquid at the ambient temperature, a large amount of vapor in the liquid escapes and is mixed with gas to form a plurality of small bubbles. When the gas reaches the high-pressure area, steam is condensed, bubbles are broken, the bubbles disappear to generate local vacuum, liquid particles quickly impact to the centers of the bubbles, the particles collide with each other, and high local pressure is generated. When the centrifugal pump generates cavitation, shock waves which harm an impeller and a pump shell are formed, and under the combined action of trace dissolved oxygen in liquid to chemical corrosion of metal, the surface of the centrifugal pump can generate spots and cracks and even fall off gradually in a spongy manner after a certain time; when cavitation occurs, noise is also generated, and the pump body is vibrated; meanwhile, the apparent density of the liquid is reduced due to the generation of steam, so that the actual flow rate, the outlet pressure and the efficiency of the liquid are remarkably reduced, and the liquid can not be output at all in severe cases.

At present, two methods are mainly used for obtaining the lower required cavitation allowance NPSHr by the sectional type multi-stage pump: firstly, the size of the inlet of the first-stage impeller and the size of the water suction chamber are increased, and the geometric shape of the blade at the inlet of the impeller is changed. The method can improve the cavitation of the pump to a certain extent, reduce the necessary cavitation allowance NPSHr of the pump, but when the cavitation specific speed C of the pump is more than 1000, the method can not continuously obtain better cavitation performance, the efficiency of the water pump is obviously reduced and is not compensated because the inlet of the impeller is continuously enlarged and the geometric shape of the blade at the inlet of the impeller is changed, and the other method is that the first-stage impeller adopts a double-suction impeller structure, the method can obtain better cavitation performance than a single-suction impeller, but the scheme makes the structure of the pump complicated, increases the whole size and the manufacturing difficulty of the pump, and obviously improves the manufacturing cost and the use cost of the pump.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an anti cavitation device of festival segmentation multistage pump to solve the problem that proposes among the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme: a section type multi-stage pump cavitation-resistant device comprises a main shaft, the main shaft is arranged on a pump body, a bearing body, a packing shaft sleeve, a spiral sleeve and a primary impeller are sequentially arranged on the side end face of the main shaft, a packing gland is arranged on the end face of one end of the packing shaft sleeve adjacent to the bearing body, a packing ring is arranged on the end face of one end of the packing shaft sleeve adjacent to the spiral sleeve, one end of a drainage high-pressure pipe is arranged on the side end face of the packing ring, a pipe joint is arranged on the side end face of the drainage high-pressure pipe, one end of the drainage high-pressure pipe, which is far away from the packing ring, is fixedly connected with a high-pressure water pipe, the side end surface of the high-pressure water pipe is provided with a valve control device, the end face of the side of the filler shaft sleeve is provided with a sealing filler, the end face of the side of the spiral sleeve is provided with a water inlet pipe, be provided with the room that absorbs water in the inlet tube, the first impeller entry has been seted up to first impeller and adjacent one side of helical casing, first impeller externally mounted has the stator.

Preferably, in this embodiment, the first-stage impeller is connected to the pump body on a side away from the screw sleeve.

Preferably, the packing ring spans the connection point of the packing shaft sleeve and the screw sleeve, and the packing ring sleeves the connection point of the packing shaft sleeve and the screw sleeve.

Preferably, in this embodiment, the packing is located between the packing gland and the packing ring on the side end surface of the packing sleeve.

Preferably, in this embodiment, the inlet of the first-stage impeller is communicated with the water suction chamber.

Compared with the prior art, the beneficial effects of the utility model are as follows:

1. the utility model discloses a lead one high pressure water to the seal chamber of water pump from pump body high pressure side or pump house high pressure water pipe, the drilled packing ring is aimed at in the high pressure pipe export, sets up the flow and the pressure that the valve accuse device controlled the high pressure water on the high pressure water pipe.

2. The utility model discloses increase a swivel nut between first order impeller entry and sealed chamber, the swivel nut is located between first order impeller and the axle sleeve that packs, and the screw thread is revolved to available left and right hand rule and is judged: the directional pump shaft direction of rotation of four fingers, the directional low pressure side of thumb, the right hand satisfies then the screw thread direction gets the positive rotation, the left hand satisfies then the screw thread direction gets the derotation, the scroll cover is used for guiding the even first-stage impeller entry of the flow direction of high pressure water in the sealed cavity, the scroll cover follows the rotatory in-process of pump shaft, further for the high pressure water increase energy of guide, obtain higher pressure, what the scroll cover water conservancy diversion came out has pressurized water and pump inlet velocity of flow, the flow state homogenization, increase impeller entrance energy, improve the entry flow state, thereby improve pump cavitation erosion performance, reduce the must cavitation surplus of pump.

3. The packing ring for packing sealing is arranged on the innermost side of the sealing cavity, and the packing ring is arranged on the innermost side, so that high-pressure water can smoothly reach the inlet of the spiral sleeve, and the energy loss is small.

Drawings

FIG. 1 is a schematic structural view of the installation of the anti-cavitation device and the pump body of the sectional multi-stage pump according to the present invention;

fig. 2 is the sectional structure view of the anti-cavitation device of the sectional type multistage pump of the present invention.

In the figure: the device comprises a pipe joint 1, a high-pressure water pipe 2, a valve control device 3, a drainage high-pressure pipe 4, a packing shaft sleeve 5, a bearing body 6, a packing gland 7, a main shaft 8, a sealing packing 9, a first-stage impeller inlet 10, a water suction chamber 11, a water inlet pipe 12, a spiral sleeve 13, a first-stage impeller 14, a guide vane 15 and a packing ring 16.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 1-2, the present invention provides an embodiment: a section type multi-stage pump cavitation-resistant device comprises a main shaft 8, wherein the main shaft 8 is arranged on a pump body, the end face of the main shaft 8 is sequentially provided with a bearing body 6, a packing shaft sleeve 5, a spiral sleeve 13 and a first-stage impeller 14, the end face of the packing shaft sleeve 5, which is adjacent to the bearing body 6, is provided with a packing gland 7, the end face of the packing shaft sleeve 5, which is adjacent to the spiral sleeve 13, is provided with a packing ring 16, the end face of the packing ring 16 is provided with one end for guiding a high-pressure pipe 4, the end face of the guiding high-pressure pipe 4 is provided with a pipe joint 1, one end of the guiding high-pressure pipe 4, which is far away from the packing ring 16, is fixedly connected with a high-pressure water pipe 2, the end face of the high-pressure water pipe 2 is provided with a valve control device 3, the end face of the packing shaft sleeve 5 is provided with a sealing packing 9, the end face of the spiral sleeve 13 is provided with a water inlet pipe 12, a water suction chamber 11 is arranged in the water inlet 12, and the adjacent to the first-stage impeller 14 and the spiral sleeve 13 is provided with a first-stage impeller inlet 10, the first-stage impeller 14 is externally provided with guide vanes 15.

In the present exemplary embodiment, the primary impeller 14 is connected to the pump body on the side facing away from the screw sleeve 13.

Wherein, a seal cavity is formed between the first-stage impeller 14 and the shaft seal of the main shaft 8 in the multi-stage pump, the spiral sleeve 13 is arranged between the first-stage impeller 14 and the seal cavity, and the rotation direction of the spiral sleeve 13 is judged by a left-hand or right-hand rule, and the judging method specifically comprises the following steps: the four fingers point to the rotation direction of the main shaft 8, the thumb points to the low-pressure water side, the left hand meets the requirement that the thread direction of the spiral sleeve 13 is in a reverse rotation mode, and the right hand meets the requirement that the thread direction of the spiral sleeve 13 is in a forward rotation mode.

Specifically, the packing ring 16 spans the connection point of the packing sleeve 5 and the screw sleeve 13, and the packing ring 16 encases the connection point of the packing sleeve 5 and the screw sleeve 13.

Wherein, a high pressure water pipe leads a stream of high pressure water to a seal cavity of the water pump, the high pressure water pipe is aligned to the packing ring 16 through the drainage high pressure pipe, and the valve control device 3 on the high pressure water pipe 2 can control the flow and the pressure of the high pressure water.

Furthermore, the sealing packing 9 is positioned between the packing gland 7 and the packing ring 16 on the end face of the side of the packing shaft sleeve 5, and the packing ring 16 is positioned on the innermost side of the sealing cavity, so that high-pressure water can smoothly reach the inlet and the outlet of the spiral sleeve 13, and the capacity loss of the high-pressure water is effectively reduced.

Further, the first-stage impeller inlet 10 communicates with the suction chamber 11.

The working principle is as follows: a spiral sleeve 13 is additionally arranged between a first-stage impeller inlet 10 and a sealing cavity, the spiral sleeve 13 is positioned between a first-stage impeller 14 and a 5 packing shaft sleeve, the spiral sleeve 13 is used for guiding high-pressure water in the sealing cavity to uniformly flow to the first-stage impeller inlet 10, the spiral sleeve 13 further increases energy for the guided high-pressure water in the rotation process of a pump shaft to obtain higher pressure, the high-pressure water guided out by the spiral sleeve 13 is homogenized with the flow velocity and the flow state of a pump inlet, the energy at the impeller inlet is increased, the flow state of the inlet is improved, the pump cavitation performance is improved, the necessary cavitation allowance of the pump is reduced, meanwhile, a jet of high-pressure water is guided to the sealing cavity of the water pump from the high-pressure side of a pump body or a high-pressure water pipe 2 of a pump room, a high-pressure pipe outlet 2 is aligned to a packing ring 16 through a drainage high-pressure pipe 4, the flow and the pressure of the high-pressure water are controlled by arranging a valve control device 3 on the high-pressure pipe, and the packing ring 16 sealed at the innermost side of the sealing cavity, the packing ring 16 is arranged at the innermost side, so that high-pressure water can smoothly reach the inlet of the spiral sleeve 13, and the energy loss of the high-pressure water is further reduced.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (5)

1. The utility model provides an anti cavitation device of festival segmentation multistage pump, includes main shaft (8), its characterized in that: the pump is characterized in that the main shaft (8) is installed on the pump body, the side end face of the main shaft (8) is sequentially provided with a bearing body (6), a packing shaft sleeve (5), a spiral sleeve (13) and a primary impeller (14), the side end face of one end, adjacent to the bearing body (6), of the packing shaft sleeve (5) is provided with a packing gland (7), the side end face of one end, adjacent to the spiral sleeve (13), of the packing shaft sleeve (5) is provided with a packing ring (16), the side end face of the packing ring (16) is provided with one end of a drainage high-pressure pipe (4), the side end face of the drainage high-pressure pipe (4) is provided with a pipe joint (1), one end, away from the packing ring (16), of the drainage high-pressure pipe (4) is fixedly connected with a high-pressure pipe (2), the side end face of the high-pressure pipe (2) is provided with a valve control device (3), the side end face of the packing shaft sleeve (5) is provided with a sealing filler (9), the side end face of the spiral sleeve (13) is provided with a water inlet pipe (12), be provided with water suction chamber (11) in inlet tube (12), first impeller entry (10) have been seted up to first impeller (14) and adjacent one side of helical casing (13), first impeller (14) externally mounted has stator (15).

2. The apparatus of claim 1, wherein: and one side of the primary impeller (14) departing from the spiral sleeve (13) is connected with the pump body.

3. The apparatus of claim 1, wherein: the packing ring (16) spans a connection point of the packing shaft sleeve (5) and the spiral sleeve (13), and the packing ring (16) sleeves the connection point of the packing shaft sleeve (5) and the spiral sleeve (13).

4. The apparatus of claim 1, wherein: the sealing packing (9) is positioned between the packing gland (7) and the packing ring (16) on the side end face of the packing shaft sleeve (5).

5. The apparatus of claim 1, wherein: the inlet (10) of the first-stage impeller is communicated with a water inlet pipe (12).

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