A composite seal mechanism for a centrifugal sand pump

Abstract

The utility model relates to sand pump technical field, concretely is a kind of composite sealing mechanism of centrifugal sand pump, including pump cover, sealing box, sand pump spindle and pump shell, the lateral orifice of sealing box is equipped with water seal pipe, the rear end of sand pump spindle is inserted into pump shell, and front end is equipped with impeller, the outside of sand pump spindle is installed with mechanical seal, labyrinth seal in proper order back, the mechanical seal is by static ring, moving ring, moving ring retainer, moving ring seal sleeve, compression spring is formed, and compression spring one end is pressed on impeller, and the other end is pressed on moving ring retainer;The composite synergic effect of labyrinth seal and mechanical seal can realize the efficient stable sealing of centrifugal sand pump, effectively prolong the service life of sealing system, the composite sealing structure prevents air intrusion pump body through multiple protection mechanism, to avoid cavitation, air bondage and vibration intensification and other faults occur, ensure that equipment long-term stable operation, to further enhance the service life of sand pump key components.

Description

Technical Field

[0001] This utility model relates to the field of sand pump technology, and more specifically, to a composite sealing mechanism for a centrifugal sand pump. Background Technology

[0002] Centrifugal sand pumps are key equipment for conveying highly abrasive media such as mud, mortar, and mineral slurry. Their flow-through components (pump casing, impeller, pump cover) often have a short service life due to media erosion. Currently, the service life of flow-through components can be effectively extended by adding wear-resistant liners or using wear-resistant materials such as high-chromium cast steel and polyurethane. However, the reliability of the shaft end sealing system still seriously restricts the overall performance of the machine. When the shaft seal fails, the negative pressure formed in the rotating shaft seal area will cause air to rush into the pump chamber rapidly, resulting in a sharp drop in head and flow rate. At the same time, it will aggravate the cavitation damage of the flow-through components. The air mixing will also cause abnormal vibration of the equipment, forming a vicious cycle of "cavitation-vibration-bearing wear", which will eventually cause systemic equipment failure.

[0003] Therefore, a composite sealing structure for a centrifugal sand pump is proposed, which can prevent air from being drawn in after the seal fails, thereby stabilizing the working performance, protecting the flow components, and improving the working stability and service life of the equipment. Utility Model Content

[0004] In order to overcome the above-mentioned defects of the prior art, this utility model provides a composite sealing mechanism for a centrifugal sand pump, which solves the problem that when the shaft seal fails in the prior art, the negative pressure formed in the rotating shaft seal area will cause air to rush into the pump chamber rapidly, resulting in a sudden drop in head and flow rate, while aggravating cavitation damage to the flow-through components. The air mixing will also cause abnormal vibration of the equipment, ultimately causing equipment failure.

[0005] To solve the above technical problems, this utility model provides the following technical solution: a composite sealing mechanism for a centrifugal sand pump, including a pump cover, a sealing box, a sand pump main shaft and a pump casing. A water sealing pipe is installed in the side opening of the sealing box. The rear end of the sand pump main shaft is inserted into the pump casing and an impeller is installed at the front end. A mechanical seal and a labyrinth seal are installed sequentially on the outer side of the sand pump main shaft.

[0006] The mechanical seal consists of a stationary ring, a rotating ring, a rotating ring retainer, a rotating ring sealing sleeve, and a compression spring. One end of the compression spring presses on the impeller, and the other end presses on the rotating ring retainer. The rotating ring and the rotating ring sealing sleeve are fixedly installed inside the rotating ring retainer. Under the action of the spring force, the rotating ring and the stationary ring are in close contact to form a mechanical sealing surface. The internal channel of the water seal pipe forms a sealing cooling channel, which is directly opposite the mechanical sealing surface.

[0007] The labyrinth seal has several working end sealing teeth near the impeller end, which together with the working end sealing sleeve installed on the sealing box form several working end sealing pressure relief chambers with gaps. The labyrinth seal also has several support end sealing teeth near the support end, which together with the support end sealing sleeve installed on the support form several support end sealing pressure relief chambers with gaps.

[0008] Compared with the prior art, the beneficial effects of this utility model are:

[0009] In the above solution, the combined synergistic effect of labyrinth seal and mechanical seal can achieve efficient and stable sealing of centrifugal sand pump, effectively extending the service life of the sealing system. This composite sealing structure prevents air from entering the pump body through multiple protection mechanisms, thereby avoiding failures such as cavitation, air binding and increased vibration, ensuring long-term stable operation of the equipment, and thus improving the service life of key components of the sand pump. Attached Figure Description

[0010] Figure 1 This is a perspective view of the present utility model;

[0011] Figure 2 This is a schematic diagram of the sealing box structure of this utility model;

[0012] Figure 3 This is a schematic diagram of the labyrinth seal and mechanical seal structure of this utility model.

[0013] [Figure Labels]

[0014] 1. Pump cover; 2. Sealing box; 3. Sand pump main shaft; 4. Labyrinth seal; 5. Mechanical seal; 6. Water seal pipe; 7. Impeller; 8. Pump casing; 9. Support end sealing teeth; 10. Support end sealing sleeve; 11. Working end sealing teeth; 12. Working end sealing sleeve; 13. Stationary ring; 14. Rotating ring; 15. Rotating ring cage; 16. Rotating ring sealing sleeve; 17. Compression spring. Detailed Implementation

[0015] To make the technical problems, technical solutions and advantages of this utility model clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0016] Example 1: Please refer to Figures 1 to 3This utility model provides a technical solution: a composite sealing mechanism for a centrifugal sand pump, including a pump cover 1, a sealing box 2, a sand pump main shaft 3, and a pump casing 8. The pump cover 1, sealing box 2, and pump casing 8 are all installed on a sand pump support. A is a negative pressure zone, B is a high pressure zone, C is a support end sealing pressure reducing chamber, D is a working end sealing pressure reducing chamber, E is a sealing cooling water channel, and F is a mechanical seal surface. The plane containing the mechanical seal surface F passes through or is adjacent to the sealing cooling water channel E. After the sealing cooling water enters, it can directly act on the mechanical seal surface F. A water sealing pipe 6 is installed in the side opening of the sealing box 2. The rear end of the sand pump main shaft 3 is inserted into the pump casing 8, and an impeller 7 is installed at the front end. A mechanical seal 5 and a labyrinth seal 4 are installed sequentially on the outer side of the sand pump main shaft 3.

[0017] Mechanical seal 5 is the main seal. During normal operation, labyrinth seal 4 is the backup seal. The cooling water channel E is sealed to draw in the medium and cool mechanical seal 5. When mechanical seal surface F fails, mechanical seal 5, labyrinth seal 4, and cooling water channel E work together to block air intake and form a seal. At the same time, labyrinth seal 4 has another seal, namely the labyrinth seal 4 formed by several support end sealing pressure reducing chambers C between the sand pump support and the sand pump main shaft 3, which is used to protect the sealing ring at the bearing end cover of the sand pump support.

[0018] Example 2: Based on Example 1, in order to achieve a mechanical seal, the mechanical seal 5 is composed of a stationary ring 13, a rotating ring 14, a rotating ring retainer 15, a rotating ring sealing sleeve 16, and a compression spring 17. One end of the compression spring 17 presses on the impeller 7, and the other end presses on the rotating ring retainer 15. The rotating ring 14 and the rotating ring sealing sleeve 16 are fixedly installed inside the rotating ring retainer 15. Under the action of the spring force, the rotating ring 14 and the stationary ring 13 are in close contact to form a mechanical sealing surface. The internal channel of the water sealing pipe 6 forms a sealing cooling channel, which is directly opposite the mechanical sealing surface.

[0019] When the sand pump rotates at high speed, the medium enters from the suction port of the pump casing 8. From the center of rotation outward, the pressure gradually changes from negative pressure to positive pressure, forming a negative pressure zone A and a high pressure zone B. In the high pressure zone B, the medium is pumped out of the machine at a high linear velocity. In the negative pressure zone A, a small amount of medium is drawn in from the sealing cooling water channel E under the sealing action of the mechanical seal 5. This medium continuously acts on the mechanical seal surface F, cooling the mechanical seal 5 and maintaining the mechanical seal 5 at a lower temperature, thus extending its service life.

[0020] Example 3: Based on Example 2, in order to achieve a labyrinth seal, the labyrinth seal 4 has several working end sealing teeth 11 near the impeller 7, which together with the working end sealing sleeve 12 installed on the sealing box 2 form several working end sealing pressure relief chambers with gaps. The labyrinth seal 4 also has several support end sealing teeth 9 near the support end, which together with the support end sealing sleeve 10 installed on the support form several support end sealing pressure relief chambers with gaps.

[0021] When the mechanical seal surface F wears and fails, the negative pressure zone A tends to draw in air from the gap between the sand pump main shaft 3 and the stationary ring 13, and also tends to draw in medium from the sealed cooling channel E. Under the action of several working end sealed pressure reducing chambers D, the drawn-in air undergoes continuous heat absorption and release and pressure reduction, and finally the kinetic energy is reduced to close to zero. The more unobstructed sealed cooling channel E continuously draws in medium, which continuously acts on the mechanical seal surface F and fills the negative pressure zone A, achieving a water seal. Under the combined action of the labyrinth seal 4 and the water seal, the air is blocked from the mechanical seal 5, so that the equipment can still operate continuously and stably after the mechanical seal 5 fails, thereby improving the stable production process of the equipment.

[0022] The working process of this utility model is as follows:

[0023] When the sand pump is rotating at high speed, the medium enters from the suction port of the pump casing 8. From the center of rotation outward, the pressure gradually changes from negative pressure to positive pressure, forming a negative pressure zone A and a high pressure zone B. In the high pressure zone B, the medium is pumped out of the machine at a high linear velocity. In the negative pressure zone A, a small amount of medium is drawn in from the sealing cooling water channel E under the sealing action of the mechanical seal 5. This medium continuously acts on the mechanical seal surface F, cooling the mechanical seal 5 and maintaining the mechanical seal 5 at a lower temperature, thus extending its service life.

[0024] When the mechanical seal surface F wears and fails, the negative pressure zone A tends to draw in air from the gap between the sand pump main shaft 3 and the stationary ring 13, and also tends to draw in medium from the sealed cooling channel E. Under the action of several working end sealed pressure reducing chambers D, the drawn-in air undergoes continuous heat absorption and release and pressure reduction, and finally the kinetic energy is reduced to close to zero. The more unobstructed sealed cooling channel E continuously draws in medium, which continuously acts on the mechanical seal surface F and fills the negative pressure zone A, achieving a water seal. Under the combined action of the labyrinth seal 4 and the water seal, the air is blocked from the mechanical seal 5, so that the equipment can still operate continuously and stably after the mechanical seal 5 fails. This avoids the occurrence of serious failures such as air binding, cavitation, and increased vibration, extends the service life of the equipment and accessories, and stabilizes the production process.

[0025] Several support end sealing pressure reducing chambers C can also better protect the bearings inside the sand pump support, preventing the medium from entering the bearing cover seal ring and accelerating the damage of the seal ring when the medium leaks.

[0026] Finally, the following points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can be mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change.

[0027] Secondly: The accompanying drawings of the embodiments disclosed in this utility model only involve the structures involved in the embodiments disclosed in this utility model. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this utility model can be combined with each other.

[0028] Finally: 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, improvements, etc., 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 composite sealing mechanism for a centrifugal sand pump, characterized in that, The pump includes a pump cover (1), a sealing box (2), a sand pump main shaft (3) and a pump casing (8). A water sealing pipe (6) is installed in the side opening of the sealing box (2). The rear end of the sand pump main shaft (3) is inserted into the pump casing (8) and an impeller (7) is installed at the front end. A mechanical seal (5) and a labyrinth seal (4) are installed sequentially on the outer side of the sand pump main shaft (3). The mechanical seal (5) consists of a stationary ring (13), a rotating ring (14), a rotating ring retainer (15), a rotating ring sealing sleeve (16), and a compression spring (17). One end of the compression spring (17) is pressed on the impeller (7), and the other end is pressed on the rotating ring retainer (15). The rotating ring (14) and the rotating ring sealing sleeve (16) are fixedly installed inside the rotating ring retainer (15). Under the action of the spring force, the rotating ring (14) and the stationary ring (13) are in close contact to form a mechanical sealing surface. The internal channel of the water sealing pipe (6) forms a sealing cooling channel, which is directly opposite the mechanical sealing surface. The labyrinth seal (4) has several working end sealing teeth (11) near the impeller (7), which together with the working end sealing sleeve (12) installed on the sealing box (2) form several working end sealing pressure relief chambers with gaps. The labyrinth seal (4) has several support end sealing teeth (9) near the support end, which together with the support end sealing sleeve (10) installed on the support form several support end sealing pressure relief chambers with gaps.

Images