A petrochemical process pump

Abstract

The present invention discloses a two-stage horizontal petrochemical process pump, comprising a suction chamber, a transition section, a pressure chamber, a pump body, a pump cover, a shaft, an impeller, a mechanical seal, a balancing hole, a bearing assembly, an oil slinger, a coupling, an interstage sleeve, a bearing and its bracket, and a sealing assembly. The first-stage impeller adopts a double-suction design, while the secondary impeller adopts a single-suction design. Both impellers are open, meeting the pump head and flow requirements of different users. The suction chamber is a semi-spiral suction chamber, and the pressure chamber is a spiral double-volute single-outlet pressure chamber. The pump cover and pump body differ from those of most commercially available pumps due to their structural uniqueness, designed for transporting high-temperature, high-pressure liquids. The mechanical seal utilizes a single-end balanced seal. In addition to certain structural advantages, the present invention can also balance radial forces acting on the impeller under various operating conditions. The present invention features a top-inlet and top-outlet design, compact components, good sealing performance, excellent performance, safety and reliability, good cavitation resistance, and a wide range of applications.

Description

Technical Field

[0001] The present invention relates to the technical field of energy chemical industry, in particular to a petrochemical process pump. Background Art

[0002] The petrochemical process pump described in this invention has widespread application across various industrial product sectors, capable of transporting both high- and low-temperature petrochemical liquids. Consequently, higher performance and various performance indicators are required. Due to varying needs and operating conditions, the petrochemical pump disclosed in Patent No. ZL 20092007218.1, for example, utilizes a single-stage, single-suction structure, which may not meet user flow and head requirements. To overcome the shortcomings of the prior art, a two-stage petrochemical process pump is urgently needed to address these issues. Summary of the Invention

[0003] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a petrochemical process pump.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A petrochemical process pump, the parameters of the pump are: horizontal two-stage petrochemical process pump, and the flow rate can reach Q=280m 3 / h, and can transport fluid media such as oil and water, and the operating temperature range is T = -45℃ ~ 430℃, the pump is cast as a whole, and the impeller and shaft are cast steel, and the coupling material is Q235 steel, the pump body adopts a horizontal structure, the suction chamber and the water pressure chamber are upper inlet and upper outlet respectively, the motor drive mode is direct connection, the two impellers are double suction and single suction (seen from the inlet), and both adopt open impellers, the suction chamber is a semi-spiral suction chamber, and the water pressure chamber is a spiral double-volute single-outlet water pressure chamber, the first-stage impeller to the secondary impeller is designed as a double-volute double-outlet transition channel, and the transition channel can efficiently transport fluid.

[0006] Furthermore, the mechanical seal fixes the pump cover and the bearing bracket and adopts a single end face balanced seal

[0007] Furthermore, the suction chamber inlet and the pressurized water outlet are standard flanges, and the cross-sections are fixed with screws and nuts.

[0008] Furthermore, the pump shaft as a whole uses 6 standard keys of different sizes, which are respectively fixed to the bearing end face, secondary impeller, interstage sleeve, first-stage impeller, bushing, and coupling, and the coupling uses a single round head ordinary flat key.

[0009] Furthermore, the bearing bracket and the pump cover are fixed with screws and nuts.

[0010] Furthermore, the balancing hole drilled in the impeller rear cover plate is in communication with the mouth ring.

[0011] Furthermore, the pump cover and the pump body are sealed with a metal wound gasket and fixed with a screw and a nut.

[0012] Furthermore, the bearing bracket and the pump cover are sealed with a sealing ring, and the bearing retaining ring and the shaft end retaining ring are distributed on the pump shaft at both ends of the bearing.

[0013] The beneficial effects of the present invention are:

[0014] 1. The two-stage horizontal structure improves the single-stage single-suction structure of conventional chemical process pumps. The two-stage impeller increases the pump head, making the impeller less susceptible to cavitation and balancing the axial force brought by the first-stage impeller.

[0015] 2. By designing the suction chamber into a semi-spiral shape, the flow capacity is improved, the inflow of fluid is made smoother and more stable, and the first-stage impeller of the pump is not easily cavitated.

[0016] 3. By designing the transition flow channel into a double-volute double-outlet type, the radial force caused by the fluid entering the transition flow channel can be more effectively balanced.

[0017] 4. The inlet fluid is introduced into the secondary impeller rear cover through the balance hole, which balances the axial force caused by the rotation of the secondary single-suction impeller and makes its structure compact and complete.

[0018] 5. The use of double volute and double outlet water pressure chamber can make the flow channel outlet smoother and reduce local head loss; on the other hand, it can balance the radial force brought by the impeller and reduce the impact of water on the volute. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a front cross-sectional view of a petrochemical process pump proposed by the present invention;

[0020] Figure 2 This is a right side view of a petrochemical process pump proposed by the present invention (without the coupling).

[0021] Figure numerals: 1. bearing body component A, 2. pipe plug, 3. mechanical seal component A, 4. rear pump cover, 5. secondary impeller, 6. water pressure chamber, 7. interstage sleeve, 8. pump body mouth ring, 9. suction chamber, 10. pump cover bushing, 11. front pump cover, 12. mechanical seal component B, 13. bearing bracket, 14. oil filling port, 15. bearing body component B, 16. coupling, 17. oil slinger, 18. pump shaft, 19. first-stage impeller, 20. pump body, 21. shaft sleeve, 22. cooling chamber, 23. bearing, 24. shaft end retaining ring. DETAILED DESCRIPTION

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments. Obviously, the embodiments described are only a part of the present invention, rather than all of the embodiments.

[0023] Reference Figure 1 The pump shaft is connected from the center to both ends in sequence to the first-stage impeller (19), interstage sleeve (7), pump body (20), pump body mouth ring (8), pump cover (4) (11), mechanical seal device (3) (12), bearing components, bearing (23), oil slinger (17), shaft end retaining ring (24) and coupling (16) motor. The motor is directly driven and the coaxiality of the motor shaft and pump shaft connection needs to be checked regularly. The fluid flows in through the semi-spiral suction chamber (9), passes through the first-stage double-suction impeller, and then flows into the next stage through the transition flow channel. The next stage is a single-suction impeller. The outflowing fluid enters the pipeline through the water pressure chamber. When assembling the rotor components, attention should be paid to the relative position of the rotor components and the pump body.

[0024] In the present invention, the pump cover (4) (11) needs to adopt a mechanical seal (3) (12) to prevent liquid leakage and corrosion of other parts, and the sealing method is a static seal to prevent the sealing leakage problem caused by vibration. If there is liquid in the pump in cold areas in winter, the excess liquid can be discharged through the pipe plug (2) to prevent ice from breaking the pump body. The impeller (5) (19) is radially positioned with the pump body (20) and the pump cover (4) (11) through the mouth ring (8). Petrochemical pumps are often used to transport high-temperature or low-temperature liquids, which puts higher requirements on the connection between the pump shaft (18) and the motor. The support method will also become a central support, and the pump as a whole will be suspended to prevent the pump shaft (18) and the motor shaft from being on the same axis due to thermal expansion and contraction. This support method can greatly improve such problems.

[0025] Lubrication method: oil lubrication, oil is injected through the oil filling port (14), and the oil slinger ring throws the oil to the bearing (23).

[0026] Cooling method: Circulating water is injected into both ends of the pump and the bottom plate, and the pump is cooled through the cooling cavity (22) in the pump cover (4) (11), thereby reducing the influence of high temperature and low temperature on the pump and reducing its operating performance.

[0027] Installation method: Since this pump is a horizontal structure, the whole is installed in sequence from the center to the two ends. First, install the pump shaft (18) and its mouth ring (8) on the pump body (20), then install the interstage sleeve (7) and its two impellers (19) and (5), and then install the bushing (10) and the pump covers (4) and (11) at both ends. Then install the mechanical seals (3) and (12), bearings (23), oil slinger (17) and their corresponding parts at both ends, and finally install the shaft end retaining ring (24) and the coupling (16) motor. Dismantling and maintenance are carried out in the opposite way, which is convenient and easy.

[0028] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A petrochemical process pump, comprising a chemical pump body, characterized in that: The pump as a whole adopts a two-stage horizontal structure to increase the pump head. The first-stage impeller (19) adopts a double-suction structure, and the secondary impeller (5) adopts a single-suction structure, and both adopt open impellers. The openings of the suction chamber (9) and the water pressure chamber (6) are both upward, and the suction chamber (9) of the pump is a semi-spiral suction chamber; The water pressure chamber (6) at the fluid outlet is designed as a spiral double-volute single-outlet type; The fluid is transported from the first-stage impeller (19) to the secondary impeller (5) through a double-volute double-outlet transition channel; The connection between the pump shaft (18) and the motor is affected by the thermal expansion and contraction of the fluid, and the support method is centerline support, and the pump body (20) is suspended support; The cooling chamber (22) at both ends of the pump needs to be filled with water for cooling, and the bottom plate also needs to be filled with water for cooling; Inject oil from the oil filling port (14) into the oil slinger (17) mounted on both ends of the pump shaft to lubricate the angular contact ball bearings (23); The balancing hole is used to introduce fluid from the suction chamber (9) into the rear cover of the secondary impeller (5) to balance the axial force; A pump body mouth ring (8) is provided between the first-stage impeller (19), the secondary impeller (5), the pump body (20), the front pump cover (11) and the rear pump cover (4) for positioning, and an interstage sleeve (7) is provided between the first-stage impeller (19) and the secondary impeller (5) for axial positioning; A metal wound gasket is provided between the pump body (20) and the front pump cover (11) and the rear pump cover (4) to enhance sealing performance; The front pump cover (11) and the bearing bracket (13) are connected by a mechanical sealing component B (12); The petrochemical process pump is installed in the following order from the center to the two ends: a pump shaft (18), a first-stage impeller (19), an interstage sleeve (7), a secondary impeller (5), a pump body mouth ring (8), a front pump cover (11), a rear pump cover (4), a mechanical seal component A (3), a mechanical seal component B (12), a bearing (23), an oil slinger (17), a shaft end retaining ring (24), and a coupling (16).

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