A packing seal structure for vertical high-temperature molten salt pumps

Abstract

This invention relates to a packing seal structure for a vertical high-temperature molten salt pump. The sealing structure includes: a shaft, a retaining ring, a packing sleeve, a stuffing box, copper packing, a segmented porous packing ring, a key, a segmented packing gland, a liquid position sensor, and a temperature sensor. The copper packing and the segmented porous packing ring are arranged inside the stuffing box and are pressed tightly by the segmented packing gland. The packing sleeve is fixed to the shaft by the key and the retaining ring and rotates with the shaft. The copper packing is in direct contact with the packing sleeve. The gland fixing bolt assembly fixes the packing gland and provides the clamping force. The liquid position sensor and temperature sensor are respectively installed on the segmented packing gland and the stuffing box. This invention solves the problems of easy seizing and damage to the threads of the high-temperature molten salt pump packing seal; the difficulty in disassembling the packing gland and packing ring; and the problem of automatic monitoring of the operational health of the copper packing, thus achieving the goal of reducing equipment maintenance time and lowering maintenance costs.

Description

Technical Field

[0001] This invention relates to a packing seal structure, specifically to a packing seal structure that solves the problems of easy seizing and damage of the packing seal threads in high-temperature molten salt pumps, the difficulty in disassembling the packing gland and packing ring, and the problem of automatic monitoring of the operational health of copper packing for vertical high-temperature molten salt pumps. Background Technology

[0002] Molten salt pumps are specifically designed for transporting high-temperature binary or ternary molten salts. They are used for transporting high-temperature nitrates and nitrites, and are also widely used in chemical processes such as melamine production, salt production, alkali production, and urea production. The temperature of the transported medium is typically between 300℃ and 600℃. This device is an important component in solar thermal power generation and molten salt energy storage.

[0003] Molten salt pumps, as the main equipment for transporting and storing heat transfer media in solar power systems, require constant adjustment of operating conditions according to system requirements. They are characterized by a wide operating range and frequent start-stop cycles. The packing seal of the molten salt pump is a crucial component preventing leakage of high-temperature molten salt from the pump. In actual operation, the temperature at the packing seal remains between 120℃ and 220℃. Due to alternating thermal stress, the threaded structure is prone to seizing. Copper packing requires frequent inspection and replacement due to wear. Conventional packing seal structures suffer from several drawbacks: the need for periodic disassembly of the packing gland to check for replacement, the risk of thread seizing and breakage during disassembly due to the large number of parts removed, personnel safety issues caused by high-temperature components, and high costs associated with long disassembly and inspection cycles. Summary of the Invention

[0004] To address the aforementioned problems, the main objective of this invention is to provide a solution that resolves the issues of easy seizing and damage to the packing seal threads of high-temperature molten salt pumps, difficulty in disassembling the packing gland and packing ring, and the problem of automatic monitoring of the operational health of copper packing for packing seal structures in vertical high-temperature molten salt pumps.

[0005] The present invention solves the above-mentioned technical problems through the following technical solution: a packing seal structure for a vertical high-temperature molten salt pump, the packing seal structure for a vertical high-temperature molten salt pump comprising: a shaft, a retaining ring, a packing bushing, a stuffing box, copper packing, a segmented porous packing ring, a key, a segmented packing gland, a liquid position sensor, and a temperature sensor; the copper packing and the segmented porous packing ring are arranged in the stuffing box and are pressed tightly by the segmented packing gland; the packing bushing is fixed to the shaft by the key and the retaining ring and rotates with the shaft; the copper packing is in direct contact with the packing bushing, and the gland fixing bolt assembly fixes the packing gland and provides the packing gland with clamping force; the liquid position sensor and the temperature sensor are respectively installed on the segmented packing gland and the stuffing box.

[0006] In a specific embodiment of the present invention, the gland fixing bolt assembly includes a union bolt, a pin, a cotter pin, a heat insulation sleeve, and a nut. The pin is connected to the stuffing box, and the cotter pin fixes the pin. The union bolt is installed on the pin and is fixedly connected to the split stuffing gland through the heat insulation sleeve and the nut.

[0007] In a specific embodiment of the present invention, the copper packing directly contacts the packing bushing to prevent leakage of the internal high-temperature molten salt. When the packing bushing rotates with the shaft, it generates a large amount of heat through relative friction with the stationary copper packing. This heat is carried away by the low-temperature compressed air introduced into the segmented porous packing ring from the outside.

[0008] In a specific embodiment of the present invention, the segmented porous packing ring is installed inside the stuffing box and adopts a segmented design. The outer ring of the segmented porous packing ring is tightly fitted with the stuffing box, and a gap is left between the inner ring of the segmented porous packing ring and the shaft.

[0009] In a specific embodiment of the present invention, copper packing is installed inside a stuffing box, the copper packing is located between the shaft and the stuffing box and is in contact with the shaft and the stuffing box, and the openings of the copper packing are arranged alternately.

[0010] In a specific embodiment of the present invention, one end of the split packing gland is inserted into the stuffing box, and the other end is connected and fixed to the stuffing box through the gland fixing bolt assembly.

[0011] In a specific embodiment of the present invention, the packing bushing is provided with an annular groove, and the segmented packing gland is provided with a liquid collection groove. The annular groove and the liquid collection groove cooperate with each other to collect leaked molten salt.

[0012] In a specific embodiment of the present invention, the heat insulation sleeve is a heat insulation sleeve with a porous surface.

[0013] The positive and progressive effects of this invention are as follows: The packing seal structure for vertical high-temperature molten salt pumps provided by this invention has the following advantages: The present invention features a segmented porous packing ring with a disassembly threaded hole on the upper part of the packing ring. Compared with conventional full-circle packing rings, this invention solves the problems of difficulty in removing it from the stuffing box and difficulty in removing it from the shaft for replacement.

[0014] The present invention provides a segmented packing gland with a threadless segmented structure, which eliminates the threaded connection compared with conventional segmented packing glands, and solves the problem that conventional segmented structures are difficult to disassemble under high-temperature conditions due to the fixed thread engagement.

[0015] The packing gland fixing bolt of this invention adopts a pin shaft plus heat insulation pad design, which significantly reduces the temperature at the threaded connection compared with the conventional single bolt structure and solves the problem of bolt seizure and breakage.

[0016] This invention designs a device for automatically monitoring the operational health of copper packing, solving the problem of the need for regular disassembly and inspection of copper packing and reducing operating costs.

[0017] In this invention, the packing bushing is provided with an annular groove, and the split packing gland is provided with a liquid collection groove. The two work together to collect the leaked molten salt. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0019] Figure 2 for Figure 1 A magnified view of a portion of point A in the middle.

[0020] Figure 3 for Figure 1 An explosion diagram.

[0021] Figure 4 This is a schematic diagram of a segmented packing gland structure.

[0022] Figure 5 This is a schematic diagram of the split-type packing gland.

[0023] The following are the names corresponding to the reference numerals in this invention: Figure 1-5 In the middle: 1. Shaft 2. Snap ring 3. Packing sleeve 4. Stuffing box 5. Copper packing 6. Split porous packing ring 7. Key 8. Nut 9. Heat insulation sleeve 10. Split packing gland 11. Union bolt 12. Pin 13. Cotter pin 14. Liquid position sensor 15. Temperature sensor Detailed Implementation

[0024] The preferred embodiments of the present invention are given below with reference to the accompanying drawings to illustrate the technical solution of the present invention in detail.

[0025] Figure 1 This is a schematic diagram of the overall structure of the present invention. Figure 2 for Figure 1 A magnified view of a portion of point A in the middle. Figure 3 for Figure 1 An explosion diagram, such as Figure 1-3 As shown: The present invention proposes a packing seal structure for a vertical high-temperature molten salt pump. The structure includes a shaft 1, a retaining ring 2, a packing bushing 3, a stuffing box 4, copper packing 5, a segmented porous packing ring 6, a key 7, a nut 8, a heat insulation sleeve 9, a segmented packing gland 10, a union bolt 11, a pin 12, a cotter pin 13, a liquid position sensor 14, and a temperature sensor 15.

[0026] In this invention, the copper packing 5 and the segmented porous packing ring 6 are arranged inside the stuffing box 4 and pressed together by the segmented packing gland 10. The outer ring of the segmented porous packing ring 6 fits tightly with the stuffing box 4, while a gap is left between the inner ring of the segmented porous packing ring 6 and the shaft 1.

[0027] The packing sleeve 3 is fixed to the shaft 1 by a key 7 and a retaining ring 2, and rotates with the shaft. The copper packing 5 is in direct contact with the packing sleeve 3 to prevent leakage of the internal high-temperature molten salt. When the packing sleeve 3 rotates with the shaft 1, it generates a large amount of heat due to relative friction with the stationary copper packing 5. This heat is carried away by the low-temperature compressed air introduced into the segmented porous packing ring 6 from the outside, keeping the copper packing 5 operating at an appropriate temperature. In this invention, the segmented porous packing ring 6 adopts a design with radial split in the middle and threaded removal holes on the upper end face. After the segmented porous packing ring is removed from the stuffing box 4, it can be directly removed from the shaft without removing other parts on the pump shaft, which greatly reduces maintenance time and cost compared with conventional full-circle packing rings.

[0028] In this invention, one end of the split packing gland 10 is inserted into the cavity of the packing gland 4 to press the copper packing 5, and the other end is fixed to the packing gland 4 by a live bolt 11 passing through a U-shaped hole, a nut 8, and a heat insulation sleeve 9.

[0029] In the specific implementation process, the copper packing 5 is installed in the stuffing box 4. The copper packing 5 is located between the shaft and the stuffing box 4 and is in contact with the shaft and the stuffing box 4. The openings of the copper packing 5 are arranged in an alternating manner.

[0030] like Figure 3-4 As shown: The split packing gland 10 adopts a boltless fixing structure. The split packing gland 10 is split radially in the middle, and the fixing ears on both sides are axially split, dividing the split packing gland 10 into two parts. When the split packing gland 10 is installed into the stuffing box 4, the cavity of the stuffing box 4 provides radial positioning, and the fixing ears on both sides of the axial split provide axial positioning, so that the packing gland is formed as a whole, pressing the copper packing 5. The fixing bolts of the split structure are eliminated, and the problem of easy seizing of the original threads is eliminated.

[0031] In this invention, the union bolt 11 is fixed to the fixing lug of the stuffing box 4 via a pin 12 and a cotter pin 13, without directly contacting the stuffing box 4. The perforated structure reduces direct heat transfer while enhancing heat dissipation at the bolt, thus lowering the thread temperature. A porous heat-insulating sleeve 9 is added between the union bolt 11 and the split-type stuffing cap 10, reducing the heat transferred from the split-type stuffing cap 10 to the threaded area. This design significantly reduces the temperature at the threaded area, solving the problem of thread seizing due to high temperatures.

[0032] In this invention, the packing sleeve 3 is provided with an annular groove 301, and the segmented packing gland 10 is provided with a liquid collection tank 1001. These two work together to collect leaked molten salt. A liquid position sensor 14 is installed on the segmented packing gland 10 to monitor whether there is molten salt medium in the liquid collection tank of the segmented packing gland 10. A temperature sensor 15 is installed on the stuffing box 4 to monitor the operating temperature of the copper packing 5. The sensors send the data to the control system in real time. The control system judges the health of the equipment operation by the operating temperature of the copper packing 5 and the medium condition in the segmented packing gland 10. The control system automatically performs alarm processing based on the operating temperature and whether there is a medium leak, so as to achieve the purpose of automatic monitoring and early warning.

[0033] Temperature sensor 15 monitors the operating temperature of the copper packing and sends a temperature signal to the control system. When the temperature exceeds a certain value (230℃), the system will start an alarm to remind maintenance personnel to check the copper packing.

[0034] When the equipment is running, the packing sleeve 3 rotates together with the shaft. When there is molten salt leakage in the copper packing part, the leaked molten salt will leak to the outside through the gap between the packing sleeve 3 and the split packing gland 10. An annular groove is added to the packing sleeve 3. Due to the centrifugal force, the leaked molten salt will be thrown into the liquid accumulation tank on the split packing gland 10. The liquid position sensor 14 is arranged on the liquid accumulation tank to monitor whether there is molten salt medium in the liquid accumulation tank of the split packing gland 10 and send a signal to the control system. When the sensor detects that there is molten salt medium in the liquid accumulation tank of the split packing gland, the system will start an alarm to remind the maintenance personnel to check the copper packing.

[0035] This invention uses sensors and a control system alarm to monitor whether the packing is operating healthily.

[0036] This invention solves the problems of easy seizing and damage of the packing seal threads in high-temperature molten salt pumps; the difficulty in disassembling the packing gland and packing ring; and the problem of automatic monitoring of the operational health of copper packing, thereby achieving the goal of reducing equipment maintenance time and lowering maintenance costs.

[0037] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as defined by the appended claims and their equivalents.

Claims

1. A packing seal structure for a vertical high-temperature molten salt pump, characterized in that: The packing seal structure for a vertical high-temperature molten salt pump includes: a shaft, a retaining ring, a packing bushing, a stuffing box, copper packing, a segmented porous packing ring, a key, a segmented packing gland, a liquid position sensor, and a temperature sensor. The copper packing and the segmented porous packing ring are arranged inside the stuffing box and are pressed together by the segmented packing gland. The packing bushing is fixed to the shaft by the key and the retaining ring and rotates with the shaft. The copper packing is in direct contact with the packing bushing, and the gland fixing bolt assembly fixes the packing gland and provides the packing gland with clamping force. The liquid position sensor and the temperature sensor are respectively installed on the segmented packing gland and the stuffing box.

2. The packing seal structure for a vertical high-temperature molten salt pump according to claim 1, characterized in that: The gland fixing bolt assembly includes a union bolt, a pin, a cotter pin, a heat insulation sleeve, and a nut. It is connected to the stuffing box via the pin, and the cotter pin secures the pin. The union bolt is installed on the pin and is fixedly connected to the split stuffing gland via the heat insulation sleeve and the nut.

3. The packing seal structure for a vertical high-temperature molten salt pump according to claim 1, characterized in that: The copper packing is in direct contact with the packing sleeve to prevent the leakage of the internal high-temperature molten salt. When the packing sleeve rotates with the shaft, it generates a large amount of heat due to relative friction with the stationary copper packing. This heat is carried away by the low-temperature compressed air introduced into the segmented porous packing ring from the outside.

4. The packing seal structure for a vertical high-temperature molten salt pump according to claim 1, characterized in that: The segmented porous packing ring is installed inside the stuffing box. It adopts a segmented design, with the outer ring of the segmented porous packing ring fitting tightly with the stuffing box and the inner ring of the segmented porous packing ring leaving a gap between it and the shaft.

5. The packing seal structure for a vertical high-temperature molten salt pump according to claim 1, characterized in that: Copper packing is installed inside the stuffing box, located between the shaft and the stuffing box, and in contact with both the shaft and the stuffing box. The openings of the copper packing are arranged in an alternating pattern.

6. The packing seal structure for a vertical high-temperature molten salt pump according to claim 1, characterized in that: One end of the split packing gland is inserted into the stuffing box, and the other end is connected and fixed to the stuffing box through the gland fixing bolt assembly.

7. The packing seal structure for a vertical high-temperature molten salt pump according to claim 1, characterized in that: The packing bushing is provided with an annular groove, and the split packing gland is provided with a liquid collection groove. The annular groove and the liquid collection groove work together to collect leaked molten salt.

8. The packing seal structure for a vertical high-temperature molten salt pump according to claim 1, characterized in that: The heat insulation sleeve is a porous heat insulation sleeve.

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