Bearing housing raw water cooled multi-stage high-pressure centrifugal pump

Abstract

This utility model discloses a multi-stage high-pressure centrifugal pump with bearing housing raw water cooling, which is a horizontal axial suction segmental design, including a pump housing assembly, a rotor assembly, a bearing assembly, and a sealing cover. The pump housing assembly includes a suction section housing, an intermediate section housing, and a discharge section housing connected in sequence. The key feature is that a sealing cover is provided at the rear end of the discharge section housing, forming a balance chamber between the sealing cover and the discharge section housing. A bearing assembly is provided at the rear end of the sealing cover, forming a sealing chamber between the sealing cover and the bearing assembly. A mechanical seal mechanism is provided on the rotating shaft within the sealing chamber. The bearing assembly contains a bearing body and a water-cooling chamber. The balance chamber receives the balance water discharged from the axial force balance mechanism and is connected to the sealing chamber. The sealing chamber and the water-cooling chamber are connected by a connecting pipe. The water-cooling chamber is connected to the working chamber of the first-stage impeller of the suction housing by a balance return water pipe. This utility model achieves raw water cooling for the mechanical seal mechanism and the bearing body.

Description

Technical Field

[0001] This utility model relates to an improved invention of a multi-stage high-pressure centrifugal pump, and more particularly to an improved invention of a bearing housing raw water-cooled multi-stage high-pressure centrifugal pump. Background Technology

[0002] Reverse osmosis (RO) is one of the mainstream seawater desalination methods in the world today, and its proportion in seawater desalination projects is increasing, especially in my country, where it accounts for over 80%. The three core technologies of RO seawater desalination are the permeation membrane, the high-pressure pump, and the energy recovery device. The high-pressure pump, one of the three core technologies, provides the seawater permeation membrane with pressures exceeding 6-12 MPa. Currently, the flow rate of a RO seawater desalination high-pressure pump with a daily processing capacity of 10,000 tons of seawater is 210-450 m³ / h, and the head is 550-700 m. For such medium-to-high flow rate high-pressure pumps, the pump efficiency can reach 75-81% when using a segmental multistage high-pressure centrifugal pump. Due to its simple structure, small size, light weight, and low price, this pump is suitable for RO seawater desalination projects.

[0003] According to the China Patent Network, the patent number is 201010543749.2, and the patent name is "Horizontal Axial Suction Segmental Multistage High-Pressure Centrifugal Pump". It discloses that the multistage high-pressure centrifugal pump adopts a horizontal axial suction segmental setting, supplemented by an axial force balancing mechanism, and the mechanical seal mechanism is cooled by raw water. Specifically, it relies on the balance water discharged from the axial force balancing mechanism for flushing and cooling, and the balance water is flushed through the balance return water pipe and then returned to the working chamber of the first impeller in the suction section housing after flushing the mechanical seal cover.

[0004] However, the cooling structure of the bearing housing is not disclosed. Traditional bearing housings usually use an external cooling structure, which uses external cooling water for cooling instead of raw water cooling. Furthermore, the external drainage design of the cooling water leads to increased energy consumption and increased costs. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a bearing housing raw water cooling multi-stage high-pressure centrifugal pump.

[0006] To solve the above-mentioned technical problems, this utility model adopts the following technical solution: This bearing-body raw water-cooled multi-stage high-pressure centrifugal pump is a horizontal axial suction segmental design, including a pump housing assembly, a rotor assembly, a bearing assembly, and a sealing cover. The pump housing assembly includes a suction section housing, an intermediate section housing, and a discharge section housing connected in sequence. The rotor assembly includes a first-stage impeller, a second-stage impeller, a rotating shaft, and an axial force balancing mechanism. The characteristic feature is that a sealing cover is provided at the rear end of the discharge section housing, forming a balancing cavity between the sealing cover and the discharge section housing. A bearing assembly is provided at the rear end of the sealing cover, forming a sealing cavity between the sealing cover and the bearing assembly. A mechanical seal mechanism is provided on the rotating shaft within the sealing cavity. The bearing assembly contains a bearing body and a water-cooling chamber. The balancing cavity receives the balancing water discharged from the axial force balancing mechanism and is connected to the sealing cavity. The sealing cavity and the water-cooling chamber are connected by a connecting pipe. The water-cooling chamber is connected to the working chamber of the first-stage impeller in the suction housing by a balancing return water pipe.

[0007] The sealing cover has a central flow channel, which connects the balance chamber and the sealing chamber.

[0008] The mechanical seal mechanism is a single-end face cartridge mechanical seal mechanism.

[0009] The bearing housing is equipped with a rolling ball bearing.

[0010] The axial force balancing mechanism includes a balancing drum, a balancing sleeve, and a balancing sleeve pressure plate.

[0011] The beneficial effects of this utility model are that the improved bearing housing raw water cooling multi-stage high-pressure centrifugal pump has an integrated design of the cooling medium circulation path. After the raw water flows out from the axial force balancing mechanism, it enters the sealing cavity of the mechanical seal mechanism, then passes through the water cooling chamber of the bearing assembly, and then, through the balance return water pipe, the heated cooling water is returned to the working chamber of the first impeller by utilizing the pressure difference. This makes full use of the cooling water to cool the mechanical seal mechanism and the bearing housing, reduces losses, and avoids cooling water pollution. Attached Figure Description

[0012] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings.

[0013] Figure 1 This is a schematic diagram of the structure of this utility model. Detailed Implementation

[0014] The accompanying drawings illustrate the structure of this utility model, and further details will be described below in conjunction with the drawings. In this embodiment, see the attached drawings. Figure 1This bearing housing is a water-cooled multi-stage high-pressure centrifugal pump with a horizontal axial suction segmental design. The corresponding liquid flow is axially suctioned and radially discharged. The axial inlet direction is parallel to the pump shaft centerline to ensure uniform fluid entry into the impeller and reduce flow losses. Specifically, it includes a pump housing assembly 1, a rotor assembly 2, a bearing assembly 3, and a sealing cover 4. The pump housing assembly 1 includes a suction section housing 11, an intermediate section housing 12, and a discharge section housing 13 connected in sequence. The rotor assembly 2 includes a first-stage impeller 21, a second-stage impeller 22, a shaft 23, and an axial force balancing mechanism 24. The rear end of the discharge section housing 13 is equipped with a sealing cover 4, which is connected to the discharge section housing 13. A balancing chamber 5 is formed between the outlet section and the housing 13. A bearing assembly 3 is provided at the rear end of the sealing cover 4, and a sealing chamber 6 is formed between the sealing cover 4 and the bearing assembly 3. A mechanical seal mechanism 7 is provided on the rotating shaft 23 in the sealing chamber 6. The bearing assembly 3 is provided with a bearing body 31 and a water-cooling chamber 32. The balancing chamber 5 receives the balancing water discharged from the axial force balancing mechanism 24, and the balancing chamber 5 is connected to the sealing chamber 6. The sealing chamber 6 and the water-cooling chamber 32 are connected by a connecting pipe 8. The water-cooling chamber 32 is connected to the working chamber of the first-stage impeller 21 of the suction housing by a balancing return water pipe 9. The balancing return water pipe 9 and the connecting pipe 8 are preferably stainless steel pipes to prevent seawater corrosion. The specific structure and working principle of the horizontal axial suction segmental multistage high-pressure centrifugal pump are existing technologies and will not be described in detail here.

[0015] The mechanical seal mechanism 7 and bearing body 31 of this utility model do not require external cooling water supply. They rely on the balance water discharged from the axial force balance mechanism 24 for flushing and cooling. Specifically, the pressure relief water (about 0.3 to 0.5 MPa) flows from the balance chamber 5 into the sealing chamber 6 to cool the mechanical seal mechanism 7. The forced convection cooling of the contact surface between the mechanical seal dynamic ring and stationary ring (temperature difference controlled less than or equal to 15°C) then flows from the sealing chamber 6 into the water cooling chamber 32 to cool the bearing body 31. Afterwards, it flows back to the working chamber of the first stage impeller 21 through the balance return water pipe 9 to complete the circulation of the cooling medium.

[0016] As a further improved specific implementation, the sealing cover 4 is provided with a central flow channel 41, which connects the balance chamber 5 and the sealing chamber 6, allowing the depressurized water in the balance chamber 5 to flow into the sealing chamber 6.

[0017] As a further improved specific implementation, the mechanical seal mechanism 7 is a single-end face cartridge mechanical seal mechanism.

[0018] As a further improved embodiment, a rolling ball bearing is installed inside the bearing housing 31. The rolling ball bearing is lubricated by lubricating oil spun up by the oil slinger driven by the rotating shaft 23. The heat generated by the rolling ball bearing during operation is cooled and dissipated by a medium (such as seawater at room temperature) flowing through the jacket outside the lubrication oil chamber of the bearing housing 31.

[0019] As a further improved embodiment, the axial force balancing mechanism 24 includes a balancing drum, a balancing sleeve, and a balancing sleeve pressure plate. The balancing drum is mounted on a rotating shaft 23 inside the discharge section housing 13. The balancing drum is surrounded by a balancing sleeve and a balancing sleeve pressure plate. There are gaps between the balancing drum and the balancing sleeve, and between the balancing drum and the balancing sleeve pressure plate, to allow balancing water to pass through.

[0020] In summary, the above are merely preferred embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A bearing housing-cooled multi-stage high-pressure centrifugal pump with a horizontal axial suction segmental design, comprising a pump housing assembly, a rotor assembly, a bearing assembly, and a sealing cover. The pump housing assembly includes a suction section housing, an intermediate section housing, and a discharge section housing connected in sequence. The rotor assembly includes a first-stage impeller, a second-stage impeller, a shaft, and an axial force balancing mechanism. Its characteristics are: A sealing cover is provided at the rear end of the discharge section shell, and a balance cavity is formed between the sealing cover and the discharge section shell. A bearing assembly is provided at the rear end of the sealing cover, and a sealing cavity is formed between the sealing cover and the bearing assembly. A mechanical seal mechanism is provided on the rotating shaft in the sealing cavity. The bearing assembly contains a bearing body and a water-cooling chamber. The balance cavity receives the balance water discharged from the axial force balance mechanism and is connected to the sealing cavity. The sealing cavity and the water-cooling chamber are connected by a connecting pipe. The water-cooling chamber is connected to the working chamber of the first-stage impeller of the suction shell by a balance return water pipe.

2. The bearing body raw water cooling multi-stage high pressure centrifugal pump according to claim 1, characterized in that: The sealing cover has a central flow channel, which connects the balance chamber and the sealing chamber.

3. The bearing body raw water cooling multi-stage high pressure centrifugal pump according to claim 1, characterized in that: The mechanical seal mechanism is a single-end face cartridge mechanical seal mechanism.

4. The bearing body raw water cooling multi-stage high pressure centrifugal pump according to claim 1, characterized in that: The bearing housing is equipped with a rolling ball bearing.

5. The bearing body raw water cooling multi-stage high pressure centrifugal pump according to claim 1, characterized in that: The axial force balancing mechanism includes a balancing drum, a balancing sleeve, and a balancing sleeve pressure plate.

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