Circulating pump shaft sealing structure of heat pump salt manufacturing evaporation tank

Abstract

The utility model discloses a shaft sealing structure of a circulating pump of a heat pump salt-making evaporation tank, which belongs to the technical field of pump shaft sealing in a heat pump salt-making process and comprises a shaft and a shaft sleeve sleeved on the shaft, an impeller is mounted at one end of the shaft, a bearing box is arranged at the other end of the shaft, and a sealing compression ring is arranged at one end of the shaft sleeve close to the impeller. The sealing pressing ring is connected with the end of the shaft sleeve, an annular sealing groove is formed between the sealing pressing ring and the end face of the shaft sleeve, and a rubber O-shaped ring is assembled in the annular sealing groove. According to the modular design of the structure, the sealing pressing ring and the sealing ring are more convenient to mount and dismount, later maintenance and replacement are facilitated, and the maintenance cost and the downtime are reduced. On the whole, the sealing structure not only improves the running safety and reliability of the pump shaft, but also prolongs the service life of the equipment, and improves the running stability and production efficiency of the heat pump salt manufacturing core equipment, namely the evaporation tank circulating pump.

Description

Technical Field

[0001] This utility model belongs to the field of pump shaft sealing technology for heat pump salt production processes, and particularly relates to a circulating pump shaft sealing structure for a heat pump salt production evaporator. Background Technology

[0002] The circulating pump in the heat pump salt production evaporator is a key piece of equipment used in the evaporation and crystallization system during the heat pump salt production process. Its main function is to promote the circulation of the feed liquid in the evaporator, which consists of a heating chamber, a circulation pipe, and an evaporation chamber, thereby enhancing the heat transfer effect, improving the evaporation efficiency, and thus increasing the evaporation of brine moisture, the concentration of the feed liquid, and the growth rate of sodium chloride crystals.

[0003] Currently, the circulating pump in the heat pump salt production evaporator has several shortcomings in terms of structural design and sealing protection. Firstly, an impeller is installed at one end of the circulating pump shaft, with both the shaft and impeller extending into the pump casing filled with brine. The other end of the circulating pump shaft is connected to a bearing housing, both located outside the pump casing. Driven by the impeller, the supersaturated brine containing a large amount of salt particles flows rapidly within the pump casing. To prevent the highly corrosive, high-temperature brine inside the pump casing from overflowing due to the pressure difference between the inside and outside of the casing, a packing seal is used between the outer side of the shaft sleeve and the stuffing box of the pump casing. A combination of clearance seal and O-ring seal is used between the inner side of the shaft sleeve and the pump shaft. This means that a small gap is maintained between most of the inner area of ​​the shaft sleeve and the pump shaft, relying on the viscous resistance of the high-concentration brine to prevent leakage. Simultaneously, a groove is provided on the top of the shaft sleeve near the bearing housing end of the circulating pump shaft. The O-ring installed in the groove deforms under pressure and fills the gap at the contact surface, thus forming an O-ring seal. This combined sealing scheme inherently carries the risk of seal failure, and this risk increases with operating time for the following reasons: The gap sealing method is designed to allow for minor leakage, making zero leakage impossible. Although both the shaft and bushing are protected against corrosion, repeated disassembly and assembly during maintenance leads to increased localized wear and gaps, causing leakage to exceed limits and triggering seal failure in this area. This can easily accelerate brine erosion, causing localized corrosion, pitting, stress corrosion cracking, and other serious consequences, shortening the shaft's service life. Furthermore, the existing pump shaft uses an O-ring seal at the bushing end near the bearing housing. The O-ring, installed in the bushing groove, deforms under pressure to fill the gap in the contact surface, forming a seal. The bushing end with the O-ring is far from the shaft head, making installation difficult. During shaft and bushing assembly, the seal is easily deformed, displaced, or even damaged by axial compressive forces, leading to seal failure that is difficult to detect during assembly. Once the seal fails, brine will not only seep into the space between the shaft and the bushing, continuously corroding the shaft, but also increase the corrosion of the sealing surface, leading to a larger gap and a surge in leakage, creating a vicious cycle until the seal completely fails. This results in severe leakage of the pump's contents, affecting the stable operation of the circulating pump. To avoid these problems, companies often need to periodically shut down the pump for inspection, maintenance, and even replacement of key components. This not only increases maintenance costs and manpower but also negatively impacts continuous production, reducing overall operating efficiency and equipment reliability. Utility Model Content

[0004] In response to the problems of unreasonable shaft sleeve sealing structure, easy seal failure leading to brine erosion of the shaft, causing pump shaft corrosion, brine leakage from the pump and corrosive damage to the pump body and auxiliary mechanisms, resulting in frequent maintenance of the circulating pump and serious impact on production operation, this utility model provides a shaft sealing structure for circulating pumps in heat pump salt production evaporators.

[0005] This utility model is implemented as follows: a shaft sealing structure for a circulating pump in a heat pump salt production evaporator includes a shaft and a bushing fitted on the shaft. An impeller is installed at one end of the shaft. The characteristic feature is that a sealing pressure ring is provided at the end of the bushing near the impeller. The sealing pressure ring is connected to the end of the bushing, and an annular sealing groove is formed between the sealing pressure ring and the end face of the bushing along the shaft surface. A rubber O-ring is fitted in the annular sealing groove.

[0006] In the above technical solution, preferably, the ends of the sealing ring and the bushing are connected by screws that are evenly arranged in a circumferential direction.

[0007] In the above technical solution, preferably, the inner side of the annular end face of the sealing ring opposite to the bushing is provided with opposing circumferential recesses, and the annular sealing groove is formed between the two circumferential recesses. The inner side of the annular end face of the sealing ring opposite to the bushing near the axis is provided with opposing circumferential recesses, and the two circumferential recesses together form the annular sealing groove with a rectangular cross-section.

[0008] In the above technical solution, preferably, the sealing ring is provided with a countersunk hole, and the screw is fitted into the countersunk hole.

[0009] In the above technical solution, preferably, the countersunk hole of the sealing ring is provided with a sealing layer located outside the screw.

[0010] In the above technical solution, preferably, an outer sealing ring is provided between the opposite annular end faces of the sealing pressure ring and the bushing, and the outer sealing ring forms an circumferential seal located around the screw.

[0011] In the above technical solution, preferably, the sealing pressure ring and the bushing have opposite annular end faces with circumferential sealing grooves that are close to the outer side, and the outer sealing ring is installed in the circumferential sealing groove.

[0012] The heat pump salt production evaporator circulating pump shaft sealing structure proposed in this utility model is an optimized design based on the traditional sealing structure, and has the following advantages and technical effects:

[0013] First, while maintaining the original combination sealing scheme of gap sealing between the inner side of the shaft sleeve and the pump shaft supplemented by O-ring sealing, a sealing pressure ring is added at the end of the shaft near the impeller. The sealing pressure ring cooperates with the shaft sleeve and is an independent post-installation component. This structural design makes the installation process of the annular seal ring independent from the assembly process of the shaft and shaft sleeve. Instead, the sealing pressure ring and seal ring are installed after the shaft and shaft sleeve are assembled. This effectively avoids the problem of seal ring failure caused by compression, shearing or deformation during shaft sleeve assembly in traditional structures.

[0014] Secondly, by forming a closed annular sealing groove together with the sealing ring and the bushing, the precise installation position and uniform force of the sealing ring are ensured, greatly improving the positioning stability and sealing reliability of the sealing ring. This not only reduces the risk of seal failure due to misalignment or detachment of the sealing ring, but also enhances the controllability and ease of operation of the overall assembly.

[0015] Furthermore, the optimized sealing structure forms an effective sealing barrier near the impeller end, significantly enhancing the sealing performance between the shaft and the bushing. This prevents brine from seeping into the bushing through the sealing gap, avoiding corrosion of the shaft. It also blocks the channel for brine to leak out of the pump casing, reducing the risk of damage to the pump body and auxiliary facilities caused by leaked brine from the source.

[0016] Furthermore, the modular design of this structure makes the installation and disassembly of the sealing ring and sealing ring more convenient, which is beneficial for later maintenance and replacement, reducing maintenance costs and downtime. Overall, this sealing structure not only improves the safety and reliability of pump shaft operation, but also extends the service life of the evaporator circulating pump and its auxiliary facilities, and improves the operational stability and production efficiency of the heat pump salt production evaporation crystallization system. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 yes Figure 1 Enlarged view of part A. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this utility model.

[0020] To address the problems of unreasonable shaft sleeve sealing structures in existing evaporator circulating pumps, which lead to seal failure, brine erosion of the shaft, pump shaft corrosion, brine leakage, and corrosive damage to the pump body and auxiliary mechanisms, resulting in frequent pump maintenance and significant disruption to production, this invention provides a shaft sealing structure for a heat pump salt production evaporator circulating pump. To further illustrate the structure of this invention, a detailed description is provided below in conjunction with the accompanying drawings:

[0021] Please see Figure 1 and Figure 2 A shaft sealing structure for a circulating pump in a heat pump salt production evaporator includes a shaft 1 and a bushing 2 fitted on the shaft, with an impeller installed at one end of the shaft.

[0022] A sealing ring 3 is added to one end of the bushing near the impeller. The sealing ring is connected to the end of the bushing. Furthermore, the sealing ring and the end of the bushing are connected by screws 4 arranged circumferentially. To further improve assembly accuracy and sealing reliability, the inner diameter of the sealing ring and the outer diameter of the shaft are fitted with a clearance fit or a transition fit, allowing the sealing ring to be easily fitted onto the shaft without affecting its rotation, and achieving a secure connection with the end of the bushing using fasteners. The screws are preferably made of a corrosion-resistant alloy material. The sealing ring can be connected circumferentially using four or six symmetrically arranged screws to ensure balanced force and structural stability after installation, avoiding seal failure or structural deformation due to uneven screw force.

[0023] The sealing ring has a countersunk hole, into which the screw is fitted. A sealing layer 5 is located outside the screw within the countersunk hole of the sealing ring. The exposed portion of the screw is isolated from the external environment by the sealing layer, preventing brine from seeping into the screw connection gap, thereby further improving the overall sealing performance and structural stability of the sealing ring. The sealing layer can be made of fluororubber, which is resistant to high temperatures (generally up to 200℃), brine, most inorganic salts and inorganic acids, and has good elasticity, making it suitable for use as a compression sealing layer. It is molded into a sealing washer, ring-shaped gasket, or coated gasket, and then glued or assembled into the countersunk hole. The countersunk hole of the sealing ring is a pre-machined tapered countersunk hole with a taper angle of 82°. The screw shank is fully threaded, and the tapered countersunk screw matches the countersunk hole. After installation, the head is 0.1-0.3mm below the end face of the sealing ring, and the screw's taper angle is 82°.

[0024] An annular sealing groove 6 is formed between the end faces of the sealing ring and the bushing, and an annular sealing ring 7 is fitted into the annular sealing groove. Specifically, the inner sides of the annular end faces of the sealing ring and the bushing opposite each other are provided with opposing circumferential recesses, and an annular sealing groove is formed between the two circumferential recesses. The circumferential recesses can adopt wedge-shaped, arc-shaped, or trapezoidal cross-sections, and the depth and width of the grooves match the cross-sectional dimensions of the selected sealing ring, so that the sealing ring is in a state of moderate compression in both radial and axial directions after installation, which can ensure effective sealing while avoiding damage or extrusion of the sealing ring due to excessive compression. The edges of the circumferential recesses can be designed with guide rounds or chamfer transition structures to avoid edge cutting or shearing damage during the sealing ring compression process, thereby improving the service life of the sealing ring.

[0025] An outer sealing ring 8 is provided between the opposing annular end faces of the sealing ring and the bushing, forming a circumferential seal around the screw. The opposing annular end faces of the sealing ring and the bushing have opposing circumferential sealing grooves located close to the outer side, and the outer sealing ring is installed in these grooves. The outer sealing ring serves to block the seepage path around the screw, preventing corrosion and forming a second sealing barrier to prevent brine from seeping into the sealing cavity or reduction mechanism along the axial direction or through the screw hole.

[0026] The annular seal is preferably made of highly elastic and corrosion-resistant materials such as fluororubber (FKM), ethylene propylene diene monomer (EPDM) rubber, or polytetrafluoroethylene (PTFE), which have good chemical stability, anti-aging properties and sealing elasticity, and are suitable for high temperature, high salt and highly corrosive environments.

[0027] Regarding the installation method, the structure adopts a post-installation design. First, the shaft and shaft sleeve are assembled, then the sealing ring is placed in the annular sealing groove at the end of the shaft sleeve, and finally the sealing pressure ring is fixed to the end of the shaft sleeve with screws. This achieves non-interference assembly of the sealing ring, effectively avoiding the shearing, squeezing, deformation, or even misalignment problems of the sealing ring during the process of the shaft sleeve sliding into the shaft in the traditional solution, and significantly improving the controllability of the assembly process and the consistency of the sealing structure.

[0028] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A shaft sealing structure for a circulating pump in a heat pump salt production evaporator, comprising a shaft and a bushing fitted onto the shaft, an impeller mounted at one end of the shaft, and a bearing housing at the other end of the shaft, characterized in that: A sealing ring is provided at one end of the bushing near the impeller. The sealing ring is connected to the end of the bushing, and an annular sealing groove is formed between the sealing ring and the end face of the bushing. A rubber O-ring is fitted in the annular sealing groove.

2. The heat pump salt-making evaporator circulating pump shaft sealing structure according to claim 1, characterized in that: The sealing ring and the end of the bushing are connected by screws that are evenly spaced in a circumferential direction.

3. The heat pump salt-making evaporator circulating pump shaft sealing structure according to claim 2, characterized in that: The sealing ring has opposing circumferential recesses on the inner side of its annular end face near the shaft, and the two circumferential recesses together form the annular sealing groove.

4. The heat pump salt-making evaporator circulating pump shaft sealing structure according to claim 3, characterized in that: The sealing ring is provided with a countersunk hole, and the screw is fitted into the countersunk hole.

5. The heat pump salt-making evaporator circulating pump shaft sealing structure according to claim 4, characterized in that: The countersunk hole of the sealing ring is provided with a sealing layer located outside the screw.

6. The heat pump salt-making evaporator circulating pump shaft sealing structure according to claim 5, characterized in that: An outer sealing ring is provided between the sealing pressure ring and the opposite annular end face of the bushing, and the outer sealing ring forms a circumferential seal located around the screw.

7. The heat pump salt-making evaporator circulating pump shaft sealing structure according to claim 6, characterized in that: The sealing ring and the bushing have opposing annular end faces with circumferential sealing grooves that are close to the outer side, and the outer sealing ring is installed in the circumferential sealing groove.

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